According to a retrospective demographic and clinical review of patients with oromandibular dystonia (OMD) published in the Journal of Movement Disorders, OMD is highly common in females and generally presents in middle age.
Additional findings from the analysis show that OMD, a movement disorder associated with abnormal movements in the masticatory, lingual, perioral, and platysma muscles, often has an idiopathic etiology, and jaw-opening oromandibular dystonia (JOOD) appears to be the most predominant clinical type of the focal dystonia compared with jaw-closing oromandibular dystonia (JCOD) and mixed OMD.
Researchers enrolled a total of 244 patients with OMD who were referred to a hospital in Paris, France between 1989 and 2015. All patients were categorized as having JOOD (n=149), JCOD (n=48), or mixed OMD (n=43).
Study investigators retrospectively reviewed patient data to determine demographic and clinical patterns associated with the disorder. Specifically, researchers collected and analyzed data on age of onset, sex, family history of dystonia, and the presence of associated anatomic sites with dystonia (eg, blepharospasm, cervical dystonia, limb dystonia, and spasmodic dysphonia).
On average, age at OMD onset was 51.6 (range, 3.0 to 85.5; SD, 18.6 years), and the predominance of OMD was higher in females vs males by a factor of 2:1 (68.8% vs 31.2%, respectively). In addition, JOOD was present in a slightly greater majority (62.1%), followed by JCOD (20.0%) and mixed OMD (17.9%). Speech was the most affected faculty (63.8%), followed by mastication (49.2%), and swallowing (27.1%).
According to a comparative analysis, pain was significantly more common in JCOD vs mixed OMD and JOOD (71% vs 40% and 18%, respectively, P <.001). In addition, JCOD and mixed OMD were associated with higher rates of dental impairment compared with JOOD (35% and 37% vs 5%, respectively, P <.001). Finally, researchers found that idiopathic OMD was the most common etiology in this sample (71.3%).
Limitations of this analysis include its retrospective design as well as its relatively small sample size.
The study investigators note that the impact of JCOD and mixed OMD on dental impairment “may be due to the hyperactivity of masticatory muscles leading to jaw tension, dental contacts, pain, and other dental effects.”
Slaim L, Cohen M, Klap P, et al. Oromandibular dystonia: demographics and clinical data from 240 patients. J Mov Disord. 2018;11(2):78-81.