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Biomedical subjects

T Haraldson

Publications and source records attributed to T Haraldson.

At least 55 records · Page 3Linked to original sources
PubMed1985

Relationship between myoelectric activity in masticatory muscles and bite force.

Myoelectric activity in the anterior and posterior temporalis and in the masseter muscle was assessed in five subjects biting unilaterally on a bite fork at 50, 100 and 200 N for 60 s. The bite fork was placed between the right first premolars and the first molars. The ipsilateral muscle activity was recorded first, and the contralateral side was evaluated 1 wk later. The relationship between exerted force and EMG-activity was expressed as ratios between EMG-activity and related bite force. EMG-activity increased with increasing force for all muscles tested. Linearity was found for the anterior temporal muscle, but not for the other muscles. Four of the subjects participated in an endurance test, exerting maximum bite force on the right side for as long as possible. The EMG activity of the right masseter muscle was closely related to bite force, in contrast to the other tested muscles. The activity of the left muscles increased at the end of the endurance test.

Adult↗
PubMed1985

Comparative electromyographic study of bite plates and stabilization splints.

The object was to study any influence on the integrated electromyographic activity in the masseter and temporal muscles of two types of occlusal appliances. Seventeen healthy subjects wore a bite plate with a frontal plateau and a full coverage stabilization splint at night, each for 1 wk. The EMG activity was recorded without appliances in situ, in the rest position, and during gentle and maximum biting before and after the use of the different appliances. After use of the bite plate, the EMG activity was not significantly different at any tested level. After use of the splint, the activity in the rest position was significantly lower in the anterior and posterior parts of the temporal muscles. The EMG activity was significantly lower in the rest position in both parts of the temporal muscle after use of the splint than after use of the bite plate. In a control group of eight subjects in whom no appliances were used, the EMG activity did not change significantly between the initial and 1- or 5-wk recordings. Thus, the occlusal design of the appliances seems to be of importance for the influence on the EMG activity in the masticatory muscles, at least in healthy subjects.

Adult↗
PubMed1985

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.

Adolescent↗
PubMed1985

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.

Adult↗
PubMed1985

Oral galvanism and mandibular dysfunction.

Sixty-two patients were referred to the university dental clinics in Göteborg for examination and treatment of presumed oral galvanism. Thirty of the patients, with an average age of 47 years, were found to suffer from various degrees of mandibular dysfunction. In these 30 patients the most commonly reported symptom was headache, which was present in 67 per cent of the individuals, while mandibular dysfunction was the most common diagnosis. Nineteen patients improved or recovered completely after counselling and/or treatment. Occlusal splints, alone or in combination with other therapeutic methods, were given to 80 per cent of the patients. It is emphasised that patients with putative oral galvanism must be given proper care, including examination of the masticatory system and treatment of diagnosed functional disturbances.

Adult↗
PubMed1985

An oral and psychosocial examination of patients with presumed oral galvanism.

The present investigation was performed to elucidate possible etiological factors behind the complaints reported by 62 patients referred because of presumed oral galvanism. Twenty-nine patients, matched with a subsample of the test group regarding age and sex, comprised a control group. The patients were examined regarding oral medical and stomatognathic health. Their psychological and social health and symptoms were evaluated by means of a standardised interview and 5 self-rating questionnaires. A complex symptomatology including symptoms from both the oral regions and other parts of the body constituated the most distinctive feature of the patients in the test group. The clinical examination as well as patient-perceived symptoms revealed high prevalences of parafunction and dysfunction in the muscles of the stomatognathic system. Furthermore, general complaints were mainly related to muscles of the extremities, and diseases of the joints and muscles were the most commonly reported disorder. The findings at the oral medical examination revealed no differences between the groups, except for signs of parafunction. Patients in the test group gave evidence of being more exposed to negative social events and the results clearly indicate a psychogenic component behind the reported complaints.

Electrogalvanism, Intraoral↗
PubMed1984

Occlusal perception of thickness in patients with bridges on osseointegrated oral implants.

Perception of thickness was estimated in subjects with osseointegrated oral implant bridges (OIB), complete denture wearers and subjects with complete natural dentitions. The test was performed with factory-produced aluminum foil, 9, 20, 50, 100 and 150 micrometers thick, in the regions of the right second premolars, the canines and the central incisors. Occlusal perception did not differ between the three regions in any of the groups. Certain perceptiveness (greater than 80% of tests correct) was found at the 20 micrometers level in subjects with natural dentitions, at the 50 micrometers level in OIB subjects and at the 100 micrometers level in subjects with a complete denture in one or both jaws. It is concluded that partial or complete lack of periodontal receptors is compensated for by other perceptive organs and that implant bridge therapy ad modum Brånemark partly restores occlusal sensibility.

