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Abstract Aim The aim of this study was to evaluate the effect of local betamethasone injection into the pterygomandibular space on postoperative neurosensory deficits. Materials and methods A prospective controlled clinical study was conducted on 16 patients (6 male, 10 female; mean age, 24.95 ± 9.22 years) who underwent bilateral sagittal ramus osteotomy for mandibular discrepancies. One side of each patient’s mandible was randomly selected as the control side, and the opposite side as the experimental side. On the experimental side, a solution of betamethasone (6 mg/1 ml) was injected into the pterygomandibular space after the completion of wound closure. Neurosensory tests, including light touch, two-point discrimination, direction of movement, thermal sensitivity, and pin-prick discrimination, were performed. The follow-up period ranged between 6 and 12 months, according to the particular sensory test. The Fisher exact test was used to analyse the data. Results The light touch sensation was abnormal in 75% of the control side and 31% of the study side, with the difference being significant (p = 0.03). However, at 6 months, all the study cases regained touch sensation, compared to 69% of the control side. No significant difference in direction movement discrimination was seen; however, at 3 months, the study side showed significantly less direction sensation (19%) compared to the control side (56%) (p = 0.02). There was no significant difference in the two-point discrimination; however, at 3 months, the study side had a significantly less abnormal two-point sensation (13%) than the control side (56%) (p = 0.02). In addition, no significant difference was noted in thermal sensitivity or pin-prick sensation. Conclusion Betamethasone injection into the pterygomandibular space reduces neurosensory disturbances after bilateral sagittal split ramus osteotomies nd leads to faster recovery of sensations.

This study analyzed the biomechanical behavior under simulated conditions between a novel modification of the Low Z plasty (NM-Low Z) technique and the conventional Hunsuck–Epker (HE) technique on mandibular advancement surgery. The NM-Low Z technique was developed with the purpose of reducing post-operative complications by facilitating the operative method of lower jaw surgery. The models were investigated under physiological muscular and occlusal loads at 1, 2, 4, 6, and 8 weeks post-operation. Finite element analysis was used to analyze stress distribution, elastic strain, and model displacement. Maximum equivalent von Mises stresses were observed on the fixation system and bone. The elastic strain at the fracture site represented the optimal bone-healing capacity. The NM-Low Z model showed lower stress than the HE model at the 2-week post-operation stage and onwards. The elastic strains observed in both models were situated within the normal range for bone healing. The ranges of displacement for the NM-Low Z model were less than those in the HE model. Based on the data sets studied, the biomechanical study of the NM-Low Z technique can be favorably compared to the conventional HE technique. The NM-Low Z technique promotes post-operation skeletal stability by lowering stress on fixation and bone, with less displacement of the segment during bone-healing periods. [ABSTRACT FROM AUTHOR]

The 6- piece mandibular osteotomies was described in 1988 by Obwegeser H.L.; mobilizations interested 4 segments and the continuity between the left and right bodies was preserved. This piece of work aims to present a single surgical session for treating an adult with severe developmental deficiency of the mandible. The vertical height and projection of the patient middle third of the face and the SNA angle were within normal ranges contrasting to the 65° SNB. The 5-h procedures involved, in consequence, an incisor-canine subapical setback, an extended BSSO advancement and a double-stepped augmentation genioplasty. The lower third of the face was advanced by 25 mm. Combining mandibular osteotomies may safely save time and expenses.

Objectives: This retrospective study aimed to determine the angulation changes of the proximal segment following bilateral sagittal split osteotomy (BSSO) setback and its correlation with the amount of immediate postoperative surgical movement. The correlation between postoperative relapse of the distal and proximal segment at six months postoperatively was also evaluated. Materials and methods: The CBCT-generated lateral cephalometric images of 39 patients who underwent BSSO setback with or without Le Fort I osteotomy were evaluated preoperatively (T0), immediately postoperative (T1), and six months postoperatively (T2). Results: The mean surgical setback was 7.28 ± 4.45 mm at B point. The proximal segment's immediate postoperative mean posterior rotation was 2.13 ± 3.59 degrees. Six months after the operation, the mean distal segment relapse was 0.89 ± 3.03 mm at B point. The proximal segment relapse was 0.81 ± 1.63 degrees. A significant moderate correlation was found (P < 0.05) between the surgical movement and the immediate postoperative proximal segment rotation and between the surgical movement and the distal segment relapse. A significant correlation was found between the distal segment relapse and the average and left proximal segment relapse. There was no significant correlation between immediate postoperative proximal segment rotation and distal segment relapse. Conclusion: The immediate postoperative posterior rotation of the proximal segment had a negligible effect on mandibular relapse. The amount of surgical movement, on the other hand, was more related to distal segment relapse. The intraoperative proximal segment rotation should thus be minimized in cases with a significant surgical setback. [ABSTRACT FROM AUTHOR]

