Impact of general anesthesia on postoperative complications in orthognathic surgery: a retrospective comparison of total intravenous anesthesia versus volatile anesthesia.

Orthognathic surgery has a high incidence of postoperative nausea (PON) and vomiting (POV), delaying mobility initiation and postoperative recovery. Bleeding is another risk associated with this surgical procedure. We aimed to compare total intravenous anesthesia (TIVA) and volatile anesthesia in patients undergoing orthognathic surgery in terms of postoperative nausea and vomiting (PONV) incidence and hemodynamic changes. This retrospective study included 82 patients who underwent bilateral sagittal split ramus osteotomies at Saga University Hospital between April 2016 and April 2021. We compared the effects of TIVA and volatile anesthesia on PONV onset after surgery, acute postoperative hemodynamic changes (blood pressure and heart rate), and factors contributing to PONV. PON was significantly lower in the TIVA group than in the volatile anesthesia group. The total dose of fentanyl contributed to the onset of POV, while the onset of PON was associated with low volumes of fluid infusion and urine in the TIVA and volatile anesthesia groups, respectively. Furthermore, post-extubation hemodynamic change was significantly smaller in the TIVA group than in the volatile anesthesia group. Therefore, TIVA could have a reduced risk of PONV and hemodynamic changes in patients undergoing orthognathic surgery. Employing TIVA could mitigate perioperative complications and enhance patient safety.

3D evaluation model of facial aesthetics based on multi-input 3D convolution neural networks for orthognathic surgery.

BACKGROUND: Quantitative evaluation of facial aesthetics is an important but also time-consuming procedure in orthognathic surgery, while existing 2D beauty-scoring models are mainly used for entertainment with less clinical impact. METHODS: A deep-learning-based 3D evaluation model DeepBeauty3D was designed and trained using 133 patients' CT images. The customised image preprocessing module extracted the skeleton, soft tissue, and personal physical information from raw DICOM data, and the predicting network module employed 3-input-2-output convolution neural networks (CNN) to receive the aforementioned data and output aesthetic scores automatically. RESULTS: Experiment results showed that this model predicted the skeleton and soft tissue score with 0.231 ± 0.218 (4.62%) and 0.100 ± 0.344 (2.00%) accuracy in 11.203 ± 2.824 s from raw CT images. CONCLUSION: This study provided an end-to-end solution using real clinical data based on 3D CNN to quantitatively evaluate facial aesthetics by considering three anatomical factors simultaneously, showing promising potential in reducing workload and bridging the surgeon-patient aesthetics perspective gap.

Bone microstructural characteristics or positional changes of condyle head affect short-term condyle head resorption after orthognathic surgery.

Condylar resorption occurs in some cases after orthognathic surgery, and the risk factors associated with postoperative condylar head resorption have been extensively described. Nevertheless, even in cases with a combination of risk factors, postoperative condylar resorption may not appear. This study analyzed the microstructure and three-dimensional positional change of the condylar bone via imaging in patients who have undergone bimaxillary orthognathic surgery to determine whether the microstructure or condylar position differs between patients with and without postoperative condylar resorption. Among asymptomatic patients who underwent bimaxillary surgery between April 2021 and March 2022 at our department, 17 patients were analyzed, limited to "female," "skeletal Class II," and "high-angle cases," which are known risk factors for mandibular head resorption. Multidetector computed tomography was performed on these patients before and 6 months after surgery, and the bone microstructure of the condylar head and the three-dimensional positional changes of the condylar bone and the proximal bony fragments were compared with the presence of postoperative condyle resorption using the bone morphology software TRI/3D-BON. Patients with condylar bone abnormalities before surgery and those with high trabecular bone density can develop postoperative resorption if the condyle is misaligned by surgery.

Kern's six-step approach allows for meaningful implementation of an orthognathic surgery training course.

