An angular measurement was conducted on 12 cases with cross bite and 18 cases without among the patients who underwent surgical orthodontic treatment for mandibular protrusions (true Class III) and the following results were obtained. 1) An angle measurement for each plane against X axis is helpful for a judgement of facial symmetry. 2) The distortion of each portion (each plane) can be judged from the angular difference of each plane. 3) The angle measurement seems to be useful enough in planning for paper surgery.
In our previous study carried out in 1994, we found 49 patients with unilateral cleft lip and palate (UCLP) among 51 patients with cleft lip and palate who visited the Department of Orthodontics, Nihon University Dental Hospital at Matsudo. In particular, patients with cross-bite (anterior crossbite) UCLP were predominant, accounting for 21 individuals (41%).In the present study, we reviewed 79 patients with malocclusion including 21 with anterior crossbite UCLP, who represent the largest subpopulation among patients with cleft lip and palate. These 21 patients were compared with other UCLP patients showing normal bite with regard to morphological differences evident in lateral roentgenographic cephalograms, to establish a proper policy of orthodontic diagnosis and treatment of their condition.The anterior cross-bite UCLP group showed differences in the skeletal pattern and the denture to skeletal pattern from the other patient groups except for the mesio-distal relationship. The anterior cross-bite UCLP group had cross-bite of the concave type, while the normal bite UCLP group had malocclusion of the convex type accompanied by maxillary overdevelopment. Thus, it is suggested that normalization of reversed occlusion leads to favorable growth of the upper jaw in UCLP patients with anterior cross-bite.
In the present survey, the authors examined a total of 426 boys and girls from the 2nd to 6th grades, using prepared questionnaires, concerning their intelligent understanding of oral health according to grade, at the same time, the relationship of this understanding to dental instruction contained in school curricula. A similar survey made by Fukui of our Department before the revision of the elementary school curriculum in 1959 was used for comparative analyses.As a result, it was found that, compared with boys and girls of other grades, those in the 5 th grade had a much better understanding of oral health. These findings can be attributed to the relatively high frequency of instruction regarding teeth in the natural science and physical education curricula for this particular grade.In the elementary school curriculum for 1969 in which natural science subjects were mainly taught in the 2nd, 4th and 6th grades, Fukui found that boys and girls in the 4th and 6th grades had much better understanding than those in the 5th grade. The present survey findings present a marked contrast to those of Fukui in this regard.As for the understanding of other related dental matters, on the other hand, the degree did not vary any appreciably from grade to grade but it was more or less in proportion to the advance in grade. As a possible reason for this, it may be concluded that extracurricular activity as well as home instructions exerted a more beneficial influence than school subjects directly.
In recent years there have been many reports on studies related to the temporomandibular joint (TMJ) in orthodontic treatment, but an adequate system of diagnosis and treatment has yet to be established, and they often cause considerable difficulty clinically. The patient in this case report sustained generalized contusions, a cerebral concussion, a midline fracture of the mandibular corpus, and bilateral fractures of the condylar process of the mandible when he fell asleep while driving a car and collided with a truck. Because non-surgical reduction was impossible, mandibular condylectomy was performed, and when orthodontic treatment was attempted to improve the open bite that persisted as a sequela of the accident, the favorable results were obtained, as described below. 1. The open bite was corrected by the orthodontic treatment, and the impairment that remained as a sequela resolved. 2. The mandibular condyles were removed during surgical reduction, and the mouth opening disturbance, the TMJ pain, and the TMJ noise resolved. The patient was able to go about his everyday life unimpaired, with hardly any awareness of limitation of jaw movement, and this situation remained unchanged even after the orthodontic treatment was performed. (J. Oral Sci. 40, 1-8, 1998)
According to the authors' clinical experience, malocclusion accompanied by temporomandibular joint disorder involves mainly cross bite, open bite, deep overbite or axillary protrusion. However, it is possible that the symptoms of this disorder are associated with other types of malocclusion or even with nearly normal occlusion. In fact, it can be said that temporomandibular joint disorder may develop with any type of occlusion.This paper reports a case of open bite accompanied by temporomandibular joint disorder occurring in a patient who visited our hospital because of pain in the left temporomandibular joint region, vertigo and partial deafness. In this patient, the temporomandibular symptoms disappeared after orthodontic treatment. The patient received no particular treatment thereafter because follow-up observation confirmed that the therapeutic results were favorable without any relapse of the symptoms of temporomandibular disorder. The positions of the temporomandibular joint and mandibular condyle were determined in lateral-oblique radiograms obtained using our radiographic system, by which the mandibular condyle is radiographed using a projection consistent with its long axis.
