Interventions for the management of mandibular fractures

Mona Nasser; Nikolaos Pandis; Padhraig S Fleming; Zbys Fedorowicz; Edward Ellis; Kamran Ali

doi:10.1002/14651858.CD006087.pub3

Interventions for the management of mandibular fractures

Authors' declarations of interest

Version published: 08 July 2013 Version history

https://doi.org/10.1002/14651858.CD006087.pub3

Collapse all Expand all

Abstract

available in

Background

Fractures of the mandible (lower jaw) are a common occurrence and usually related to interpersonal violence or road traffic accidents. Mandibular fractures may be treated using open (surgical) and closed (non‐surgical) techniques. Fracture sites are immobilized with intermaxillary fixation (IMF) or other external or internal devices (i.e. plates and screws) to allow bone healing. Various techniques have been used, however uncertainty exists with respect to the specific indications for each approach.

Objectives

Search methods

We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 28 February 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 1), MEDLINE via OVID (1950 to 28 February 2013), EMBASE via OVID (1980 to 28 February 2013), metaRegister of Controlled Trials (to 7 April 2013), ClinicalTrials.gov (to 7 April 2013) and the WHO International Clinical Trials Registry Platform (to 7 April 2013). The reference lists of all trials identified were checked for further studies. There were no restrictions regarding language or date of publication.

Selection criteria

Randomised controlled trials evaluating the management of mandibular fractures without condylar involvement. Any studies that compared different treatment approaches were included.

Data collection and analysis

At least two review authors independently assessed trial quality and extracted data. Results were to be expressed as random‐effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. Heterogeneity was to be investigated to include both clinical and methodological factors.

Main results

Twelve studies, assessed as high (six) and unclear (six) risk of bias, comprising 689 participants (830 fractures), were included. Interventions examined different plate materials and morphology; use of one or two lag screws; microplate versus miniplate; early and delayed mobilization; eyelet wires versus Rapid IMF™ and the management of angle fractures with intraoral access alone or combined with a transbuccal approach. Patient‐oriented outcomes were largely ignored and post‐operative pain scores were inadequately reported. Unfortunately, only one or two trials with small sample sizes were conducted for each comparison and outcome. Our results and conclusions should therefore be interpreted with caution. We were able to pool the results for two comparisons assessing one outcome. Pooled data from two studies comparing two miniplates versus one miniplate revealed no significant difference in the risk of post‐operative infection of surgical site (risk ratio (RR) 1.32, 95% CI 0.41 to 4.22, P = 0.64, I² = 0%). Similarly, no difference in post‐operative infection between the use of two 3‐dimensional (3D) and standard (2D) miniplates was determined (RR 1.26, 95% CI 0.19 to 8.13, P = 0.81, I² = 27%). The included studies involved a small number of participants with a low number of events.

Authors' conclusions

This review illustrates that there is currently inadequate evidence to support the effectiveness of a single approach in the management of mandibular fractures without condylar involvement. The lack of high quality evidence may be explained by clinical diversity, variability in assessment tools used and difficulty in grading outcomes with existing measurement tools. Until high level evidence is available, treatment decisions should continue to be based on the clinician's prior experience and the individual circumstances.

Plain language summary

available in

Treatments for fractures of the lower jaw

Review question

The lower jaw (also known as the mandible) is an important bone that shapes the face, holds the lower teeth in place and is used to move the mouth, for talking and chewing food. Fractures are most often found in the part of the lower jaw that supports teeth (known as the body), the part where the jaw curves upwards into the neck (the angle), or at the knobbly‐shaped joint found at the very top of the jaw bone (the condyle). Available treatments align and stabilize the fracture, allowing the bone to heal in the proper position. Treatments may or may not involve surgery.

This review, produced by the Cochrane Oral Health Group, examines different methods for treating fractures of the body and angle of the mandible in existing research and studies.

Background

People of all ages can fracture their lower jaw, but fractures mainly occur as a result of violence (for example, being hit or punched in the jaw) or by being involved in an accident on the road (for example, car crashes or bicycle accidents). These fractures can be stabilized by physically binding the jaw shut with a system of bars, wires or elastic bands (intermaxillary fixation), or by using tiny screws or plates attached directly to the fractured sections of the lower jaw bone whilst still allowing the mouth to open (rigid fixation).

Study characteristics

The evidence on which this review is based is up to date as of 28 February 2013. Twelve studies with a combined total of 689 participants were included in this review. Participants ranged in age from 16 to 68 years and most participants (90%) were male. All of the studies compared different types of surgical treatments, and each study evaluated a different aspect of surgical treatment such as different types of plates, screws, or wires or how long the jaw was immobilized after surgery.

Key results

There were concerns about the design and quality of all the studies. All the studies evaluated different aspects of surgical treatment. None of the studies evaluated non‐surgical treatments such as intermaxillary fixation and no study compared surgical treatment with non‐surgical treatment. As a result there is no clear evidence to indicate which approach is the best to manage these fractures.

Quality of the evidence

The quality of the evidence found is poor. Recommendations are made for further well‐conducted research studies in this area to be undertaken.

Authors' conclusions

Implications for practice

There is a shortage of high quality evidence relevant to treatment modalities considered in this review; the effectiveness of interventions for management of mandibular fractures without condylar involvement remains unclear. Clinical decisions regarding the most appropriate management of these cases must be based on clinical experience, and the nature of the presentation taking into account patients' preferences and choices.

Implications for research

While it is accepted that for practical reasons, trials testing surgical interventions are generally less common than therapeutic drug trials, there would appear to be a continuing need for further trials to evaluate the effectiveness of open reduction versus closed treatment of fractured mandibles without condylar involvement. Currently, most of the outcome measurements used in clinical trials are not standardised patient‐oriented outcome measurements. Trialists should first develop a standardised set of patient‐oriented outcomes before conducting further clinical trials. It is important that future trials are robust, well‐designed and reported according to the CONSORT statement (http://www.consort‐statement.org/) or the extensions of the CONSORT statement. They should also carefully consider the IDEAL recommendations for clinical trials evaluating surgical interventions (Ergina 2009; McCulloch 2009). Clear conduct and reporting will enable appraisal and interpretation of results, and accurate judgements to be made about the risk of bias, and the overall quality of the evidence. Although it is uncertain whether reported quality mirrors the true conduct of the study, it is noteworthy that studies with unclear methodology have been shown to produce biased estimates of treatment effects (Schulz 1995). Adherence to guidelines, such as the CONSORT statement, would promote transparent, better and more complete reporting.

A significant drawback of most published studies is that fractures in various locations throughout the mandible are included. It is known that some fractures, for instance those involving the angle of the mandible, have a higher risk of complications than in other locations. Restricting the inclusion criteria in future studies to fractures in specific regions of the mandible will yield more meaningful information. It would also be beneficial if future randomised controlled trials could focus more closely on comparisons of rigid fixation utilising strong plates (the AO technique) with one of the other commonly reported methods (e.g. closed reduction, miniplates or midsized plates).

Other variables that should be controlled or investigated in future studies include: infected and non‐infected fractures, single fractures and multiply‐fractured mandibles, and simple linear or comminuted fractures. Each of these criteria is important to control or analyse or both as they influence the decision to use either closed or open approaches to treatment, the amount of internal fixation hardware required, and timing of interventions.

For further research recommendations based on the EPICOT format (Brown 2006) see Additional Table 6.

Open in table viewer

Table 6. Research recommendations based on a gap in the evidence of effectiveness of interventions for the management of mandibular fractures

Core elements	Issues to consider	Status of the research for this review and recommendations for future research
Evidence (E)	What is the current status of the evidence?	This systematic review includes 12 RCTs on nine comparisons
Population (P)	Diagnosis, disease stage, comorbidity, risk factor, sex, age, ethnic group, specific inclusion or exclusion criteria, clinical setting	Further studies need to transparently report and analyse patients based on the type and severity of fractures. Most of the included studies involved male patients; future studies might consider stratification based on sex
Intervention (I)	Type, duration, prognostic factor	There is limited evidence on different open (surgical) treatments for management of mandibular fractures. There is a need for more research on any type of intervention for the management of mandibular fractures. However, the most fundamental unanswered question remains 'Which approach is most effective open treatment with internal fixation or closed management?'
Comparison (C)	Type, duration, prognostic factor	Rigid fixation versus functionally stable (non‐rigid) fixation The role of post‐operative IMF after ORIF Intraoral versus extraoral surgical approach Locking versus non‐locking screw/plate systems
Outcome (O)	Which clinical or patient‐related outcomes will the researcher need to measure, improve, influence or accomplish? Which methods of measurement should be used?	Patient satisfaction Return to pre‐trauma lifestyle Occlusal outcome Requirement for second intervention
Time stamp (T)	Date of literature search or recommendation	February 2013 (however, there are six trials awaiting assessment)
Study type	What is the most appropriate study design to address the proposed question?	RCT (adequately powered/multicentred) Methods: concealment of allocation sequence Blinding: not possible for patients or operators, however blinding of outcomes assessors and data analysts is important Setting: hospital/university or general practice with adequate follow‐up

IMF= intermaxillary fixation; ORIF = open reduction and internal fixation; RCTs = randomised controlled trials

Background

The mandible or lower jaw is a horse‐shoe shaped bone which articulates with the base of the skull on each end. It is prone to fracture, with inherently weak areas including the condyle, the angle and parasymphysis.

Description of the condition

Aetiology and prevalence

Mandibular fractures are a common form of facial injury in adults and occur most frequently in males during the third decade of life (Adeyemo 2008). There is geographical variation in the causes of mandibular fractures in adults, with interpersonal violence considered the leading cause in Western Europe (Depprich 2007; Dimitroulis 1991); Australia (Schön 2001); USA (Ogundare 2003), and Canada (Sojot 2001). In Asia (Abbas 2003; Ansari 2004; Ba 1999; Klenk 2003) and Africa (Adeyemo 2008) the majority of mandibular fractures are related to road traffic accidents. Other causes include injury from contact sports, falls, work‐related accidents, alcohol and drug abuse in addition to pathological and iatrogenic factors.

