[Evaluation of a modified maxillary protraction appliance for the treatment of patients with skeletal Class â ¢ malocclusion associated with crowding].

PURPOSE: To investigate the efficacy of a modified maxillary protraction appliance in patients of skeletal Class Ⅲ with crowding. METHODS: Forty patients with skeletal Class Ⅲ malocclusion were divided into two groups, with 20 patients in each group. The experimental group had molar in a neutral or distal relationship and applied a modified maxillary protraction appliance, while the control group had molar mesial relationship and applied a conventional maxillary protraction appliance. Lateral cephalometric radiographs were taken before and after treatment in both groups for comparison. SPSS 22.0 software package was used for data analysis. RESULTS: The angle measurements taken before and after treatment showed a significant increase in SNA, ANB, SN-MP and U4-SN(P＜0.01), while SNB decreased(P＜0.01) in both groups. SN-OL changes were statistically different before and after treatment in the experimental group(P＜0.05). The sagittal measurements before and after treatment in both groups showed significant alterations in all(P＜0.05) but the length of the maxillary arch in both groups. For vertical measurements, U1-PP, L1-MP, U4-SN, U6-SN, and ANS-ME all increased (P＜0.05), while the changes of U4-PP and U6-PP in the two groups before and after treatment were statistically different(P＜0.05). Compared with the control group, the experimental group had a significantly increased maxillary arch length, a more remote location at U6, and a less variable molar relationship after treatment(P＜0.01). The two groups showed a variable amount of cephalometric measurements before and after treatment: the experimental group had a significant increase in maxillary arch length, a more remote position at U6, and a smaller change in molar relationship compared to the control group(P＜0.01). CONCLUSIONS: The modified maxillary protraction appliance showed good results for maxillary protraction and pushing the molar distally in patients with skeletal Class Ⅲ with crowding at neutral or distal molar relationship.

Comparative analysis of the influence of the shapes and dimensions of dental arches on the morphotopogeometric characteristics of the facial area.

OBJECTIVE: Aim: The aim of the article is a comparative analysis of the main aspects of existing medical and diagnostic measures in patients with abnormal types of occlusal relationships and methods of mathematical and graphic reproduction of the shape of the dental arches, taking into account the individual characteristics of the maxillofacial area. PATIENTS AND METHODS: Materials and Methods: The search for relevant publications related to the objective topic was carried out through scientific databases: Scopus, PubMed, BVS and Scielo. CONCLUSION: Conclusions: The analysis of regression models of the reproduction of individual characteristics of the dental arch of the jaws will avoid errors that occur when comparing the actual sizes with their statistical norm, which will allow to correctly determine the proportionality and ratio of dif f erent departments of the dental and jaw system, the necessary amount of orthodontic measures in the treatment of anomalies of the dental arches.

Developing an eyeball positioning method in the eye orbit for craniofacial identification in Korean population.

We analysed the skulls and faces of Korean subjects using anthropometric methods to understand the anatomical characteristics of the eyeball and eye orbit region of Korean population and to determine the correlations between the hard and soft tissues around the eyeball and eye orbit region. In total, 82 sections in the region were measured to determine the correlations; among them, 34 showed significant differences by sex, and 6 showed significant differences by age. As the distance from the centre of the eye lens to the eye orbit is calculated as a ratio, we determined that the centre of the eye lens is located relatively on the lateral and superior position in each eye orbit in front view. Fourteen sections that could be used for craniofacial reconstruction/approximation in men and women were selected. Regression equations were derived according to the correlation of each section, and their reliabilities were verified by out of sample validation tests. Therefore, our results increase the accuracy of eyeball position determination, which would be useful for more efficient craniofacial reconstruction/approximation of the Korean population and should improve the efficiency of facial recognition.

Craniofacial morphological variability in orthodontic patients with non-syndromic orofacial clefts: an approach using geometric morphometrics.