Inferior alveolar nerve (IAN) injury is most common in bilateral sagittal split osteotomy (BSSO) cases. The present standard is to always reposition the IAN from the proximal fragment to the distal fragment during surgery. This study aims to assess the severity and incidence of postoperative injury and the recovery of the inferior alveolar nerve in proximal fragment entrapment. Methods: — A total of 35 patients (70 BSSO osteotomies) with mandibular deformities requiring movements equal to or less than 6 mm were selected. Twenty out of 70 osteotomies had IAN on the proximal fragment (Group 1) while splitting. Group 2 included 20 osteotomies with IAN on the distal segment in the same patients. Therefore, 15 patients who had IAN on distal segments on both sides were excluded from this study. All the BSSO procedures were performed by the same surgeon. Postoperative recovery and follow-up were performed on the immediate 1st postoperative day and at 3-, 6- and 12-month intervals. The nociception (pin-prick discrimination) test and mechanoreceptive tactile skin test with cotton fibrils were performed by a third clinician who was blinded to the procedure to assess IAN sensation. Conclusion: There was no significant difference between the groups in the recovery of IAN sensation after 6 months and the 1-year period. Hence reposition of IAN from the proximal segment to the distal segment during BSSO surgery may not be mandatory if the required movement is within 6 mm. This avoids unnecessary manipulation of the IAN over the proximal fragment.

The orthognathic surgery plays an important role in achieving a pleasant-sounding dental, skeletal, and soft tissue which in turn helps an individual with jaw divergences to have function efficiency, aesthetic harmony, and structural balance. Pre-treatment profile photographs of the subjects were taken and morphed forward and backward, in 2 mm steps, until severely prognathic or retrognathic, respectively, to get class III and class II skeletal relation was acquired and the images were labeled from 1 to 5. The morphed profile photos were then camouflaged using Adobe Photoshop CS (v. 5.1) to generate silhouette images. The images were evaluated by three groups of assessors which includes orthodontists, oral surgeons, and laypersons. There was a statistically significant difference between oral surgeons, orthodontists, and laypersons in scoring class II (P < 0.001) for scoring adult females but no significance in rating adult males. There was a statistically significant difference between oral surgeons, orthodontists, and laypersons in scoring class III (P < 0.001) for scoring adult males and females. No difference was observed between scores when evaluated differently with the use of silhouettes or photos. [ABSTRACT FROM AUTHOR]

This study aimed to compare the condylar head displacement (CHD) after bilateral sagittal split ramus osteotomy (BSSO) between different degrees of mandibular advancement in skeletal class II patients and to evaluate whether the temporomandibular joint (TMJ) function would be affected. Fifty-nine patients (118 condyles) were included in this retrospective study and were divided into three groups based on the distance of mandibular advancement. The CHD in three directions, x (sagittal direction), y (coronal direction), and z (axial direction), was measured before operation (T0), immediately after operation (T1), and at least 6 months after operation (T2), and the TMJ function of patients was followed up and scored using the Helkimo index system. All the abovementioned data were statistically analyzed, and p < 0.05 was considered the statistical difference standard. During the BSSO surgery, the condyle was predominantly displaced in a lateral, posterior, and superior direction whenever in T1 and T2, even though the degree of CHD was different. Regarding the amount of CHD, the large advancement group was higher than the other two groups in T1 and T2 (p＜0.01). The Helkimo index scores of the three groups were evaluated, and there was no significant statistical difference between the Ai and Di index of the three groups. In our center, CHD occurred in lateral, posterior, and superior directions following mandibular advancement in skeletal class II patients, with a positive correlation between the CHD and the mandibular advancement; however, the TMJ function of the three groups did not show significant differences. [ABSTRACT FROM AUTHOR]

The orthognathic surgery plays an important role in achieving a pleasant-sounding dental, skeletal, and soft tissue which in turn helps an individual with jaw divergences to have function efficiency, aesthetic harmony, and structural balance. Pre-treatment profile photographs of the subjects were taken and morphed forward and backward, in 2 mm steps, until severely prognathic or retrognathic, respectively, to get class III and class II skeletal relation was acquired and the images were labeled from 1 to 5. The morphed profile photos were then camouflaged using Adobe Photoshop CS (v. 5.1) to generate silhouette images. The images were evaluated by three groups of assessors which includes orthodontists, oral surgeons, and laypersons. There was a statistically significant difference between oral surgeons, orthodontists, and laypersons in scoring class II (P < 0.001) for scoring adult females but no significance in rating adult males. There was a statistically significant difference between oral surgeons, orthodontists, and laypersons in scoring class III (P < 0.001) for scoring adult males and females. No difference was observed between scores when evaluated differently with the use of silhouettes or photos.

