mise à jour du
12 juin 2003
General Hospital Psychiatry 2003;25:217-218
Injured temporomandibular joint associated with
fluoxetine-monotherapy-induced repeated yawning
Pae CU, JJ Kim et al
Department of psychiatry Kangnam St Mary's Hospital Seocho, Korea
Bâillements et stomatologie


Bâillements et dépression - Yawning and depression
Le bâillement: de la physiologie à la iatrogénie
Yawning: from physiology to iatrogenic effect
Some antidepressants; have been used for the treatment of bulimia nervosa (BN) with encouraging results in reducing binge frequency. Among them, fluoxetine bas been proven effective in reducing bulimic symptoms in a long-term (52 weeks) double-blind trial. We present a case report of an injured temporomandibular joint (TMJ) associated with fluoxetine-monotherapy-induced repeated yawning.
1. Case report
A 23-year-old Korean female patient visited our outpatient department because of recently developed depressed mood, impulsiveness, sleep disturbance, and recurrent episodes of binge eating with purging behavior. She was diagnosed as having BN, purging type, according to DSM-IV criteria. She had irregularly visited 2 private practitioners during the previous 9 months before visiting our outpatient department. Examination of her history reveals that antidepressant treatment and cognitive behavioral therapy had been recommended previously, but low motivation for treatment caused her to drop out early from intervention. She did not undergo any psychiatric treatment for about 2 months, even though she experienced increasing episodes of binge eating with purging behavior. The ficquency of binge eating with purging behavior was about 2-3 times per day, for at least 3 days a week during the previous 4 months. She induced vomiting with the right second and third fingers, and according to her history, she did not use laxatives, enemas, or other medication for compensatory behavior to prevent weight gain.
Treatment with fluoxetine 20 mg/d every morning started with the patient's agreement. After 7 days, the fluoxetine dosage was increased to 40 mg/d every morning and maintained. On day 21 after fluoxetine administration, she carefully asked about the side effects of fluoxetine and questioned the treating psychiatrist about the association of excessive yawning with the medication. Her yawning, associated with the mild sedation, started on day 5 after taking fluoxetine. Initially the frequency was 5-10 times per day, and the intensity was mild. At that time, the treating psychiatrist did not consider it an important symptom because the patient reported no other adverse effects, and it was not so severe as to impair routine activity. Therefore, the patient remained on the same medication, and observation was recommended.
On day 42, the patient reported that she had visited a dental clinic due to the progressive nature of the yawning and the accompanying pain and movement dysfunction in both TMJ areas that had been evident since day 35. According to her report, the frequency and intensity of excessive and spasmodic yawning had increased over time. She experienced popping sounds in the jaw joint when opening or closing the mouth and suffered from tenderness in both TMJ areas. The dentist confirmed her injured TMJ on the basis of TMJ x-ray and clinical symptoms and signs. She had no history of trauma on the TMJ or of chronic mouth breathing. Furthermore, she had no habit of clenching or grinding her teeth during stressfül events or when sleeping, except during a period of wearing dental braces 5 years previously.
Therefore, we discontinued fluoxetine administration at that time, although fluoxetine was effective to control her binge eating. At that time, her binge eating was reduced to about 3-4 tintes (sometimes none) per week, and decreasing to about half diet noted on her first visit. Purging behavior also decreased to less than the frequency of binge eating, and she did not feel the impulse to purge for 2 weeks prior to discontinuation of fluoxetine, based on her report. Five days after discontinuation of fluoxetine, the frequency and intensity of yawning began to decrease, and 17 days after discontinuation, she was free from yawning and had diminished pain in both TMJ areas when opening and closing her mouth.
2. Discussion
Fluoxetine-induced yawning bas been reported in some studies, as listed in the literature insert, and fluoxetine has been attributed as causing TMJ injury due to repeated yawning. The temporal relationship between her yawning and the "on-off' administration of the drug seems clear, justifying the conclusion that TMJ injury is due to repeated yawning secondary to administration of fluoxetine. One could raise the possibility that the TMJ injury was caused by excessive purging activity prior to treatment with fluoxetine but not by fluoxetine treatment. This explanation seems less likely, since she did not experience any TMJ injury-related symptoms prior to visiting our clinic, even while she was actively purging, and the purging behavior decreased rather than progressed during treatment with fluoxetine, although marked coincidence and possible injury might be speculated.
Comparing our case with previous reports, it is interesting that the reported onset for our patients who suffered from more severe yawning, resulting in injury to both TMJs was somewhat earlier, while the 2 previous cases exhibited a relatively mild nature and a late onset. As for the relationship between yawning and dosage, our case and another one were started on fluoxetine at 20 mg/d, while the other was started at 40 mg/d. This might suggest that differences in fluoxetine-induced yawning could be due to individual vulnerability. However, we could not confirm underlying triggers or confounding factors in our case. Modell [4) emphasizes that dose seems related to the nature of the yawning.
