Hard and soft tissue changes after Lefort1 osteotomy and mandibular autorotation

Abstract

OBJECTIVES: Prediction of soft tissue changes following orthogenetic surgery has always beenchallenging for orthodontists and surgeons. There is a plethora of literature on the subject of soft tissuechanges associated with orthogenetic surgery, but it has remained as a matter of controversial. The aimof this study was to evaluate soft and hard tissue changes in vertical and anterior posterior dimensionfollowing Lefort I surgery.METHODS AND MATERIALS: 15 patients (12 females and 3 males) having Cl II Div 1 malocclusionwith open bite more than 4 mm were selected. Following the arch coordination and arch decompensation,patients underwent Lefort 1 surgery. Preoperatively, the study casts, panoramic view, and lateralcephalometry were prepared.RESULTS: The angle of Go.GN/S.N and Y axis followed a significant reduction trend after the surgeryfrom 41/4 ± 7/3° to 34/4 ± 7/8° (P0/001) and from 69/4 ± 3/8 ° to 66/1 ± 4/6° (P<0/009), respectively. Inthe vertical dimension (related to the Y axis), the following parameters reduced significantly after theorthognathic surgery: L1, B, Pog, Me, PNS. Whereas, in the anterior – posterior dimension (related to theX axis), only the interval of the tip of the mesiobuccal cusp of the maxillary first molar in relative of the Xaxis modified in significant way (P<0/01).CONCLUSION: In posterior impaction of maxilla, the anterior facial height was significantly reducedand hard and soft tissue cephalometric landmarks of the mandible reduced in the vertical dimension.Lower lip length significantly reduced. Upper lip length and protrusion changed postoperatively but it wasnot statistically significant.