Inferior alveolar nerve (IAN) injury is most common in bilateral sagittal split osteotomy (BSSO) cases. The present standard is to always reposition the IAN from the proximal fragment to the distal fragment during surgery. This study aims to assess the severity and incidence of postoperative injury and the recovery of the inferior alveolar nerve in proximal fragment entrapment. — A total of 35 patients (70 BSSO osteotomies) with mandibular deformities requiring movements equal to or less than 6 mm were selected. Twenty out of 70 osteotomies had IAN on the proximal fragment (Group 1) while splitting. Group 2 included 20 osteotomies with IAN on the distal segment in the same patients. Therefore, 15 patients who had IAN on distal segments on both sides were excluded from this study. All the BSSO procedures were performed by the same surgeon. Postoperative recovery and follow-up were performed on the immediate 1st postoperative day and at 3-, 6- and 12-month intervals. The nociception (pin-prick discrimination) test and mechanoreceptive tactile skin test with cotton fibrils were performed by a third clinician who was blinded to the procedure to assess IAN sensation. There was no significant difference between the groups in the recovery of IAN sensation after 6 months and the 1-year period. Hence reposition of IAN from the proximal segment to the distal segment during BSSO surgery may not be mandatory if the required movement is within 6 mm. This avoids unnecessary manipulation of the IAN over the proximal fragment. [Display omitted] [ABSTRACT FROM AUTHOR]

Hemifacial microsomia (HFM), one of the most common congenital facial anomalies, was usually treated with the bilateral sagittal split osteotomy (BSSO) procedure to correct the asymmetric appearance and malocclusion of the mandible. However, the frequent post-operative relapse incidents would lead to the restoration of the mandibular segment to its preoperative position and failure of the BSSO procedure. In this study, a customized asymmetric fixed plate (CAF plate) was developed to resist relapse due to hemifacial microsomia occlusal forces and the different muscular traction forces on both sides of the mandible. For the actual HFM case in this study, the reconstructed mandibular segmental bone model was fixed using BSSO with a rectangular plate (the original CAF plate appearance) in the topology optimization analysis. With the topology optimization technique, the CAF plate was designed with a lightweight profile and excellent structural strength in consideration of the HFM asymmetrical muscle traction and occlusal force. Using biomechanical simulations, the von-Mises stress and CAF plate mandibular segment displacement and the miniplate were compared to evaluate which had superior relapse resistance. In the in-vitro biomechanical test, a fatigue force of 250,000 cycles and a constant muscle traction force were applied to the HFM mandibular model, which was fixed with the CAF plate fabricated using metal 3D printing (selective laser melting, SLM) to obtain the mandibular segment displacement as a relapse assessment. The topology optimization analysis showed that the CAF plate has the best characteristics, light weight and structural strength with 30% volume retention. The biomechanical analysis showed that the maximum von Mises stress of the mini-plate was 2.71 times higher than that of the CAF plate. The relapse displacement of the mandibular segment fixed with the mini-plate was 1.62 times higher than that fixed with the CAF plate. The CAF plate ability to resist relapse was confirmed by the biomechanical testing results so that only 0.29 mm of recurrence displacement was observed in the mandibular segment. The results indicated that the CAF plate structural strength and resistance to relapse was significantly better than that of the mini-plate. This study developed a customized asymmetric fixation plate for hemifacial microsomia, integrating topology optimization, metal 3D printing, and in vitro biomechanical testing to resist occlusal forces and differential muscle traction on both sides of the mandible to reduce relapse and improve fixation stability. [ABSTRACT FROM AUTHOR]

