Comparison of Bipartite Versus Tripartite Osteotomy for Maxillary Transversal Expansion Using 3-Dimensional Preoperative and Postexpansion Computed Tomography Data

摘要: Purpose: To evaluate tripartite paramedian versus bipartite median osteotomy in surgically assisted rapid maxillary expansion. Tripartite was performed between the lateral incisors and canines at former premaxillary junction to avoid midline diastema, septal columellar dislocation, asymmetric expansion, minimizing high-distraction forces through bilateral doubled on periodontia thus reducing vestibular attachment loss producing stable callus formation relapse. Patients Methods: The preoperative postexpansion computed tomography data from 50 patients were analyzed multiplanar viewing for bodily segment movement, bone loss, transverse skeletal dental widening with predefined landmarks. Of patients, 22 had undergone 28 osteotomy. Results: Using an independent t test, both osteotomies permitted adequate expansion premolars, converging, however, molars. Bipartite resulted less symmetry widening, greater movement first premolar/molar, loss. overall remodeling. On variance analysis, bone-borne distraction greatest decrease of older than 20 years. also provoked distractorand age-independent outward segmental movement. distractor- inward showed resorption younger years old molars premolars. Conclusions: allowed symmetric compared osteotomy, with, a decline posterior.