Chang Gung Forum: An Exemplary Strategy for Implementing a Multidisciplinary Network of Experts in Craniofacial Anomalies.

INTRODUCTION: The Chang Gung Forum has been dedicated to the care of craniofacial anomalies since 2000. This annual continuing medical education program focuses on orofacial cleft and surgery-first orthognathic surgery by providing up-to-date information and management guidelines. This study explored how the Chang Gung Forum has influenced medical perspectives, decisions, and practices in a multidisciplinary craniofacial team. METHODS: Between 2000 and 2022, 20 Chang Gung Forums have been held. A questionnaire was distributed among 170 attendees who had participated in the forum more than once. The questionnaire collected information on the participants' experiences and levels of satisfaction with the educational program and whether or how it had influenced their clinical practice. RESULTS: Valid responses from 86 attendees (response rate, 50.6%) who had participated more than once were collected and analyzed. The overall satisfaction rate of the Chang Gung Forum based on the respondents' most recent visits was 4.28 ± 0.63 out of 5. Of the respondents, 90.9% acknowledged changes in their clinical practice, with modifications in surgery plans and decisions being the most notable (48.5%). In addition, comprehension increased throughout years of attending the annual forum (P < 0.001). CONCLUSION: The Chang Gung Forum has contributed markedly to the community of congenital craniofacial anomalies. The program will continue providing updated information and influencing the clinical decision-making of health care professionals.

Three-dimensional positioning of the maxilla using novel intermediate splints in maxilla-first orthognathic surgery for correction of skeletal class III deformity.

OBJECTIVES: Successful orthognathic surgery requires accurate transfer of the intraoperative surgical plan. This study aimed to (1) evaluate the surgical error of a novel intermediate splint in positioning the maxilla during maxilla-first orthognathic surgery and (2) determine factors influencing surgical error. MATERIALS AND METHODS: This prospective study examined 83 patients who consecutively underwent Le Fort I osteotomy for correction of skeletal class III deformity using a novel intermediate splint and a bilateral sagittal split osteotomy. Surgical error was the outcome variable, measured as the difference in postoperative translational and rotational maxillary position from the virtual plan. Measures included asymmetry, need and amount for mandibular opening during fabrication of intermediate splints, and planned and achieved skeletal movement. RESULTS: Mean errors in translation for vertical, sagittal, and transversal dimensions were 1.0 ± 0.7 mm, 1.0 ± 0.6 mm, and 0.7 ± 0.6 mm, respectively; degrees in rotation for yaw, roll, and pitch were 0.8 ± 0.6, 0.6 ± 0.4, and 1.6 ± 1.1, respectively. The transverse error was smaller than sagittal and vertical errors; error for pitch was larger than roll and yaw (both p < 0.001). Error for sagittal, transverse, and roll positioning was affected by the achieved skeletal movement (roll, p < 0.05; pitch and yaw, p < 0.001). Surgical error of pitch positioning was affected by planned and achieved skeletal movement (both p < 0.001). CONCLUSIONS: Using the novel intermediate splint when performing Le Fort I osteotomy allowed for accurate positioning of the maxilla. CLINICAL RELEVANCE: The novel intermediate splint for maxillary positioning can be reliably used in clinical routines.

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

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

Surgical Stability After Proximal Segment Angle Alteration in Patients With Class III Facial Asymmetry.