Fractures resulting from violence are most commonly associated with the angle region while those related to road traffic accidents usually involve the condyle, body and parasymphysis. Fractures not involving the condylar process of the mandible account for 65% to 75% of the total number of mandibular fractures (Ellis 2005). A minority of mandibular fractures (less than 1%) occur in edentulous patients and many of these involve the mandibular body (Bruce 1993). Mandibular fractures in elderly people are also more likely to be associated with falls (Nishiike 2002) but have also been reported in atrophic edentulous mandibles after the insertion of dental implants (Carls 1996). The majority of mandibular fractures occur at more than one site, typically bilaterally (Kubilius 2009; Ogundare 2003).

Signs and symptoms

Mandibular fractures may present with a variety of signs and symptoms such as pain, swelling, limited jaw movement, bleeding, tenderness and step deformity at the fracture site. Diminished or altered sensation to the lower lip (anaesthesia, hypoaesthesia or paraesthesia) resulting from damage to the inferior alveolar nerve, and associated soft tissue trauma including intraoral bruising, gingival lacerations and sublingual haematoma are also common. Dentoalveolar injuries are often observed with fractures involving the tooth‐bearing regions of the mandible; occlusal derangement may also occur with its severity related to the site and degree of displacement of the fracture.

Description of the intervention

The intervention is aimed at realignment (reduction) of the fractured segments into their normal anatomic positions (Johnson 1999), and prevention of movement by immobilization (fixation) of the fractured bone thereby allowing osseous union to occur (Banks 2001). The ultimate goal is to restore occlusion (bite), mandibular anatomy and jaw function.

Treatment approaches range from conservative non‐invasive management by 'closed' reduction and immobilization using intermaxillary fixation (IMF) to the more invasive surgical 'open' reduction with internal fixation approach. Several key factors can influence the management of mandibular fractures including the location of the fracture and the degree of displacement. In the dentate mandible, reduction must aim to restore good functional occlusion whereas less precise reduction may be acceptable if sections of the body of the mandible are edentulous or lack opposing teeth. In closed (non‐surgical) reduction the bone ends or fragments are realigned either manually or using traction devices without surgically exposing the fracture site, whereas in an open (surgical) reduction the fracture site is surgically exposed during the procedure (Johnson 1999).

A range of options exist for internal fixation of the fractured mandibular segments (van den Bergh 2012). These include transosseous wiring, circum‐mandibular wiring, compression plates, reconstruction plates, miniplates and lag screws (Ellis 1999). Other less commonly used methods include: intra‐ and extra‐ medullary K‐wires, and metallic mesh (Chakraborty 2011) which may involve the simultaneous use of autogenous bone grafts (Basa 1997; Ziębowicz 2006). Titanium miniplates and screws are used extensively for internal fixation. During the last two decades bone plates made of resorbable materials (e.g. polylactic acid, polyglycolic acid, and polydioxanone) have also increased in popularity but are not used much in mandibular fractures. One of the main factors contributing to their popularity is biological degradation, eliminating the potential need for a second operation for plate removal. However, foreign body inflammatory responses have been described with polylactic and polyglycolic implants (Mohamed‐Hashem 2000). In the edentulous or partially‐dentate mandible adjunctive use of dentures, Gunning splints and external fixation appliances may be helpful to stabilize the fracture, although these methods may not be appropriate for grossly displaced fractures of the edentulous mandible, especially those that are atrophic (Barber 2001).

A number of patient and operator related factors may influence the approach to reduction and fixation of mandibular fractures. Patient factors include age, medical health, state of the dentition, degree of fracture displacement or comminution, and the presence and degree of associated trauma and infection. Important operator factors include surgical skills and experience, operating room facilities, and equipment. In addition, the cost of treatment may have direct implications for both patients and operator.

Protocols for managing mandibular fractures are evolving, with traditional treatment involving intraoperative IMF in conjunction with rigid internal fixation. However non‐compression miniplates, which provide only relative stability, have gained in popularity more recently. The importance of intraoperative IMF as an adjunct to facilitate the application of internal fixation has more recently been questioned (Bell 2008; Gear 2005). The use of a single miniplate on the superior border of the mandible is increasingly preferred for management of mandibular angle fractures among American and European surgeons (Gear 2005). Non‐compression plates are also more widely advocated when large bone plates are placed along the inferior border of the mandible. In addition, design changes have been proposed to bone plates for rigid internal fixation to enhance biomechanical characteristics in the symphysis, parasymphysis and mandibular body (Lovald 2009; Madsen 2008). The aim of such systems is to enhance fracture stability, while minimizing the bulk of the implanted plates and improving patient comfort.

Post‐operative complications

Nine possible post‐operative complications in the management of mandibular fractures have been described by the American Association of Oral and Maxillofacial Surgeons and are often used as parameters of care (Meaders 1998):

mobility at fracture site (non‐union or fibrous union)
malocclusion
soft tissue deformity
infection
chronic pain
neurosensory disturbances
tooth loss or vitality loss
inability to chew hard food
need for alternative or additional treatment.

The likelihood of complications increases in older patients with fractures requiring longer stabilization and often accompanied by more post‐operative complications particularly in those patients with a history of systemic health problems and in those treated with open (surgical) reduction. Inflammatory complications may also develop in the elderly more frequently than in other age groups (Pankratov 2000). There is also a higher incidence of non‐union with severely atrophic mandibles. Additional complications which have been reported include fractured plates, persistent anaesthesia/dysaesthesia and osteomyelitis (Eyrich 1997; Luhr 1996).

How the intervention might work

The closed (non‐surgical) reduction technique to a large extent relies on the restoration of the occlusion to achieve correct alignment of the fractured bone segments through IMF with bone or dental ligations or both (Toma 2003). In the open (surgical) technique, alignment of the bone segments can be accomplished by extraoral and transoral approaches to achieve exposure, followed by internal fixation (open reduction and internal fixation (ORIF)) carried out under direct vision (Shetty 2008). Direct exposure of the fracture site may be achieved via an intraoral incision overlying the fracture site; extraorally, via a submandibular (or Risdon) incision; or through an existing laceration where appropriate. A transbuccal approach combining a stab extraoral incision with intraoral exposure is widely used for mandibular angle fractures.

The mechanism of healing of a fracture depends on the method of immobilization used. With non‐rigid fixation methods (e.g. IMF or transosseous wiring) a haematoma is formed in the fracture line, initially emanating from the marrow and later from the periosteum. The haematoma subsequently gives rise to a callus which is responsible for initial stability between the segments. Ultimately, the callus ossifies thereby restoring bony reunion. Rigid fixation methods, usually employed in conjunction with open (surgical) reduction, ensure close proximity of the fracture segments. Minimal callus formation is observed with rigid fixation and the bone heals primarily by remodelling.

Why it is important to do this review

Mandibular fractures are generally treated by either open (surgical) or closed (non‐surgical) reduction techniques followed by external or internal fixation or both. There is still a lack of consensus on several aspects of the management of mandibular fractures i.e. whether and when to use open or closed reduction, the choice of specific fixation techniques or the appropriateness of surgical or non‐surgical interventions for specific types of fractures (Bell 2008; Gear 2005). Patients also require adequate information on the effectiveness, risks, benefits and quality of life implications of each potential treatment option to facilitate informed decision making (Der‐Martirosian 2006; Gironda 2006). We are unaware of the existence of a high quality comprehensive systematic review investigating the effects of interventions used in the management of mandibular fractures, without condylar involvement, in adults.

Objectives

The objective of this review is to provide reliable evidence of the effects of any interventions either open (surgical) or closed (non‐surgical) that can be used in the management of mandibular fractures, excluding the condyles, in adult patients. This could include different techniques to perform the procedure or different products to facilitate the implementation of the procedure.

Methods

Criteria for considering studies for this review

Types of studies

Only randomised controlled trials (RCTs) were considered in this review.

Types of participants

Adults with mandibular fractures excluding unilateral or bilateral condylar involvement, a clinical topic which has been addressed in a prior Cochrane review (Sharif 2010). Studies considering both types of mandibular fractures and reporting separate data for these fractures were included. Initially, subjects over 18 years were to be included but the threshold was reduced to 16 years as adults are usually defined as being over 16 years within health services (see Differences between protocol and review).

Types of interventions

Any form of open or closed reduction and fixation. Studies that compared any two or more methods of management of mandibular fractures were included, however those investigating intentional mandibular fractures i.e. carried out for orthognathic surgery or tumour resection were excluded.

Types of outcome measures

We categorized these as:

patient‐oriented (i.e. of principal interest to patients and reported by them),
clinical (i.e. those which refer chiefly to the success of the intervention in terms of achieving union and healing of the fracture),
process (i.e. complications occurring during surgery or those that might result in the surgery not being completed or both).

Primary outcomes

Patient‐oriented

Restoration and, if reported, the degree of post‐operative function including chewing, swallowing, speech and the ability to wear dentures, if relevant. Interpretation of these data would account for differences in treatment protocols (i.e. with or without IMF). We would consider any validated instruments to measure this outcome.
Facial appearance to include profile considerations, restoration of symmetry and post‐operative scarring.
Impact on well‐being and quality of life assessed using any validated instrument either generic (i.e. Oral Health‐Related Quality of Life (OHRQoL), Oral Health Impact Profile (OHIP)), or specifically targeting patients with a fractured mandible.

Clinical

Proportion of participants with.

A requirement for additional open (surgical) or closed (non‐surgical) interventions (beyond the primary planned treatment protocol) e.g. due to dislocation or failure of fixation. If data were available, these would be divided into minor and major additional treatment and analysed separately over a period of up to 1 year post‐intervention.
Duration and intensity of post‐operative pain assessed with any recognised and validated pain rating scale to include change from baseline to clinically relevant post‐operative time points. Pain relief and its impact (e.g. type, number and frequency of analgesic consumption to reduce pain/discomfort post‐intervention).
Post‐operative adverse events and complications. If data were available, these would be categorised according to their impact on daily life (i.e. major, moderate and minor), and analysed separately over up to 1 year post‐intervention.