This study analyzed the biomechanical behavior under simulated conditions between a novel modification of the Low Z plasty (NM-Low Z) technique and the conventional Hunsuck–Epker (HE) technique on mandibular advancement surgery. The NM-Low Z technique was developed with the purpose of reducing post-operative complications by facilitating the operative method of lower jaw surgery. The models were investigated under physiological muscular and occlusal loads at 1, 2, 4, 6, and 8 weeks post-operation. Finite element analysis was used to analyze stress distribution, elastic strain, and model displacement. Maximum equivalent von Mises stresses were observed on the fixation system and bone. The elastic strain at the fracture site represented the optimal bone-healing capacity. The NM-Low Z model showed lower stress than the HE model at the 2-week post-operation stage and onwards. The elastic strains observed in both models were situated within the normal range for bone healing. The ranges of displacement for the NM-Low Z model were less than those in the HE model. Based on the data sets studied, the biomechanical study of the NM-Low Z technique can be favorably compared to the conventional HE technique. The NM-Low Z technique promotes post-operation skeletal stability by lowering stress on fixation and bone, with less displacement of the segment during bone-healing periods.

Introduction: The bilateral sagittal split ramus osteotomy (BSSRO) is the technique in vogue which is used for correction of a range of mandibular corpus deformity involving the dentoalveolar segment. The surgical technique has been subjected to a variety of modifications ever since its inception in the 1950s. One of the operative objectives which has been advocated sacrosanct has been the visual identification of lingula during the exposure of the medial aspect of the ramus. Materials and Method: BSSRO was successfully carried out in 45 cases operated over a period of eight years for correction of different kinds of skeletal mandibular deformity. The medial subperiosteal dissection did not involve a visual identification of the lingula. Conclusion: In our experience, the visual identification of the lingula is not essential to carry out a safe BSSRO procedure. [ABSTRACT FROM AUTHOR]

This study aims to analyse the relationship between the incidence of bad splits and the surgical tools adopteded to perform bilateral sagittal split ramus osteotomy (BSSRO).BSSROs performed by the same experienced surgeon period were reviewed, retrospectively. The patients were divided into three groups according to the surgical instrument used to perform the osteotomy: a Lindemann burr, reciprocating saw or piezosurgery. Among the 1120 BSSROs performed, 5 bad fractures were detected during the observation period: 3 among patients operated with the Lindemann burr (0.8%) and 2 among those operated with a reciprocating saw (0.5%). There was no significant correlation between the bad split rate and age and gender of the patients, the type of malocclusion or the type of instrument used to perform the osteotomy. Within the limitations of the study it seems that the the choice of the osteotomy tool for BSSRO does not influence the rate of bad fractures and, therefore, the selection of the osteotmy tool should be left to the discretion of the surgeon. [ABSTRACT FROM AUTHOR]

Abstract Background Virtual surgery planning (VSP) is believed to reduce inaccuracies in maxillary positioning compared to conventional surgery planning (CSP) due to the elimination of face-bow transfer and laboratory steps. However, there is still a lack of comparative studies for the accuracy of splint-based maxillary positioning in CSP versus VSP. Therefore, the objective of this retrospective, observational study was to compare if splints produced by VSP and CSP reach postoperative outcomes within clinically acceptable limits. Methods The planned and actual postoperative results of 52 patients (VSP: n = 26; CSP: n = 26) with a mean age of 24.4 ± 6.2 years were investigated by three-dimensional (3D) alignment with planning software. The conventional treatment plan was digitized, so that the evaluation of both methods was performed in the same manner using the same coordinate system. Inaccuracies were measured by sagittal, vertical and transversal deviations of the upper central incisors and the inclination of the maxillary occlusal plane between the planned and achieved maxillary positions. Results Both methods demonstrated significant differences between the planned and actual outcome. The highest inaccuracies were observed in vertical impaction and midline correction. No significant differences between CSP and VSP were observed in any dimension. Errors in vertical and sagittal dimension intensified each other. Conclusions In conclusion, splint-based surgeries reached similar results regardless of the applied planning method and splint production.

