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.
-Tesfaye Y,
Lal S Hazard of yawning Canadian Med Assoc J
1990;142(12):15
-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
-Lal S, Y
Tesfaye et al Apomorphine: clinical studies
on erectile impotence and yawning. Prog
Neuropsychopharmacol Biol Psychiatry 1989; 13;
3-4; 329-39
