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.

Effect of Induced Hypotensive Anesthesia and Normotensive Anesthesia on Intraoperative Blood Loss During Orthognathic Surgery: A Systematic Review.

Background: Orthognathic surgery involves significant bleeding from both soft tissues and bones due to rich blood supply to areas involved. In addition, limited access along with poor visibility and difficulty to isolate or ligate adds to the problem of bleeding during surgery. As a result, to counter drawbacks of intraoperative bleeding, method of induced hypotension stands out. Hypotensive anesthesia is a method through which blood pressure is decreased in a controlled manner. Various studies have been conducted that compared multiple methods to reduce intraoperative blood loss and improve visibility of surgical field. Hence, need for a systematic review to study the effects of hypotensive anesthesia on intraoperative blood loss, duration of the surgery and quality of surgical field. Methods: An electronic search was conducted to cumulate data from PubMed, Google scholar and institutional library from 2000 to 2020. In addition, bibliographies of included studies were hand searched to identify potentially eligible studies to append to the data and reach a conclusion. Results: Comparative study of the data available indicates that controlled hypotension during general anesthesia is safe for young healthy patients undergoing orthognathic surgeries. Conclusion: This information could be of key importance to aid in reducing intraoperative blood loss and which improves the observability of the surgical field; lessen the chances of need for blood transfusion; and eventually shorten the length of stay in hospital.

Positions of the Mandibular Foramen and Canal in Different Skeletal Classes and Implications for Bilateral Sagittal Split Osteotomy.

Objectives: To evaluate the positions of the mandibular foramen (MF) and mandibular canal (MC) between different skeletal classes to highlight the implications for bilateral sagittal split osteotomy (BSSO). Methods: A cross-sectional study was performed using cone-beam computed tomography on 90 patients classified into classes I, II and III. Linear measurements were performed on multiplanar reconstructions as follows: from the MF to the edge of the mandibular ramus (1), to the mandibular notch (2), to the ramus width (3) and to the occlusal plane (4); and from the MC to the alveolar crest (A), to the lower border of the mandible (B) and to the mandibular buccal cortical bone (C). Mandibular thickness (D), width (E) and height (F) of the MC were measured. Intra-class correlation coefficient (ICC) checked the reliability. Two-way ANOVA and Tukey's test were used to compare measurements and classes. Results: Linear measurements 2 presented a statistically significant difference between classes I and II. There was no statistically significant difference between the classes and measurements B, C, D, E and F. Linear measurements A were shorter in class III than in class II. Conclusions: Although most measurements suggest that the BSSO technique does not need to be modified for each skeletal class, measurements from the MF to the mandibular notch in class II and from the MC to the alveolar crest on distal of the second molars in class III could help surgeons to recognize critical regions.

Direction and Range of Condylar Positional Changes in the First-Year Post-surgical Orthodontics Interventions in Adult Patients with Skeletal Class III Deformity: A Systematic Review and Meta-analysis.

Objectives: Assess the available scientific literature regarding the direction and extent of condylar positional changes during the first year of post-surgical orthodontics interventions in class III patients. Materials and Methods: PubMed, Cochrane Library, Embase, and Google Scholar databases were searched up to March 2022 for studies involving the measurement of condylar positional changes after surgical treatment of Class III dentofacial deformity in adults with BSSO without or without Le Fort I osteotomies. The methodological index for non-randomized studies (MINORS) was utilized to assess the risk of bias and quality of non-randomized studies. Reporting of this review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Primary outcome was condyle positional changes between the following time points: T0: before treatment, T1: immediately post treatment, T2: 4, 6, or 9 months post treatment, T3: one year post treatment. Results: Nineteen studies were included in the systematic review. Eleven studies were deemed low quality, and the rest were of medium quality. The meta-analysis included 12 studies and showed statistically significant downward, outward positional changes at T1(Immediately after surgery). Inward Yaw rotation was significant at T1(1-4 month post-surgery) and T2(4-9 months post-surgery). Conclusion: Surgically induced condylar changes tend to go back to normal within the first year after surgery, except for condylar yaw rotations.

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.

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.

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.

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.

