Assessment of Masseter Volume and Postoperative Stability After Orthognathic Surgery in Patients With Skeletal Class III Malocclusion With Facial Asymmetry.

OBJECTIVE: This study aimed to evaluate the effect of orthognathic surgery on masseter volume in patients with skeletal Class III malocclusion with facial asymmetry and the effect of masseter volume on stability in orthognathic surgery. METHODS: This research studied 16 patients with Class III malocclusion with facial asymmetry who received combined orthodontic-orthognathic treatment and underwent craniofacial computed tomography (CT) before (T0), 2 weeks after (T1), and 6 months after (T2) surgery. Three-dimensional (3D) CT images were retrospectively analyzed, using 3D volume reconstruction to obtain the masseter volume and examine the impact of the masseter volume on stability in orthognathic surgery. RESULTS: A statistically significant difference ( P < 0.05) in the volume of the masseter was found up to 6 months after orthognathic surgery compared with the preoperative period, and the reduction in the masticatory muscle volume on the lengthened side is greater than on the shortened side ( P < 0.05). The volume of both masseters differed according to facial asymmetry, and the difference was significantly reduced after orthognathic surgery ( P < 0.05). During the period time (T1-T2), cephalometric maxillary marker points were not significantly different ( P > 0.05), and mandibular marker points were significantly anteriorly shifted ( P < 0.05). There was an association between the masseter volume and anterior shift of point B (R > 0.5, P < 0.05), the upward and anterior shifts of the gonion point differed between the lengthened and shortened sides ( P < 0.05). CONCLUSION: The size of the masseter becomes smaller 6 months after orthognathic surgery, and orthognathic surgery improves both bone and soft tissue symmetry. A larger sagittal relapse of mandibular setback occurred in patients with greater masseter volume. Considering these alterations may be helpful in planning orthognathic surgery.

Assessment of cephalometric parameters and correlation with the severity of the obstructive sleep apnea syndrome.

BACKGROUND: In individuals diagnosed with obstructive sleep apnea syndrome (OSAS), variations in craniofacial structure have been inconsistently documented, showing differing degrees of alteration between obese and nonobese patients. In addition, sleep disturbance has also been shown to induce disequilibrium in this population of patients. This pilot observational study aimed to assess craniofacial values in obese and nonobese subpopulations of patients with OSAS and their correlation and association with the severity of OSAS. We also assessed whether OSAS patients are characterized by an impaired equilibrium in relation to and associated with the severity of OSAS. METHODS: We included all consecutive adult patients with OSAS. Through cephalometry, we assessed the upper (UPa-UPp) and lower (LPa-LPp) pharynx diameters, superior anterior facial height (Sor-ANS), anterior facial height (ANS-Me), anterior vertical dimension (Sor-Me), posterior facial height (S-Go) and craniovertebral angle (CVA). Furthermore, we analyzed postural equilibrium through a stabilometric examination. RESULTS: Forty consecutive OSAS patients (45% female with a mean age of 56 ± 8.2 years) were included. The subgroup of nonobese patients had a reduced UPa-UPp (p = 0.02). Cephalometric measurements were correlated with the severity of OSAS in nonobese patients, whereas only Sor-ANS was correlated with the severity of OSAS in the obese subpopulation. In the overall population, altered craniofacial values are associated with severe OSAS. Although there are differences in equilibrium between obese and nonobese OSAS patients, the stabilometric measurements were not correlated or associated with OSAS severity. CONCLUSION: Altered craniofacial values and compromised equilibrium in OSAS patients are linked to OSAS severity. Therefore, the management of OSAS should be tailored not only to weight management but also to craniofacial and postural rehabilitation to enhance patient outcomes.

Establishment of the mid-sagittal reference plane for three-dimensional assessment of facial asymmetry: a systematic review : Establishment of the mid-sagittal reference plane: a systematic review.

