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Biomedical subjects

B Thilander

Publications and source records attributed to B Thilander.

At least 55 records · Page 3Linked to original sources
PubMed1989

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.

Adult↗
PubMed1988

Histochemical analysis of masticatory muscle in the growing rat after prolonged alteration in the consistency of the diet.

Changes in muscle function induce alteration in craniofacial bone growth. To study morphological changes after alteration of masticatory function, NADH-TR reductase and myofibrillar Ca2+-activated ATPase were assessed histochemically, after alkaline and acid pre-incubation, in sections from the anterior deep masseter and the anterior digastric muscles. Type IIA, IIB and transitional fibres of the anterior deep masseter but not of the digastric muscle were smaller in a soft-diet group than in a normal-diet group. There was a small percentage of type IIA fibres and a large percentage of type IIB fibres in the anterior deep masseter in the soft-diet than in the normal-diet group. The elevator muscles do not encounter the same functional demands on a soft as on a normal diet, and this causes different biting and chewing loads, which may in turn induce skeletal changes.

Animals↗
PubMed1988

Effect of orthodontic force on periodontal tissue metabolism. A histologic and biochemical study in normal and hypocalcemic young rats.

The relationship between force and degradation activity after application of orthodontic force is still obscure. Of particular clinical interest are the etiologic factors behind excessive root resorptions appearing in connection with orthodontic movement of teeth that has been proposed to be influenced by systemic factors regulating the tissue-degrading activity in periodontal tissues. Thus, the aim was, by histologic and new biochemical methods, to investigate the effect of orthodontic forces on the periodontal tissues in the normal and the hypocalcemic situation with secondary hyperparathyroidism. Root resorptions were induced in upper incisors of normal and hypocalcemic rats by subjecting the teeth to a moderate orthodontic force. In both groups the resorption of the roots occurred consistently in the vicinity of reorganizing areas of the periodontal ligament (PDL) with ongoing degradative activities and alveolar bone resorption. Furthermore, specific cell metabolic changes in alveolar bone and PDL in tension and pressure zones were detected and quantified by biochemical determination of alkaline phosphatase activity. This biochemical quantification of the metabolic changes together with the morphologic observations gave the clinically valuable information that the observed increase in occurrence and severity of root resorptions in moderate hypocalcemia was related to an increase in alveolar bone turnover. This study has shown that root resorptions were clearly related to the degradation process occurring in the vicinity of the hyaline zone and that in the hypocalcemic situation, the increase in root resorptions was related to an enhanced alveolar bone resorption. Thus, factors that minimize the time for resorptive/degradative activity should be discussed in this context rather than force per se.

Alkaline Phosphatase↗
PubMed1987

Some periodontal tissue reactions to orthodontic tooth movement in monkeys.

The purpose of the experiment reported was to study soft tissue changes at teeth which were orthodontically moved into areas with varying thickness and quality of periodontal tissues. The maxillary central incisors and first premolars in 5 adult monkeys were used as experimental teeth. 6 months prior to the start of the orthodontic treatment phase, the maxillary second premolars were extracted. By surgical means, areas with varying width of the keratinized gingiva were established in the incisor and premolar region. Following a clinical baseline examination which involved assessments of gingival width, location of the gingival margin in relation to cemento-enamel junction and probing attachment level, fixed orthodontic appliances were inserted in order to bodily move the two contral incisors in labial direction through the alveolar bone envelope and the first premolars in distal direction into contact with the first molars. Orthodontic forces were applied for a period of 3-4 months. The lateral incisors and first molars were selected as non-moved control teeth. After the experimental teeth had been retained in their new positions for 1 month, the clinical examination was repeated. Tissue blocks containing test and control specimens were subsequently dissected and prepared for microscopic analysis. The analysis included histometric assessments of loss of connective tissue attachment and height of alveolar bone. The results showed that at every second labially moved incisor, the gingival margin had become displaced in apical direction. The degree of displacement, however, was small and only at 2 teeth accompanied by loss of connective tissue attachment. Throughout the study, these particular teeth also showed obvious signs of gingival inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Process↗
PubMed1987

A histologic comparative study of the midpalatal suture and periodontal ligament tissue in the beagle dog.

The present investigation describes the morphological difference between the suture and the periodontal ligament in beagle dogs. Specimens from five beagle dogs, 2 yr old, containing the anterior portion of the maxilla were used. Following routine histologic preparations frontal sections were cut with the microtome. The sections were stained and studied in the light microscope. The fibers in the midpalatal suture seemed coarser and less organized than the fibers in the periodontal ligament tissue. The vessels in the suture had thicker walls than the vessels in the periodontal ligament. A probable reason for the morphological differences between the two tissues is discussed.

Animals↗
PubMed1986

Transalveolar transplantation of maxillary canines. An alternative to orthodontic treatment in adult patients.

Transalveolar transplantation of 31 maxillary canines in 26 patients was performed. Fixed orthodontic appliances were used for fixation for 6 to 8 weeks. All the transplanted teeth were firmly affixed in the new positions 3 to 6 months postoperatively. Complete bone regeneration and an attached gingiva with a stippled surface buccally and a normal pocket depth were observed 1 to 2 years postoperatively. These positive treatment results indicate that transalveolar transplantation is a useful alternative in the treatment of impacted maxillary canines in selected patients.

Adolescent↗
PubMed1986

The role of the orthodontist in the multidisciplinary approach to periodontal therapy.

The effects of orthodontic tooth movement upon the supporting tissues of teeth with periodontal breakdown are conflictingly reported. Recent studies in beagle dogs have, however, enlarged our understanding of the effects of tipping and bodily movements of teeth and of factors important in retention after orthodontic treatment. Such treatment should always be preceded by the treatment of periodontal inflammation and the elimination of deep pockets.

Adult↗