PURPOSE: Patients with facial asymmetry often seek improved symmetry in lower face contour resulting in transverse movement of the proximal segments. The study aimed to investigate the association between transverse change in the proximal segments and postoperative relapse after the surgical correction of skeletal Class III facial asymmetry. METHODS: This retrospective cohort study includes consecutive patients with skeletal Class III asymmetry who underwent 2-jaw orthognathic surgery. The primary predictor variable was ramus plane angle (RPA). The patients were grouped as small (S group, <4°) and large (L group, ≥4°) changes in RPA. The primary outcome was the positional change of B point, menton, and the intergonial width. Cone-beam computed tomography images were obtained before surgery (T0), 1 week after surgery (T1), and debond (T2). Intergroup comparison was conducted with independent t test. Correlations between the variables were estimated by Pearson correlation. RESULTS: The study sample was composed of 60 subjects with 30 subjects in each study group. In the S group, the mean surgical changes of RPA were inward rotated 0.91° bilaterally. In the L group, the mean surgical changes of RPA were inward rotated 4.80° and 0.32° on the deviated and non-deviated side. After surgery, further minor inward adaptation of both sides was noted (<1 mm), and intergonial distance reduced with these changes in the proximal segments. By comparing the postsurgical stability between S and L group, the overall sagittal and vertical stability had no significant difference between 2 groups. However, the postsurgical transverse menton relapse (ΔMe in T2-T1) was significantly larger in L group (0.81 ± 1.40 mm) than S group (0.04 ± 1.32 mm) by 0.77 mm (P = .014). CONCLUSION: Greater surgical changes in the proximal segments had minor clinical effect on transverse stability. Minor transverse overcorrection of 1 mm is recommended in cases with severe facial symmetry with extensive changes in the proximal segments.

Outcomes of alveolar cleft repair in complete cleft lip and palate after tertiary gingivoperiosteoplasty and segmental Le Fort I osteotomy.

OBJECTIVES: Gingivoperiosteoplasty is often used for reconstruction of alveolar defects in infants with cleft lip and palate. This study aimed to examine outcomes of tertiary gingivoperiosteoplasty, which has not previously been investigated. MATERIALS AND METHODS: This prospective study included 11 adults with complete cleft lip and palate (n = 12 sites) who consecutively underwent segmental Le Fort I osteotomy and concomitant gingivoperiosteoplasty for correction of skeletal class III deformity, nasoalveolar fistula and alveolar cleft. Outcomes included clinical and radiographic evaluations of gingivoperiosteoplasty at the time of osteotomy (presence of nasoalveolar fistula, residual cleft defect and unsupported root ratio of cleft-adjacent teeth), and determination of influencing factors for the clinical success of alveolar cleft repair. Study variables included age, gender, pre-surgical orthodontic treatment and alveolar cleft width of cleft-adjacent canine and angulation between cleft-adjacent teeth before surgery and 1-week postsurgery. RESULTS: Posttreatment, no nasoalveolar fistula remained. The residual cleft defect decreased significantly (p < 0.01). The unsupported root ratio of cleft-adjacent teeth did not differ (p > 0.05); eight cleft sites reached Bergland I or II (67% success). One-week postsurgery, the minimal alveolar cleft width of cleft-adjacent canine was significantly less in the success group compared with the failed group (p = 0.01). CONCLUSIONS: Tertiary gingivoperiosteoplasty and segmental Le Fort I osteotomy decreased nasoalveolar fistulas and induced alveolar bone formation. The minimal alveolar cleft width immediately after surgery was the major influencing factor of clinical success. CLINICAL RELEVANCE: Segmental Le Fort I osteotomy with simultaneous gingivoperiosteoplasty efficaciously repairs adult alveolar clefts.

Skeletal stability after bimaxillary surgery with surgery-first approach for class III asymmetry is not related to virtual surgical occlusal contact.

OBJECTIVES: Surgery-first orthognathic surgery is rarely used in class III asymmetry due to concerns of reduced skeletal stability from unstable surgical occlusion. This study aimed to evaluate if skeletal stability after surgery-first orthognathic surgery is related to virtual surgical occlusal contact or surgical change. MATERIALS AND METHODS: We studied 58 adults with class III asymmetry, consecutively corrected by Le Fort I osteotomy and bilateral sagittal split osteotomy using a surgery-first approach. Dental casts were manually set to measure virtual surgical occlusal contact including contact distribution, contact number, and contact area. Cone-beam computed tomography taken before treatment, 1-week post-surgery, and after treatment was used to measure surgical change and post-surgical stability of the maxilla and mandible in translation (left/right, posterior/anterior, superior/inferior) and rotation (pitch, roll, yaw). The relationship between skeletal stability and surgical occlusal contact or surgical change was evaluated with correlation analysis. RESULTS: Significant instability was found in the mandible but not in the maxilla. No correlation was found between the maxillary or mandibular stability and surgical occlusal contact (all p > 0.01). However, a significant correlation was found between the maxillary (roll and yaw) or mandibular (shift, roll and pitch) stability and its surgical change (all p < 0.001). CONCLUSIONS: In correction of class III asymmetry with surgery-first bimaxillary surgery, the skeletal stability is not related to the virtual surgical occlusal contact, but surgical skeletal change. CLINICAL RELEVANCE: Planned over-correction is a reasonable option for correction of severe shift or roll mandibular asymmetry in bimaxillary surgery for class III deformity.

