ORIGINAL ARTICLE

Oromandibular Dystonia: Demographics and
Clinical Data from 240 Patients

Linda Slaim,<fnref n="1" /> Myriam Cohen,<fnref n="1" /> Patrick Klap,<fnref n="1" /> Marie Vidailhet,<fnref n="2" />

Alain Perrin,<fnref n="1" /> Daniel Brasnu,<fnref n="1" />,<fnref n="3" /> Denis Ayache,<fnref n="1" /> Marie Mailly<fnref n="1" />

ABSTRACT

**Objective** To report demographic data from a large cohort of patients with oromandibular dystonia (OMD).

**Methods** This is a retrospective review of patients with OMD referred to our institution between 1989 and 2015. Demographic (age of onset, gender, and familial history of dystonia) and clinical (type of OMD, associated dystonia, and etiology of dystonia) data were collected from a cohort of 240 individuals.

**Results** The mean age of onset of OMD was 51.6 years old, with a female predominance (2:1). A family history of dystonia was found in 6 patients (2.5%). One hundred and forty-nine patients (62.1%) had the jaw-opening type of OMD, 48 patients (20.0%) had the jaw-closing type, and 43 patients (17.9%) had a mixed form of OMD. Lingual dystonia was also present in 64 (26.7%) of these patients. Eighty-two patients (34.2%) had a focal dystonia, 131 patients (54.6%) had a segmental dystonia, and 27 patients (11.3%) had a generalized dystonia. One hundred and seventy-one patients (71.3%) had idiopathic OMD.

**Conclusion** OMD is a chronic and disabling focal dystonia. Our study found a prevalence of female patients, an onset in middle age and a predominantly idiopathic etiology. Unlike other studies, jaw-opening was found to be the most frequent clinical type of OMD.

**Key Words** Oromandibular dystonia; focal dystonia; movement disorders.

"Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures, or both. Dystonic movements are typically patterned, twisting, and may be tremulous. Dystonia is often initiated or worsened by voluntary action and associated with overflow muscle activation." Dystonia is classified along two axes: clinical characteristics and etiology.<fnref n="1" />

Oromandibular dystonia (OMD) involves the masticatory, lingual, perioral, and platysma muscles. The estimated annual incidence is 3.3 to 6.9 cases per 1 million people.<fnref n="2" />,<fnref n="3" /> The different clinical forms encountered are jaw-opening oromandibular

dystonia (JOOD), jaw-closing oromandibular dystonia (JCOD), and mixed OMD (patients with two or more combinations of either JCOD, JOOD, or jaw deviation (JD), and with no clinical predominance of any subtype⁴). OMD is a chronic condition affecting speech and swallowing, leading to an impaired quality of life. OMD can either be a primary disease or secondary to other disorders. Patients are categorized as having focal, segmental, multifocal, or generalized dystonia. OMD can be focal, but more often is part of a segmental or general dystonia.⁵ The average age of symptom onset is between 50 and 60 years old, and most studies report a female predominance.⁵⁻⁸ The

<footnote n="1">¹Department of ENT and Head and Neck Surgery, Fondation Adolphe de Rothschild, Paris, France</footnote>

<footnote n="2">²Department of Neurology, Hôpital de la Pitié Salpétrière, Assistance Publique-Hôpitaux de Paris, Paris, France</footnote>

<footnote n="3">³Université Paris Descartes Sorbonne, Paris Cité, France</footnote>
purpose of this study was to analyze the demographic and clinical data of patients with OMD referred to our institution over a 25-year period and to compare our results to other studies published in the literature.

## MATERIALS & METHODS

A retrospective analysis of patients with OMD referred to Fondation Ophtalmologique Adolphe de Rothschild (Paris, France) from 1989 to 2015 was conducted after approval of the affiliated ethical committee (CE_20150630_7_LSM). Clinical evaluation included a fiberoptic transnasal laryngoscopy with a swallowing test. All patients were evaluated by the same otolaryngologist and neurophysiologist. Patients underwent complete neurological testing, including brain imaging. Patients were rated as having JOOD, JCOD, or mixed OMD, with or without lingual involvement. Data concerning gender, age of onset, family history of dystonia, presence of associated anatomic sites with dystonia (blepharospasm, cervical dystonia, spasmodic dysphonia, or limb dystonia) were collected. The etiology of dystonia (idiopathic, tardive, neurodegenerative, post-anoxic, or post-traumatic) was recorded. Dystonia was defined as idiopathic when etiology was not determined.¹ Clinical symptoms such as impairment of speech, mastication or swallowing, pain, and dental effects were also recorded.