OBJECTIVE: To systematically review the literature for mid-sagittal plane establishment approaches to identify the most effective method for constructing the mid-sagittal plane for the evaluation of facial asymmetry. MATERIALS AND METHODS: Six electronic databases (PubMed, Medline (via Ovid), EMBASE (via Ovid), Cochrane Library, Web of Science, and Scopus) and grey literature were searched for the studies that computed the mid-sagittal reference plane three-dimensionally, using a combination of MeSH terms and keywords. The methodological quality and the level of evidence for the included studies were analyzed using QUADAS-2 and GRADE, respectively. RESULTS: The preliminary search yielded 6746 records, of which 42 articles that met the predefined inclusion criteria were included in the final analysis. All the included articles reported the construction of the mid-sagittal reference plane (MSP) using varied methods. The risk of bias and concerns regarding the applicability of the included studies were judged to be 'low'. The level of evidence was determined to be 'low' for the effectiveness of the technique and 'moderate' for the ease of clinical applicability. CONCLUSION: Despite methodological heterogeneity, this review substantiates the comparable efficacy of cephalometric and morphometric MSP construction methods. A fully automated morphometric MSP holds promise as a viable option for routine clinical use. Nevertheless, future prospective studies with an emphasis on the impact, accuracy, and clinical applicability of MSP construction techniques in cases of facial asymmetry are required. CLINICAL RELEVANCE: The present review will assist clinicians in selecting the most suitable method for MSP construction, leading to improved treatment planning and ultimately more favorable treatment outcomes.

Comparative assessment of two-phase class II treatment with Activator or Bionator followed by fixed appliances: A retrospective controlled before-and-after study.

AIM: Two-phase treatment for children with Class II malocclusion with several functional appliances is still performed by many orthodontists, while the Activator and the Bionator appliances are two of the most popular ones. Aim of this study was to compare the skeletal and dentoalveolar effects of treatment with these two appliances. METHODS: Class II children treated with Activator or Bionator in the first phase, followed by a phase of fixed appliances were included. Skeletal and dentoalveolar parameters were assessed from lateral cephalograms and analysed with linear regressions at 5%. RESULTS: A total of 89 patients (mean age 10.0 years; 47% female) were included. During the first phase, Bionator increased less the SNB (difference in mean treatment-induced changes [MD] -0.7°; 95% confidence interval [CI] -1.3 to -0.2°; P=0.01) and decreased less the ANB angle (MD 0.6°; 95% CI 0 to 1.1°; P=0.03) compared to Activator. Activator slightly increased the facial axis and Bionator reduced it (MD -1.6°; 95% CI -2.3 to -0.8°; P<0.001). Compared to Activator, the Bionator retroclined more the upper incisors (MD -2.4°; 95% CI -4.6 to -0.2°; P=0.03) and increased more the interincisal angle (MD 2.9°; 95% CI 0.5 to 5.4°; P=0.02). After the second phase (6.2 years after baseline), the only differences were a reduced facial axis (MD -1.3°; 95% CI -2.2 to -0.3°; P=0.008) and an increased maxillary rotation (MD 0.9°; 95% CI 0 to 1.8°; P=0.04) with Bionator compared to Activator. CONCLUSION: Similar dentoalveolar effects were seen overall with two-phase treatment with either appliance, with Bionator being associated with more vertical increase compared to Activator.

Validation of a fully automatic three-dimensional assessment of orthognathic surgery.

The aim of the present study was to propose and validate FAST3D: a fully automatic three-dimensional (3D) assessment of the surgical accuracy and the long-term skeletal stability of orthognathic surgery. To validate FAST3D, the agreement between FAST3D and a validated state-of-the-art semi-automatic method was calculated by intra-class correlation coefficients (ICC) at a 95 % confidence interval. A one-sided hypothesis test was performed to evaluate whether the absolute discrepancy between the measurements produced by the two methods was statistically significantly below a clinically relevant error margin of 0.5 mm. Ten subjects (six male, four female; mean age 24.4 years), class II and III, who underwent a combined three-piece Le Fort I osteotomy, bilateral sagittal split osteotomy and genioplasty, were included in the validation study. The agreement between the two methods was excellent for all measurements, ICC range (0.85-1.00), and fair for the rotational stability of the chin, ICC = 0.54. The absolute discrepancy for all measurements was statistically significantly lower than the clinical relevant error margin (p < 0.008). Within the limitations of the present validation study, FAST3D demonstrated to be reliable and may be adopted whenever appropriate in order to reduce the work load of the medical staff.

