Does the Addition of Oral Sampling Improve Waveform Capnography When Compared to Traditional Nasal Sampling in Open-Airway Patients?

BACKGROUND: End-tidal carbon dioxide (EtCO2) is an invaluable anesthesia measure due to minimal delay in monitoring ventilation. Oral and Maxillofacial Surgery (OMS) presents special challenges because oral exhalations are not sampled effectively via nasal cannula normally used to avoid interfering with procedures. PURPOSE: The purpose of the study was to compare EtCO2 waveforms obtained in subjects using nasal monitoring and combined nasal and oral monitoring under simulated ventilatory conditions. STUDY DESIGN, SETTING, SAMPLE: A single-blinded, randomized crossover controlled study was conducted at the University of Illinois Chicago with healthy volunteers, who were blinded to the monitoring system used. Inclusion criteria required subjects be ≥ 18 years of age, be consentable, and English-speaking. Exclusion criteria required no airway abnormalities, no edentulism, and no conditions that preclude undergoing an OMS procedure under sedation. PREDICTOR VARIABLE: The primary predictor variable was the EtCO2 monitoring system: nasal with a standard nasal cannula, and combined with a nasal cannula and oral device. The secondary predictor variable evaluated 3 ventilatory states (nasal breathing, oral breathing, and apnea) in each arm, standardizing by maintaining consistent breath counts across observation periods. MAIN OUTCOME VARIABLE: The main outcome variable was the number of waveforms recorded over 30 seconds for nasal and combined monitoring. Each recording was standardized by dividing it by the baseline waveforms and multiplying by 20. Higher values, closer to baseline, were considered more accurate depictions of ventilation. COVARIATES: Covariates were body mass index (BMI), age, sex, Mallampati score, and breathing method. ANALYSES: Analysis of variance, analysis of covariance, and multivariate analysis of variance were performed. P value < .05 was considered statistically significant. RESULTS: The sample included 25 subjects (18 male and 7 female) with mean age 29.9 ± 7.98 years and BMI 23.9 ± 3.51 kg/m2. Combined sampling detected more waveforms during nasal and oral breathing (P < .001). Higher BMI correlated with reduced waveform capture during nasal sampling in oral breathing (P = .013). Combined sampling detected more waveforms during nasal breathing (P = .005) in subjects with BMI < 23.5 kg/m2. Mallampati score correlated with increased waveforms during nasal breathing. CONCLUSION AND RELEVANCE: Oral EtCO2 sampling may improve accuracy of capnography waveform capture. Further clinical studies in sedated subjects undergoing OMS procedures are needed.

Does Maxillomandibular Fixation Technique Affect Occlusion Quality in Segmental LeFort I Osteotomy?

BACKGROUND: Segmental maxillary osteotomies require precise occlusal control due to variability in individual segment positioning. The role of maxillomandibular fixation (MMF) technique on occlusal control has not been validated. PURPOSE: The purpose is to measure and compare the accuracy of occlusal positioning among MMF techniques. STUDY DESIGN, SETTING, SAMPLE: This was a double-blinded in vitro study on experiment models to simulate a 3-piece LeFort I osteotomy. The models were constricted posteriorly and expanded using 3 different MMF techniques and compared to the unaltered baseline occlusion. Based on sample size calculation, 32 separate attempts were made for each MMF technique. PREDICTOR VARIABLE: The predictor variable was MMF technique (brackets, MMF screws, and embrasure wires). MAIN OUTCOME VARIABLES: The primary outcome variable was the visual occlusal analysis score, a 1.00 to 4.00 continuous scale measuring the similarity of the achieved occlusion to the planned (control) occlusion assessed by an oral and maxillofacial surgeon and an orthodontist. High visual occlusal analysis score indicated greater occlusal accuracy, with 3.50 defined as the threshold for accuracy. The secondary outcome variable was the linear error of the achieved occlusion at the canine and first molar teeth, with lower error indicating greater accuracy. An a priori accuracy threshold of 0.5 mm was set for this variable. COVARIATES: None. ANALYSES: Kruskal-Wallis test with post hoc testing was used to analyze the difference in the outcome variables of interest. P value < .05 was considered statistically significant. RESULTS: Thirty-two attempts for each technique showed that brackets had higher VAOS than MMF screws and embrasure wires (median differences 1.49 and 0.48, P < .001), and had lower linear occlusal error (median differences 0.35 to 0.99 mm, P < .001). CONCLUSION AND RELEVANCE: MMF technique influences the quality of occlusal control, with greater visual rating scores and lower linear errors seen with brackets than with embrasure wires or MMF screws.

