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(1) Background: The purpose of this study was to evaluate stability and complications following mandibular setback using intraoral vertical ramus osteotomy (IVRO) and provide an assessment of IMF (Inter-maxillary Fixation) compliance. (2) Methods: This is a retrospective cohort study. It included a total of 39 patients who underwent 78 IVRO for the treatment of mandibular prognathism between 2005 and 2021 at Sheba Medical Center. Radiographic and clinical examinations were performed preoperatively (T0), 3 days post-surgery (T1) and 8 months post-surgery (T2). Measurements of dental and skeletal stability, as well as neurosensory disturbances and TMJ dysfunctions, were statistically analyzed. (3) Results: The mean mandibular setback was 5.6 mm. A relapse of less than 2 mm was observed at T2. A short-term neurological disturbance was reported in 38.46% of the 39 patients, and 17.94% of them showed full recovery by T2. In 21 patients who underwent IVRO without genioplasty, only 14.28% reported long-term sensory disturbance. In addition, when a vertical osteotomy was performed, neurological damage was 174% higher as compared to oblique osteotomy. The IMF compliance rate for the 6 weeks postoperatively was 100%. (4) Conclusions: IVRO is still a relevant and valid technique for the treatment of mandibular prognathism that provides stable results with minimal complications rate. [ABSTRACT FROM AUTHOR]

The cheek line (face reading) is an aesthetic element of the facial profile. The purpose of our study was to investigate the changes in the cheek line after mandibular setback surgery. Forty patients (20 female and 20 male, mean (SD) age 22 (5) years) were diagnosed with mandibular prognathism and treated by intraoral vertical ramus osteotomy alone. Cephalograms were obtained before operation (T1), at least a year postoperatively (T2), and final surgical changes over a year (T2-T1). The cheek line and landmarks (soft and hard tissues) were compared using the paired t test. The hypothesis was that the cheek line did not change significantly after mandibular setback. At the time of the final follow-up (T2-T1), the mean (SD) horizontal setback of pogonion (Pog) was 12.3 (3.5) mm for women and 11.7 (4.3) mm for men. The ratios of soft:hard tissue, labrale inferius:incisor inferius, labiomental sulcus:point B, soft tissue Pog:Pog, and cheek point:Pog in women were 0.96, 0.98, 0.98, and 0.08, and in men 0.91, 1.01, 0.94, and 0.13, respectively. The nasolabial and cervicomental angles in women were significantly increased by 11.1° and 11.4°, respectively, and in men the nasolabial angle was significantly increased by 11.1° and the mentolabial angle reduced by 9.9°. The cheek line (T2-T1) was moved significantly forwards. The hypothesis was therefore rejected. In conclusion, the cheek line was advanced significantly after isolated mandibular setback. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the postoperative longitudinal skeletal changes and stability following intraoral vertical ramus osteotomies (IVRO) for orthognathic mandibular setback, and the possible risk factors that might affect the stability. A retrospective cohort study was conducted. Lateral cephalograms were analyzed for the predictor (magnitude of setback and adjunctive procedures) and outcome (stability of vertical and horizontal dimensions) variables at six time points. A total of 152 patients (mean age 24.2 years) were included in the study. Following IVRO, the mandible measured at B-point had moved a mean 0.50 mm posteriorly at 1 week after the removal of intermaxillary fixation (7 weeks postoperative); this was followed by progressive small anterior relapse. At 2 years postoperative, the mean relapse of the mandible after IVRO measured at B-point was 0.05 mm (standard deviation 1.14 mm), representing 0.7% of the mean surgical movement. Large setback (>8 mm) showed significantly higher relapse compared to small setback (<4 mm) at 2 years after surgery ( P = 0.021). Patients who underwent adjunctive mandibular surgeries other than IVRO showed no significant differences in relapse compared to those who underwent IVRO alone. In conclusion, IVRO for mandibular setback is a stable procedure in the long term, with small relapse of 0.05 mm after 2 years. [ABSTRACT FROM AUTHOR]

