Masaki Yamaki

Nonsurgical Treatment of Adult Open Bite Using Edgewise Appliance Combined with High-Pull Headgear and Class III Elastics

This case report describes the effect of a combination of high-pull headgear and Class III elastics on the nonsurgical treatment of an adult open bite. The 19-year 1-month-old Japanese female presented with the anterior open bite of 4.0 mm and mild crowding. She had a skeletal Class II but a Class III molar relationship due to a severe proclination of the mandibular dental arch. Unilateral congenital missing premolars caused a discrepancy between the facial and dental midline. After extraction of two premolars and the impacted mandibular third molars, nonsurgical therapy was performed using the standard edgewise appliance combined with a high-pull headgear and Class III elastics. The successful treatment outcome and stability of the final occlusion indicates that a combination of high-pull headgear and Class III elastics is one of the effective devices in the nonsurgical treatment of open bite and, is especially helpful in uprighting the mandibular dental arch.

Craniofacial cephalometric analysis of Bangladeshi and Japanese adults with normal occlusion and balanced faces: A comparative study

Aims: To determine the cephalometric norm among Bangladeshi adults and to investigate the differences in craniofacial morphology compared with Japanese and Caucasian normative data. Materials and Methods: Cephalometric radiographs were obtained from 46 Bangladeshi males (mean age 23.8 years) and 52 Bangladeshi females (mean age 24.6 years). Inclusion criteria were the following: Both parents from the same ethnic group, class-I occlusion with an arch length discrepancy less than 2 mm, overbite and overjet from 2 to 4 mm, balanced face, all teeth present except third molar, no previous orthodontic treatment, and no prosthetic replacement of teeth. Nine angular and five linear measurements were constructed for skeletal hard tissue analysis, four angular and six linear measurements for dental hard tissue analysis, and two angular and seven linear measurements for soft tissue analysis. Mean and standard deviations of measurements were determined for each gender. Polygonal chart and profilogram were made. Independent t-test was used to determine differences. Results: The present Bangladeshi population has a smaller lower face height (P<0.01) and the antero-posterior position of the maxilla and mandible was found to be significantly (P<0.01) more protruded compared with the Japanese and the Caucasian norms. Significantly (P<0.01) more protruded upper incisor, less steep occlusal plane, and thinner soft tissue chin were the characteristics in Bangladeshi adults. Conclusions: Relative to the cranial base (SN), the maxillo-mandibular complex was more anteriorly placed compared with the Japanese and Caucasian adults. Further, the effective length of the maxilla and mandible was shorter compared with the Japanese and Caucasian adults. These findings should be considered carefully during orthodontic treatment planning of Bangladeshi adults.

Relapse tendency in maxillary arch width in unilateral cleft lip and palate patients with different maxillary arch forms.

Objective: The aim of this study was to investigate the relapse tendency in the maxillary dental arch widths in unilateral cleft lip and palate patients with different types of maxillary arch form. Subjects: Thirty-two unilateral cleft lip and palate patients treated by one-stage surgical palatal closure were included. The subjects were divided into three groups according to the types of the maxillary arch forms: group A, symmetrical arch form; group B, collapse of minor segment; group C, collapse of both segments. Methods: Using dental casts obtained at three different times, relapse in the intercanine, interpremolar, and intermolar widths in each group was assessed and differences between groups were investigated. Results: Patients in group A showed stable results in all measurements. Patients in group B showed posttreatment relapse in the intercanine width only, whereas patients in group C demonstrated significant posttreatment relapses in the interpremolar and intermolar widths. Comparison between groups showed more significant relapse in the interpremolar and intermolar widths of group C than in those of group B. Conclusion: The types of the maxillary arch forms in unilateral cleft lip and palate patients might play a stronger role in the stability of the maxillary dental arch widths after orthodontic treatment in patients with collapse of both segments and a severe degree of maxillary narrowness.

A cross-sectional study on the relationship between craniofacial morphology and the coronoid process

Although there have been some reports on the relationship between craniofacial morphology and the activity of the temporal muscle attached to the coronoid process, such relationship is still unclear. The aim of the present study was therefore to investigate the relationship between the coronoid process and overall craniofacial morphology using lateral cephalograms of 60 female subjects (mean age 9.6 years) without mandibular deviation. Statistical testing was undertaken using stepwise regression analysis. Anterior coronoid marginal depth correlated negatively (r = 0.71) with gonial angle, SNA, and overjet. The coronoid angle also correlated negatively (r = 0.86) with both the vertical and horizontal lengths from sella to the coronoid tip as well as with the horizontal length from sella to the posterior ramus margin. Furthermore, the coronoid length correlated positively (r = 0.61) with the coronoid angle and the anterior coronoid marginal depth. The coronoid width was also positively (r = 0.69) correlated with overbite. Coronoid process morphology is related not only to mandibular morphology and position but also to maxillary position and the dental relationship in the anterior region. It therefore seems clear that coronoid process morphology might be related to temporal muscle functioning and its associated craniofacial morphological measurements.

Mesiodistal tooth width and tooth size discrepancies of Yemeni Arabians: A pilot study

Objectives: The aims of this study were to determine the mean mesiodistal tooth size width and Boltons anterior and overall ratios, find any possible sex differences, and study the frequency of tooth size discrepancies among Yemeni population and if there is a difference in tooth size between the right and left sides. Materials and Methods: 176 subjects aged 13–25 years (94 females and 82 males) with different types of malocclusions (94 Angle Class I, 37 Class II division 1, 36 Class II division 2, and 9 Class III) were included in the present study. The mean mesiodistal tooth size width and Boltons ratios were determined. Results: The results showed that males had significantly larger teeth than females. The prevalence rates of clinically significant discrepancy greater than 2 SD were 29.53% and 14.20% in the anterior and overall tooth size ratios, respectively. Further, the results revealed that there were no significant differences in the tooth size width between right and left sides. Conclusion: The findings of the present study indicate that there was no significant difference between Boltons ratio and that of Yemeni population.

