Occlusal and Cephalometric Outcomes of Cleft Orthognathic Surgery: A Retrospective Cohort Study.

OBJECTIVES: Aberrant facial growth in individuals affected by orofacial clefts can result in maxillary retrusion and class III malocclusion, with a proportion requiring surgical correction at cessation of growth. This study aimed to evaluate occlusal and cephalometric outcomes of combined orthodontic-orthognathic treatment. MATERIAL AND METHODS: Retrospective cohort study in a United Kingdom cleft center. Participants included twenty-seven patients (20 males, 7 females) with cleft (n = 16 UCLP :7 BCLP :4 ICP) who consecutively underwent combined surgical treatment for Class III malocclusion between January 2013 and December 2017. Records were collected pre-treatment (T0), pre-surgery (T1) and at debond (T2). Models were scored using the Peer Assessment Rating (PAR) index and cephalometric radiographs were traced and analyzed. Outcomes were assessed by an independent rater. RESULTS: Mean age at surgery was 21.4 years (SD 4.9). Le Fort 1 advancement (mean 6.1 mm, SD 4.0) was performed in all cases. Additional procedures included mandibular setback (n = 2), cortico-cancellous bone grafting (n = 6) and genioplasty (n = 1). Mean T0 PAR score was 44.8 (SD 11.7), reducing to 3.6 (SD 2.0) at T2, indicating a mean % PAR score reduction of 91.6% (SD 4.7). Class III skeletal profiles improved from a mean T0 ANB of -2.1º (SD 2.2), to 2.8º (SD 1.6) at T2. Mean T0 overjet was -3.3 mm (SD 2.3), increasing to 2.6 mm (SD 1.3) at T2. CONCLUSION: Cleft orthognathic surgery differs in complexity and approach to routine orthognathics, however, these results demonstrate that occlusal outcomes can still be comparable with non-cleft populations. Outcome data can be used for comparison with other centers providing cleft orthognathic treatment.

Safety of vertical osteotomies in segmental Le Fort I procedures: a one-year radiological follow-up study.

The aim of this study was to evaluate dental and periodontal injuries and radiological bone healing at vertical osteotomies in patients treated with segmental Le Fort I (LFI) osteotomy, using cone beam computed tomography (CBCT) scans. This retrospective study analyzed 105 patients who underwent segmental LFI osteotomy. Vertical osteotomies were performed between the lateral incisor and canine using a bur and osteotome. CBCT scans were taken preoperatively and at 1-week and 1-year follow-ups. Measurements at 1-week included interdental distances, root injuries, and periodontal detachment, while 1-year follow-up assessed endodontic treatment and osteotomy healing. Results showed no damage to the 420 roots at risk, though 38 roots had osteotomy extensions into the periodontal ligament. The mean preoperative minimum distance between roots was significantly different between sites with intact and detached periodontal ligaments (P < 0.001). One tooth required endodontic treatment at 1-year follow-up. Incomplete healing of vertical osteotomies was more frequent in female patients (P = 0.012). The findings suggest that segmental LFI osteotomy is safe when performed with a bur and osteotome, provided a minimum distance of 2.5 mm between roots is maintained.

Retrospective Study on the Incidence of Postoperative Nausea and Vomiting and Hypotension During Orthognathic Surgery Using Propofol or Remimazolam.

Objective: This study aimed to evaluate the incidence of early (up to 2 h) and late (2-24 h) postoperative nausea and vomiting (PONV) and hypotension in patients who underwent general anesthesia for orthognathic surgery using propofol or remimazolam along with remifentanil. Methods: This retrospective chart review included healthy adult patients under the age of 60 who underwent orthognathic surgery using propofol (P group) or remimazolam (R group) from January 2021 to March 2022. Records were reviewed to gather PONV and intraoperative hypotension data as well as patient characteristics and other variables. Results: Early PONV was significantly lower in the P group vs the R group (9.5% vs 34.1%, respectively; P = .002), although the difference in late PONV was insignificant (36.9% vs 51.2%, respectively; P = .13). A higher incidence of intraoperative hypotension was noted in the P group (22.6%) vs the R group (2.4%; P = .004); however, there were no differences in average intraoperative systolic blood pressure or vasopressor administration. Conclusion: These results suggest that propofol is associated with a lower incidence of early PONV as compared to remimazolam; however, antiemetics are still recommended given the frequency of late PONV in both groups. Propofol also caused more episodes of intraoperative hypotension vs remimazolam, but the increase in transient hypotension is likely to be irrelevant during orthognathic surgery in healthy adults under the age of 60.