OBJECTIVES: Orofacial clefts are complex congenital anomalies that call for comprehensive treatment based on a thorough assessment of the anatomy. This study aims to examine the effect of cleft type on craniofacial morphology using geometric morphometrics. MATERIALS AND METHODS: We evaluated lateral cephalograms of 75 patients with bilateral cleft lip and palate, 63 patients with unilateral cleft lip and palate, and 76 patients with isolated cleft palate. Generalized Procrustes analysis was performed on 16 hard tissue landmark coordinates. Shape variability was studied with principal component analysis. In a risk model approach, the first nine principal components (PC) were used to examine the effect of cleft type. RESULTS: We found statistically significant differences in the mean shape between cleft types. The difference is greatest between bilateral cleft lip and palate and isolated cleft palate (distance of means 0.026, P = 0.0011). Differences between cleft types are most pronounced for PC4 and PC5 (P = 0.0001), which together account for 10% of the total shape variation. PC4 and PC5 show shape differences in the ratio of the upper to the lower face, the posterior mandibular height, and the mandibular angle. CONCLUSIONS: Cleft type has a statistically significant but weak effect on craniofacial morphological variability in patients with non-syndromic orofacial clefts, mainly in the vertical dimension. CLINICAL RELEVANCE: Understanding the effects of clefts on craniofacial morphology is essential to providing patients with treatment tailored to their specific needs. This study contributes to the literature particularly due to our risk model approach in lieu of a prediction model.

The taxonomy of Sahelanthropus tchadensis from a craniometric perspective.

Sahelanthropus tchadensis has raised much debate since its initial discovery in Chad in 2001, given its controversial classification as the earliest representative of the hominin lineage. This debate extends beyond the phylogenetic position of the species, and includes several aspects of its habitual behavior, especially in what regards its locomotion. The combination of ancestral and derived traits observed in the fossils associated with the species has been used to defend different hypotheses related to its relationship to hominins. Here, the cranial morphology of Sahelanthropus tchadensis was assessed through 16 linear craniometric measurements, and compared to great apes and hominins through Principal Component Analysis based on size and shape and shape information alone. The results show that S. tchadensis share stronger morphological affinities with hominins than with apes for both the analysis that include size information and the one that evaluates shape alone. Since TM 266-01-060-1 shows a strong morphological affinity with the remaining hominins represented in the analysis, our results support the initial interpretations that S. tchadensis represents an early specimen of our lineage or a stem basal lineage more closely related to hominins than to Panini.

Changes in the arch width and buccal corridor after fixed orthodontic treatment with Damon self-ligating system: premolar extraction vs. non-extraction.

INTRODUCTION: Extraction vs. non-extraction is a crucial decision in orthodontic therapy. OBJECTIVE: The aim of the present study was to investigate the changes in the dental arch width and buccal corridor after orthodontic treatment using extraction and non-extraction therapy with Damon self-ligating system. MATERIAL AND METHODS: This retrospective study consisted of 35 patients (20 female and 15 male patients with median age of 12.5 years), treated by extracting 4 or 2 premolars, and 37 patients (16 female and 21 male patients with the median age of 12.8 years), treated without premolar extraction. Both groups were treated with Damon self-ligating system. Plaster models before (T0) and after (T1) treatment were measured, and the arch width values were determined at the level of the first molars, second premolars, canines and palatal rugae. Buccal corridor width was measured using the extraoral images at T0 and T1. Paired t-test was used for the analysis of the normally distributed data, and Wilcoxon Mann-Whitney U test was used for the data with non-normal distribution. Values of p<0.05 were set as statistically significant. RESULTS: The upper intercanine width increased significantly in both groups (p<0.01). In the non-extraction group, the arch width increased significantly in the maxillary second premolar and first molar region (p<0.01) as well as in the region of the canines (p=0.04), second premolars (p=0.01) and first molars (p<0.01) of the mandible. The buccal corridor decreased significantly in the non-extraction group (p<0.01). CONCLUSION: Premolar extraction in combination with Damon self-ligating system did not lead to reduction of the dental arch width in the maxilla, nor did it increase the size of the buccal corridors.

