Orthognathic Surgical Procedures

This study aims to compare the effects of the Hunsuck and Posnick modifications of medial mandibular osteotomy on postoperative skeletal stability and relapse in patients undergoing orthognathic surgery. The study will evaluate whether the choice of medial osteotomy technique influences postoperative mandibular relapse.

This study aims to evaluate postoperative condylar remodeling in patients undergoing bimaxillary orthognathic surgery by comparing two different proximal segment positioning techniques used during mandibular osteotomy. Condylar remodeling will be assessed using preoperative, immediate postoperative, and 6-month postoperative computed tomography (CT) scans together with clinical findings.

The goal of this clinical trial is to find out whether using a splintless surgical approach improves the accuracy of maxillomandibular advancement (MMA) surgery for treating obstructive sleep apnea (OSA) in adults. The study will also look at the safety, functional outcomes, and cost-effectiveness of the splintless approach. The main questions it aims to answer are: Does the splintless approach lead to more accurate surgical movements of the jaws compared to the conventional splint-based method? What are the safety profile, functional outcomes, and cost-effectiveness of the splintless approach? Researchers will compare splintless MMA to conventional MMA. Patients will: Undergo MMA surgery using either the splintless or splint-based method; Attend regular follow-up visits as part of routine care; Complete questionnaires and undergo assessments at various time points; Receive one additional CT scan (24 months after surgery) and one overnight sleep study (60 months after surgery). Bedpartners of patients will: Complete questionnaires at various time points. This trial will help determine whether the splintless approach is a better, safer, and more effective alternative for treating OSA with MMA surgery.

The goal of this observational prospective cohort study is to learn about the natural course of central and mixed sleep apneas that develop after maxillomandibular advancement (MMA) surgery for obstructive sleep apnea (OSA) in adult patients. The main question it aims to answer is: Do central and mixed apneas resolve, partially resolve, or persist in the long term after MMA? Participants will: Undergo a first postoperative polysomnography (PSG) at 3-6 months after MMA (part of standard care). Be invited into the study if central/mixed apneas are detected (CMAI% \>25%). Undergo a second PSG at least 12 months after MMA (extra study procedure)

The goal of this randomized double-blinded controlled clinical trial is to determine whether piezosurgery can reduce complications and improve outcomes compared to conventional osteotomy techniques in patients undergoing bilateral sagittal split osteotomy (BSSO), with or without concurrent Le Fort I osteotomy (bimaxillary surgery). The main questions this study aims to answer are: * Does piezosurgery reduce inferior alveolar nerve impairment following BSSO compared to conventional techniques? * Does piezosurgery affect surgical duration, intraoperative blood loss, rates of bad splits, postoperative infections, costs, and environmental sustainability compared to conventional techniques? Researchers will compare BSSO performed with piezosurgery versus BSSO performed with conventional oscillating saw and burr techniques to see if piezosurgery leads to better sensory outcomes, reduced morbidity, and improved cost-effectiveness and sustainability. Participants will be: * Dutch or English-speaking adults aged 18-65 scheduled for BSSO or BIMAX surgery at Erasmus Medical Centre (Rotterdam) or St. Anna Hospital (Geldrop, Netherlands). * Exclusions include bone healing disorders, coagulation issues, facial trauma history, smoking, craniofacial anomalies, and planned simultaneous genioplasty. Participants will: * Undergo preoperative assessment of inferior alveolar nerve function (two-point discrimination test, validated questionnaire). * Be randomized into: * Intervention group: BSSO performed entirely using piezosurgery. * Control group: BSSO performed with conventional burr and saw techniques. * Have their surgery performed by experienced maxillofacial surgeons following standardized protocols. * Have operative time and blood loss recorded during surgery. * Be followed up at 1 week, 3 months, 6 months, and 1 year for nerve function, sensory recovery, and infection assessment. * Complete postoperative questionnaires on sensory changes at 3 months and 1 year. * Have surgical outcomes evaluated by blinded examiners. * Contribute to a life cycle cost analysis (LCC) and life cycle assessment (LCA) comparing equipment cost, maintenance, energy use, waste generation, and environmental impact between techniques.

The goal of this clinical trial is to learn whether using three dimensional (3D)-printed anatomical models improves the informed consent process for participants undergoing orthognathic surgery. The trial also explores how these models affect participants understanding, anxiety, satisfaction, and communication with the surgeon. The main questions it aims to answer are: * Do 3D-printed anatomical models improve participants understanding of their jaw condition and the surgical procedure? * Do they reduce participants anxiety before surgery? * Do they enhance overall participants satisfaction and the physician-patient relationship? Researchers compares participants who received standard two dimensional (2D) imaging and verbal explanations with those who received the same information plus 3D-printed jaw models. Participants: * Scheduled for double- or triple-jaw orthognathic surgery * Randomly assigned to receive either traditional 2D education or the 3D-printed model intervention * Complete a validated questionnaires assessing understanding, anxiety, satisfaction, and doctor-patient communication

This study is a retrospective analysis that evaluates the accuracy of 3D soft tissue simulation in bimaxillary orthognathic surgery for Class III dentofacial deformities. The study integrates segmented 3D facial conformation meshes and regional aesthetic subunits to enhance soft tissue prediction accuracy. Key Aspects of the Study: Study Design: Retrospective analysis based on existing CBCT scans of patients who have undergone maxillary advancement and mandibular setback surgery. Objective: To assess the accuracy of soft tissue predictions using Dolphin software in different facial regions, particularly in midline vs. lateral regions. Methodology: .CBCT superimposition using voxel-based registration. .Soft tissue surface analysis via generic mesh conformation and dense correspondence analysis. .Error assessment in X, Y, Z dimensions rather than Euclidean distance. .Color-coded maps for visualizing prediction accuracy. Clinical Relevance: The study aims to refine 3D prediction models for orthognathic surgery planning, making them more precise and reliable. Key innovation: Modifying the aesthetic unit segmentation approach for a clinically and statistically relevant assessment of soft tissue changes. Findings will contribute to improving surgical outcome predictability and optimizing treatment planning in maxillofacial surgery. Ethical Considerations: No patient recruitment; the study relies solely on existing anonymized CBCT scans. Ethical approval and waiver of informed consent will be sought from the Institutional Review Board (IRB). This research aligns with modern advancements in 3D facial prediction technology, aiming to enhance precision and clinical applicability in orthognathic surgery.

Assessment of the incidence of Body dismorphic disorder in a population candidated to orthognathic surgery

The purpose of this study is to evaluate the efficacy and safety of using high-purity magnesium bone plates and screws for internal fixation in jaw surgery. The investigators aim to assess whether these biodegradable magnesium devices promote normal bone healing and functional recovery while ensuring the safety of patients undergoing dentoalveolar surgery, fracture fixation, orthognathic surgery, or craniofacial reconstruction. The hypotheses are: 1. High-purity magnesium bone plates and screws are effective in bone fixation, promoting normal bone healing and functional recovery in jaw surgery. 2. High-purity magnesium bone plates and screws are safe in jaw surgery in terms of local side effects and systemic safety. Participants will undergo jaw surgery based on the clinical indications. High-purity magnesium bone plates and screws will be used for internal fixation during the surgical procedure. Participants will be followed up at 1 week, 3 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years after surgery to assess wound healing, functional recovery, and any side effects. If any side effects occur or deemed necessary, participants may be followed up for a longer period. During postoperative follow-up visits, X-ray or CBCT/CT imaging will be conducted routinely or when clinically indicated.