Assessment of accuracy and reproducibility of cephalometric identification performed by 2 artificial intelligence-driven tracing applications and human examiners.

OBJECTIVE: To assess the accuracy and reproducibility of cephalometric landmark identification performed by 2 artificial intelligence (AI)-driven applications (CefBot and WebCeph) and human examiners. STUDY DESIGN: Lateral cephalometric radiographs of 10 skulls containing 0.5 mm lead spheres directly placed at 10 cephalometric landmarks were obtained as the reference standard. Ten radiographs without spheres were obtained from the same skulls for identification of cephalometric points performed by the AI applications and 10 examiners. The x- and y-coordinate values of the cephalometric points identified by the AI applications and examiners were compared with those from the reference standard images using one-way analysis of variance and the Dunnet post-hoc test. The intraclass correlation coefficient (ICC) was used to evaluate reproducibility. Mean radial error (MRE) in identification was calculated with respect to the reference standard. Statistical significance was established at P < .05. RESULTS: Landmark identification by CefBot and the examiners did not exhibit significant differences from the reference standard on either axis (P > .05). WebCeph produced a significant difference (P < .05) in 4 and 6 points on the x- and y-axes, respectively. Reproducibility was excellent for CefBot and the examiners (ICC ≥ 0.9943) and good for WebCeph (ICC ≥ 0.7868). MREs of CefBot and the examiners were similar. CONCLUSION: With results similar to those of human examiners, CefBot demonstrated excellent reliability and can aid in cephalometric applications. WebCeph produced significant errors.

Assessment of upper airway changes after interpositional arthroplasty: a cephalometric analysis.

This prospective cohort study examined the changes in airway area and soft tissue parameters following interpositional arthroplasty for temporomandibular joint (TMJ) ankylosis. Ten patients with TMJ ankylosis underwent surgery, and preoperative and postoperative skeletal and soft tissue measurements were obtained. A significant rise in soft tissue parameters was observed following surgery, although only minor changes in skeletal parameters were seen. The nasoropharyngeal area, oral area, soft palate area, and tongue area were examined. After the surgery, increases in values were observed in the nasoropharyngeal area (from 3482.4 mm2 to 3618.7 mm2), the oral area (from 2731.8 mm2 to 2840.8 mm2), the soft palate area (from 204.9 mm2 to 217.3 mm2), and the tongue area (from 2577.5 mm2 to 2600.8 mm2). These findings suggest that interpositional arthroplasty can improve airway area and soft tissue dimensions, affecting the stomatognathic system's aesthetic and functional aspects. Further research is needed to validate these results and assess long-term stability.

The accuracy and reliability of different midsagittal planes in the symmetry assessment using cone-beam computed tomography.

Symmetry is an essential component of esthetic assessment. Accurate assessment of facial symmetry is critical to the treatment plan of orthognathic surgery and orthodontic treatment. However, there is no internationally accepted midsagittal plane (MSP) for orthodontists and orthognathic surgeons. The purpose of this study was to explore a clinically friendly MSP, which is more accurate and reliable than what is commonly used in symmetry assessment. Forty patients with symmetric craniofacial structures were analyzed on cone-beam computed tomography (CBCT) scans. The CBCT data were exported to the Simplant Pro software to build four reference planes that were constructed by nasion (N), basion (Ba), sella (S), odontoid (Dent), or incisive foramen (IF). A total of 31 landmarks were located to determine which reference plane is the most optimal MSP by comparing the asymmetry index (AI). The mean value of AI showed a significant difference (p < 0.05) among four reference planes. Also, the mean value of AI for all landmarks showed that Plane 2 (consisting of N, Ba, and IF) and Plane 4 (consisting of N, IF, and Dent) were more accurate and stable. In conclusion, the MSP consisting of N, Dent, and IF shows more accuracy and reliability than the other planes. Further, it is more clinically friendly because of its significant advantage in landmarking.