Type of mandibular asymmetry affects changes and outcomes of bimaxillary surgery for class III asymmetry.

OBJECTIVES: Various methods have been used to classify class III asymmetry. There is little information on the use of an asymmetry index to examine soft tissue changes and outcomes for patients with class III asymmetry. This study aimed to (1) evaluate soft tissue changes and outcomes for three types of mandibular asymmetry and (2) determine if measures are associated with type of asymmetry. MATERIALS AND METHODS: Adults who consecutively underwent bimaxillary surgery using surgery-first approach for correction of class III asymmetry were divided into three groups based on type of mandibular asymmetry. This previously reported classification system is simple and mutually independent, categorizing mandibular asymmetry according to the amount and direction of ramus asymmetry relative to menton deviation: patients with a larger transverse ramus distance on the menton deviation side were divided into group 1 and group 2; group 1 (n = 45) exhibited a menton deviation larger than ramus discrepancy; group 2 (n = 11) exhibited a menton deviation less than ramus discrepancy; group 3 (n = 22) had larger transverse ramus distance contralateral to the side of the menton deviation. Soft tissue facial asymmetry indices, calculated from cone beam computed tomography images, assessed midline and contour asymmetry presurgery, changes postsurgery, and outcomes. RESULTS: Compared with groups 1 and 2, the presurgery index for contour and midline asymmetry was smallest for group 3. All the three groups had significant improvement in midline asymmetry postsurgery, and outcome measures were good; there were no differences between groups. However, contour asymmetry only improved significantly for groups 1 and 2. The outcome for contour asymmetry was fair for groups 1 and 3 and poor for group 2. CONCLUSIONS: Bimaxillary surgery significantly improved facial midline asymmetry. The type of mandibular asymmetry was associated with postsurgical changes and outcomes for contour asymmetry. CLINICAL RELEVANCE: Understanding the types of mandibular asymmetry could help clinicians to develop treatment plans and predict treatment changes and outcomes.

Skeletal and upper airway stability following modified maxillomandibular advancement for treatment of obstructive sleep apnea in skeletal class I or II deformity.

OBJECTIVES: Maxillomandibular advancement (MMA) is an effective short-term treatment for obstructive sleep apnea (OSA). This study aimed to evaluate the long-term stability of the facial skeleton, upper airway, and its surrounding structures, as well as improvement in OSA following MMA. MATERIALS AND METHODS: Thirty-one adults with moderate-to-severe OSA underwent surgery-first modified MMA as primary surgery. Polysomnography and cone-beam computed tomography were obtained pre-surgery, early post-surgery, and at follow-up (i.e., ≥ 2 years post-surgery). Image analysis software assessed the facial skeleton, upper airway, and its surrounding structures. RESULTS: Early post-surgery, apnea-hypopnea index (AHI) had decreased significantly (p < 0.001) and the minimum oxygen saturation (MSAT) increased (p = 0.001), indicating significant improvement in OSA. At follow-up, the AHI and MSAT remained stable. However, the anterior maxilla, soft palate, and tongue moved backward while the hyoid moved downward. There was also a significant decrease in the minimal cross-sectional area of the oropharynx. The reduction in AHI was significantly related to the anterior movement of the anterior maxilla and tongue, inferior movement of the posterior maxilla, and superior movement of the soft palate tip. CONCLUSIONS: The improvement of OSA after modified MMA remained stable for at least 2 years following treatment, despite the relapse of the facial skeleton, upper airway, and its surrounding structures. The reduction of AHI was not related to changes in the caliber of the upper airway but to the movement of the maxilla, soft palate, and tongue. Clinical relevance Modified MMA is clinically effective for long-term treatment of patients with moderate-to-severe OSA.

