Bilateral Sagittal Split Osteotomy Research Articles

Assessment of mandibular bony healing, mandibular condyle and angulus after orthognathic surgery using fractal dimension method.

This study aims to compare the trabeculation changes in the bone structure observed at the mandibular osteotomy line and the mandibular condyle in patients after single and double-jaw orthognathic surgery. The study included 38 patients (23 female, 15 male) who underwent mandibular surgery with bilateral sagittal split ramus osteotomy technique. The patients were divided into two groups according to their surgical operation: single-jaw (bilateral sagittal split ramus osteotomy) or double-jaw (Le Fort I osteotomy and bilateral sagittal split ramus osteotomy) surgery. Trabecular changes seen in mandibular osteotomy lines, mandibular condyle and mandibular angulus were evaluated on panoramic radiographs of patients (preoperative, postoperative 2nd day, postoperative 3rd month and 12th month) using fractal analysis method. Fractal dimension analysis was calculated by box counting method. No statistically significant difference was found between the fractal analysis values in the mandibular condyle and angulus region preoperatively, postoperative 2nd day, postoperative 3rd month and postoperative 12th month in the single jaw group. There was no statistically significant difference between the fractal analysis values in the mandibular condyle and angulus region preoperatively, postoperative 2nd day, postoperative 3rd month and postoperative 12th month in the double jaw group. A significant difference was found in fractal analysis values in osteotomy lines in both groups. The lowest value was found on the 2nd postoperative day and reached the preoperative values in the 3rd and 12th months postoperatively. Fractal analysis values didn't show significant difference between the single, double-jaw groups in all periods. This result suggests that the fractal analysis method can be used to evaluate trabeculation in the bone healing process of the osteotomy lines and indirectly affected areas in the postoperative period after orthognathic surgery.

Cephalometric evaluation of skeletal stability and pharyngeal airway changes after mandibular setback surgery: Bioabsorbable versus titanium plate and screw fixation.

This study compared sequential changes in skeletal stability and the pharyngeal airway following mandibular setback surgery involving fixation with either a titanium or a bioabsorbable plate and screws. Twenty-eight patients with mandibular prognathism undergoing bilateral sagittal split osteotomy by titanium or bioabsorbable fixation were randomly selected in this study. Lateral cephalometric analysis was conducted preoperatively and at 1 week, 3-6 months, and 1 year postoperatively. Mandibular stability was assessed by examining horizontal (BX), vertical (BY), and angular measurements including the sella-nasion to point B angle and the mandibular plane angle (MPA). Pharyngeal airway changes were evaluated by analyzing the nasopharynx, uvula-pharynx, tongue-pharynx, and epiglottis-pharynx (EOP) distances. Mandibular and pharyngeal airway changes were examined sequentially. To evaluate postoperative changes within groups, the Wilcoxon signed-rank test was employed, while the Mann-Whitney U test was used for between-group comparisons. Immediate postoperative changes in the airway were correlated to surgical movements using the Spearman rank test. Significant changes in the MPA were observed in both the titanium and bioabsorbable groups at 3-6 months post-surgery, with significance persisting in the bioabsorbable group at 1 year postoperatively (2.29°±2.28°; P<0.05). The bioabsorbable group also exhibited significant EOP changes (-1.21±1.54 mm; P<0.05) at 3-6 months, which gradually returned to non-significant levels by 1 year postoperatively. Osteofixation using bioabsorbable plates and screws is comparable to that achieved with titanium in long-term skeletal stability and maintaining pharyngeal airway dimensions. However, a tendency for relapse exists, especially regarding the MPA.

Long-Term Follow-Up of Orthognathic Surgery in 19 Patients with Juvenile Idiopathic Arthritis.