Evaluation of an objective staging system for assessment of cervical vertebral maturation.

BACKGROUND: The aim of this study was to evaluate an objective method for Cervical Vertebral Maturation (CVM) staging. METHODS: An initial sample of 647 Lateral Cephalometric Radiographs (LCR) were staged according to the CVM (Baccetti et al.) by 4 examiners. The final sample (n = 394) included LCR on which the staging of the 4 investigators matched. The objective staging was performed by a single operator. The sample was divided according to the maturational stages into pre-pubertal, pubertal and post-pubertal groups. Measurements were performed on the cervical vertebrae (C2, C3 and C4). The angle between posterior and superior borders for C3 and C4 was the Superior Wall Inclination Angle (SWIA). Concavity Depth (CD) for C2, C3 and C4, and Body Shape (BS) (ratio of width to height of C3 and C4). Measurements of the 3 groups were compared. RESULTS: Reliability of subjective staging was high (intra-observer reliability, 0.948; inter-observer reliability, 0.967). Good agreement was observed for the outcomes measured. Intra-observer reliability was good (0.918, 0.885 and 0.722 for CD, BS and SWIA, respectively). The same was for the inter-observer reliability results (0.902, 0.889 and 0.728 for CD, BS and SWIA, respectively). Significant differences were observed for mean values of SWIA and BS and median values of CD within maturational stage. Similar findings were observed when the outcomes were compared at different phases (P < 0.001). CONCLUSIONS: A standardized, objective staging system using linear, angular measurements and ratios was applied for the determination of cervical vertebral maturation.

Comparative assessment of facemask therapy with and without skeletal anchorage in growing Class III patients with unilateral cleft lip and palate (UCLP): A single-center, prospective randomized clinical trial.

OBJECTIVE: The purpose of this study was to evaluate the maxillary protraction effect of facemask therapy with and without skeletal anchorage in growing Class III patients with unilateral cleft lip and palate (UCLP). MATERIALS AND METHODS: Thirty patients (aged 9-13 years) with UCLP having a GOSLON score 3 were selected for this prospective clinical study. The patients were allocated into two groups using computer generated random number table. Group I (facemask therapy along with two I shaped miniplates, FM + MP) and Group II (facemask mask along with tooth-anchored appliance, FM). Skeletal and dental parameters were evaluated on pre- and post-treatment lateral cephalograms and pharyngeal airway on cone-beam computed tomography systems (CBCT) for assessment of the treatment changes. RESULTS: Both methods proved to be effective with statistically significant improvements in skeletal and dental parameters (p < .05). Skeletal parameters (e.g., SNA, convexity-point A, ANB) with the FM + MP group showed greater change compared to those with FM group (SNA, 2.56°; convexity-point A, 1.22°; ANB, 0.35°). Significant proclination of maxillary incisors was observed in the FM group as compared to FM + MP group (U1 to NA, 5.4°; 3.37 mm). A statistically significant increase in pharyngeal airway volume was noted in both groups (p < .05). CONCLUSION: While both therapies are effective in protracting the maxilla in growing patients with UCLP, the FM + MP allows for a greater skeletal correction, minimizing the dental side effects seen with FM therapy alone. Thus, FM + MP appears to be a promising adjunct in reducing the severity of Class III skeletal correction needed in patients with cleft lip and palate (CLP).

Assessment of temporomandibular joint disc position and skeletal stability after bimaxillary surgery.

