Fourteen impacted teeth in thirteen patients aged 9 to 17 years were either repositioned or transplanted, followed by postoperative orthodontic treatment. Successsful results were achieved in twelve of the teeth. In one tooth, ankylosis of the root prevented a successful outcome, and deficient bone healing of the alveolar process led to an unsuccessful result in a second tooth.
The outermost surface cell layer of the developing embryo, the periderm, arises from the initial single layer of ectoderm and is eventually exfoliated from the stratified epidermis, which has the same ectodermal origin. In this study, monoclonal antibodies against chicken limb bud ectoderm were generated and screened for those which stained the periderm. Four separate antibodies termed PD2, 3, 7 and 9 were obtained from 180 mixed hybridomas. These PD antibodies stained the periderm selectively at all stages examined (stage 20-42). By correlating the results of immunohistochemistry with observations made by transmission electron microscopy, it was revealed that PD antibodies stained both the squamous periderm at an early stage and rounded bulging peridermal cells just before exfoliation. Therefore we feel that PD antibodies may be useful in further systematic investigations of the development and function of the chicken embryonic periderm.
A study was conducted to determine whether granules of type III glass-ionomer cement (currently used as a fast-setting lining material and fissure sealant) implanted immediately after tooth extraction interfere with the time course of alveolar wound healing. Histologic examination of the entire socket showed normal progression of the healing process. Progressive bone neoformation in parallel with a decrease in the volume fraction of connective tissue was quantified by a histometric method up to 6 weeks after tooth extraction. The presence of glass-ionomer granules in the cervical third led to a small delay in bone formation by the first week but not thereafter, as also observed in the remaining regions of the alveolus (middle and apical thirds) which tended, in contrast, to show a larger amount of trabecular bone from the third week onwards. These results show that the material does not hinder the wound healing process, and in fact favors bone neoformation.
A study was conducted to assess the measurement accuracy of a laser three-dimensional measurement system for measuring facial profile and to investigate the changes in lower facial morphology caused by experimental protrusion of the upper incisors, and also to examine the relationship between the changes in lip form and lip thickness. The study subjects were 24 Japanese male dental students attending Nihon University School of Dentistry at Matsudo, who had normal overbite, overjet, and normal occlusion, and a good facial profile. The mean age was 23.2 years with a range of 21.5 to 25.8 years. Three-dimensional measurements obtained by a computerized 3D laser scanning system were used to evaluate facial morphology. The measurement error of this system was less than 0.5 mm in any three-dimensional linear mesurements. The stability and reproducibility of the recording procedure were evaluated. The changes in facial morphology caused by orthodontic treatment and orthognathic surgery were visualized in any direction by this three-dimensional graphic system. Lip thickness was not associated with changes in lip form. However, a relationship between the right and left corners of lip and lip thickness was noted. With regard to the ratio of changes in hard tissue and lips, the value of the original position for a 4 mm protrusion was not the same as that for a 4-8 mm protrusion. Also, the correlation of the changes in both groups was very low. The changes in lip thickness were associated with changes in stomion position, which in turn were related to the vertical change in the upper lip.
A study was conducted to investigate the timing relationship of temporomandibular joint (TMJ) sounds during mandibular movement, as evaluated by the location of the condyle, in relation to the articular fossa using axiograph recording. TMJ sounds during jaw opening and closing occurred over a wide range : opening sounds were observed within a range of 41-100 % of maximum opening, while closing sounds occurred within 1-80 % of maximum opening. In calculating the peak frequency of the joint sounds, it was noted that there was no correlation between the timing of the sound and its peak frequency. This study revealed that the acoustic characteristics of TMJ sounds may be unaffected by the location of the condyle.
We describe the enucleation of large radicular cysts to the maximum extent, and their treatment based on the concept of marsupialization and drainage after apicoectomy. Marsupialization requires a long period for healing, imposing a burden on the patient with regard to postoperative management. Considering this, together with the difficulty involved in the clinical diagnosis of radicular cysts, curettage of the cyst wall and drainage may be more effective for facilitating the healing process than use of marsupialization alone.