Dentofacial deformity following juvenile idiopathic arthritis with temporomandibular joint involvement is associated with functional, aesthetic, and psychosocial impairment. Surgical treatment may involve combinations of orthognathic surgery. The aims of this retrospective study were to assess orofacial symptoms, functional and aesthetic status, and stability after orthognathic surgery. Nineteen patients with juvenile idiopathic arthritis of the temporomandibular joint (TMJ) and dentofacial deformities were included. All patients were treated with combinations of bilateral sagittal split osteotomy, Le Fort I and/or genioplasty, between September 10, 2007 and October 17, 2017. Analysis of patient symptoms and clinical registrations, and frontal/lateral cephalograms was performed pre- and postoperative and long-term (mean: 3.8 and 2.6 years, respectively). Patients experienced no changes in orofacial symptoms or TMJ function, and stable normalisation of horizontal and vertical incisal relations at long-term (horizontal overbite; vertical overbite: P < 0.05). Mandibular lengthening was achieved postoperatively (from mean 79.7 to 87.2 mm; P = 0.004) and was stable. Sella-nasion to A point (SNA) and sella-nasion to B point (SNB) angles increased postoperatively (SNA, mean 79.9° to 82.8°; P = 0.022 and SNB, mean 73.9° to 77.8°; P = 0.003), however, largely reverted to preoperative status at long-term. Orthognathic surgery normalized incisal relations while providing stable mandibular lengthening without long-term deterioration of temporomandibular joint function or orofacial symptoms. No long-term effect on jaw advancements was observed.

Bilateral Sagittal Split Osteotomy with Mandibular Setback - A Case Report

Bilateral Sagittal Split Osteotomy with Mandibular Setback - A Case Report

Skeletal stability after mandible bilateral sagittal split osteotomy – comparison of patient-specific implant and mini-plate fixation: A retrospective study

The aim of the study was to compare the stability of the virtual surgical planning (VSP) and computer-aided design accompanied by patient-specific implants (PSIs) and conventional mini-plates in mandible advancement with bilateral sagittal split osteotomy (BSSO).This retrospective study evaluates the clinical and cephalometric records of 53 patients (12 male, 41 female) treated with BSSO in Helsinki University Hospital. Subjects were divided into two groups: VSP–PSI (21 patients: 4 male and 17 female; mean age 38 years, range 25–53 years); and conventional wafer-based repositioning with mini-plate fixation (32 patients: 8 male and 24 female; mean age 39 years, range 21–56 years). The effect of the amount and direction of the advancement on the stability was also analysed individually. The standardized lateral cephalometric radiographs in three time points were analysed to compare the groups.After surgery (T2), there were no differences between groups in cephalometric variables. During follow-up (T2–T3), the cephalometric variables in both Groups A and B were stable, so there was no difference in stability between the VSP–PSI and the conventional mini-plate groups. During follow-up, the mandibles rotated clockwise or counterclockwise, relapsed towards their original direction, and the changes were statistically significant (jaw relationship; p = 0.018, soft tissue profile; p = 0.025); when the advancement of mandible was >6 mm, the increase in gonial angle compared to mandibles advanced ≤6 mm was statistically significant (p = 0.03).VSP–PSI and conventional mini-plate fixation can be considered equally stable. Large advancements with counterclockwise rotation regardless of fixation method are more susceptible to relapse. VSP-PSI alone cannot solve the relapse-related concerns in mandible osteotomy.

P125 Patient reported outcome measures (PROMs) following bilateral sagittal split osteotomy with osseous genioplasty

P125 Patient reported outcome measures (PROMs) following bilateral sagittal split osteotomy with osseous genioplasty

Condylar volume and positional changes following a bilateral sagittal split ramus osteotomy in skeletal class II and III malocclusions

BackgroundMandibular condyle remodeling and displacement are post-orthognathic surgery concerns that can potentially lead to occlusal issues after bilateral sagittal split ramus osteotomy. This retrospective study examined the relationship between condylar volume changes and position alterations after surgery in patients with skeletal class II and III malocclusions using cone-beam CT.MethodsThe study included 16 patients (6 with Class II malocclusion, 10 with Class III malocclusion) who underwent bilateral sagittal split ramus osteotomy at Chonnam National University Hospital. Cone-beam CT data were collected at three specific time points: before surgery, immediately after surgery, and approximately 6 months post-surgery. Mandibular movement was measured using InVivoDental 5.4.6. ITK-SNAP 3.8.0 was used to assessed condylar volume changes post-surgery. Condyle positions were evaluated in four parts with RadiAnt DICOM Viewer 4.6.9. Statistical analyses were performed using the SPSS version 23.ResultsConsidering both Class II and III malocclusion, a 2.91% volume reduction was noted immediately and at 6 months after surgery. Both Class II and III cases demonstrated a decrease in superior joint space by -0.59 mm and medial joint space by -1.09 mm. No significant correlation was found between this process and condylar volume change.ConclusionsThe mandibular condyle volume decreased, and superior-medial movement of the condyle was detected in patients with Class II and III malocclusion immediately and at 6 months after surgery with no volume-position correlation.

