Pre-maxillary complex morphology in bilateral cleft and hypothesis on laterality of deviated pre-maxilla

INTRODUCTION Pre-maxillary complex (pre-maxilla [PMX] + vomer) morphology in bilateral complete cleft of primary and secondary palate (BCLCP) is very complex and less reviewed in literature. MATERIALS AND METHODS In this retrospective cross-sectional study, 200 consecutive BCLCP patients were selected. Their pre-operative clinical photographs and dental casts were evaluated by a single investigator at two different points of time, to study the morphology of PMX and vomer with special emphasis on deviation of vomer and rotation of PMX. RESULTS It is found that in above 70% of patients, PMX and vomer both displaced or deviated towards left side in horizontal plane and PMX rotated anticlockwise at PMX vomerine suture (PVS). In 10% of cases, both PMX and vomer are displaced towards the right side, PMX rotated clockwise at PVS. In 11% of cases, vomer is displaced towards the left side, but PMX rotated clockwise at PVS. In 5% of cases, vomer is displaced towards the right side, but PMX rotated anticlockwise at PVS. Both PMX and vomer are in midline in 4% of cases. CONCLUSION Specific morphological deviation of vomer and PMX has been studied. We put forward the probable hypothesis to explain the deviation and rotation of PMX.