Objective: This study is aimed at assembling, through a systematic review and meta-analysis, scientific evidence related to the effects of mandibular setback (MdS) surgery and bimaxillary surgery for the correction of Class III malocclusion on the cross-sectional area (CSA) and volume of the upper airway as assessed using CT.Methods: An electronic search was conducted on Cochrane Library, EMBASE, PubMed, Scopus and Web of Science up to June 20, 2016. The inclusion criteria were prospective or retrospective studies, with the aim of comparing the impact on the upper airway space of orthognathic surgery for the treatment of the skeletal class III malocclusion. The methodological index for non-randomized studies (MINORS) was chosen as the evaluation instrument and Revman5.3 was used for the meta-analysis.Results: A total of 1213 studies were retrieved, of which only 18 met the eligibility criteria. The results of meta-analysis showed that the mean decrease in the upper airway volume after MdS surgery was 3.24 cm3 [95%CI (-5.25,-1.23), p = 0.85]; the mean decrease in minimum CSA after a combined surgery of maxillary advancement with mandibular setback (MdS + MxA) was 27.66 mm2 [95%CI (-52.81,-2.51), p = 0.51], but there was no significant decrease in upper airway volume (mean 0.86 cm3); comparison between MdS + MxA and isolated MdS showed significant differences in the CSA of the posterior nasal spine plane (PNS) and epiglottis plane (EP); statistically significant differences in nasopharynx volume (P < 0.0001) and upper airway total volume (P = 0.002) were observed, but no statistically meaningful variations existed in oropharynx volume (P = 0.08) and hypopharynx volume (P = 0.64).Conclusion: The results of this study suggest that bimaxillary surgery promotes less decrease on the upper airway than mandibular setback surgery alone for the correction of the skeletal class III malocclusion. [ABSTRACT FROM AUTHOR]

Objectives: This study examined the changes in temporomandibular joint dysfunction (TMD) symptoms and investigated the variations in the disc position, disc and condylar morphology following sagittal split ramus osteotomy (SSRO) with rigid fixation in patients with mandibular prognathism. Furthermore, the authors examined the correlation between mandibular setback and TMD symptoms.Methods: The study included 24 Japanese patients with jaw deformities who were treated using bilateral SSRO and Le Fort I osteotomy. The clinical and magnetic resonance imaging findings in the temporomandibular joint were evaluated preoperatively and at three and six months postoperatively.Results: The preoperative TMD symptoms were significantly associated with the prevalence of TMD symptoms at six months postoperatively. Anterior disc displacement improved in four joints with slight displacement and with no morphological change. There were no postoperative changes in condylar morphology. There was no significant correlation between mandibular setback and the postoperative TMD symptoms.Conclusion: Postoperative TMD symptoms may be influenced mainly by preoperative TMD symptoms rather than mandibular setback using SSRO with rigid fixation. Therefore, patients with TMD symptoms require physical examination and MRI for appropriate diagnosis preoperatively. [ABSTRACT FROM AUTHOR]

The purpose of this study was to elucidate the long-term skeletal and dental stability after combined orthodontic and orthognathic surgical treatment of mandibular prognathism with the intraoral vertical ramus osteotomy (IVRO) as the surgical technique followed by 6 weeks of intermaxillary fixation (IMF). Thirty-six patients were included in the study. Mean age at surgery was 21.6 years. Lateral cephalograms and study casts obtained before the start of treatment (T0), and 8 weeks (T1), 1 year (T2), and 12.5 years (T3) after the operation were evaluated. Mean mandibular setback measured at point B was 8.3 mm. Between T1 and T2, a mean anterior relapse of 12% of the setback was observed. Between T2 and T3, the anterior relapse persisted, but decreased to 7% of the setback measured at point B. Despite dental adjustments in both jaws, a statistically significant reduction in overjet was observed during both observation periods. However, the change of the mandible in an anterior direction was small and of minor clinical importance for most of the patients. In conclusion these results indicate that combined orthodontic and orthognathic surgical treatment of mandibular prognathism with the IVRO as the surgical procedure followed by 6 weeks of IMF provides predictable and good long-term clinical results. [ABSTRACT FROM AUTHOR]