Does Anesthesiologist Experience Influence Early Postoperative Outcomes Following Orthognathic Surgery?

Anesthesia provider experience impacts nausea and vomiting in other surgical specialties but its influence within orthognathic surgery remains unclear. The study purpose was to evaluate whether anesthesiologist experience with orthognathic surgery impacts postoperative outcomes, including nausea, emesis, narcotic use, and perioperative adverse events, for patients undergoing orthognathic surgery. This is a retrospective cohort study of subjects aged 12 to 35years old who underwent orthognathic surgery, including Le Fort 1 osteotomy±bilateral sagittal split osteotomy, at Boston Children's Hospital from August 2018 to January 2022. Subjects were excluded if they had incomplete medical records, a syndromic diagnosis, or a hospital stay of greater than 2days. The predictor variable was attending anesthesia provider experience with orthognathic surgery. Providers were classified as experienced or inexperienced, with experienced providers defined as having anesthetized ≥10 orthognathic operations during the study period. The primary outcome variable was postoperative nausea. Secondary outcome variables were emesis, narcotic use in the hospital, and perioperative adverse events within 30days of their operation. Study covariates included age, sex, race, comorbidities (body mass index, history of psychiatric illness, cleft lip and/or palate, chronic pain, postoperative nausea/vomiting, gastrointestinal conditions), enhanced recovery after surgery protocol enrollment, and intraoperative factors (operation performed, anesthesia/procedure times, estimated blood loss, intravenous fluid and narcotic administration, and anesthesiologist's years in practice). χ2 and unpaired t-tests were used to compare primary predictor and covariates against outcome variables. A P-value <.05 was considered significant. There were 118 subjects included in the study after 4 were excluded (51.7% female, mean age 19.1±3.30years). There were 71 operations performed by 5 experienced anesthesiologists (mean cases/provider 15.4±5.95) and 47 cases by 22 different inexperienced providers (mean cases/provider 1.91±1.16). The nausea rate was 52.1% for experienced providers and 53.2% for inexperienced providers (P=.909). There were no statistically significant associations between anesthesiologist experience and any outcome variable (P>.341). Anesthesia providers' experience with orthognathic surgery did not significantly influence postoperative nausea, emesis, narcotic use, or perioperative adverse events.

Advantages of a High-Powered Ultrasonic Vibration Cutting Device for Orthognathic Surgeries.

This study aimed to evaluate the advantages of using a high-powered ultrasonic vibration cutting device (HP-UVCD) in orthognathic surgeries. We analyzed 22 consecutive patients who underwent Le FortⅠosteotomy and bilateral sagittal split osteotomies for cleft lip and palate. We used conventional power instruments, such as reciprocating saws and rotating burrs in the first 10 patients, and an HP-UVCD in the remaining 12 patients. Surgical time, intraoperative blood loss, and postoperative inferior alveolar nerve affection were retrospectively investigated. The surgical time in the ultrasonic group (223±12.217min) was significantly shorter than that in the conventional group (278±11.153min, P =0.008). The amount of intraoperative blood loss in the ultrasonic group was an average of 230±45.154g, and that in the conventional group was an average of 343±49.463g. Although the blood loss in the ultrasonic group was reduced compared with that in the conventional group, this difference was not statistically significant ( P =0.118). All patients in both groups recovered normal sensation by 6 months postoperatively. Our findings suggest that the HP-UVCD can be used in place of a reciprocating saw or rotating burrs in orthognathic surgeries, resulting in reduced surgical time and minimal blood loss. The use of an ultrasonic bone-cutting device may allow for a safer and less invasive orthognathic surgery.