Orthodontic treatment combined with tooth transplantation for an adult patient with a missing mandibular first molar: Long-term follow-up

A Japanese woman, age 29 years 8 months, had a missing mandibular left first molar, bimaxillary dentoalveolar protrusion, and crowding. She had a skeletal Class II relationship and a long face with a steep mandible. She had previously undergone root canal treatment for the mandibular right second premolar, and the mandibular left third molar was impacted. The maxillary left first premolar was extracted for autotransplantation to the mandibular left first molar region. After confirmation of a favorable prognosis for the transplanted tooth, the maxillary right first premolar, the mandibular right second premolar, and the impacted mandibular left third molar were extracted for orthodontic treatment. The active orthodontic treatment period was 32 months. The patient returned for follow-up records 12 years 7 months after the active treatment, and her facial profile and occlusion were well maintained. At 13 years 9 months after transplantation, no abnormalities were observed with the transplanted tooth in the radiographic and clinical evaluations.

Soft and hard tissue changes after bimaxillary surgery in Japanese class III asymmetric patients

Objectives: To assess the effects of bimaxillary surgery on Class III subjects with mandibular asymmetry, and to compare the effects of the type of surgery performed in the mandible on the facial profile especially in the presence of facial asymmetry. Materials and Methods: Thirty-six patients in whom imbalance between the maxilla and the mandible were corrected by Le Fort I osteotomy combined with bilateral intraoral vertical ramus osteotomy (BIVRO group, n=9), bilateral sagittal split ramus osteotomy (BSSRO group, n=14), or a combination of intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO) (IVRO + SSRO group, n=13). Cephalograms were taken before surgery (T1), and 1 year after surgery (T2). Hard and soft-tissue changes were compared. Results: The postsurgical findings showed that greater mandibular backward displacement and greater upper lip forward movement were more pronounced among BIVRO group when compared with BSSRO group. Upper lip relation to E-line showed greater improvement in BIVRO group than BSSRO and IVRO + SSRO groups. The ratios of corresponding mandibular soft to hard tissue movements were higher than that of maxillary movements and were more pronounced in IVRO + SSRO and BSSRO groups when compared with BIVRO group. Conclusion: IVRO surgical technique appears to be more effective in positioning the mandible more posteriorly and improving upper and lower lips position and competence.

Long-term observation of autotransplanted teeth with complete root formation in orthodontic patients

the medullary dorsal horn of rats was evaluated. Furthermore, to evaluate the nerve injury, we examined the distribution of protein gene product (PGP) 9.5-positive nerve fibers, which visualizes the entire tissue innervation, and the distribution of CGRPpositive nerve fibers, which are involved in periodontal tissue remodeling. Two hours after tooth movement, Fos-IR neurons in the ipsilateral part of the medullary dorsal horn increased significantly. CO2 laser irradiation to the gingiva just after tooth movement caused a significant decrease of Fos-IR neurons. PGP 9.5and CGRP-positive nerve fibers were observed in the PDL of all study groups. The maximum temperature below the mucosa during CO2 laser irradiation was less than 40 8C. It was suggested that CO2 laser irradiation reduced the early responses to nociceptive stimuli during tooth movement and might not have adverse effects on periodontal tissue.

Long-term changes in the occlusion post-retention on Japanese

Abstract Objective This study was designed to elucidate the changes in the occlusal condition over a long period of time post-retention in Japanese patients who had undergone extraction treatment with the standard edgewise system (SES), a method of treatment in which the intercanine width and intermolar width are kept unchanged in pre- and post-treatment. Materials and methods 21 patients were selected from the records of Niigata University Medical and Dental Hospital. These patients had undergone extraction treatment with SES, and their retainers were removed 5 or more years before. The study models were assessed pre-treatment (T1), post-treatment (T2), post-retention (T3), and more than 5 years post-retention (T4) to investigate overjet, overbite, intercanine and intermolar widths, total arch depth and the Irregularity Index (I.I.). Results and discussion The number of subjects in this study was larger than that in other long-term progress reports on Japanese patients post-retention. The interval between T3 and T4 was on average 8 years and 2 months. Both the mandibular I.I. and the maxillary I.I. became minimum values, suggesting that all the cases had been stable for a long period time post-retention. There were no significant changes in the intercanine width between T1 and T2, which means that the treatment had been performed based on a concept of minimizing any potential changes in intercanine width. Conclusion The treatment procedure of minimizing potential changes in intercanine width and aligning the teeth in consideration of individual alveolar morphology would contribute to long-term stability of occlusion after retention.

The relationship between objective evaluation by DAI and self-perceived dental aethetics in a population of university freshmen

month; eventually it had root fracture probably as a result of masticatory stress. The root-fractured tooth was immobilized with composite resin and orthodontic wire. The patient had a stable bite 6 years and 5 months after the fracture. A radiograph of the upper left-central incisor showed that the fractured site healed with interposition of bone and connective tissue. Also, the coronal fragment continued to erupt in concert with the growth of the alveolar process and helped to maintain the alveolar ridge of the same height and width as the adjacent teeth. These results indicated that ‘‘orthodontic traction of the inverted and impacted upper central incisor with a marked dilacerated root’’ was useful for maintaining the height and width of the alveolar ridge and would provide favorable conditions for replacing the retracted incisor with an implant or a bridge.