This is a 63-year-old woman with a 40-year history of severe OCD, with poor response to numerous treatments. For the last 5 years, the patient was receiving fluoxetine 40 mg/day. Owing to a recent severe worsening of her symptoms (Yale-Brown Obsessive-Compulsive Scale score: 32), fluoxetine was replaced by escitalopram up to 60 mg/day, and, within 6 weeks, patient’s symptoms improved moderately (Y-BOCS score: 23). However, she started then to complain of involuntary jaw movements of grinding and clenching her teeth all day long and, as a result, she experienced severe tooth pain and headache. Her examination through the Abnormal Involuntary Movement Scale (AIMS)-section for rating facial and oral movements- yielded a score of 7. Escitalopram was decreased to 40 mg/day for the next 4 weeks without any improvement of her bruxism, and, moreover, with worsening of her OCD symptoms (Y-BOCS score: 27). Fluoxetine up to 60 mg/day was then substituted for escitalopram for another 4 weeks, with an amelioration of her OCD symptoms (Y-BOCS score: 22). However, her bruxism persisted unabated. At that time, aripiprazole 10 mg/day was added to her regimen, and, within 1 week, her bruxism subsided (AIMS facial and oral movements score: 2). The patient was then referred for CBT and, until her last follow-up 6 months later, she remained free from abnormal orofacial movements.