Efficacy of the Coronoid Notch and Occlusal Plane As Predictable Landmarks for Determining the Medial Cut Height in Bilateral Sagittal Split Osteotomy: A Split-Mouth Observational Study.

AIM: This split-mouth observational study was conducted to assess the reliability and safety of using the coronoid notch and occlusal plane as landmarks to aid surgeons during bilateral sagittal split osteotomy (BSSO). MATERIALS AND METHODS: Thirteen patients between the ages of 18 and 30 years, with class II and class III mandibular skeletal malocclusion requiring BSSO, were randomly selected and assigned to each of the study and control groups. A split-mouth study was chosen to conduct this research. Cone beam computed tomography (CBCT) imaging was conducted before the surgery to evaluate the anatomical structure, and three predefined points were marked at the superiormost point of the mandibular foramen, the inferiormost point of the mandibular foramen, and the deepest point of the sigmoid notch. A conventional sagittal split osteotomy was carried out in the control group. Preoperative values were obtained in the study group using the CBCT imaging technique by drawing an imaginary line from the inferiormost part of the mandibular foramen to the line corresponding to the occlusal plane that extended beyond the last molar. The lingual flap reflection was restricted to the internal oblique ridge. The posterior border of the mandible was not reflected. The measurements acquired via CBCT imaging were accurately transferred to the intraoperative surgical site using a vernier caliper. This facilitated the precise completion of the horizontal osteotomy, ascending ramus cuts, and vertical osteotomies. BSSO was performed, the mandibular setback or advancement was done with intermaxillary fixation, and the procedure was completed by rigid fixation. Types of lingual splits, types of lateral bone cut ends (LBCEs), any unfavorable split, and the time taken for the surgery (in minutes) were assessed. RESULTS: The surgery time in the control group (20.1538 ± 2.85325 min) was found to be higher than that in the study group (17.6154 ± 3.59487 min), with a p-value of 0.02. No significant differences were observed when assessing the presence of unfavorable splits in both groups (p = 0.500). Buccal LBCEs were the most prevalent, followed by inferior types. Type I lingual split was the most common in the study group (70%). CONCLUSION: This technique offers a dependable anatomical reference and significantly reduces surgical time for beginners. Additionally, the patterns of the lingual split were correlated with the types of lateral bone cut ends.

Effect of maxillary advancement on velopharyngeal function in cleft lip and palate: 20 years of experience.

This retrospective study aimed to investigate the impact of orthognathic surgery with maxillary advancement (MA) on the velopharyngeal function (VF) in individuals with cleft lip and palate (CLP). The study included 651 patients with repaired CLP, both sexes, aged over 18 years who underwent MA alone or in combination with nasal procedures and/or mandibular osteotomy, operated between 2000 and 2019. The main outcome measures were nasalance (nasal text-NT and oral text-OT) and velopharyngeal orifice area measurement (VA), determined by nasometry and pressure-flow technique, respectively. Preoperatively, mean nasalance scores for NT and OT indicated normality, and VA demonstrated borderline-inadequate velopharyngeal closure in all patients. Following MA, a significant increase in nasalance scores for NT and OT occurred (p < 0.001), revealing hypernasality in those undergoing MA combined with nasal procedure (MAN, N = 191), bimaxillary orthognathic surgery with nasal procedure (BON, N = 227) and bimaxillary orthognathic surgery (BO, N = 151). Conversely, nasalance scores remained within the normal range for those undergoing isolated maxillary advancement (IMA, N = 82). VA exhibited a significant increase leading to the classification of VF as inadequate in the BON and MAN groups. Overall, MA contributed to VF deterioration, resulting in the appearance of hypernasality and increased VA, particularly when combined with nasal procedures.

The use of ChatGPT and Google Gemini in responding to orthognathic surgery-related questions: A comparative study.

