Prevalence and clinical characteristics of patients with oromandibular dystonia seen in the orofacial pain clinic: a retrospective study

Surface electromyography for evaluating patients with oromandibular dystonia

OBJECTIVE

To investigate myoelectric signals of dystonic activities in oromandibular dystonia (OMD) subjects using surface electromyography (EMG).

METHODS

Twelve OMD subjects were included in this study. Resting myoelectric activities of the superficial masseter, anterior temporalis, and anterior belly of the digastric muscle on both sides were monitored, and dystonic muscle contractions were recorded using surface EMG. Myoelectric signal amplitude, the type of muscle contraction, and contraction rate for phasic activities were evaluated.

RESULTS

Surface EMG revealed that eight subjects had dystonic muscle activities in the phasic contraction pattern, three subjects had a tonic contraction pattern, and one subject had a mixed pattern. Synchronous contraction of dystonic muscles was frequently observed. Many of the monitored muscles showed high resting amplitudes.

CONCLUSION

Surface EMG detects abnormal muscle activities related to oromandibular dystonia. Surface EMG can serve as an objective method for diagnosing oromandibular dystonia.

The prevalence of idiopathic or inherited isolated dystonia: a systematic review and meta‐analysis

Background

A systematic review of epidemiological studies of primary dystonia from 1985 and 2010 found an overall prevalence of 16.43 per 100,000 (95% CI = 12.09–22.32).

Methods

We performed a systematic review of studies from 2010 and 2022 to determine if there are important differences in epidemiology between these time periods.

Results

Nineteen studies were included. Incidence of cervical dystonia, blepharospasm, and oromandibular dystonia were each reported in one study; one study reported incidence for all adult onset idiopathic focal dystonias combined. Using data from 11 studies, we performed random effects meta‐analyses of the prevalence of cervical dystonia (9.95 per 100,000; 95% CI = 3.51–28.17), blepharospasm (2.82 per 100,000; 95% CI = 1.12–7.12), laryngeal dystonia (0.40 per 100,000; 95% CI = 0.09–1.83), upper limb dystonia (1.27 per 100,000; 95% CI = 0.36–4.52), oromandibular dystonia (0.57 per 100,000; 95% CI = 0.15–2.15), and idiopathic or inherited isolated dystonia all subtypes combined (30.85 per 100,000; 95% CI = 5.06–187.74). All studies reported more cases of dystonia in females. There was no significant difference in prevalence by subgroup analysis based on time of study publication (1985–2010 vs. 2010–2022). Subgroup analysis of differences in prevalence by dystonia subtype by continent using all studies published (1985–2022) revealed significant regional differences in the prevalence of cervical and laryngeal dystonia.

Conclusion

The incidence and prevalence of idiopathic or inherited isolated dystonia in the last decade was not significantly different from earlier reports. Population‐based studies across multiple geographic areas are needed to obtain a clearer understanding of the epidemiology of this condition.

Oromandibular dystonia and temporomandibular disorders

BACKGROUND

The aim of this study was to characterize clinical features of patients with oromandibular dystonia (OMD) who had temporomandibular disorder (TMD) symptoms.

METHODS

A retrospective chart review of patients seeking treatment at a tertiary-level orofacial pain clinic from January 2015 through December 2020 was undertaken. The inclusionary criteria consisted of a diagnosis of OMD (International Classification of Diseases, Revision 10 code G24.4), which had been confirmed by a neurologist.

RESULTS

Eleven patients met the inclusion criteria. Focal dystonia and jaw deviation OMD were the most frequent diagnoses. A dental procedure was a triggering or aggravating factor in 36.4% of patients. All but 2 patients had a sensory trick, or tactile stimulus to a particular body part, and approximately one-half of the patients used an oral appliance as a sensory trick device. All but 1 patient had received a diagnosis of TMD, with myofascial pain of the masticatory muscles being the most prevalent diagnosis. Four patients had received a recommendation for orthodontic treatment. About one-half of the patients had undergone 1 or more invasive dental or maxillofacial surgical interventions to address their dystonia. Anxiety was the most common psychological comorbidity.

CONCLUSIONS

Because patients with OMD commonly experience TMD symptoms, they can receive a misdiagnosis of TMD while the OMD is overlooked.

PRACTICAL IMPLICATIONS

Owing to concomitant TMD symptoms, patients most often seek dental consultations and undergo treatments such as orthodontic interventions and temporomandibular joint surgeries. A dentist's competency in recognizing these patients can prevent unnecessary procedures and facilitate appropriate patient care.

Oral health and oral health-related quality of life in patients with oral dystonia indicates their need for dental special care

BACKGROUND

This retrospective study aimed in the evaluation of oral health and oral health-related quality of life (OHRQoL) of patients with oral dystonia (OD).