Accuracy of computer-assisted design and manufactured three-dimensional device for condylar positioning in mandibular bilateral sagittal split osteotomy (clinical trial)

Aligning dental arches in orthognathic treatment after undergoing LeFort I osteotomy or bilateral sagittal split osteotomy (BSSO) relies on occlusal splints, which do not provide precise control over the condylar head. To clinically and radiographically assess the accuracy of computer-assisted design and manufactured (CAD/CAM) surgical guide for condylar positioning in a BSSO. The study recruited 8 patients with a non-syndromic dentofacial deformity who underwent a BSSO. Surgery was planned according to CAD/CAM technology. After osteotomy, a pre-operative guide was used, followed by a repositioning guide. Computed tomography scans were conducted on all patients 1 week pre-operatively, immediately, and 3 months postoperatively. The data are presented as median values with the 25th and 75th percentiles. Eight patients (37.50% females and 62.50% males) between the ages of 19 and 24 underwent BSSOs. The surgical procedure successfully corrected their skeletal deformities. The absolute change between immediate postoperative and pre-operative condylar angle was 0.15 (0.00-0.3). The absolute change between 3 months postoperative and pre-operative condylar angle was 0.20 (0.00-0.30). The stability of the condylar head in position is well assessed by 3-dimensional condylar positioning devices designed and manufactured by CAD/CAM technology in the mandibular BSSO.

Does osteotomizing the lower border of the mandible affect the lingual split pattern in a sagittal split ramus osteotomy?

AimThe purpose of this study was to evaluate the effect of adding a fourth osteotomy at the lower border of the mandible on the lingual cortical fracture pattern in bilateral sagittal split ramus osteotomies.Patients and methodsThe sample of the study consisted of 20 patients (12 male and 8 female, with a mean age of 26.79 ± 7.12 years) with mandibular deformities who needed bilateral sagittal split ramus osteotomy. One side underwent a traditional sagittal split ramus osteotomy, and the procedure was modified on the other side by adding a 1 cm horizontal osteotomy at the lower border of the mandible, just distal to the caudal end of the vertical buccal osteotomy cut. A 3D CBCT was used to identify the split pattern.ResultsIn the total sample, 40% of the lingual splits ran vertically toward the lower border of the mandible (LSS1), 20% of the splits passed horizontally to the posterior border of the mandible (LSS2), 32.5% of the splits took place along the inferior alveolar canal (LSS3), and 7.5% of the splits were unfavourable fractures (LSS4). On the inferior border osteotomy sides, the distribution of LSS1, LSS2, LSS3, and LSS4 was 10 (25%), 6 (15%), 4 (10%), and 0 (00), respectively. Their distribution on the sides without inferior border osteotomy was 6 (15%), 8 (20%), 13 (32.5%), and 3 (7.5%), respectively. Statistical analysis revealed a significant difference between the two groups (p < 0.05).ConclusionInferior border osteotomy tends to direct the lingual split fracture line toward the lower and posterior borders of the mandible and minimizes bad splits; however, further studies are needed to confirm our findings.

Does Articular Disc Position Change Following Mandibular Setback Surgery?

BackgroundMaintaining condyle position following bilateral sagittal split ramus osteotomy (BSSO) is crucial to minimizing post-operative relapse. However, the impact of BSSO on the articular disc position remains inconclusive. PurposeThis study aimed to investigate the changes in articular disc position following setback BSSO surgery.Study design, setting, and sampling: In this prospective cohort study, subjects with mandibular prognathism requiring setback BSSO were enrolled between August 2021 and June 2022 at the Oral and Maxillofacial Surgery Clinic, Faculty of Dentistry, Chiang Mai University, Thailand. Patients with surgical complications, loss of follow-up, or significant artifacts in their MR images were excluded.' Predictor/exposure/independent variablesThe predictor variable was time and articular disc position was assessed at 3 time points, preoperatively (T0), three months post-surgery (T1), and six months post-surgery (T2). Main outcomeThe primary and secondary outcome variables were the changes in articular disc position between T0-T2 and T0-T1, respectively. Articular disc position was coded as normal, anterior disc displacement with reduction (ADDwR), anterior disc displacement without reduction (ADDwoR), and anterior disc displacement without reduction and degenerative joint disease (ADDwoR+DJD). CovariatesCovariate variables collected included age (years), sex (male or female), asymmetry (present or absent), surgical procedure (single jaw (BSSO) or bimaxillary surgery), and setback distance (millimeters). AnalysesFriedman’s test with 80% power and a significance level of 0.05 was employed. Pairwise comparisons were performed using the Dunn-Bonferroni post hoc test to identify statistically significant differences. ResultsThe study included 16 subjects, six females and ten males, with a total of 32 TMJs. Subjects had a mean age of 23.75 (4.57) years. The proportion of TMJs with normal disc position postoperatively increased from 3 (9.4%) to 19 (59.4%). Statistically significant differences were found in the changes in disc position over time (P < .001). ConclusionsFollowing setback BSSO, the articular discs underwent changes, with a majority of ADDwR cases transitioning to a normal position. Cases with ADDwoR also demonstrated disc reduction capability after surgery. The combined orthodontic treatment and setback BSSO appear to have an effect on articular disc position in skeleton class III patients.

