COMPARISON OF DIFFERENT MAXILLARY ADVANCEMENT PROTOCOLS IN PATIENTS WITH UNILATERAL CLEFT LIP AND PALATE: A FINITE ELEMENT ANALYSIS

Abstract

Abstract Objectives The aim of this study was to evaluate the stress distributions and possible amount of movement in the maxillofacial region resulted from different maxillary advancement protocols in patients with unilateral cleft lip and palate. Material and Methods A model with unilateral cleft lip and palate (CLP model) was created for finite element analysis. Three different protocols were compared: (1) usage of a face mask with elastics over a conventional acrylic plate; (2) usage of a face mask with elastics over miniplates placed in the infrazygomatic crest region; (3) usage of elastic from the menton plate placed in the mandible to the infrazygomatic plates in the maxilla. Results Dental effects were greater in the protocol with a face mask over a conventional acrylic plate, whereas skeletal effects were greater in maxillary protraction protocols using skeletal anchorage. The maximum amount of counterclockwise rotation of the maxilla was observed in traditional acrylic plate face mask protocol. Conclusions Skeletally anchored face mask caused more skeletal impact and displacement than other models. Clockwise rotation of the mandible was observed in the face mask model, while counterclockwise rotation was observed in the model with infrazygomatic plates and menton plate. Clinical relevance: When planning maxillary protraction treatment in patients with cleft lip and palate, it should be considered that more movement in the sagittal plane might be expected on the cleft side than the non-cleft side, and miniplate and screws on the cleft side are exposed to more stress when using infrazygomatic plates as skeletal anchorage.