Volumetric evaluation of osteotomy gap following mandibular bilateral sagittal split osteotomy using a novel semi-automated approach: a pilot study.

OBJECTIVES: To establish an analysis pipeline for the volumetric evaluation of the osteotomy site after bilateral sagittal split osteotomy (BSSO). PATIENTS AND METHODS: Cone-beam computed tomography (CBCT) was performed before, directly after BSSO, and 6-12 months after surgery. Image segmentations of each osteotomy gap data set were performed manually by four physicians and were compared to a semi-automatic segmentation approach. RESULTS: Five patients with a total of ten osteotomy gaps were included. The mean interclass correlation coefficient (ICC) of individual patients was 0.782 and the standard deviation 0.080 when using the manual segmentation approach. However, the mean ICC of the evaluation of anatomical sites and time points separately was 0.214, suggesting a large range of deviation within the manual segmentation of each rater. The standard deviation was 0.355, further highlighting the extent of the variation. In contrast, the semi-automatic approach had a mean ICC of 0.491 and a standard deviation of 0.365, which suggests a relatively higher agreement among the operators compared to the manual segmentation approach. Furthermore, the volume of the osteotomy gap in the semi-automatic approach showed the same tendency in every site as the manual segmentation approach, but with less deviation. CONCLUSION: The semi-automatic approach developed in the present study proved to be valid as a standardised method with high repeatability. Such image analysis methods could help to quantify the progression of bone healing after BSSO and beyond, eventually facilitating the earlier identification of patients with retarded healing.

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

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

Do facial soft tissue thicknesses change after surgeries correcting dental malocclusions? An intra- and inter-patient statistical analysis on soft-tissue thicknesses in BSSO + LFI surgeries.

OBJECTIVES: The aim of this study was to analyse changes in facial soft tissue thickness (FSTT) after corrective surgeries for dental malocclusion. The correlation between body mass index (BMI) and sex of patients and their FSTT before undergoing surgery was analysed. MATERIALS AND METHODS: Cone beam computed tomography of seventeen patients that underwent Le Fort I osteotomy in combination with bilateral sagittal split osteotomy were collected. Hard and soft tissue landmarks were selected basing on the interventions. FSTT were computed, and measurements from pre- to post-operative were compared. The relationship between FSTT, sex, and BMI was investigated. RESULTS: Considering the comparison between pre- and post-operative measurements, any significant difference emerged (p > .05). The Pearson's correlation coefficient computed between BMI and the FSTT (pre-operative) showed a correlation in normal-weight patients; the region-specific analysis highlighted a stronger correlation for specific landmarks. Higher median values emerged for women than for men; the subset-based analysis showed that women presented higher values in the malar region, while men presented higher values in the nasal region. CONCLUSIONS: The considered surgeries did not affect the FSTT of the patients; differences related to BMI and sex were found. A collection of FSTT mean values was provided for twenty landmarks of pre- and post-operative of female and male subjects. CLINICAL RELEVANCE: This exploratory analysis gave insights on the behaviour of STT after maxillofacial surgeries that can be applied in the development of predictive methodologies for soft tissue displacements and to study modifications in the facial aspect of the patients.

Distribution of orthognathic surgery among the Swedish population: a retrospective register-based study.

OBJECTIVE: The aim of this study was to provide a nationally representative assessment of orthognathic procedures performed in hospitalised patients in Sweden and study regional differences in prevalence, demographic parameters and hospitalisation time. MATERIAL AND METHODS: From the Swedish National Board of Health and Welfare's register, all the patients undergoing orthognathic surgery between 2010 and 2014 were identified. Outcome variables were categorised into: (1) Surgical methods and regional distribution (2) Demographic variations (3) Hospitalisation time. RESULTS: The population-prevalence-rate of orthognathic procedures over the 5-year period was 6.3 (SD 0.4) per 100,000 persons, a regional difference in the prevalence was found. Most common were Le Fort I osteotomies (43.4%) and bilateral sagittal split osteotomies (41.6%), 39% of the patients had bimaxillary surgery. The majority of the surgery was performed in the age group 19-29 (68.8%). The mean hospital stay was 2.2 days (SD = 0.9, range 1.7-3.4). A significant regional difference (p ≤ 0.001) was found in hospitalisation time for single-jaw versus bimaxillary surgery. CONCLUSIONS: Regional differences in the distribution of orthognathic surgery and demographic variations were found in Sweden in 2010-2014. The underlying causes of variations are still unknown and request further investigation.