Comparison of stability and outcomes of surgery-first bimaxillary surgery for skeletal class III deformity between unilateral and bilateral cleft lip and palate.

OBJECTIVES: Some adults with cleft lip and palate (CLP) require orthognathic surgery due to skeletal deformity. This prospective study aimed to (1) compare skeletal stability following bimaxillary surgery for correction of class III deformity between patients with unilateral CLP (UCLP) and bilateral CLP (BCLP), and (2) identify risk factors of stability. MATERIALS AND METHODS: Adults with CLP and skeletal class III deformities who underwent surgery-first bimaxillary surgery were divided into two groups according to cleft type: UCLP (n = 30) and BCLP (n = 30). Skeletal stability was assessed with measures from cone beam computed tomography images of the maxilla and mandible taken before treatment, 1-week and ≥ 1 year postsurgery for translation (left/right, posterior/anterior, superior/inferior) and rotation (yaw, roll, pitch); multiple regression analysis examined risk factors. RESULTS: At follow-up, the maxilla moved upwards in both groups, and backwards in the UCLP group. The mandible moved forward and upward, shifted to the cleft (deviated) side, and rotated upward in both groups. The amount of surgical advancement was a risk factor for sagittal stability in the maxilla (ß = -0.14, p < 0.05). The mandible had three risk factors for sagittal stability: age (ß = -0.23, p < 0.05), surgical team (ß = -1.83, p < 0.05), and amount of surgical setback (ß = -0.32, p = 0.001). CONCLUSIONS: Two years after bimaxillary surgery, patients with UCLP had a higher sagittal relapse of the maxilla compared with patients with BCLP, which was due to a greater surgical advancement in the patients with UCLP. CLINICAL RELEVANCE: Surgery-first bimaxillary surgery results in favorable treatment outcomes for correction of cleft-related class III deformity. Severity of jaw discrepancy and surgeons should be considered in the surgical design of overcorrection.

Dynamic changes in genetic diversity, drug resistance mutations, and treatment outcomes of falciparum malaria from the low-transmission to the pre-elimination phase on the islands of São Tomé and Príncipe.

BACKGROUND: With effective vector control and case management, substantial progress has been made towards eliminating malaria on the islands of São Tomé and Príncipe (STP). This study assessed the dynamic changes in the genetic diversity of Plasmodium falciparum, the anti-malarial drug resistance mutations, and malaria treatment outcomes between 2010 and 2016 to provide insights for the prevention of malaria rebounding. METHODS: Polymorphic regions of merozoite surface proteins 1 and 2 (msp1 and msp2) were sequenced in 118 dried blood spots (DBSs) collected from malaria patients who had visited the Central Hospital in 2010-2016. Mutations in the multi-drug resistance I (pfmdr1), chloroquine resistance transporter (pfcrt), and kelch 13 (pfk13) genes were analysed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing in 111 DBSs. A total of 7482 cases that completed a 28-day follow-up were evaluated for treatment outcomes based on the microscopic results. Regression models were used to characterize factors associated with levels of parasite density and treatment failures. RESULTS: Parasite strains in STP showed significant changes during and after the peak incidence in 2012. The prevalent allelic type in msp1 changed from K1 to MAD20, and that in msp2 changed from 3D7/IC to FC27. The dominant alleles of drug-resistance markers were pfmdr1 86Y, 184F, D1246, and pfcrt 76 T (Y-F-D-T, 51.4%). The average parasite density in malaria cases declined threefold from low-transmission (2010-2013) to pre-elimination period (2014-2016). Logistic regression models showed that patients with younger age (OR for age = 0.97-0.98, p < 0.001), higher initial parasite density (log10-transformed, OR = 1.44, p < 0.001), and receiving quinine treatment (compared to artemisinin-based combination therapy, OR = 1.91-1.96, p < 0.001) were more likely to experience treatment failures during follow-up. CONCLUSIONS: Plasmodium falciparum in STP had experienced changes in prevalent strains, and increased mutation frequencies in drug-resistance genes from the low-transmission to the pre-elimination settings. Notably, patients with younger age and receiving quinine treatment were more likely to show parasitological treatment failure during follow-up. Therapeutic efficacy should be carefully monitored to inform future treatment policy in STP.

