Orthognathic surgery: a significant tool for reassessment / La chirurgie orthognathique : un outil à ne pas oublier dans la réévaluation

Introduction: More than 15 years of experience in orthodontic-surgical collaboration has allowed the authors to identify some situations in which a new perspective is needed. Although it may seem easy to refer a patient to a maxillo-facial surgeon in cases of major dysmorphoses, this can lead to yet other dilemmas: a loss of results at the end of a developmental growth stage, an adult requesting a return to treatment after a camouflage orthodontic treatment or a non-cooperative child in an interceptive and preventive treatment phase. Then, a comprehensive process of reassessment becomes compulsory. Material and Method: In the form of an editorial, this article describes various cases encountered in the authors' practice. Discussion: The aim is not to point out the imperfections of our humanity, but simply to open our eyes to diagnostic elements that are missed, whether in the initial phase or during reassessment. Conclusion: As it is far from ideal to keep offering similar therapies that lead to the same pitfalls, it is time for a shift in the paradigm.

Introduction: Plus de 15 ans de recul en collaboration orthodontico-chirurgicale ont permis aux auteurs d'identifier un certain nombre de situations dans lesquelles un regard différent est devenu opportun. S'il est aisé d'orienter un patient vers un(e) chirurgien(ne) maxillo-facial(e) en cas de dysmorphoses majeures, les orthodontistes sont régulièrement confrontés à d'autres dilemmes : une perte de résultat en fin de croissance, un adulte demandeur d'une reprise après un traitement en compensation ou encore un enfant non-coopérant en phase interceptive. Une phase de réévaluation exhaustive devient alors nécessaire. Matériel et méthode: Sous la forme d'un éditorial, cet article expose différentes situations cliniques auxquelles les auteurs ont été confrontés lors de leur pratique. Discussion: Le propos n'est pas de pointer les imperfections de notre humanité mais seulement d'ouvrir les yeux sur des éléments diagnostiques qui échappent, que ce soit en phase initiale ou en réévaluation. Conclusion: Offrir une thérapeutique identique conduisant aux mêmes écueils n'est pas acceptable : il est temps de changer de paradigme.

Site and severity of facial asymmetry after bimaxillary surgery for class III deformity: a case-control study.

OBJECTIVES: The study aimed (1) to evaluate the site and severity of facial asymmetry in Class III patients before and after bimaxillary surgery, and (2) to identify the influence of initial severity and positional jaw asymmetry on residual facial asymmetry. MATERIALS AND METHODS: Preoperative and postoperative cone-beam computed tomography of 65 patients with Class III facial asymmetry who underwent bimaxillary surgery were evaluated. Five midline and 14 paramedian facial soft tissue landmarks were identified to assess facial asymmetry. The outcomes were compared to a control group consisting of 30 age- and gender-matched Class I subjects. The postoperative positional jaw asymmetry (i.e., shift, roll, yaw) of each osteotomy segment (maxilla, mandible, chin, ramus) was also measured. RESULTS: Before surgery, the asymmetry was more severe at the chin, middle and lower contour. Bimaxillary surgery effectively corrected facial asymmetry, particularly in achieving normalization of chin deviation. However, significant asymmetry persisted postoperatively in the middle and lower contour (p < 0.001 and p < 0.01, respectively), which was affected by the positional ramus asymmetry in the roll and shift. CONCLUSIONS: Deviation of the chin, middle and lower contour contributed significantly to overall facial asymmetry in Class III asymmetry. Despite normalization of the chin deviation after bimaxillary surgery, asymmetry persisted at the middle and lower contour, primarily as the result of insufficient correction of the positional ramus asymmetry. CLINICAL RELEVANCE: Understanding the residual asymmetry after bimaxillary surgery is important for minimizing deviation and optimizing the surgical planning for its correction.

Facial Asymmetry Caused by Mandibular Condylar Hyperplasia: A Two Center Study.

