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Biomedical subjects

T Haraldson

Publications and source records attributed to T Haraldson.

At least 37 records · Page 2Linked to original sources
PubMed1989

Perception of jaw position during different conditions.

The perception of jaw position, measured as the ability to produce a predetermined mandibular posture repetitively, was recorded under different experimental conditions. A control group of asymptomatic subjects was tested before and after anesthesia of the TMJs and after fatigue of the masticatory muscles. Groups of patients with craniomandibular disorders of arthrogenic or myogenic origin were also tested. None of the experimental variables affected position perception, and the patient groups did not differ from each other or the normal group in perception of jaw position. The possible clinical value of such recordings in differential diagnosis is therefore open to question.

Fatigue↗
PubMed1988

Gross anatomy of the craniomandibular joint and masticatory muscles of the dog.

The craniomandibular joint (CMJ) and masticatory muscles in 15 dogs (Canis familiaris) were dissected. The major structures were fossa, disc and condyle surrounded by a thin fibrous capsule. The horizontally orientated temporal fossa had a pronounced tubercle anteriorly. Posteriorly, a retroarticular process curved backwards. This fossa and process closely surrounded the condyle. The disc was thin. The cylindrically-shaped condyle was elongated in the medio-lateral direction, situated at right angles to the sagittal plane. The lateral pterygoid muscle was poorly developed; the temporalis was by far the largest masticatory muscle. These findings support the assumption that the movements of the canine mandible are mainly hinge-like. Furthermore, the canine CMJ differs in many respects from the corresponding anatomical structures in the domestic pig, as well as in man.

Animals↗
PubMed1988

Spontaneous temporomandibular joint arthropathy in MRL-lpr/lpr mice.

The temporomandibular joint (TMJ) in spontaneously arthritic MRL lpr/lpr (MRL/l) mice has been histologically analysed. After decalcification and standardized preparation of the joint tissue, histological sections were examined for presence of synovial hypertrophy, synovial villi, pannus tissue, erosions, cysts and signs of periarticular inflammation. In 12 of 13 TMJs examined, histopathological changes indicating a state of arthropathy were found. The most prevalent finding was synovial proliferation, which was frequently detected at the insertion of the synovial membrane to the bone. Two or more signs of inflammatory involvement including synovial proliferation, pannus tissue and bone erosion were seen in 5 mice with a predominance among the oldest mice (greater than or equal to 5 months of age). No lymphocytic cell infiltration was found in the analyzed synovial tissues of the TMJ. In contrast, lymphocytes were observed in the vicinity of periarticular blood vessels and tendons. It is concluded that the TMJ is frequently involved in the arthritic disease of autoimmune MRL/l mice.

Animals↗
PubMed1988

Endurance tests of the masticatory system on different bite force levels.

Endurance tests of the masticatory system were performed in three different groups of healthy volunteers in order to investigate the relation between bite force and endurance time on different force levels. The subjects clenched a bite fork until exhaustion. Some tests were performed with and others without visual feedback of the exerted force. It was found that the subjects could sustain the maximal bite force practically at the same level during the recording time with visual feedback. The exerted force varied during the non-feedback recordings and generally decreased on the forceful levels. The average endurance time increased at lower bite force levels and the relation between force and endurance time is described. The average integrated time-force areas did not differ between the test levels. It is concluded that endurance tests in the clinic may be performed on submaximal bite force levels.

Adult↗
PubMed1988

Oral function in subjects with overdentures supported by osseointegrated implants.

Nine subjects treated with overdentures on osseointegrated implants in the mandible were functionally evaluated before and after treatment. The last recordings were performed 1 yr after treatment. The evaluation comprised a subjective and a clinical examination. Measurements of bite force and of chewing efficiency were also performed. The bite force was measured during gentle biting, biting as when chewing and biting with maximal effort. Almonds were used as test food. All subjects improved subjectively as well as clinically after treatment. The bite force during gentle biting increased on average from 17.3 N before treatment to 24.0 N 1 yr after treatment. A corresponding improvement of biting as when chewing was also found, from on average 24.0 N before to 38.7 N after treatment. The maximal bite force increased from on average 74.6 N at the baseline examination to 131.5 N at the 1-yr follow-up. The chewing efficiency improved from Ci = 4 (Median value) before treatment to Ci = 2.8 (Median value) after treatment. It is concluded that treatment with an overdenture supported by osseointegrated implants in the mandible improves oral function compared to the situation before treatment.

Aged↗
PubMed1988

A 10-year follow-up study of the masticatory system after treatment with osseointegrated implant bridges.

Twenty-one patients with osseointegrated implant bridges (OIB), with an average age of 65 yr, were functionally examined at a 10-yr follow-up. Altogether 27 OIBs, supported by 138 fixtures, were examined. The examination comprised an anamnestic and clinical examination and registration of bite force. 90% of the patients were very satisfied with the outcome of the treatment. According to the anamnestic dysfunction index (Ai), 80% of the patients were symptom free in their masticatory system. The occlusal state was found to be good. Seventy-five percent of the patients were found to have only mild dysfunction of their masticatory system or to be symptomless according to the clinical dysfunction index (Di). The bite force ranged from 3 to 118 N at gentle biting, from 25 to 250 N at "biting as when chewing" and from 77.5 to 495.5 N at maximal bite force. On average the bite force had improved significantly at all bite-force levels tested compared to an examination 10 yr earlier. It is concluded that oral function in patients with OIBs is very favorable.

Aged↗
PubMed1988

Skin surface temperature over the temporomandibular joint and masseter muscle in patients with craniomandibular disorder.

