Masticatory muscle activity in myotonic dystrophy patients

summary The aim of the study was to compare the masticatory pattern and the activity of the masticatory muscles of a group of myotonic dystrophy patients with those of a group of healthy individuals. The electromyographic (EMG) activity of the temporal and the masseter muscles was measured in the resting position, during maximal clenching, and while the patient was chewing five peanuts until swallowing. It was found that the patients had approximately 3 times less EMG activity in the masticatory muscles during maximal clenching. During chewing the patients had approximately half the activity in the anterior temporal and the masseter muscles, while the activity of the posterior temporal muscle did not differ significantly from that in healthy individuals. No differences were found in the muscle activity in the resting position or in the speed of chewing between the groups. The patients needed more time and more chewing cycles to bring the five peanuts to the swallowing threshold, but possibly this was an effect of the lower number of antagonizing teeth. Myotonic dystrophy thus influences the masticatory muscles, reducing their activity both at a maximal and a functional level.     

Dental characteristics of patients with Duchenne muscular dystrophy

A comprehensive assessment of the dental characteristics of 23 patients with Duchenne muscular dystrophy (DMD) was carried out, based on dental records, oral examinations and dental models. Decreasing muscle function was associated with increased plaque and calculus accumulation, leading to gingival inflammation, but caries experience was low. Disturbances in tooth form, number and eruption of the second premolars were observed in 39% of patients. Anterior and posterior open bites were common, associated with lip incompetence, mouth breathing, macroglossia and tongue thrusting. Maxillary and mandibular arch breadths were significantly larger, on average, in the DMD group than in controls. Rather than a normal parabolic arch form, the dental arches in DMD patients tended to be hyperbolic, with the posterior teeth being displaced buccally, consistent with an imbalance between the lingual and facial musculature.     

Temporomandibular dysfunction in adult patients with myotonic dystrophy (DM1)

Myotonic muscle dystrophy is a systemic disease with early engagement of the facial muscles. Our aim was to study dysfunction of the temporomandibular system in patients with ‘classic’ dystrophia myotonica (DM1) and compare it with TMD patients and healthy controls. The study included 27 referred patients with DM1, 18 women and nine men, aged 30–62 years, and two matched control groups: patients with temporomandibular disorders symptoms (TMD) and healthy controls, both groups were consecutive patients. The patients answered questions regarding facial pain, jaw function and dysfunction. A clinical examination of the temporomandibular system including the occlusion was performed, and the maximum bite force and finger forces were measured. Among the DM1 patients, 33% reported difficulty biting off, and 22% had difficulty chewing, avoiding foods like meat and raw vegetables, and 37% of the DM1 patients scored their pain and discomfort as moderate to fairly severe. Their main complaints were TMJ clicking and locking, difficulty opening wide and tiredness. They had more clinical signs of dysfunction compared with the controls (P < 0·001), but no statistically significant difference to the TMD patients. The maximum bite force in DM1 patients was impaired compared to both the TMD patients and the controls (P < 0·001). Significantly more occlusal interferences were found in DM1 patients and were associated with chewing difficulties (P < 0·001). In conclusion, patients suffering from DM1 had an increased prevalence of TMD symptoms, reported impaired chewing function and had a decreased maximum bite force.     

Ultrasound imaging of the masseter muscle in myotonic dystrophy patients

summary Ultrasound technique was applied to measure the thickness and examine the internal structure of the masseter muscle in a group of 16 adult patients (nine women and seven men) with myotonic dystrophy (MyD) and 16 healthy individuals matched in age, sex and number of occluding teeth. The masseter thickness was measured bilaterally under both relaxed conditions and during maximal clenching. The error of measurement was found to be small, not exceeding 0.45 mm. The imaging characteristics of the masseter in most of the MyD patients was an obvious atrophy of the muscle with increased echointensity of the intramuscular tissue and loss of the internal structure concerning tendons and fasciae. The mean masseter thickness (±SD) in the MyD group was 10.4 (±2.2) mm under relaxed conditions and 11.1 (±2.4) mm during maximal clenching, compared with 13.3 (±2.2) mm and 14.1 (±2.4) mm, respectively, in the healthy group (P < 0.001). In conclusion, our results indicate that, in most of the myotonic dystrophy patients, the masseter muscle is atrophic with obvious signs of degeneration. Ultrasound is a useful method for both qualitative and quantitative evaluation of the condition of the masseter muscle.     