BACKGROUND: Condylar hyperplasia is a non-neoplastic overgrowth of the mandibular condyle. The disorder is progressive and causes gradual jaw deviation, facial asymmetry, and dental malocclusion. The only treatment capable of stopping hyperplastic growth is surgical condylectomy to remove the upper portion of the condyle containing the deranged growth center. When this procedure is conducted in proportion to the length of the healthy side it may also correct the jaw deviation and facial asymmetry. OBJECTIVES: To assess the degree to which condylectomy corrects the asymmetry and to determine the proportion of patients after condylectomy who were satisfied with the esthetic result and did not desire further corrective surgery. METHODS: We conducted a retrospective analysis of medical records of patients who underwent condylectomy that was not followed by corrective orthognathic surgery for at least 1 year to determine the degree of correction of chin deviation and lip cant. Patient satisfaction from treatment or desire and undergo further corrective surgery was reported. RESULTS: Chin deviation decreased after condylectomy from a mean of 4.8° to a mean of 1.8° (P < 0.001). Lip cant decreased after condylectomy from a mean of 3.5° to a mean of 1.5° (P < 0.001). Most patients (72%) were satisfied with the results and did not consider further corrective orthognathic surgery. CONCLUSIONS: Proportional condylectomy could be a viable treatment to both arrest the condylar overgrowth and achieve some correction of the facial asymmetry.

Correlation of Orthognathic Surgical Movements to Perception of Facial Appearance in Patients With Cleft Lip and Palate.

STUDY DESIGN: Cephalometric scans were compared before and after surgery to assess the degree of correction. Correlations between skeletal movements and survey outcomes were determined using multivariate regression analysis. OBJECTIVE: This study aims to identify relationships between subjective observer-reported improvements in esthetics and emotional appearance with specific surgical movements. METHODS: Ten patients at a single tertiary institution (average age: 18.1 ± 0.8), 9 males and 1 female, underwent orthognathic repair and had comprehensive cephalometric records. Standardized anterior posterior and lateral pre and postoperative photographs of patients were included in a survey to clinicians to assess noncognitive domains on a Likert Scale (1-10). CLEFT-Q was administered to gauge patient satisfaction in categories of appearance, speech, and quality of life. RESULTS: Per clinicians, multiple domains increased including facial attractiveness (4.1 ± 0.7 versus 7.3 ± 0.7, P < 0.001), friendliness (4.5 ± 0.4 versus 7.3 ± 0.5, P < 0.001), confidence (4.1 ± 0.4 versus 7.1 ± 0.4, P < 0.001), and recommendation for surgery decreased (8.9 ± 0.1 versus 3.6 ± 0.5, P < 0.001). Speech distress decreased with increased SNA and convexity, whereas Psychological and Social scores decreased with an increased ANB. Functional eating and drinking scores increased with maxillary depth. CONCLUSIONS: Orthognathic surgery improves many noncognitive domains in patients with cleft lip and palate as assessed by both patients and clinicians on all aspects of facial attractiveness and perception. These findings demonstrate objective bases of skeletal adjustments for perceived improvements in facial appearance and emotion.

Assessment of Masseter Volume and Postoperative Stability After Orthognathic Surgery in Patients With Skeletal Class III Malocclusion With Facial Asymmetry.

OBJECTIVE: This study aimed to evaluate the effect of orthognathic surgery on masseter volume in patients with skeletal Class III malocclusion with facial asymmetry and the effect of masseter volume on stability in orthognathic surgery. METHODS: This research studied 16 patients with Class III malocclusion with facial asymmetry who received combined orthodontic-orthognathic treatment and underwent craniofacial computed tomography (CT) before (T0), 2 weeks after (T1), and 6 months after (T2) surgery. Three-dimensional (3D) CT images were retrospectively analyzed, using 3D volume reconstruction to obtain the masseter volume and examine the impact of the masseter volume on stability in orthognathic surgery. RESULTS: A statistically significant difference ( P < 0.05) in the volume of the masseter was found up to 6 months after orthognathic surgery compared with the preoperative period, and the reduction in the masticatory muscle volume on the lengthened side is greater than on the shortened side ( P < 0.05). The volume of both masseters differed according to facial asymmetry, and the difference was significantly reduced after orthognathic surgery ( P < 0.05). During the period time (T1-T2), cephalometric maxillary marker points were not significantly different ( P > 0.05), and mandibular marker points were significantly anteriorly shifted ( P < 0.05). There was an association between the masseter volume and anterior shift of point B (R > 0.5, P < 0.05), the upward and anterior shifts of the gonion point differed between the lengthened and shortened sides ( P < 0.05). CONCLUSION: The size of the masseter becomes smaller 6 months after orthognathic surgery, and orthognathic surgery improves both bone and soft tissue symmetry. A larger sagittal relapse of mandibular setback occurred in patients with greater masseter volume. Considering these alterations may be helpful in planning orthognathic surgery.

