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Biomedical subjects

M Sebata

Publications and source records attributed to M Sebata.

12 recordsLinked to original sources
PubMed1992

An orthodontic study of temporomandibular joint disorders. Part 1: Epidemiological research in Japanese 6-18 year olds.

Malocclusion is considered one of the etiological factors of temporomandibular joint disorder (TMD). The purpose of this study was to investigate the prevalence of TMD and the relationship between TMD and the type of occlusion. The sample consisted of 7337 Japanese children, 6-18 years old, 3219 boys and 4118 girls. TMD symptoms were recorded as well as the type of occlusion in children with TMD. The prevalence of TMD overall was 12.2%. The prevalence increased with age and was slightly higher in girls (13%) than in boys 11.1%. This difference was not statistically significant. Joint sound as the only symptom was more common in younger subjects. TMD symptoms seemed more complicated with age when pain and abnormal jaw movement combined with sound. Joint sound was the most common symptom (89.3%), followed by the combination of sound and pain (2.2%). The incidence of other symptoms was under 1%. In subjects with TMD, 24.9% exhibited crowding, 20.1% had excessive overjet, 6.8% deep bite, 6.3% edge-to-edge bite, 5.6% anterior crossbite, 5.4% open bite, and 3.8% posterior crossbite. Morphologically normal occlusion was observed in 27.1%. In this study, many subjects with TMD had malocclusions. Early treatment may be important in the prevention of severe TMD. Although those with morphologically normal occlusions were included, a more detailed study concerning other causes of TMD is needed also.

Adolescent↗
PubMed1990

[Longitudinal observation of condylar position in anterior crossbite at the mixed dentition during orthodontic treatment].

We investigated the condylar position by transcranial radiography which can be put daily clinical use easily. The patients are 8 anterior crossbite at the mixed dentition (4 functional crossbite and 4 skeletal crossbite). We observed their condylar positions before treatment (average age is 9.3 years old), after correction of overbite (average age is 10.0 years old) and 3-4 years after correction of overbite (average age is 14.0 years old). The results were as follows: 1. Condylar position of 7 cases changed after correction of overbite. The differences between right and left condylar position of six in seven cases had been recognized before treatment decreased after correction of overbite. Their condylar position were stable during the observation period of 3-4 years after correction of overbite. The condylar position of the other one case closed to fossa and then relapsed 3-4 years later. 2. Condylar position of only one case hasn't changed during the observation. 3. In functional crossbite cases, there were some differences between right and left condylar position before treatment, but no differences after crossbite correction. In skeletal crossbite cases, there was no tendency of the changing on their condylar position through treatment. 4. The changing to same direction was observed in the decrease of differences on condylar position and in the result of frontal cephalogram analysis. 5. There wasn't special relationship between changing of condylar position and orthodontic appliances. 6. TMJ dysfunction was observed in the case which has significant difference in its condylar positions before treatment and in the other case in which difference was not corrected after treatment. We recognized the usefulness of transcranial radiography for orthodontic treatment.

Child↗
PubMed1979

The effect of acid etching on the cervical region of the buccal surface of the human premolar, with special reference to direct bonding techniques.

Etching action on the cervical enamel compared to the central and incisal enamel of the buccal surfaces of premolars was investigated by using the scanning electron and optical microscopes. In SEM observations, the etched cervical enamel surface showed a pitted feature with no prism delineation, regardless of the prolonged etching time and the removal of enamel surface. The etched central and incisal enamel surface showed the characteristic prism-end structure. In optical microscopic observations, the tags formed at the cervical region were shorter and less numerous than those formed at the central and incisal enamel surfaces.

Acid Etching, Dental↗