Bite force and handgrip force in patients with molecular diagnosis of myotonic dystrophy

Myotonic dystrophy is a multisystemic disease with varying symptomatology. The aim of this study was to compare the maximal bite force and handgrip force in patients with molecular diagnosis of myotonic dystrophy with those in a group of healthy individuals. It was hypothesized that these forces were reduced in the patients in comparison with the control subjects. The bite and handgrip forces of 37 patients with molecular diagnosis of myotonic dystrophy and 37 control subjects matched regarding age and gender were measured using an electronic dynamometer. The bite and handgrip forces were significantly lower in the myotonic dystrophy patient group when compared with the healthy controls (P < 0.0001). There were no significant force differences between genders, right- or left-hand side of mastication or hands in the myotonic dystrophy patient group whereas such differences were found among the controls. There were moderate but significant correlations between bite and handgrip force in both groups (r = 0.43-0.59; P < 0.01). It was concluded that there were considerable differences between the myotonic dystrophy group and the control subjects regarding both bite force and handgrip force. The weakness of the masticatory and hand muscles may have various negative consequences for oral function and dental health in patients with myotonic dystrophy.     

Dental experience and self-perceived dental care needs of patients with angioedema

The purpose of this study was to investigate the self-perceived dental care needs and dental experiences of patients with angioedema. At the 1998 annual meeting of the Voluntary Association for the Fight, Study and Treatment of Hereditary Angioedema (Associazione volontaria per la lotta, lo studio e la terapia dell'angioedema ereditario), a self-administered questionnaire was distributed to participants affected by hereditary or acquired angioedema. Fifty-seven persons completed the questionnaire (37 females, 20 males; mean age, 39 ± 17 yrs; range, 5–76). The vast majority (91%) had the hereditary form of the disease. One-third of the respondents had some problems in obtaining oral treatment, with one person having been refused care. About half of the group had experienced an acute attack following dental treatment. Preventive measures needed improvement in about two-thirds of respondents. More than half (58%) of the group perceived a need for dental care. We conclude that persons with angioedema may experience difficulty in obtaining dental treatment, a common cause of acute attacks.     

Muscle function and craniofacial morphology: a clinical study in patients with myotonic dystrophy

The occlusal traits and the craniofacial morphology were studied in patients with an altered muscle function caused by myotonic dystrophy. Twenty-four adult patients were examined and compared with a matched group of healthy individuals. The condition of the masticatory muscles was evaluated by measuring the maximal bite force. The dental arches and the occlusal traits were analysed on dental casts. Lateral cephalograms were taken in the patients with myotonic dystrophy to study the craniofacial morphology. It was found that the patients suffering from myotonic dystrophy had weak masticatory muscles, which might be caused by the disease. A high prevalence of malocclusions (postnormal occlusion, anterior open bite and lateral cross bite) was found among these patients. Their craniofacial morphology showed a vertical aberration, characterized by a large angle between the mandibular and palatal planes and a steep mandible. These findings seem to be most pronounced in patients with an early onset of the disease and support the hypothesis that reduced muscle function may cause changes in the craniofacial morphology.     

Craniofacial development in myotonic dystrophy.

Anthropometric, cephalometric, and dental data from 23 subjects (12 males and 11 females) afflicted with myotonic dystrophy were compared to similar data from normal subjects who participated in the Iowa Facial Growth Study. A two by two analysis of variance showed that myotonic subjects differed from normal subjects in headlength, head breadth, cephalic index, bizygomatic face width, nosebreadth, maxillary arch widths, palatal depth, anterior and posterior face heights, cranial base lengths, cranial base angles, and other cephalometric measures. Sex differences were observed for many of the variables. It is hoped that these findings will assist clinicians who treat patients having this disorder.     

Oral health in children and adolescents with myotonic dystrophy

Myotonic dystrophy or dystrophia myotonica (DM) is a hereditary neuromuscular multisystem disease with a varying clinical expressivity and severity. The objective of this study was to assess the oral health in children with myotonic dystrophy and to compare it with a control group. Fifty-six DM patients, aged 2.7-18.0 yr, were compared with age- and gender-matched control patients with respect to caries, plaque, and gingivitis. Oral function and signs of temporomandibular dysfunction (TMD) were assessed, and the ability to co-operate in dental treatment was estimated. Questionnaires concerning eating habits, dental care, traumatic injuries to teeth, and orofacial function were also used. The DM patients had significantly more caries, plaque, and gingivitis than did control patients. They had more TMD problems and lower co-operation ability than the healthy control persons. General sedation was frequently needed to carry through dental treatment. DM patients are at risk of caries, gingivitis and TMD problems, and need intensified prophylactic care. Behavior management problems are common.     

Dental treatment needs among hospitalized adult mental patients

This survey determines the dental care needs of hospitalized adults with psychiatric and mental disorders. Comprehensive clinical and radiographic oral examinations, conducted on 33% of the patients in a large state mental hospital, found that extensive unmet needs existed in this population. The major requirements were for prophylaxes, calculus removal, and periodontal therapy. The patients' needs varied depending on several demographic factors, including length of hospitalization and psychiatric diagnoses.