Does mandibular advancement ortho-surgical procedure cause condyle changes? A case-series analysis.

INTRODUCTION: Mandibular advancement surgery corrects bone bases while establishing patients' functional and aesthetic rehabilitation. However, little is known about the results of this procedure in the structures that make up the stomatognathic system, as the condyles. OBJECTIVE: This study aimed to evaluate the structural and positional changes of mandibular condyles in ortho-surgical patients who underwent mandibular advancement surgery. MATERIAL AND METHODS: A prospective investigation was conducted with cone-beam computed tomography images. Using Dolphin Imaging® software, seven ortho-surgical patients with Angle Class II malocclusion and mandibular deficiency were evaluated. The images assessed were obtained at pre-surgical phase and after, at least, 1 year of the procedure. To study the structural and positional changes of condyles, linear and angular measurements were obtained, and the right and left sides of patients were compared. Descriptive statistical analysis was performed and, in order to verify possible significant differences, normality tests (Kolmogorov-Smirnov) were applied, followed by a paired t-test to define significance. RESULTS: For all measures evaluated in this study, no statistically significant differences were found. CONCLUSION: The ortho-surgical procedure performed did not change the structure and position of the condyles of patients who underwent surgical mandibular advancement. Right and left mandibular condyles behaved similarly, suggesting stability and condylar adaptation after surgery.

A digitalized analysis of incisal changes among orthodontically treated patients: A retrospective comparative study.

Background: To compare incisor angulation and/or position changes among orthodontically treated patients with metal brackets and clear aligners. Methods: A total of sixty-two participants of both sexes, aged-16-40 years old, with CL I skeletal pattern and mild crowding following strict eligibility criteria were included. The patients were divided into two groups based on their treatment approach. Pre and post lateral cephalograms were collected from Riyadh Elm University (REU) and then digitally analyzed using WEBCEPH (Medical Image Analysis) software. Eight angular and two linear measurements were used for the assessment. Results: The upper incisor angulation and position showed statistically significant differences when orthodontic clear aligners were used. In contrast, no significant difference was observed with the conventional orthodontic treatment. However, the upper incisal palatal root torque decreased after clear aligner therapy compared to conventional treatment. The inter-incisal angle demonstrated a significant increase with clear aligners compared to conventional treatment. Conclusions: The current study revealed the importance of definitive guidelines upon and after treatment, in addition to determining incisor changes. Orthodontic clear aligners are distinct from conventional treatments in controlling the incisors' angulation and position. The expansion treatment modality precedes Interproximal reduction in increasing the arch perimeter.

Evaluation of Mandibular Projection in Class II Division 2 Subjects Following Orthodontic Treatment Using Clear Aligners.

AIM: The purpose of this study was to evaluate the mandibular growth and/or projection following maxillary incisor proclination, overbite correction, and maxillary dentoalveolar expansion without the use of any class II mechanics, in growing class II division 2 patients treated with clear aligners. MATERIALS AND METHODS: Before and after treatment cone-beam computed tomographic (CBCT) generated lateral and posteroanterior cephalograms of thirty-two patients with skeletal class II division 2, 16 in the treatment group and 16 in the untreated group, were reviewed to evaluate treatment-related changes. Upper incisors were proclined and protruded, as well as upper arch expansion and overbite correction were performed as part of their regular treatment. Cephalometric analysis was performed to evaluate skeletal and dental changes. Unpaired statistical t-tests were performed to determine if significant skeletal class II correction was achieved in the treatment group. RESULTS: In the treatment group, after treatment, the upper incisors became more proclined and protruded, and the inter-molar width increased while the overbite was reduced compared to the control group. An increase in skeletal mandibular growth and forward projection was also observed, thus contributing to an improvement of the sagittal skeletal relationship as evidenced by ANB and Wits values compared to the control group. CONCLUSION: A combination of upper incisor proclination, correction of deep overbite, and maxillary dentoalveolar expansion using clear aligners appears to contribute to an improvement of the skeletal class II relationship in growing patients with class II division 2. CLINICAL SIGNIFICANCE: This study shows that unlocking the mandible by correcting a deep overbite, proclining upper incisors, and expanding the upper arch in growing class II division 2 patients can improve skeletal class II using clear aligners. How to cite this article: Mirzasoleiman P, El-Bialy T, Wiltshire WA, et al. Evaluation of Mandibular Projection in Class II Division 2 Subjects Following Orthodontic Treatment Using Clear Aligners. J Contemp Dent Pract 2024;25(4):295-302.