Background: A bilateral sagittal split osteotomy for mandibular prognathism is a very popular and most versatile procedure performed on the mandibular body and ramus. The osteotomy splits the ramus and the posterior body of the mandible sagitally which allows either setback or abvancement. Method: This case report describes management of a skeletal Class III malocclusion with increased reverse overjet. Bilateral sagittal split osteotomy and mandibular setback was performed. Conclusion: The clinical outcome in the present case indicates that the management of skeletal class III malocclusion with a bilateral sagittal split osteotomy with mandibular setback gives promising results [ABSTRACT FROM AUTHOR]

Abstract: This study aimed to evaluate the correlation between the transverse displacement of the proximal segment after bilateral sagittal osteotomy for mandibular setback and the amount and design of the mandibular setback. Patients who underwent either bilateral sagittal split ramus osteotomy (BSSRO) alone or two-jaw surgery were selected, and cephalographic postero-anterior (PA) measurements were taken pre-operatively (T1), immediately post-operatively (T2), and at follow-up (T3). The inter-gonal (IG) and inter-ramal (IR) width increased immediately after surgery, but decreased to the initial value during follow-up (P =0.002; IR, P =0.046). Only the immediate IG changes after surgery correlated with the amount of mandibular setback (P =0.009). The IG changes were significant in the symmetric group, but not in the asymmetric group. There was no difference in the IG and IR changes between the symmetric group and the asymmetric group. The immediate IG change in two-jaw patients with symmetric setback showed correlation with the setback amount. The gonial width of the deviated group showed more significant changes than that of the non-deviated group. There was no difference in the unilateral gonial width between the deviated and the non-deviated group, but the difference was significant for the unilateral ramal angle between the two groups. These correlations will be helpful in predicting post-surgical results for patients. [Copyright &y& Elsevier]

Background/Purpose: This study aimed at comparing the transverse and sagittal angulations of proximal segment after sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO), and examining their influences on the stability of distal segment. Methods: Patients who received SSRO (n = 21) or IVRO (n = 11) for mandibular setback were included. Lateral and posteroanterior cephalograms taken within 1 month before surgery (T1), within 1 week after surgery (T2), and at least 6 months after surgery (T3) were analyzed. The angulation of each proximal segment relative to the upper orbital margin line was measured on posteroanterior cephalogram and the sum of both angles (total ramus angle, TRA) was obtained. On lateral radiograph, ramus inclination angle (RIA) relative to a horizontal reference line 7° to the sella–nasion was assessed and B-point position was measured. Results: From T1 to T2, more increases in TRA and RIA were noted after IVRO than after SSRO. From T2 to T3, TRA and RIA significantly decreased in IVRO group but remained relatively stable in SSRO group. ΔTRAT1–T2 positively related to upward rotation of distal segment for SSRO and downward rotation for IVRO from T2 to T3. For SSRO only, ΔRIAT1–T2 significantly related to forward movement of distal segment during remodeling. Conclusion: TRA and RIA increase significantly after IVRO and then regress, whereas they increase mildly after SSRO and remain stable. Increase in TRA significantly relates to distal segment rotation during remodeling for both surgeries, but increase in RIA relates to forward relapse of the distal segment only for SSRO. The reasons underlying the correlations are not certain and deserve future investigations. [ABSTRACT FROM AUTHOR]