As an outcome 'status of the occlusion', if adequately achieved should restore the individual's ability to chew and speak, in addition to improving facial appearance. Therefore, it should be considered a surrogate outcome and was not included as one of the primary outcomes for this review.

Secondary outcomes

Process

Intraoperative complications. Subject to availability of data, we would differentiate between complications resulting in a change, or those resulting in no change to the treatment protocol.
Drop‐out rate due to protocol deviation.

Search methods for identification of studies

Electronic searches

To identify studies to be included or considered for this review, detailed search strategies were developed for each database. These were based on the search strategy developed for MEDLINE (Appendix 1) but revised appropriately for each database.

We searched the following databases:

Cochrane Oral Health Group's Trials Register (to 28 February 2013) (Appendix 2)
Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 1) (Appendix 3)
MEDLINE via OVID (1950 to 28 February 2013) (Appendix 1)
EMBASE via OVID (1980 to 28 February 2013) (Appendix 4).

The MEDLINE search strategy was combined with the Cochrane Highly Sensitive Search Strategy (CHSSS) for identifying randomised trials in MEDLINE: sensitivity maximising version (2008 revision) as referenced in Chapter 6.4.11.1 and detailed in box 6.4.c of theCochrane Handbook for Systematic Reviews of Interventions, Version 5.1.0 (updated March 2011) (Higgins 2011). The search of EMBASE was linked with the Cochrane Oral Health Group's search strategy for identifying randomised controlled trials in EMBASE (Appendix 4).

Searching other resources

The reference lists of relevant articles were examined and the investigators of included studies were contacted by electronic mail for details of additional published and unpublished trials.

Handsearches

Handsearching was conducted as part of the Cochrane Worldwide Handsearching programme (see the Cochrane Masterlist for details of journals currently being searched).

Ongoing trials

We searched the following trials registries for ongoing trials:

The metaRegister of Controlled Trials on http://www.controlled‐trials.com/ (up to 7 April 2013)
ClinicalTrials.gov: http://www.clinicaltrials.gov/ (up to 7 April 2013)
The WHO International Clinical Trials Registry Platform: http://who.int/ictrp/en/ (up to 7 April 2013).

Language

There were no language restrictions on studies for inclusion. Translation of non‐English language papers was carried out by the authors or with assistance.

Data collection and analysis

Selection of studies

Four review authors (Nikolaos Pandis (NP), Padhraig S Fleming (PSF), Kamran Ali (KA) and Mona Nasser (MN)), independently assessed the abstracts of studies resulting from the searches in duplicate. Full copies were obtained of all relevant and potentially relevant studies, those appearing to meet the inclusion criteria, or for which there were insufficient data in the title and abstract to make a clear decision. The full‐text papers were assessed independently by the review authors and any disagreement on the eligibility of included studies was resolved by discussion or in consensus or both with two other review authors (MN, Zbys Fedorowicz (ZF)). All irrelevant records were excluded and the details and the reasons for their exclusion are outlined in the Characteristics of excluded studies section of the review. For further details see study flow diagram (Figure 1).

Figure 1

Study flow diagram.

Data extraction and management

Study details and outcome data were collected independently and in duplicate by four review authors (NP, ZF, MN, PSF) using a predetermined form designed for this purpose and were entered into the Characteristics of included studies tables in RevMan 5.2 (RevMan 2012). Disagreements were discussed and data were only included if there was an independently reached consensus.

The following details were extracted if reported.

Trial methods: method of allocation, masking of participants and outcomes, exclusion of participants after randomisation and proportion of losses to follow‐up.
Participants: country of origin and study setting, sample size, age, sex, inclusion and exclusion criteria.
Intervention: type, duration and length of time of follow‐up.
Control: any comparisons between different methods of management.
Outcomes: as described in the Types of outcome measures section of this review.
Sources of funding.

The review authors used this information to help them assess heterogeneity and the external validity of the included trials.

Assessment of risk of bias in included studies

Three review authors (NP, PSF, MN) independently assessed risk of bias in the included trials in duplicate using the Cochrane Collaboration's tool for assessing risk of bias as described in section 8.5 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). The gradings were compared and inconsistencies in the assessments between the review authors were discussed and resolved. The following domains were graded as being at low, high or unclear risk of bias:

sequence generation;
allocation concealment;
blinding (of participants, personnel and outcome assessors);
incomplete outcome data addressed;
free of selective outcome reporting;
free of other bias.

These assessments are reported in the risk of bias table for each individual study in the Characteristics of included studies section of the review. See also Figure 2 and Figure 3.
The overall risk of bias of each of the included studies was categorised and reported as follows:

Figure 2

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Figure 3

Risk of bias summary: review authors' judgements about each risk of bias item for each included study.

low risk of bias (plausible bias unlikely to seriously alter the results) if all criteria were met;
unclear risk of bias (plausible bias that raises some doubt about the results) if one or more criteria were assessed as unclear; or
high risk of bias (plausible bias that seriously weakens confidence in the results) if one or more criteria were not met.

See Risk of bias in included studies section of the review.

Measures of treatment effect

Risk ratios and 95% confidence intervals were calculated for all dichotomous primary and secondary outcomes and mean differences with 95% confidence intervals for continuous data.

Unit of analysis issues

We anticipated that some of the included studies may present data from repeated and/or multiple site observations on participants which may lead to unit of analysis errors, if so we followed the advice provided in section 9.3.4 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011).

Dealing with missing data

In studies where data were unclear or missing the principal investigators were contacted. If data were unavailable we followed the advice given in section 16.1.2 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We had concerns about missing data in two studies (Bhatt 2010; Siddiqui 2007); these issues were discussed in the review.

Assessment of heterogeneity

Given that the review question is broad, we expected a degree of clinical diversity between the studies included in this review. Clinical heterogeneity was assessed by examining the characteristics of the studies, the similarity between the types of participants, interventions and outcomes as specified in the criteria for included studies. Statistical heterogeneity was assessed using the I² statistic (Higgins 2003) using the following values for the interpretation of results:

0% to 40%: might not be important;
30% to 60%: may represent moderate heterogeneity;
50% to 90%: may represent substantial heterogeneity;
75% to 100%: considerable heterogeneity.

However, we recognize that this is a general guide to interpreting the results and inconsistency will depend on a number of other factors.

Assessment of reporting biases

If a sufficient number of studies evaluating similar interventions had been identified for inclusion in this review (> 10) we planned to assess publication bias according to the recommendations on testing for funnel plot asymmetry (Egger 1997) as described in section 10.4.3.1 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). If asymmetry was identified, we would attempt to assess other possible causes exploring these in the discussion section, if appropriate.

Data synthesis

If future updates include a sufficient number of studies (> 2) investigating similar interventions allowing pooling of outcome data, we plan to implement fixed‐effect and random‐effects models, as appropriate. If we establish heterogeneity between the studies, a random‐effects model will be used, however if the heterogeneity between the studies is more significant, we will explore the data to explain this and may not undertake a meta‐analysis (section 9.5 of the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0 (Higgins 2011)). If sufficient data were available, we calculated a pooled estimate of effect of specific interventions together with their corresponding 95% confidence intervals (CI).

Subgroup analysis and investigation of heterogeneity

If a sufficient number of studies (> 3) examining similar interventions had been included with moderate, substantial or considerable heterogeneity (Assessment of heterogeneity), we planned to investigate heterogeneity carrying out subgroup analyses based on:

severity of the fracture;
location of the fracture;
gender and age;
socioeconomic status of the participants.

Sensitivity analysis

We had planned to conduct sensitivity analyses to assess the robustness of the overall results by repeating the analyses with the following adjustments:

exclusion of trials with unclear or high risk of bias for allocation concealment;
exclusion of trials with unclear or a high risk of bias for blinding; and
adjusting for missing data or difficulties encountered in data extraction.

If a sufficient number of studies were included, consideration would be given to undertaking sensitivity analyses to examine the effect of completeness of follow‐up using best‐worst and worst‐best case scenarios.

Results

Description of studies

Results of the search

The electronic searches retrieved 830 studies (510 records after de‐duplication). The titles and abstracts were examined for eligibility and those not matching the inclusion criteria were eliminated. We obtained full‐text articles of the 54 remaining studies and subjected them to further evaluation. After further assessment, we eliminated 36 of these studies; the reasons for their exclusion are reported in the Characteristics of excluded studies table. In six studies, several key methodological features were not reported and it was unclear whether they were randomised controlled trials. We also identified one ongoing study on the Clinical Trials Registry website. We contacted the authors for further information and categorized them as awaiting assessment and ongoing studies until a response is received. Details are available at Characteristics of studies awaiting classification and Characteristics of ongoing studies. Twelve studies were therefore included overall.

For further details see study flow diagram (Figure 1).

Included studies

Twelve studies were included in this review (Characteristics of included studies table).

Characteristics of the trial settings and investigators

All of the studies were carried out by consultants or specialists based in university hospitals' oral maxillofacial departments or specialised units in India (six), UK (two), USA (two), Germany (one) and Egypt (one). Recruitment and enrolment of participants took place over time periods ranging from 1 to 6 years. Study end‐points varied from 1 week to 6 months: 1 week to 2 months (Emam 2012), 6 weeks (Collins 2004), 2 months (Bhatt 2010 and Jain 2010), 3 months (Agarwal 2011; Siddiqui 2007; Sugar 2009 and Singh 2012), and 6 months (Gupta 2012; Kaplan 2001 and Schierle 1997). However, one study was confined to the intraoperative time period only (Pigadas 2008).