Photographic Parameters in Three-Dimensional Facial Image Acquisition. A Scoping Review.

OBJECTIVE: Orthognathic surgery is a viable and reproducible treatment for facial deformities. Despite the precision of the skeletal planning of surgical procedures, there is little information about the relations between hard and soft tissues in three-dimensional (3D) analysis, resulting in unpredictable soft tissue outcomes. Three-dimensional photography is a viable tool for soft tissue analysis because it is easy to use, has wide availability, low cost, and is harmless. This review aims to establish parameters for acquiring consistent and reproducible 3D facial images. METHODS: A scoping review was conducted across PubMed, SCOPUS, Scientific Electronic Library Online (SciELO), and Web of Science databases, adhering to "Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews" guidelines. Articles presenting 3D facial photographs in the diagnostic phase were considered. RESULTS: A total of 79 articles were identified, of which 29 were selected for analysis. CONCLUSION: The predominant use of automated systems like 3dMD and VECTRA M3 was noted. User positioning has highest agreement among authors. Noteworthy aspects include the importance of proper lighting, facial expression, and dental positioning, with observed discrepancies and inconsistencies among authors. Finally, the authors proposed a 3D image acquisition protocol based on this research findings.

Determining the position of the lingula and the mandibular foramen using the antilingula in orthognathic surgery.

BACKGROUND: The antilingula located on the lateral surface of the mandibular ramus has been served as a surgical landmark for the mandibular foramen on the medial surface for decades. However, whether the antilingula truly represents the lingula which is the bony prominence overlapping the mandibular foramen, or the foramen itself, is still unclear. This study thus aimed to examine the position of the antilingula in relation to three reference points: the lingula, the anterior and the posterior borders of the mandibular foramen, as well as to the reference plane used in the inferior alveolar nerve block, and to the posterior border of the mandible. METHODS: This observational study was performed in 113 Thai dry mandibles. The antilingula were identified followed by transferring the reference points to the lateral surface. The distances from the antilingula to the reference points, the reference plane and the posterior border of the ramus were then measured. Chi-square test was calculated for side-dependency of the antilingula. Paired t-test was calculated for difference in measurements in left and right sides. RESULTS: The antilingula could be identified in 92.48% of the mandibles with 86.67 - 90.00% accuracy and 86.67% reliability. There was no significant difference in the presence of the antilingula on left and right sides (p = 0.801). Only 2.5% and 0.83% of the antilingula correspond to the lingula and the anterior border of the mandibular foramen, respectively. However, 85% of the reference points were located within 11 mm radius. The antilingula was found located 2.80 mm inferior to the reference plane and 16.84 mm from the posterior border of the ramus. CONCLUSIONS: The antilingula does not concur with the reference points on the medial surface. Our study also suggests that the safe area for vertical osteotomy is 11 mm posterior to the antilingula or at 30% of the length from the posterior border parallel to the occlusal plane. The use of more accurate techniques in localizing the mandibular foramen combined with the antilingula is more recommended than using the antilingula as a sole surgical guide.

Evaluation of pre- and postoperative nutrition and oral health-related quality of life in orthognathic surgery patients.

OBJECTIVE: Orthognathic surgery is a complex orofacial surgery that can significantly impact occlusal function and effect nutritional and quality of life parameters. This study aimed to evaluate alterations in dietary intake, chewing function, physical activity, and oral health-related quality of life of patients undergoing orthognathic surgery. RESEARCH METHODS AND PROCEDURES: In this prospective longitudinal study, the assessments were conducted at: preoperatively (T0) and postoperative first week (T1), second week (T2), first month (T3), and third month (T4) between May 2021 and March 2023. Sociodemographic questionnaire, 24-h dietary recall record, chewing ability form, International Physical Activity Questionnaire, and Oral Health Impact Profile-14 (OHIP-14) was applied at face-to-face interviews. RESULTS: Seventy eligible orthognathic surgery patients were evaluated, and 37 patients (52.8%) completed this study. Energy and fat intake significantly decreased from T0 to T1 (P < 0.001) and returned to basis by T4 (P = 0.015). Fiber intake was found to be lowest at T1 and T2 compared with other time points (P < 0.001). Chewing ability showed a deterioration and then improvement; however, patients still had difficulties chewing hard foods at T4. The OHIP-14 increased at T2 and T3 from T0 (P < 0.001 and P = 0.021, respectively) and showed a significant improvement at T4 (P < 0.05). CONCLUSION: The findings indicate a temporary decline in nutritional intake and chewing ability with subsequent recovery by the third month postsurgery. These changes, along with the trends in oral health-related quality of life, underscore the need for tailored nutritional and functional rehabilitation programs following orthognathic surgery.