PURPOSE: This study aimed to assess the correlation between temporomandibular joint (TMJ) disc position and skeletal stability and identify the cephalometric measurements associated with relapse after bimaxillary surgery. METHODS: The participants were 62 women with jaw deformities (124 joints) who underwent bimaxillary surgery. The TMJ disc position was classified into four types (anterior disc displacement (ADD), anterior, fully covered, and posterior) using magnetic resonance imaging, and cephalometric analysis was performed preoperatively and 1 week and 1 year postoperatively. The differences between pre- and 1-week postoperative values (T1) and 1-week and 1-year postoperative value (T2) were calculated for all cephalometric measurements. Moreover, the relationship between skeletal stability using cephalometric measurements, skeletal class, and TMJ disc position was analyzed. RESULTS: The participants included 28 patients in class II and 34 in class III. There was a significant difference in T2 in SNB between class II mandibular advancement cases and class III mandibular setback cases (P = 0.0001). In T2, in ramus inclination, there was a significant difference between the ADD and posterior types (P = 0.0371). Stepwise regression analysis revealed that T2 was significantly correlated with T1 for all measurements. However, the TMJ classification was not applied to all measurements. CONCLUSION: This study suggested that TMJ disc position, including ADD, could not affect skeletal stability, including the maxilla and distal segment after bimaxillary osteotomy, and short-term relapse could be related to the movement amount or angle change by surgery for all measurements.

Asymmetry in Class II subdivision malocclusion: Assessment based on 3D surface models.

INTRODUCTION: There is currently no consensus in the literature whether the aetiology of a Class II subdivision is dental, skeletal or both. The aim of this study was to identify and quantify skeletal and dental asymmetries in Class II subdivision malocclusions. METHODS: CBCTs from 33 Class II subdivision malocclusion patients were used to construct 3D volumetric label maps. Eighteen landmarks were identified. The original scan and associated 3D volumetric label map were mirrored. Registration of the original and mirrored images relative to the anterior cranial base, maxilla and mandible were performed. Surface models were generated, and 3D differences were quantified. Statistical analysis was performed. RESULTS: Anterior cranial base registration showed significant differences for fossa vertical difference, fossa roll, mandibular yaw, mandibular lateral displacement and lower midline displacement. Regional registrations showed significant differences for antero-posterior (A-P) mandibular length, maxillary roll, A-P maxillary first molar position, maxillary first molar yaw and maxillary first molar roll. Class II subdivision patients also show an asymmetric mandibular length as well as an asymmetric gonial angle. Moderate correlations were found between the A-P molar relationship and fossa A-P difference, mandibular first molar A-P difference, maxillary first molar A-P difference and maxillary first molar yaw. CONCLUSIONS: This study suggests that Class II subdivisions can result from both significant skeletal and dental factors. Skeletal factors include a shorter mandible as well as posterior and higher displacement of the fossa on the Class II side, resulting in mandibular yaw. Dental factors include maxillary and mandibular first molar antero-posterior asymmetry.

An automatic cephalometric landmark detection method based on heatmap regression and Monte Carlo dropout.

Cephalometric analysis plays an important role in orthodontic diagnosis and treatment planning. It depends on the detection of multiple landmarks, while the process is time-consuming and tedious. Although some deep learning-based automatic landmark detection algorithms have achieved excellent performance, most of them adopt multi-stage models increasing the complexity and detection time. Meanwhile, few studies focused on the uncertainty of detection results, thereby ignoring its significant clinical value. In this paper, we propose a novel approach based on heatmap regression for landmark detection, which can achieve competitive accuracy and good robustness with only one step. Furthermore, by applying Monte Carlo dropout to a U-shaped convolutional neural network, we can obtain not only the coordinate of each landmark but also the corresponding simple uncertainty, so that doctors can pay more attention to those landmarks with higher uncertainty. The evaluation results showed the mean radial error is 1.39±1.06mm and the average successful detection rate is 79.65%, 97.22% within 2mm, 4mm for the IEEE ISBI2015 Test Dataset 1, the indicators for the IEEE ISBI2015 Test Dataset 2 are 1.33±0.93mm, 80.05% and 97.53%, respectively. Our method has the potential to become an assistant tool in clinical practice. Automatic and accurate detection with uncertainty analysis is expected to help guide the doctor's judgment.

