Comparison of semi and fully automated artificial intelligence driven softwares and manual system for cephalometric analysis.

BACKGROUND: Cephalometric analysis has been used as one of the main tools for orthodontic diagnosis and treatment planning. The analysis can be performed manually on acetate tracing sheets, digitally by manual selection of landmarks or by recently introduced Artificial Intelligence (AI)-driven tools or softwares that automatically detect landmarks and analyze them. The use of AI-driven tools is expected to avoid errors and make it less time consuming with effective evaluation and high reproducibility. OBJECTIVE: To conduct intra- and inter-group comparisons of the accuracy and reliability of cephalometric tracing and evaluation done manually and with AI-driven tools that is WebCeph and CephX softwares. METHODS: Digital and manual tracing of lateral cephalometric radiographs of 54 patients was done. 18 cephalometric parameters were assessed on each radiograph by 3 methods, manual method and by using semi (WebCeph) and fully automatic softwares (Ceph X). Each parameter was assessed by two investigators using these three methods. SPSS was then used to assess the differences in values of cephalometric variables between investigators, between softwares, between human investigator means and software means. ICC and paired T test were used for intra-group comparisons while ANOVA and post-hoc were used for inter-group comparisons. RESULTS: Twelve out of eighteen variables had high intra-group correlation and significant ICC p-values, 5 variables had relatively lower values and only one variable (SNO) had significantly low ICC value. Fifteen out of eighteen variables had minimal detection error using fully-automatic method of cephalometric analysis. Only three variables had lowest detection error using semi-automatic method of cephalometric analysis. Inter-group comparison revealed significant difference between three methods for eight variables; Witts, NLA, SNGoGn, Y-Axis, Jaraback, SNO, MMA and McNamara to Point A. CONCLUSION: There is a lack of significant difference among manual, semiautomatic and fully automatic methods of cephalometric tracing and analysis in terms of the variables measured by these methods. The mean detection errors were the highest for manual analysis and lowest for fully automatic method. Hence the fully automatic AI software has the most reproducible and accurate results.

Analysis of facial features and prediction of lip position in skeletal class III malocclusion adult patients undergoing surgical-orthodontic treatment.

OBJECTIVES: This study presents a retrospective study aimed to analyze the facial features at each stage of surgical-orthodontic treatment for skeletal class III malocclusion, and predict the changes in the lips after treatment. MATERIALS AND METHODS: There were 49 skeletal class III malocclusion patients treated with bimaxillary surgery and orthodontic treatment enrolled in this study. Lateral cephalograms were obtained before treatment (T0), 1 month before surgery (T1), 1 month after surgery (T2), and after debonding (T3) for cephalometric measurements. After the measurement of the required variables, paired t-test, Pearson's correlation analysis, and multiple linear regression were performed using SPSS 19.0. RESULTS: The main factors associated with changes in the upper lip included ΔUIE-V, ΔA-V, ΔU1A-V, and ΔL1A-V, and those associated with changes in the lower lip included ΔLIE-V, ΔL1A-V, ΔB-V, ΔPog-V, and Δfacial angle. The predicted regression equation for the horizontal change in the upper lip was represented as ΔUL-vertical reference line (VRL) = 9.430 + 0.779 (ΔUIE-VRL) - 0.542(VULT) (P < 0.05) with a mean error of 1.04 mm; the corresponding equation for the lower lip was ΔLL-VRL = -1.670 + 0.530 (ΔB-VRL) + 0.360 (Ls-E) + 0.393 (ΔLIE-VRL) (P < 0.05), with a mean error of 1.51 mm. CONCLUSIONS: This study explored the relationship between orthognathic surgery and changes in the lips and obtained the predictive equations of lip position after treatment by using multiple linear regression, which likely offers a reference for prediction of soft tissue changes before surgical-orthodontic treatment in patients with skeletal class III malocclusion. CLINICAL RELEVANCE: The findings can help dentists to rapidly predict the lip changes after surgical-orthodontic treatment in patients with skeletal class III malocclusion. The study has been registered with the Chinese Clinical Trial Registration (No: ChiCTR1800017694).

Three-dimensional analysis of lip soft tissue changes and related jaw changes in patients with skeletal class III malocclusion and facial asymmetry.