The effect of different hybrid rigid internal fixation techniques on the postoperative stability following a mandibular advancement using a bilateral sagittal split ramus osteotomy: A retrospective three-dimensional comparative study

ObjectiveTo three-dimensionally evaluate post-operative mandibular stability following bilateral sagittal split ramus osteotomies between hybrid and non-hybrid rigid internal fixation techniques. Materials and MethodSeventy adults with skeletal class II deformity who underwent bilateral split sagittal osteotomy with mandibular advancement were included. Patients were divided into four groups based on their fixation techniques: hybrid technique (HT) groups I, II, and IV received a 4-hole 2 mm miniplate with either a bicortical screw (BS), additional 2 mm 4-hole miniplate, or two-hole miniplate, while non-HT group III received a 4-hole 2 mm miniplate with four mini-screws (MS). Measurements were taken pre-operatively (T0), immediately postoperatively (T1), and ≥1 year after surgery (T2) using 3D Slicer software. ResultsAge, sex, and follow-up period did not correlate significantly with postoperative relapse or stability. Significant differences were observed in the advancement on the right side between groups II, III, and IV and on the left side between groups I, III, and IV. However, the type of surgical intervention showed no significant effect on postoperative relapse and stability. All groups of fixations showed satisfactory stability with irrelevant relapse (< 2 mm or 2°). ConclusionThe study demonstrated satisfactory and comparable stability among different fixation groups on patients undergoing mandibular advancement following bilateral split sagittal osteotomy. The results highlighted the importance of considering the degree of advancement when planning orthognathic surgery and managing postoperative outcomes.

Quantifying bone healing after mandibular displacement in orthognathic surgery

Impaired bony healing following bilateral sagittal split osteotomy (BSSO) is a major unmet medical need for affected patients, and rare occurrences can hinder the identification of underlying risk factors. We hypothesised that osseous union following BSSO can be quantified using volumetric analysis, and we aimed to identify the risk factors for impaired bone healing. The percentage change in bony volume was measured in orthognathic patients following BSSO using two consecutive postoperative cone-beam computed tomography scans. Patients’ characteristics and treatment parameters were documented, and correlation and regression analyses of these variables performed. Thirty-six patients (23 men and 13 women) with a mean (SD) age of 33.28 (11.86) years were included. The gap site (lingual versus buccal) (p < 0.01) had a significant impact on the change in volume. Age (p = 0.06) showed a trend towards significance. Initial width of the osteotomy gap, sex, and indication for surgery did not influence osseous healing. Increased age at surgery and the side of the buccal osteotomy are independent risk factors for impaired osseous healing following BSSO.

Thematic Analysis of Parental Experiences of Patients' Orthognathic Surgery.