Are There Differences in the Causes and Complications of Mandibular Third Molar Extraction in Older Patients Compared to Younger Patients?

BACKGROUND: Although most impacted third molars (ITMs) are extracted in the teens and early 20s, some undergo extractions after their 40s. It is unclear whether the reasons for extraction, the degree of impaction, and complications differ in patients in an older age group compared with a younger age group. PURPOSE: The purpose of this study was to measure the association between age and 1) reason for extraction and 2) postoperative complications. STUDY DESIGN, SETTING, SAMPLE: This was a retrospective cohort study of patients who had undergone surgical extraction of at least one mandibular ITM at a single institution. We excluded 1) age under 20 years, 2) follow-up period of less than 1 week, and 3) tooth extraction under general anesthesia. PREDICTOR VARIABLE: The primary predictor variable was age, classified into 3 groups (20s:20-29; 30s:30-39; over 40s: 40 and greater). MAIN OUTCOME VARIABLE(S): The primary outcome variables were the reason for extraction (prophylactic or symptomatic) and the presence of complications. The secondary outcome variable was type of complication (postoperative infection, dry socket, neurosensory disturbance, presenting pain over 1 month, retained root requiring secondary treatment). COVARIATES: The covariates were sex, laterality of ITM, and difficulty of extraction as measured by the difficulty index, a measure based on depth, orientation, and ramus relationship/space available, with a higher score indicating greater difficulty. ANALYSES: χ2 test was performed to analyze the association of categorical outcome variables and covariates. Level of statistical significance was set at P < .05. RESULTS: Of a total of 831 eligible subjects, there were 555 (66.8%), 159 (19.1%), and 117 (14.1%) in the 20s, 30s, and over 40s age groups, respectively. The percentage of symptomatic extraction of ITM was significantly higher in the over-40 age group compared with the 20s group (92.3 vs 69.4%, (P < .001). Complication rate also significantly differed between over 40s group and the 20s group (7.7 vs 1.8%, P < .001). Difficulty index and indications for ITM extraction were significantly different between groups (P < .001). CONCLUSION AND RELEVANCE: Symptoms, difficulty, and complications related to ITM increase at over 40 years of age. This should be taken into consideration during the joint clinical decision-making process with patients with ITM.

Predicting the Future Focus of Orthognathic Surgery: Outcome-Driven Planning and Treatment With Function, Esthetics, and Occlusion as Key Indicators.

As an international group of orthognathic surgeons, we believe the next big thing in orthognathic surgery will be a clinical and research focus on patient-oriented outcomes and improved quality of life. We expect to see advances in diagnosis and treatment planning, materials development, and patient management.

Which Factors Affect the Reduction Quality of Open Reduction Internal Fixation of Mandibular Subcondylar Fractures?

BACKGROUND: Open reduction internal fixation (ORIF) of mandibular subcondylar fractures (MSF) involves several variables that could affect decision making. There is insufficient data regarding factors influencing the outcomes of MSF ORIF. PURPOSE: The purpose of this study was to investigate factors associated with quality of bony reduction of MSF and occlusion, after ORIF. STUDY DESIGN, SETTING, AND SAMPLE: We designed a retrospective cohort study of consecutively treated subjects for MSF ORIF, ages 18 to 64 years, by University of Illinois' Department of Oral and Maxillofacial Surgery, between January 1, 2013, and January 26, 2021. PREDICTOR VARIABLE: The primary predictor variable was the vertical level of MSF from the gonial angle. Secondary predictor variables included surgeon, fixation scheme (number and configuration of miniplate), surgical approach, time to surgery, mechanism of injury, vertical fragment overlap, overlying soft tissue thickness, presence of other mandibular fractures, and severity and direction of displacement. MAIN OUTCOME VARIABLES: The primary outcome variable was the mean radiographic reduction score (RRS), rated by 2 blinded observers on a 1 to 5 scale. The secondary outcome variable was presence of postoperative malocclusion as documented in the medical records. COVARIATES: Covariates were age and sex. ANALYSES: Descriptive statistics were computed. To investigate the influence of the predictor variables on reduction quality, multifactorial analysis of variance with post hoc Tukey test was performed. For malocclusion, χ2 test was performed. The level of significance was set at P < .05. RESULTS: Thirty-eight MSF in 37 subjects were included. Mean age was 32.7 years (range 18 to 64), and 83.8% were male. Mean RRS was 4.38 (standard deviation 0.77). Fixation scheme was the only variable that showed significant impact on RRS: single-straight miniplate had lower scores than double-straight (-1.50, P = .011), rhomboid (-1.29, P = .036), and ladder miniplates (-1.38, P = .048). There was 1 incidence of malocclusion (2.7%) which resolved without intervention. CONCLUSIONS AND RELEVANCE: Favorable reduction (anatomic reduction to mild discrepancies) can be achieved without malocclusion using double-straight, or rhomboid-shaped or ladder-shaped miniplates, without influences from patient or injury-related factors. In contrast, single-straight miniplate fixation resulted in moderate discrepancies in reduction, although it did not lead to malocclusion.