OBJECTIVE: To investigate three-dimensional soft tissue changes of lips and related jaw changes in patients with skeletal class III malocclusion and facial asymmetry using cone-beam computerized tomography (CBCT). METHOD: This study included 46 CBCT scans of patients with aforementioned character before (T1) and 6-12 months after orthognathic surgery (T2). Subjects were divided into 2 groups according to two types of orthognathic surgery namely, the one-jaw surgery group who underwent bilateral sagittal splint ramus osteotomy (BSSRO) and the two-jaw surgery group who underwent Le Fort I osteotomy and BSSRO. Mimics 19.0 software are used for model reconstruction, landmark location and three-dimensional cephalometric analysis. Descriptive statistics and correlation analyses are used to investigate jaw hard tissue and lip soft tissue changes. RESULTS: In one-jaw group, the mandible shows changes in contour and position (p < 0.05), and the surgery causes changes of lip structure on the deviated side. While in two-jaw group, jaws only show changes in spatial position, and surgery changes contour of bilateral lips and nasolabial angle (p < 0.05). At the same time, lip symmetry increases significantly in both groups postoperatively. CONCLUSIONS: Orthognathic surgery can improve lip aesthetics in patients with skeletal class III malocclusion and facial asymmetry. However, changes induced by two surgical approaches are different. Surgeons should have a clear acquaintance with this difference to deal with different situations.

Effects of the sander bite jumping appliance in patients with class ii malocclusion before growth peak.

Sander bite jumping appliance (BJA) is a functional appliance used to correct Class II malocclusion in growing patients. The aim of this study was to identify the dento-skeletal effects in patients treated with BJA before growth peak and to compare these effects with the ones obtained in a similar group treated with the Andresen activator (AA). Twenty subjects with class II relationship of the skeletal bases and cervical vertebrae maturation stage 1 or 2 were enrolled in the study and treated with BJA. This group were compared to 14 subjects treated with AA. Cephalometric analyses were carried out using landmarks derived from the analyses of Pancherz, Ricketts, Tweed and Steiner. After treatment with BJA Pg/OLp increase was 7.40±3.81 mm (P<0.001); Pg/OLp+Co/OLp significantly heightened from T0 to T1 (T0: 82.20±4.65 mm vs T1: 89.62±4.27, P<0.001). Overjet (is/OLp - ii/OLp) significantly decreased from T0 to T1 (T0: 7.40±2.31 mm vs T1: 3.05±1.34 mm, P<0.001). Molar relationship improved passing from 1.46±1.68 mm at T0 to -3.56±2.04 mm at T1 (P<0.001). No statistically significant differences were found between BJA and AA groups at T0 and T1. BJA treatment determined a Class II malocclusion correction in all patients. The correction of molar relationship was mainly due to the increase in mandibular length; the correction of the overjet was due to the increase in mandibular length, to the slight pro-inclination of the lower incisors and the mild retro-inclination of the upper incisors. No significant differences were found in effectiveness between BJA and AA.

Comparison of Diagnostic Validity of Cephalometric Analyses of the ANB Angle and Tau Angle for Assessment of the Sagittal Relationship of Jaw and Mandible.

BACKGROUND: Cephalometric analysis is an essential tool used in orthodontic diagnosis and treatment planning. The aim of this study was to evaluate the reliability and repeatability of new cephalometric points introduced in Tau angle analysis, in contrast to the gold standard, which is the analysis of the ANB angle. For this purpose, an attempt was made to assess the repeatability and reliability of the introduction of anthropometric points by evaluating both inter- and intraobserver parameters, as well as the agreement among the orthodontists participating in the study. METHODS: Repeatability and reliability assessments for all six anthropometric points (N, A, B, T, M, G) used in the analysis of the ANB and Tau angles were conducted individually by 29 orthodontists. This assessment was performed in triplicate on the day of the study, on the day following the first study, and on the seventh day after the second study. Measurement errors for the ANB and Tau angles were evaluated using the Dahlberg formula and intraclass correlation coefficients (ICCs). RESULTS: The orthodontists in the study measured sagittal discrepancy significantly more accurately using the ANB angle compared to the Tau angle (p < 0.001). The Dahlberg error for measuring the Tau angle was three times greater than that for the ANB angle (p < 0.001). Additionally, the ICC for the Tau angle was more than 3.5 times smaller than that for the ANB angle, while the R&R error for Tau measurement was more than three times greater than that for the ANB angle (p < 0.001). CONCLUSIONS: The results of ANB angle measurements exhibit fewer errors in comparison to Tau angle measurements.