Electromyography was used for accurate identification of the muscles involved with the exception of the platysma and perioral muscles.

Statistical analysis was performed using R-software,⁹ Fisher's exact test, and the Kruskal-Wallis test. The criterion for statistical significance was set at *p* < 0.05.

## RESULTS

Two hundred and forty-four patients with OMD were referred to our institution between 1989 and 2015. Four patients who had initial assessment and treatment performed at another center were excluded. A total of 240 patients were included in our study (Table 1).

The mean age of onset was 51.6 years old (range, 3.0–85.5 years; SD = 18.6 years). The majority of patients were referred to us by neurologists (82%).

<table><caption>**Table 1.** Demographics and clinical characteristics</caption><thead><tr><th>Characteristics</th><th>OMD (n = 240)</th></tr></thead><tbody><tr><td>Females, n (%)</td><td>165 (68.8)</td></tr><tr><td>Males, n (%)</td><td>75 (31.2)</td></tr><tr><td>Mean age of onset, y (range, ± SD)</td><td>51.6 (3.0–85.5, ± 18.6)</td></tr><tr><td>OMD type, n (%)</td><td></td></tr><tr><td>JOOD</td><td>149 (62.1)</td></tr><tr><td>JCOD</td><td>48 (20.0)</td></tr><tr><td>Mixed OMD</td><td>43 (17.9)</td></tr><tr><td>Lingual dystonia, n (%)</td><td>64 (26.7)</td></tr><tr><td>Etiology, n (%)</td><td></td></tr><tr><td>Idiopathic</td><td>171 (71.3)</td></tr><tr><td>Tardive</td><td>31 (12.9)</td></tr><tr><td>Neurodegenerative</td><td>18 (7.5)</td></tr><tr><td>Post-anoxic</td><td>16 (6.7)</td></tr><tr><td>Post-traumatic</td><td>4 (1.6)</td></tr><tr><td>Associated movement disorders, n (%)</td><td></td></tr><tr><td>Blepharospasm</td><td>93 (38.8)</td></tr><tr><td>Cervical dystonia</td><td>64 (26.7)</td></tr><tr><td>Spasmodic dysphonia</td><td>49 (20.4)</td></tr><tr><td>Limb dystonia</td><td>14 (5.8)</td></tr><tr><td>Generalized dystonia</td><td>27 (11.3)</td></tr><tr><td>Symptoms, n (%)</td><td></td></tr><tr><td>Speech impairment</td><td>153 (63.8)</td></tr><tr><td>Mastication impairment</td><td>118 (49.2)</td></tr><tr><td>Swallowing impairment</td><td>65 (27.1)</td></tr><tr><td>Pain</td><td>78 (32.5)</td></tr><tr><td>Dental impairment</td><td>40 (16.7)</td></tr><tr><td>Family history of dystonia, n (%)</td><td>6 (2.5)</td></tr></tbody></table>

JOOD: jaw-opening oromandibular dystonia, JCOD: jaw-closing oromandibular dystonia, OMD: oromandibular dystonia.

There was a significant female preponderance—165 of 240 (68.8%) patients were women.

A total of 149 out of 240 (62.1%) patients had JOOD, 48 (20.0%) patients had JCOD, and 43 (17.9%) had mixed OMD. There was no significant difference between these groups in gender or age of onset. Lingual dystonia was present in 64 (26.7%) patients and was significantly more associated with JOOD and mixed OMD than with JCOD (32%, 26%, and 10%, respectively).

Eighty-two of 240 (34.2%) patients had a focal dystonia; 131 (54.6%) patients had a segmental dystonia; and 27 (11.3%) patients had a generalized form of OMD. Segmental dystonia categories included blepharospasm as part of Meige syndrome (93/240, 38.8%), cervical dystonia (64/240, 26.7%), spasmodic dysphonia (49/240, 20.4%), and limb dystonia (14/240, 5.8%). There was no correlation between OMD groups and focal versus segmental/generalized presentation.

Dystonic movements impaired speech in 153
(63.8%) patients, mastication in 118 (49.2%) patients, and swallowing in 65 (27.1%) patients. The movements caused pain in 78 (32.5%) patients and dental impairment (wear or early loss of teeth) in 40 (16.7%) patients. Mastication disorders were less present in JCOD than in JOOD and mixed OMD (25%, 56%, and 58%, respectively). Speech impairment was also less frequent in JCOD than in JOOD and mixed OMD (52%, 70%, and 63%, respectively, *p* < 0.05). There was no significant difference in swallowing impairment between these groups. Pain was common in JCOD, less present in mixed OMD and rare in JOOD (71%, 40%, and 18%, respectively, *p* < 0.001). Dental impairment was mostly present in JCOD or mixed OMD and almost absent in JOOD (35%, 37%, and 5%, respectively, *p* < 0.001).