AIM: This study employed a quantitative approach to compare the reliability of responses provided by ChatGPT-3.5, ChatGPT-4, and Google Gemini in response to orthognathic surgery-related questions. MATERIAL AND METHODS: The authors adapted a set of 64 questions encompassing all of the domains and aspects related to orthognathic surgery. One author submitted the questions to ChatGPT3.5, ChatGPT4, and Google Gemini. The AI-generated responses from the three platforms were recorded and evaluated by 2 blinded and independent experts. The reliability of AI-generated responses was evaluated using a tool for accuracy of information and completeness. In addition, the provision of definitive answers to close-ended questions, references, graphical elements, and advice to schedule consultations with a specialist were collected. RESULTS: Although ChatGPT-3.5 achieved the highest information reliability score, the 3 LLMs showed similar reliability scores in providing responses to orthognathic surgery-related inquiries. Moreover, Google Gemini significantly included physician recommendations and provided graphical elements. Both ChatGPT-3.5 and -4 lacked these features. CONCLUSION: This study shows that ChatGPT-3.5, ChatGPT-4, and Google Gemini can provide reliable responses to inquires about orthognathic surgery. However, Google Gemini stood out by incorporating additional references and illustrations within its responses. These findings highlight the need for an additional evaluation of AI capabilities across different healthcare domains.

Electroacupuncture Protocol for Sensory and Motor Function Recovery After Orthognathic Surgery: a Randomized Clinical Trial.

Importance: Orthognathic surgery is utilized to rectify facial deformities, but it can lead to neurosensory alterations. Electroacupuncture has been shown to enhance sensitivity and motor functions in patients post-surgery. However, its application in traumatic facial injuries remains inadequately researched. Objective: To investigate the effects of electroacupuncture on sensitivity and orofacial function in patients undergoing orthognathic surgery. Design, Setting, and Population: A randomized clinical trial involving patients undergoing bimaxillary orthognathic surgery and genioplasty who are randomly allocated to either a physiotherapy (PT) or physiotherapy plus electroacupuncture group (PTEA). Exposures: Participants will be allocated to their respective therapies for a duration of six weeks. The PT group will receive a 50-minute physical therapy session along with 30 minutes of simulated procedure. The PTEA group will receive 50 minutes of physical therapy followed by 30 minutes of electroacupuncture. Main Outcomes and Measures: Before treatment, sensitivity will be assessed using the SMILE Sensitivity Test-BAURU kit, edema will be evaluated using the MD Anderson Cancer Center Head and Neck Lymphedema protocol, range of motion will be measured using a digital caliper, and muscle pain and fatigue will be gauged using numerical scales. The chewing function will be evaluated using the Chewing Quality Assessment Questionnaire. Results: All assessments will be repeated at three and six months following the initiation of treatment. Conclusions and Relevance: This study may provide reliable and high-quality clinical evidence regarding the impact of electroacupuncture on restoring altered sensation and motor function in patients undergoing orthognathic surgery.

Comprehensive treatment approach for hemifacial microsomia: Integrating orthognathic surgery with sequential customized implantation.

OBJECTIVE: This study aimed to evaluate the clinical outcomes of combining orthognathic surgery with staged patient-specific implants (PSIs) for comprehensive craniofacial asymmetry reconstruction in adult patients with hemifacial microsomia (HFM). METHODS: Six adults with HFM (1 Type I and 5 Type IIa) underwent orthognathic surgery to correct skeletal malocclusion and chin deviation. Sequential PSIs were implanted to address craniofacial asymmetry. Digital lateral cephalograms and cranial computed tomography scans were obtained at four time points: pre-orthognathic surgery (T0), within three months after orthognathic surgery (T1), one year after orthognathic surgery and just before personalized implantation (T2), and after personalized implantation (T3). Evaluation parameters included skeletal and dentoalveolar measures, occlusal cant, chin deviation, skeletal stability, and facial contour symmetry. RESULTS: At T1, no significant differences were observed in skeletal movements compared with planned surgical movements (p > 0.05). Similarly, at T2, skeletal movements did not significantly differ from those observed at T1 (p > 0.05), indicating surgical precision and stability. Analysis of skeletal and dentoalveolar parameters, occlusal cant, and chin deviation revealed significant increases in SNB, FH-NPo, and ST N vert-Pog at T1 compared to T0 (p < 0.05), along with notable improvements in chin deviation and occlusal cant (p < 0.05). Comparison of T2 to T1 showed no significant changes in SNB, FH-NPo, ST N vert-Pog, chin deviation, or occlusal cant (p > 0.05), indicating substantial postoperative stability. After personalized implantation (T3), further significant improvements were observed in skeletal symmetry. CONCLUSION: Combining orthognathic surgery with staged PSIs effectively reconstructs craniofacial asymmetry in adult patients with HFM, achieving significant improvements in skeletal alignment, occlusal cant, and chin deviation, with stable outcomes over time.

