Condylar positional changes and remodeling following bimaxillary anterior segment osteotomy with and without Le Fort I osteotomy: a three-dimensional comparative analysis.

OBJECTIVE: To evaluate 3D condylar displacement and long-term remodeling following the correction of bimaxillary protrusion by anterior segment osteotomy (ASO) with and without Le Fort I surgery. MATERIALS AND METHOD: This retrospective study included 32 adults with bimaxillary protrusion who underwent ASO alone (group 1) or with concomitant Le Fort I osteotomy (group 2). Subject's computed tomography scans at basic (T0), immediate postoperatively (T1), and at 1 year or more follow-up (T2) were collected. The condyle displacement was measured at superior-inferior, lateromedially, and anteroposterior surfaces, while condyle remodeling was measured at the superior, lateral, anterior, medial, and posterior surfaces. All 3D analyses were performed using 3D Slicer software (4.11.2). RESULTS: At T1, 52.7%, 86.7%, and 94.4% of condyles in group 1 were displaced inferiorly, laterally, and posteriorly, respectively, as well as 75%, 89.2%, and 53.5% of condyles in group 2, which had not fully returned to the original preoperative positions at T2. Condylar remodeling was observed in both groups at T2, and no significant difference was found in the overall condylar volume between T1 and T2 in both groups. Patients in group 2 exhibited significant bone resorption at both lateral and anterior surfaces compared to group 1 (P = 0.000 and 0.01, respectively). CONCLUSION: This study's results demonstrated that ASO is associated with a degree of condylar changes even if the posterior mandible is not osteomized. The positional changes vary between bimaxillary ASO alone and those with simultaneous Le Fort I osteotomy. However, both groups' condyle volume remained stable at the long-term follow-up.

Three-dimensional radiographic assessment of different fixation methods stability after l-shaped osteotomy reduction malarplasty: A comparative retrospective study.

BACKGROUND: Reduction malarplasty (RM) is a common facial contouring procedure among Orientals. Currently, fixation methods selection and placement vectors are controversial. Therefore, this study aimed to evaluate the effect of different zygomatic complex fixation methods on surgical outcomes stability after RM. MATERIALS AND METHODS: In this retrospective study, 60 consented patients (120 operated zygoma) who met inclusion criteria were included. ITK-SNAP and 3D Slicer software were used to measure the displacement of the zygomatic complex using postoperative CTs (T1: one week and T2: six months). The region of interest included zygomatic body fixation methods (ZBFm), namely: two bicortical screws (2LS); an l-shaped plate with one bicortical screw (LPLS); an l-shaped plate with short-wing on the zygoma (LPwZ) and on the maxilla (LPwM), combined with zygomatic arch fixation methods (ZAFm), including Mortice-Tenon (MT); 3-hole plate (3HP); and short screw (SS). ANOVA test was used to compare the displacement values among ZBFm/ZAFm combinations. RESULTS: The 2LS and LPLS groups showed lower displacement than the single l-shaped plate (P< 0.001, P = 0.001), which performed better when the short-wing was fixated on the maxilla (0.9 ± 0.4 mm and 1.2 ± 0.6 mm respectively). CONCLUSION: After RM, the two-bridge fixation methods (2LS and LPLS) provide better stability than the single l-shaped plate. All ZAF methods showed similar stability when combined with 2LS or LPLS as zygomatic body fixation methods.

Three dimensional condylar positional and morphological changes following mandibular reconstruction based on CBCT analysis: a prospective study.