An Enhanced Recovery After Surgery (ERAS) Protocol for Orthognathic Surgery Reduces Rates of Postoperative Nausea.

For many surgical procedures, enhanced recovery after surgery (ERAS) protocols have improved patient outcomes, particularly postoperative nausea and vomiting. The purpose of this study was to evaluate postoperative nausea following orthognathic surgery after the implementation of an ERAS protocol. This retrospective cohort study included patients between 12 and 35 years old who underwent orthognathic surgery at Boston Children's Hospital from April 2018 to December 2022. Patients with syndromes or a hospital stay greater than 48 hours were excluded from the study. The primary predictor was enrollment in our institutional ERAS protocol. The main outcome variable was postoperative nausea. Intraoperative and postoperative covariates were compared between groups using unpaired t tests and chi squared analysis. Univariate and multivariate regression models with 95% confidence intervals were performed to identify predictors for nausea. A P value<0.05 was considered significant. There were 128 patients (68 non-ERAS, 60 ERAS) included in this study (51.6% female, mean age 19.02±3.25 years). The ERAS group received less intraoperative fluid (937.0±462.3 versus 1583.6±847.6 mL, P ≤0.001) and experienced less postoperative nausea (38.3% versus 63.2%, P =0.005). Enhanced recovery after surgery status ( P =0.005) was a predictor for less postoperative nausea, whereas bilateral sagittal split osteotomy ( P =0.045) and length of stay ( P =0.007) were positive predictors for postoperative nausea in multivariate logistic regression analysis. Implementing an ERAS protocol for orthognathic surgery reduces postoperative nausea. Level of Evidence: Level III-therapeutic.

Orthognathic Surgery Trending: Retrospective Ten Years Cases Analysis in Nineveh Province, Iraq.

AIMS: The study aimed at analyzing patient's case sheets in regard to the incidence of skeletal discrepancy present in cases and its relation with the demographic profile of the sample. All these are chronicled for more than 10 years periods. METHODOLOGY: This is a retrospective study analysis of the orthognathic case sheets for more than 10 years period. The total numbers of patients are 678. Patient's case sheet was already prepared by the Multi-Disciplinary Team Orthognathic Surgery Clinic in Al-Salam Teaching Hospital, which is the only authorized committee in Nineveh Health Directorate. RESULTS: The highest age percentage is between (18 and 27 y/76%). Angle class III cases are the uppermost cases (36%) from the total. A significant P value is clear at the level ≤0.05 and ≤0.01 between surgery type and discrepancy in anterior segmental osteotomies (upper and lower) which is performed in bi-maxillary protrusion cases and Angle class II cases (0.01**). Similarly, anterior segmental osteotomies (upper jaw only) which are indicated in both open bite and Angle Class II cases documented as a statistically significant P value (0.02*). The positive correlation is shown in all variables with the disharmony or facial discrepancies. Esthetic and beauty as causes for treatment recorded more than function in relation to time series. CONCLUSION: This study documents that patients with skeletal class III accounted for the largest percentage (64%) in the study group. A high increase in patients number seeking treatment for their discrepancy is obvious with time from 2009 till 2022.

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).

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.

Changes in masseter muscle morphology after surgical-orthodontic treatment in patients with skeletal Class III malocclusion with mandibular asymmetry: The automatic masseter muscle segmentation model.