Masticatory function and three-dimensional facial morphology of soft tissues: One year after orthognathic surgery.

OBJECTIVE: Dentofacial deformities (DFD) require orthodontic treatment, orthognathic surgery, and speech therapy for aesthetic and functional problems. This longitudinal study analyzed changes in masticatory function and three-dimensional (3D) facial soft tissue in patients with Class II and Class III DFD after orthognathic surgery. In addition, the study investigated the relationship between facial measurements, maximum bite force (MBF), and orofacial myofunctional status (OMS). DESIGN: The sample consisted of 46 participants, including 10 patients with Class II DFD, and 11 patients with Class III DFD. These groups were assessed before (T0) and 6 months (T1) after surgery. Twelve patients who completed the treatment protocol were evaluated 12 months post-surgery (T2). The patient groups were compared with each other and with a control group (CG) of 25 healthy subjects. The participants underwent MBF and clinical evaluation of OMS, including masticatory behavior, using a validated protocol. The 3D facial soft tissue was assessed using laser scanning. RESULTS: Compared to the CG, DFD patients showed reduced MBF, masticatory behavior, and OMS scores at T0. At T2, there was an improvement in MBF, masticatory, and OMS scores, but differences were observed compared to the CG. Changes in facial soft tissue followed the underlying hard tissue movement resulting from surgery, and reduction of vertical measurements contributed to improvements in masticatory function. CONCLUSION: These findings indicated that combined surgery, orthodontic treatment, and speech therapy can lead to a significant improvement in masticatory function and facial soft tissue in DFD patients, although not completely 12 months post-surgery.

Effects of condylar neck inclination and counterclockwise rotation on the stress distribution of the temporomandibular joint.

Three different kinds of condylar inclination were manually modelled anteriorly inclined condylar neck, vertical condylar neck, and posteriorly inclined condylar neck. Three different maxillary impactions were simulated to evaluate the effect of counterclockwise rotation. The von Misses stresses of the disc, compressive stresses of the glenoid fossa, and compressive stresses of the condyle were the highest in the models with posteriorly inclined neck and lowest in the models with vertical condylar neck design. Stresses of the temporomandibular joint increase with the counterclockwise rotation of the maxilla-mandibular complex. The posteriorly inclined neck should be considered a risk factor for condylar resorption with increased counterclockwise rotation.

Honoring Professor Hugo Lorenz Obwegeser: A Visionary in Maxillofacial Surgery and Orthodontics.

Hugo Lorenz Obwegeser was a pioneering Austrian surgeon whose contributions profoundly transformed the field of maxillofacial surgery. His groundbreaking work marked a pivotal turning point, enabling more sophisticated and effective corrections of facial deformities. Obwegeser revolutionized his area of expertise by introducing innovative osteotomies of the mandible and maxilla, which became foundational techniques for addressing facial asymmetries. In addition to his surgical advancements, Obwegeser was a key figure in establishing the European Association for Cranio-Maxillo-Facial Surgery, helping to define the modern scope of the specialty. His legacy in maxillofacial surgery is distinguished by his unwavering commitment to innovation, mentorship, and the continuous advancement of surgical practices. This article aims to honor the extraordinary achievements of Hugo Lorenz Obwegeser and his lasting impact on the field of maxillofacial surgery.

Screening of Sensorial and Inflammatory Changes in Patients Submitted to Orthognathic Surgery.