OBJECTIVES: This study investigated the effectiveness of simulation training in improving the confidence and competency of oral and maxillofacial surgery (OMS) residents in performing orthognathic surgery (OGS). METHODS: Kern's six-step approach was applied when designing the simulation training for OMS residents. The difficulties encountered by the residents when learning OGS were considered when designing the training program. A training course consisting of didactic sessions, hands-on training on three-dimensional training models, and an assessment tool was implemented for OMS residents. Improvement in the confidence and competence of OMS residents in performing OGS, fidelity of the three-dimensional models, and satisfaction with the course was evaluated. RESULTS: All OMS residents (10/10) completed the course. The perceived difficulty in learning OGS was mainly related to the manipulation of the jawbones. While there were improvements in the median confidence and competence scores (3/5 to 4/5), only the differences in competence were found to be statistically significant (p < 0.01, Wilcoxon signed-rank test). Improvements in confidence and competence did not correlate. The mean fidelity scores of both the maxillary and mandibular models were adequate at 3.2 out of 5. Overall, satisfaction with the course was high (5/5). CONCLUSIONS: The six-step approach provides a guided process for educators to formulate a training course directed toward the perceived needs of students. Targeted training can significantly enhance the students' competence. Greater efforts should also be put in place to allow simultaneous developments in the students' confidence along with their competence.

Air Embolism-Induced Ischemic Stroke Following Orthognathic Surgery in a Patient With Goldenhar Syndrome.

Goldenhar syndrome, a rare congenital anomaly, manifests as craniofacial malformations often necessitating intricate surgical interventions. These procedures, though crucial, can expose patients to diverse postoperative complications, including hemorrhage or infection. A noteworthy complication is stroke, potentially linked to air embolism or local surgical trauma. We highlight a case of a male patient, aged 20 years, who experienced a significant postoperative complication of an ischemic stroke, theorized to be due to an air embolism, after undergoing orthognathic procedures for Goldenhar syndrome. The patient was subjected to LeFort I maxillary osteotomy, bilateral sagittal split ramus osteotomy of the mandible, and anterior iliac crest bone grafting to the right maxilla. He suffered an acute ischemic stroke in the left thalamus post-surgery, theorized to stem from an air embolism. Advanced imaging demonstrated air pockets within the cavernous sinus, a rare and concerning finding suggestive of potential air embolism. This case underscores the intricate challenges in treating Goldenhar syndrome patients and the rare but significant risk of stroke due to air embolism or surgical trauma. Limited literature on managing air embolism complications specific to Goldenhar syndrome surgeries exists. Generally, management includes immediate recognition, positional adjustments, air aspiration via central venous catheters, hyperbaric oxygen therapy, hemodynamic support, and high-flow oxygen administration to expedite air resorption. Our patient was conservatively managed post-surgery, and at a 3-month neurology follow-up, he showed significant improvement with only residual right arm weakness. It emphasizes the imperative of a comprehensive, multidisciplinary approach.

Nasal septum-derived chondroprogenitor cells control mandibular condylar resorption consequent to orthognathic surgery: a clinical trial.

Condylar resorption is an aggressive and disability form of temporomandibular joint (TMJ) degenerative disease, usually non-respondent to conservative or minimally invasive therapies and often leading to surgical intervention and prostheses implantation. This condition is also one of the most dreaded postoperative complications of orthognathic surgery, with severe cartilage erosion and loss of subchondral bone volume and mineral density, associated with a painful or not inflammatory processes. Because regenerative medicine has emerged as an alternative for orthopedic cases with advanced degenerative joint disease, we conducted a phase I/IIa clinical trial (U1111-1194-6997) to evaluate the safety and efficacy of autologous nasal septal chondroprogenitor cells. Ten participants underwent biopsy of the nasal septum cartilage during their orthognathic surgery. The harvested cells were cultured in vitro and analyzed for viability, presence of phenotype markers for mesenchymal stem and/or chondroprogenitor cells, and the potential to differentiate into chondrocytes, adipocytes, and osteoblasts. After the intra-articular injection of the cell therapy, clinical follow-up was performed using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and computed tomography (CT) images. No serious adverse events related to the cell therapy injection were observed during the 12-month follow-up period. It was found that autologous chondroprogenitors reduced arthralgia, promoted stabilization of mandibular function and condylar volume, and regeneration of condylar tissues. This study demonstrates that chondroprogenitor cells from the nasal septum may be a promise strategy for the treatment of temporomandibular degenerative joint disease that do not respond to other conservative therapies.