Comparative Evaluation of Digital Cephalometric Tracing Applications on Mobile Devices and Manual Tracing.

BACKGROUND Cephalometric radiography evaluates facial skeleton development and aids in diagnosis and treatment phases (pre and post) in orthodontics. This study aimed to compare digital cephalometric tracing using a smartphone application (App), a tablet-based platform, and manual tracing in 30 orthodontic patients. MATERIAL AND METHODS Thirty orthodontic pretreatment, criteria based, lateral cephalometric radiographs were analyzed/grouped for Steiner analysis parameters (5 skeletal, 3 dentals, 1 soft tissue) by 3 tracing methods [manual - group (Gp M), smartphone (Android - OS9) - Gp S, tablet (Apple - IOS13) - Gp T) after mandatory standardization/calibration. Measurements include 5 angular (SNA, SNB, ANB, SNMPA, SNOP), 3 linear U1NA, L1NB, U1L1, and 1 soft tissue (S line) (millimeters and degrees). Inter-examiner rating was determined using Dahlberg's test. After normality distribution testing (Shapiro-Wilk), data were analyzed using one-way analysis of variance (ANOVA) for group differences. Homogeneity of variance was verified using the Levene test. Differences were determined on probability value of (p≤0.05). RESULTS The results showed that Steiner's analysis parameters were similar in all groups with homogenous variances. Highest differences in mean values were found for L1NB, U1L1, and S line measurement, with higher values being observed in Gp S tracings. However, these differences were not statistically significant (p≤0.05). All parameters, irrespective of being measured in either degrees or millimeters, had means comparable to each other. CONCLUSIONS Smartphone and tablet-based applications produced tracings that were comparable and reliable when compared to conventional manual tracings. Standardization of images, processing, printing, and calibration of devices is important to achieve good results.

Can artificial intelligence-driven cephalometric analysis replace manual tracing? A systematic review and meta-analysis.

OBJECTIVES: This systematic review and meta-analysis aimed to investigate the accuracy and efficiency of artificial intelligence (AI)-driven automated landmark detection for cephalometric analysis on two-dimensional (2D) lateral cephalograms and three-dimensional (3D) cone-beam computed tomographic (CBCT) images. SEARCH METHODS: An electronic search was conducted in the following databases: PubMed, Web of Science, Embase, and grey literature with search timeline extending up to January 2024. SELECTION CRITERIA: Studies that employed AI for 2D or 3D cephalometric landmark detection were included. DATA COLLECTION AND ANALYSIS: The selection of studies, data extraction, and quality assessment of the included studies were performed independently by two reviewers. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A meta-analysis was conducted to evaluate the accuracy of the 2D landmarks identification based on both mean radial error and standard error. RESULTS: Following the removal of duplicates, title and abstract screening, and full-text reading, 34 publications were selected. Amongst these, 27 studies evaluated the accuracy of AI-driven automated landmarking on 2D lateral cephalograms, while 7 studies involved 3D-CBCT images. A meta-analysis, based on the success detection rate of landmark placement on 2D images, revealed that the error was below the clinically acceptable threshold of 2 mm (1.39 mm; 95% confidence interval: 0.85-1.92 mm). For 3D images, meta-analysis could not be conducted due to significant heterogeneity amongst the study designs. However, qualitative synthesis indicated that the mean error of landmark detection on 3D images ranged from 1.0 to 5.8 mm. Both automated 2D and 3D landmarking proved to be time-efficient, taking less than 1 min. Most studies exhibited a high risk of bias in data selection (n = 27) and reference standard (n = 29). CONCLUSION: The performance of AI-driven cephalometric landmark detection on both 2D cephalograms and 3D-CBCT images showed potential in terms of accuracy and time efficiency. However, the generalizability and robustness of these AI systems could benefit from further improvement. REGISTRATION: PROSPERO: CRD42022328800.