What are the Effects of Age and Presence of Third Molars on the Occurrence of Unfavorable Splits During Sagittal Split Osteotomy?

PURPOSE: Several studies have investigated risk factors of unfavorable splits associated with sagittal split osteotomies but yielded conflicting information. The purpose of this study is to estimate the frequency of and identify factors associated with unfavorable splits during sagittal split osteotomies (SSOs). MATERIAL AND METHODS: A retrospective cohort study was conducted on patients who underwent orthognathic surgery, including SSOs at our institution from January 2010 to October 2016. The independent variables were mandibular third molar (M3) status, age, gender, and preoperative dentofacial diagnosis. The outcome variable was the effectiveness of the sagittal split resulting in either favorable or an unfavorable split. Data analyses were performed using logistic regression models except in the case of small sample sizes of preoperative dentofacial diagnoses for which the Fisher's exact test was used. RESULTS: A total of 888 patients with an average age of 24.97 ± 5.09 years underwent 1,776 SSOs. Sixteen (0.90%) unilateral unfavorable splits occurred. Unfavorable splits were less common in patients with an M3 present than in patients with the M3 absent. Having an M3 present reduced the chance of an unfavorable split by 69%, adjusted for age and gender; OR (95% CI) = 0.308 (0.103, 0.919); P = .035. The odds of having an unfavorable split were increased by 8.8% for every year of age increase; adjusted OR (95% CI) = 1.088 (1.004, 1.178); P = .038. Based on this estimation, a 45-year-old is 2.3 times more likely to have an unfavorable split compared to a 35-year-old (95% CI:1.041, 5.146), and is 5.4 times more likely to have an unfavorable split compared to a 25-year-old (95% CI:1.083, 26.48). CONCLUSIONS: The presence of a mandibular third molar (M3) was associated with a decreased risk of an unfavorable split, independent of age and gender. There was a significant association between increased age and the incidence of an unfavorable split.

Impact of the Different Types of Le Fort I Maxillary Surgical Movement on Nasal Width Changes: A Photogrammetric Analysis.

BACKGROUND: Le Fort I maxillary movements affect nasal width, but nasal width changes with specific movement types have not been formally addressed to date. OBJECTIVES: The purpose of this study was to analyze and compare the changes in nasal width with different maxillary movements. METHODS: A retrospective study was performed among consecutive patients who underwent bimaxillary orthognathic surgery (n = 138) and who were grouped based on the type of maxillary movement (ie, maxillary advancement with intrusion [MAI], maxillary advancement with extrusion [MAE], and maxillary setback with intrusion [MSI]). Preoperative and 12-month postoperative nasal widths were analyzed photogrammetrically by 2 blinded evaluators. RESULTS: Maxillary advancement with intrusion and MAE presented a significantly (P < 0.05) higher alar base widening than MSI did, with no significant (P > 0.05) differences between MAI and MAE. Maxillary advancement movements (MAI and MAE) showed significantly (P < 0.05) higher alar base widening than maxillary setback movement (MSI). However, no significant (P > 0.05) difference was observed between maxillary intrusion (MAI and MSI) and maxillary extrusion (MAE) movements. CONCLUSIONS: This study shows that the nasal width varies distinctly depending on the type of Le Fort I maxillary surgical movement.

One-splint versus two-splint technique in orthognathic surgery for class III asymmetry: comparison of patient-centred outcomes.

