Three-Dimensional Orofacial Changes Occurring After Proportional Condylectomy in Patients With Condylar Hyperplasia Type 1B (Unilateral Hemimandibular Elongation)

Purpose: To evaluate 3-dimensional orofacial changes that occurred after proportional condylectomy that was not followed by orthognathic surgery in patients with condylar hyperplasia type 1B (unilateral hemimandibular elongation). Materials and Methods: This retrospective analysis used the medical records of 14 skeletally mature patients. Transverse, vertical, and horizontal cephalometric analyses of photographs and radiographs were undertaken. A comparison of preoperative and postoperative measurements was conducted. Results: After proportional condylectomy, transverse chin position and vertical lip cant improved to various degrees, whereas ramus and condyle height and mandibular lower border discrepancy worsened to different extents. The prominence of the gonial angle of the affected (operated) side increased in all patients after surgery, and this contributed to better symmetry only when the preoperative prominence was small (flat), whereas the opposite occurred when the preoperative prominence was large (bulky). After condylectomy, there was posterior displacement of the pogonion point (setback), which was favorable in cases with a preoperative concave profile and unfavorable in cases with a preoperative convex profile. Conclusion: Proportional condylectomy can successfully arrest the hyperplastic growth of the affected condyle; however, it rarely achieves perfect symmetry of the face. Although it improves some facial features, other facial traits are worsened. Surgeons should have a full understanding of the 3-dimensional changes occurring after proportional condylectomy and should be able to predict, based on preoperative findings, the anticipated improvement or worsening of different facial features.