The Efficiency of Segmental Le Fort I Surgery in Clear Aligner Therapy of Skeletal Class III Deformity: A Pilot Study.

INTRODUCTION: The purpose of this study was to investigate the efficiency of segmental Le Fort I osteotomy in clear aligner therapy of skeletal Class III deformities and to explore whether Le Fort I segmental osteotomy was effective for maxillary incisor axis correction and reduced the duration of perioperative orthodontics. MATERIALS AND METHODS: Patients who had skeletal Class III deformities (ANB<0) treated with extraction of the maxillary first premolars, segmental Le Fort I osteotomy, and clear aligners therapy were included in this retrospective study. We measured the amount of tooth extraction space that was closed by surgery and recorded the preoperative orthodontic and total treatment duration. Lateral cephalograms were analyzed to measure changes of maxillary incisor inclination before treatment (T0), 1 week before surgery (T1), 1 week after surgery (T2), and after total orthodontic treatment (T3). Statistical analyses were performed, and the P value was set at 0.05. RESULTS: The sample was composed of 15 patients aged 19 to 30 (M=22.9) years. The average preoperative orthodontic treatment duration was 16.2±5.22 mo, with 33.5 pairs of clear aligners. The gap at the extraction site decreased from 5.42±1.57 mm to 0.80±0.62 mm on average after surgery. U1-SN and U1-NA(deg) increased sparingly with preoperative decompensation, decreased in quantity after surgery, and then slightly increased with postoperative compensation (T20.05). CONCLUSIONS: Le Fort I segmental osteotomy assisted decompensation of the upper anterior teeth and reduced the duration of preoperative orthodontics with clear aligners.

MSCT 3D Analysis of Nasopharyngeal Airway After Le Fort I Maxillary Setback Surgeries.

In recent years, maxillary Le Fort I osteotomy setback has been widely applied in correcting maxilla prognathism. In the meantime, airway considerations have attracted more and more attention. The aim of this research was to observe the alteration of nasopharyngeal airway indexes after maxilla setback and offer evidence for the effectiveness and safety of maxillary Le Fort I setback surgeries. As for a retrospective cross-sectional study, 40 patients diagnosed with maxilla prognathism and undergoing maxillary setback surgeries were enrolled. They were grouped by the type of maxillary setback operations as group A (integral maxillary setback, n=19) and group B (segmental maxillary setback, n=21). Multislice computed tomography data were collected 1 week before (T0) and more than 3 months (T1) after surgery. 3D reconstruction and evaluation of the pharyngeal airway were conducted to analyze nasopharyngeal airway index variation before and after surgery and the difference between group A and group B. Preoperative and postoperative nasopharyngeal airway volume showed no statistical significance in group A (P=0.872) and group B (P=0.169) as well as other indexes of the nasopharynx. The comparison of postoperative airway changes between group A and group B also showed no significant difference. Both integral and segmental maxillary Le Fort I osteotomy setbacks have slight impact on nasopharyngeal airway dimensions and are safe within a specific setback range.

Surgical Precision Analysis of Orthognathic Surgery Combined With Invisible Orthodontic.

BACKGROUND: This study aimed to explore the changes in hard tissue after applying invisible orthodontic-orthognathic treatment and the digital design, and to explore the accuracy of the treatment effect of maxillofacial tissue after invisible orthodontic treatment and orthognathic treatment. METHODS: From September 2020 to January 2022, 25 patients with class III skeletal malocclusion and 7 patients with class II skeletal malocclusion, were treated with invisible orthodontic treatment and orthognathic combined treatment. Orthodontic treatment with preoperative invisible orthodontic treatment followed by orthodontic surgery. All patients had cephalometric lateral films after surgery to analyze orthognathic surgery's goals and surgical effects of orthognathic surgery and the digital design. Measure the angle of the sella-nasion-A point angle, angle of sella-nasion-B point, ANB angle, maxillary convex angle, mandibular plane (MP) angle, 1-SN angle, 1-MP angle, etc, and compare surgery outcome with digital design. RESULT: All patients were satisfied with the effect and no complications occurred. Angle of sella-nasion-A point, angle of sella-nasion-B point, ANB angle, maxillary convex angle, MP angle, 1-SN angle, and 1-MP angle had no significant difference between the postoperative effect and the purpose of digital design ( P >0.05), there was no apparent deviation between the upper and lower jaw and the chin ( P >0.05). CONCLUSION: The combined invisible orthodontic treatment and orthognathic treatment are accurate and effective, and are worthy of promotion. It supplements traditional orthognathic therapy and is suitable for corresponding patients.

Evaluation of mandibular setback after bilateral sagittal split osteotomy with the hunsuck modification and miniplate fixation.

PURPOSE: This study was conducted to evaluate neurosensory disturbances (NSDs) and jaw movement after bilateral sagittal split osteotomy (BSSO) with the Hunsuck modification and miniplate fixation to correct mandibular prognathism. PATIENTS AND METHODS: A total of 63 patients who underwent Hunsuck-modified BSSO to correct mandibular prognathism were studied. Both 3-month and 6-month postoperative Schuller's temporomandibular joint (TMJ) views tracing the 63 patients were studied to analyze mandibular movement. The patients' NSD and TMJ symptoms were recorded. Data were analyzed using 1-way analysis of variance. RESULTS: The mean TMJ was 9.6% with clicking before surgery. At the evaluation 6 months after surgery, the clicking had reduced to 3.1%. The lip neuorsensory deficit increased to 23.8% at 6 months after surgery. The jaw position measurements before and after surgery showed statistically significant differences in mouth opening and jaw advancement (P < .05). The changes in mandibular lateral movement were not statistically significant (P > .05). CONCLUSIONS: The results of this study show reduced TMJ clicking, the presence of NSDs, and reduced mouth opening after Hunsuck-modified BSSO.

Clinical application of indirect bonding / 实用口腔医学杂志

Objective:To investigate the clinical application of indirect-bonding in orthodontics. Methods:An ordinary Chinese paste was used to bond bracket on hard plaster stone, then tranfer it to elastic plastic film. Clinic bonding could use chemical curing or light curing adhesive. Results:Twenty patients were treated with indirect bonding method. Most patients reported that the bonding is much more comfortable and less time-consuming than anticipated. Conclusion:Indirect-bonding method could be a good supplement for direct bonding method.