OBJECTIVES: Two-jaw orthognathic surgery (OGS) is done using either the one-splint technique with free-hand positioning of the maxillomandibular complex or the two-splint technique with intermediate splints to position the maxilla. It is uncertain which technique achieves better outcomes. This study compares frontal soft tissue symmetry and subjective patient QoL between one-splint and two-splint techniques in skeletal Class III asymmetry patients undergoing OGS with three-dimensional surgical planning. MATERIALS AND METHODS: This retrospective case-control study comprised 34 one-splint and 46 two-splint OGS patients. Frontal photographs and Orthognathic Quality of Life Questionnaire (OQLQ) were done pre- and post-treatment. Frontal soft tissue symmetry was analysed with the anthropometric Facial Symmetry Index. Measurements were compared with t-tests and chi-squared tests with p-value set at 0.05. RESULTS: The groups differed in pre-treatment ANB and OQLQ scores. The two-splint group showed significant improvement in all symmetry measures. The one-splint group showed significant improvement in all symmetry measures except midface deviation, upper contour deviation and the Facial Contour Symmetry Index. Both groups showed significant improvement in OQLQ scores. There were no significant differences in post-treatment symmetry measurements and OQLQ scores between groups. CONCLUSIONS: Although two-splint technique may better improve contour symmetry, there were no significant differences in frontal soft tissue symmetry and QoL after OGS in skeletal Class III asymmetry with either one-splint or two-splint technique, with both techniques resulting in significant improvement. CLINICAL RELEVANCE: One-splint and two-splint surgical techniques produce similar patient-centred outcomes in Class III asymmetry patients.

Comparative stability and outcomes of two surgical approaches for correction of class III asymmetry with lip or occlusal cant.

OBJECTIVES: To assess and compare the stability and outcomes of the two surgical approaches for patients with roll asymmetry. MATERIALS AND METHODS: A total of 50 adult patients were consecutively recruited for this prospective study. Patients with class III asymmetry and lip or occlusal cant who underwent bimaxillary surgery were grouped according to surgical approach: asymmetric posterior impaction on both sides (API, n = 31) and posterior impaction on one side and posterior extrusion on the other side (PIE, n = 19). Postsurgical stability and outcomes between groups were determined with cone-beam computed tomography for facial midline, lip, and occlusal cant at 1 week (T1), and at least 12-month postsurgery (T2, completion of orthodontic treatment). RESULTS: Presurgery, the upper anterior occlusal cant and lip cant were significantly greater for the PIE group (p < 0.05). Postsurgery (T2), the mandible moved upward and rotated upward in both groups. However, the upward rotation was significantly greater in the PIE group compared with the API group. Although the two approaches resulted in significant improvements in facial symmetry, the deviation in the facial midline remained under-corrected for most API patients. CONCLUSIONS: Patient outcomes for mandibular stability and facial symmetry differed between the two surgical approaches for correction of class III asymmetry with lip or occlusal cant. CLINICAL RELEVANCE: The findings of this study suggest that planned over-correction is a reasonable option for the approach of asymmetric posterior impaction on both sides.

History and Evolution of Orthognathic Surgery at Chang Gung Craniofacial Center: Lessons Learned From 35-Year Experience.