OBJECTIVE: This study aimed to evaluate the condylar positional changes following mandibular reconstruction with preservation of the condylar head using Cone-Beam Computed Tomography (CBCT). Also, to assess joint space changes and the overall volumetric space compared to the preoperative status. METHODOLOGY: This prospective study included 30 patients (60 joints) subjected to unilateral mandibular resection and reconstruction with preservation of the condylar head. The Helkimo index and preoperative (T1), two weeks postoperative (T2), and follow-up CBCTs (T3) after at least six months were gathered and processed to evaluate the condylar position and TMJ joint space using Anatomage Invivo 6. A student's t-test and repeated-measures ANOVA statistics were used. A P value of less than 0.05 was considered statistically significant. RESULTS: Thirty patients (14 males, 16 females) with a mean age of 40.01 ± 12.7 years (a range of 18.1-62.9 years) were included. On the tumor side, there were significant variances in the vertical and mediolateral condylar positions between the three-time points (T1, T2, T3). Immediately after the operation, the condyles were significantly displaced in a downward direction at T2, which became larger after the last follow-up period (T3) (p = 0.007). The condylar positions at the anteroposterior direction were relatively stable without significant differences between the three times points (p = 0.915). On the non-tumor side, the condylar positions were relatively stable in the mediolateral and anteroposterior positions. In the tumor side, all of the TMJ spaces were significantly increased in size following the mandibular reconstructions (T2 and T3). However, on the non-tumor side, the anterior, posterior, and medial joint spaces were significantly changed postoperatively. CONCLUSION: After mandibular reconstruction with condylar preservation, the condylar position and volumetric measurement immediately changed noticeably and continued to be a permanent change over time compared to relatively stable condyles on the non-tumor side. According to Helkimo index, patients become adapted to the postoperative changes without significant differences between the two sides.

Cupid's Bow Leveling and Preservation of Lip Height and Width: A Modified Rotation-Advancement Technique.

BACKGROUND: Several methods for cleft lip repair have been developed over time, with no clear method considered the standard. In the authors' department, the use of a modified rotation-advancement technique rather than the traditional rotation-advancement technique in unilateral complete cleft lip repair has increased over the past decade. This study aimed to determine which technique provides better outcomes. METHODS: This retrospective study was conducted by analyzing the preoperative and postoperative aesthetic nasal and labial anthropometric measurements of the frontal and basal views of 213 consecutive patients treated between October of 2013 and June of 2019. A total of 141 participants were treated with the traditional rotation-advancement technique, and 72 with the modified rotation-advancement technique. The inclusion criteria were nonsyndromic unilateral complete cleft lip repair with high-resolution, good-quality photographs; no presurgical nasoalveolar molding; no revision in the lip or nose areas; and at least 1 year of follow-up. RESULT: Patients who received the modified rotation-advancement technique had significantly improved Cupid's bow position and orientation ( P < 0.02 and P < 0.01, respectively) and enhanced vertical lip height symmetry ( P < 0.01) while preserving the lip width. The columellar length ( P < 0.03) and angulation ( P < 0.045) were also significantly improved, with enhanced nostril inclination in this group ( P < 0.06). CONCLUSIONS: According to the findings of the current study, modified rotation-advancement technique assisted surgeons in improving symmetrical leveling of the Cupid's bow and significantly aided in correcting lip height without compromising lip width. Moreover, the modified rotation-advancement technique resulted in better aesthetic nasal outcomes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Evaluation of the Properties of 3D-Printed Ti Alloy Plates: In Vivo and In Vitro Comparative Experimental Study.

Titanium (Ti)-based implants play a significant role in rigid internal fixation in maxillofacial surgery. No study has reported that three-dimensional-printed Ti alloy plates (3D-Ti plates) have comprehensively excellent properties similar to standard plates (Matrix-MANDIBLE, SYNTHES, Switzerland) (Synthes-Ti plates). In this work, we manufactured 3D-Ti plates by selective laser melting with Ti6Al4V powder. The surface morphology, mechanical properties, and bone-plate contact rate of the 3D-Ti plates and the Synthes-Ti plates were characterized and compared via electron microscopy, atomic force microscopy, Vickers hardness test, three-point bending test, and software calculation. Human bone marrow stromal cells (HBMSCs) were cultured on the plates to test their biocompatibility. Importantly, the 3D-Ti plates were placed into a mandibular fracture model to assess the effect of medical application for 4 and 24 weeks. The 3D-Ti plates were demonstrated to have similar biocompatibility and stability for rigid internal fixation with the Synthes-Ti plates, lower roughness (106.44 ± 78.35 nm), better mechanical strength (370.78 ± 1.25 HV10), and a higher bone-plate contact rate (96.9%). These promising results indicate the feasibility of using 3D-Ti plates for irregular shapes and complex anatomical structures in a clinical context.

Correlation between mandibular anatomy and bad split occurrence during bilateral sagittal split osteotomy: a three-dimensional study.

