Finite element analysis of anterior maxillary segmental distraction osteogenesis using asymmetric distractors in patients with unilateral cleft lip and palate

Objective: The treatment of asymmetric maxillary hypoplasia and dental crowding secondary to unilateral cleft lip and palate (UCLP) is often challenging. This study introduced an asymmetric tooth-borne distractor in anterior maxillary segmental distraction osteogenesis and used three-dimensional finite element analysis to evaluate its potential for clinical application in cases of asymmetrical maxillary hypoplasia. Methods: A cone-beam computed tomography scan of a late adolescent with UCLP was used to construct a three-dimensional finite element model of the teeth and maxillary structures. An asymmetric distractor model was used to simulate conventional distraction osteogenesis and asymmetric distraction osteogenesis (ADO) to evaluate the resultant stress distribution and displacement. Results: Postoperatively, both distraction methods resulted in anterior maxillary segment advancement with a slight upward movement. ADO yielded a greater increase in the dental arch length on the cleft side and induced rotation of the anterior maxillary segment, potentially improving midline deviation. Both methods showed similar stress distributions, with higher stress concentrations on the cleft side. Conclusions: ADO may offer clinical advantages in correcting asymmetrical maxillary hypoplasia in patients with UCLP by facilitating asymmetrical expansion and rotation of the maxilla. Further research is needed to generalize these findings to other clinical presentations.