What Is the Linear Accuracy of Regional Voxel-Based Registration for Orthognathic Surgery Landmarks?

PURPOSE: While regional voxel-based registration (R-VBR) has been shown to have excellent reproducibility and angular accuracy, there are limited data on the linear accuracy of R-VBR for common orthognathic surgery landmarks, or on whether angular accuracy correlates with linear accuracy. The purpose of this study was to estimate the linear accuracy of R-VBR for several skeletal landmarks commonly used in orthognathic surgical planning, and to measure the correlation between angular and linear discrepancies. MATERIALS AND METHODS: This is a retrospective cross-sectional study of consecutive patients treated at a single center with nonsegmental LeFort I and bilateral sagittal split osteotomy surgery from January 2019 to November 2020. Cone beam computed tomography at the preoperative (T0) and immediate postoperative (T1) stages were analyzed to measure the postoperative positional changes of 11 orthognathic landmarks in 4 regions of interest (ROI) using R-VBR performed twice by two examiners. Pairwise correlation analysis and canonical correlation analysis were performed for the angular discrepancies (primary predictor variable) and the linear discrepancies (primary outcome variable) to measure the correlation between the two. RESULTS: In cone beam computed tomography analysis of 28 eligible subjects (16 males, 12 females; mean age 18.9 years, range 15 to 25), the mean absolute (MA) angular discrepancies ranged from 0.15° to 0.55°, while the corresponding MA linear discrepancies ranged from 0.05 to 0.41 mm. There was a strong correlation between angular and linear discrepancies that was statistically significant (P = .001 to .04, Spearman's rank correlation coefficient 0.38 to 0.87). CONCLUSIONS: For nonsegmental LeFort I osteotomies and bilateral sagittal split osteotomy, R-VBR has excellent linear accuracy within a single voxel size (0.3 mm) for commonly used orthognathic landmarks in the maxillary and distal mandibular ROI. The MA linear discrepancy for the proximal mandibular segment ROI was greater than a single voxel size, with a maximum of 0.41 mm.

Reconstruction of Large Full-Thickness Lower Eyelid Defects With Remnant Eyelid Rotation, Semicircular Skin and Muscle Flap, and Lateral Tarsoconjunctival Flap.

PURPOSE: To describe and assess the results of reconstruction of large, full-thickness defects of the central or medial lower eyelid using a semicircular skin flap, rotation of the remnant lateral eyelid, and a lateral tarsoconjunctival flap. METHODS: The surgical approach is described, and the authors performed a retrospective chart review of consecutive patients between 2017 and 2023 reconstructed with this technique. Outcomes were assessed for size of eyelid defect, vision, subjective symptoms, facial and palpebral aperture symmetry, eyelid position and closure, corneal examination, surgical complications, and need for subsequent surgical intervention. Postoperative appearance was graded on malposition, distortion, asymmetry, contour deformity, and scarring (MDACS). RESULTS: Charts of 45 patients were identified. The average size of the lower eyelid defect was 18 mm (ranging from 12 to 26 mm). Facial and palpebral aperture symmetry were acceptable and all patients had preserved visual acuity and eyelid position and closure. The MDACS cosmetic score was perfect (0) in 15.6% (7/45) of eyelids, good (1-4) in 80.0% (36/45) of eyelids, and mediocre (5-14) in 4.4% (2/45) of eyelids. Second stage reconstruction was not necessary in 32 (71.1%) cases. There were no serious surgical complications, but minor complications included redness of the eyelid margin and pyogenic granulomas. CONCLUSIONS: Medial rotation of the remnant lower eyelid with a lateral semicircular skin and muscle flap over a lateral tarsoconjunctival flap was very effective in this series. Benefits include scarring within the facial skin tension lines, maintained vision throughout the recovery period, no eyelid retraction, and often single stage reconstruction.