Prevalence of Temporomandibular Disorders in Orthognathic Surgery patients: A systematic review conducted according to PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions.

BACKGROUND: Orthognathic surgery is done to treat a variety of dentofacial abnormalities, but a wide gap still remains on how it can result in temporomandibular joint dysfunction (TMD). The primary goal of this review was to assess the effects of various orthognathic surgical techniques on the emergence or exacerbation of TMJ dysfunction. METHODS: A comprehensive search was conducted across several databases using Boolean operators and MeSH keywords related to temporomandibular joint disorders (TMDs) and orthognathic surgical interventions, with no limitation on the year of publication. Two independent reviewers screened the identified studies based on predetermined inclusion and exclusion criteria, followed by a risk of bias assessment using a standardised tool. RESULTS: Five articles were considered for inclusion in this review. A greater number of females opted for surgical options than their male cohorts. Three studies were of prospective design, 1 of retrospective and 1 of observational type. Mobility on lateral excursion, tenderness on palpation, arthralgia and popping sounds were the TMD characteristics that showed significant differences. Overall, orthognathic surgical intervention did not show an increase in TMD signs and symptoms as compared to nonsurgical counterparts. CONCLUSION: Though orthognathic surgery reported greater cases of some TMD symptoms and signs as compared to the nonsurgical cohorts in four studies, the conclusive evidence is debatable. Further studies are recommended with a longer follow-up period and greater sample size to determine the impact of orthognathic surgery on TMJ.

POST-SURGICAL NEUROSENSORY DYSFUNCTION OF INFERIOR ALVEOLAR NERVE IN BILATERAL SAGITTAL SPILT OSTEOTOMY OF THE MANDIBLE USING SAW VERSUS PIEZOTOME: A SYSTEMATIC REVIEW AND META-ANALYSIS.

PURPOSE: The purpose of this systematic review was to compare neuro-sensory dysfunction incidence between saw and piezotomes in patients requiring bilateral sagittal split osteotomy. METHODS: Searches were performed electronically in 4 databases (PubMed, LILACS, Cochrane Library, and grey literature) up to September 2020 and manually to identify studies addressing the subject. Randomized and non-randomized clinical trials were included. RESULTS: Six studies met the eligibility criteria with a total number of 284 participants. The risk of bias assessment for randomized clinical trials was high, and for non-randomized clinical trials was critical and serious. Regarding inferior alveolar neuro-sensory dysfunction, the meta-analysis showed no significant difference between saw and piezotome 1 week [RR = 0.99, 95% CI (0.90, 1.08) P = 0.79], and 3 months [RR = 0.39, 95% CI (0.09, 1.75) P = 0.22], post-operatively. CONCLUSIONS: For patients requiring bilateral sagittal split osteotomy, piezotomes seem to offer no advantage over conventional saws regarding the incidence of neurosensory disturbance. Follow-up periods longer than 3 months may reveal faster physiologic regain of sensations. They seem to be safer than conventional saws regarding blood loss. However, proper training for using the device is mandatory, while considering the longer operating time required. Further RCTs are still recommended to improve the level of evidence.

Maintaining the space between the mandibular ramus segments during bilateral sagittal split osteotomy does not influence the stability.