OBJECTIVES: This study aimed to find out the correlation between different anatomical parameters of the mandible and the occurrence of a bad split in patients who had undergone bilateral split sagittal ramus osteotomy (BSSRO). MATERIALS AND METHOD: At both the distal roots of the first molar (1) and the retromolar area (2), we measured the distance from the buccal margin of the inferior dental canal (IDC) to the buccal margin of the cortical bone (MCBC), the thickness of both buccal cortical (WBCB) and cancellous bone (WBCA), distance from the superior border of IDC to the alveolar crest (MCAC), buccolingual thickness (BLT), and thickness of cancellous bone (WCA). At the ramus, the distances between the sigmoid notch to the upper part of the lingula (SL) and the inferior border of the mandible (SIBM), the thickness of the ramus at the level of the lingula (BLTR), and the anteroposterior width of the ramus (APWR) were measured. The paired and independent t-tests were used when applicable, and a P-value < 0.05 was considered significant. RESULTS: MCBC1 showed a significant difference between bad and non-bad split sides (P = 0.037). Both WBCA1 and WBCA2 show the same significant difference (P = 0.023, 0.024). Similarly, WCA1 and WCA2 showed a statistical difference between the bad and non-bad split sides (P = 0.027, 0.036). There were no statistically significant differences between the compared sides of WBCB1, WBCB2, MCAC1, MCAC2, SIBM, APWR, SL, and BLTR. CONCLUSION: Narrow space between IDC and the buccal cortical margin, along with the decrease in the thickness of both buccal cancellous bone and total cancellous bone at the inferior border of the mandible along the course of SSRO, has been implicated in the occurrence of bad split intraoperatively.

Morphological changes of TMJ disc in surgically treated ADDwoR patients: a retrospective study.

BACKGROUND: This study aimed to quantify the morphological changes of temporomandibular joint (TMJ) discs after disc repositioning surgery using the three-dimensional (3D) modeling. METHODS: Thirty patients who diagnosed with unilateral ADDwoR were included to compare the morphological differences between ADDWoR discs and normal discs, and fifteen patients who experienced unilateral or bilateral disc repositioning surgery were included to analyze the morphological changes before and after disc repositioning surgery. Disc 3D reconstruction and analyses were performed using magnetic resonance imaging (MRI) data. RESULTS: In the unilateral ADDwoR patients, volume, superficial area, length, and maximum longitudinal-sectional area of the ADDwoR disc were significantly smaller compared with the non-affected discs. However, there was no significant difference in width and cross-sectional areas between ADDwoR discs and non-affected discs. In patients who subjected to disc repositioning surgery, disc volume, superficial area, length, width and maximum longitudinal-sectional area of TMJ discs were markedly increased 6 months after surgery. CONCLUSIONS: This study demonstrated that the TMJ discs tended to be morphologically smaller in volume and shorter in length under ADDwoR status. Importantly, the ADDwoR discs tended to morphologically recover toward non-affected discs after 6 months follow-up following TMJ disc repositioning surgery.

Influence of Inferior Alveolar Nerve Exposure During Sagittal Split Osteotomy on the Rate and Timing of Baseline Sensory Recovery.

PURPOSE: Neurosensory disturbance is the most common consequence of sagittal split osteotomy (SSO). The purpose of this study is to quantitatively assess neurosensory deficiency and recovery to the preoperative status when the inferior alveolar nerve (IAN) was exposed versus unexposed during SSO. METHODS: This is a single-center, prospective, cohort study of all patients undergoing bilateral SSO between August 2018 and July 2019. Patients were included in the study sample if they underwent bilateral SSO with an intact intraoperative IAN and were received follow-up assessment for at least a year. The predictor variable was the intraoperative IAN status (exposed vs unexposed). The outcomes of interest were the rate and timing of recovery to the preoperative status. The covariates were age, sex, and the magnitude and direction of surgical movements. Neurosensory function was quantitatively evaluated using the Semmes-Weinstein monofilament test at follow-up intervals of 1, 3, 6, and 12 months. Descriptive statistics, bivariate statistics, Cox proportional hazards regression, and Kaplan-Meier analyses were performed. P value <.05 was considered statistically significant. RESULTS: Of 90 patients, 86 patients who underwent 172 SSOs were included in this study. The mean age was 22.95 ± 3.34 years (range, 17 to 30), 65 were women, and the range of surgical movements was 3 to 8.3 mm of advancement and 2 to 12 mm of setback. Eighty-five nerves (49.4%) were allocated to the unexposed group, and 87 (50.6%) to the exposed group, with statistically significant differences in the rate and timing of recovery (hazard ratio = 2.368; 95% confidence interval, 1.662 to 3.376; P < .001). Among those with recovered nerves, the median time to recovery was 90 days in the unexposed group and 364 days in the exposed group (P < .0001). CONCLUSIONS: IAN exposure during SSO is associated with an increased risk of neurosensory deficiency and an increased time of sensory recovery to the baseline threshold in patients aged 17 to 30 years. When the IAN remained fully enclosed in the canal of the distal segment, only 11% of patients had a measurable sensory deficit 1 year after surgery. In those patients with any degree of IAN exposure, 36% had a residual sensory deficit 1 year after surgery.