Two-jaw surgery has been performed for the treatment of severe skeletal open bite cases to obtain stability of occlusion after treatment. If molar intrusion with titanium screws could be performed instead of surgical superior repositioning of the maxilla, the incidence of surgical invasion would be reduced. However, there have been few reports of such a therapy. This case report describes treatment for skeletal Class III and open bite with bilateral sagittal split osteotomy and intrusion of the molars using titanium screws. The patient had a concave profile, a long lower facial height, Class III malocclusion, and excessive anterior open bite following mandibular protrusion and a high mandibular plane angle. The mandible autorotated closed 3.5° following intrusion of the upper and lower molars using titanium screws during the presurgical orthodontic treatment phase. After the autorotation of the mandible, a mandibular setback with a bilateral sagittal split osteotomy was performed. The posttreatment records showed a good facial profile and occlusion. The mandible was stable 1 year after surgery. These results demonstrate that surgical orthodontic treatment combined with bilateral sagittal split osteotomy and intrusion of the molars using titanium screws can reduce the need for surgical invasion by avoidance of maxillary surgery and was effective for correcting the facial profile and occlusion in a skeletal Class III and open bite patient. [ABSTRACT FROM AUTHOR]

Objective: To assess changes in hyoid, tongue, pharyngeal airway, and head posture in patients who had mandibular setback surgery by intraoral vertical ramus osteotomy (IVRO) and to investigate the influence of LeFort I osteotomy. Materials and Methods: Sixty patients with skeletal Class Ill malocclusion were evaluated. All patients had mandibular setback surgery via IVRO, and 45 patients had additional maxillary impaction surgery via LeFort I osteotomy. Lateral cephalograms were taken before, immediately after, approximately 1 month after, and at least 1 year after surgery. Parameters indicating the hyoid, tongue, pharyngeal airway, and head posture were evaluated. Results: The hyoid significantly moved inferoposteriorly immediately after surgery and relapsed superoanteriorly during observation periods. The tongue significantly moved posteriorly during all periods. The final position of the hyoid and tongue was significantly posterior, and the final pharyngeal airway was significantly narrower compared with its presurgical position. Significant cervical hyperflection occurred during observation periods and was strongly correlated with anterior movement of the hyoid. The hyoid and tongue showed similar positions regardless of the presence of different genders or LeFort I osteotomy after the long-term observation period. Conclusions: The hyoid and tongue moved posteriorly after mandibular setback surgery via IVRO, and there was a tendency to relapse back to its original position. However, the final pharyngeal airway width remained narrower after the long-term observation period. Based on our results, careful monitoring of the airway may be needed after mandibular setback surgery via IVRO. [ABSTRACT FROM AUTHOR]

Summary: Aim: The purpose of this study was to examine morphological changes of the mandibular region using frontal cephalograms following bilateral sagittal split osteotomy (BSSO) for mandibular setback. Furthermore, we compared the stability between screw and plate fixation. Methods: Pre and postoperative frontal cephalograms were taken of 26 patients. Parameters, Angle “A” which is formed by constructed lines along the mandibular ramus, and mandibular width at the angle were calculated. The subjects were analyzed according to the types of bony fixation, whether by screws or plates. Results: Angle “A” and mandibular angular width of total numbers did not widely change at early period following operation. Late postoperatively, mandibular width of total numbers decreased in conjunction with increasing Angle “A”. When comparing the parameters between screw and plate groups, the plate group showed a decrease of Angle “A” as an early change. Late postoperatively, the plate group showed an increase of Angle “A” and a decrease of mandibular width, while the screw group had smaller changes. Conclusion: We demonstrate postoperative inclination of mandibular lower ramus towards the facial midline. We suggest that the types of rigid fixation have an influence on frontal skeletal morphology, namely that screw fixation has higher stability. [Copyright &y& Elsevier]