BACKGROUND/PURPOSE: Three-dimensional computer-assisted orthognathic surgery allows to simulate the space between the mandibular ramus segments, i.e. intersegmental gap, for the correction of facial asymmetry. The purposes of the study were to estimate the screws- and mandible bone-related changes from the early postoperative period to the period after the debonding and to measure the association between the intersegmental gap volume and the screws- and mandible bone-related changes. METHODS: This cone-beam computed tomography (CBCT)-assisted retrospective study assessed the stability of the bicortical positional screw fixations in maintaining the space between the mandibular ramus segments after bilateral sagittal split osteotomy in correction of 31 patients with malocclusion and facial asymmetry. The primary predictor variable was the CBCT-based intersegmental gap volume at early postoperative period (T1). The primary outcome variables were CBCT-based screws- and bone-related measurement changes between the T1 and T2 (at debonding) periods. RESULTS: No significant differences were observed in screws-related linear and angular measurements between T1 and T2 virtual models. Some of mandible bone-related linear and angular measurements had significant differences (P < 0.05) between the T1 and T2 images, but with no clinical repercussion such as need of revisionary surgery. The gap volume and the screws- and bone-related changes had no significant correlations. CONCLUSION: This study contributes to the multidisciplinary-related literature by demonstrating that the bicortical positional screws-based fixation technique in maintaining the three-dimensional-simulated space between the mandibular ramus segments is a stable and clinically acceptable option for correction of facial asymmetry associated with malocclusion, regardless of intersegmental gap size.

Treatment decision-making for a post-traumatic malocclusion in an elderly patient: A case report.

Traumatic dental injuries in elderly patients are a rising trend due to demographic and social changes of the population. Older dentulous patients in good health have become increasingly common. The development of a post-traumatic malocclusion is a common sequela resulting from mandibular condyle fracture, as in the case reported in this paper. The decision-making process led the authors to rule out conservative treatment options and to perform orthognathic surgery on an 81-year-old patient, an unprecedented report in the literature. At one-year follow-up, prophylactic therapy, a specific surgical technique, and osteotomy fixation have restored the occlusion to the pre-traumatic condition.

Anterior open bite - diagnostics and therapy.

An anterior open bite (AOB) is an occlusal disorder that causes the patient both an aesthetic and functional handicap. The lower third of the face is disproportionately larger. Patients are unable to properly occlude with the anterior part of dental arch and occlusion only happens in the premolar and/or molar regions. An anterior open bite may be the result of anatomical anomalies. Long term stability as well as an immediate outcome of the surgery depends on the choice of a suitable treatment strategy. In this article, we review options of AOB treatment, from classical orthodontic treatment to current combined orthodontic and surgical approach with a benefit of an anchor system.

Condylar position and mandibular function after bilateral sagittal split osteotomy.

AIM: The purpose of this retrospective study was to perform an evaluation of postoperative positional changes of the condyle and mandibular function after bilateral sagittal split osteotomy (BSSO) with manual proximal segment positioning. PATIENTS: 45 patients were divided into the 2 groups ‒ G1 (advancement ‒ 14 patients) and G2 (setback - 31 patients). Rigid internal fixation screws were utilized in all cases. Inclusion criteria were only BSSO, no TMJ symptoms preoperatively and age 18 or older. RESULTS: The differences between pre- and postoperative condyle position were evaluated using measurements taken from preoperative CT scans and compared to CT scans made a minimum of 6 months postoperatively. The positional changes in both the axial and sagittal planes were measured and compared. The recovery of mandibular function was evaluated by measuring maximal interincisal opening (MIO). The results revealed that condylar positional changes after BSSO in both groups were minimal and not significantly different for all three dimensions measured. The recovery of mandibular function was faster in the group G2 than in the group G1. Mandibular function reached almost preoperative level in 6-12 months postoperatively in both groups. CONCLUSION: The results demonstrated that following BSSO, only insignificant condylar displacement and functional changes occurred within 6 to 12 months postoperatively (Tab. 4, Fig. 2, Ref. 47).

Skeletal Stability After Mandibular Counterclockwise Rotational Advancement for Correction of Skeletal Class II Deformity-A Systematic Review and Meta-analysis.