Change in taste sensation after orthognathic surgery.

OBJECTIVE: The objective of this study was to evaluate the effect of orthognathic surgery on taste sensation. MATERIALS AND METHODS: Thirty-five patients scheduled to undergo Le Fort I osteotomy (LFIO), sagittal split ramus osteotomy (SSRO), and bimaxillary surgery (BMS) were evaluated by administering localized and whole-mouth taste tests preoperatively and postoperatively at months 1, 3, and 6. The patients were asked to identify the quality of four basic tastes applied to six locations on the palate and tongue and to rate the taste intensities they perceived. Taste recognition thresholds and taste intesity scores were evaluted according to operation groups and follow-ups. RESULTS: There were significant decreases in the quinine HCl recognition thresholds at the postoperative follow-ups compared to the preoperative in LFIO patients (p = 0.043). There were significant decreases in sucrose taste intensity scores in the right posterolateral part of the tongue at months 3 and 6 compared to preoperative in SSRO patients (p = 0.046), and significant increases in quinine HCL taste intensity scores in the right and left anterior parts of the tongue at month 6 compared to preoperative in LFIO patients (p < 0.05). CONCLUSION: Taste perception is affected due to potential damage to the chemosensory nerves during orthognathic surgical procedures. Generally, non-significant alterations have been observed in taste perception after orthognathic surgery, except for significant alterations in bitter and sweet taste perceptions. CLINICAL RELEVANCE: Maxillofacial surgeons should be aware of taste perception change after orthognathic surgery procedures and patients should be informed accordingly. THE TRIAL REGISTRATION NUMBER (TRN): NCT06103422/Date of registration: 10.17.2023 (retrospectively registered).

Need for orthognathic surgery in cleft patients from Northern Finland.

OBJECTIVE: Northern Finland has a unique distribution of clefts compared to the rest of Europe and Finland. This may reflect the need for orthognathic surgery among Northern Finland's patient pool. The aim of this study was to compare previously operated patients aged 18 years or older with cleft lip, cleft lip and alveolus, cleft lip and palate, cleft palate and to evaluate the need for orthognathic surgery in order to achieve a stable and functional occlusion.  Materials and methods: The study group consisted of all 18-years-old cleft patients treated in the Oulu Cleft Center. The total amount of patients was 110. The patients were compared retrospectively using patients' hospital records. The majority of patients did not have any cleft-associated syndrome. The need for maxillary or bimaxillary orthognathic or corrective-jaw surgery was evaluated by the Oulu Cleft Team. A descriptive and statistical analysis was used to determine the need for orthognathic surgery according to sex and cleft type. RESULTS: There were nineteen patients of the total of 110 patients who met the criteria requiring corrective-jaw surgery (17,3%). In total 12 males (25,0%) and 7 females (11,3%) were evaluated for the need of orthognathic surgery. Sixteen of the 19 patients had palatal involvement of the cleft. CONCLUSIONS: The need for orthognathic surgery was greater in the cleft lip palate and cleft palate patient groups compared to cleft lip alveolus or cleft lip groups. This study also found that males from Northern Finland need surgery more often than females.

The top 100 highly cited articles on surgery-first orthognathic surgery between 2009 and 2022: a bibliometric and visualized analysis.

OBJECTIVES: To reveal research focuses on surgery-first orthognathic surgery by a bibliometric and visualized analysis of the top 100 highly cited articles. STUDY DESIGN: Published papers related to surgery-first orthognathic surgery were retrospectively retrieved from the Web of Science Core Collection from 2009 to 2022. The number of articles, journals, countries/regions, institutions, authors, and keywords were assessed and visualized using CiteSpace software. RESULTS: The top 100 cited articles included 89 research papers and 11 reviews. The average total citation was 21. The most influential article with 146 citations was published by Dr. Liou E.J.W. in 2011. The most common level of evidence was level IV (36 articles). The Journal of Oral and Maxillofacial Surgery had the largest number of papers and the highest total citation frequency. The most productive countries and institutions were Korea/China and Chang Gung Memorial Hospital, respectively. Chen Yu-ray and Choi Jong Woo published 13 and 11 articles with 434 and 299 total citations, respectively. Research interests shifted from skeletal class III malocclusion, accuracy, stability, and relapse to quality of life and virtual surgical planning. CONCLUSION: Our bibliometric analyses provide a comprehensive landscape of the influential topics and developmental trends in surgery-first orthognathic surgery and inspire future studies in this booming field.