Assessment of Soft Tissue, Airway Dimension and Hyoid Bone Position in Class II Patients Treated by PowerScope Class 2 Corrector.

AIM: This study aims to assess the changes in the soft tissue, pharyngeal airway dimensions, and hyoid bone position in patients treated with PowerScope Class 2 corrector to correct the skeletal Class II pattern. MATERIALS AND METHODS: This study was conducted on a sample of 20 cases diagnosed with Class II malocclusion. The lateral cephalograms were taken before (T1) and after functional appliance therapy (T2) and were traced. The outcomes were compared for the mean changes in soft tissue, airway way dimension, and hyoid bone position. The paired t-test was used for the data comparisons wherein p < 0.05 was kept for statistical significance. RESULTS: The mean values before and after treatment for H angle, mentolabial angle, lower lip E-line, upper lip S-line, lower lip S-line, and lip strain were 19.88 ± 2.77 vs 17.13 ± 1.659, 94.09 ± 12.164 vs 101.75 ± 11.28, -2.47 ± 1.213 vs -1.38 ± 0.976, 3.99 ± 0.19 vs 2.64 ± 0.32, 9.01 ± 0.247 vs 9.43 ± 0.238, 10.24 ± 0.510 vs 10.64 ± 0.52, respectively, which were statistically significant (p < 0.05). All airway spaces (except for lower pharyngeal space) and hyoid bone parameters were significantly improved posttreatment. CONCLUSION: The facial convexity, upper E-line, Z-angle, nasolabial angle, and lower pharyngeal space did not show statistically significant changes. The rest of the soft tissue parameters, oropharyngeal air spaces, and hyoid positioning measured in the study showed significant improvement after treatment with the PowerScope appliance in Class II patients. CLINICAL SIGNIFICANCE: Class II malocclusion is the most common dental anomaly with a high degree of prevalence in the population. This study will help the clinician in understanding the improvement of soft tissue, airway dimension, and hyoid bone position changes on treatment with a fixed functional appliance for the correction of Class II cases, thereby ensuring the greater success of orthodontic therapy in the future.

Smartphone Photogrammetric Assessment for Head Measurements.

The assessment of cranial deformation is relevant in the field of medicine dealing with infants, especially in paediatric neurosurgery and paediatrics. To address this demand, the smartphone-based solution PhotoMeDAS has been developed, harnessing mobile devices to create three-dimensional (3D) models of infants' heads and, from them, automatic cranial deformation reports. Therefore, it is crucial to examine the accuracy achievable with different mobile devices under similar conditions so prospective users can consider this aspect when using the smartphone-based solution. This study compares the linear accuracy obtained from three smartphone models (Samsung Galaxy S22 Ultra, S22, and S22+). Twelve measurements are taken with each mobile device using a coded cap on a head mannequin. For processing, three different bundle adjustment implementations are tested with and without self-calibration. After photogrammetric processing, the 3D coordinates are obtained. A comparison is made among spatially distributed distances across the head with PhotoMeDAS vs. ground truth established with a Creaform ACADEMIA 50 while-light 3D scanner. With a homogeneous scale factor for all the smartphones, the results showed that the average accuracy for the S22 smartphone is -1.15 ± 0.53 mm, for the S22+, 0.95 ± 0.40 mm, and for the S22 Ultra, -1.8 ± 0.45 mm. Worth noticing is that a substantial improvement is achieved regardless of whether the scale factor is introduced per device.

Reliability and reproducibility of CBCT assessment of mandibular changes before and after treatment for Class III growing patients - an easy and quick way for evaluation.