Although the serotonin antagonist cyproheptadine was first used to treat fluoxetine-induced yawning by Cohen and Modell [4), suggesting that the serotonergic mechanism was directly involved, we do not have strong evidence that fluoxetine-induced yawning could be caused by serotonergic activity alone. It has been proposed that the underlying mechanisms for the yawning are associated with the interaction of several receptor activities [6) and with other biological aspects, such as chronic administration of opiates, rather than with the simple direct involvement of one specific neurotransraitter.
In conclusion further systematic information is needed regarding the relationship between fluoxetine administration and clinically significant yawning. Clinicians should listen carefully to their patients when they describe an unexpected reaction to ensure that it does not pass unnoticed.
Philibert C, Sauveplane K, Pinzani-Harter V et al. Le bâillement: de la physiologie à la iatrogénie. La lettre du pneumologue. 2011;14(5):168-172
Romano SJ, Halmi KA, Sarkar NP, Koke SC, Lee JS. A placebocontrolled study of fluoxetine in continued treatinent of bulimia nervosa after successful acute fluoxetine treatment. Am J Psychiatry 2002;159:96-102.
Fluoxetine Bulimia Nervosa Collaborative Study Group. Fluoxetine in the treatment of bulimia nervosa: a multicenter, placebo-controlled, double-blind trial. Arch Gen Psychiatry 1992;49:139-47.
Cohen AL Fluoxetine-induced.yawning and anorgasmia reversed by cyproheptadine treatment. J Clin Psychiatry 1992;53:174.
Modell JG. Repeated observations of yawning, cliteral engorgement, and orgasm associated with fluoxetine administration. J Clin Psychopharmacol 1989;9W3-5.
Product-literature insert PA 2461 DPP. Indianapolis, IN: Dista Products Co. Division of Eli Lily and Co., 1988.
Kimura H, Yarnada K, Nagashima M, Furukawa T. Involvement of catecholamine receptor activities in modulating the incidence of yawning in rats. Pharmacol Biochem Behav 1996;53:1017-21.
Casas M, Guardia J, Prat G, Trujols J. The apomorphine test in heroin addicts. Addiction 1995;90:831-5.
La luxation de la machoire Mercier J Rev Prat Méd Générale1989; 3; 55 - 1997; 11; 389
Dislocation of the temporomandibular joint due to forceful yawning during induction with propofol Avidan A J Clin Anesth2002; 14; 159
Injured temporomandibular joint associated with fluoxetine-monotherapy-induced repeated yawning Pae CU, JJ Kim et al General Hospital Psychiatry 2003; 25; 217-218
Hazard of yawning Tesfaye Y, Lal S Canadian Med Assoc J 1990; 142: 15
Hazard of yawning Tesfaye Y, Lal S Canadian Med Assoc J 1991; 145; 12; 1560
Integrated jaw and neck function in man. Studies of mandibular and head-neck movements during jaw opening-closing tasks Zafar H Swed Dent J 2000; Suppl 143; 1-41 or Zafar H, Eriksonn PO Arch oral Biology 2000; 45 ; 675-682
Temporomandibular disorders: a clinical update (pdf) George Dimitroulis BMJ1998; 317; 190-194
Clinical TMD, pain related disability and psychological status of TMD patients Yap A, Cha E, Hoe K J Oral Rehabilitation 2002; 29; 374-380
Bilateral dislocation of the mandible 2 cases in a nuclear family Ndiokwelu E. Odontostomatol Trop. 2005;28(112):27-3
A survey of temporomandibular joint dislocation: aetiology, demographics, risk factors and management in 96 Nigerian cases. Ugboko VI et al. Int J Oral Maxillofac Surg 2005;34:499-502
Le bâillement thèse de stomatologie MC Forté, Bordeaux, 1982
Experimental detection of a cervical arousal mechanism of yawning, enhancing intracerebral (CSF) fluid pressure Bouyssou M, Tricoire J J Dental Res 1985; 64; 721
Remarques sur la signification physiologique du bâillement Lepp FH Bull Group Int Rech Sci Stomatol Odontol 1982; 25; 251-290
De la propriété hypnotoxique des humeurs développée au cours d'une veille prolongée Legendre R, Pieron H C.R. Société de Biologie de Paris 1912;72:210-212
Mandibular dislocation from yawning during induction of anesthesia. Unnikrishnan KP, Sinha PK, Rao S. Can J Anaesth. 2006;53(11):1164-5.
Luxation of the mandible in yawning. Myrhaug H. Tidsskr Nor Laegeforen. 1961;81:362-365. (Norwegian)
Impaired jaw function and eating difficulties in whiplash-associated disorders Grönqvist J, Häggman-Henrikson B, Eriksson PO. Swed Dent J. 2008;32(4):171-177.
Retropharyngeal tendinitis: a rare differential diagnosis of severe headaches and neck pain. Harnier S et al. Headache. 2008;48(1):158-161