Factors associated with quality of life before and after orthognathic surgery.

PURPOSE: Evaluate which factors compromise patients' quality of life who have undergone orthognathic surgery in the pre and postoperative period of 2 years. STUDY DESIGN: In this longitudinal prospective study, 46 adult patients undergoing orthognathic surgery were evaluated. The primary outcome variable was quality of life, assessed using the overall score of the orthognathic quality of life questionnaire (OQLQ) in the pre and 2-year postoperative periods. The predictor variables were axis I (temporomandibular dysfunction) and axis II (psychosocial) RDC/TMD diagnoses, assessed preoperatively and 2 years postoperatively; profile, asymmetry, and open bite preoperatively; and orthodontic treatment active 2 years postoperatively. The covariables were age and sex. The OQLQ score was compared preoperatively and postoperatively using the Wilcoxon test and with the other variables using the Mann-Whitney and Kruskall-Wallis tests. RESULTS: Preoperatively, higher OQLQ scores were associated with myofascial pain (P = .012) and severe depression (P = .030). Two years after surgery, there was an improvement in overall OQLQ (P < .001), myofascial pain (P = .012) and chronic pain (P = .001). However, higher OQLQ scores were associated with individuals who had myofascial pain (P = .012), active orthodontic treatment (P = .007), and other nonspecific physical symptoms including pain (NSPSIP) (P = .049). CONCLUSION: Quality of life was affected preoperatively by myofascial pain and depression, and although it improved significantly 2 years after surgery, it continued to be affected by myofascial pain, NSPSIP, and active orthodontic treatment.

The online attention analysis on orthognathic surgery research.

OBJECTIVES: Altmetrics is one of the fields of bibliometrics that seeks to assess the impact and interest of a given subject through Internet users. The aim of this study is to make an altmetric analysis of the orthognathic surgery literature. METHODS: A literature search was conducted using Dimensions app up to December 2023. A list of the 100 most mentioned articles on the topic was compiled. A Google Trends search was performed with same strategy to visualize important data regarding internet search. Charts and tables were created using Microsoft Excel and VOSviewer software to allow bibliometric visualization. RESULTS: There was a very poor correlation between the number of mentions and the number of citations (r = 0.0202). Most articles discussed on technical innovations associated to orthognathic surgery, majority related to virtual planning (n = 26). Other topics considered interesting to internet readers were complications (n = 18), surgical technique (n = 14), and psychological aspects/quality of life (n = 13). CONCLUSION: Online interest in orthognathic surgery closely aligns with the level of academic interest but is also influenced by factors such as location and economic status. The internet is a powerful tool for disseminating scientific research to a broad audience, making it more accessible and engaging than traditional academic channels.

Prevention of postoperative nausea and vomiting after orthognathic surgery: a scoping review.

INTRODUCTION: Postoperative nausea and vomiting (PONV) is one of the most common adverse events following orthognathic surgery. It's a distressing feeling for patients and continues to be the cause of postoperative complications such as bleeding, delayed healing, and wound infection. This scoping review aims to identify effective PONV prophylaxis strategies during orthognathic surgery that have emerged in the past 15 years. METHODS: We searched Pubmed, Cochrane Controlled Register of Trials, and Embase from 2008 to May 2023. Studies meeting the following criteria were eligible for inclusion: (1) recruited patients undergo any orthognathic surgery; (2) evaluated any pharmacologic or non-pharmacologic method to prevent PONV. Studies meeting the following criteria were excluded: (1) case series, review papers, or retrospective studies; (2) did not report our prespecified outcomes. RESULTS: Twenty-one studies were included in this review. Pharmacological methods for PONV prevention include ondansetron and dexamethasone (3 studies), peripheral nerve block technique (4 studies), dexmedetomidine (1 study), pregabalin (2 studies), nefopam (2 studies), remifentanil (1 study), propofol (2 studies), and penehyclidine (1 study). Non-pharmacologic methods include capsicum plaster (1 study), throat packs (2 studies) and gastric aspiration (2 studies). CONCLUSIONS: Based on current evidence, we conclude that prophylactic antiemetics like dexamethasone, ondansetron, and penehyclidine are the first defense against PONV. Multimodal analgesia with nerve block techniques and non-opioid analgesics should be considered due to their notable opioid-sparing and PONV preventive effect. For the non-pharmacological methods, throat packs are not recommended for routine use because of their poor effect and serious complications. More prospective RCTs are required to confirm whether gastric aspiration can prevent PONV effectively for patients undergoing orthognathic surgery.