The objective of this study was to evaluate intraobserver reliability and inter-observer reproducibility of a 3-dimensional (3D) assessment method for mandibular changes of growing patients after orthodontic treatment for Class III malocclusion.Methods Cone-beam computed tomography (CBCT) scans were performed before and after orthodontic treatment for 27 patients. During the scan, the patient was positioned such that his/her mandibular plane was parallel to floor. Three observers independently worked on the DICOM data, reconstructed the pre- and post-treatment 3D models in software, selected the stable anatomical structures (basal bone area from the lingual surface of the symphysis to the distal aspect of the first molars) to guide the automated superimposition process. Then, each observer registered 14 anatomical landmarks on the virtual models, for three times after suitable interval, to generate 3 sets of coordinates; the mean was taken as the coordinates for that particular landmark. The intraobserver reliability and inter-observer reproducibility of the method were analyzed.Results The ICCs was > 0.90 for 25 (92.6%) of the intraobserver assessments. The precision of the measurement method was < 0.3 mm in 24 (88.9%) cases. The interobserver reproducibility errors were < 0.3 mm in 21 of the 27 cases.Conclusions The intraobserver reliability and inter-observer reproducibility of 3D assessment of mandibular changes using the virtual models were excellent.

Assessment of correlation between hand-wrist maturation and cervical vertebral maturation: a fractal analysis study.

BACKGROUND: To investigate whether fractal dimension (FD) measurements from hand-wrist radiographs and lateral cephalometric radiographs are correlated with each other and with skeletal maturation stages. METHODS: In this retrospective study conducted on hand-wrist and lateral cephalometric radiographs obtained from patients between 2017 and 2023, hand-wrist maturation stages (HWMS) and cervical vertebral maturation stages (CVMS) of 144 subjects (6 to 17 years of age) were assessed radiographically. The participants were divided into nine groups (n = 16 each) based on HWMS. Fractal analysis was performed on the radiographs of the radius, the middle finger phalanges (proximal, medial and distal), and the cervical vertebral bodies (C2, C3, C4). Mean and standard deviation values, Spearman's and Pearson correlation analyses, one-way ANOVA, Kruskal-Wallis H tests and Mann-Whitney-U test were used to evaluate the data. RESULTS: Positive correlations were found between the FD values of the radius and HWMS or CVMS (r = .559, P = .001, r = .528 P = .001 respectively). The FD values of the radius were positively correlated with those of all cervical vertebrae (C2, C3, C4), proximal and medial phalanges as well as age. FD values measured from the proximal phalanx, medial phalanx and radius showed significant differences among both HWMS and CVMS (P < .05). HWMS was strongly correlated with CVMS (r = .929, P = .001). Age was strongly correlated with HWMS (r = .795, P = .001) and CVMS (r = .756, P = .001). There was a significant difference in terms of age distribution among HWMS and CVMS (P < .05). CONCLUSIONS: FD measurements on hand-wrist radiographs can provide useful information for the assessment of skeletal maturation stage. Especially, FD measurements from the radius are important and more reliable to predict skeletal maturation stage.

Assessment of landmark detection in cephalometric radiographs with different conditions of brightness and contrast using the an artificial intelligence software.

OBJECTIVES: To evaluate the reliability and reproducibility of an artificial intelligence (AI) software in identifying cephalometric points on lateral cephalometric radiographs considering four settings of brightness and contrast. METHODS AND MATERIALS: Brightness and contrast of 30 lateral cephalometric radiographs were adjusted into four different settings. Then, the control examiner (ECont), the calibrated examiner (ECal), and the CEFBOT AI software (AIs) each marked 19 cephalometric points on all radiographs. Reliability was assessed with a second analysis of the radiographs 15 days after the first one. Statistical significance was set at p < 0.05. RESULTS: Reliability of landmark identification was excellent for the human examiners and the AIs regardless of the type of brightness and contrast setting (mean intraclass correlation coefficient >0.89). When ECont and ECal were compared for reproducibility, there were more cephalometric points with significant differences on the x-axis of the image with the highest contrast and the lowest brightness, namely N(p = 0.033), S(p = 0.030), Po(p < 0.001), and Pog'(p = 0.012). Between ECont and AIs, there were more cephalometric points with significant differences on the image with the highest contrast and the lowest brightness, namely N(p = 0.034), Or(p = 0.048), Po(p < 0.001), A(p = 0.042), Pog'(p = 0.004), Ll(p = 0.005), Ul(p < 0.001), and Sn(p = 0.001). CONCLUSIONS: While the reliability of the AIs for cephalometric landmark identification was rated as excellent, low brightness and high contrast seemed to affect its reproducibility. The experienced human examiner, on the other hand, did not show such faulty reproducibility; therefore, the AIs used in this study is an excellent auxiliary tool for cephalometric analysis, but still depends on human supervision to be clinically reliable.

