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.
We analyzed the masticatory movement patterns of patients with skeletal Class I or III malocclusion who had lateral deviations of the jaw and were treated using orthognathic surgery. The aims of this study were (1) to compare the chewing patterns at initial examination(T1), after removal of each participantʼs orthodontic appliance(T2), and after ≥1 year of maintenance(T3), and(2)to analyze the effects of different chewing patterns on changes in the axial inclination of the first molars. A Gnatho-Hexagraph III was used to measure the chewing patterns(with six degrees of freedom)of 21 participants(mean age: 23.2±5.4 years)with a menton deviation≥4 mm from the midline. A three-dimensional digital scanner was used to measure the axial inclination of the maxillary and mandibular first molars. Participants with normal chewing patterns on both the affected and unaffected sides at T1 had the same pattern at T2 and T3. In addition, 50% of the participants with reversed chewing patterns on the affected side at T1 exhibited normal patterns at T2, while 33.3% retained their original reversed pattern. Compared to the participants with normal chewing patterns, those with reversed patterns showed a significantly greater change in the inclination of maxillary and mandibular first molars on the affected side between T2 and T3. Palatal, maxillary first molar, and mandibular first molar widths showed similar results. Moreover, participants with normal chewing patterns had few changes in the buccolingual molar inclination; hence, the orientation of the molars remained unchanged.
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)
Authors have developed a mandibular retraction system in a rat that was constructed by arms having a metal mesh, an incisor metal cap, a pair of closed coil springs and a soft plastic collar. The merit of this system is that the anchor is very stable because it is made on the parietal bones, and the direction and load of the traction are invariable regardless of head position of the rat compared to the previous methods in which the anchor was made on the neck collar of a rat. Seventy of 8-week-old male Wistar rats were divided into five groups that were intact, collar, sham operation, straight-pull and high-pull. The anchor was implanted with a metal mesh into the subperiosteal space of the parietal bones just in front of the lambda suture of a rat. The coil spring attached on the sliding hook on the arm was connected with a hook soldered with an incisor metal cap. Therefore, the mandible was retracted in the TMJ direction (straight-pull) and some were 20 degrees upper than TMJ (high-pull) for 15 days at a tension of 10 g. All operations except for traction by the coil springs were performed on a rat in the sham operation group. Only the plastic collar was set on the neck in the collar group. Mandibular retraction for 15 days showed significant inhibition of the sagittal growth of the mandible in both high- and straight-pull groups. No inhibition of sagittal cranial growth was observed according to morphometrical and microscopical investigations.(ABSTRACT TRUNCATED AT 250 WORDS)
Metabolism by peptidases plays an important role in modulating the levels of biologically active neuropeptides. One of these neuropeptides, substance P (SP), a component of gingival crevicular fluid (GCF), may exponentiate the inflammatory process during orthodontic tooth movement. The aim of this study was to investigate the GCF levels of SP in patients using different bracket systems. Subjects were 10 patients (four males, six females; mean age, 25.1 ± 4.4 years) undergoing orthodontic movement (leveling) in the maxilla. Conventional brackets were placed on the left side, while the teeth on the right received self-ligating brackets. The teeth on the mandibular left side without any orthodontic attachments served as controls. GCF was sampled at 0, 1, 24, and 168 hours after initiation of treatment. Prevention of plaque-induced inflammation allowed assessment of the dynamics of mechanically stimulated SP levels in the GCF, which was determined using commercially enzyme-linked immunoabsorbent assay (ELISA) kits. GCF levels of SP for the Damon System sites were significantly lower than for the teeth with conventional brackets at 24 hours. This result indicates that the Damon System inhibited an increase in the amount of SP in the GCF. Thus, the Damon System is useful to reduce the inflammation and pain resulting from orthodontic forces.
