Torgny Haraldson

Functional state, bite force and postural muscle activity in patients with osseointegrated oral implant bridges

The function of the masticatory system of 13 women, aged 42-59 years, with osseointegrated oral implant bridges (OIB) made within the last seven years was compared with that of 10 matched dentate controls by means of a questionnaire, clinical examination, bite force measurements and electromyographic recordings of biting and of postural muscle activity. Both groups were satisfied with their masticatory capacity according to the questionnaire. The clinically determined state of the masticatory system, as judged from the clinical dysfunction index, was normal in both groups. Three levels of bite force 1) gentle biting, 2) biting as when chewing and 3) maximal biting, were recorded with a bite force apparatus and electromyographically. There was no statistically significant difference between the groups at any level of bite force for any of the methods of registration. Nor was there any difference of the two groups in the activity of the masticatory muscles with the mandible in the postural position. It is concluded that patients with osseointegrated oral implant bridges have a masticatory muscle function equal to or approaching that of patients with natural teeth, or with tooth-supported bridges, with the same number of chewing units as the OIB-patients.

Acupuncture in treatment of facial muscular pain

Forty-five individuals with long-standing facial pain or headache of muscular origin were randomly allocated into three groups. The first group was treated with acupuncture, the second group received an occlusal splint, and the third group served as controls. Both acupuncture and occlusal splint therapy significantly reduced subjective symptoms and clinical signs from the stomatognathic system. No differences between these two groups were found with regard to treatment effects. It is concluded that acupuncture is an alternative method to conventional stomatognathic treatment for individuals with craniomandibular disorders of muscular origin.

Long-term effect of intra-articular injections of sodium hyaluronate and corticosteriod on temporomandibular joint arthritis☆

The long-term effect of intra-articular injections of sodium hyaluronate and corticosteroid (betamethasone) was compared in a sample of 24 patients who had pain and tenderness to palpation in the temporomandibular joint (TMJ arthritis) of at least six months duration, and who had not responded to conservative treatment. The two drugs were randomly allocated to the patients. The drugs, 0.5 ml, were injected twice into the superior joint compartment of the TMJ with a two-week interval between injections. The effect on subjective symptoms, clinical signs, and bite force was assessed. At the one and two-year follow-ups both the hyaluronate-and the corticosteroid-group had significantly reduced subjective symptoms as well as clinical signs, and the maximum voluntary bite force was significantly increased. The differences in effect between treatments were not statistically significant. It was concluded that both drugs have a significant long-term effect on chronic arthritis of the TMJ and that either of the drugs can be helpful; however, sodium hyaluronate might be the best alternative due to the least risk for side effects.

Bite plates and stabilization splints in mandibular dysfunction: A clinical and electromyographic comparison

Twenty patients with mandibular dysfunction, all women, aged 17-41 years, were randomized for treatment with either a bite plate with a frontal plateau or a full-coverage stabilization splint. The occlusal appliances were used at night for 6 weeks to compare clinical and electromyographic effects (EMGs). Integrated EMGs were recorded bilaterally from the anterior and posterior parts of the temporal muscle and the masseter muscle in the rest position and during gentle and maximal biting before and after treatment without the appliances in situ. Initially recorded EMG activity in the temporal muscle was correlated to signs of dysfunction in the rest position. Compared with previously investigated healthy subjects, the patients had lower EMG activity in the anterior part of the temporal muscle and in the masseter muscle during maximal biting. Use of occlusal appliances at night for 6 weeks did not change the EMG activity in the rest position or during maximal biting. The clinical signs improved, significantly in the splint group. The subjective symptoms improved in both groups, significantly more in the splint group.

Comparisons of chewing patterns in patients with bridges supported on osseointegrated implants and subjects with natural dentitions

The masticatory muscle activity during chewing was studied by means of electromyography (EMG) in 13 women treated with bridges supported on osseointegrated implants and compared with that in 10 dentate control subjects. The factors studied were the changes of the maximal mean voltage amplitude and the duration and coordination of activity during chewing of peanuts, bread, and apple when comparing the first three with the last three out of ten randomly selected chewing cycles. Patients with implant-supported bridges chewed with approximately the same muscle activity during the whole chewing sequence, whereas the control subjects had a reduced activity at the end of the chewing act.

Muscle function during chewing and swallowing in patients with osseointegrated oral implant bridges. An electromyographic study.

The activity of the anterior and posterior portions of the temporal muscle, the masseter and the upper lip has been studied with electromyography in 13 women with osseointegrated oral implant bridges and compared with that in 10 subjects with natural teeth. The functions examined were chewing and swallowing of apple, bread and peanuts. There was no difference between implant and control subjects in the number of chewing cycles nor in duration of the act of chewing or in the amplitude of the muscle activity during chewing and swallowing. However, the duration of the activity during chewing was longer in the implant than in the control subjects. The number of years of wearing a maxillary implant bridge was found to be of importance for the number of chewing cycles during an act of chewing and for the muscle activity during chewing. Other factors influencing the muscle activity were age, number of occluding tooth units and the extension of the lower implant bridge. It was concluded that patients with osseointegrated oral implant bridges have a masticatory muscle function equal to or approaching that in patients with natural teeth or with bridges supported on natural teeth with the same extension of the dentition.

Reproducibility and variation of skin surface temperature over the temporomandibular joint and masseter muscle in normal individuals

Temperature, temperature differences between right and left sides, temperature variation with time, and temperature measurement reproducibility were investigated in 42 normal individuals over the origin of the superficial portion of the masseter muscle and the temporomandibular joint (TMJ) with fast- and slow-reacting thermistors. The average temperature was higher with the fast-reacting thermistor than with the slow-reacting thermistor for all measured locations. The temperature difference between the left and right side was in about 90% of the performed measurements less than or equal to 1 degree C in both locations. The temperature also differed between the two locations and was highest at the skin surface over the TMJ. The reproducibility of the method according to the standard deviation of a single measurement was satisfactory.

Mandibular dysfunction and periodontitis. A comparative study of patients with periodontal disease and occlusal parafunctions.

Fifty-one patients (mean age, 47.3 years) with moderate to severe periodontal disease and 40 patients (mean age, 48.9 years) with symptoms related to bruxism (occlusal parafunctions such as grinding and/or clenching of the teeth) were compared with regard to periodontal conditions and signs and symptoms of mandibular dysfunction. The bruxists reported more symptoms of pain and dysfunction of the masticatory system than the periodontal patients. The clinical dysfunction index was significantly higher among the bruxists, while there was a similarity between the groups in the variation of occlusal conditions, except for occlusal wear, which was more pronounced in the bruxist group. Attrition was in general positively correlated to alveolar bone height. This correlation was stronger (and statistically significant) for the canines than for other teeth. Attrition was negatively correlated to tooth mobility. It is concluded that patients with moderate to severe periodontal disease and patients with bruxism/occlusal parafunctions are distinctly different with regard to signs and symptoms of mandibular dysfunction. The results support the opinions that there is no or only weak correlation between periodontal disease and bruxism, and between bruxism and occlusal status.

Three-year longitudinal study of mandibular dysfunction in young adults with intact and restored dentitions

Thirteen adolescents with intact dentitions and 16 with restored dentitions were re-examined after 3 years for signs and symptoms of mandibular dysfunction. In accordance with the results of the first examination, a lower prevalence and degree of clinically recorded dysfunction was found at the follow-up study in subjects with intact teeth than in those with dental restorations. This difference was especially explained by more muscle tenderness recorded in the individuals with restored dentitions than in those with intact teeth. However, the reported symptoms were as a rule mild and relatively evenly distributed in the two groups.