Most patients (171/240, 71.3%) had idiopathic OMD. Thirty-one (12.9%) patients had tardive dystonia, 18 (7.5%) patients suffered from neurodegenerative disease (Parkinson disease *n* = 9, pantothenate kinase-associated neurodegeneration *n* = 3, GM1 gangliosidosis *n* = 1), 16 (6.7%) patients had a post-anoxic form, and 4 (1.6%) patients presented as post-traumatic OMD. Distribution of dystonia varied depending on etiology (*p* < 0.001). Idiopathic forms were either segmental (63%), focal (29%), or generalized (8%). Tardive dystonia patients were either focal (52%) or segmental (48%) but never generalized. Post-anoxic forms were often generalized (56%). A family history of dystonia was present in 6 patients (2.5%). Five of these patients suffered from an idiopathic focal or segmental dystonia, and one suffered from a generalized dystonia due to a familial mitochondriopathy.

DISCUSSION

Two hundred and forty patients diagnosed with OMD were evaluated over a 25-year period at our institution. To our knowledge, this study is the largest reported in the literature. A comparison of our demographic data with other studies is presented in Table 2.

Our results are similar to the data published by others in terms of gender ratio and age of onset.⁵⁻⁸ The female prevalence has no pathophysiologic explanation.

Focal OMD is rare. OMD is more common as part of a spectrum of cranio-facial segmental or generalized dystonia.⁵,⁹,¹⁰ In our study, 34.2% of patients had focal OMD whereas 54.6% had segmental dystonia and 11.3% presented with generalized dystonia. Sinclair et al.¹¹ reported similar findings with 12 of 59 (34.3%) patients having a focal OMD and 65.7% of patients presenting with a segmental or generalized form. In our study, the segmental form included blepharospasm (Meige syndrome) in 38.8% of patients, cervical dystonia in 26.7%, spasmodic dysphonia in 20.4%, and limb dystonia in 5.8%. Tan and Jankovic⁴ also found blepharospasm (50.0%) and cervical dystonia (57.4%) as more frequently associated movement disorders.

In our study, JOOD was the most frequent form of OMD, 62.1% of patients had JOOD, 20.0% had JCOD, and 17.9% had mixed OMD, as opposed to other studies reported in the literature. Sinclair et al.¹¹ reported 47.4% of patients with JCOD, 35.6% with JOOD, and 16.9% with isolated lateral JD. Tan and Jankovic⁴ reported 52.5% of patients with JCOD, 21.6% with JOOD, 1.9% with isolated lateral JD, and 24.0% with mixed OMD. This difference may

<table><caption>**Table 2.** Comparison of demographics with previously published studies</caption><thead><tr><th>Clinical data</th><th>Sinclair et al.<sup>11</sup></th><th>Tan and Jankovic<sup>4</sup></th><th>Present study</th></tr></thead><tbody><tr><td>n</td><td>59</td><td>162</td><td>240</td></tr><tr><td>Female, n (%)</td><td>40 (67.8)</td><td>111 (68.5)</td><td>165 (68.8)</td></tr><tr><td>Age of onset, mean (SD)</td><td>56.6 (14.0)</td><td>57.9 (15.3)</td><td>51.6 (18.6)</td></tr><tr><td>JOOD, n (%)</td><td>21 (35.6)</td><td>35 (21.6)</td><td>149 (62.1)</td></tr><tr><td>JCOD, n (%)</td><td>28 (47.4)</td><td>85 (52.5)</td><td>48 (20.0)</td></tr><tr><td>Mixed OMD, n (%)</td><td>0</td><td>39 (24.0)</td><td>43 (17.9)</td></tr><tr><td></td><td>JD: 10 (16.9)</td><td>JD: 3 (1.9)</td><td></td></tr><tr><td>Lingual dystonia, n (%)</td><td>10 (16.9)</td><td>-</td><td>64 (26.7)</td></tr><tr><td>Idiopathic OMD, n (%)</td><td>54 (91.5)</td><td>102 (63.0)</td><td>171 (71.3)</td></tr><tr><td>Other movement disorder, n (%)</td><td>23 (65.7)</td><td>-</td><td>158 (65.8)</td></tr><tr><td>Family history, n (%)</td><td>-</td><td>10 (6.2)</td><td>6 (2.5)</td></tr></tbody></table>

JOOD: jaw-opening oromandibular dystonia, JCOD: jaw-closing oromandibular dystonia, OMD: oromandibular dystonia, JD: jaw deviation.
be explained by a bias in the recruitment of our pa-
tients whom were mostly referred to us by neurolo-
gists (82%) who typically referred JOOD and mixed
OMD patients.