Validation of a fully automatic three-dimensional assessment of orthognathic surgery.

The aim of the present study was to propose and validate FAST3D: a fully automatic three-dimensional (3D) assessment of the surgical accuracy and the long-term skeletal stability of orthognathic surgery. To validate FAST3D, the agreement between FAST3D and a validated state-of-the-art semi-automatic method was calculated by intra-class correlation coefficients (ICC) at a 95 % confidence interval. A one-sided hypothesis test was performed to evaluate whether the absolute discrepancy between the measurements produced by the two methods was statistically significantly below a clinically relevant error margin of 0.5 mm. Ten subjects (six male, four female; mean age 24.4 years), class II and III, who underwent a combined three-piece Le Fort I osteotomy, bilateral sagittal split osteotomy and genioplasty, were included in the validation study. The agreement between the two methods was excellent for all measurements, ICC range (0.85-1.00), and fair for the rotational stability of the chin, ICC = 0.54. The absolute discrepancy for all measurements was statistically significantly lower than the clinical relevant error margin (p < 0.008). Within the limitations of the present validation study, FAST3D demonstrated to be reliable and may be adopted whenever appropriate in order to reduce the work load of the medical staff.

Influencing factors for the development of obstructive sleep apnea after orthognathic surgery in skeletal class III patients: A systematic review.

This systematic review aimed to investigate the factors that may contribute to the development of OSA after orthognathic surgery in patients with skeletal class III. Electronic searches of PubMed, Embase, Web of Science, and Cochrane databases were conducted up to December 10, 2022. In total, 277 studies were retrieved and screened according to the inclusion and exclusion criteria, and 14 were finally selected. All studies were of medium quality (moderate risk of bias). The occurrence of OSA after orthognathic surgery in patients with class III skeletal relationships depends on surgical factors and patient self-factors. Surgical factors include surgery type, amount of maxillary and mandibular movement, and the patient's postoperative swelling. Patient self-factors include weight, age, gender, and hypertrophy of the soft palate, tonsils, and tongue. According to information in the 14 selected articles, the incidences of OSA after Le Fort I impaction and BSSO setback, BSSO setback, and Le Fort I advancement and BSSO setback were 19.2%, 8.57%, and 0.7%, respectively, mostly accompanied with greater amounts of mandibular recession. However, no clear evidence exists to confirm that orthognathic surgery is a causative factor for postoperative sleep breathing disorders in patients with mandibular prognathism. The wider upper airway in patients with class III skeletal might be the reason for the rare occurrence of OSA after surgery. In addition, obesity and advanced age may lead to sleep apnea after orthognathic surgery. Obese patients should be advised to lose weight preoperatively.

The effect of tongue reduction for preventing adverse effects in patients undergoing class III orthognathic surgery: a three-dimensional comparative analysis.