BACKGROUND: Despite the high levels of success after orthognathic surgery, the immediate postoperative pain and edema, besides the neurosensorial deficits, are common complications. OBJECTIVE: This study aimed to evaluate the pattern of sensory and inflammatory responses in patients undergoing orthognathic surgery. METHODS: This prospective observational study included 20 patients undergoing bimaxillary orthognathic surgery, who were evaluated in the preoperative period and on Days 1, 2, 3, 4, 5, 6, 7, and 30 after surgery, using a battery of tests to assess sensorial and inflammatory changes. RESULTS: Subjective and objective evaluations of edema indicated a trend toward edema resolution within 30 days, with a significant decrease in mouth opening on days 1, 7, and 30 after surgery. Regarding nasal obstruction, a significant increase in Nasal Obstruction Symptom Evaluation (NOSE) scores was demonstrated on the first, second, and third days, returning to preoperative levels after 30 days. There was a significant increase in visual analogic scale (VAS) scores from the first to the seventh day after surgery, with a reduction within 30 days. For mechanical and thermal sensitivity tests, the lower lip and chin regions had poorer results, without recovery after 30 days. Positive correlations were observed between painful and inflammatory parameters, as well as between subjective and objective evaluations. Analysis of saliva biomarkers did not show significant differences for pre- and postoperative CCL3 or CCL4 levels. CONCLUSION: Data provide new evidence about the early inflammatory and sensorial complications after orthognathic surgery.

Evaluation of soft tissue profile changes around the nose and upper lip following maxillary anterior alveolar osteotomy with Wassmund and Wunderer technique in Japanese.

PURPOSE: The extent to which maxillary anterior alveolar osteotomy alters the facial profile remains unclear. The present study retrospectively analyzed and evaluated changes in maxillary anterior fragments and soft tissue from the nose to upper lip from pre- to postoperatively in patients who underwent the Wassmund and Wunderer (WW) technique. METHODS: Thirty-seven Japanese patients with maxillary prognathism underwent orthognathic surgery with the WW technique were retrospectively included in the present study. Changes in both hard- and soft-tissue landmarks and correlations between both tissues were evaluated using lateral cephalograms taken immediately before and ≥6 months after orthognathic surgery. RESULTS: The maxillary anterior segment showed predominantly posterior movement, with only slight upward movement. Posterior shift and lingual inclination of the maxillary anterior teeth were prominent. As for soft tissues, the change in the nasal tip was small and posterior change was large in the subnasal and upper lip areas. Nasolabial angle, nasal height, and inclination of nasal tip increased, while upper lip protrusion, nasal tip angle, and philtrum length decreased. Correlations were found between posterior changes in hard tissues and posterior changes in soft tissues. Among these, posterior changes and lingual inclination of the maxillary anterior teeth strongly correlate with posterior changes of the upper lip. CONCLUSION: Posterior shift of the maxillary anterior segment using the WW technique is useful because it can greatly improve the protrusion of the upper lip while minimizing nasal morphological changes, and the positioning of the maxillary anterior teeth may be an important key factor.

Changes in mandibular angle and intergonial width after bilateral sagittal split ramus osteotomy or bimaxillary surgery with/without counterclockwise rotation.

The aim of this retrospective study was to evaluate the morphological changes in the mandibular angle area after orthognathic surgery with or without mandibular counterclockwise rotation in Class II deformity patients, and to investigate the associated factors. Computed tomography scans obtained preoperatively (T0), within 1 month postoperatively (T1), and 6 months postoperatively (T2) were collected from 58 patients who underwent either bilateral sagittal split ramus osteotomy (group I), bimaxillary surgery with mandibular counterclockwise rotation (group II), or bimaxillary surgery without mandibular counterclockwise rotation (group III). The intergonial width increased after surgery, by 2.78 ± 2.02 mm in group I, 2.86 ± 2.81 mm in group II, and 2.53 ± 2.42 mm in group III (all P < 0.001). The mandibular angle (MA) increased in group I (ΔMA 4.76 ± 2.79°; P < 0.001) and group III (ΔMA 3.50 ± 2.58°; P < 0.001); however no significant increase was observed in group II. The increase in intergonial width was positively correlated with the lateral displacement of the proximal segment. Counterclockwise rotation of the proximal segment resulted in an increase in MA, while counterclockwise rotation resulted in a reduction in this increasing trend. The results indicate that reducing the displacement and rotation of the proximal segments is key to minimizing changes in the mandibular angle area.

Three-dimensional changes in the mandibular condyle in skeletal class III patients treated with orthognathic surgery: a systematic review.