Long-term three-dimensional condylar remodeling during presurgical orthodontics and after orthognathic surgery of mandibular retrognathia with high mandibular plane angle.

OBJECTIVES: Patients with high mandibular plane facial morphology are the most dominant facial type who experience TMJ abnormalities with resultant condylar resorption, affecting the orthodontic and orthognathic treatment outcomes. The study aimed to quantitatively assess the three-dimensional condylar remodeling during the presurgical orthodontics and after orthognathic surgery of the retrognathic mandible with a high mandibular plane angle. The study also investigated the correlation between the resultant remodeling based on the hypothesis that condylar resorption following orthognathic surgery is a part of a progressive presurgical resorption process. MATERIALS AND METHODS: The study included adults with mandibular retrognathism and high mandibular plane angle who have computed tomography scans (CT) obtained before any treatment (T0), after completion of presurgical treatment before surgery (T1), and at long-term follow-up after surgery (T2). DICOM of CT scan was gathered and processed using ITK-SNAP and 3D Slicer software. The interval between T0 and T1 was represented as a presurgical phase, while between T1 and T2 was defined as a postsurgical phase (T1-T2). RESULTS: Twenty-five patients (50 condyles) were included with a mean age of 23 ± 3.2 years. The mean of the follow-up during the presurgical phase was 19.8 ± 7.1 months and 15.5 ± 5.5 months during the postsurgical phase. The condylar volume during the presurgical phase (T0-T1) was relatively stable (- 3.3 ± 37.2mm3). However, during the postsurgical phase (T1-T2), the volume was significantly reduced - 113.8 ± 98.3mm3 (P < 0.001). Localized condylar surface resorption during the postsurgical phase was significantly higher than during the presurgical phase (P < 0.05). No correlation was found between the localized condylar surface remodeling during the presurgical and postsurgical phases. However, a negative statistically significant correlation existed between the overall condylar volume changes during the presurgical and postsurgical phases (r = 0.502, P < 0.001). CONCLUSION: Significant condylar resorption following orthognathic surgery of the retrognathic mandible with a high mandibular plane angle might occur regardless of the presurgical status of the condyle. CLINICAL RELEVANCE: The study provided an evidence to be discussed with the patients and considered throughout the treatment of mandibular retrognathia with high mandibular plane angle.

Analysis of Environmental Exposures for Nonsyndromic Cleft Lip and/or Palate: A Case-Control Study.

Background: Orofacial cleft is among the most common developmental malformations in humans. This study aimed to identify the relationship between environmental factors and nonsyndromic cleft lip and/or palate (NSCL/P) in Northwest China. Methods: This case-control study was conducted in Gansu Province, China over two years (Jan. 1, 2017-Jan. 1, 2019). Overall, 600 NSCL/P cases and 660 normal control cases were finally enrolled in the current study. Data were collected by conducting face-to-face interviews with both parents of each case. Results: Univariate (χ2) analysis revealed 22 factors as being significantly associated with NSCL/P. Multivariate (stepwise logistic regression) analysis identified that 14 factors had statistically significant association with NSCL/P. Male gender (OR=0.789), paternal age at childbirth of 25-29 yr (OR=0.690), and folic acid supplement (OR=0.197) were found to be protective factors against NSCL/P. On the other hand, blood A-type, multiple births, positive family history of NSCLP (OR=6.660), parental consanguinity (OR=6.107), positive abortion history, high or low maternal childbearing age, and maternal passive smoking (OR=4.349), malnutrition (OR=4.431), infections, and drug use (OR=2.188) during early gestation were significant risk factors for NSCL/P. Conclusion: Parental age at childbirth of 25-29 yr, and folic acid supplement can reduce the risk of NSCL/P. By contrast, maternal passive smoking, infections, and drug use during early gestation period, and multiple births, parental consanguinity, positive family history, and maternal abortion history can increase the risk of NSCL/P. Identification of risk factors is essential in minimizing the incidence of NSCL/P in a particular population.

