A mordida aberta anterior comumente está associada à mordida cruzada posterior. Há várias possibilidades terapêuticas para correção dessas deformidades, entre elas a ancoragem esquelética. Os aparelhos autoligáveis possibilitam a diminuição do atrito, facilitando a correção transversal por expansão da arcada superior. O presente artigo descreve o tratamento realizado em um paciente adulto, Face Longa, que apresentava uma má oclusão de Classe I de Angle, mordida cruzada posterior bilateral e mordida aberta anterior. Foi realizada a intrusão dos molares superiores, com ancoragem em miniplacas de titânio associadas ao aparelho autoligável SLI (Morelli Ortodontia, Sorocaba/SP, Brasil) com fios expandidos, para correção da mordida aberta anterior e adequação transversal, com acompanhamento da estabilidade do tratamento após três anos de controle. Os resultados sugeriram que as miniplacas promoveram pouca intrusão dos molares superiores e o fechamento da mordida se deu, em grande parte, pela extrusão dos dentes anteriores. Os braquetes autoligáveis associados a fios de CuNiTi expandidos promoveram uma expansão transversal limitada, sem a completa correção da mordida cruzada posterior. Ficou claro, no presente caso clínico, que essas mecânicas não foram as principais responsáveis ou, ainda, apresentaram limitações para a correção plena da má oclusão. Após três anos de controle, observou-se instabilidade dos resultados obtidos, ocorrendo uma discreta abertura da mordida anterior

The search for orthodontic treatment by adult patients has increased in the offices. Aesthetic demand is a contributing factor for this increase. When treating an adult patient, many types of occlusal problems can be found. As an example, we can mention the transverse deficiency of the maxilla. This clinical case is the compensatory treatment of a Pattern I patient with bilateral posterior crossbite, Class III molar relationship, upper arch atresia, and expansion of the lower arch. To perform the treatment self-ligating fixed appliance, Cooper NiTi wires with expanded diagram in the upper arch and conventional NiTi in the lower arch were used in conjunction with the bite lifters and the use of intermaxillary elastics (1/8 “) to uncross the bite. A satisfactory result was obtained by correcting the posterior crossbite ratio, obtaining a satisfactory Class I occlusion, improving the smile, overbite, and overjet within the standards, and resolving the patient’s complaint.

Objectives: This study aimed to evaluate the frictional resistance produced by active and passive self-ligating brackets on stainless steel archwires in the absence or presence of elastomeric chains under or over the wire. Materials and Methods: Four types of self-ligating brackets were used: Two active and two passive. For each commercial brand, five brackets were bonded to an acrylic plate and the frictional resistance was evaluated with 0.018” and 0.019” × 0.025” stainless steel wires in three situations: Without elastomeric chain, with elastomeric chain placed under and over the wire. Results: The bracket type, cross-section of the wire, and type of ligation had significant interactions with each other; the frictional resistance was significantly lower with the use of passive self-ligated brackets, while no difference was found when a 0.018” wire was tested. Moreover, the frictional resistance in the absence of an elastomeric chain, or when the chain was under the wire, was significantly lower in comparison with the values obtained when the chain was placed on the wire. Conclusion: Frictional resistance of passive and active self-ligated brackets is influenced by the ligation methods and the cross-sectioning of archwires.