Abstract: Cephalometric studies show significant gender differences in the size of the pharyngeal airway space. This study aimed to investigate and compare morphologic changes after mandibular setback or two-jaws surgery on the pharyngeal airway in men and women using computed tomography (CT). The sample included 34 women and 13 men diagnosed with Class III skeletal deformities, who had been treated by mandibular setback or bimaxillary surgery (maxillary advancement and mandibular setback). Anteroposterior, lateral and cross-sectional area dimensions of the airway, at the level of soft palate and base of tongue, were measured pre- and postoperatively on CT images. In the mandibular setback group, the anteroposterior and cross-sectional area of the pharyngeal airway at the level of the soft palate and base of tongue were significantly reduced for men or women (P <.05). In the two-jaws surgery group, only midsagittal anteroposterior dimensions at the same levels were significantly decreased for men or women (P <.05). The difference between any values measured between men and women who received bilateral sagittal split ramus osteotomy setback surgery or two-jaws surgery for the treatment of class III anteroposterior discrepancy were not statistically significant (P >.05). This study suggests that oropharyngeal airway measurements, important for airway patency, do not demonstrate sex dimorphism. [Copyright &y& Elsevier]

Short- and long-term skeletal changes after mandibular setback were analyzed using bilateral sagittal split ramus osteotomy. Twelve patients who had undergone mandibular setback surgery between 1986 and 1990 were available for long-term cephalography on average 12 years after primary surgery. The mean amount of surgical setback had been 6.4?mm. After the first postoperative year, there was skeletal relapse of 1?mm at the B-point and pogonion (Pg), amounting to 14% of the initial skeletal setback. In contrast to condylar displacement and proximal segment rotation, osteotomy slippage was associated with positional changes at the B-point and Pg. From 1 to 12 years postoperatively, the B-point and Pg remained stable. Mandibular ramus and corpus length decreased 2.1?mm and 1.3?mm, respectively, indicating remodeling at the osteotomy sites and probably condylar resorption. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of present study was to review the literature regarding the postoperative skeletal stability in the treatment of mandibular prognathism after isolated sagittal split ramus osteotomy (SSRO) or intraoral vertical ramus osteotomy (IVRO). Materials and Methods: The articles were selected from 1980 to 2020 in the English published databases (PubMed, Web of Science and Cochrane Library). The articles meeting the searching strategy were evaluated based on the eligibility criteria, especially at least 30 patients. Results: Based on the eligibility criteria, 9 articles (5 in SSRO and 4 in IVRO) were examined. The amounts of mandibular setback (B point, Pog, and Me) were ranged from 5.53–9.07 mm in SSRO and 6.7–12.4 mm in IVRO, respectively. In 1-year follow-up, SSRO showed the relapse (anterior displacement: 0.2 to 2.26 mm) By contrast, IVRO revealed the posterior drift (posterior displacement: 0.1 to 1.2 mm). In 2-year follow-up, both of SSRO and IVRO presented the relapse with a range from 0.9 to 1.63 mm and 1 to 1.3 mm respectively. Conclusion: In 1-year follow-up, SSRO presented the relapse (anterior displacement) and IVRO posterior drift (posterior displacement). In 2-year follow-up, both of SSRO and IVRO showed the similar relapse distances. [ABSTRACT FROM AUTHOR]

Abstract: The aims of this study were to analyze possible contributing factors to intraoperative clockwise rotation (CWR) of the proximal segment (PS), which is known to be a primary factor for relapse after mandibular setback with sagittal split ramus osteotomy (SSRO) and to evaluate the correlation between the CWR of the PS and relapse tendency. The sample was comprised of 47 patients who underwent SSRO for mandibular setback. Lateral cephalograms were analyzed. The vertical difference between the inferior borders of the PS and the distal segment at the vertical osteotomy line for SSRO after setback of the distal segment (vertical bony step, VBS) was the most predictable factor for CWR of the PS (p < 0.001), and it correlated significantly with the gonial angle, the surgical change in SNB, and the downward movement of the maxilla (p < 0.05). Patients with large CWR of the PS showed a greater tendency in horizontal relapse than patients with small CWR of the PS (p < 0.05). Such relapse patterns could be prevented with adequate surgical planning designed to reduce the VBS, such as maxillary posterior impaction or the intentional guidance of the PS to maintain the original position of the PS without CWR. [Copyright &y& Elsevier]