Metastatic Epithelioid Sarcoma of the Eyelid in a 47-Year-Old Man: A Case Report.

Epithelioid sarcoma is a rare soft tissue neoplasm of uncertain differentiation that typically affects the distal extremities. Primary orbital epithelioid sarcoma is rare, and no reports exist characterizing metastases of this tumor to the orbit and ocular adnexa. In this article, the authors describe a rare case of eyelid metastasis in a 47-year-old man with epithelioid sarcoma of the right fibula diagnosed 16 months earlier who was otherwise doing well on the adjuvant tazemetostat therapy. In addition, the authors perform a retrospective review of cases of primary orbital epithelioid sarcoma reported in the literature, of which 4 patients responded favorably to surgical excision whereas 2 others eventually died as a direct result of their disease.

Kimura Disease of the Periorbita and Earlobe in a 15-Year-Old Male: A Case Report and Review of the Literature.

PURPOSE: The authors describe a case of Kimura disease (KD) affecting the lacrimal gland, the ipsilateral periorbita, and the contralateral earlobe. The authors also review the literature for characteristics and outcomes of KD affecting the periorbita or earlobe. METHODS: The authors review retrospectively a single chart and abstract data from the English language literature. RESULTS: A 15-year-old Samoan male presented with a left upper eyelid mass and later the contralateral earlobe and ipsilateral periorbita. Surgical resection was partially effective and normal vision and eye motility were maintained. Histopathology was consistent with KD. Thirty-seven cases of periorbital KD were identified in the literature. The average age of patients with periorbital KD was 31.9 years (standard deviation: 17.8 years), with 81.1% (30/37) of patients being male and 69.4% (25/36) Asian. Over half of periorbital KD patients had lacrimal gland involvement (51.3%; 19/37). Fifteen patients were initially treated with surgery; 3 (20%) had recurrence of the disease. Another 15 patients were initially treated with corticosteroids; 12 (80%) had recurrence of the disease. Ophthalmologic data, when reported, demonstrated that, most patients had no visual (77.8%; 14/18 patients) or motility disturbances (82.4%; 14/17 patients) but most had proptosis 71.4% (10/14). Only 4 cases of earlobe involvement in KD were identified, all in women. CONCLUSIONS: In the literature, orbital KD was rare but often affected the lacrimal gland and caused proptosis, commonly in young adult Asian males. Vision and extraocular motility were usually normal. Earlobe involvement was very rare. This unique case of KD that affected the orbit and contralateral earlobe corroborates the prior literature that KD is prone to recurrence but may not adversely affect vision or extraocular motility.

The role of muscular traction in the occurrence of skeletal relapse after advancement bilateral sagittal split osteotomy (BSSO): A systematic review.

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

Do We Need Safety Nets for Outsourced Computer-Aided Orthognathic Planning? A Two-Center Analysis.

PURPOSE: While the accuracy, cost-effectiveness, and time-efficiency of computer-aided orthognathic surgical planning (CAOP) have been studied, little is known about the influence of logistical factors of outsourced CAOP (OS-CAOP) on patient care. The purpose of this study was to investigate the limitations of OS-CAOP and their effect on treatment planning workflow and surgical outcomes. METHODS: A retrospective cross-sectional study was designed involving subjects who had undergone orthognathic surgery using CAOP from 2 academic oral and maxillofacial surgery centers in South Korea (Kyungpook National University, KNU) and the United States (University of Illinois Chicago, UIC) over an 8-year period. The primary predictor variable was use of modifications or alternatives to OS-CAOP. The primary outcome variable was the frequency of planning changes due to reasons that may have affected outcomes. Covariates included age and sex. Descriptive statistics was used, in addition to a chi-square test to analyze differences among categorical variables. RESULTS: Of a total of 642 eligible subjects in both centers, 5.8% used alternatives to OS-CAOP. 78.4% of these were due to reasons that may have affected outcomes (P < .001), representing 4.5% of all cases. The frequency of the need for OS-CAOP alternatives was identical in both centers (5.8%), but the specific reasons varied, with KNU having mostly plan-related changes (38.1% of alternatives), and UIC with more access and education-related reasons (68.8% of alternatives). At KNU, 71.4% of all alternatives were by repeat OS-CAOP, whereas at UIC, all were by in-house CAOP (IH-CAOP). CONCLUSIONS: In 2 major academic oral and maxillofacial surgery centers in South Korea and the United States, a substantial portion of OS-CAOP required pre-surgical modification, or use of alternatives. Most of the changes were for reasons that could potentially impact outcomes, prompting the need to consider establishing a "safety net" plan compatible with individual clinician's practice setting and healthcare system.