Correlation of the Chinese velopharyngeal insufficiency-related quality of life instrument and speech in subjects with cleft palate.

OBJECTIVE: Assessment of the hypothesized correlation between the Chinese Velopharyngeal Insufficiency (VPI) Effects on Life Outcomes (VELO) instrument and measured speech parameters. METHODS: A cross-sectional study was conducted in the Oral Clefts Center of West China Hospital of Stomatology between January 2019 and December 2019. Speech parameters including speech intelligibility deficit, VPI severity, VP gap, and need for speech therapy were evaluated by speech-language pathologists. All patients and their parents completed the VELO instrument. The correlation between aforementioned speech parameters and VELO scores was examined utilizing Spearman correlation coefficients. The reliability of VELO test-retest and parent proxy assessment was estimated utilizing intraclass correlation coefficients (ICC). A receiver operating characteristic curve was used to calculate the cutoff VELO score. RESULTS: One hundred and forty patients with their parents were enrolled. The mean age was 12.58 ± 3.72 years. Both parent and youth VELO total and domain scores recorded moderate to strong correlations with all speech parameters (r > -.40, P ˂ .001) except the swallowing domain. Most VELO domain items have shown significant correlations with at least one speech parameter. Moreover, the scales of all speech parameters showed different VELO scores (P Ë‚ .001). The ICC reported test-retest correlation >.73 in all domains, and parent proxy correlation >.63 in most domains except the emotional and perception domains. The cutoff VELO score was 79.04 in parent version and 85.77 in youth version. CONCLUSIONS: The correlations between VELO scores and measured speech parameters have provided evidence for test-retest and parent proxy reliability and criterion and construct validity of the Chinese version of the VELO instrument. A VELO score ≥79.04 (in parent version) or ≥85.77 (in youth version) mostly reflects proper speech-related quality of life. Hence, this instrument could serve as a simple tool to help clinicians understand the social, emotional, and physical influences of VPI.

Modified Rotational Advancement Technique for Primary Unilateral Complete Cleft Lip Repair.

Importance: Leveling Cupid's bow while maintaining lip height and width in unilateral complete cleft lip patients with improved nose outcomes is a significant challenge for surgeons. Objective: This study aimed to measure the symmetry of the nasal and labial anthropometric points after using this modified cleft lip repair technique. Design, Setting, and Participants: In this retrospective study, 72 consecutive nonsyndromic unilateral complete cleft lip patients underwent a modified rotational advancement technique. Photos of at least 1 year follow-up period were collected. Main Outcomes and Measures: The nose measurements included columella length, nostril height and width, ala width, nostril inclination, columella angle, and ala bases angle. The lip measurements included lip height and width, vermillion height; midline-philtrum angle, and angles of Cupid's bow peaks. Descriptive quantitative analysis of the lip and nose measurements, intraclass correlation coefficient, and ANOVA tests were conducted. Results: Well-aligned Cupid's bows with symmetrical lip height and width were obtained with satisfactory aesthetic nasal outcomes. Conclusions: The present technique had leveled the Cupid's bow while preserving the lip height and width, with resultant satisfactory nasal outcomes.

Three-dimensional assessment of accuracy for open reduction and internal fixation of the subcondylar fracture and its implications on the TMJ function.

This study used three-dimensional cone beam computed tomography (CBCT) to assist the accuracy of open reduction and internal fixation (ORIF) for the unilateral subcondylar fracture and the long-term temporomandibular joint (TMJ) function impairment. Bilateral TMJs were analyzed postoperatively on CBCT images, involving the following three-dimensional (3D) parameters: condylar position and inclination; circumferential joint space, ramus, and mandible length; and the volumetric joint space. The inclusion criteria for adult patients included having a displaced fracture >5°, a shortening in ramus length >2 mm, and mouth opening limitation. The non-fracture side was used as the comparison group. The Helkimo index was employed for the clinical assessment of the outcomes, while the paired student t-test and Pearson coefficient test were used to compare both sides. The study included 60 joints in 30 consecutive patients. The condylar inclination to the horizontal plane on the fracture and non-fracture sides was 9.29 ± 3.9°, 12.46 ± 4.2°, (p < 0.001) and was positively related to the subjective (Helkimo Hi) and objective (Helkimo Di) clinical outcomes. In contrast, the condylar position to the midsagittal plane in the fracture and non-fracture sides was 51.95 ± 3.5 mm, 50.17 ± 3.6 mm (P = 0.038), and was positively related to the objective outcomes. Additionally, the objective outcome was negatively related to the change of the posterior joint space. CONCLUSION: The three-dimensional assessments seem to demonstrate that the ORIF is an accurate approach for obtaining a three-dimensional reduction to the displaced subcondylar fracture.