A novel modification of the Low Z plasty (NM-Low Z) technique for bilateral sagittal split osteotomy was recently proposed. The osteotomy line was modified more inferiorly than in the conventional Hunsuck–Epker (HE) approach. The NM-Low Z technique enhances the mandibular setback distance and degree of rotation in severe skeletal discrepancies. This study aimed to investigate the biomechanical behavior under simulated forces, and to compare the NM-Low Z and HE techniques on the mandible with Class III skeletal deformity at 1 week, 3 weeks, and 6 weeks post-operation. Physiological muscular and occlusal loads were simulated using the finite element (FE) method. Stresses on the miniplate, screws, and bone were observed and compared between the two models. The elastic strain at the fracture site was observed for the optimal bone-healing capacity. The NM-Low Z model exhibited a lower stress than the HE model at every stage post-operation. Both models demonstrated elastic strains within the normal range for bone healing. In summary, the biomechanical behavior of the NM-Low Z technique is comparable to that of the conventional EH technique. NM-Low Z could facilitate post-operation skeletal stability by reducing the stress on fixation materials during bone healing. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to evaluate the condylar vertical positional changes and stability after the bilateral sagittal split osteotomy (BSSO) setback procedure for class III malocclusions. Materials and methods: This was a retrospective study comprising lateral cephalograms of 11 patients with 8 males and 3 females who had undergone BSSO, without additional surgery. Manual superimposition was performed with the Frankfurt horizontal plane as a reference. Condylar vertical, linear, and angular positional changes, and chin position were considered. To compare pre- and postsurgical statistics paired t test was used. Significance was set at P-value

The goal of this study was to evaluate the incidence of postoperative wound infection and timing of mandibular third molar removal in bilateral sagittal split osteotomy (BSSO). This wis a prospective, single-blinded, randomized, split-mouth clinical trial. All patients were divided into two groups: Group I, where pre-operative removal of the third molars were done 6 months prior to BSSO and Group II, where intra-operative removal of contralateral third molars were done for the same patients during the osteotomy. The primary outcome variable studied was postoperative infection rate and the secondary outcome variable was bad split during BSSO. Among the seventy five patients (150 sites), one site in group II developed infection whereas none of the sites in group I developed infection (p = 1.000). No sites had bad split in both the groups. The results from the present study show that there is no difference between the presence or absence of mandibular third molars on post-operative wound infection following bilateral sagittal split osteotomy, and the authors hence suggest removing third molars during BSSO for patient comfort. [ABSTRACT FROM AUTHOR]

The aim of this systematic review was (i) to determine the role of muscular traction in the occurrence of skeletal relapse after advancement BSSO and (ii) to investigate the effect of advancement BSSO on the perimandibular muscles. This systematic review reports in accordance with the recommendations proposed by the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) statement. Electronic database searches were performed in the databases MEDLINE, Embase and Cochrane Library. Inclusion criteria were as follows: assessment of relapse after advancement BSSO; assessment of morphological and functional change of the muscles after advancement BSSO; and clinical studies on human subjects. Exclusion criteria were as follows: surgery other than advancement BSSO; studies in which muscle activity/traction was not investigated; and case reports with a sample of five cases or fewer, review articles, meta‐analyses, letters, congress abstracts or commentaries. Of the initial 1006 unique articles, 11 studies were finally included. In four studies, an intervention involving the musculature was performed with subsequent assessment of skeletal relapse. The changes in the morphological and functional properties of the muscles after BSSO were studied in seven studies. The findings of this review demonstrate that the perimandibular musculature plays a role in skeletal relapse after advancement BSSO and may serve as a target for preventive strategies to reduce this complication. However, further research is necessary to (i) develop a better understanding of the role of each muscle group, (ii) to develop new therapeutic strategies and (iii) to define criteria that allow identification of patients at risk. [ABSTRACT FROM AUTHOR]

Purpose: To compare the intraoperative utility of bur and saw and to examine the pattern of lingual split during bilateral sagittal split osteotomy of mandible. Material and methods: This study prospectively compares the intraoperative utility of bur and saw in bilateral sagittal split osteotomy as split-mouth model. Study includes 16 patients (representing 32 sagittal split osteotomies) divided into two groups. The procedure to be performed was explained to the patient, followed by written informed consent. The institutional ethical committee approved the clinical study and all subjects gave informed consent. Results: We found that the ease of handling of the bur was good compared to saw. The duration required for completion of osteotomy using bur was less compared to saw. Conclusions: The use of surgical drills and burs is still the gold standard in most developing nations and countries in transition like India. Depending upon the expertise of the surgeon, availability of precise dissecting instruments, one can go with either of the instrument for BSSO. [ABSTRACT FROM AUTHOR]