Characteristics of the participants

A total of 689 participants with ages ranging from 16 to 68 years with 830 fracture sites were included. The gender distribution was not given in one study (Gupta 2012); however, there were (618 males and 51 females in the other studies). Three studies (Agarwal 2011; Pigadas 2008 and Singh 2012) did not report separate details for specific fracture sites; in a further study a distinction was not made between symphyseal and parasymphyseal fractures (Gupta 2012). In the remaining studies fractures of the angle (346/547 = 63.3%) were the most common, followed by the parasymphysis (115/547 = 21.0%), body (36/547 = 6.6%), symphysis (11/547 = 2.0%) and other associated fractures (39/547 = 7.1%).

Characteristics of the interventions

All of the included studies evaluated different types of open interventions against each other. There were no studies comparing different types of closed interventions with one another or comparing open and closed interventions.

Specific interventions assessed for the management of mandibular fractures excluding the condyle included:

2 mm locking titanium plates versus 2 mm non‐locking titanium plates (Agarwal 2011; Collins 2004)
2 mm titanium plates versus 2.5 mm bioresorbable plates (Bhatt 2010)
two lag screws versus one lag screw (Emam 2012)
3‐dimensional (D) miniplates versus standard Champys plates (Jain 2010; Singh 2012)
microplate versus miniplate (Gupta 2012)
immediate mobilization versus 2 weeks delayed mobilization in patients with 2 mm titanium miniplates (Kaplan 2001)
intraoperative Rapid IMF™ versus eyelet wire ties (following open reduction) (Pigadas 2008).

Interventions considered for the management of fractures of the angle of the mandible only were:

two miniplates versus one miniplate and two screws (Schierle 1997; Siddiqui 2007)
one transbuccal miniplate combined with an intraoral approach versus intraoral alone approach (Sugar 2009).

All studies with the exception of Gupta 2012 and Schierle 1997 used some form of external fixation. In several studies this was applied solely as intraoperative temporary IMF (Jain 2010; Kaplan 2001; Siddiqui 2007); in the remainder it was used for extended post‐operative periods, although it was used for just 5 days by Singh 2012. IMF was used in conjunction with elastics for 7 to 10 days in Agarwal 2011, and archbars were used with IMF for 2 weeks in the resorbable plate group in Bhatt 2010. External fixation with arch bars and IMF was used in the single lag screw group in Emam 2012, and Rapid IMF™ or eyelet wiring in one of each of the intervention groups in Pigadas 2008. Although both intervention groups underwent IMF for 4 weeks in Collins 2004, the method used to achieve fixation was not reported.

Characteristics of the outcomes

One of the included studies (Bhatt 2010) evaluated all nine complications described by the American Association of Oral and Maxillofacial Surgeons (Meaders 1998) related to the management of mandibular fractures. Many of the key outcomes for this review such as infection, swelling, nerve injury, segmental mobility, non‐union, malocclusion, plate exposure and removal, and assessment of the need for further surgical intervention, were common across the studies although they were assessed at varying points in time and frequently reported merely as present or absent, without describing the nature and severity of the specific complication.
Post‐operative follow‐up periods varied; in most of the studies weekly follow‐up was undertaken for the first 2 months up to a maximum end‐point of 6 months (Gupta 2012; Kaplan 2001; Schierle 1997). In three studies (Collins 2004; Schierle 1997 and Siddiqui 2007) there were no intermediate post‐operative assessments, and one study (Pigadas 2008) reported intraoperative assessments only.

Primary outcomes

Patient‐oriented

Restoration of function and, if reported, the degree of function re‐established (seven studies). Inability to chew was assessed in one study (Bhatt 2010); malocclusion and occlusal discrepancies in six studies (Agarwal 2011; Bhatt 2010; Emam 2012; Schierle 1997; Siddiqui 2007; Sugar 2009). Surrogate outcomes of bite force measurement assessed in Agarwal 2011; Gupta 2012 and interincisal mouth opening in Sugar 2009.
Facial appearance to include profile, post‐operative scarring and cosmetic appearance (two studies: Bhatt 2010; Siddiqui 2007).
Impact on well‐being and quality of life assessed using any validated instrument (no studies).

Clinical

Proportion of participants with.

A requirement for additional surgical or closed (non‐surgical) interventions (seven studies: Bhatt 2010; Collins 2004; Jain 2010; Kaplan 2001; Schierle 1997; Siddiqui 2007; Sugar 2009).
Post‐operative pain (four studies: Agarwal 2011; Bhatt 2010; Emam 2012 and Kaplan 2001), however the methods of assessment, other than reference to a standard VAS, were not clearly described. Assessments of pain were not carried out in the remaining studies.
Post‐operative adverse events and complications (11 studies). These were assessed in all studies except Pigadas 2008.

Secondary outcomes

Process

Intraoperative complications (three studies: Bhatt 2010; Emam 2012; Pigadas 2008).
Drop‐out rate due to protocol deviation (Collins 2004).

Excluded studies

Thirty‐six studies were excluded. The reasons for their exclusion are reported in the Characteristics of excluded studies table.
A further six studies are awaiting classification.

Risk of bias in included studies

None of the 12 studies met all of the criteria, across all of the domains, that would permit a judgement of low risk of bias. In the overall rating of the risk of bias, half of the studies (Gupta 2012; Jain 2010; Kaplan 2001; Pigadas 2008; Singh 2012; Sugar 2009) were categorised as at 'unclear risk' (plausible bias that raises some doubt about the results) because one or more criteria were assessed as unclear. The remaining studies (Agarwal 2011; Bhatt 2010; Collins 2004; Emam 2012; Schierle 1997; Siddiqui 2007) were judged to be at 'high risk' of bias as one or more of the criteria were not met. Further details of these assessments are given in the risk of bias table corresponding to each study in the Characteristics of included studies tables. Overall ratings are also presented in the risk of bias graph (Figure 2) and the risk of bias summary (Figure 3).

Allocation

The methods used to generate the allocation sequence and the method of concealing the sequence, such that participants and investigators enrolling participants could not foresee the upcoming assignment, are the most important and sensitive indicators for minimising bias in a clinical trial (Schulz 1995). The method of sequence generation was reported adequately in only five of the 12 trials; in the remainder it was not described at all or was, at best, unclear. Concealment of the allocation sequence was reported adequately in only two trials (Gupta 2012; Pigadas 2008).

Blinding

Whilst the challenges of blinding participants and personnel to the interventions considered in this review are recognised, few of the studies attempted to ensure that the outcome assessments were independent of the investigators. Consequently, in most of the studies, it was unclear if foreknowledge of the allocated interventions by participants and personnel could have been prevented during the study (performance bias), therefore the judgement given for this domain was 'unclear' with the exception of one (Bhatt 2010). In the latter study, it was explicitly stated that "blinding was not used", therefore a judgement of 'high risk' of bias was given. As the investigators in most of the studies were the outcome assessors and were generally not 'blinded' to the allocated interventions (detection bias) a judgement of 'high risk' of bias was given for this domain in six of the studies, with a further four judged 'unclear' (Gupta 2012; Pigadas 2008; Singh 2012 and Sugar 2009) and only the remaining two scored as 'low risk' (Jain 2010 and Kaplan 2001).

Incomplete outcome data

In the majority of studies incomplete outcome data appear to have been adequately addressed; missing data were reasonably well‐balanced across intervention groups with similar reasons for absent data across groups. However, in two studies (Bhatt 2010; Siddiqui 2007) there were substantial losses to follow‐up and the explanation and reporting of missing outcome data were largely inadequate, therefore these studies were adjudged to be at 'high risk' of bias for this domain.

Selective reporting

Although study protocols were unavailable for any of the studies, in general the outcomes listed in the 'Methods' section were comparable to the reported results.

Other potential sources of bias

There did not appear to be any reason for concern about other potential sources of bias in any of the included studies.

Effects of interventions

All 12 studies included in this review evaluated the effects of open (surgical) interventions to manage mandibular fractures, the majority used some form of external fixation (i.e. IMF, eyelet wiring with or without archbars and elastics). Three (Schierle 1997; Siddiqui 2007; Sugar 2009) of the 12 studies evaluated the effects of interventions in which only the mandibular angle was involved, eight included participants with fractures at multiple sites, some of which included the angle, and one study was confined to analysis of symphyseal and parasymphyseal fractures (Gupta 2012).

Comparisons of interventions for the management of multiple mandibular fractures not involving the condyles

1. Locking titanium plates versus non‐locking titanium plates

Two studies compared the effects of these interventions (Agarwal 2011; Collins 2004).

Primary outcomes

Patient‐oriented

Restoration and, if reported, the degree of function to include chewing, swallowing, speech and the ability to wear dentures

Although one of the studies (Agarwal 2011) reported bite force measurements as an outcome, this related to the ability of the plates to withstand masticatory loads during function and, although not directly relevant to this outcome, constitutes a surrogate or proxy outcome. The investigators indicated that functional occlusion was achieved in all participants in both intervention groups, however the measurement of this outcome was not clearly reported.

Facial appearance

Nothing reported in either of the included studies.

Impact on well‐being and quality of life

Nothing reported in either of the included studies.

Clinical

Requirement for additional open (surgical) or closed (non‐surgical) interventions

Only one of the studies (Collins 2004) provided data for this outcome; 6/122 participants had minor complications (three in each group): five required surgical removal of the locking plates, and one post‐operative malocclusion was managed with elastic traction and occlusal equilibration.

Post‐operative pain (duration and intensity) and pain relief (including impact)

Agarwal 2011 indicated that there was a significant decrease in pain measured as visual analogue scale (VAS) scores from week 1 to follow‐up at 3 months and, although they reported that there was no difference between the groups at the follow‐up visits, no data were presented in support of these conclusions.

Post‐operative adverse events and complications

In Agarwal 2011 at 3‐week follow‐up, paraesthesia occurred in one participant in the non‐locking plate group although this resolved at 3 months. No paraesthesia was noted in the locking plate group. Infection rates were similar in each group at 6 weeks and at 3 months, and post‐operative swelling persisted in 20% of participants in both groups at weeks 1 and 3, reducing to 10% in the locking plate group at 3 months. The intergroup differences for these complications were not reported as being significant. The investigators indicated that there was no significant difference in the mobility of fracture segments between the groups but provided no supporting data. At the 6‐week follow‐up in Collins 2004 there was no reported difference in risk of infection, between the intervention groups (odds ratio (OR) = 0.90, 95% confidence interval (CI) 0.1 to 7).