Predictability of expansion movements performed by clear aligners in mixed dentition in both arches: a retrospective study on digital casts.

BACKGROUND: to evaluate the predictability of expansion achieved in patients in early mixed dentition treated with Clear Aligners (CA), analyzing the efficiency of the expansion at the end of the first set of aligners and at the end of the therapy in the upper and lower arch. METHODS: 36 patients (20 F, 16 M; mean age 8.3 ± 1.5 years) were selected retrospectively from the Department of Orthodontics of the Hospital of Rome "Tor Vergata". All subjects were treated with CA with no other auxiliaries than attachments. For each patient a standardized sequential expansion protocol was planned for both arches. Digital dental casts were created at three observation periods from an intraoral scanner: prior to treatment (T0), at the end of the first set of aligners (T1), at the end of treatment (T2). The 3D models in planned position determined by the first Clincheck (CC) were obtained for comparison with T1 and T2. Six linear transversal measurements were used to evaluate the dimensional changes and the predictability of expansion movements, comparing T1-CC and T2-CC. RESULTS: a statistically significant increase within the pre-treatment and the final outcomes for all the variables examined was found. In the upper arch, the greatest level of predictability was detected at the level of the first (46.44%) and second deciduous molar width (44.95%) at T1. The analysis of T2-CC changes showed a significant increase in the percentage of predictability of expansion at the level of the first permanent molars, at mesial (54.86%) and distal (58.92%) width. In the lower arch, a higher percentage of predictability than the upper arch was reported at T1-CC and T2-CC, with the greatest values at the level of second (T1-CC: 48.70%; T2-CC: 75.32%) and first deciduous molar width (T1-CC: 45.71%; T2-CC: 72.75%). CONCLUSIONS: CA can induce significant transversal increments. The predictability of expansion is variable, but it did not exceed the 50% during the first set of aligners. It was necessary to apply refinement set to achieve a good predictability for expansion of about 70%. The expansion in the lower arch was observed to be more predictable than in the upper arch.

Facial soft-tissue shape changes after fixed edgewise treatment with premolar extraction in individual artificial-intelligence-classified facial profile patterns.

OBJECTIVE: To examine the patterns of pretreatment facial soft tissue shape in orthodontic cases with premolar extraction using artificial intelligence (AI) and to investigate the corresponding changes. METHODS: One hundred and fifty-two patients who underwent orthodontic treatment with premolar extraction were enrolled. Lateral cephalograms were obtained before and after the treatment. For each record, the outlines of the nose-lip-chin profile and corresponding 21 cephalometric variables were extracted. The AI method classified pretreatment records into three subject groups based on the feature variables extracted from the outline. Dentoskeletal and soft tissue facial form changes observed after treatment were compared statistically (P < 0.05) between the groups using ANOVA. Multivariate regression models were used for each group. RESULTS: Group 1 (n = 59) was characterized by Class II high-angle retrognathic mandible with an incompetent lip, group 2 (n = 55) by Class I malocclusion with retruded and thin lips, and group 3 (n = 38) by Class I malocclusion with an everted superior lip before treatment. The ratios of anteroposterior soft tissue to hard tissue movements in Group 1 were 56% (r = 0.64) and 83% (r = 0.75) for the superior and inferior lips, respectively, whereas those in Group 2 were 49% (r = 0.78) and 91% (r = 0.80), and 40% (r = 0.54) and 79% (r = 0.70), respectively, in Group 3. CONCLUSIONS: The modes of facial form changes differed depending on the pre-treatment profile patterns classified by the AI. This indicates that the determination of the pre-treatment profile pattern can help in the selection of soft tissue to hard tissue movement ratios, which helps estimate the post-treatment facial profile with a moderate to high correlation.