Variations of the Lingula and Mandibular Ramus in the Context of Sagittal Split Ramus Osteotomy: A Cone Beam Computed Tomography Study Supporting an Ethnic-Centric Approach to Orthognathic Surgery.

OBJECTIVES: To investigate the ethnic variations concerning the lingula and ramus of the mandible, with particular emphasis on sagittal split ramus osteotomy (SSRO) in orthognathic surgery. MATERIALS AND METHODS: This study examined Cone beam computed tomography (CBCT) scans from the Kenyan and Malay populations. Lingula morphology was classified into four categories. Morphometric measurements included lingula size, height above the occlusal plane, distance to the second mandibular molar, and distance from its apex to all four mandible borders. Regarding the ramus of the mandible, the thickness of each cortical plate, trabecular bone, and overall thickness were determined at two points. Furthermore, points of fusion of cortical plates were determined in both the vertical and horizontal planes. RESULTS: Among Kenyans, the triangular shape was most common (46.5%, n = 80 sides), while truncated was most common among Malays (34.4%, n = 57 sides). The overall mean size of lingula differed significantly between Kenyan (7.37 ± 2.19 mm) and Malay (4.14 ± 2.50 mm) populations (p<0.001). The lingula was more located postero-superiorly in Kenyans compared to Malays (p < 0.001). The mean distance from the distal aspect of the second mandibular molar to the lingula was 38.37 ± 4.98 mm among Kenyans, in contrast to 31.95 ± 0.03 mm among Malays (p < 0.001). The Malays exhibited a thicker mandible with a larger trabecular distance (5.99 ± 1.41 mm and 3.41 ± 1.29 mm, respectively) than Kenyans (5.28 ± 1.39 mm and 1.98 ± 0.98 mm, respectively) (p < 0.001). The points of fusion of the cortical plates differed significantly between Kenyans and Malays. CONCLUSION: This study focuses on two ethnic groups, Kenyans and Malays, and brings to light the ethnic-based differences in the position of the lingula and the dimensions of the mandibular ramus, both of which are essential considerations in orthognathic surgery. Preoperative consideration of such variations is warranted, potentially mitigating iatrogenic injuries and enhancing successful patient outcomes.

Changes in facial appearance alter one's sensitivity not only to the self but also to the outside world.

Introduction: Changes in facial appearance due to orthognathic surgery are known to improve a patient's postoperative quality of life, however, potential changes in cognitive function are unknown. This study examined the effects of changes in facial appearance due to orthognathic surgery on the sensitivity to self and to outside objects in patients with jaw deformities. Methods: Patients with jaw deformities (n = 22) and healthy controls (n = 30) were tested at 3 months preoperatively, at 1 month preoperatively, and at 1 month postoperatively to assess their impression of objects (positive, negative, and neutral pictures) and their evaluation of their own face and body. Results: The results showed that changes in facial appearance improved self-evaluation and increased their sensitivity to emotional objects even when the objects were identical. Furthermore, the improving rating for own face was associated with the sensitivity for objects. Discussion: The changes in facial appearance in patients may have helped to clear the sensitivity to these emotional objects. These findings may provide a new indicator of efficacy in orthognathic surgery.

Accuracy and clinical fit of milled versus rapid prototyped orthognathic surgical splints.

Three-dimensional (3D) printing has become an integral part of orthognathic surgery. However, there is a lack of studies evaluating accuracy of orthognathic surgical splints fabricated from subtractive milling versus additive 3D printing. The primary aim of this in-vitro study was to compare the differences in trueness between milled and 3D-printed splints, while the secondary aim was to compare the differences in clinical fit of these splints. A sample of eight patients was selected, and STL files of the final orthognathic surgical splint were used to fabricate three splints for each of the eight cases. The first splint was fabricated by subtractive milling (SM), whereas the second and third splints were 3D printed with Digital Light Processing (DLP) and Laser Stereolithography (SLA), respectively. Paired superimposition of scans was performed using a reference model. The clinical fit of the splints to the printed models was also assessed. The mean root mean square (RMS) deviations for the SM, SLA, and DLP were 0.11 ± 0.02, 0.16 ± 0.02 and 0.14 ± 0.02 respectively. The post-hoc analysis showed that the SM splints had the highest accuracy (p < 0.01). However, DLP splints showed the best clinical fit, followed by SM and SLA. In conclusion, splints fabricated by SM were more accurate than those fabricated by 3D printing, although this difference may not be clinically significant. The site, rather than the magnitude of the errors, may have a greater effect on the clinical usability of splints. In general, SM and DLP splints demonstrated a good clinical fit and were suitable for the fabrication of surgical splints.

