The influence of occlusal stabilization appliances on cervical dystonia symptoms.

Objectives: The aim of this study was to assess the therapeutic efficiency of the occlusal stabilization appliance (OSA) in patients with cervical dystonia (CD).

Methods: The study included 11 patients aged between 29 and 80 years, 7 women and 4 men, diagnosed with primary CD. The patients underwent an extra- and intra-oral clinical examination, followed by para-clinical examinations, necessary for the specifications of the OSA. The following data were recorded: demographic parameters, CD duration, management of the disease, dental impression, recording of the centric relationship, recording of the position of the upper jaw with the facial bow. A standardized OSA was manufactured in a private dental laboratory. Patients received instructions for wearing the OSA for 24 hours. Patients filled a questionnaire designed by us, which evaluated the effects of wearing the OSA over a 24-hours period on the symptoms of CD: muscles contraction, pain, discomfort while walking, sleep quality, tremor. The patients kept the dental appliances, and after three months they completed the questionnaire one more time.

Results: The OSA was applied on the lower arch in 3 (27.3%) patients and on the upper arch in 8 (72.7%) patients. The OSA wearing time for the first 24 h was on average 19.2±6 hours. Total relaxation of dystonic muscles was reported by 9 (81.8%) patients, while 2 (18.2%) patients related partial muscle relaxation. Seven (63.6%) patients reported a pain decrease. Increased comfort while walking was observed by 8 (72.7%) patients. Two (18.2%) patients described an increase of sleep quality. In two (18.2%) patients the tremor disappeared. All patients reported difficulties while eating and removed the OSA during meals. Patients who wore the OSA for more hours, experienced a pain decrease (p=0.08), an increase in sleep quality (p=0.1), the disappearance of the tremor (p=0.1). After three months, only seven patients continued to use the OSA. More patients described a pain decrease after three months (5 (71.4%) vs. 4 (57.1%); p=0.5), relaxation of dystonic muscles (7 (100%) vs. 6 (85.7%); p=0.3).

Conclusions: The use of OSA might be beneficial in CD patients, as it reduced the dystonic symptoms, pain severity and improved the quality of sleep.