Mandibular distraction osteogenesis in children with Pierre Robin sequence: long-term analysis of teeth and jaw growth.

Treatment of children with Pierre Robin sequence (PRS) having a hypoplastic mandible and upper airway distress after birth may consist of external distraction devices. Shape anomalies of the permanent molars and positional changes due to surgery have been documented. The aim of this study is to compare the long-term effects (>5 years) on the growth pattern of PRS-patients treated with an external mandibular distraction device with no-surgery cases and to investigate the dental development or damage. A retrospective cohort study was performed. PRS-patients with and without surgery were included. A digital cephalometric analysis was made to evaluate the growth pattern of the mandible between groups as well as with normal values. Nine of 19 patients underwent an external mandibular distraction. All children were extubated after 4-5 days with no signs of respiratory distress. Screw and device loosening presented in one patient. The articular and sellar angles were significantly larger and smaller, respectively, in the Surgery group. Mandibular distraction surgery might result in a 'growth boost' compared to the No-surgery group. No significant difference in dental development was found. Mandibular distraction osteogenesis is an effective way of relieving severe upper airway obstruction.

The Frequency of Occipital Spurs in Relation to the Cephalic Index: An Anatomorphometric Cone Beam CT Study.

BACKGROUND: The occipital spur (OS) can be described as an abnormal elongation of the external occipital protuberance (EOP). The cephalic index (CI) refers to the ratio of width to length in any skull. AIM: The aim of the present study was to evaluate the frequency and types of OS. It also aimed to determine the mean CI and the distribution of skull types using cone beam computed tomography (CBCT). And to determine if there was a relationship between the cephalic index and the presence and types of OS. METHODS: CBCT scans from 523 patients were included in the study. OSs were classified as type 1 (flat), type 2 (crest), and type 3 (spine). Skull length and width were measured on axial sections and the CI was calculated. Based on the cephalic index (CI), skull types were classified as dolichocephalic (CI < 75), mesocephalic (75 < CI < 80), brachycephalic (80 < CI < 85), and hyperbrachycephalic (CI > 85). RESULTS: The most common cranial types in the study group were brachycephalic (44.7%), mesocephalic (28.3%), hyperbrachycephalic (21.2%), and dolichocephalic (5.7%). Regarding the presence of OS, 54.3% of the participants had no OS, 23.1% had flat type, 15.3% had crest type, and 7.2% had spin type OS. There was a statistically significant difference (P < 0.05) in the frequency of OS according to skull type. CONCLUSION: This study, the first to evaluate CI and OS using CBCT, concludes that brachycephaly is the most common cranial type. OS is more common in mesocephalic and dolichocephalic skulls, at older ages, and in males.

The efficiency of a customized distalizer with Variety SP® screws anchored on palatal miniscrews for upper molar distalization.