Lingual dystonia was present in 26.7% of our co-
hort and was significantly more associated with
JOOD and mixed OMD than with JCOD. There was
no correlation between OMD groups and gender,
age at diagnosis, or focal versus segmental/general-
ized presentation. These results are similar to those
of Sinclair et al.¹¹

Chewing, swallowing, and speech are frequently
impaired in OMD, altering quality of life and social
relationships.¹² In our cohort, 63.8% of patients had
speech impairment, and 49.2% had mastication dis-
orders. Dystonic movements caused pain in 32.5%
of patients and dental troubles in 16.7%. Sinclair et
al.¹¹ described similar results with speech and eat-
ing impairment in 54.3% of patients, pain in 34.3%
and dental effects in 20.0%. Unlike Sinclair et al.,¹¹
we found a correlation between predominant symp-
toms and OMD type. Mastication and speech im-
pairments were less present in JCOD than in JOOD
or mixed OMD. On the other hand, pain and dental
troubles were more common in JCOD and mixed
OMD. Dental effects were mostly present in JCOD
and mixed OMD and rare in JOOD (35%, 37%, and
5%, respectively). This finding may be due to the
hyperactivity of masticatory muscles leading to jaw
tension, dental contacts, pain, and other dental ef-
fects.

Most patients in our cohort (71.3%) presented as
idiopathic OMD. The most frequent secondary form
was tardive dystonia (12.9%). Tan and Jankovic⁴ ob-
served similar results with 63.0% of patients having
idiopathic OMD and 22.8% presenting as tardive
type.

Conclusion

OMD is a chronic and disabling focal dystonia.

Our study shows a prevalence of female patients,
an onset of symptoms between 50 and 60 years of
age, and an idiopathic etiology in the majority of pa-
tients. JOOD was the most frequent type of OMD,
as opposed to other reports.

Conflicts of Interest

The authors have no financial conflicts of interest.

REFERENCES

1. Albanese A, Bhatia K, Bressman SB, Delong MR, Fahn S, Fung VS, et al. Phenomenology and classification of dystonia: a consensus update. Mov Disord 2013;28:863-873.

2. Merz RI, Deakin J, Hawthorne MR. Oromandibular dystonia questionnaire (OMDQ-25): a valid and reliable instrument for measuring health-related quality of life. Clin Otolaryngol 2010;35:390-396.

3. Balasubramaniam R, Rasmussen J, Carlson LW, Van Sickels JE, Okeson JP. Oromandibular dystonia revisited: a review and a unique case. J Oral Maxillofac Surg 2008;66:379-386.

4. Tan EK, Jankovic J. Botulinum toxin A in patients with oromandibular dystonia: long-term follow-up. Neurology 1999; 53:2102-2107.

5. Lee KH. Oromandibular dystonia. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:491-496.

6. Marsden CD. Blepharospasm-oromandibular dystonia syndrome (Brueghel's syndrome). A variant of adult-onset torsion dystonia? J Neurol Neurosurg Psychiatry 1976;39: 1204-1209.

7. Epidemiological Study of Dystonia in Europe (ESDE) Col-
laborative Group. A prevalence study of primary dystonia
in eight European countries. J Neurol 2000;247:787-792.

8. Blanchet PJ, Rompré PH, Lavigne GJ, Lamarche C. Oral dyskinesia: a clinical overview. Int J Prosthodont 2005;18: 10-19.

9. Singer C, Papapetropoulos S. A comparison of jaw-closing and jaw-opening idiopathic oromandibular dystonia. Parkinsonism Relat Disord 2006;12:115-118.

10. Scott BL. Evaluation and treatment of dystonia. South Med J 2000;93:746-751.

11. Sinclair CF, Gurey LE, Blitzer A. Oromandibular dystonia: long-term management with botulinum toxin. Laryngoscope 2013;123:3078-3083.

12. Papapetropoulos S, Singer C. Eating dysfunction associat-
ed with oromandibular dystonia: clinical characteristics
and treatment considerations. Head Face Med 2006;2:47.