Aligner use for dento-alveolar open bite treatment in adult patients. a review

Aim: Vertical control is one of the most important phases during orthodontic treatments. Such control needs increased attention during open bite (OB) treatment. Open bite is a vertical alteration of normal occlusion, characterized by anterior or posterior space between the teeth, during occlusion contact. Many causes can lead to open bite malocclusion, like bad habits, or genetic/familial factors. Open bite malocclusion is classified in skeletal open bite, dentoalveolar open bite or combined form. A proper diagnosis guided the treatment. Surgical treatment is more indicated for a skeletal open bite; instead, dental open bite can be treated with a combination of anterior teeth extrusion and, posterior teeth intrusion. Traditionally multibracket therapy is the first choice to treat dentoalveolar OB in adult patients. A new therapeutic option is the aligner treatment. Today, aligners could be used in more complex cases, like open bite treatment. The aim of this review is to estimate the efficiency of aligner treatment in dento-alveolar open bite adult patients. Methods: A research was made on PubMed and Cochrane with the following keyword: “Open Bite” and “Aligner”). In addition, we made a hand search on relevant citations and references found in the selected articles. The following inclusions criteria were used to select appropriate articles: patient’s age between 20 to 40 years, articles written in English, studies from January 2000 to December 2018. We excluded studies on syndromic patients and patients with a skeletal OB. The researchers identified 20 titles, of which 14 were excluded at the first stage, according to the exclusion criteria. The remaining 6 articles fulfilled the initial inclusion criteria, was read in full text. Results: Many studies show that new aligner’s material, the introduction of optimate attachment and interarch elastics get the aligners more efficient. Overbite is more controlled during aligner treatment, thank to occlusal appliance thickness, that in addition to biting force transmitted an intrusive action on the posterior teeth. Many studies show that the aligner doesn’t have good control on teeth extrusion, because appliance cannot get a sufficient force. Guarnieri et al. have added attachment on upper and lower incisors to increase appliance extrusive force. One of the Main contraindication on aligner treatment is an overbite higher than 2mm. Multibracket appliance leads to an incisors proinclination, that in addition to elastic use can produce an Open bite, caused by a posterior teeth extrusion. That is an unexpected consequence during an open bite treatment. During the Aligner treatment, the teeth are blocked together by the alliance, which produces less unexpected effects than multibracket treatment. OB can be treated with aligners with a combination of upper and lower incisors retro-inclination and intrusion and better vertical control without a posterior teeth extrusion. Studies show that no difference was found on occlusal stability and long-term relapse on Open Bite treat by the fixed appliance and by aligners. Conclusion: More studies have to be made to support aligner use as alternative to the fixed appliance to treat complex malocclusion ad OB. Some studies says that aligner use on OB treatment is not recommended, but there are a lot of case report that show it is possible to treat OB in adults patients. New aligner material and auxilia use (as inter-arch elastics or bite ramps) seems to allow more predicable treatments. Often the studies in literature are case report and presente much bias as poor number of patients, so we don’t have scientific supported results. Adult patients have esthetic needs, so often it’s required an invisible treatment. So it’s cold be an interesting field for future studies