INTRODUCTION: This study evaluated the masseter muscle changes after surgical-orthodontic treatment in patients with a skeletal Class III malocclusion using automatic segmentation. METHODS: Images of 120 patients with skeletal Class III malocclusion were obtained and reconstructed at T0 (pretreatment), T1 (presurgery), and T2 (6-12-month postsurgery). The patients were divided into symmetrical and asymmetrical groups. The volume, major axis length, maximum cross-sectional area, horizontal cross-sectional area 5 mm above the mandibular foramen (CSAF), and orientation were calculated automatically. RESULTS: In the asymmetrical group, the volume and major axis length on the deviated side were lower than on the nondeviated side at T0, T1, and T2 (P <0.05). There were no significant differences in maximum cross-sectional area and CSAF bilaterally. The orientation was coronally more vertical and sagittally more forward on the deviated side (both P <0.001). In the symmetrical group, there were no significant bilateral differences at T0, T1, and T2. The volume, major axis length, and CSAF decreased, and the coronal orientation was more vertical on the nondeviated side at T2 than at T0 in both groups (P <0.05). The coronal plane orientation was more inclined on the deviated side at T2 than at T0 in the asymmetrical group (P <0.05). CONCLUSIONS: The smaller volume on the deviated side at T2 indicates the need for myofunctional training after surgery. The masseter muscle volume and the cross-sectional area did not recover to the preorthodontic levels. Studies with longer follow-up durations are needed to confirm these findings.

The change of state-trait anxiety among patients undergoing orthognathic surgery: A longitudinal study.

INTRODUCTION: This study aimed to assess state-trait anxiety level changes in Chinese patients with dentofacial discrepancies before and after orthognathic surgery and to explore the feasibility of developing a reference index for the preoperative screening of postoperative patients with high anxiety. METHODS: A total of 96 Chinese patients with dentofacial discrepancies who underwent orthognathic surgery were included in this study. Data were collected before orthognathic surgery and at 2 weeks (T2), 3 months, and 6 months (T4) after surgery using the State-Trait Anxiety Inventory. Receiver operating characteristic and linear regression analyses were performed to screen for preoperative indicators of postoperative high-state anxiety. RESULTS: State-trait anxiety levels in patients with dentofacial discrepancies decreased after surgery (F = 18.95, P <0.01; F = 6.90, P <0.01). Trait Anxiety Inventory can be used to screen patients with high-state anxiety from T2 to T4 (area under cover 95% confidence interval: T2, 0.74 [0.62-0.86]; 3 months, 0.79 [0.69-0.90]; T4, 0.77 [0.66-0.87], P <0.01), corresponding to cutoff values of 48.5, 46.5, and 45.5, respectively. CONCLUSIONS: All participants' state-trait anxiety levels improved after surgery compared with their preoperative levels. Preoperative trait anxiety levels can be used as a reference indicator to screen patients who may have high-state anxiety levels after orthognathic surgery. The creation of a screening scale will assist health care professionals to more pertinently help patients with high anxiety.

Comparison between one-jaw and two-jaw designs in virtual surgery planning for patients with class III malocclusion.

Orthognathic surgery is highly effective for treating maxillomandibular discrepancies in patients with class III malocclusion. However, whether one- or two-jaw surgery should be selected remains controversial. Our study aimed to evaluate quantitative differences between one-jaw and two-jaw surgical designs. In total, 100 consecutive patients with skeletal class III malocclusion who underwent orthognathic surgery with preoperative three-dimensional simulation between August 2016 and November 2021 were recruited. Based on the same final occlusal setup, a two-jaw surgery design and two types of one-jaw design were created. In total, 400 image sets, including preoperative images and three types of surgical simulation, were measured and compared. The one-jaw mandibular setback design led to improvement in most cephalometric measurements and facial symmetry. Although the one-jaw maxillary advancement design improved the ANB angle and facial convexity, it induced maxillary protrusion and reduced facial symmetry. Compared with the other designs, the two-jaw design provided significantly closer cephalometric measurements to the normative values, better symmetry, and less occlusal cant. Overall, the two-jaw design provided a quantitatively better facial appearance in terms of symmetry, proportion, and profile. Although an optimal surgical design necessitates thorough preoperative evaluation and a shared decision-making process, two-jaw surgery can be considered for improving overall facial esthetics and harmony.

Morpho-functional analysis of the temporomandibular joint following mandible-first bimaxillary surgery with mandible-only patient-specific implants.