Treatment measures of hemimandibular hyperplasia and associated facial deformities.

This study aims to show our institute's experience in the treatment of HH and its associated facial deformities in adults and growing adolescents and to investigate condylar remodeling and volumetric changes and long-term stability of orthognathic surgery in adults. The study included consecutive patients with clinical and radiological features of HH who underwent high condylectomy with or without simultaneous orthognathic surgery from 2013 to 2018. The clinical outcomes were assessed based on functional activities, TMJ pain, and recurrence. Postoperative 3D condylar remodeling and orthognathic stability were evaluated with the use of ITK-Snap and 3D Slicer. Thirteen patients (8 females and 5 males) with a mean age of 26.3 ± 5.79 years (range; 13-34 years) were included with facial asymmetry as the chief complaint. The patients were followed up for a minimum of 12 months and a maximum of 4 years (mean; 16.85 ± 10.04). There were no postoperative complications, and all patients achieved a satisfactory functional and aesthetic outcome using a one-stage surgical procedure. There was no incidence of recurrence or further asymmetries, with long-term stability at the selected points showing a mean difference of less than ±1 mm. The affected condylar volume was significantly reduced following high condylectomy, with mean changes between T1 and T2 of -144. 80 mm3 (p = .012). However, the contralateral condylar volume remained stable, with a mean change of 2.54 mm3 (p = .881). One-stage high condylectomy and orthognathic surgery is a viable measure for the treatment of HH and associated deformities in adults. High condylectomy in early adolescence could result in termination of the disease, and aesthetic improvement with further constant orthodontist-surgeon follow-up is required.

The quantitative correlation between condylar resorption and skeletal relapse following mandibular advancement in skeletal class II malocclusion patients.

OBJECTIVE: The purpose of this study was to analyze the quantitative correlation between condylar resorption and skeletal relapse after mandibular advancement surgery. MATERIALS AND METHODS: Skeletal Class II malocclusion patients who underwent bilateral sagittal split ramus osteotomy (BSSRO) were included. Three-dimensional reconstruction was based on one-week and one-year post-operative CT scans. The condylar morphological alterations were assessed by anterior-posterior, medial-lateral diameter and condylar height. The mandibular relapse was calculated by the positional changes of pogonion, menton, gonions, gnathion and mental foramens. All data were measured by MIMICS and analyzed by SPSS software; significance was set at p<0.05. RESULTS: 31 patients (62 condyles) were enrolled into this study. 28 of 62 condyles showed resorption beyond 1 mm on condylar height and 15 were beyond 2 mm. Positional changes of chin, mental foramens and gonion were respectively 1.57 ± 2.36 mm, 1.31 ± 1.23 mm and 1.42 ± 1.02 mm. 21 of 31 patients experienced mandibular relapse less than 1 mm but additional 4 patients showing relapse more than 2 mm. Correlation with moderate intensity could be observed between condylar height alteration and post-operative mandibular displacement more than 1 mm (p = 0.035). CONCLUSION: The resorption degree of condylar height can be regarded as a useful parameter for evaluating post-operative skeletal relapse.