What Is the Perception of an Esthetic Lower Facial Third Profile in the Korean Layperson Population?

PURPOSE: The purpose of this study is to investigate whether there were differences in perception of facial profile esthetics at the upper lip, gnathic, and genial levels according to observer gender and age in the Korean layperson population. METHODS: Ten male (M1 to M10) and 10 female (F1 to F10) silhouettes with differing facial profiles at the level of the upper lip, mandibular, and chin were created from a male and female facial profile deemed well-balanced and orthognathic by reviewer consensus. These silhouettes were presented to 288 participants who were asked to rank the 5 most attractive male and female profiles. The participants were composed of 144 males and 144 females divided into 4 age groups: group I (under 20 years), group II (20 to 39 years), group III (40 to 59 years), and group IV (over 60 years). The most preferred profile and observer scores were investigated and calculated. Descriptive analysis, χ2 test, and analysis of variance were used for statistical analysis according to age and gender. RESULTS: The most preferred male and female silhouettes were orthognathic profiles. There was no significant difference according to gender when rating male (P = .281) and female (P = .442) silhouettes. No statistically significant difference was observed even when analyzed according to age groups. Although the difference in observer scores among each ranking showed a statistical difference according to age groups, the overall rankings showed a similar pattern both in male and female silhouettes. In the same age group, no difference in rank scores according to gender was observed. Severe concave profiles were found to have the lowest rank. CONCLUSIONS: An orthognathic profile was rated as the most desirable in the Korean layperson population, with few differences in perception of esthetic facial profile according to age and gender.

What Do We Know Beyond Reliability in Voxel-Based Registration? Validation of the Accuracy of Regional Voxel-Based Registration (R-VBR) Techniques for Orthognathic Surgery Analysis.

PURPOSE: Despite having excellent reproducibility, the accuracy of regional voxel-based registration (R-VBR) techniques used for postoperative orthognathic surgical analysis has not been validated. The purpose of this study was to validate the accuracy of R-VBR. METHODS: Preoperative (T0) and postoperative (T1) cone beam computed tomography (CBCT) of consecutive patients treated at a single center with nonsegmental LeFort I and bilateral sagittal split osteotomy were included. T1 CBCTs were oriented to match that of the standardized T0, and thus were assigned a known rotational transformation matrix in pitch/roll/yaw (P/R/Y), to create T1-prime (T1'). A copy of T1 (cT1) was made and was superimposed to T1' using R-VBR for 4 regions of interest (ROI): maxilla, distal mandible, right proximal mandible, and left proximal mandible, to create cT1'. The transformation matrix for each of the ROI was compared to those of T1' using paired t test and Bland-Altman analysis. RESULTS: Twenty-eight eligible subjects' CBCTs were analyzed. Mean difference between T1' and cT1' ranged from -0.08 to 0.14° (maximum 0.73°), with no statistically significant differences (P = 0.216 to 1). Mean absolute difference ranged from 0.13 to 0.31° (maximum 0.73°). Bland-Altman analysis showed good agreement between T1' and cT1', indicating excellent accuracy. CONCLUSIONS: R-VBR using the maxilla, distal mandible, and the bilateral proximal mandibular segments as ROI has excellent accuracy in terms of rotational measurements.

Mechanical Loading Disrupts Focal Adhesion Kinase Activation in Mandibular Fibrochondrocytes During Murine Temporomandibular Joint Osteoarthritis.

