Part 2: Is the maxillary canting and its surgical correction in patients with CFM correlated to the mandibular deformity?

INTRODUCTION: Patients with Craniofacial Microsomia (CFM) mandibles Types I/IIa benefit from combined LeFort 1 osteotomy and Mandibular Distraction Osteogenesis (LeFort + MDO); Type IIb from LeFort + MDO or Bimaxillary osteotomy (BiMax); and Type III from BiMax (with 50% of cases having preceding mandibular procedures, including patient-fitted prosthesis); as seen in Part 1. This leads to the question how maxillary and mandibular hypoplasia are correlated and influence the types of maxillary correction.

MATERIAL AND METHODS: A retrospective chart study was conducted including patients diagnosed with CFM from 2 large craniofacial units. Radiographic and clinical information were obtained. Unilateral affected patients with available (ConeBeam) CT-scan of the maxillary-mandibular complex, without treatment of the upper jaw prior to the CT-scan were included. A maxillary cant grading system was set up and evaluated. Pearson correlation coefficients were used to correlate the maxillary cant and the severity of the mandibular hypoplasia.

RESULTS: Eighty-one patients were included, of whom 39.5% had a Pruzansky-Kaban type III mandible and 42% a mild maxillary cant. There was a significant positive correlation between severity of the mandibular hypoplasia and the categorized canting (r = 0.370; p < 0.001; n = 81). Twenty-four patients had maxillary surgery, mainly a BiMax.

CONCLUSION: There is a positive correlation between the severity of mandibular hypoplasia and maxillary cant. The severity of mandibular hypoplasia seems to dictate an intervention for both maxillary and mandibular surgery.