Zennosuke Kinoshita

Steiner cephalometric norms for Japanese and Japanese-Americans

Abstract Numerous independent cephalometric studies of Japanese and Japanese-Americans have been conducted, and the mean values obtained from these studies have been compared with the Caucasian norms of the Steiner analysis. Because of the differences in the criteria used in the selection of the subjects, comparison of the data of the various studies has led to confusion and misunderstanding. The samples selected by these investigators consisted of subjects with normal occlusion, whereas the samples of Steiners study consisted of well-treated orthodontic patients with good facial profiles. From these samples one case that he thought was the “best,” meeting the requirements of his concept of an ideal case, was selected and the values from this one case were used as the “ideal reference norms.” An attempt was made in this study to follow closely Steiners methods in deriving the “ideal reference norms” for Japanese and Japanese-Americans. One case was selected from the fifty cases as being the “best,” that is, as meeting the requirements of our concept of good occlusion, incisor relationship, and balanced facial profile. 1. 1. Reference norms used in the Steiner analysis were established for Japanese and Japanese-American patients. 2. 2. A comparison of these norms was made with those of Steiners ideal and with the mean values of Miura and colleagues. 3. 3. Ideal and “acceptable compromises” were established for patients of Japanese ancestry (Fig. 4). 4. 4. Steiners most valuable teaching (“These values are useful as guides but must be modified for individuals”) is emphasized.

Craniofacial pattern of Class III deciduous dentition

The purpose of this study was to investigate the morphological characteristics of the cranio-dento-facial complex of children with deciduous dentition and Class III malocclusion. Forty Chinese children in Taiwan with normal occlusion and 40 with Class III malocclusion in deciduous dentition were selected for cephalometric analysis. Mandibular length was significantly greater and the mandible was situated farther forward in the Class III group. The maxilla was also slightly backward in this group, perhaps in association with the shorter maxillary length. The mandibular incisors were tipped lingually to compensate for the intermaxillary skeletal dysplasia and the maxillary incisors were tipped lingually by the retroinclined mandibular incisors.

Two Similar Skeletal Class III Cases Treated by Orthognathic Surgery and by Orthodontic Procedure.

Methods of evaluating the need for orthognathic surgery during orthodontic treatment was investigated by comparing two similar cases of skeletal class III malocclusion.Cephalometric analysis of the maxillary and mandibular skeletal positions is essential in determining the need for surgical orthodontic treatment. However, surgery in some borderline cases is optional.Cephalometric analysis indicated that case 1 should be treated by orthognathic surgery, while case 2 should be corrected by orthodontic treatment only. The effect of surgical and non surgical treatment on ANB, APDI, AB-MP, Wylies assessment, and AO-BO was evaluated.The following results were obtained:1. Several analyses should be done in determinig the need for orthognathic surgery in the treatment of skeletal class III malocclusion.2. Skeletal correction requires evaluation of the antero-posterior skeletal discrepancy and vertical discrepancy.3. Dental correction requires evaluation of the inclination of the occlusal plane and relationship of the first molars.4. Esthetic correction requires analysis of esthetics.

The Evaluation of Preoperative Clinical Examination for the Patients with Jaw Deformities in Our Department

Orthognathic surgery under general anesthesia was performed on 255 patients from April 1982 through December 1992 at the First Department of Oral and Maxillofacial Surgery, Osaka Dental University. Based on preoperative examinations of those patients, the following prevalence rates of diseases were obtained, reinforcing the need for preoperative examinations:1. Anemia was found in21patients (8.2%); two (2.3%) of them were male and19 (10.9%) were female.2. Abnormality of liver function was found in 17 patients (6.7%); nine (11.1%) were male and eight (4.6%) were female.3. Arrthythmia was found in 6 patients (2.4%); one (1.2%) was male and five (4.6%) were female.4. Allergic disease was found in 47 patients (18.4%); 15 (18.5%) were male and 32 (18.4%) were female. Eighteen out of 47 patients suffered from asthma.5. Hyperthyroidism was found in two patients (0.8%).

Functional Observation of Skeletal Class III Patients Passed Long-Term after Retention

The goal of this study was to develop objective functional method of evaluating treatment systems for patients with jawdeformations, a treatment which is expected to increase in the future. We attempted to discern the characteristics of the recovery process ofpostoperative jaw motility and muscle function by studying preoperative and postoperative skeletal class III patients and comparing themwith normal controls, placing emphasis on factors outside the treatment period of the jaw deformation patients.Using skeletal class III patients as controls, we measured jaw movements and muscle function over a period extending beyond that of thesurgical orthodontic treatment, which includes the periods prior to initiation of the preoperative orthodontic treatment and aftercompletion of the retention.The following results were obtained;1) Orthognathic surgery not only corrected the form of the malocclusion, but is also improved the function of the masticatory system.2) A new masticatory form was essentially established by the maxillomandibular relationship created by the orthognasthic surgery.3) Masticatory function in the patients was an improvement over that before the operation, and was either as good as the function in personswith normal occlusion or better.4) Maintenance of the occlusion during the postoperative recall seemed an important factor in the process of recovery of masticatoryfunction.