Single-Splint, 2-Jaw Orthognathic Surgery for Correction of Facial Asymmetry: 3-Dimensional Planning and Surgical Execution.

Three-dimensional (3D) planning of orthognathic surgery (OGS) improves the treatment of facial asymmetry and malocclusion, but no consensus exists among clinicians regarding technical details. This study verified the consistency of authors' workflow and strategies between 3D planning and surgical execution for facial asymmetry. This retrospective study recruited consecutive patients (n=54) with nonsyndromic facial asymmetry associated with malocclusion. The stepwise workflow included orthodontic treatment, 3D imaging-based evaluation, planning, and transferring the virtual of single-splint 2-jaw OGS to actual surgery in all patients. Seven landmark-based measurements were selected for postoperative assessment of facial symmetry. Fifty patients had no anesthetic/surgical-related episode and procedure-related complications. Others experienced wound infection (n=1), transient TMJ discomfort (n=1), and facial numbness (n=3). Two cases had minor residual asymmetry (cheek and chin, respectively), but did not request revisionary bone or soft tissue surgery. Comparisons between the planned and postoperative 3D images with quantitative measurement revealed acceptable outcome data. The results showed a significant increase in facial symmetry at 7 landmark-based postoperative measurements for both male and female. This 3D-assisted pathway of OGS permitted achievement of consistent satisfactory results in managing facial asymmetry, with low rate of complications and secondary management.

Avoiding Inferior Alveolar Nerve Injury during Osseous Genioplasty: A Guide for the Safe Zone by Three-Dimensional Virtual Imaging.

BACKGROUND: No consensus exists about the safest position for performing the osseous genioplasty, with 5 to 6 mm below the mental foramen being the most frequently recommended position. This study intends to generate a safe distance guide to minimize the risk of inferior alveolar nerve injury during osteotomy. METHODS: Pretreatment cone-beam computed tomography-derived three-dimensional models from adult patients with skeletal class I to III patterns and cleft lip/palate deformity who underwent orthodontic-surgical interventions (n = 317) were analyzed. A three-dimensional vertical distance between the inferior margin of the mental foramen and the lowest point of the inferior alveolar nerve canal was measured in each three-dimensional hemimandible (n = 634). Statistical analysis was performed to generate the safe distance guide in a stepwise fashion at 95, 99, and 99.99 percent confidence levels. RESULTS: Class III (4.35 ± 1.42 mm) and cleft lip/palate (4.42 ± 1.53 mm) groups presented significantly (p < 0.001) larger three-dimensional distances than class I (3.44 ± 1.54 mm) and class II (3.66 ± 1.51 mm) groups. By considering the 5- to 6-mm safe distance parameter, 6.4, 5.0, 10.6, 16, and 9.9 percent of hemimandibles were at risk of osteotomy-induced nerve injury in the class I, class II, class III, cleft lip/palate, and overall cohorts, respectively. Overall, the safe distance zone to perform the osteotomy was set at 7.06, 8.01, and 9.12 mm below the mental foramen, with risk probabilities of 2.5, 0.5, and 0.0005 percent, respectively. CONCLUSION: This study contributes to patient safety and surgeon practice by proving a safe distance guide for genioplasty.

Outcome of Patients with Complete Unilateral Cleft Lip and Palate: 20-Year Follow-Up of a Treatment Protocol.

BACKGROUND: The treatment plan for cleft lip and palate varies among centers and requires long-term evaluation of its final outcome. METHODS: A consecutive series of patients born from 1994 to 1996 were reviewed. Inclusion criteria were complete unilateral cleft lip and palate, undergoing all treatment procedures performed by the team, and continuous follow-ups until 20 years of age. Exclusion criteria were incomplete data, having microform cleft lip on the contralateral side, presence of the Simonart band, and other abnormalities. RESULTS: A total of 72 patients were included. Average age at final evaluation was 21.3 years; 83.3 percent of patients underwent one-stage rotation-advancement lip repair and 16.7 percent underwent two-stage repair with an initial adhesion cheiloplasty. All patients underwent palate repair using the two-flap method at an average age of 12.3 months. Velopharyngeal insufficiency occurred and required surgical interventions in 19.4 percent during the preschool age and in 16.7 percent at the time of alveolar bone grafting; 56.9 percent of patients underwent secondary lip/nose revision during the growing age. Regular orthodontic treatment was administered to 34.7 percent of patients between 12 and 16 years of age. Orthodontic treatment and orthognathic surgery were applied in 37.5 percent of the patients after maturity. The average number of surgical procedures to complete the treatment was 4.8 per patient. CONCLUSIONS: This treatment protocol provided generally acceptable final outcome after the 20-year follow-up. Some results were less ideal and have resulted in modifications of the planning and methods in the protocol. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.