OBJECTIVE: To assess the effectiveness of a customized distalizer with Variety SP® screws anchored on palatal miniscrews for upper molar distalization. METHODS: Seventeen patients aged between 12.5 and 24 years underwent distalization with a customized distalizer. Lateral cephalogram and cast analysis were performed before and after distalization. Linear and angular parameters of the upper first molar, first premolar, and central incisor were assessed. RESULTS: Distalization with the force passing near the center of resistance (CRes) of the upper first molars resulted in distal movement, with minimal distal tipping (2.8 ±â€Š0.45°, p< 0.05). However, distalization passing occlusal to the CRes led to greater distal tipping (13.6 ±â€Š1.63°, p< 0.05). Statistically significant spontaneous distal tipping and distal movement of the upper first premolars occurred, with a mean of 6.2 ±â€Š1.24° (p< 0.05) and 0.68 ±â€Š0.34 mm (p< 0.05), respectively. The positional change of the upper central incisors presented a mean of -0.23 ±â€Š0.1 mm (p> 0.05) and 2.65 ±â€Š1.1° (p< 0.05). Upper first molar intrusion was statistically significant, with a mean of 0.88 ±â€Š0.2 mm (p< 0.05). Upper right and left first molars rotation towards palatal midline presented mean of 4.1 ±â€Š0.19° (p< 0.05) and 3.4  ±â€Š0.1° (p< 0.05), respectively. Additionally, the distance between upper right and left first molars increased significantly, with a mean of 2.54 ±â€Š0.01 mm (p< 0.05). CONCLUSION: The study successfully demonstrated the efficiency of molar distalization without anchorage loss using a customized distalizer anchored on palatal miniscrews.

Estimating mandibular growth stage based on cervical vertebral maturation in lateral cephalometric radiographs using artificial intelligence.

INTRODUCTION: Determining the right time for orthodontic treatment is one of the most important factors affecting the treatment plan and its outcome. The aim of this study is to estimate the mandibular growth stage based on cervical vertebral maturation (CVM) in lateral cephalometric radiographs using artificial intelligence. Unlike previous studies, which use conventional CVM stage naming, our proposed method directly correlates cervical vertebrae with mandibular growth slope. METHODS AND MATERIALS: To conduct this study, first, information of people achieved in American Association of Orthodontics Foundation (AAOF) growth centers was assessed and after considering the entry and exit criteria, a total of 200 people, 108 women and 92 men, were included in the study. Then, the length of the mandible in the lateral cephalometric radiographs that were taken serially from the patients was calculated. The corresponding graphs were labeled based on the growth rate of the mandible in 3 stages; before the growth peak of puberty (pre-pubertal), during the growth peak of puberty (pubertal) and after the growth peak of puberty (post-pubertal). A total of 663 images were selected for evaluation using artificial intelligence. These images were evaluated with different deep learning-based artificial intelligence models considering the diagnostic measures of sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). We also employed weighted kappa statistics. RESULTS: In the diagnosis of pre-pubertal stage, the convolutional neural network (CNN) designed for this study has the higher sensitivity and NPV (0.84, 0.91 respectively) compared to ResNet-18 model. The ResNet-18 model had better performance in other diagnostic measures of the pre-pubertal stage and all measures in the pubertal and post-pubertal stages. The highest overall diagnostic accuracy was also obtained using ResNet-18 model with the amount of 87.5% compared to 81% in designed CNN. CONCLUSION: The artificial intelligence model trained in this study can receive images of cervical vertebrae and predict mandibular growth status by classifying it into one of three groups; before the growth spurt (pre-pubertal), during the growth spurt (pubertal), and after the growth spurt (post-pubertal). The highest accuracy is in post-pubertal stage with the designed networks.

Deep learning for 3D cephalometric landmarking with heterogeneous multi-center CBCT dataset.

Cephalometric analysis is critically important and common procedure prior to orthodontic treatment and orthognathic surgery. Recently, deep learning approaches have been proposed for automatic 3D cephalometric analysis based on landmarking from CBCT scans. However, these approaches have relied on uniform datasets from a single center or imaging device but without considering patient ethnicity. In addition, previous works have considered a limited number of clinically relevant cephalometric landmarks and the approaches were computationally infeasible, both impairing integration into clinical workflow. Here our aim is to analyze the clinical applicability of a light-weight deep learning neural network for fast localization of 46 clinically significant cephalometric landmarks with multi-center, multi-ethnic, and multi-device data consisting of 309 CBCT scans from Finnish and Thai patients. The localization performance of our approach resulted in the mean distance of 1.99 ± 1.55 mm for the Finnish cohort and 1.96 ± 1.25 mm for the Thai cohort. This performance turned out to be clinically significant i.e., ≤ 2 mm with 61.7% and 64.3% of the landmarks with Finnish and Thai cohorts, respectively. Furthermore, the estimated landmarks were used to measure cephalometric characteristics successfully i.e., with ≤ 2 mm or ≤ 2° error, on 85.9% of the Finnish and 74.4% of the Thai cases. Between the two patient cohorts, 33 of the landmarks and all cephalometric characteristics had no statistically significant difference (p < 0.05) measured by the Mann-Whitney U test with Benjamini-Hochberg correction. Moreover, our method is found to be computationally light, i.e., providing the predictions with the mean duration of 0.77 s and 2.27 s with single machine GPU and CPU computing, respectively. Our findings advocate for the inclusion of this method into clinical settings based on its technical feasibility and robustness across varied clinical datasets.