Postoperative maxillary stability after Le Fort I osteotomy using a u-HA/PLLA system: three-dimensional analysis by surface superimposition based on virtual Le Fort I osteotomy.

The postoperative stability achieved with Le Fort I osteotomy (LFI) using bioabsorbable systems remains controversial. A new method - multipoint measurement method - was devised for detailed three-dimensional examination of postoperative stability following LFI, and the stability after LFI when using SuperFIXSORB-MX made of u-HA/PLLA was investigated. Thirty-one patients who underwent LFI using SuperFIXSORB-MX were evaluated retrospectively. The patients were divided into four malocclusion types: open bite, mandibular retrognathia, mandibular protrusion, and facial asymmetry. Seven maxillary reference points were measured three-dimensionally using computed tomography scans obtained preoperatively (T0), 4 days post-surgery (T1), and 1 year post-surgery (T2). Surgical changes (T1-T0) and the postoperative discrepancy (T2-T1) of the maxilla were analysed to evaluate postoperative stability by surface superimposition of the virtual LFI segments. Postoperative discrepancy was the largest for the facial asymmetry type, ranging from 0.75 ± 0.45 mm to 0.98 ± 0.52 mm in three-dimensional distance (minimum to maximum mean ± standard deviation values for the individual reference points). The relapse at U1 was 16% in the transverse axis, and the anterior nasal spine moved further upward by 17% of the amount of movement of the maxilla. Fixation with SuperFIXSORB-MX was considered to be within clinically acceptable limits.

Harmonizing soft tissue subnasale and chin position in a forehead-based framework: interracial commonalities and differences between Asian and Caucasian females.

OBJECTIVES: To establish a reference system for assessing the anteroposterior (A-P) position of the subnasal and lower-facial soft tissues for whole facial harmony. MATERIALS AND METHODS: Forty Asian and 40 Caucasian females with attractive profiles were selected as the "attractive" samples, with "ordinary" samples for comparison. Each profile was analyzed, and comparisons were made to reveal the interracial commonalities and differences. Esthetically essential parameters were established. An averaged attractive profile for each race was created by digital morphing and then modified into 30 variations based on combined variations of the esthetically essential parameters. Assessments were performed to investigate the esthetic ranges. RESULTS: A-P position of the subnasal and lower-facial landmarks harmonized with the forehead for female profile esthetics. In addition to balanced soft tissue subnasale (sSn)- and soft titssue pogonion (Pos)-to-forehead A-P relations, harmonizing lower-facial soft tissues to sSn was indispensable for profile attractiveness. sSn-to-glabella, Pos-to-glabella, and Pos-to-sSn A-P relations were esthetically essential. Perceived by orthodontists, the attractive Asian female profiles had sSn-to-glabella A-P relations ranging from 0.5 mm to 4.5 mm, Pos-to-sSn from -9.0 mm to -5.5 mm, and Pos-to-glabella from -8.5 mm to -1.0 mm. Compared with Asians, the attractive Caucasian female profiles had more anteriorly and widely distributed sSn relative to the forehead, wider ranges of Pos-to-sSn A-P relations, and more prominent chins. CONCLUSIONS: A reference system comprising sSn-glabella, Pos-sSn, and Pos-glabella horizontal distances was constructed for facial profile analysis. This system could aid treatment planning for surgical or orthopedic repositioning of the maxilla and chin.

Empowering surgeons: will artificial intelligence change oral and maxillofacial surgery?