This systematic review aimed to evaluate the available evidence on the incidence and quantification of 3-dimensional changes in mandibular condyles after orthognathic surgery by bilateral sagittal split osteotomy (BSSO), with or without maxillary surgery, in class III symmetrical or asymmetrical individuals. The databases PubMed, Lilacs, Web of Science, Embase, SciELO, Scopus, EBSCO, Cochrane, and Google Scholar were surveyed and the study was registered on the PROSPERO (CRD42022383594). The selected studies met the criteria established by the PICO model: 1: Population - individuals over 18 years of age with class III dentofacial skeletal deformities; 2: Intervention - orthognathic surgery using BSSO; 3: Comparison - condylar tomographic measurements (volume, thickness, height, and width) prior to the surgical procedure; and 4: Results - condylar tomographic measurements (volume, thickness, height, and width) at least 12 months after surgery. Initially, 800 articles were identified. After excluding 694 duplicates and screening 153, nine studies met the inclusion criteria for data extraction and analysis. Six evaluated class III symmetrical individuals, and three assessed those with mandibular asymmetry. A total of 233 patients (92 males and 141 females) were studied. Analysis of 466 condyles revealed minimal bone remodelling, with resorption averaging from -0.03 to -0.94 mm and apposition from 0.01 to 0.34 mm. Data analysis showed minimal changes in condylar morphology post BSSO with or without maxillary surgery, indicating predictable skeletal stability. Bias (ACROBAT-NRSI guidelines) did not affect data reliability, and no occlusal changes were observed. The main limitations of the study were heterogeneous imaging techniques, varied study designs, diverse populations, and inconsistent protocols. Further trials with standardised cone-beam computed tomography are needed to enhance remodelling and volume measurement reliability. This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Cuff tear of endotracheal tube induced by a palatal orthodontic device during nasotracheal intubation: a case report.

Orthognathic surgery often requires intraoral orthodontic appliances that are fixed directly to the bone, which can complicate nasotracheal intubation if the devices protrude into the nasal cavity. This case report describes a 19-year-old man scheduled for elective orthognathic surgery who experienced recurrent cuff tears of the endotracheal tube during nasotracheal intubation due to protruding orthodontic screws in the palate. Despite initial attempts at nasotracheal intubation through the left nostril, the cuff of the 7.0 mm internal diameter (ID) Ring, Adair & Elwyn (RAE) tube repeatedly ruptured, with identical rupture patterns observed. Facial CT revealed that the orthodontic screws had protruded into both nasal cavities with significant visibility in the sagittal, coronal, and transverse views. Fiberoptic examination of the left nasal passage identified a firm protrusion below the inferior turbinate, corresponding to the location of the screw, which likely caused the cuff tears. Intubation was successfully performed via the right nostril during the fiberoptic examination. This case highlights the critical importance of evaluating intraoral corrective devices using comprehensive craniofacial imaging before anesthesia induction, as well as conducting fiberoptic examinations during intubation to avoid complications and ensure patient safety.

Reshaping Faces, Redefining Risks: A Systematic Review of Orthognathic Surgery Outcomes in Cleft Lip and Palate Patients.

Background: This study aims to determine a generalized outcome and risk profile for patients undergoing orthognathic surgery for the definitive treatment of cleft lip and palate. Furthermore, we hope to determine the key risk factors that cause increased risk for cleft lip and palate patients undergoing orthognathic surgery. Methods: This study includes a systematic review using PubMed, MEDLINE, Cochrane, and Scopus. Data curation utilized Covidence software, with dual-reviewer screening and conflict resolution by a third party, focusing on publications with the full texts available. Results: The initial search yielded 1697 articles. Following title, abstract, and full-text screening, a total of 62 articles were included in this review. A total of 70.9% of included articles had moderate bias, with the rest having low risk of bias. The sample consisted of 2550 patients with an average age of about 20 years and an average follow-up of 16.8 months. The most employed procedure was Le Fort I osteotomy (99%). In terms of velopharyngeal function, there were notable increases in insufficiency and severity scores, with an average 63% worsening score from the baseline. That being said, patients experienced an average 33% improvement in speech articulation. Furthermore, the average horizontal movement was reported to be 6.09 mm with a subsequent relapse of 0.98 mm overall. Conclusions: This systematic review distills data from 62 articles and 2550 patients. It highlights the efficacy of orthognathic surgery in addressing oropharyngeal and aesthetic deficits. This study identifies relapse and velopharyngeal insufficiency as recurrent complications. These insights inform surgical refinement and patient counseling, laying a foundation for enhanced clinical protocols.