PURPOSE: Mechanical overloading is a key initiating condition for temporomandibular joint (TMJ) osteoarthritis (OA). The integrin-focal adhesion kinase (FAK) signaling axis is implicated in the mechanobiological response of cells through phosphorylation at Tyr397 (pFAK) but poorly defined in TMJ health and disease. We hypothesize that mechanical overloading disrupts TMJ homeostasis through dysregulation of FAK signaling. MATERIALS AND METHODS: To assess if FAK and pFAK are viable clinical targets for TMJ OA, peri-articular tissues were collected from patients with TMJ OA receiving a total TMJ replacement. To compare clinical samples with preclinical in vivo studies of TMJ OA, the joints of c57/bl6 mice were surgically destabilized and treated with and without inhibitor of pFAK (iFAK). FAK signaling and TMJ OA progression was evaluated and compared using RT-PCR, western blot, immunohistochemistry, and histomorphometry. To evaluate mechanical overloading in vitro, primary murine mandibular fibrochondrocytes were seeded in a 4% agarose-collagen scaffold and loaded in a compression bioreactor with and without iFAK. RESULTS: FAK/pFAK was mostly absent from the articular cartilage layer in the clinical sample and suppressed on the central condyle and elevated on the lateral and medial condyle in murine TMJ OA. In vitro, compressive loading lowered FAK/pFAK levels and elevated the expression of TGFß, NG2, and MMP-13. iFAK treatment suppressed MMP13 and Col6 and elevated TGFß, NG2, and ACAN in a load independent manner. In vivo, iFAK treatment moderately attenuated OA progression and increased collagen maturation. CONCLUSION: These data illustrate that FAK/pFAK is implicated in the signaled dysfunction of excessive mechanical loading during TMJ OA and that iFAK treatment can moderately attenuate the progression of cartilage degeneration in the mandibular condyle.

Three-dimensional assessment of the anterior and inferior loop of the inferior alveolar nerve using computed tomography images in patients with and without mandibular asymmetry.

BACKGROUND: The purpose of this study was to investigate the differences in configuration and dimensions of the anterior loop of the inferior alveolar nerve (ALIAN) in patients with and without mandibular asymmetry. METHOD: Preoperative computed tomography images of patients who had undergone orthognathic surgery from January 2016 to December 2018 at a single institution were analyzed. Subjects were classified into two groups as "Asymmetry group" and "Symmetry group". The distance from the most anterior and most inferior points of the ALIAN (IANant and IANinf) to the vertical and horizontal reference planes were measured (dAnt and dInf). The distance from IANant and IANinf to the mental foramen were also calculated (dAnt_MF and dInf_MF). The length of the mandibular body and symphysis area were measured. All measurements were analyzed using 3D analysis software. RESULTS: There were 57 total eligible subjects. In the Asymmetry group, dAnt and dAnt_MF on the non-deviated side were significantly longer than the deviated side (p < 0.001). dInf_MF on the non-deviated side was also significantly longer than the deviated side (p = 0.001). Mandibular body length was significantly longer on the non-deviated side (p < 0.001). There was no significant difference in length in the symphysis area (p = 0.623). In the Symmetry group, there was no difference between the left and right sides for all variables. CONCLUSION: In asymmetric patients, there is a difference tendency in the ALIAN between the deviated and non-deviated sides. In patients with mandibular asymmetry, this should be considered during surgery in the anterior mandible.

"Monoblock" Occlusal Model to Enhance Occlusal Verification During Orthognathic Surgery.

Intraoperative verification of the planned occlusion is critical in ensuring the accuracy of orthognathic surgery. This step is limited to visual inspection, which can be especially challenging when the planned occlusal setup is less-than-stable. The authors introduce a cost-effective method of an accurate reproduction of the planned occlusion using additive manufacturing which can aid in intraoperative verification of positionally unstable occlusal setups. The authors present a case example, and discuss various technical considerations.

Three-Dimensional Analysis of Lip Asymmetry and Occlusal Cant Change After Two-Jaw Surgery.