The accuracy of three-dimensional rapid prototyped surgical template guided anterior segmental osteotomy

Background: Surgical guiding templates provided a reliable way to transfer the simulation to the actual operation. However, there was no template designed for anterior segmental osteotomy so far. The study aimed to introduce and evaluate a set of 3D rapid prototyping surgical templates used in anterior segmental osteotomy. Material and methods: From August 2015 to August 2017, 17 patients with bimaxillary protrusions were recruited and occlusal-based multi-sectional templates were applied in the surgeries. The cephalometric analysis and 3D superimposition were performed to evaluate the differences between the simulations and actual post-operative out-comes. The patients were followed-up for 12 months to evaluate the incidence rate of complications and relapse. Results: Bimaxillary protrusion was corrected in all patients with no complication. In radiographic evaluations, there was no statistically significant difference between the actual operations and the computer-aided 3D simulations (p > 0.05, the mean linear and angular differences were less than 1.32mm and 1.72° consequently, and 3D superimposition difference was less than 1.4mm). The Pearson intraclass correlation coefficient reliabilities were high (0.897), and the correlations were highly significant (P < 0.001).Conclusions: The 3D printed surgical template designed in this study can safely and accurately transfer the computer-aided 3D simulation into real practice

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What Is the Most Effective Rehabilitation Method for Posterior Maxillas With 4 to 8 mm of Residual Alveolar Bone Height Below the Maxillary Sinus With Implant-Supported Prostheses? A Frequentist Network Meta-Analysis.

PURPOSE: The most effective rehabilitation method for patients with edentulous posterior maxillas with an intermediate (4 to 8 mm) residual bone height (RBH) below the maxillary sinus is unclear. Evidence derived from conventional meta-analysis is limited because of the lack of head-to-head studies. This network meta-analysis (NMA) was performed to identify the most effective method to treat patients with intermediate posterior RBH. MATERIALS AND METHODS: An NMA of randomized controlled clinical trials (RCTs) was conducted to assess various rehabilitation methods using implant-supported prostheses for patients with intermediate posterior maxillary RBH (4 to 8 mm). Publications from 1970 through March 2018 in 3 major databases were searched. Parallel and split-mouth RCTs that reported the outcomes of interest with follow-up of at least 6 months from initial loading were included. Predictor variables were short implants (SIs; ≤8 mm) alone, SIs in conjunction with osteotome sinus floor elevation (OSFE) with or without bone grafting, long implants (LIs) in conjunction with OSFE with and without bone grafting, and LIs combined with lateral sinus floor elevation (LSFE) with bone grafting. Outcome variables were implant and prosthesis failure rates, marginal bone loss, and complications. Frequentist NMA was performed using STATA software. RESULTS: Twenty RCTs involving 770 patients with intermediate posterior maxillary RBH and 837 concerned maxillary sinuses who received 1,486 implants using any of the 4 rehabilitation methods were included. There were no statistically significant differences among the 4 groups for implant and prosthesis failure rates and marginal bone loss at follow-up (range, 6 months to 5 years after loading). There was a marked decrease in complications for SIs alone compared with LIs combined with LSFE. For implant and prosthesis survival rates, SIs in conjunction with OSFE with or without bone grafting ranked first as the most effective option (77.1%) followed by LIs plus OSFE with or without bone grafting (62%), LIs plus LSFE with bone grafting (43.9%), and SIs alone (24.8%). CONCLUSION: There is moderate-quality evidence derived from this NMA showing that OSFE combined with SI or LI placement with or without bone grafting or SI placement alone is superior to LI placement combined with LSFE and bone grafting when used for patients with intermediate maxillary RBH (4 to 8 mm). Furthermore, the results of this study show that LSFE for patients with intermediate RBH is not a suitable treatment option because of unjustified high cost and rate of complications.

What surgical approach has the lowest risk of the lower lid complications in the treatment of orbital floor and periorbital fractures? A frequentist network meta-analysis.

PURPOSE: Evidence on the best surgical approach with the lowest lower lid complications (LLCs) in the treatment of orbital floor (OF) and periorbital fractures (POFs) is limited because of the absence of head-to-head studies. We performed this network meta-analysis (NMA) to compare various surgical approaches in treatment of OFs and POFs, with respect to LLCs. MATERIALS AND METHODS: This NMA based on PRIMSA guidelines studied the incidence of the LLCs among various surgical approaches in the treatment of the OFs and POFs. We searched several databases from 1970 to March 2018. All clinical studies comparing different surgical approaches in treatment of OFs and POFs were included. Outcome variables were ectropion, entropion, scleral show and other complications. Predictor variables were transconjunctival approach (TCA), subciliary approach (SCA), subtarsal approach (STA) and infraorbital approach (IOA). Frequentist NMA was performed using STATA software. RESULTS: A total of 47 studies with 5267 cases of the OFs and POFs received ORIF using 4 surgical approaches with 6 comparisons were included. TCA significantly reduces the prevalence of ectropion than SCA (OR = 3.54, CI1.28-9.84), but no significant difference was found between TCA and, STA or TCA and IOA. SCA and STA significantly reduce the prevalence of entropion than TCA (OR = 5.02, CI, 1.79-14.06, OR = 0.11, CI, 0.02-0.57) respectively. We found no significant difference between the 6 comparisons with respect to other complications. CONCLUSION: This NMA shows that the application of various surgical approaches leads to different incidences of LLCs. While TCA appears to have the lowest overall LLCs rate, STA has lowest rate among the transcutaneous approaches. The choice of an appropriate surgical approach for a given fracture should take these among other factors into consideration. Owing to the limitations of this study, we suggest that the results be interpreted with caution.