Secondary outcomes

Only one of the studies (Collins 2004) comparing these interventions reported data for one of the secondary outcomes prespecified for this review.

Process

Drop‐out rate due to protocol deviation

Early, from hours up to 2 weeks, premature removal of IMF was reported in 13 of the 90 participants analysed. However, the report provided limited details other than the participants themselves releasing their IMF or indicating "the wires fell off" (Collins 2004).

2.Titanium plates versus bioresorbable plates

One study compared these interventions (Bhatt 2010). Substantial (38%) and unbalanced losses to follow‐up at the 2‐month recall provided data that were largely unusable and should be considered unreliable, therefore we report only the assessments obtained 1 month post‐operatively.

Primary outcomes

Patient‐oriented

Restoration and, if reported, the degree of function to include chewing, swallowing, speech and the ability to wear dentures

At the first month follow‐up visit 17/20 (85%) patients per group returned for assessment and there was no difference between the intervention groups in the proportion of participants 3/17 (risk ratio (RR) = 1, 95% CI 0.23 to 4.27) in each group unable to chew hard food. It was not clear whether a validated tool was used to assess this outcome.

Facial appearance

Not reported.

Impact on well‐being and quality of life

Not reported.

Clinical

Requirement for additional open (surgical) or closed (non‐surgical) interventions

Plate removal was statistically more likely in the titanium group (Fisher's exact test: P < 0.05) with infection leading to plate removal in one participant in the titanium group 2 months post‐operatively. A further 4/21 (19%) participants, with six fracture sites, in the same intervention group required re‐operation for plate removal. Additional surgery was not required in any participant in the resorbable group, although two participants required maxillomandibular fixation (MMF) for an additional 2 weeks.

Post‐operative pain (duration and intensity) and pain relief (including impact)

Although there were some losses to follow‐up, 4/21 (19.0%) in the titanium group and 2/19 (10.5%) in the resorbable group, at the 1‐month recall, we were able to re‐analyse the individual patient data provided by the investigators. The proportion of participants with no pain was 7/21 (33.3%) and 8/19 (42.1%) in the titanium and resorbable groups, respectively (RR = 1.26, 95% CI 0.57 to 2.82) . Mild pain occurred in 9/21(42.9%) participants in the titanium group compared to 6/19 (31.6%) in the resorbable group (RR = 0.74, 95% CI 0.32 to 1.68). Moderate pain was experienced in 1/21(4.8%) in the titanium and 2/19 (10.5%) in the resorbable group (RR = 2.9, 95% CI 0.22 to 22.5). Severe pain was unique to participants in the resorbable group 1/19 (5.3%) (Additional Table 1). However, the investigators did not accurately report the methods used to evaluate pain severity in their studies. Consequently we are unable to speculate on the reliability of the pain assessment techniques. Therefore, the outcome data reported in this review are restricted to the proportion of participants with residual pain (of any degree of severity) at the 1‐month recall visit.

Open in table viewer

Table 1. Chronic pain scores (month 1) at participant level (Bhatt 2010)

Pain level	No pain n (%)	Mild n (%)	Moderate n (%)	Severe n (%)
Titanium group*	7/21(33.3%)	9/21 (42.9%)	1/21 (4.8%)	0/21(0.0%)
Resorbable group	8/19 (42.1%)	6/19 (31.6%)	2/19 (10.5%)	1/19 (5.3%)
RR (95% CI)	1.26 (0.57 to 2.82)	0.74 (0.32 to 1.68)	2.9 (0.22 to 22.5)	n/a
RD (95% CI)	8.8% (‐21.2% to 39.87%)	‐11.3% (‐41.0% to 18.5%)	6.35% (‐10.7 to 22.2%)	5.3% (‐4.7% to 15.3%)
P value	0.70	0.62	0.61**	0.49**

CI = confidence interval; RD = risk difference; RR = risk ratio
* referent
** P value based on Fisher's exact test, otherwise based on Pearson Chi² test

Post‐operative adverse events and complications

Dehiscence occurred in 3/32 (9.4%) sites in the titanium group and 5/25 (20%) in the resorbable group within the first few weeks post‐operatively, although this resolved with antibiotic therapy and local measures. Outcomes for several parameters of care according to the American Association of Oral and Maxillofacial Surgeons were measured (Additional Table 2 and Table 3). In the immediate post‐operative period, mental nerve paraesthesia occurred in 18/32 (56.3%) titanium sites and 21/25 (84%) sites in the resorbable group. Neurosensory disturbances, reported at the 1‐month post‐operative recall, decreased slightly with 13/32 (40.6%) versus 18/25 (72.0%) in the titanium and resorbable groups affected, respectively (Additional Table 2).
At 1‐month post‐operatively, the risk of mobility expressed as the risk difference (RD) was 17.8%, and moderate soft tissue deformity (RD = 12.5%) were higher in the resorbable group, whereas the risk of chronic infection (RD = ‐3.1%) was higher in the titanium group. Small differences in risk of malocclusion (2.0%) or inability to chew hard foods (1.5%) were observed between the intervention groups. Additionally, no complications necessitating re‐operation and need for alternative treatment in either group were reported 1 month post‐operatively (Additional Table 3).

Open in table viewer

Table 2. Post‐operative neurosensory disturbances per site (Bhatt 2010)

		Immediate	1 month
		n (%)	n (%)
Neurosensory disturbances	Titanium group*	18/32 (56.3%)	13/32 (40.6%)
Neurosensory disturbances	Resorbable group	21/25 (84.0%)	18/25 (72.0%)
	RR (95% CI)	1.49 (1.05 to 2.12)	1.77 (1.09 to 2.88)
	RD (95% CI)	27.7% (5.3% to 50.1%)	31.4% (6.9% to 55.8%)
	P value	0.34	0.20
Dehiscence	Titanium group *	3/32 (9.4%)	n/a
Dehiscence	Resorbable group	5/25 (20.0%)	n/a
	RR (95% CI)	2.13 (0.56 to 8.08)	n/a
	RD (95% CI)	10.6% (‐8.0% to 29.3%)	n/a
	P value	0.46**	n/a

CI = confidence interval; RD = risk difference; RR = risk ratio
* referent
** P value based on Fisher's exact test, otherwise based on Pearson Chi² test

Open in table viewer

Table 3. Complications AAOMS parameters (Bhatt 2010)

Complications	Intervention group	1 month
		n (%)	RR (95% CI)	RD (95% CI)	P value
Mobility (per site)	Titanium	2/32 (6.3%)	referent	referent
Mobility (per site)	Resorbable	6/25 (24.0%)	3.84 (0.85 to 17.4)	17.8% (‐0.1% to 36.5%)	0.70*
Malocclusion (per participant)	Titanium	4/21 (19.1 %)	referent	referent
Malocclusion (per participant)	Resorbable	4/19 (21.1%)	1.1 (0.32 to 3.82)	2.0% (‐22.9% to 26.9%)	1*
Moderate soft tissue deformity (per site)	Titanium	1/32 (3.1%)	referent	referent
Moderate soft tissue deformity (per site)	Resorbable	5/25 (15.6%)	6.4 (0.80 to 51.3)	12.5% (0.08% to 33.7%)	0.09*
Chronic infection (per site)	Titanium	1/32 (3.1%)	referent	referent
Chronic infection (per site)	Resorbable	‐	n/a	(‐3.1%)
Inability to chew hard food (per participant)	Titanium	3/21 (14.3%)	referent	referent
Inability to chew hard food (per participant)	Resorbable	3/19 (15.8%)	1.1 (0.25 to 4.83)	1.5% (‐20.7% to 23.7%)	1*
Need for re‐operation (per site)	Titanium	‐	‐	‐
Need for re‐operation (per site)	Resorbable	‐	‐	‐
Need for alternative treatment (per participant)	Titanium	‐	‐	‐
Need for alternative treatment (per participant)	Resorbable	‐	‐	‐

CI = confidence interval; RD = risk difference; RR = risk ratio

Secondary outcomes

Process

No data were reported for these outcomes.

3. Two lag screws versus one lag screw

Only one study compared these interventions (Emam 2012).

Primary outcomes

Patient‐oriented

Restoration and, if reported, the degree of function to include chewing, swallowing, speech and the ability to wear dentures

The investigators stated that the restoration of the original occlusion, as assessed visually, was similar in both groups (P > 0.05). Occlusal correction was not achieved in just one participant in the two lag screws group. This is not a directly patient relevant outcome. It is a surrogate/proxy outcome that provides indirect evidence on the effect on the patient‐oriented outcomes.

Facial appearance

Not reported.

Impact on well‐being and quality of life

Not reported.

Clinical

Requirement for additional open (surgical) or closed (non‐surgical) interventions

Not reported.

Post‐operative pain (duration and intensity) and pain relief (including impact)

Only "average pain scores", rated "using a scale of 1 to 10", were reported as 6.6 in the two lag screws group and 6.4 in the one lag screw with archbars group at the first week follow‐up visit. After 2 weeks these values were: 2.5 (two lag screws group) and 2.1 (one lag screw group). Confidence intervals were not reported.

Post‐operative adverse events and complications

Three participants in the two lag screws group experienced post‐operative complications: malocclusion (one) and paraesthesia of the mental nerve (two) which resolved after 3 months. There were no reports of post‐operative complications in the one lag screw group.

Secondary outcomes

Process

Intraoperative complications

Drill bit fracture occurred during preparation in one participant in the two lag screws group.

Drop‐out rate due to protocol deviation

Not reported.

4. 3D miniplates versus standard plates

Two studies compared these interventions and provided very limited data for few of the outcomes (Jain 2010; Singh 2012).