OBJECTIVES: The aim of this systemic review was to compare surgical and postsurgical changes in the mandible after bilateral sagittal split osteotomy (BSSO) with counterclockwise (CCW) rotational advancement. A review of the current available dental literature regarding skeletal stability after mandibular CCW rotational advancement for skeletal Class II deformity was performed using a qualitative and quantitative analysis (meta-analysis). MATERIAL AND METHODS: Five databases were searched: PubMed, MEDLINE (Ovid), Science Direct, Scopus, and Web of Science. The systematic review and meta-analysis addressed the stability of BSSO CCW rotational advancement and the effect of the amount of CCW rotation on skeletal stability after BSSO advancement. Meta-analysis was performed only for studies reporting point B position in mm or mandibular plane angle in degrees before and after surgery and at follow-up. RESULTS: The database search resulted in 284 articles after removal of duplicates, and an additional 3 articles were included from hand searches of the bibliographies of the selected articles and relevant reviews. Eight studies were included in the systematic review; all were retrospective case series, and all used rigid fixation. Only 1 study was of medium quality; all other studies were of low quality. Meta-analysis of 3 studies revealed a mean forward movement of 7.6 mm at point B (95% confidence interval [CI], 4.07 to 11.4), a mean downward movement of 2.6 mm (95% CI, -0.66 to 5.84), and a mean CCW rotation of mandibular plane of 4.3° (95% CI, -6.34 to -2.19) during surgery. After surgery, point B showed a mean backward movement of -0.18 mm (95% CI, -1.30 to 1.14), a mean upward movement of -0.5 mm (95% CI, -3.00 to 1.98), and a mean clockwise rotation of 0.1° (95% CI, -1.76 to 1.91). CONCLUSIONS: Meta-analysis showed mandibular CCW rotational advancement is a stable procedure, both horizontally and vertically. However, the conclusions are far from robust due to the small sample size and poor quality of the reviewed studies.

Bilateral sagittal split osteotomy-parameters and correlations of postoperative pain management.

OBJECTIVES: Postoperative pain management is of utmost interest for patients undergoing orthognathic surgery. Currently, there is a lack of information regarding process and outcome parameters of postoperative pain management after bilateral sagittal split osteotomy. MATERIALS AND METHODS: In a prospective clinical study, 31 adults were evaluated on the first postoperative day following bilateral sagittal split osteotomy using the standardized questionnaire of the Germany-wide project Quality Improvement in Postoperative Pain Management (QUIPS). It allows a standardized assessment of patients' characteristics, pain parameters, outcome, and pain therapy process parameters. RESULTS: Pain management consisted mainly of premedication with midazolam, sufentanil, and metamizol intraoperatively; piritramide in the recovery room; and metamizol and tramadol on ward. Twenty patients (64.5%) showed inadequate pain management with pain levels ≥4. Patients receiving tramadol as opioid on ward presented significantly higher maximum pain levels (p = .037). Significantly lower satisfaction with postoperative pain intensity (p > .001) and significantly higher desire for additional pain medication (p = .023) were detected, when duration of surgery was above the median of 107.5 min. CONCLUSIONS: Inadequate pain management on the first postoperative day following bilateral sagittal split osteotomy was widespread on our ward. QUIPS helped us to identify it and thereby gave us the possibility to improve the situation. Prolonged duration of surgery seems to be a predictor of an elevated postoperative pain medication demand. CLINICAL RELEVANCE: Only the establishment of an ongoing monitoring of postoperative pain management can help to reduce or even avoid inadequate postoperative pain management. In accordance to the existing literature, we found inadequate postoperative pain management more widespread than thought.

The variable position of the inferior alveolar nerve (IAN) in the mandibular ramus: a computed tomography (CT) study.

INTRODUCTION: This study was designed to quantify the important anatomical landmarks and the path of the inferior alveolar nerve (IAN) within the human mandibular body and ramus, in particular with reference to the bilateral sagittal split osteotomy (BSSO). MATERIALS AND METHODS: Four hundred and eleven CT scans were studied, 299 of these were involved in determining the position of lingula; and 230 were involved in determining the course of IAN in the mandibular molar region, namely from the mesial of the mandibular first molar to the distal of the mandibular second molar; 118 were involved with both measurements. RESULTS: On average, the lingula was located 17.0 ± 2.2 mm from the external oblique ridge; 11.6 ± 2.0 mm from the internal oblique ridge; 17.2 ± 2.7 mm from the sigmoid notch; and 15.6 ± 1.9 mm from the posterior border of the mandible. The course of the IAN in the mandibular molar region was found to descend vertically from the distal of the mandibular second molar (7) to reach its lowest point between the first and second molars (6 and 7), and then ascend towards the mesial of the first molar (6). Horizontally, the IAN was found to traverse medially between the distal of the 7 and the middle of the 7, and then changes its path laterally towards the mesial of the 6. CONCLUSION: Precise knowledge of the individual's position of the IAN will help surgical planning.