The Assessment of External Nasal Valve Efficiency After Le Fort I Surgery.

BACKGROUND: The present study investigated how external nasal valve function is affected after Le Fort I osteotomy using external nasal valve efficiency (ENVE) index. MATERIALS AND METHODS: Twenty-one patients who underwent Le Fort I osteotomy with or without mandibular osteotomy were included in the retrospective study. Preoperative and postoperative standardized videos of basal view of the nose during breathing were recorded, and 2 screenshots were taken, 1 in the resting position and the other after deep inspiration. External nasal valve efficiency was calculated at preoperative and postoperative periods for each patient. RESULTS: Of the 21 patients, 12 were women and 9 were men (mean age, 26.63 ± 8.20 years). The mean ENVE index was 0.75 ± 0.16 for the preoperative period and 0.82 ± 0.17 for the postoperative period. There was a significant difference between these values ( P = 0.002). When the correlation of the ENVE with maxillary movements was analyzed, the ENVE was negatively affected by maxillary impaction ( P = 0.011, r = -0.540). CONCLUSIONS: These findings imply that Le Fort I osteotomy positively affects the ENVE index. However, because of the antagonistic relation between maxillary impaction and ENVE, higher maxillary impaction amounts or isolated maxillary impaction should be carefully planned in patients with low ENVE index.

The psc-CVM assessment system: A three-stage type system for CVM assessment based on deep learning.

BACKGROUND: Many scholars have proven cervical vertebral maturation (CVM) method can predict the growth and development and assist in choosing the best time for treatment. However, assessing CVM is a complex process. The experience and seniority of the clinicians have an enormous impact on judgment. This study aims to establish a fully automated, high-accuracy CVM assessment system called the psc-CVM assessment system, based on deep learning, to provide valuable reference information for the growth period determination. METHODS: This study used 10,200 lateral cephalograms as the data set (7111 in train set, 1544 in validation set and 1545 in test set) to train the system. The psc-CVM assessment system is designed as three parts with different roles, each operating in a specific order. 1) Position Network for locating the position of cervical vertebrae; 2) Shape Recognition Network for recognizing and extracting the shapes of cervical vertebrae; and 3) CVM Assessment Network for assessing CVM according to the shapes of cervical vertebrae. Statistical analysis was conducted to detect the performance of the system and the agreement of CVM assessment between the system and the expert panel. Heat maps were analyzed to understand better what the system had learned. The area of the third (C3), fourth (C4) cervical vertebrae and the lower edge of second (C2) cervical vertebrae were activated when the system was assessing the images. RESULTS: The system has achieved good performance for CVM assessment with an average AUC (the area under the curve) of 0.94 and total accuracy of 70.42%, as evaluated on the test set. The Cohen's Kappa between the system and the expert panel is 0.645. The weighted Kappa between the system and the expert panel is 0.844. The overall ICC between the psc-CVM assessment system and the expert panel was 0.946. The F1 score rank for the psc-CVM assessment system was: CVS (cervical vertebral maturation stage) 6 > CVS1 > CVS4 > CVS5 > CVS3 > CVS2. CONCLUSIONS: The results showed that the psc-CVM assessment system achieved high accuracy in CVM assessment. The system in this study was significantly consistent with expert panels in CVM assessment, indicating that the system can be used as an efficient, accurate, and stable diagnostic aid to provide a clinical aid for determining growth and developmental stages by CVM.