Artificial Intelligence (AI) can enhance the precision and efficiency of diagnostics and treatments in oral and maxillofacial surgery (OMS), leveraging advanced computational technologies to mimic intelligent human behaviors. The study aimed to examine the current state of AI in the OMS literature and highlight the urgent need for further research to optimize AI integration in clinical practice and enhance patient outcomes. A scoping review of journals related to OMS focused on OMS-related applications. PubMed was searched using terms "artificial intelligence", "convolutional networks", "neural networks", "machine learning", "deep learning", and "automation". Ninety articles were analyzed and classified into the following subcategories: pathology, orthognathic surgery, facial trauma, temporomandibular joint disorders, dentoalveolar surgery, dental implants, craniofacial deformities, reconstructive surgery, aesthetic surgery, and complications. There was a significant increase in AI-related studies published after 2019, 95.6% of the total reviewed. This surge in research reflects growing interest in AI and its potential in OMS. Among the studies, the primary uses of AI in OMS were in pathology (e.g., lesion detection, lymph node metastasis detection) and orthognathic surgery (e.g., surgical planning through facial bone segmentation). The studies predominantly employed convolutional neural networks (CNNs) and artificial neural networks (ANNs) for classification tasks, potentially improving clinical outcomes.

Maxillofacial bone movements-aware dual graph convolution approach for postoperative facial appearance prediction.

Postoperative facial appearance prediction is vital for surgeons to make orthognathic surgical plans and communicate with patients. Conventional biomechanical prediction methods require heavy computations and time-consuming manual operations which hamper their clinical practice. Deep learning based methods have shown the potential to improve computational efficiency and achieve comparable accuracy. However, existing deep learning based methods only learn facial features from facial point clouds and process regional points independently, which has constrains in perceiving facial surface details and topology. In addition, they predict postoperative displacements for all facial points in one step, which is vulnerable to weakly supervised training and easy to produce distorted predictions. To alleviate these limitations, we propose a novel dual graph convolution based postoperative facial appearance prediction model which considers the surface geometry by learning on two graphs constructed from the facial mesh in the Euclidean and geodesic spaces, and transfers the bone movements to facial movements in dual spaces. We further adopt a coarse-to-fine strategy which performs coarse predictions for facial meshes with fewer vertices and then adds more to obtain more robust fine predictions. Experiments on real clinical data demonstrate that our method outperforms state-of-the-art deep learning based methods qualitatively and quantitatively.

Pharyngeal Airway Space Changes after Single Mandibular and Two-Jaw Surgery in Patients with Skeletal Class II Malocclusion.

Objective: To retrospectively evaluate the effects of single mandibular advancement (MA) and two-jaw surgery (2J-S) on the pharyngeal airway space (PAS) and hyoid position for the correction of skeletal Class II malocclusion. Methods: Eleven adult patients who underwent only MA surgery and twelve adult patients who underwent Le Fort I maxillary impaction-MA surgery (2-JS) were included in the retrospective study. A total of 46 cephalometric recordings obtained before (T1) and after treatment (T2) were examined. Craniofacial changes, area, and linear measurements of the pharyngeal airway and hyoid bone position were obtained in both groups. The Wilcoxon signed-rank test was used to evaluate time-dependent changes within groups. The Mann-Whitney U test was used to compare differences between groups. Results: Hyoid-Vert values increased significantly in both groups (MA, p<0.01; 2J-S, p<0.05); however, Hyoid-Hor values decreased significantly only in the 2J-S group (p<0.01). The anteroposterior dimensions of the airway increased in both groups, except for the PNS-P and PPS groups (p<0.01). Although a significant increase was observed in the nasopharyngeal area (A1) in the MA group (p<0.05), the decrease was found to be statistically significant in 2JG (p<0.01). Significant increases were found in the oropharyngeal (A2) and hypopharyngeal areas (A3) in both groups (p<0.01, p<0.05). Conclusion: Both surgical procedures for the correction of Class II malocclusion resulted in increased hypopharyngeal, oropharyngeal, and total airway measurements.

Establishment of Cephalometric Hard Tissue Profile among Bengali and Caucasian Populations for Orthognathic Surgery.

The study aimed to compare cephalometric hard tissue profile values and analysis between Bengali and Caucasian populations. The study included 100 individuals (50 males, 50 females) aged 18-35. Subjects having class I molar occlusions and well-balanced facial profiles were included in the study. Lateral cephalograms were taken with consent, and a prestructured proforma recorded relevant information and cephalometric measurements. Our study found increased posterior cranial base length in Bengali males and increased anterior cranial base length in both sexes. Bengali males had a less convex profile, while females had a more convex profile compared to Caucasians with similar mandibular features. Increased maxillary and mandibular incisor proclination was observed. Our findings indicate the necessity for separate norms for orthognathic surgery in normal ethnic Bengali adults.

