Distalisation of maxillary molars using direct skeletal anchor devices in patients with Class II malocclusions. Literature review

Abstract

Introduction: The Angle Class II molar ratio is approximately 20% of the population. When malocclusion is of dental origin, mainly generated by a migration of lateral segments, the most frequent treatment option to generate space and to establish a Class I molar relationship is molar distalization. A large number of treatment devices and protocols have been described in the literature. One of the most used is the Pendulum, but because of its design that uses dental anchorage and its force happens at the level of the crown of the first molars, presents many disadvantages. Objective: The purpose of this review is to analyze molar distalization devices using direct skeletal anchors, in which the applied force passes near the center of resistance of the upper first molar, in order to determine if they are superior in efficiency and minimization of adverse effects when compared with conventional appliances. Results: The search process included a total of 25 articles selected based on year of publication and use of skeletal anchorage, 7 articles were finally used for review, based on inclusion and exclusion criteria. Discussion: When comparing the devices, there is great variability in duration of treatment, amount of distalization and rate of distalization. In spite of these differences all showed clinical success to finalize the mechanics of distalization. On the other hand, there is a spontaneous distalization of the second upper premolars and even the first premolars with these devices that do not use these dental pieces as an anchorage, therefore, they remain free and are distalized with the help of the transseptal fibers. Conclusion: It is concluded that molar distalization has proved to be an effective procedure when using devices with direct skeletal anchors and with a force vector passing close to the resistance center of the first molars. These methods do not generate side effects in the anchoring region when compared to conventional apparatus where there is mesial migration of premolars and anterior parts. In all the cases analyzed, the maxillary molars were distalized to a class I relationship in a short period of time, even in spite of the presence of the second and third maxillary molars.