Two-stage mandibular setback employing modified Dingman’s mandibular body osteotomy with step for large antero-posterior dentofacial deformity correction: a report of two cases

Mandibular prognathism is a well-known skeletal discrepancy with varying prevalence rates demographically. Patients with severe prognathism may experience difficulties speaking and chewing food as well as problems with psychosocial adjustment, indicating the need for surgical correction. In cases of single-stage larger mandibular setbacks, complications such as reduction in the pharyngeal airway and instability can be encountered. Therefore, two-stage orthognathic surgery could be recommended. Two patients (17-year-old female and 16-year-old female) reported with large mandibular antero-posterior discrepancies. Surgical correction was performed in two stages. In the first stage, a mandibular setback was performed with an anterior mandibular body osteotomy using Dingman's technique with a modified step osteotomy, as it provides an increased surface area of contact between the osteotomized segments to achieve better stability. Osteofixation was done using locking titanium miniplates. A year after orthodontic decompensation at the second stage, maxillary advancement using Le Fort I osteotomy and bilateral sagittal split osteotomy for mandibular setback were performed and fixed with unsintered hydroxyapatite/poly-L-lactic acid plates and screws. The post-operative course was followed by post-surgical orthodontics. It can be concluded that a harmonized facial profile with good outcome in terms of skeletal stability, airway dimensions and occlusion were achieved with patient satisfaction.