Neurosensory deficit following mandibular sagittal split osteotomy: A comparative study between positional screws and miniplates fixation.

This retrospective study compared the incidence of long-term inferior alveolar nerve injury for positional screws and miniplate fixation of bilateral sagittal split osteotomies carried out in 2 hospitals in Scotland. The study involved a mixture of mandibular setback and advancement surgery. The outcome of neurosensory deficit (NSD) was solely based on subjective assessment by the surgeons and patients' reported alteration in sensation. Numbness, tingling and any alterations in sensation beyond 6 months were considered long-term inferior alveolar nerve injury. This study was conducted on 28 sagittal split osteotomies (group 1) which were fixed with three upper border fixation screws and 36 sagittal split osteotomies (group 2) which were fixed with upper border sliding plate. The reported and documented neurosensory deficits were analysed. The difference in the number of cases of long-term inferior alveolar nerve injury between the 2 methods was 10.3%; the 95% confidence interval for the difference was [-2.94 to 23.5], p = 0.1612. Upper border plate was associated with more long-term NSD but there is insufficient evidence to prove that one method was more superior to the other. The need for a prospective randomized trial was highlighted.

Changes in posterior airway space and hyoid bone position after surgical mandibular advancement.

OBJECTIVE: To evaluate cephalometric changes in posterior airway space (PAS) and in hyoid bone distance to mandibular plane (MP) 1-3 years after bilateral sagittal split osteotomy (BSSO). MATERIAL AND METHODS: The sample consisted of 36 females and 16 males who underwent mandibular advancement by BSSO. To observe sagittal changes in PAS and in hyoid bone distance to MP both pre- and postoperative cephalograms were analyzed using WinCeph® 8.0 software. For the statistical analyses paired T-test and multivariate logistic regression models were used. RESULTS: By the surgical-orthognathic treatment the sagittal dimension of PAS showed variable changes but it mainly diminished when the mandibular advancement exceeded 6 mm. In most cases the hyoid bone moved superiorly by BSSO. Logistic regression models showed that males, patients with narrow PAS at the baseline, and those with counterclockwise rotation of the mandible by the treatment gained more increase in PAS. However, an increase in sagittal PAS dimension tended to relapse over time. Concerning the movement of the hyoid it was found that the more PAS increased the less hyoid moved superiorly. In males the change in hyoid position was more obvious than in females. CONCLUSION: Males, patients with narrow PAS at the baseline, and those whose mandible moved in the counterclockwise direction with moderate advancement gained more retrolingual airway patency by BSSO.

An accurate bimaxillary repositioning technique using straight locking miniplates for the mandible-first approach in bimaxillary orthognathic surgery.

Bimaxillary orthognathic surgery has been widely performed to achieve optimal functional and esthetic outcomes in patients with dentofacial deformity. Although Le Fort I osteotomy is generally performed before bilateral sagittal split osteotomy (BSSO) in the surgery, in several situations BSSO should be performed first. However, it is very difficult during bimaxillary orthognathic surgery to maintain an accurate centric relation of the condyle and decide the ideal vertical dimension from the skull base to the mandible. We have previously applied a straight locking miniplate (SLM) technique that permits accurate superior maxillary repositioning without the need for intraoperative measurements in bimaxillary orthognathic surgery. Here we describe the application of this technique for accurate bimaxillary repositioning in a mandible-first approach where the SLMs also serve as a condylar positioning device in bimaxillary orthognathic surgery.

Evaluation of mandibular condyle position in Class III patients after bimaxillary orthognathic surgery: A cone-beam computed tomography study.

