Torus mandibularis: an unusual cause of obstructive sleep apnea.

A 50-year-old man, who looked much younger than his age, came to our office with a history of snoring and episodes of suspected obstruction during sleep. He also experienced significant daytime somnolence. Otherwise, he was in good health, and his medical history was significant only for knee surgery. He was allergic to penicillin, thiopental sodium, and meperidine. He was a smoker and an occasional alcohol drinker.

Physical examination revealed that the patient was a healthy-looking man who stood 5 feet 6 inches tall and weighed 135 pounds. His external ear canals and tympanic membranes were normal. Intranasally, there was some deflection of the septum to the right, which had narrowed the airway but did not obstruct it. Intraorally, the patient had an extremely large torus mandibularis bilaterally that extended posteriorly to the level of the second molar and displaced the tongue posteriorly (figure). On oral examination, the soft palate could be seen, but the position of the tongue did not allow for visualization of the palatal arches without the use of a tongue depressor. Flexible fiberoptic endoscopy showed a narrowing of the nasopharyngeal inlet. Upon application of Muller's maneuver, there was a total collapse of the airway at the level of the palate and a narrowing of the airway at the level of the tongue base. Findings on laryngeal examination were normal, and the neck was nontender and without a mass.

Polysomnography revealed that the patient's sleep efficiency was 92%. The latency of the first REM sleep was 86 minutes. The patient spent 1% of his sleep in stage 1, 78% in stage II, 2% in stage III, and 10% in the REM stage. His snoring was rated as 8 on a scale of 10. He experienced 117 obstructive apneas and 28 hypopneas, and his combined respiratory index was 24 events per hour. The longest apneic event lasted 55 seconds. All respiratory events were associated with arousals. His baseline oxygen saturation level was 97%; the lowest recorded level during the sleep study was 85%. No electrocardiographic abnormalities were noted during the study.

After a trial of continuous positive airway pressure, the patient showed a significant improvement in his sleep parameters. He was referred to an oral surgeon for removal of the torus mandibularis.

Torus mandibularis is a common benign oral finding, but no one in our group had ever encountered one that was so large that it caused obstructive sleep apnea.

From the Florida Otolaryngology Group, P.A., Winter Park, Fla.