Orthognathic surgery often requires extensive orthodontic preparation and a prolonged postoperative recovery that can be stressful for patients and their families. Parents are a primary source of support for patients; accordingly, a better understanding of the parents' experience of orthognathic surgery can help inform clinical care. Using a prospective cross-sectional qualitative study design, 4 focus groups (2 English and 2 Spanish; mean length 65 min) were held with parents of patients who had completed orthognathic surgery for class II/III malocclusion. Thematic content analysis of the group transcriptions was conducted. Participants were 10 mothers and 3 fathers of 12 children (50% with cleft lip/palate) ages 17 to 23 who completed LeFort I (41.7%), LeFort I with bilateral sagittal split osteotomy (BSSO; 41.7%), or BSSO (16.7%) within the prior 3 to 16 months. Themes fit within a chronological framework: (1) Preparing for Surgery included their larger health context, anticipating surgery, surgery preparation by team and family, and religious faith; (2) Challenges after Surgery consisted of complications, pain, frustration, nutritional challenges, parental anxiety, activity changes, sleep, breathing issues, swelling, and unanticipated aspects of surgery; and (3) Supports after Surgery were nutritional support, appreciation of medical team, postoperative improvements, appearance changes, communicating, supporting patient, and patient coping. Parents also offered advice for families and medical teams. Surgeons and other providers who are part of orthognathic surgical preparation can implement recommendations based on parental experiences to increase patient and family readiness for surgery by providing early education, assisting with advocacy, focusing on nutrition, and supporting coping.

Long-term Skeletal Stability of Mandibular Surgery with Bilateral Sagittal Split Ramus Osteotomy—Advancement Versus Setback: A Systematic Review and Meta-analysis

Objectives The aim of this study was to evaluate and compare the long-term skeletal stability of mandibular advancement and mandibular setback achieved with bilateral sagittal split ramus osteotomy (BSSRO) procedure in adult patients with a minimum follow-up of at least 1 year. Methods A literature search was systematically performed according to PRISMA guidelines from four databases without limitation till 15 June 2021. Available literature was assessed for long-term skeletal stability as horizontal/vertical changes at cephalometric point B following conventional mandibular surgery (BSSRO) with rigid internal fixation. The quality of selected articles was assessed using Newcastle–Ottawa scale and the meta-analysis was carried out with Q statistic method, I-squared statistics, and fixed-effect model to estimate the pooled mean and Begg–Mazumdar bias indicator. Results A total of five studies (three pertaining to mandibular advancement and two setback groups) were included for comparative evaluation of relapse. The mean horizontal relapse was 7.85% pertaining to mandibular advancement (4.2–7.06 mm) as compared to 27% pertaining to mandibular setback (7.18–10.26 mm). The meta-analysis of four included studies (two in each group) revealed significant differences in long-term skeletal stability of mandibular advancement and setback (pooled proportion = 20.10; 95% confidence interval = 2.48–39.57). Conclusion Mandibular setback can be expected to relapse by 21.7–32.3% (mean 27%) as compared to mandibular advancement accounting for a relapse of 2.1–15.4% (mean 7.85%) in adult patients. Hence, mandibular advancement is a relatively stable procedure in the long term. PROSPERO registration number: CRD42021261466

Radiological evaluation of inferior alveolar nerve displacement after removal of impacted mandibular third molars prior to sagittal split osteotomy

IntroductionWe hypothesize that the removal of mandibular third molars (M3) 6 months prior to a bilateral sagittal split osteotomy (BSSO) could allow the displacement of the inferior alveolar nerve (IAN) in a favorable lingual position. This study aimed to radiographically compare the position of IAN before and after M3 removal in patients with Class II malocclusion. Materials and methodThe CBCT images of 30 randomly selected patients (mean age 15.5 years, 19 females and 11 males) were segmented regarding the mandibular bone and the IAN canal. Mandibles were then superimposed and compared using 3D slicer (www.slicer.org). An orthonormal system was constructed, and the coordinates of IAN were assessed in the x- (horizontal axis), y- (depth axis), and z- (vertical axis) directions. ResultsThe mean changes in x- and z-values were 0.37 %, -0.09 % for the right IAN, 0.07 %, and -0.10 % for the left IAN, respectively. Y-axis was the dimension the most impacted by the M3 removal with a mean variation of -11.96 % for the right IAN, and 0.45 % for the left nerve (p1=0.74 and p2=0.04, respectively). Three patients presented a change in the IAN position superior to 1 mm on at least one coordinate axis. We observed a more important change in x-values of the right IAN in male than in female (p = 0.04), and no significant modifications regarding the other dimensions. Finally, there was no correlation between the age of the patients and the changes in IAN position. ConclusionThis study confirms the absence of influence of mandibular third molar removal on the inferior alveolar nerve route prior to BSSO.

