Keywords

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FormalPara Key Points

  • Oral submucous fibrosis is a chronic condition.

  • It affects not only submucosa of the oral cavity but also involves muscles, bones, and joints surrounding the affected area.

  • Management of dental issues, infections, ulcers, and oral hygiene precedes surgical management of trismus.

Oral submucous fibrosis (OSMF) is a chronic condition of the mouth characterized by juxta-epithelial inflammatory reaction and progressive fibrosis of the submucosal tissues. The fibrosis progresses and affects tissues beyond the submucosa (muscles, bones, and joints), leading to rigidity and inability to open the mouth adequately (trismus). OSMF is considered a premalignant condition. The term oral submucous fibrosis was coined by Dr S.G. Joshi in 1953.

OSMF is associated with betel nut and quid chewing, a common practice in India.

Trismus is a sequel of advanced OSMF. The oral submucosa and mucosa is densely fibrosed, with significant contraction of tissues. The dimensions of all tissues eventually reduce. Muscles contract, lose length, and become fibrotic. The bones may become smaller, and joints may become contracted and lose mobility.

Oral opening reduces significantly in later stages, leading to poor oral hygiene. Gingival and dental infections are common, further leading to inflammation and fibrosis.

Cheeks lose stretchability and upper and lower sulci lose depth, eventually creating acute grooves, difficult to reach while cleaning. The tongue loses bulk, becomes fibrotic, and loses prehensility. It becomes difficult to reach the outer side of the teeth, and the vestibule, with the tongue. This leads to further deterioration of hygiene and eventually further fibrosis.

Contracture bands appear in the mucosa, tightening it. These bands suffer ulcerations and cracks, which get infected, and lead to inflammation and fibrosis. Introducing instruments for maintaining hygiene in the cheeks and oral cavity becomes difficult.

Muscles of mastication and the buccal and facial muscles lose bulk and undergo hypotrophy due to disuse. Fibrosis occurs in these muscles, and eventually they become tight bands.

Bones lose bulk and become weak. Temporomandibular joints suffer contraction and lose excursion, and the joint space eventually reduces in size. Movements of the jaws are reduced, and translation is lost significantly in the later stages of trismus.

Fibrosis may extend to the palatal mucoperiosteum and the soft palate. The soft palate becomes tight, contracted, and smaller in dimension. There may be ulcerations in the palatal mucosa. Uvula becomes contracted and small.

Bands of contracture may extend from soft palate through the retromolar mucosa to the mandibular area, leading to contraction and stiffness of the lower jaw.

Fibrosis may extend to the oropharynx to some extent.

Dental and gingival infections are common and lead to loss of teeth. The gingiva flattens away, and fibrotic ridges form on the alveolus.

In advanced stages, teeth abut against each other, and maxillary and mandibular incisors overlap.