Primary outcomes

Patient‐oriented

Restoration and, if reported, the degree of function to include chewing, swallowing, speech and the ability to wear dentures

Nothing was reported other than that all participants in both groups in Jain 2010 had "satisfactory post‐operative occlusion". It is not clear whether this outcome was measured using a validated tool.

Facial appearance

Not reported.

Impact on well‐being and quality of life

Not reported.

Clinical

Requirement for additional open (surgical) or closed (non‐surgical) interventions

In Jain 2010 surgical site infection in 2/20 participants in the 3D miniplates group required wound debridement, drainage, antibiotic therapy and IMF for a 3‐week period; however, no infection was recorded for any of the patients in the standard fixation group. In Singh 2012, the number of patients who required post‐operative MMF were recorded. The trialists waited 24 hours and then assessed the occlusion. Patients with any occlusal discrepancy received IMF for 5 days. In the 3D miniplates group, eight out of 25 patients (32%) required MMF and in the conventional miniplates group 17 out of 25 patients (68%) required IMF (RR = 0.47, 95% CI 0.25 to 0.88, P = 0.01).

Post‐operative pain (duration and intensity) and pain relief (including impact)

Singh 2012 evaluated post‐operative pain using VAS during the first week, fourth week, eighth week and third month after treatment. They reported no significant difference in pain experienced between the groups although details are not provided to verify this.

Post‐operative adverse events and complications

In the 3D miniplates group (Jain 2010) a number of participants experienced post‐operative events: infection (two), segmental mobility (two), proximity to mental nerve or roots of teeth (two), and based on radiological assessment unsatisfactory reduction (one), and unsatisfactory fixation (four). In the standard miniplate group, only one participant had unsatisfactory fixation. The only statistically significant difference between the groups observed was in relation to fixation (t test: P = 0.03). In the Singh 2012 study, two patients in the 3D plate group and three patients in the conventional plate group developed infection. In addition, two complications occurred in the 3D plate group and three in the conventional group.

Pooling of data for post‐operative infection from both studies showed no significant differences between the 3D miniplate and conventional intervention groups (RR 1.26, 95% CI 0.19 to 8.13, P = 0.81, I² = 27%). However, the studies involved only a small number of participants with a low number events. Therefore, these results should be interpreted with caution (Analysis 1.1).

Secondary outcomes

Process

Nothing was reported for any of these outcomes.

5. Immediate versus delayed mobilization after open reduction

One study compared this approach following open reduction (Kaplan 2001).

Primary outcomes

Patient‐oriented

Restoration and, if reported, the degree of function to include chewing, swallowing, speech and the ability to wear dentures

Limited data were provided; at the conclusion of the study all participants indicated that they had returned to their '"baseline bite".

Facial appearance

Not reported.

Impact on well‐being and quality of life

Not reported.

Clinical

Requirement for additional open (surgical) or closed (non‐surgical) interventions

In the IMF intervention group, one (7.7%) participant had a wound infection and plate exposure leading to its subsequent removal 4 months post‐operatively.

Post‐operative pain (duration and intensity) and pain relief (including impact)

Pain was assessed (scale 1 to 10, 1 = no pain, 10 = the worst) and reported as minor in both treatment groups throughout the study, with no significant differences found at any of the three time points (Additional Table 4).

Open in table viewer

Table 4. Pain assessments (Kaplan 2001)

	Immediate release VAS (rated 1 to 10)	IMF VAS (rated 1 to 10)
6 weeks	1.55	1.20
3 months	1.00	2.64
6 months	1.30	2.71
95% confidence interval was not reported.

IMF = intermaxillary fixation; VAS = visual analogue scale (VAS 1 = no pain, 10 = severe pain)

Post‐operative adverse events and complications

One wound separation and one case of infection was reported in the immobilization intervention group. Assessment (scale 1 to 3, 1 = normal, 3 = absent sensation) of the status of the inferior alveolar nerve was undertaken at each post‐operative visit. No statistically significant difference was noted between the intervention groups at the 6‐week (P = 0.76), 3‐month (P = 0.87), or 6‐month (P = 0.99) evaluations. Data for the subjective assessments of trismus (scale 1 to 10, 1 = no problems, 10 = severe) indicated no difference between the two intervention groups at the 6‐week, 3‐ and 6‐month time points (Additional Table 5). Trismus based on recordings of the interincisor distance showed gradual improvement in both groups and was reported as not statistically significant between the groups at the 6‐week (P < 0.43), and 6‐month (P < 0.99) time points.

Open in table viewer

Table 5. Subjective trismus (Kaplan 2001)

	Immediate release VAS (rated 1 to 10)	IMF VAS (rated 1 to 10)
6 weeks	2.00	1.90
3 months	2.00	1.14
6 months	1.60	1.29

IMF = intermaxillary fixation; VAS = visual analogue scale (VAS 1 = no problems, 10 = severe problems)

Secondary outcomes

None of the secondary outcomes for this review were considered by the investigators in this study.

6. Rapid IMF™ versus eyelet wire ties

Only one study involved comparison of these interventions (Pigadas 2008). Although the principal objective was to assess the incidence of surgical glove perforation between the two interventions, the investigators also recorded other intraoperative complications associated with the interventions.

Primary outcomes

None of the primary outcomes were addressed.

Secondary outcomes

Process

Intraoperative complications

In the rapid IMF group, there were 15/60 intraoperative complications; loosening or fracture of the anchorage ties (11), minor gingival lacerations (two), crown dislodgement (one), and fracture of the power chain (one).

Intraoperative complications in the eyelet wire group (6/60) included minor gingival lacerations (five) and loosening of the eyelet wires (one). The investigators reported that although the incidence of complications was significantly lower in the eyelet group (RR = 2.6, 95% CI 1.0 to 7.0, P = 0.036) these did not appear to affect the surgical outcome.

7. One microplate + one miniplate versus two miniplates

Only one study compared the efficacy and stability of one microplate in conjunction with one miniplate versus two miniplates in patients with isolated mandibular fractures in the interforaminal region (Gupta 2012). However, the data reported in the trial did not satisfy our inclusion criteria.

Comparisons of interventions for the management of fractures of the angle of the mandible only

1. Two miniplates (transbuccal) versus one miniplate + two screws (intraoral at external oblique)

Two studies compared these interventions (Schierle 1997; Siddiqui 2007).

Primary outcomes

Patient‐oriented

Restoration and, if reported, the degree of function to include chewing, swallowing, speech and the ability to wear dentures

Only one study(Siddiqui 2007) reported this outcome as subjective and objective assessments of malocclusion, although the methods used in the assessment and the scale used to rate the degree of malocclusion were not reported. Subjective assessments of malocclusion were reported for 3/36 (8.3%) participants in the single miniplate group and 1/26 (3.8%) in the two‐miniplate group (RR = 2.17, 95% CI 0.24 to 19.68). Objective assessment demonstrated malocclusion in 1/36 (2.8%) and 1/26 (3.8%) in the single and two miniplates groups, respectively (RR = 0.72, 95% CI 0.05 to 11.02). This is a surrogate outcome providing indirect evidence on the effect of the interventions on important patient‐oriented outcomes.

Facial appearance

Facial scarring, as a result of access through the transbuccal route, occurred in two participants in the two‐miniplate group (Siddiqui 2007).

Impact on well‐being and quality of life

Nothing was reported in either study.

Clinical

Requirement for additional open (surgical) or closed (non‐surgical) interventions

Schierle 1997 reported infection in one participant in both the single (6.3%) and two (6.7%) miniplates group, leading to surgical removal of hardware after 43 and 47 days, respectively (P = 0.74). Plate removal was necessary in 2/36 (5.6%) in the single miniplate compared with 3/26 (11.5%) in the two‐miniplate group (P = 0.66) in Siddiqui 2007. The pooled estimate from the two studies did not demonstrate a difference in respect of additional surgical interventions (RR = 0.78, 95% CI 0.19 to 3.11).

Post‐operative pain (duration and intensity) and pain relief (including impact)

Neither study reported on this outcome.

Post‐operative adverse events and complications

The only complications reported in Schierle 1997 were infection in one participant (6.3%) in the single miniplate group, and one (6.7%) in the two‐miniplate group with no significant differences between intervention groups (P = 0.74). There were no reports of post‐operative malocclusion or delayed or non‐union of fractures.
In Siddiqui 2007 22/36 (61%) participants in the single miniplate group had one or more complications and 14/26 (54%) in the two‐miniplate group. Lip numbness was assessed both subjectively and objectively. Subjective assessments of numbness constituted 15/36 (41.7%) in the single miniplate group compared to 10/26 (38.5%) in the two‐miniplate group (P = 0.82), and objective assessments revealed 16/36 (44.4%) compared to 8/26 (31.7%), respectively (P = 0.29).
The risk of infection as reported was 4/36 (11.1%) participants in the single miniplate group compared to 4/26 (15.4%) in the two‐miniplate group (P = 0.75); these responded to incision and drainage and antibiotic therapy. Pooling of data for post‐operative infection from both studies revealed no significant differences between the single and two miniplates intervention groups (RR 1.32, 95% CI 0.41 to 4.22; P = 0.64; I² = 0%). However, the studies involved only a small number of participants with a low number events. Therefore, these results should be interpreted with caution (Analysis 2.1).

Secondary outcomes

None of the secondary outcomes were reported in either study.

2. Transbuccal miniplate combined with an intraoral approach versus intraoral alone approach

Only one study investigated these comparisons (Sugar 2009).

Primary outcomes

Patient‐oriented

Restoration and, if reported, the degree of function to include chewing, swallowing, speech and the ability to wear dentures

Persistence of malocclusion and its impact on restoration of function was minimal and was reported in one participant in each intervention group at the 3‐month follow‐up. There was minimal difference in the mean degree of interincisor assessed mouth opening at 3 months between the intervention groups; in the combined approach 37.68 mm (range: 17 to 50 mm) and 38.19 mm (range: 22 to 60 mm) in the intraoral alone. These are surrogate/proxy outcomes providing indirect evidence on the effect of the interventions.

