What Is the Accuracy of Bimaxillary Orthognathic Surgery Using Occlusally-Based Guides and Patient-Specific Fixation in Both Jaws? A Cohort Study and Discussion of Surgical Techniques.

PURPOSE: The development of advanced digital orthognathic surgical protocols requires investigation to determine the accuracy of surgical outcomes. This report's purpose is to quantify 3-dimensional linear discrepancies between simulated and actual results for double-jaw orthognathic surgery utilizing occlusally-based guides in conjunction with patient-specific fixation in both jaws. METHODS: This retrospective cohort study assessed the accuracy of double-jaw orthognathic surgery, in all cases performed by 1 surgeon between May 2019 and January 2021, utilizing occlusally-based guides and patient-specific fixation plates in both maxillary and mandibular surgeries. The primary outcome was absolute linear discrepancy between virtually-planned and surgically-achieved maxillary and mandibular position in 3 dimensions. Secondary outcomes were relative (directional) discrepancy, to assess if protocols erred in 1 direction of each surgical axis. Sequencing of bimaxillary surgery, age, and sex were covariates. Absolute and relative linear differences at A-point, B-point, and pogonion were evaluated using t tests. Descriptive statistics were amassed, and results were analyzed to determine if discrepancies differed from a null hypothesis of 2-mm error. RESULTS: Forty-nine patients were enrolled, consisting of 25 males and 24 females with a mean age of 24.8 years. Thirty-five single-piece and 14 multipiece LeFort I osteotomies, 49 bilateral sagittal splits, and 35 genioplasties were studied; there were 22 maxilla-first and 27 mandible-first surgeries. Mean A-point absolute discrepancies of 0.57 (95% confidence interval: 0.41-0.73), 0.37 (0.24-0.50), and 0.45 (0.33-0.57) mm were observed in horizontal, transverse, and vertical planes, respectively. B-point discrepancies were 1.15 (0.79-1.52), 0.62 (0.47-0.78), and 1.14 (0.91-1.38) mm. Pogonion discrepancies were 1.29 (0.86-1.73), 0.85 (0.64-1.06), and 1.24 (1.00-1.49) mm. All P values were <.001. Sequencing of bimaxillary surgery did not alter absolute differences (P = .2 to >.9) with A-point discrepancies consistently smaller than B-point and pogonion discrepancies regardless of sequencing. Mandible-first surgery was associated with posterior directional error; both sequences were associated with superior directional error at B-point and pogonion. CONCLUSION: Bimaxillary orthognathic surgery utilizing a patient-specific protocol in both jaws produces results highly reproducible to planned simulated surgery and accurate below a 2-mm hypothesis, with maxillary discrepancies approaching 0.5 mm and mandibular discrepancies approaching 1 mm.

Low-Intensity Pulsed Ultrasound Therapy: A Nonsurgical Treatment Modality for Mandible Fracture Nonunion?

Standard treatment of mandibular nonunion includes debridement and application of maxillomandibular or rigid internal fixation techniques, with adjunctive bone grafting when necessary. Frequently described in the orthopaedic literature, low-intensity pulsed ultrasound therapy (LIPUS) is a noninvasive treatment modality used to accelerate healing of fresh fractures and established nonunions. The purpose of this study was to conduct a systematic review to determine the extent of LIPUS study in the treatment of mandibular nonunions to identify whether LIPUS represents an effective nonsurgical alternative or adjunct for nonunion management. A literature review was conducted to investigate published reports on the utilization of LIPUS in treating mandible fracture nonunions. The search yielded two randomized controlled trials demonstrating favorable healing parameters in fresh human mandible fractures treated with LIPUS, two randomized controlled trials demonstrating osteogenic differentiation in human mandibular fracture cellular components, and one study reporting improved healing at rabbit mandibular osteotomy sites. No articles published reports studying LIPUS in facial fracture nonunion were identified. This report reviews published literature on mandibular nonunions, and the evidence of LIPUS use in long bone nonunions. There are no known studies presenting LIPUS treatment of mandible fracture nonunions. However, on the basis of published orthopaedic data, LIPUS therapy could be considered as an adjunct or alternative to traditional surgical management of select mandible fracture nonunions.