OBJECTIVES: This study aims to evaluate the potential benefits of combining tongue reduction with mandibular setback surgery in patients undergoing class III orthognathic surgery. Specifically, we investigated whether this combined approach reduced the risk of surgical relapse, condylar resorption, and airway space reduction by mitigating tongue pressure on the mandible. MATERIAL AND METHODS: The study retrospectively enrolled patients who had undergone bilateral sagittal split ramus osteotomy (BSSRO) with at least 5 mm of setback and met the criteria of a body mass index > 20 kg/m2 and tongue volume > 100 mm3. The study included 20 patients with 10 in the tongue reduction group (TR, n = 10) and 10 in the BSSRO only group (SO, n = 10). RESULTS: The volumetric changes of the total airway space were significantly different between the TR and SO groups (p = 0.028). However, no significant differences were observed in the condylar resorption and postoperative relapse between the groups (p = 0.927 and 0.913, respectively). The difference between the resorption of the anterior and posterior segments of the condyle was also statistically insignificant (p = 0.826). Postoperative counterclockwise rotation of the proximal segment only demonstrated a significant correlation with postoperative relapse (p = 0.048). CONCLUSIONS: The reduction in tongue volume demonstrated a preventive effect on the reduction of the airway space after mandibular setback, although it did not yield statistical significance concerning surgical relapse and condylar volume. The counterclockwise rotation of the proximal segment might be responsible for the forward displacement of the distal segment and postoperative relapse. However, the clinical implications of this finding should be interpreted with caution owing to the limited sample size CLINICAL RELEVANCE: Tongue reduction could potentially serve as a preventive measure in preserving the airway space and might be beneficial in mitigating the risk of obstructive sleep apnea in patients with class III deformity.

Machine learning-based decision support system for orthognathic diagnosis and treatment planning.

BACKGROUND: Dento-maxillofacial deformities are common problems. Orthodontic-orthognathic surgery is the primary treatment but accurate diagnosis and careful surgical planning are essential for optimum outcomes. This study aimed to establish and verify a machine learning-based decision support system for treatment of dento-maxillofacial malformations. METHODS: Patients (n = 574) with dento-maxillofacial deformities undergoing spiral CT during January 2015 to August 2020 were enrolled to train diagnostic models based on five different machine learning algorithms; the diagnostic performances were compared with expert diagnoses. Accuracy, sensitivity, specificity, and area under the curve (AUC) were calculated. The adaptive artificial bee colony algorithm was employed to formulate the orthognathic surgical plan, and subsequently evaluated by maxillofacial surgeons in a cohort of 50 patients. The objective evaluation included the difference in bone position between the artificial intelligence (AI) generated and actual surgical plans for the patient, along with discrepancies in postoperative cephalometric analysis outcomes. RESULTS: The binary relevance extreme gradient boosting model performed best, with diagnostic success rates > 90% for six different kinds of dento-maxillofacial deformities; the exception was maxillary overdevelopment (89.27%). AUC was > 0.88 for all diagnostic types. Median score for the surgical plans was 9, and was improved after human-computer interaction. There was no statistically significant difference between the actual and AI- groups. CONCLUSIONS: Machine learning algorithms are effective for diagnosis and surgical planning of dento-maxillofacial deformities and help improve diagnostic efficiency, especially in lower medical centers.

Feasibility of simultaneous TMJ arthroscopy in ADDwoR patients undergoing orthognathic surgery for jaw deformity.

This study evaluated the feasibility of simultaneous temporomandibular joint (TMJ) arthroscopy and orthognathic surgery as a new treatment strategy for anterior disc displacement without reduction (ADDwoR) patients with severe jaw deformities. Twelve ADDwoR patients with facial deformities who underwent arthroscopy and orthognathic surgery between September 2015 and December 2019 were retrospectively evaluated. Pre- and postoperative maximum incisal opening (MIO) and joint pain were recorded. Computed tomography (CT) and three-dimensional cephalometric analysis were performed at 3 (T1) and ≥6 (T2) months postoperatively. Magnetic resonance imaging (MRI) of the TMJ was performed before, ≤7 days after and ≥6 months after surgery. The lateral profile radiological findings, the symmetry of the maxilla and mandible, and the MRI measurements were compared. Anterior disc displacement did not recur, and the maximum incisal opening (MIO) increased from 27.4 mm to 32.7 mm after surgery (p < 0.05). No significant differences were found in the lateral profile, symmetry indices or condylar height via MRI between T1 and T2. Joint morphology and the position of both the maxilla and mandible remained stable during postoperative follow-up, while joint symptoms were markedly relieved and facial appearance was noticeably improved. Combined arthroscopy and orthognathic surgery is effective and recommended for ADDwoR patients with jaw deformities.