The effects of surgical expansion of the maxillary arch and its consequences for the incisor axis.

PURPOSE: Reduced transverse maxillary dental arch width may be treated either by surgically supported rapid maxillary expansion (SRME) with conservative orthodontic appliances or by means of Le Fort I osteotomy (LFIO). Both are means of transverse maxillary expansion. METHODS: Both surgical methods (SRME and LFIO) were evaluated with regard to the presurgical and postsurgical form of the maxillary dental arch and its consequences for the incisor axis by means of 32 dental casts and cephalometric analysis. RESULTS: In both groups, anterior and posterior dental arch width showed significant changes after surgery, but changes in anterior dental arch width were less significant after LFIO (p = 0.004) than after SRME (p < 0.000; t-test). Cephalometric analysis (OK1/N1) did not show any significant differences between the two surgical methods (p = 0.1266; t-test). Anterior arch length was not reduced after LFIO but significantly reduced after SRME. Thus, the ideal elliptical shape of the dental arch was lost in the SRME group, which may impede esthetic outcome of the maxillary dental arch. CONCLUSION: Le Fort I osteotomy achieving direct transverse expansion should be favored over surgically supported rapid maxillary expansion if transverse expansion does not exceed 7 mm.

Digital Cephalometric Tracings by PRO-CEPH V3 Software for Comparative Analyses of Vertical Dimension in Edentulous Patients.

BACKGROUND: Several methods, some physiological, some radiographical and some merely based on experience are taken upon by the practitioner to get him/her close to VDO in the edentulous patients. No single method can however claim to be the perfect answer. Lateral cephalograms have been a standard mode of determining the vertical dimensions in dentate and edentulous patients since the past. Due to unavoidable manual errors, there are chances of variations in the radiographic method too. Advancement in the digital technology has made recording jaw relations faster, simpler and more precise. AIM: This study compared the vertical dimension of occlusion in edentulous patients recorded by using three different physiological methods with the aid of digital cephalometric tracings using indigenously developed PRO-CEPH V3 software. MATERIALS AND METHODS: For the present study a total of 50 dentulous and 25 edentulous patients were selected through inclusion and exclusion criteria. A lateral cephalometric radiograph was taken for all the 50 dentulous subjects at Maximum Intercuspation (VDO) whereas three lateral cephalometric radiographs were obtained for all edentulous patients at the VDO following three different techniques- the Niswonger's method, Phonetics method and Swallowing threshold method. Cephalometric tracings were carried out using indigenously developed PRO-CEPH V3 software. Linear and angular measurement were made and analysed. CONCLUSION: The indigenously developed software PRO-CEPH V3 is capable of making both the linear and angular measurement and therefore provide with relative credibility information regarding the possible VDO in the edentulous patients through cephalometric radiography.

PREDICATING THE “WITS” APPRAISAL FROM THE ANB ANGLE / 药物分析学报

Objective In order to explore the relationship between the “Wits" appraisal and the ANB angle, and to see how accurately one can predict the “Wits”. Methods Given the ANB, lateral cephalometric radiographs were taken on 50 boys and 50 girls between the ages of 11～13. Results Each subject had no treatment either a Class Ⅰ or Class Ⅱ malocclusion, a good growth pattern. Group Ⅰ , 13 subjects of 100 had ANB≤1.5°, and negative “Wits” appraisal; group Ⅱ , 61 subjects had 5.8°＞ANB＞1.5°, and “Wits” appraisal either positive or negative; group Ⅲ , 26 subjects had ANB angle≥5.8°, and positive “Wits” appraisal. Statistically analysis showed that there was no sig nificant difference in sex (P＞0.05); there was significant correlation between the ANB and “Wits” values in the group Ⅱ and group Ⅲ (P ＜0. 05); there was statistical significance in regression analysis in the group Ⅰ and group Ⅱ (P ＜0. 05). We could predict the “Wits” with 21％ accuracy in group Ⅱ. Conclusion The results indicate that these figures are statistically significant but clinically irrelevant.