Historically, patients who received bilateral sagittal split osteotomies (BSSO) required an inpatient admission for at least one night. Since March 2015, the Oral and Maxillofacial Department at the Royal Gwent Hospital has performed bilateral sagittal split osteotomies (BSSO) as a day case procedure for their medically and socially fit patients. Our team's service evaluation by Davies et al (2018) for this procedure, demonstrated that this could be done both routinely and successfully, whilst conforming to national day case procedural standards. The aim of this satisfaction survey was to evaluate this procedure from a patient's perspective, to further consolidate our results from 2018. The forty-five patients who underwent day case BSSO (DCBSSO) between February 2015 and February 2020 were retrospectively identified and deemed eligible for inclusion. Participation involved completion of a 10-part questionnaire via telephone consultation. Patients were asked questions focussing on their experience of discharge timing, management of postoperative symptoms, and overall recovery at home. Twenty-four patients consented to partake in the survey (response rate of 73%). Twenty-three (96%) were extremely happy to be discharged the day of their surgery and felt that the timing of discharge was appropriate. Only 17% of patients experienced discomfort overnight and 96% of these stated they could manage their symptoms at home. From this survey, we can confirm that the majority of patients receiving DCBSSO at the Royal Gwent Hospital were happy to be discharged the day of their surgery and recover at home. [ABSTRACT FROM AUTHOR]

Background: Virtual surgery planning (VSP) is believed to reduce inaccuracies in maxillary positioning compared to conventional surgery planning (CSP) due to the elimination of face-bow transfer and laboratory steps. However, there is still a lack of comparative studies for the accuracy of splint-based maxillary positioning in CSP versus VSP. Therefore, the objective of this retrospective, observational study was to compare if splints produced by VSP and CSP reach postoperative outcomes within clinically acceptable limits. Methods: The planned and actual postoperative results of 52 patients (VSP: n = 26; CSP: n = 26) with a mean age of 24.4 ± 6.2 years were investigated by three-dimensional (3D) alignment with planning software. The conventional treatment plan was digitized, so that the evaluation of both methods was performed in the same manner using the same coordinate system. Inaccuracies were measured by sagittal, vertical and transversal deviations of the upper central incisors and the inclination of the maxillary occlusal plane between the planned and achieved maxillary positions. Results: Both methods demonstrated significant differences between the planned and actual outcome. The highest inaccuracies were observed in vertical impaction and midline correction. No significant differences between CSP and VSP were observed in any dimension. Errors in vertical and sagittal dimension intensified each other. Conclusions: In conclusion, splint-based surgeries reached similar results regardless of the applied planning method and splint production. [ABSTRACT FROM AUTHOR]

The aim of this prospective observational study was to investigate the parameter 'hidden blood loss' (HBL) in the context of orthognathic surgery, incorporating undetected bleeding volumes occurring intra- and postoperatively. Orthognathic bleeding volumes were recorded at three different time points. At the end of the operation the visible intraoperative blood loss (VBL) was measured. Additionally, the perioperative blood loss was calculated 24 h and 48 h postoperatively using the 'haemoglobin balance method'. Analysis of the HBL was based on the difference between the visible intraoperative blood loss (VBL) and calculated blood loss (CBL), determined 48 h after surgery. 82 patients (male 33, female 49) were included in this study, of whom 41 underwent bimaxillary surgery and of whom 41 underwent Bilateral Sagittal Split Osteotomy (BSSO). Statistically significant differences with reference to the absolute bleeding volumes were found when comparing the two treatment modalities. In terms of HBL, a bleeding volume of 287.2 ml (±265.9) in the bimaxillary group and 346.9 ml (±271.3) in the BSSO cohort was recorded. This accounted for 32.2% (bimaxillary surgery) and 62.6% (BSSO) of the CBL after 48 h (BIMAX vs. BSSO, p < 0.001). HBL is a valuable adjunct to record within the perioperative management of orthognathic surgery to further improve patient safety and postoperative outcomes. [ABSTRACT FROM AUTHOR]

This case report is one of the series study of this novel mandibular osteotomy technique. The purpose of this case report was to introduce mandibular osteotomy technique called the Novel Modification of Low Z Plasty (NM-Low Z) which modified from previous Prasan’s Low Z plasty. The technical approach were discussed and demonstrated in details. The case report was Skeletal class III mandibular prognathism which received lower jaw setback surgery with lengthening genioplasty by surgery first approach method. We had found benefits of this method which is not invading to airway dimension while performed a mandibular setback surgery. No any serious complication was reported after surgery. By only 3 months after surgery, the occlusion was ready for finishing orthodontic phase. Long term study is needed to conduct for skeletal stability. [ABSTRACT FROM AUTHOR]