BACKGROUND: Modern orthognathic surgery (OGS) was established on the basis of contributions from multidisciplinary centers worldwide. This study reports the history and evolution of OGS at the Chang Gung Craniofacial Center (CGCC) and identifies the lessons learned from 35 years of experience. METHODS: The total number of OGS procedures managed by the CGCC multidisciplinary team between 1981 and 2016 was determined. The database of the senior author (Y.-R.C.) was reviewed for consecutive OGS procedures performed between 2003 and 2016. A literature review was also performed to retrieve the contributions from the total CGCC team. RESULTS: The 35 years of experience at a single center and 13-year experience of a single surgeon corresponded to 8073 and 2883 OGS procedures, respectively. Moreover, 53 peer-reviewed articles were reviewed. Teamwork (plastic surgeons, orthodontists, and anesthetists) ensured an optimal balance between occlusion functional and facial aesthetic outcomes, with patient safety ensured and a minimum of OGS-related complications. Progression from the conventional orthodontics-first approach to the surgery-first OGS approach decreased the overall treatment time. Transition from 1-jaw to 2-jaw surgery enabled more consistent aesthetic outcomes to be achieved. Conversion from the 2-splint to the single-splint technique enabled development of a more precise tridimensional simulation plan and surgical execution, including in challenging scenarios such as malocclusion associated with facial asymmetry. Clockwise pitch rotation of the maxillomandibular complex has been designed for facial aesthetic purposes in class III malocclusion, whereas counterclockwise pitch rotation of the maxillomandibular complex improves airway function in those with sleep apnea. CONCLUSIONS: The lessons learned from experience and outcome-based articles reveal that OGS has successfully evolved at the CGCC, with a balance being achieved between functional and aesthetic outcomes and effective decreases in the burden of care (ie, morbidity, complications, and treatment time).

Outcomes of conventional versus virtual surgical planning of orthognathic surgery using surgery-first approach for class III asymmetry.

OBJECTIVES: To determine if patient outcome variables differ between conventional and virtual surgical planning of orthognathic surgery for class III asymmetry. MATERIAL AND METHODS: This retrospective case-control study examined 95 patients with class III asymmetry who had been consecutively treated with at least a Le Fort I osteotomy and a bilateral sagittal split osteotomy with a surgery-first approach. Two groups were examined: 51 patients treated with conventional surgical planning and 44 with virtual surgical planning. After treatment, quantitative assessment was determined with measurements of midline symmetry, contour symmetry, and overall facial symmetry using standardized frontal photographs. Subject assessments were analyzed with questionnaires regarding self-perception of overall appearance, satisfaction with appearance, and quality of life. RESULTS: Conventional and virtual surgical planning resulted in significant improvements in outcomes for all patients. However, facial midline and overall facial symmetry were significantly greater for the virtual compared with the conventional group. There were no significant differences in subjective measures of appearance, satisfaction with appearance, and quality of life for patients treated with conventional or virtual surgical planning; measures were high for both groups. CONCLUSIONS: Conventional and virtual surgical planning of surgery-first bimaxillary orthognathic surgery resulted in quantitative and qualitative improvements in facial symmetry. Although patient satisfaction was similar for both approaches, virtual surgical planning was superior to conventional surgical planning for the improvement of midline and overall asymmetry. CLINICAL RELEVANCE: Improvements with virtual surgical planning in facial midline, facial contour, and overall facial symmetry are as good as or better than conventional surgical planning.

A new 3D analysis on displacement of proximal segment after bilateral sagittal split osteotomy for class III asymmetry.

OBJECTIVES: We aimed to quantify the displacement of the proximal segment after bilateral sagittal split osteotomy in patients with class III asymmetry and evaluate if the displacement was related to the movement of the distal segment. MATERIAL AND METHODS: Forty adults with class III asymmetry corrected by bimaxillary surgery were studied. Cone-beam computed tomography taken before and 1 week after surgery was used to measure the displacement of proximal segments and movement of the distal segment in terms of translation and rotation. The relationship between the displacemnt of the proximal segment and the movement of the distal segment was evaluated. RESULTS: After surgery, the deviated proximal segment was displaced forward and to the deviated side, rotated downward, tilted, and turned to the opposite side. The opposite proximal segment was displaced forward and rotated downward. The roll rotation of the proximal segment was correlated with the left/right movement and roll rotation of the distal segment. CONCLUSION: Early after orthognathic correction for class III asymmetry, the deviated proximal segment was displaced in a direction favorable for correction of asymmetry. The roll rotation of the proximal segment was affected by the transverse movement and roll rotation of the distal segment. CLINICAL RELEVANCE: Knowledge of the ability and limitation of the proximal segment rotation improves the virtual simulation.

Effects of indoor residual spraying and outdoor larval control on Anopheles coluzzii from São Tomé and Príncipe, two islands with pre-eliminated malaria.