Objective: This retrospective study evaluated the mandibular condyle position before and after bimaxillary orthognathic surgery performed with the mandibular condyle positioned manually in patients with mandibular prognathism using cone-beam computed tomography. Methods: Overall, 88 mandibular condyles from 44 adult patients (20 female and 24 male) diagnosed with mandibular prognathism due to skeletal Class III malocclusion who underwent bilateral sagittal split ramus osteotomy (BSSRO) and Le Fort I performed using the manual condyle positioning method were included. Cone-beam computed tomography images obtained 1-2 weeks before (T0) and approximately 6 months after (T1) surgery were analyzed in three planes using 3D Slicer software. Statistical significance was set at P < 0.05 level. Results: Significant inward rotation of the left mandibular condyle and significant outward rotation of the right mandibular condyle were observed in the axial and coronal planes (P < 0.05). The positions of the right and left condyles in the sagittal plane and the distance between the most medial points of the condyles in the coronal plane did not differ significantly (P > 0.05). Conclusions: While the change in the sagittal plane can be maintained as before surgery with manual positioning during the BSSRO procedure, significant inward and outward rotation was observed in the axial and coronal planes, respectively, even in the absence of concomitant temporomandibular joint disorder before or after the operation. Further long-term studies are needed to correlate these findings with possible clinical consequences.

Orthognathic Surgery in Patients With Von Willebrand's Disease: A Report of Four Cases and Literature Review.

Von Willebrand's disease (VWD), characterized by quantitatively or qualitatively abnormal von Willebrand factor (VWF), is the most common inherited bleeding disorder. There is limited evidence of treatment using orthognathic surgery in patients with VWD. This report focuses on four patients with VWD who underwent orthognathic surgery and received Factor VIII/VWF concentrates (Confact F) preoperatively. One patient with type 3 (severe) VWD underwent delayed extubation owing to laryngeal edema and exhibited epistaxis thereafter. No perioperative complications were observed in any of the other patients. Two of the four patients were diagnosed with VWD during preoperative screening. Most young adults do not experience general anesthesia and, therefore, may not have undergone blood tests at a hospital. Thus, preoperative screening and adoption of a multidisciplinary approach to orthognathic surgery is important in patients with bleeding disorders such as VWD. Close communication between anesthetists, surgeons, and hematologists is essential to ensure effective management during the perioperative period.

Bilateral sagittal split osteotomy with or without concomitant removal of third molars: a retrospective cohort study of related complications and bone healing.

PURPOSE: To carry out a comparative evaluation of the intra- and postoperative complications, and bone healing, following bilateral sagittal split osteotomy (BSSO) with or without concomitant removal of third molars. MATERIAL AND METHODS: A retrospective analysis was performed of two cohorts subjected to BSSO with the intraoperative removal of third molars (test group) versus the removal of third molars at least 6 months prior to BSSO (control group), comprising at least 1 year of clinical and radiographic follow-up. Partially or completely erupted third molars were extracted immediately before completing the osteotomy, whereas impacted third molars were removed after the osteotomy had been performed. Hardware reinforcement was performed in bimaxillary cases where concomitant molar extraction impeded placement of the retromolar bicortical screw of the hybrid technique. RESULTS: A total of 80 surgical sites were included (40 in each group). Concomitant extraction of the molar represented a mean increase in surgery time of 3.7 min (p < 0.001). No additional complications occurred in the test group (p = 0.476). The gain in bone density was preserved in both groups (p = 0.002), and the increase was of the same magnitude in both (p = 0.342), despite the fact that the immediate and final postoperative bone densities were significantly higher in the control group (p = 0.020). CONCLUSION: The results obtained support concomitant molar extraction with BSSO as a feasible option.

Prevalence of lingual sensory impairment following bilateral sagittal split osteotomy: a systematic review and meta-analysis.

PURPOSE: Our study aims to estimate the prevalence of lingual nerve injury following bilateral sagittal split osteotomy (BSSO). METHODS: Two reviewers independently conducted a systematic literature search in the Medline and Scopus databases. The pooled prevalence with 95% confidence intervals (CI) was estimated, and quality assessment, outlier analysis, and influential analysis were performed. RESULTS: In total, eleven eligible studies comprising a total of 1,882 participants were included in this meta-analysis. One study was identified as critically influential. The overall prevalence of lingual sensory impairment was estimated to be as high as 0.1% (95% CI 0.0%-0.6%) with moderate heterogeneity observed between studies. CONCLUSION: It is important for healthcare professionals to be aware of this issue, despite the relatively low rate of lingual nerve deficit after BSSO. Additional research will provide a more comprehensive understanding of the underlying factors contributing to lingual nerve injury, leading to improved preventive measures and treatment strategies. Furthermore, insights gained from future studies will enable healthcare professionals to inform patients about the potential complications and manage their expectations before undergoing BSSO.