Evaluation of the soft tissue facial profile in different skeletal malocclusions in relation to age.

BACKGROUND: The aim of the study was to assess the thickness of the soft tissue facial profile (STFP) in relation to the skeletal malocclusion, age and gender. METHODS: All patients, aged 7-35 years, who were seeking orthodontic treatment at the Department of Orthodontics, Medical University of Warsaw between 2019 and 22 were included in the study. All patients had lateral head radiographs taken before the treatment. The cephalometric analysis was performed including the STFP analysis. The patients were allocated to one of six groups based on age and skeletal relations (ANB angle). The minimum number of patients in each group was 60 with equal gender distribution. The STFP analysis included ten linear measurements. RESULTS: A total of 300 patients were included in the study and allocated to five groups. Group 6 (growing patients with skeletal Class III malocclusion) was not included in the study as it failed to achieve the assumed group size. There were significant differences in the thickness of the STFP in relation to the skeletal malocclusions. Adults with skeletal Class III malocclusion had significantly thicker subnasal soft tissues compared to patients with skeletal Class I and Class II malocclusions. The thickness of the lower lip in patients with Class II skeletal malocclusion was significantly bigger compared to the other groups. Children and adolescents with Class II malocclusions had thicker lower lip in comparison to the group with Class I malocclusion. The majority of the STFP measurements were significantly smaller in children and adolescents compared to adults. The thickness of the STFP in males was significantly bigger in all age groups compared to females. CONCLUSIONS: The thickness of facial soft tissues depends on the patient's age and gender. The degree of compensation of the skeletal malocclusion in the STFP may be a decisive factor during orthodontic treatment planning regarding a surgical approach or a camouflage treatment of skeletal defects.

Functional needs in orthognathic patients with different sagittal skeletal discrepancies.

OBJECTIVES: This retrospective study aimed to evaluate the relationship between the Index of Orthognathic Functional Treatment Need (IOFTN) and sagittal skeletal discrepancy (ANB angle) among orthognathic patients. STUDY DESIGN: Records of 403 orthognathic patients (229 females/174 males, aged 16-50 years) were reviewed. Malocclusion type (incisor-based), sagittal skeletal relationship (ANB angle), and IOFTN scores were documented. Spearman correlation coefficient (r) and scatter plots were utilized to examine the relationship between functional need (IOFTN scores) and sagittal skeletal discrepancy (ANB angle). Regression analyses were conducted to determine the extent to which variations in IOFTN scores could be attributed to variations in ANB angles. RESULTS: Class III malocclusion/sagittal skeletal pattern were most prevalent (62.3%). The Spearman correlation coefficient (r) for the entire sample was -0.297 (P < .001), indicating a weak negative correlation. Linear regression analysis demonstrated a coefficient of determination of 0.069, indicating that approximately 6.9% of the variance in IOFTN data could be accounted for by variations in ANB angles. Upon stratifying data by different malocclusions, coefficients of determination were 0.065, 0.034, and 0.089 for class I, II, and class III malocclusions, respectively. CONCLUSION: The observed linear relationships between sagittal skeletal discrepancy (ANB angle) and IOFTN score were weak and lacked clinical significance.