Aged↗
PubMed1983

Normal variation in skin surface temperature over the temporomandibular joint and masseter muscle.

The range of the temperature at the skin surface overlying the temporomandibular joint (TMJ) and the origin of the superficial belly of the masseter muscle was investigated in 35 individuals with normal TM joints and 29 individuals with normal masseter muscles. The temperature was measured by a thermistor in contact with the skin. The temperature over the TMJ varied between 32.1 degrees C and 35.5 degrees C (average 34.3 degrees C). The difference in temperature between right and left sides was to an average 0.3 degrees C. The temperature over the masseter muscle ranged from 30.9 degrees C to 35.7 degrees C (average 33.2 degrees C). The difference in temperature between right and left sides was an average 0.4 degrees C. It was concluded that there is a fairly wide range of skin temperature over the normal TMJ and origin of the masseter muscle under the experimental conditions prevailing in this study but that the differences between right and left sides are fairly small. It therefore seems possible to use this thermometric method to assess inflammatory processes and/or changed metabolic activity in the TMJ and masticatory muscles.

Adolescent↗
PubMed1983

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.

Adult↗
PubMed1982

Temporal arteritis: a report on two cases.

Temporal arteritis often raises diagnostic problems. The first person to examine the patient may well be a dentist since the first symptoms of the disease are often stiffness of the masticatory muscles and impaired mobility of the lower jaw, reminiscent of mandibular dysfunction/TMJ pain and dysfunction. Other common symptoms are headache, tiredness, slight fever or other general symptoms. Two cases, both elderly women, referred to the Department of Stomatognathic Physiology, Göteborg, are possessed. The clinical features, histopathological findings and therapy are described and differential diagnostic problems are discussed.

Adrenal Cortex Hormones↗
PubMed1980

A photoelastic study of some biomechanical factors affecting the anchorage of osseointegrated implants in the jaw.

Photoelastic stress analyses of models of osseointegrated oral implants were performed, comprising an investigation of the installation practice and load experiments. In the load experiments, single-threaded and unthreaded implants were loaded in horizontal and vertical planes. The results of the installation experiments showed that pre-tapping and careful screwing down of the implant reduced stresses in the test piece. When tightening the screw forcefully, high stress concentrations arose at the margin of the implant site. In the load experiments a threaded implant was analysed in three different anchorage situations: case A, illustrating complete bone anchorage up to the head of the implant; case B, vertical bone loss; and case C, horizontal bone loss. An unthreaded implant was also analysed. The results indicated only minor differences between the three anchorage cases in the vertical load experiments. However, the threaded implants displayed a more favourable stress distribution than the unthreaded one. In the horizontal load experiments high stress concentrations arose at the margin of the test piece on the compression side at minor load levels (98 N), Anchorage cases B and C showed the highest stress concentrations. The results have clinical relevance, both for installation practice and for the design of the oral implant bridge.

Biomechanical Phenomena↗
PubMed1979

Bite force and oral function in complete denture wearers.

Oral function was evaluated in complete denture wearers by using a questionnaire, clinical examination and bite force measurements. Ten patients with satisifactory and ten with unsatisfactory dentures were studied and six of the latter patients were reexamined 1 year after the insertion of new dentures. The bite force values were compared with those obtained in ten dentate controls. No significant differences in bite force were found between the satisfactory and unsatisfactory denture groups. Individual values varied much in both groups. The six patients re-examined were satisfied with their new dentures and thought they had improved chewing but no significant increase of bite force was found. The maximal bite force was 5-6 times greater in the dentate subjects than in the denture wearers. Edentulous persons are very handicapped in masticatory function and even clinically satisfactory complete dentures are poor substitutes for natural teeth.

Adult↗
PubMed1979

Silent period and jaw jerk reflex in patients with osseointegrated oral implant bridges.

The silent period in the masseter and in the anterior portion of the temporal muscle during tooth tapping, the rate of tooth tapping and the jaw jerk reflex evoked by a tap on the chin were compared in individuals with oral implant bridges and with natural teeth. Thirteen women with osseointegrated oral implant bridges in one or both jaws, aged 42-59 years, were compared with 10 women, aged 42-64 years, with natural teeth. There was no difference between women, aged 42-64 years, with natural teeth. There was no difference between women with implant bridges and those with natural teeth in tooth tapping rate or in the occurrence, latency or duration of the jaw jerk reflex. A silent period during tooth tapping was found in 12 of the 13 women with implant bridges. The latency of the silent period was the same as in the subjects with natural teeth but the duration tended to be somewhat longer. The jaw jerk and the silent period were the same in individuals with implants in both jaws as in the whole implant group. It is therefore concluded that periodontal or mucous membrane receptors cannot be solely responsible for the silent period.

Adult↗
PubMed1979

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.

Adult↗
PubMed1979

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.

Adult↗