Evaluation of bone contact area and intercondylar distance changes in orthognathic surgery - a comparison between BSSO and HSSO technique depending on mandibular displacement extent.

OBJECTIVES: The present study aims to assess the impact of bilateral and high oblique sagittal split osteotomy (BSSO/HSSO), as well as displacement distances and directions on the expected and achievable bone contact area (BCA) and changes in the intercondylar distance (ICD). The primary question addressed is whether mandibular splitting through BSSO results in a greater BCA and/or ICD when compared to splitting through HSSO. MATERIALS AND METHODS: Totally 80 mandibular displacements were performed on 20 fresh cadavers, for each subject, four splints were produces to facilitate mandibular advancement as well as setbacks of 4 and 8 mm. Pre- and postoperative CBCT scans were performed to plan the surgical procedures and to analyze the expected and achieved BCA and ICD. RESULTS: Regarding the maximum mandibular displacement, the expected BCA for HSSO/BSSO were 352.58 ± 96.55mm2 and 1164.00 ± 295.50mm2, respectively, after advancement and 349.11 ± 98.42mm2 and 1344.70 ± 287.23mm2, respectively, after setback. The achieved BCA for HSSO/BSSO were 229.37 ± 75.90mm2 and 391.38 ± 189.01mm2, respectively, after advancement and 278.03 ± 97.65mm2 and 413.52 ± 169.52 mm2, respectively after setback. The expected ICD for HSSO/BSSO were 4.51 ± 0.73 mm and 3.25 ± 1.17 mm after advancement and - 5.76 ± 1.07 mm and - 4.28 ± 1.58 mm after setback. The achieved ICD for HSSO/BSSO were 2.07 ± 2.9 mm and 1.7 ± 0.60 mm after advancement and - 2.57 ± 2.78 mm and - 1.28 ± 0.84 mm after setback. Significant differences between the BCA after HSSO and BSSO were at each displacement (p < 0.001), except for the achieved BCA after 8-mm setback and advancement (p ≥ 0.266). No significant differences were observed regarding ICD, except for the expected ICD after 8-mm setback and advancement (p ≤ 0.037). CONCLUSIONS: Compared to the virtual planning, the predictability regarding BCA and ICD was limited. ICD showed smaller clinical changes, BCA decreased significantly in the BSSO group. CLINICAL RELEVANCE: BCA and ICD might have been less important in choosing the suitable split technique. in orthognathic surgery.

Three-dimensional positioning of the maxilla using novel intermediate splints in maxilla-first orthognathic surgery for correction of skeletal class III deformity.

OBJECTIVES: Successful orthognathic surgery requires accurate transfer of the intraoperative surgical plan. This study aimed to (1) evaluate the surgical error of a novel intermediate splint in positioning the maxilla during maxilla-first orthognathic surgery and (2) determine factors influencing surgical error. MATERIALS AND METHODS: This prospective study examined 83 patients who consecutively underwent Le Fort I osteotomy for correction of skeletal class III deformity using a novel intermediate splint and a bilateral sagittal split osteotomy. Surgical error was the outcome variable, measured as the difference in postoperative translational and rotational maxillary position from the virtual plan. Measures included asymmetry, need and amount for mandibular opening during fabrication of intermediate splints, and planned and achieved skeletal movement. RESULTS: Mean errors in translation for vertical, sagittal, and transversal dimensions were 1.0 ± 0.7 mm, 1.0 ± 0.6 mm, and 0.7 ± 0.6 mm, respectively; degrees in rotation for yaw, roll, and pitch were 0.8 ± 0.6, 0.6 ± 0.4, and 1.6 ± 1.1, respectively. The transverse error was smaller than sagittal and vertical errors; error for pitch was larger than roll and yaw (both p < 0.001). Error for sagittal, transverse, and roll positioning was affected by the achieved skeletal movement (roll, p < 0.05; pitch and yaw, p < 0.001). Surgical error of pitch positioning was affected by planned and achieved skeletal movement (both p < 0.001). CONCLUSIONS: Using the novel intermediate splint when performing Le Fort I osteotomy allowed for accurate positioning of the maxilla. CLINICAL RELEVANCE: The novel intermediate splint for maxillary positioning can be reliably used in clinical routines.