Skin surface temperature was measured over the temporomandibular joint (TMJ) and over the origin of the superficial portion of the masseter muscle in 59 patients with craniomandibular disorder of different character. Forty patients suffered from disorder of muscular origin, 11 from non-specific arthritis and 8 from symptomatic osteoarthrosis. The degree of mandibular dysfunction was estimated by the clinical dysfunction score and index. The temperature was measured by a thermistor applied to the skin. The clinical dysfunction score of the patients varied between 1 and 25 units. Eleven patients had a clinical dysfunction index of I, 22 had II and 26 had III. The temperature over the TMJ varied between 31.3 degrees C and 36.7 degrees C, and over the masseter muscle between 31.1 degrees C and 35.5 degrees C. The patients with unilateral tenderness to palpation of the TMJ and who were diagnosed to have TMJ arthritis had a higher skin surface temperature over the symptomatic than non-symptomatic joint. It was concluded that tenderness to palpation of the TMJ in patients with TMJ arthritis is associated with raised skin surface temperature over the joint.

Adolescent↗
PubMed1987

Long-term effect of intra-articular injections of sodium hyaluronate and corticosteroid 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.

Adult↗
PubMed1987

Periodontal status and bruxism. A comparative study of patients with periodontal disease and occlusal parafunctions.

This study investigated a possible association between bruxism and severity of periodontal disease. Subjects consisted of 51 patients (mean age 47.3 years) referred to the Department of Periodontology for treatment of moderate to severe periodontal disease (Perio-group) and 40 patients (mean age 48.9 years) referred to the Department of Stomatognathic Physiology for treatment of symptoms related to bruxism (Bruxism-group). Examination of the two groups included measurements of the alveolar bone height, probing attachment level, tooth mobility, and attrition of teeth. A questionnaire was also used to gain information on the patient's awareness of bruxism and tooth mobility. Awareness of clenching and/or grinding was reported by 57% of patients in the Bruxism-group and 24% of patients in the Perio-group. The perio-patients reported significantly higher frequency of tooth mobility than did the bruxism-patients. Alveolar bone loss, attachment loss, and tooth mobility were significantly more pronounced in the Perio-group than in the Bruxism-group. The Bruxism-group showed a higher frequency of tooth attrition than the Perio-group. Periodontal disease and bruxism seldom occurred in the same individual, and the results indicate that the two phenomena are in general not closely associated.

Adult↗
PubMed1987

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.

Adolescent↗
PubMed1987

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.

Adult↗
PubMed1987

Occlusal perception and bite force in young subjects with and without dental fillings.

Interocclusal thickness discrimination (occlusal perception) and bite force was investigated in 29 young adults (16-18 years old). Thirteen individuals had intact dentitions (group I), whereas 16 individuals had minor restorations in posterior teeth (group C). Bite force was tested during 'gentle biting', 'biting as when chewing', and 'maximal clenching'. Endurance tests and bite force discrimination tests were also performed. The best occlusal perception was found in the incisor region in both groups, whereas the occlusal perception was somewhat smaller in the canine and premolar regions. Fifty-four per cent of the subjects in group I and 81% in group C reached certain perceptiveness at the 9-micron level. There were no statistically significant differences between test locations or groups, however. Group I had a significantly greater bite force in the incisor region during gentle biting than group C. The maximal bite force was on an average 532 N in group I and 516 N in group C. In the endurance tests, group I could withstand the muscle fatigue longer than group C, but the difference was not statistically significant. In the bite force discrimination test both groups showed a similar pattern. Group I showed a closer correlation than group C between recordings in a test of stepwise increase of force and a randomized test of five force levels. Both groups appeared functionally normal in the masticatory system and reacted similarly in the physiologic experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Gross anatomy of the mandibular joint and masticatory muscles in the domestic pig (Sus scrofa).

The mandibular joint (MJ) and masticatory muscles in 15 domestic pigs, aged 1 year, were investigated during and after dissection. The joint consisted of a fossa, disc and condyle surrounded by a ligamentous capsule. The fossa was almost flat, slightly convex antero-posteriorly and concave medio-laterally; the disc was biconcave and the condyle oval. The long axis of the condyles formed an anteriorly orientated angle to the frontal plane. The masticatory muscles were similar to human ones except for the pig zygomatico-mandibular muscle. The resemblance between the anatomy of the porcine and human joint and masticatory muscles makes the pig a useful animal for functional studies of the masticatory system.

Animals↗
PubMed1986

Facial asymmetry and unstable occlusion due to poliomyelitis. Report of a case.

A case, referred to the Department of Stomatognathic Physiology, Göteborg, with an unstable occlusion is presented. There was a facial asymmetry and the bony morphology differed markedly between the sides. No EMG activity in the masticatory muscles could be detected on the left side. It was diagnosed as a probable sequela to poliomyelitis in the childhood. The impact of altered muscle function on the bony structures and dentition is discussed.

Adult↗
PubMed1985

The short-term effect of intra-articular injections of sodium hyaluronate and corticosteroid on temporomandibular joint pain and dysfunction.

The short-term effect of intra-articular injections of sodium hyaluronate and a corticosteroid (betamethasone) was compared in a sample of 33 patients who had pain and tenderness to palpation in the temporomandibular joint of at least six months duration that had not responded to previous conservative treatment. The two drugs were randomly allocated to the patients. A volume of 0.5 ml of the drug was 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. Both drugs reduced the symptoms and signs significantly, and no statistically significant difference in effect could be found between drugs in this regard. The results indicate that the difference between the drugs in terms of short-term therapeutic effects is small, and that sodium hyaluronate could be used as an alternative to corticosteroid for patients who have signs of TMJ inflammation, especially for those who have symptomatic osteoarthrosis.

Adult↗