Context: Orthognathic surgery brings about a harmonious relationship between jaws, resulting in improved facial aesthetics. It is key to analyze if satisfactory results can be attained by using virtual surgical planning for orthognathic procedures so as to recommend it for routine clinical practice., Aims: The aims of this study were to evaluate the various soft tissue changes that take place following orthognathic surgery using three-dimensional (3D) imaging and virtual surgical planning software and quantify the accuracy of virtual surgical planning software on patients undergoing orthognathic surgery., Settings and Design: This is an observational prospective study with a sample size of 12., Methods and Materials: In this prospective study, 12 patients undergoing orthognathic surgery were included following the inclusion and exclusion criteria. A usual pre-surgical work-up was done and a 3D replica of the facial skeleton was formulated using the software with the DICOM data acquired from the patient i.e., CT and scans of patient's dentition. Virtual surgical planning was done and splints were manufactured according to the desired newly achieved position. Patients were operated following the virtual surgical plan guided by the computer-aided design and computer-aided manufacturing (CAD-CAM) splints. Post-operative evaluation was done. As the study is more of a descriptive study to obtain detailed knowledge of a new procedure, only one group is being studied and hence there is no statistical testing included in this study., Results: The mean discrepancy noticed after superimposition of soft tissue points was 0.92 with a standard deviation of 0.3., Conclusions: 3D CT virtual surgical planning is a reliable tool to achieve predictable and reliable post-operative results in orthognathic surgical cases., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Institutional Review Board of SRM Dental College issued approval SRMDC/IRB/2020/MDS/No.405. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Srikanth et al.)

There are several treatment options to treat a class II dentofacial deformity with a pronounced chin. A total subapical osteotomy is one of these options. This type of osteotomy was refined to total subapical and ramus (TSAR) osteotomy. In this technical note, a detailed and schematic presentation of the TSAR osteotomy is presented step by step. The surgical approach to the TSAR osteotomy is divided into three parts. The first part consists of the horizontal osteotomy at the level of the ramus, the second part approaches the corticotomy to release and protect the mental nerve and the third part consists of connecting the horizontal ramus osteotomy and the local corticotomy around the mental nerve. In this third part, it is important that the inferior alveolar nerve (IAN) is actively sought and protected., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

The benefits of three-dimensional planning and guided surgery have been realised over the last few years in maxillofacial surgery. Reproducing the exact positioning of the cutting and drilling guides on the flat mandibular angles defined by the engineer is a challenge for the surgeon and for the reliability of guided bilateral sagittal split osteotomy. Reference screws positioned on the skeleton before the acquisition of medical computed tomographic data can provide a fixed landmark that can be used during surgery and by the engineer during the design phase. The objective of this proof of concept in vitro study is to calculate the accuracy obtained for guides positioned by inserting a reference screw. The precision obtained for 30 guides following the insertion of 30 reference screws on 15 mandibular models was analysed. The models were scanned using an optical scanner and compared to CAD-CAM projects. The mean (SD) absolute position (in)-inaccuracy is 0.1616 (0.1141) mm for the entire guide surface and 0.13143 (0.0835) mm for the rim surface. The results indicate that the use of reference screws is efficient, and so they can be used to position guides accurately during guided bilateral sagittal split osteotomy. [ABSTRACT FROM AUTHOR]

Incorrect registration of the condylar position in orthognathic surgery is supposed to cause postoperative relapse, condylar resorption and temporomandibular disorders. The aim of this prospective study was to evaluate the influence of general anaesthesia on centric relation (CR). Therefore, CR registered preoperatively in the awake patient and CR registered intraoperatively under general anaesthesia were recorded in 30 patients (14 men, 16 women) undergoing orthognathic surgery (skeletal class I: n = 3, II: n = 13, III: n = 14; symmetric: n = 20; asymmetric: n = 10). CR records were digitized and, through superimposition on the preoperative cone beam computed tomography of the patient's skull, the superior, anterior and posterior joint space and the volumetric congruence of 120 condyles were analysed. The linear measurements of joint spaces did not demonstrate any clinically relevant discrepancy between the CR measured in the awake and anaesthetized patient. In contrast, volumetric analysis revealed statistically significant differences between both states, with an intraoperative condylar sag predominantly in the posterior–inferior direction. The patient's skeletal class or symmetry had no significant influence on the intraoperative condylar displacement. Thus, the risk of fixing the condyle in an unphysiological position supports the idea of using intraoperative condylar positioning devices to achieve predictable and stable outcomes. [ABSTRACT FROM AUTHOR]