Facial appearance

The investigators reported that no patients were "recorded as having an unsatisfactory scar" but it was unclear how, when and by whom these assessments were made.

Impact on well‐being and quality of life

Nothing was reported.

Clinical

Requirement for additional open (surgical) or closed (non‐surgical) interventions

Plate removal within the first 90 days was required in 17/84 (20%) in the combined approach group compared to 20/56 (36%) in the intraoral only approach group (RR = 0.57, 95% CI 0.33 to 0.98, P = 0.042). Reasons for removal included: infection in 14/17 (82.4%), and non‐union in 3/17 (17.6%) of the participants in the combined approach group. In the intraoral alone group removal was due to infection in 17/20 (85.0%), due to loose screws in 1/20 (5.0%) and due to non‐union in 2/20 (10.0%).

Post‐operative pain (duration and intensity) and pain relief (including impact)

Nothing was reported.

Post‐operative adverse events and complications

There was no statistical difference in infection rates between the respective groups with 8/84 (9%) treated with the combined approach and 11/54 (20%) with the intraoral approach having persistent infection at 3 months subsequent to the procedure (RR = 0.47, 95% CI 0.20 to 1.09, P = 0.071). The rate of non‐union was found to be identical in both groups (3.6%) with 3/84 in the combined group and 2/56 in the intraoral group failing to unite (RR = 1, 95% CI 0.17 to 5.79). One week following the procedure, wound dehiscence was more frequent in the intraoral only group (9/54: 16.7%) than in the combined approach group (10/84: 12%), although this difference was not of statistical significance (RR = 1.4, 95% CI 0.61 to 3.22, P = 0.43). At the end of the first month the rate of dehiscence increased to 25% (14/54) in the intraoral group and 15% (13/84) in the combined approach group (RR = 1.68, 95% CI 0.85 to 3.28, P = 0.13). By the third month, 21% (12/54) of the intraoral alone group had wound dehiscence or granulation tissue or both compared to 9% (8/84) of the combined approach group (RR = 2.33, 95% CI 1.02 to 5.33, P = 0.039).

Secondary outcomes

Nothing was reported for either of the secondary outcomes.

Discussion

The management of mandibular fractures without condylar involvement may be influenced by a range of local conditions and factors which include the degree of displacement, the extent of associated problems and the anatomic location of the fracture. However, in view of the wide range of possible interventions, a number of technical and surgical controversies persist. Although there is a lack of consensus as to whether surgical interventions can give better results than closed (non‐surgical) treatment, there are certain types of fracture that do not lend themselves to treatment by closed (non‐surgical) methods. Consequently, randomised trials comparing all types of mandibular fractures cannot be justified; albeit for the majority of situations (i.e. single fractures, undisplaced fractures or multiple fractures without complications outside the maxillofacial region), randomised controlled trials are the preferred study design to assess the best approach to treatment.

The objectives of this systematic review were to undertake a complete analysis of outcomes both from an objective viewpoint and with respect to patient reports. Given that assessment of key parameters (e.g. occlusion, facial symmetry or nerve function) prior to the event leading to the fracture is impossible, final assessments from a patient's perspective are often essential to gauge the response to interventions. Unfortunately, many of these patient‐reported outcomes were poorly or incompletely described in the included studies or were assessed in a number of different ways. While it is important that future studies do consider patient‐centred outcomes, there is also an onus on investigators to provide consistent and standardised reporting.

The sparsity of evidence identified in this review may reflect a range in the diversity and questionable reliability of the traditional, normative predictors of success. For example, a major outcome in many studies was the need for secondary surgery; an outcome of this nature is likely to be subjective, with different clinicians having individual thresholds for further treatment. In addition, causes of further treatment may vary, ranging from major complications such as non‐union or malunion to minor problems (e.g. infection necessitating plate removal). Furthermore, given that the aetiology of mandibular fractures, particularly multiple fractures, is typically related to significant traumatic episodes, robust analysis can be compromised by difficulty in separating the response to surgery from extraneous physical and psychological injury. Consequently, assessment of pain scores and other patient‐reported outcomes can be complex, and may be confounded by other clinical parameters. Use of strict selection criteria with omission of certain subtypes or causes of injury (e.g. maxillofacial trauma with multiple non‐facial injuries) is therefore important during the conduct of future research.

There is wide agreement that factors, such as the degree of surgical complexity and the possibility of post‐operative complications with either open (surgical) or closed (non‐surgical) treatment, may influence clinical decisions. This review illustrates that there is currently insufficient high quality evidence to support a single approach, either open (surgical) or closed (non‐surgical), in the management of the fractured mandible without condylar involvement. Therefore, until more robust evidence in the form of well‐designed randomised controlled trials is available, treatment decisions will continue to be based on individual circumstances and clinical experience.

Summary of main results

Twelve studies, six of which were assessed as high and six as unclear risk of bias were included. A total of 689 participants aged 16 to 68 years with 830 fractures were investigated. Unfortunately, there were very limited numbers of trials with small sample sizes conducted for each comparison and outcome. Therefore, our results and conclusions should be interpreted with caution.

Interventions and comparisons considered were open reduction involving differing plate materials and morphology (i.e. use of one or two lag screws; early and delayed mobilization; eyelet wires versus Rapid IMF™ and management of angle fractures with intraoral or transbuccal approaches). Patient‐oriented outcomes appear to have been largely ignored and post‐operative pain scores were either unavailable or inadequately reported in the majority of the included studies.

Pooled data for post‐operative infection in two studies indicated no significant difference between the single and two miniplates groups (RR = 1.32, 95% CI 0.41 to 4.22, P = 0.64, I² = 0%). Likewise, no difference in post‐operative infection between use of two 3D and standard (2D) miniplates was determined (RR = 1.26, 95% CI 0.19 to 8.13, P = 0.81, I² = 27%). However the studies involved a small number of participants with a low number of events. Surgical site infection was also reported in other studies but no significant differences were identified.

Overall completeness and applicability of evidence

Although a relatively large number of studies were included in this review, these were of moderate or low quality and reporting of outcome data was suboptimal. Consequently, the overall quality of the evidence was considered to be low, precluding clearcut conclusions in relation to the relative merits of one technique over another. In addition, while there is an increasing emphasis on patient‐reported measures of outcome in health care generally, there was limited consideration given to patient relevant outcomes in the studies included in this review.

Quality of the evidence

Limitations in study design and implementation

Although the overall clinical design of the included studies appeared to be adequate, our assessments of risk of bias revealed limitations in the quality of the studies covering most of the interventions.

There was considerable variation in the reporting of these studies and in particular the methods used to generate the sequence, to conceal the allocation, and the measures taken to blind investigators and participants. These factors, allied to unsuccessful attempts to contact many of the investigators for additional information, created difficulties in making accurate assessments of the risk of bias in some of the included studies.
The inability to blind investigators and outcomes assessors to the interventions, which is considered a valuable step in reducing bias, presented challenges in the design of many of the studies. Data for losses to follow‐up and the final disposition of missing participants, where failure was a key outcome, were additional indicators of a likelihood of biased assessment of the intervention effect. Independent post‐operative evaluation could have helped to limit the effects of subjectivity in the assessment of these outcomes.

Indirectness of the evidence

The objectives of this review were broad, namely to compare the effects of any intervention (open/surgical or closed/non‐surgical) in the management of mandibular fractures without condylar involvements. Some difficulties were encountered in terms of addressing a restricted version of the main review question with regard to criteria including population, intervention, comparator and outcomes. In particular, adolescent patients were included in some studies, there was also a preponderance of males in most studies.

Both mandibular fractures with and without condylar involvement were reported in some randomised controlled trials. Attempts were made to omit these data from the analysis.

In addition, data were absent for many patient‐preferred outcomes, with patient‐centred outcomes largely overlooked and the total absence of any assessments of the impact of interventions on quality of life in the included studies. In certain cases, only surrogate/proxy outcome measurements related indirectly to our patient‐oriented outcomes were reported. One of the included studies evaluated the extent of mouth opening using the interincisor measurement which is a surrogate/proxy outcome of a patient‐oriented outcome on restoration of function (i.e. chewing and speaking). However, the research settings were in general considered appropriate and relevant to the majority of treatment centres undertaking management of mandibular fractures.

Inconsistency of results

The presence of clinical heterogeneity, although to a certain degree expected under the broad scope of the review, and the inability to extract much usable data, made it difficult to further assess the consistency of the results between the studies.

Imprecision of results

The rather limited number of studies, albeit of adequate sample size and duration and examining similar interventions, that were included in this review did not permit any substantive assessment of the degree of precision of effect.

Publication bias

Every effort was made to identify additional published studies. The low number of studies comparing similar interventions did not permit a funnel plot assessment of publication bias (Higgins 2011).

Potential biases in the review process

Strident attempts were made to limit bias in the review process by ensuring a comprehensive search for potentially eligible studies. The authors' independent assessments of eligibility of studies for inclusion in this review and the extraction of data minimised the potential for additional bias beyond that detailed in the risk of bias tables.

Agreements and disagreements with other studies or reviews

While this review only considered randomised controlled trials, a recent systematic review and meta‐analysis (Andreasen 2008) compared healing with open and closed techniques but no randomised controlled trials were included. All of the studies were retrospective and thus their conclusions need to be viewed within the context of being at risk of bias. In addition, the investigators in these studies did not appear to have considered or included any patient‐reported outcomes in their assessments. Consequently, higher complication rates with open techniques are likely to be have been confounded by the use of open techniques in the management of more displaced and complex fractures.
A further review, which included both retrospective and prospective studies, compared outcomes with resorbable plates and screws and involved both traumatic and planned mandibular fractures (e.g. during orthognathic surgery) (Agarwal 2009). A comparison of five outcomes following rigid fixation and mono‐cortical fixation of mandibular fractures were reported in Regev 2010 but both retrospective and prospective studies were included and combined in the meta‐analysis with consideration of outcomes relating to mandibular angle fractures only.