Angled channel retractor for sagittal split ramus osteotomy.

Protecting the adjacent soft tissues using a channel retractor prevents complications, such as excessive bleeding, during sagittal split ramus osteotomy. However, the saucer-shaped blade of the conventional channel retractor fits poorly into the posterior border of the mandibular ramus during medial osteotomy, which is typically performed parallel to the occlusal plane. Therefore, a novel channel retractor was developed with an adjusted blade bending angle, based on cephalometric data. The lateral cephalograms of 339 Japanese patients with jaw deformities were collected. Cephalometric landmarks were identified based on the definitions of the Downs-Northwestern analysis, and the acute angle between the occlusal and ramus planes was calculated. Based on the consistent mean and median occlusal ramus angles obtained, the blade was bent at 70° in the sagittal plane to fabricate the angled channel retractor. The engagement at the posterior border of the mandibular ramus during medial osteotomy enhances its stability. Furthermore, owing to the bending direction, the angled channel retractor used for medial osteotomy on one side can be used as a channel retractor for lateral osteotomy on the other side. The proposed angled channel retractor offers both stability and versatility for osteotomy manoeuvres.

Clinical validity and precision of deep learning-based cone-beam computed tomography automatic landmarking algorithm.

Purpose: This study was performed to assess the clinical validity and accuracy of a deep learning-based automatic landmarking algorithm for cone-beam computed tomography (CBCT). Three-dimensional (3D) CBCT head measurements obtained through manual and automatic landmarking were compared. Materials and Methods: A total of 80 CBCT scans were divided into 3 groups: non-surgical (39 cases); surgical without hardware, namely surgical plates and mini-screws (9 cases); and surgical with hardware (32 cases). Each CBCT scan was analyzed to obtain 53 measurements, comprising 27 lengths, 21 angles, and 5 ratios, which were determined based on 65 landmarks identified using either a manual or a 3D automatic landmark detection method. Results: In comparing measurement values derived from manual and artificial intelligence landmarking, 6 items displayed significant differences: R U6CP-L U6CP, R L3CP-L L3CP, S-N, Or_R-R U3CP, L1L to Me-GoL, and GoR-Gn/S-N (P<0.05). Of the 3 groups, the surgical scans without hardware exhibited the lowest error, reflecting the smallest difference in measurements between human- and artificial intelligence-based landmarking. The time required to identify 65 landmarks was approximately 40-60 minutes per CBCT volume when done manually, compared to 10.9 seconds for the artificial intelligence method (PC specifications: GeForce 2080Ti, 64GB RAM, and an Intel i7 CPU at 3.6 GHz). Conclusion: Measurements obtained with a deep learning-based CBCT automatic landmarking algorithm were similar in accuracy to values derived from manually determined points. By decreasing the time required to calculate these measurements, the efficiency of diagnosis and treatment may be improved.

Is minimally invasive approach to genioplasty predictable for mentolabial soft tissue? A retrospective cohort study.

INTRODUCTION: The aim of this study was to conduct a three-dimensional analysis of the effects on mentolabial soft tissues of three different orthognathic surgery protocols: bimaxillary surgery without genioplasty, bimaxillary surgery with conventional or minimally invasive genioplasty (MIS). MATERIALS AND METHODS: Pre-operative and post-operative CBCT were superimposed to quantify and ascertain the direction of mandibular movements, and soft tissue were analyzed to evaluate the hard to soft tissue ratio. Data from 97 consecutive patients were evaluated: 30 conventional genioplasty, 36 MIS and 31 no genioplasty. RESULTS: The impact of the surgical movements on the overlying soft tissues can be consider with stronger correlation in the group No Genioplasty in the whole mentolabial region, stronger correlation in labial and pogonion region in the MIS group and no stronger correlation in the conventional group. CONCLUSIONS: Sutures in the mentolabial region directly interfere with the postoperative impact of orthognathic surgery on soft tissues in mentolabial area, in both the vertical and horizontal directions. A smaller incision - consequently involving less detachment of soft tissues in the region - may promote a lower risk of chin ptosis, in addition to greater suspension of the musculature.