Surgical growth modulation for mandibular retrognathism: A case report

A case of 18-year-old female presented with retrognathic mandible having skeletal class II malocclusion, exhibiting convex profile, deep mentolabial sulcus, class II molar, and canine relation bilaterally with proclined maxillary incisors, increased overjet and 100% deep bite. The case had a severe ABO discrepancy index. The leveling and alignment of dental arches were achieved by sequential archwire placement using 0.022” MBT PEA. After leveling and alignment stage, the case was assessed for surgical growth modulation using intra-oral distractors. After necessary planning the case was operated for bilateral sagittal split osteotomy and placement of intra-oral distractors. A standardized protocol was followed for the activation of distractors. Two weeks post distraction the case was reassessed for skeletal changes achieved, followed by settling of occlusion and removal of intra-oral distractors. Skeletal class I bases with improvement in vertical proportions was observed on completion of treatment. This case report suggests that in a patient with mandibular retrognathism and nearly exhausted growth potential, orthodontic treatment in conjunction with meticulously planned and executed mandibular distraction osteogenesis may be effective in achieving aesthetic enhancement and improved stomatognathic function.

Risk factors for postoperative infection after bilateral sagittal split ramus osteotomy: A retrospective analysis

BackgroundThis retrospective clinical study investigated risk factors for infection following bilateral sagittal split ramus osteotomy (BSSO) as orthognathic surgery, including the patients' general condition, local factors, and surgical factors. Patients and methodsThe cases of 160 mandibular sites of 80 Japanese patients (26 males, 54 females; mean ± SD age: 25.3 ± 7.7 years, range 16–55 yrs) with a jaw deformity who underwent BSSO orthognathic surgery at our Department of Oral and Maxillofacial Surgery between Jan. 2017 and Dec. 2022 were analyzed. Potential risk factors were classified as clinical predictive variables. Descriptive and univariate statistics were computed. A multivariate analysis was performed with logistic regression. ResultsFifteen mandibular sites (9.4 %) were complicated with postoperative infection. The multivariate analysis revealed significant differences in facial asymmetry (OR 24.0, p = 0.0002) and the amount of mandibular movement (OR 0.664, p = 0.011) between the sites with and without infection. ConclusionsAmong clinical variables, facial asymmetry was the strongest risk factor for post-BSSO infection, followed by the amount of mandibular movement.

Three-dimensional evaluation of skeletal stability after surgery-first bimaxillary surgery for class III asymmetry in 70 consecutive patients

Background/purposeSkeletal stability after orthognathic surgery is essential for positive treatment outcome. This study evaluated the stability of osteotomy segments after surgery-first bimaxillary surgery for class III asymmetry. Materials and methodsSeventy adults with class III asymmetry consecutively corrected through surgery-first Le Fort I and bilateral sagittal split osteotomies were investigated. Cone-beam computed tomography before treatment (T0), 1-week after surgery (T1), and after all treatment (T2, ≥1-year after surgery) was used to assess surgical movement (T0 to T1) and skeletal stability (T1 to T2) regarding the translation and rotation of the maxillary, mandibular distal, and proximal segments. ResultsAt T1, the maxillary segment had moved forward and upward, turned to the deviated side, and rotated downward (all P < 0.01). The distal segment of mandible had moved forward and upward and rotated upward (all P < 0.001). The deviated proximal segment had moved upward, tilted to the opposite side, and rotated upward (all P < 0.001). The opposite proximal segment had moved upward and tilted to the deviated side (both P < 0.01). At T2, significant relapse occurred in the mandible. The distal segment moved forward and upward and rotated upward (all P < 0.001). The deviated proximal segment moved upward, tilted to the opposite side, and rotated upward (all P < 0.001). The opposite proximal segment moved upward and tilted to the deviated side (both P < 0.01). ConclusionClinically significant relapse of class III asymmetry was discovered on the mandibular distal and opposite proximal segments.