Micro-osteoperforations in the aligner treatment of hyperdivergent Class II patients

Hyperdivergent Class II malocclusion is one of the most challenging types of malocclusions to treat using fixed appliances because distalisation is not recommended, so the possible options are extraction treatment or careful vertical correction. Clear aligners can be a useful option for treating hyperdivergent Class II patients without the need for extraction because they offer efficient control of the undesired extrusion during distalisation as molar intrusion can be planned and performed to control vertical excess. In many cases, treatment of vertical Class II malocclusion should involve a combination of transverse, vertical and sagittal correction. The present case report illustrates the orthodontic treatment for a hyperdivergent Class II adult patient in which distalisation and transverse and vertical correction were simplified by means of micro-osteoperforations performed selectively, beginning in the posterior region before progressing to the lateral sectors and then the anterior teeth to stimulate the bone in specific areas according to the movement sequence, thus reducing the need for patient compliance in using elastics for anchorage. The digital setup (ClinCheck, Align Technology, San Jose, CA, USA) was designed to enable sequential distalisation, expansion and molar intrusion to occur simultaneously. Distalisation was combined with anterior extrusion following smile arc exposure, and the treatment was completed over a period of 12 months.The present alternative for the treatment of hyperdivergent Class II malocclusion, i.e., combining selective micro-osteoperforations in the posterior and anterior regions with clear aligners, appears to increase the predictability of molar vertical control when performed simultaneously to expansion and distalisation and to induce a counterclockwise rotation of the mandible. Arch development, molar distalisation and intrusion with consequent mandibular rotation can be achieved predictably in a way that respects the digital setup and that creates a proper Class I bilateral occlusion, thus reducing the need for patient compliance in using maxillomandibular elastics for anchorage since the anchorage is modulated by selective micro-osteoperforations and a consequent regional acceleratory phenomenon. Keywords: aligners, micro-osteoperforations, open bite