MATERIAL AND METHODS

Seventeen patients with OD (Meige Syndrome: n=11, Oromandibular Dystonia: n=6) were included, of which seven were examined again at three months after botulinum toxin injection. OHRQoL was assessed by the German short form of oral health impact profile (OHIP G14). Within oral examination, dental parameters, remaining teeth and periodontitis severity were assessed. A matched healthy control (HC) was composed for comparison.

RESULTS

The OD patients had significantly more carious teeth (0.94 ± 1.75 vs. 0; p<0.01), less remaining teeth (15.65 ± 9.89 vs. 22.22 ± 5.91; p=0.01) and higher dental treatment need than the HC (42.9% vs. 0%; p<0.01). The OHIP G14 sum score of 9.47± 9.82 vs. 1.58 ± 2.79 (p<0.01) as well its dimensions psychosocial impact (4.47 ± 6.45 vs. 0.53 ± 1.16; p=0.03) and oral function (4.35 ± 2.98 vs. 0.47 ± 1.34; p<0.01) were clinically relevant and statistically significant higher in OD compared to HC group. No significant differences could be detected at three months after botulinum toxin injection.

CONCLUSIONS

Patients with OD suffer from more dental diseases and have a worse OHRQoL than HC. Dental special care appears recommendable and should be fostered by everyone, who is involved in the treatment of patients with OD.

Prevalence and incidence of oromandibular dystonia: an oral and maxillofacial surgery service-based study

OBJECTIVES

Oromandibular dystonia is a focal dystonia characterized by sustained or intermittent contractions of the masticatory and/or tongue muscles. This epidemiological study aimed to estimate the prevalence and incidence of oromandibular dystonia in Kyoto (population: 1,465,701).

MATERIALS AND METHODS

The population sample was citizens of Kyoto who visited our department between 2015 and 2019 and were differentially diagnosed by an oromandibular dystonia specialist having idiopathic (primary) and acquired (secondary) oromandibular dystonia. A total of 144 patients (100 women and 44 men; mean age, 57.5 years) were analyzed for clinical features, and the prevalence (prevalence date, January 1, 2020) and annual incidence were estimated.

RESULTS

The male-to-female ratio was 1:2.3 (p<0.001). Age at onset was significantly (p<0.01) earlier in men (47.5 years) than that in women (56.9 years). The crude prevalence of oromandibular dystonia was estimated at 9.8 per 100,000 persons (95% confidence interval: 8.3-11.6) (idiopathic dystonia, 5.7 [4.6-7.1]; tardive dystonia, 3.4 [2.5-4.5]) and incidence at 2.0 (1.3-2.8) per 100,000 person-years (idiopathic dystonia, 1.2 [0.68-1.9], tardive dystonia, 0.68 [0.32-1.3]). The prevalence was 13.0 (10.5-15.8) in women and 6.3 (4.6-8.5) in men. All age groups showed female predominance. The highest prevalence was 23.6 (14.4-36.5) in women aged 60-69 years.

CONCLUSIONS

As this is an oral and maxillofacial surgery service-based study, the actual prevalence of oromandibular dystonia may be even higher.

CLINICAL RELEVANCE

It was suggested that oromandibular dystonia might be more common than cervical dystonia or blepharospasm.

Temporomandibular disorder-related characteristics and treatment outcomes in Oromandibular Dystonia patients in two different clinical settings: A cross-sectional study

INTRODUCTION

Clinical presentation of oromandibular dystonia (OMD) is variable that can be further complicated by the presence of temporomandibular disorder (TMD) symptoms. We sought to evaluate variations in the clinical presentation of OMD patients, particularly TMD-related characteristics, in two clinical settings.

METHODS

In a cross-sectional study design, a Web-based data collection survey was provided to eligible patients with OMD from movement disorder (MD) and oro-facial pain (OFP) clinics. The survey questionnaire was designed to collect information on demographic characteristics, clinical presentation particularly related to TMD, quality of life and treatment outcomes. Validated questionnaires were used when available such as the TMD Pain Screener, EuroQol 5-Dimensions 5-Levels (EQ-5D-5L), Jaw Functional Limitation Scale and Global Rating of Change Scale.

RESULTS

Of 53 eligible patients, 31 responded to the survey for a 58% response rate. Forty-eight per cent of patients in the MD clinic and 60% of patients in the OFP clinic reported jaw pain along with involuntary movements. Of those, 90% from the MD group and 83% from the OFP group screened positive with the TMD Pain Screener at the onset of symptoms based on recall. Positive TMD Pain Screener response was observed in about 40% of patients in both clinics within 30 days of questionnaire response. No statistically significant differences were observed between two groups for any measured variables.

CONCLUSION

Patients with OMD have features of TMD, irrespective of the clinical setting in which they seek and receive care. OMD patients from both clinics were similar in terms of clinical presentation, quality of life and treatment outcomes.