Objective: To analyse oral health related quality of life (OHRQoL) several years after orthognathic treatment in patients who had Class II malocclusion with retrognathic mandible.Material and methods: The initial study cohort comprised 151 patients with orthognathic treatment in 2007-2011. Of them, 77 patients (Group 1, mean age 41 years, range 19-71 years, 71% women) were clinically examined 6 years (range 4-8 years) after bilateral sagittal split osteotomy (BSSO). Group 2 included 24 former patients (mean 48 years, range 25-79 years, 50% women) who were willing to participate in a structured telephone interview. Group 3 consisted of 22 prospective patients (mean 35 years, range 18-56 years, 86% women) with a recent orthognathic treatment plan and awaiting treatment. QoL was assessed using two questionnaires, OHIP-14 and OQLQ.Results: Based on responses, patients who had received orthognathic treatment (Groups 1 and 2) had better QoL than those awaiting treatment (Group 3).Conclusion: Conventional orthognathic treatment, including mandibular advancement with BSSO, seems to have a positive long-term effect on patients' QoL. More long-term follow-up studies are needed to assess the real impact of treatment on patients' lives in the long run. [ABSTRACT FROM AUTHOR]

We have investigated the effect of photobiomodulation on the recovery of neurosensory function of the lip and chin after bilateral sagittal split osteotomy (BSSO). Laser irradiation was applied with a GaAs diode laser (continuous wave 980 nm wavelength, power 100 mW, and energy density 12 J/cm2). It was maintained within a 0.5 cm2 area in a total of 12 points for 60 seconds at each visit on each point. Unilateral extraoral contact photobiomodulation treatment was applied the day before operation and then on days 1, 3, 7, 14, 21, and 28 postoperatively. One side of the mandible was the intervention side and the other the control side. On the control side, the laser probe was turned off and placed on the chosen area. Neurosensory evaluations were made before and immediately after operation, and 30 days and 60 days postoperatively. Twenty-five patients were screened, and 18 who met the inclusion criteria were included in the study; 14 were women and the mean (SD) age was 23 (5) years. Analysis of the visual analogue scales for general sensibility, pain discrimination, directional discrimination, and 2-point discrimination showed a significant difference between the intervention and control sides after 30 days (p = 0.0011, 0.0034, 0.0023, and 0.0160, respectively). The difference was also significant after 60 days (p = 0.0001, 0.0002, 0.0003, and 0.0010, respectively). The thermal discrimination rate was significantly higher in the laser group than the control group 30 days after surgery (p = 0.002), but after 60 days the difference was not significant (p = 1.000). We found no side effects from the laser radiation during the two-month follow up. The results suggest that photobiomodulation accelerated the patients' improvement from neurosensory disturbance after BSSO. [ABSTRACT FROM AUTHOR]

Objectives: Postsurgical skeletal relapse is a concern for class II deformities corrected with counterclockwise rotation of the occlusal plane. Therefore, the aim of this study was to compare the skeletal stability between large and small counterclockwise rotational advancement of the mandible in patients with skeletal class II deformity. Materials and methods: This retrospective study included 50 adult patients with skeletal class II deformity corrected by Le Fort I setback and bilateral sagittal split osteotomy counterclockwise rotational advancement. Patients were divided into two groups, according to the amount of counterclockwise rotation: small rotation (n = 25) and large rotation (n = 25). Serial cone beam computed tomography scans were analyzed to identify skeletal and dental position from presurgery to at least 12 months postsurgery. Changes in the facial skeleton (maxilla and mandible) and teeth (central incisor and first molar) were determined for six skeletal and four dental landmarks by measures before treatment (T0) and 1 week postsurgery (T1), and from T1 to at least 12 months postsurgery (T2). Results: A relapse was found both after large and small rotational advancement of the mandible (pogonion: 1.0 (2.4) mm and 1.4 (3.0) mm, respectively). The result was statistically significant (both p < 0.05) and was with less than 1.5 mm clinically acceptable. There were no between-group differences in the postsurgical horizontal and vertical mandibular stability. Conclusions: The results suggest that counterclockwise rotational advancement of the mandible using bilateral sagittal split osteotomy is a clinically stable procedure. The amount of rotation does not affect the postsurgical stability of the mandible. Clinical relevance: The findings help clinicians better understand the surgical and postsurgical changes of the skeleton and teeth after counterclockwise rotational advancement of the mandible for class II deformity. [ABSTRACT FROM AUTHOR]