Does intraoperative perforation of Schneiderian membrane during sinus lift surgery causes an increased the risk of implants failure?: A systematic review and meta regression analysis.

PURPOSE: There is still debate whether intraoperative Schneiderian membrane (SM) perforation in the maxillary sinus lift causes an increase the risk of implants failure. The aim of this study was to assess an association between SM perforation and implants loss following the maxillary sinus lift. MATERIALS AND METHODS: A systematic review and meta-analysis of clinical studies assessing association between SM perforation and implants failure based on PRISMA was conducted. Three major databases were used to gather research dating from their respective inception up until March 2018. All clinical studies expressly reported the number of the SM perforation and implants loss that installed in the perforated and nonperforated sinuses were included. The statistical analyses used were Pearson's correlation, simple linear regression, and meta regression. The risk ratio (RR) of implant loss between perforated and nonperforated sites was estimated. RESULTS: A total of 2947 patients with 3884 maxillary sinuses augmentations who received 7358 implants, enrolled in 58 studies were included in this study. There was a significant relationship between the implants' failure and SM perforation according to simple linear regression (P < .001) and meta regression analysis (P = .06). There was a significant decrease (moderate quality evidence) in implant loss in the nonperforated sinuses compared to perforated sunrises (RR = 2.17, CI: 1.52-3.10, P = .001). There was also no significant association between implant loss in the perforated sinuses and the surgical devices used (piezosurgical or rotary), surgical approach applied (lateral or crestal sinus lift), barrier membrane used and type of bone grafting materials. CONCLUSION: The results of this study showed that an intraoperative SM perforation could increase the risk of implant failure after the sinus lift surgery.

Accuracy of Virtual Surgical Planning in Treatment of Temporomandibular Joint Ankylosis Using Distraction Osteogenesis: Comparison of Planned and Actual Results.

PURPOSE: This study evaluated the accuracy of virtual surgical planning and 3-dimensional (3D) printed templates to guide osteotomy and distraction osteogenesis (DO) in the treatment of temporomandibular joint (TMJ) ankylosis and secondary mandibular deformity. PATIENTS AND METHODS: Seven consecutive patients diagnosed with TMJ ankylosis and mandibular deformities were included. A composite skull model was obtained with data from spiral computed tomography (CT) and laser scanning of the dental arch. A virtual surgical simulation was performed using Dolphin Imaging 11.7 Premium (Dolphin Imaging and Management Solutions, Chatsworth, CA). Then, the virtual plan was transferred to the operation using 2 surgical templates. These templates were designed by 3D printing using data from the virtual surgical simulation for guiding the osteotomy and the DO, respectively. The preoperative measurement and differences between the actual mandibular position and the virtual plan were analyzed. RESULTS: Postoperative radiographs, CT images, and quantitative analysis showed a clinically acceptable precision for the position of the mandible. The mean length of the mandible and the vertical height of the DO were 79.1 and 14.9 mm, respectively. With the 3D superimposition and linear measurement, the mean difference between the virtual plan and the actual results ranged from 0.64 ± 0.20 to 1.90 ± 0.85 mm. All patients obtained satisfactory changes in the facial profile and marked improvement in postoperative pharyngeal airway space and mouth opening. CONCLUSION: The results of this study showed that virtual surgical planning and 3D printed guiding templates facilitated treatment planning, an accurate osteotomy, repositioning of bony segments, and contouring of the mandibular border in the treatment of TMJ ankylosis and secondary mandibular deformity.