BACKGROUND: Vector control is a key component of malaria prevention. Two major vector control strategies have been implemented in São Tomé and Príncipe (STP), indoor residual spraying (IRS) and outdoor larval control using Bacillus thuringiensis israelensis (Bti). This study evaluated post-intervention effects of control strategies on vector population density, composition, and knockdown resistance mutation, and their implications for malaria epidemiology in STP. METHODS: Mosquitoes were collected by indoor and outdoor human landing catches and mosquito light traps in seven districts. Mosquito density was calculated by numbers of captured adult mosquitoes/house/working hour. Mitochondrial cytochrome c oxidase subunit I (COI) was PCR amplified and sequenced to understand the spatial-temporal population composition of malaria vector in STP. Knockdown resistance L1014F mutation was detected using allele-specific PCR. To estimate the malaria transmission risks in STP, a negative binomial regression model was constructed. The response variable was monthly incidence, and the explanatory variables were area, rainfall, entomological inoculation rate (EIR), and kdr mutation frequency. RESULTS: Malaria vector in STP is exophilic Anopheles coluzzii with significant population differentiation between Príncipe and São Tomé (mean FST = 0.16, p < 0.001). Both vector genetic diversity and knockdown resistance mutation were relatively low in Príncipe (mean of kdr frequency = 15.82%) compared to São Tomé (mean of kdr frequency = 44.77%). Annual malaria incidence rate in STP had been rapidly controlled from 37 to 2.1% by three rounds of country-wide IRS from 2004 to 2007. Long-term application of Bti since 2007 kept the mosquito density under 10 mosquitoes/house/hr/month, and malaria incidence rate under 5% after 2008, except for a rising that occurred in 2012 (incidence rate = 6.9%). Risk factors of area (São Tomé compared to Príncipe), rainfall, outdoor EIR, and kdr mutation frequency could significantly increase malaria incidence by 9.33-11.50, 1.25, 1.07, and 1.06 fold, respectively. CONCLUSIONS: Indoor residual spraying could rapidly decrease Anopheles density and malaria incidence in STP. Outdoor larval control using Bti is a sustainable approach for controlling local vector with exophilic feature and insecticide resistance problem. Vector control interventions should be intensified especially at the north-eastern part of São Tomé to minimize impacts of outbreaks.

Enhanced Surgical Outcomes in Patients With Skeletal Class III Facial Asymmetry by 3-Dimensional Surgical Simulation.

PURPOSE: With the advance of image fusion techniques, the creation of 3-dimensional (3D) virtual head and 3D surgical simulations has provided previews of surgical procedures. The aim of this study was to investigate the surgical outcomes in patients receiving orthognathic surgery (OGS) with the guidance of 3D computer-assisted surgical simulation. PATIENTS AND METHODS: The study included 34 consecutive patients (15 men and 19 women; age, 18.1 to 33.0 yr) with skeletal Class III facial asymmetry who underwent bimaxillary OGS. One-week postoperative cone-beam computed tomographic craniofacial images (Ta) were constructed and superimposed on preoperative simulated virtual images (Ts) at the cranial base and surfaces of the frontal and periorbital regions. The 3D cephalometric landmarks were measured relative to 3 reference planes. The outcomes among different experience levels of surgeons also were compared. RESULTS: Although the mean values between Ta and Ts were small, statistical differences were observed in the center of maxillary and mandibular incisors and the B point relative to the midline and in the maxillary first molar in vertical distances, sagittal dentoskeletal dimensions, and pitch angles. The root mean square deviations (RMSDL) of measurement variables relative to center landmark accuracy were 1.5 and less than 2 mm at the maxilla and mandible, respectively. RMSDL greater than 2 mm was located at the maxillary first molar in the vertical distance and in the sagittal dimension at the anterior nasal spine and B point. Variables related to centering the midline structures were highly inter-related. The roll angle deviation was associated with centering the midline landmarks. The yaw angle deviation was not associated with midline correction. CONCLUSION: With guidance from 3D surgical simulation, surgeons could achieve similar outcomes to correct facial asymmetry regardless of their years of practice.