The aim of this study was to evaluate condylar and glenoid fossa remodeling after bimaxillary orthognathic surgery guided by patient-specific mandibular implants. In total, 18 patients suffering from dentofacial dysmorphism underwent a virtually planned bimaxillary mandibular PSI-guided orthognathic procedure. One month prior to surgery, patients underwent a CBCT scan and optical scans of the dental arches; these datasets were re-acquired 1 month and at least 9 months postsurgery. Three-dimensional models of the condyles, glenoid fossae, and interarticular surface space (IASS) were obtained and compared to evaluate the roto-translational positional discrepancy and surface variation of each condyle and glenoid fossa, and the IASS variation. The condylar position varied by an average of 4.31° and 2.18 mm, mainly due to surgically unavoidable ramus position correction. Condylar resorption remodeling was minimal (average ≤ 0.1 mm), and affected skeletal class III patients the most. Later condylar remodeling was positively correlated with patient age. No significant glenoid fossa remodeling was observed. No postoperative orofacial pain was recorded at clinical follow-up. The procedure was accurate in minimizing the shift in relationship between the bony components of the TMJ and their remodeling, and was effective in avoiding postoperative onset of orofacial pain. An increase in sample size, however, would be useful to confirm our findings.

Evaluating changes in the condylar head after orthognathic surgery with or without articular disc repositioning: a systematic review.

Failures in orthognathic surgery are associated with different factors, including those related to untreated or undiagnosed preoperative temporomandibular joint (TMJ) disorders. This systematic review aimed to assess potential alterations in the condylar head following orthognathic surgery. A systematic search for randomised controlled trials and retrospective studies was performed. For inclusion in the review, studies had to meet the following eligibility criteria according to the PICO framework: Patients: patients with orthognathic deformity and temporomandibular dysfunction (or temporomandibular osteoarthritis); Intervention: patients submitted to orthognathic surgery concomitantly with TMJ disjunction; Control: patients undergoing only orthognathic surgery with or without presurgical data; and Outcome: changes in temporomandibular joint position and volume. Nine studies met all the inclusion criteria and were selected for qualitative analysis. The results of this review show that simultaneous articular disc repositioning and orthognathic surgery provide better results in patients with preoperatively diagnosed condylar osteoarthritic changes. In conclusion, condylar remodelling (resorption/deposition) and its extent are determined by the direction of condylar displacement during surgery. Other factors such as age are also associated with the development of condylar resorption.

Effect of Orthognathic Surgery On Pulp Blood Flow and Pulp Sensibility: A Prospective Control Trial.

INTRODUCTION: Orthognathic surgery has the potential to compromise the vitality of the teeth. This paper aims to assess changes in pulp blood flow (PBF) and pulp sensibility (PS) of the anterior dentition following orthognathic surgery and to assess the influence of the proximity of the surgical osteotomy on the PBF and/or PS. METHODS: Twenty-six patients undergoing orthognathic surgery (Le Fort I or bilateral sagittal split osteotomy [BSSO]) were compared to sixteen control patients treated by fixed appliances only using Laser Doppler flowmeter (LDF) and thermal testing (CO2 snow). Surgery patients were tested at T1 (presurgery), T2 (4-5 weeks postsurgery), T3 (3 months postsurgery), and T4 (6 months postsurgery). Control patients were tested at T1 (pretreatment), T2 (6 months posttreatment), T3 (12 months posttreatment), and T4 (18 months posttreatment). Differences between the maxilla and mandible were assessed. RESULTS: No differences in PBF or PS were recorded in the control group. In the surgery group, both jaws followed the same pattern after surgery, an initial decrease at T2 followed by a gradual recovery to pretreatment PBF levels with no significant difference between T1 versus T4 in both jaws. No difference in PBF was observed between the maxilla and mandible at any testing time interval. CONCLUSIONS AND CLINICAL IMPLICATIONS: PBF and PS of the anterior dentition was severely affected immediately postsurgery, followed by a gradual increase to full recovery. This pattern of recovery was exhibited in both jaws. A negative sensibility response or discoloration should not be seen as an indication of irreversible ischemic pulp changes. Monitoring for at least 6 months or using LDF as a confirmatory test is required before any irreversible endodontic treatment is to be considered.