Mandibular Distraction and Orthognatic Surgery in Skeletal Class II Management – A Clinical Case

Introduction: A skeletal class II patient may present a mandibular retrognathia. This condition can lead to an inefficient breathing pattern, suboptimal mastication due to the improper occlusion pattern as well as an unsatisfactory profile. Although mandibular hypoplasia is a rather common occurrence, the combination of orthodontic and orthognathic procedures can be the most appropriate treatment for moderate to severe discrepancies. The lengthening of the mandible ramus can be achieved through a split ramus osteotomy or, in more severe cases, through a distraction device. This intervention can be chosen in order to achieve better aesthetics and function therefore improving the patient’s quality of life. The aim of this poster is to present a surgical-orthodontic approach for effective treatment of a skeletal class II associated with severe mandibular retrognathia.
Material and Methods: A twenty-three-year-old patient with severe skeletal class II presented to the Institute of Orthodontics looking for malocclusion correction. The patient had undergone previous orthodontic treatment at another centre, however she presented both breathing and feeding difficulties as well as unappealing facial aesthetics. After careful consideration of the initial case tooth-borne distraction osteogenesis for mandibular lengthening and surgical orthodontic treatment were suggested as the best treatment option.
Results: Roth 0,018 prescription fixed appliances were placed to level the arches followed by the placement of the tooth-borne distraction osteogenesis device which was activated twice bilaterally every 12 hours. At the end of the distraction, 11 mm of mandibular lengthening were obtained. After this intervention the orthodontic treatment progressed in order to prepare the patient for a orthognathic surgery of maxillary impaction and mandibular repositioning. A significant improvement in the ANB angle was achieved from 16º to 4º. Despite the facial soft tissue improvement, the convex profile still did not meet the patient’s aesthetic expectations so the patient was subsequently submitted to a genioplasty.
Discussion and Conclusions: The patient had re-established a functional occlusion, a more suitable breathing pattern, a desirable profile and an overall pleasant facial aesthetic.