Figure 1

Study flow diagram.

Navigate to figure in ReviewOpen in new tab

Figure 2

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Navigate to figure in ReviewOpen in new tab

Figure 3

Risk of bias summary: review authors' judgements about each risk of bias item for each included study.

Navigate to figure in ReviewOpen in new tab

Analysis 1.1

Comparison 1 3D miniplates versus standard plates, Outcome 1 Post‐operative infection.

Navigate to figure in ReviewOpen in new tab

Analysis 2.1

Comparison 2 2 miniplates versus 1 miniplate + 2 screws, Outcome 1 Post‐operative infection.

Navigate to figure in ReviewOpen in new tab

Table 6. Research recommendations based on a gap in the evidence of effectiveness of interventions for the management of mandibular fractures

Core elements	Issues to consider	Status of the research for this review and recommendations for future research
Evidence (E)	What is the current status of the evidence?	This systematic review includes 12 RCTs on nine comparisons
Population (P)	Diagnosis, disease stage, comorbidity, risk factor, sex, age, ethnic group, specific inclusion or exclusion criteria, clinical setting	Further studies need to transparently report and analyse patients based on the type and severity of fractures. Most of the included studies involved male patients; future studies might consider stratification based on sex
Intervention (I)	Type, duration, prognostic factor	There is limited evidence on different open (surgical) treatments for management of mandibular fractures. There is a need for more research on any type of intervention for the management of mandibular fractures. However, the most fundamental unanswered question remains 'Which approach is most effective open treatment with internal fixation or closed management?'
Comparison (C)	Type, duration, prognostic factor	Rigid fixation versus functionally stable (non‐rigid) fixation The role of post‐operative IMF after ORIF Intraoral versus extraoral surgical approach Locking versus non‐locking screw/plate systems
Outcome (O)	Which clinical or patient‐related outcomes will the researcher need to measure, improve, influence or accomplish? Which methods of measurement should be used?	Patient satisfaction Return to pre‐trauma lifestyle Occlusal outcome Requirement for second intervention
Time stamp (T)	Date of literature search or recommendation	February 2013 (however, there are six trials awaiting assessment)
Study type	What is the most appropriate study design to address the proposed question?	RCT (adequately powered/multicentred) Methods: concealment of allocation sequence Blinding: not possible for patients or operators, however blinding of outcomes assessors and data analysts is important Setting: hospital/university or general practice with adequate follow‐up
IMF= intermaxillary fixation; ORIF = open reduction and internal fixation; RCTs = randomised controlled trials

Table 6. Research recommendations based on a gap in the evidence of effectiveness of interventions for the management of mandibular fractures

Navigate to table in Review

Table 1. Chronic pain scores (month 1) at participant level (Bhatt 2010)

Pain level	No pain n (%)	Mild n (%)	Moderate n (%)	Severe n (%)
Titanium group*	7/21(33.3%)	9/21 (42.9%)	1/21 (4.8%)	0/21(0.0%)
Resorbable group	8/19 (42.1%)	6/19 (31.6%)	2/19 (10.5%)	1/19 (5.3%)
RR (95% CI)	1.26 (0.57 to 2.82)	0.74 (0.32 to 1.68)	2.9 (0.22 to 22.5)	n/a
RD (95% CI)	8.8% (‐21.2% to 39.87%)	‐11.3% (‐41.0% to 18.5%)	6.35% (‐10.7 to 22.2%)	5.3% (‐4.7% to 15.3%)
P value	0.70	0.62	0.61**	0.49**
CI = confidence interval; RD = risk difference; RR = risk ratio * referent ** P value based on Fisher's exact test, otherwise based on Pearson Chi² test

Table 1. Chronic pain scores (month 1) at participant level (Bhatt 2010)

Navigate to table in Review

Table 2. Post‐operative neurosensory disturbances per site (Bhatt 2010)

		Immediate	1 month
		n (%)	n (%)
Neurosensory disturbances	Titanium group*	18/32 (56.3%)	13/32 (40.6%)
Neurosensory disturbances	Resorbable group	21/25 (84.0%)	18/25 (72.0%)
	RR (95% CI)	1.49 (1.05 to 2.12)	1.77 (1.09 to 2.88)
	RD (95% CI)	27.7% (5.3% to 50.1%)	31.4% (6.9% to 55.8%)
	P value	0.34	0.20
Dehiscence	Titanium group *	3/32 (9.4%)	n/a
Dehiscence	Resorbable group	5/25 (20.0%)	n/a
	RR (95% CI)	2.13 (0.56 to 8.08)	n/a
	RD (95% CI)	10.6% (‐8.0% to 29.3%)	n/a
	P value	0.46**	n/a
CI = confidence interval; RD = risk difference; RR = risk ratio * referent ** P value based on Fisher's exact test, otherwise based on Pearson Chi² test

Table 2. Post‐operative neurosensory disturbances per site (Bhatt 2010)

Navigate to table in Review

Table 3. Complications AAOMS parameters (Bhatt 2010)

Complications	Intervention group	1 month
		n (%)	RR (95% CI)	RD (95% CI)	P value
Mobility (per site)	Titanium	2/32 (6.3%)	referent	referent
Mobility (per site)	Resorbable	6/25 (24.0%)	3.84 (0.85 to 17.4)	17.8% (‐0.1% to 36.5%)	0.70*
Malocclusion (per participant)	Titanium	4/21 (19.1 %)	referent	referent
Malocclusion (per participant)	Resorbable	4/19 (21.1%)	1.1 (0.32 to 3.82)	2.0% (‐22.9% to 26.9%)	1*
Moderate soft tissue deformity (per site)	Titanium	1/32 (3.1%)	referent	referent
Moderate soft tissue deformity (per site)	Resorbable	5/25 (15.6%)	6.4 (0.80 to 51.3)	12.5% (0.08% to 33.7%)	0.09*
Chronic infection (per site)	Titanium	1/32 (3.1%)	referent	referent
Chronic infection (per site)	Resorbable	‐	n/a	(‐3.1%)
Inability to chew hard food (per participant)	Titanium	3/21 (14.3%)	referent	referent
Inability to chew hard food (per participant)	Resorbable	3/19 (15.8%)	1.1 (0.25 to 4.83)	1.5% (‐20.7% to 23.7%)	1*
Need for re‐operation (per site)	Titanium	‐	‐	‐
Need for re‐operation (per site)	Resorbable	‐	‐	‐
Need for alternative treatment (per participant)	Titanium	‐	‐	‐
Need for alternative treatment (per participant)	Resorbable	‐	‐	‐
CI = confidence interval; RD = risk difference; RR = risk ratio

Table 3. Complications AAOMS parameters (Bhatt 2010)

Navigate to table in Review

Table 4. Pain assessments (Kaplan 2001)

	Immediate release VAS (rated 1 to 10)	IMF VAS (rated 1 to 10)
6 weeks	1.55	1.20
3 months	1.00	2.64
6 months	1.30	2.71
95% confidence interval was not reported.
IMF = intermaxillary fixation; VAS = visual analogue scale (VAS 1 = no pain, 10 = severe pain)

Table 4. Pain assessments (Kaplan 2001)

Navigate to table in Review

Table 5. Subjective trismus (Kaplan 2001)

	Immediate release VAS (rated 1 to 10)	IMF VAS (rated 1 to 10)
6 weeks	2.00	1.90
3 months	2.00	1.14
6 months	1.60	1.29
IMF = intermaxillary fixation; VAS = visual analogue scale (VAS 1 = no problems, 10 = severe problems)

Table 5. Subjective trismus (Kaplan 2001)

Navigate to table in Review

Comparison 1. 3D miniplates versus standard plates

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Post‐operative infection Show forest plot	2	90	Risk Ratio (M‐H, Random, 95% CI)	1.26 [0.19, 8.13]

Comparison 1. 3D miniplates versus standard plates

Navigate to table in Review

Comparison 2. 2 miniplates versus 1 miniplate + 2 screws

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Post‐operative infection Show forest plot	2	93	Risk Ratio (M‐H, Random, 95% CI)	1.32 [0.41, 4.22]

Comparison 2. 2 miniplates versus 1 miniplate + 2 screws

Navigate to table in Review

Cochrane Review language

Website language

Abstract

Background

Objectives

Search methods

Selection criteria

Data collection and analysis

Main results

Authors' conclusions

Plain language summary

Treatments for fractures of the lower jaw

Visual summary

Authors' conclusions

Implications for practice

Implications for research

Background

Description of the condition

Aetiology and prevalence

Signs and symptoms

Description of the intervention

Post‐operative complications

How the intervention might work

Why it is important to do this review

Objectives

Methods

Criteria for considering studies for this review

Types of studies

Types of participants

Types of interventions

Types of outcome measures

Primary outcomes

Patient‐oriented

Clinical

Secondary outcomes

Process

Search methods for identification of studies

Electronic searches

Searching other resources

Handsearches

Ongoing trials

Language

Data collection and analysis

Selection of studies

Data extraction and management

Assessment of risk of bias in included studies

Measures of treatment effect

Unit of analysis issues

Dealing with missing data

Assessment of heterogeneity

Assessment of reporting biases

Data synthesis

Subgroup analysis and investigation of heterogeneity

Sensitivity analysis

Results

Description of studies

Results of the search

Included studies

Characteristics of the trial settings and investigators

Characteristics of the participants

Characteristics of the interventions

Characteristics of the outcomes

Primary outcomes

Secondary outcomes

Excluded studies

Risk of bias in included studies

Allocation

Blinding

Incomplete outcome data

Selective reporting

Other potential sources of bias

Effects of interventions

Comparisons of interventions for the management of multiple mandibular fractures not involving the condyles

1. Locking titanium plates versus non‐locking titanium plates

Primary outcomes

Secondary outcomes

2.Titanium plates versus bioresorbable plates

Primary outcomes

Secondary outcomes

3. Two lag screws versus one lag screw