PURPOSE: Lip asymmetry greatly influences patient satisfaction after 2-jaw surgery. The purpose of the present study was to identify the influence of skeletal changes on lip cant correction in 2-jaw surgery for mandibular prognathism with asymmetry. MATERIAL AND METHODS: The present retrospective cohort study included consecutive skeletal Class III patients who had undergone Le Fort I and sagittal split ramus osteotomy with preoperative and 6-month postoperative cone-beam tomography scans available. The primary predictor variables were the postoperative hard tissue changes (canine cant, first molar cant, transverse change at menton [Me] after surgery, and changes postoperatively from preoperatively). The primary outcome variable was the change in the soft tissue lip cant. The secondary outcome variables were the changes in various landmarks representing perioral asymmetry, including center of cupid's bow, lower lip vermilion, and subnasale. Other variables included subject age and gender. Descriptive statistics and regression and correlation analyses were used to investigate the important predictors influencing lip cant change. RESULTS: A total of 58 patients (33 males; average age, 21.7 years) were included in the present study. The demographic variables of the asymmetry group (Me deviation >4 mm) were not different from those of the control group. Postoperative changes in Me deviation correlated significantly with the changes in the transverse position of the subnasale, upper lip, and horizontal and vertical differences in the mouth corner position (P < .01 for all) but not with the maxillary occlusal cant change. Linear regression analysis showed lip cant correction was associated with changes in Me deviation (P < .001) and molar cant change (P = .032), but not with canine cant change. CONCLUSIONS: Maxillary occlusal cant correction itself cannot fully account for changes in lip cant. The transverse Me change-rather than maxillary cant correction-had the greatest influence on lip cant. These results suggest that correction of chin deviation must be addressed in lip cant correction for facial asymmetry.

How Accurate Is 3-Dimensional Computer-Assisted Planning for Segmental Maxillary Surgery?

PURPOSE: The 3-dimensional (3D) accuracy of computer-assisted planning (CAP) of segmental maxillary osteotomies has seldom been reported with a comprehensive 3D analysis. The aim of the present study was to measure the accuracy of computer-planned segmental maxillary surgery and to identify the factors associated with accuracy. MATERIALS AND METHODS: The present retrospective, cross-sectional study investigated cone-beam computed tomography (CBCT) scans of patients who had undergone segmental maxillary osteotomy with CAP at a single center from January 2013 to October 2019. The predictor variables were age, gender, diagnosis, CAP method, type of maxillary segmentalization, surgeon, surgical sequence, and magnitude of planned and actual movements. The primary outcome variable was surgical discrepancy (linear differences between the actual and planned maxillary movements using CAP in the x, y, and z coordinates) at various 3D landmarks. The mean difference and absolute mean difference (AMD) were computed to estimate the direction and magnitude of the discrepancies. In addition, a 2.0-mm threshold of surgical discrepancy was used to determine clinically acceptable accuracy. The association between the predictor and outcome variables were analyzed statistically using correlation and regression analyses. RESULTS: The sample included 63 patients (mean age, 20.1 years; 42.9% male). The surgical discrepancy was similar for 2- and 3-piece segmental maxillary osteotomies. Overall, the AMD for all patients was 0.96 ± 0.69 mm transversely, 1.23 ± 0.83 mm vertically, and 1.16 ± 0.80 mm anteroposteriorly (P < .01 for all). The discrepancy between the actual and planned movements was within 2.0 mm for more than 80% of cases. The major predictor variable that affected surgical discrepancy was the magnitude of the actual surgical movements (P < .01). CONCLUSIONS: 3D CAP showed clinically acceptable accuracy for segmental maxillary osteotomies comparable to that of nonsegmental cases. Although the magnitude of actual surgical movements was shown to affect surgical accuracy, the sources of surgical discrepancies requires further investigation.

Ankyloglossia Superior Associated With Moebius Syndrome: A Case Report.

Ankyloglossia superior is an exceedingly rare congenital condition that consists of a connection between the tongue and hard palate. This abnormality is considered part of the ankyloglossia superior syndrome when found with other malformations such as limb deformities, gastrointestinal malformation, and cleft palate. Ankyloglossia superior can also be associated with other known syndromes. We have presented the case of a female infant born with multiple malformations, including partial agenesis of the feet and hands, micrognathia, a lack of expression of the facial muscles, convergent strabismus, mouth opening limitation, and tongue-palate adhesion. The patient's presenting diagnosis was ankyloglossia superior associated with Moebius syndrome. Computed tomography revealed the extent of the ankyloglossia superior and the loss of integrity of the palatal shelf. Surgical release of the ankyloglossia superior was performed with the patient under general anesthesia. Multiple management challenges were encountered postoperatively. To the best of our knowledge, ankyloglossia superior presenting in conjunction with Moebius syndrome had not been formally described in a case report.