mise à jour du
6 juin 2002
Canadian Med Assoc J
Hazard of yawning
Yoseph Tesfaye, Skorzewska A, Samarthji Lal
Douglas Hospital Research Centre, Verdun, Quebec
Hazard of yawning Tesfaye Y, Lal S
Bâillements et stomatologie


0ur report of a case of jaw subluxation with yawning (Can Med Assoc J 1990; 142: 15) generated reminiscences and some wit from Drs. Richard S. Lurie and Ellen and Leonard Warner (ibid: 533). Data on this phenomenon remain anecdotal, and prevalence studies are lacking. Accordingly, we undertook a survey at Douglas Hospital, Verdun, Que.

Questionnaires were mailed to the 86 active members of the Council of Physicians, Dentists and Pharmacists of the hospital. The ages of the members ranged from 29 to 81 years, and the mean age was 51.2 years. Seventy-two replies (an 84% response rate), 54 from men and 18 from women, were received. In the calculation of percentages nonresponders were considered to be free of mandibular difficulties (i.e., n = 86).

Jaw subluxation was reported by five men and one woman during a total of 19 episodes. For one man a bicycle accident at the age of 21 had resulted in the only incident of jaw subluxation experienced. Another man also had a single episode, the unwelcome result of a passionate kiss at the age of 26. An anterior subluxation of the right temporomandibular joint, presumed to be the local manifestation of ankylosing spondylitis (temporomandibulitis), had occurred more than a year earlier in a 41 year-old man.

The remaining three cases of jaw subluxation were of particular interest as they occurred predominantly or selectively in association with yawning. A 65-year-old man who had suffered at least 10 such events over the previous 12 years attributed most subluxations to yawning and a few to dental procedures. Three episodes of jaw subluxation solely associated with yawns and occurring between the ages of 42 and 53 were reported by a 56-year-old man. The woman had experienced three episodes of jaw subluxation during yawning between the ages of 15 and 45.

The high prevalence of jaw subluxation (7%) was surprising. The prevalence of subluxation associated with yawning was 3.5%, which suggests that naturally occurring jaw subluxation may represent a more common phenomenon than heretofore suspected.

  1. -Tesfaye Y, Lal S Hazard of yawning Canadian Med Assoc J 1990;142(12):15
  2. -Lal S, Tesfaye Y, Thavundayil JX, Skorzewewska A, Schwartz G Effect of time-of-day on yawning response to apomorphine in normal subjects Neuropsychobiology 2000; 41; 4; 178-180
  3. -Lal S, Grassino A, Thavundayil YX, Bubrovsky B A simple method for study of yawning in man induced by the dopamine receptor agonist, apomorphine. Progr Neuropsychopharmacol Biol Psychiatry 1987; 11; 223-228
  4. -Lal S, Y Tesfaye et al Apomorphine: clinical studies on erectile impotence and yawning. Prog Neuropsychopharmacol Biol Psychiatry 1989; 13; 3-4; 329-39
  5. -Skorzewska A, Tesfaye Y , Krishnan B, Schwartz G, Thavundayil J, Lal S Effect of scopolamine on spontaneous yawning in men. Neuropsychobiology 1993; 27; 1; 17-20
  6. -Lal,S. Apomorphine in the evaluation of dopaminergic function in man Prog Neuropsychopharmacol Biol Psychiatry 1988; 12; 2-3; 117-64