Comparative analysis of 3D tomography based soft tissue rendering and Proface facial scanning systems in orthognathic surgery.

PURPOSE: This study aimed to investigate the linear and angular differences in the nasolabial soft tissue in patients who underwent bimaxillary orthognathic surgery using two different three-dimensional imaging methods. Furthermore, the advantages, disadvantages, and limitations of these methods were determined after comparing the data obtained from the imaging methods used in the study. MATERIALS AND METHODS: Preoperative (T0) and 6-months postoperative (T1) cone-beam computed tomography (CBCT) and three-dimensional facial scanning (3DFS) data from 22 patients who underwent maxillary advancement surgery were examined. The DICOM (Digital Imaging and Communications in Medicine) data (CBCT group) and ".obj" format images (3DFS group) of the patients were analyzed using Dolphin software (Dolphin Imaging®, Version 12, Chatsworth, CA, USA). The linear and angular soft tissue measurements were calculated after determining the reference anatomical landmarks for both groups. RESULTS: Measurements with CBCT and 3DFS imaging methods were compared at T0, T1, and all measurements (T0+T1). No statistically significant difference was observed between the CBCT and 3DFS groups for five measurements performed at T0 and T0+T1, but statistically significant differences were observed between the groups for the other seven measurements. There was no statistically significant difference between the CBCT and 3DFS groups for six measurements at T1, but there were statistically significant differences between the groups for the other six measurements. After reviewing the postoperative differences in the nasolabial soft tissue, a statistically significant increase in four linear and one angular measurement in the 3DFS group was observed, and there was a statistically significant increase in two linear and two angular measurements in the CBCT group. Upon comparison of postoperative differences in soft tissue alterations, no statistically significant difference between the 3DFS group and the CBCT group were observed in any of the soft tissue measurements. CONCLUSION: Orthognathic surgery has significant effects on nose width and upper lip morphology. Although both 3DFS and CBCT methods can be used to evaluate such effects, the results of the present study revealed differences in sensitivity and limitations between the two methods. Thus, surgical outcomes should be evaluated in consideration of the abovementioned parameters.

Mandible-First and Maxilla-First Sequencing in Virtual Surgical Planning for Orthognathic Surgery: Comparison of Planned and Actual Outcomes.

Background: Recent studies have shown that virtual planning for orthognathic surgery is an accurate and repeatable method. It is also a fact that surgical sequence can affect the results in terms of accuracy. Various studies stated that both approaches offer comparable results when properly planned and implemented; however, further clinical studies are still needed. This study aims to evaluate the effect of virtual surgical planning (VSP) on surgical outcomes and whether it is affected by mandible-first or maxilla-first approaches. Methods: This study analyzed data from 45 patients who underwent orthognathic surgery due to dentofacial deformity. Six of these patients underwent single-jaw orthognathic surgery, and 39 underwent bimaxillary orthognathic surgery (Maxilla-first group: 21, mandible-first group: 18). The displacements of specific landmarks were assessed by comparing preoperative and postoperative conventional computed tomographies with VSP data. Results: This study showed a statistically significant relationship between the measurements made with the 2 methods (r = .944; P = .0001). The fact that the intra-class correlation coefficient value is statistically significant and relatively high and that most of the differences in the Bland-Altman chart fall between the limits of compliance indicates a correlation between the virtual plan and surgical outcomes. In addition, in vertical measurements, the absolute mean difference of the B point and the Pogonion in the Maxilla-first group were statistically significantly higher than in the Mandible-first group (P = .038, P = .011). Conclusions: Our findings corroborate the high accuracy of the VSP reported in previous studies and also demonstrate that VSP with both maxilla-first and mandible-first sequencing achieves high accuracy in the sagittal and coronal planes. Although virtual planning significantly influences accurate surgical outcomes, it is not the sole determinant. Factors like condylar positioning and fixation methods can also impact the final results.