Chin Wing Osteotomy for Improving Mandible Projection and Contour in Patients with Normal Occlusion: Case Reports.

Aim: To present a chin wing osteotomy in two patients who had undergone a virtual surgical planning workflow for surgical procedures and were followed up for 4 years. Case reports: Two retrognathic patients with normal occlusion were evaluated by means of dental and facial photographs, cone beam computed tomographs and digitization of dental arches. Virtual surgical planning was performed by using the Dolphin Imaging software to simulate the chin wing osteotomy. Next, three-dimensional models were imported into computer-aided design system (Rhino 6) for designing two hybrid (dental-bone supported) cutting and repositioning guides. Chin wing osteotomies were carried out by using the cutting guides and the osteotomized segments were placed by using L-shaped plates and screws assisted by the repositioning guides. Bone grafts were interposed in the mandibular angle region bilaterally. In both cases, the patients reported aesthetically and functionally favorable outcomes. Conclusion: Chin wing osteotomy is an appropriate treatment for retrognathic mandible in patients with normal occlusion and no additional discrepancies as the technique provided chin advancement and improvement in facial contour. The post-operative outcomes showed reliable workflow of virtual planning and surgical procedures, which could be adopted as an alternative in similar cases.

Force systems yielded by different designs of T-loop.

OBJECTIVES: To determine the mechanical characteristics of beta-titanium T-loops with and without helices, with 0 and 180 degree gable bends and constructed from 0.017 inch x 0.025 inch and 0.019 inch x 0.025 inch wire. METHODS: Forty beta-titanium T-loops were centrally positioned in a universal testing machine. The horizontal force and the moment/force ratios during activation were recorded at 1 mm intervals, up to a maximum of 7 mm. The data were analysed with analysis of variance complemented by the Tukey test for multiple comparisons. RESULTS: The results demonstrated that the transverse section of the wire had the greatest effect on the horizontal force produced by the loops. Significantly lower levels of horizontal force were obtained with loops made with the smaller 0.017 inch x 0.025 inch wire. Loops with gable bends yielded high moment/force ratios, whereas loops without gable bends had low moment/force ratios. In general, T-loops with helices yielded lower magnitudes of horizontal force and moment/force ratios than plain T-loops. CONCLUSIONS: The horizontal forces and moment/force ratios generated by plain T-loops with 180 degree gable bends yielded more adequate force systems. Incorporation of helices in the design of T-loops seems to be unnecessary.

Maxillary first permanent molar impaction. A conservative treatment approach.

The objective of this clinical case is to suggest a treatment approach for impaction of the maxillary first permanent molars. This approach allows access to the partially erupted tooth for orthodontic bonding and utilization of loops for distalization. An important detail is the non inclusion of the primary second molar in the orthodontic mechanics, in order to reduce the risk of early loss and preserve this tooth until exfoliation.

Evaluation of the influence of dental bleaching with 35% hydrogen peroxide in orthodontic bracket shear bond strength.

OBJECTIVE: The purpose of this study was to evaluate, in vitro, the bond strength of brackets bonded to premolars previously subjected to bleaching with a 35% hydrogen peroxide. METHODS: Twenty one healthy premolars were selected and randomly divided into three groups (n = 7). Group I (G1) included teeth that were not submitted to bleaching. The enamel surfaces of Groups II (G2) and III (G3) were submitted to a bleaching process with 35% hydrogen peroxide (Whiteness HP Maxx). On Group II (G2), after bleaching, the teeth were stored for 24 hours in distilled water at 98.6 °F, and then, premolar metallic brackets were bonded using Transbond XT (3M) resin. Group III (G3) was submitted to the same procedure seven days after bleaching. After bonding, all teeth were stored in distilled water at 98.6 °F for 24 hours. All groups were submitted to a traction test using an EMIC DL2000 universal testing machine at a speed of 0.5 mm/min. RESULTS AND CONCLUSION: The bracket resistance to debonding was compared between the groups by the Kruskal-Wallis nonparametric test (p < 0.05) and it was verified that the bleaching agent significantly reduced bracket adhesion when bonded 24 hours after bleaching. However, seven days after bleaching, there was no significant difference on the resistance to debonding among groups G1 (19,52 kgf) and G3 (18,44 kgf), meaning that it is necessary to wait longer after bleaching to bond brackets.

Occlusal assessment in surgically assisted unilateral cleft lip and palate patients.

OBJECTIVE: The aim of this study was to assess the magnitude of occlusal changes in individuals with unilateral cleft lip and palate (CLP). The study was conducted on study cast models of 25 subjects, 14 men and 11 women aged from 7 to 20 years, without previous orthodontic treatment and with surgical repair carried out at São Marcos Hospital, Teresina, Piauí State, Brazil. METHODS: The cast models were assessed by three orthodontists based on the occlusal scores established by Atack et al., whose scores range from 1 to 5, according to the magnitude of transverse and sagittal changes. RESULTS: Intra and inter-observer reproducibility of occlusal scores was satisfactory and statistically significant according to the Spearman correlation test with significance level set at 5%. With regard to the distribution of occlusal scores, 30.67% of the subjects achieved scores 1 and 2, 22% score 3 and 47.53% achieved scores 4 and 5. CONCLUSIONS: Four was the score most frequently assigned by the observers, disclosing a high degree of transverse and sagittal disorders in the occlusion of patients.

A case report palatal implant for molar distalization

Implants obtained popularity in Orthodontics by to make easy the maximum anchorage with the minimal patient׳s compliance. In this context, osseointegrated implants has been frequently used as auxiliaries of orthodontic treatments, substituting in some cases inter maxillaries elastics and extra oral appliances. These implants show as advantage a independence in opposite the patient׳s compliance, the anchorage possibility in periodontal loss cases, over there an esthetic improvement and the comfort propitiated, showing more expected results. This article approach the orthodontic treatment of a clinic case of Class II, division 1 malocclusion, non-extraction accomplished and with palatal implant to distalization of latter teeth.