Morphological and Dimensional Analysis of the Nasopalatine Canal: Insights from Cone-Beam Computed Tomography Imaging in a Large Cohort.

BACKGROUND The nasopalatine canal (NPC), or incisive canal, is located in the midline of the palate, posterior to the maxillary central incisors. Its anatomy is important in prosthetic dentistry procedures. This study aimed to assess the anatomical morphology of the NPC according to age, sex, and dental status using cone-beam computed tomography (CBCT) in 335 patients. MATERIAL AND METHODS In this retrospective cross-sectional study, a total of 335 patients were recruited and categorized according to sex, age, and dental status. Individual CBCT images were analyzed in the sagittal, coronal, and axial planes. Also, we recorded the dimensions and morphological shape of the NPC and adjacent buccal bone plate (BBP) under standardized conditions. The associations between sex, age group, NPC shapes and types, and presence of central incisors were assessed. A significance level was set at P<0.05. RESULTS Mean labio-palatal and mediolateral measurements of the incisive foramen were 5.13±1.45 mm and 3.21±0.96 mm, whereas the mean diameter of Stenson foramen was 2.57±1.25 mm, and the total length of the NPC was 11.79±2.50 mm. Funnel, Y, and round-shaped canals were the most prevalent shapes of the NPC in sagittal, coronal, and axial planes. BBP was greater in men, with P=0.011, P=0.000, and P=0.001 at BBP1, BBP2, and BBP3, respectively. CONCLUSIONS NPC and BBP parameter values were slightly higher among male patients. NPC parameters increased with older age. The crest width of BBP decreased with older age and after missing maxillary central incisor teeth.

Alveolar bone morphology in patients with palatally-displaced maxillary lateral incisors before and after orthodontic treatment: A cone-beam computed tomography study.

INTRODUCTION: Palatal displacement of maxillary anterior teeth is common in clinical practice. Previous studies have reported that the labial bone around palatally-displaced incisors is thinner than that around normally-placed teeth. Therefore, it is necessary to elucidate alveolar bone changes after alignment to guide orthodontic treatment. In this study, we investigated the alveolar bone changes around palatally-displaced maxillary lateral incisors before and after treatment, and the effects of extraction and age using cone-beam computed tomography. METHODS: In this retrospective study, 55 patients with unilateral palatally-displaced maxillary lateral incisors were included. Three-dimensional alveolar bone changes were measured at three levels (25%, 50% and 75% of the root length) using cone-beam computed tomography. Group comparisons were made between displaced and control teeth, extraction and non-extraction groups, and adult and minor groups. RESULTS: After orthodontic treatment, labiopalatal and palatal alveolar bone widths decreased at all measured levels. Labial alveolar bone width increased significantly at P25, but decreased at P75. Concavity decreased, while tooth-axis angle, tooth length, B-CEJ and P-CEJ increased. Changes in LB and LP at P75, B-CEJ and P-CEJ were statistically significant. After treatment, the tooth-axis angle on the PD side increased by 9.46°. The change in tooth-axis angle on the PD side was significantly smaller, and LB and LP decreased more at P75, in the extraction group. CONCLUSIONS: Compared to the control teeth, alveolar bone thickness and height for the displaced teeth decreased more significantly after treatment. Tooth extraction and age also influenced alveolar bone changes.

Changes in the alveolar bone morphology among different patterns of incisor inclination during the alignment phase in orthodontic treatment without premolar extraction.

OBJECTIVE: The present study investigated bone remodelling in the upper and lower incisor regions depending on the inclination pattern during the alignment phase of orthodontic treatment (OT). MATERIALS AND METHODS: This prospective clinical study included 71 patients undergoing OT without premolar extraction. Cone beam computed tomography scans were taken before and after the alignment phase and the changes in the inclination, alveolar bone height (ABH) and bone thickness (BT) at levels 2, 3, 4, 6, 8 and 9 mm starting from the cementoenamel junction (CEJ) were determined. RESULTS: Teeth were divided into 'Retroinclination' (lingual crown inclination <0°), 'Proclination-low' (buccal crown inclination between 0° and 5°), or 'Proclination-high' (buccal crown inclination >5°). The alignment phase of OT resulted in ABH loss. The highest ABH loss in the maxilla was observed on the buccal side in the 'Proclination-high' and was 0.71 mm. ABH loss by 1.1 mm was observed in the mandible on the lingual side in the 'Retroinclination' group. The most significant changes in BT by up to 2 mm were observed at levels 6, 8 and 9 mm and these changes exhibited a moderate to strong correlation with the alterations in the inclination of individual incisors. At levels 2, 3 and 4 mm, the highest decrease in BT by up to 0.83 mm was observed on the palatal side of upper incisors in the 'Proclination-high' group. CONCLUSION: The direction and amount of tooth inclination partially determine changes in the bone parameters during the alignment phase.

Assessment of gingival translucency at the mandibular incisors with two different probing systems. A cross sectional study.

OBJECTIVES: Increasing evidence indicates that the thickness of periodontal soft tissues plays an important role in various clinical scenarios, thus pointing to the need of further clinical research in this area. Aim of the present study was to assess gingival thickness at the mandibular incisors by translucency judgement with two different probes and to validate if these methods are comparable and applicable as diagnostic tools. MATERIALS AND METHODS: A total of 200 participants were included; gingival tissue thickness was measured by judging probe translucency at both central mandibular incisors, mid-facially on the buccal aspect of each tooth using a standard periodontal probe and a set of color-coded probe, each with a different color at the tip, i.e. Colorvue Biotype Probe (CBP). Frequencies and relative frequencies were calculated for probe visibility. Agreement between the standard periodontal probe and the CBP was evaluated via the kappa statistic. RESULTS: When the periodontal probe was visible, the frequency of CBP being visible was very high. Kappa statistic for the agreement between the standard periodontal probe and the CBP was 0.198 (71.5% agreement; p-value < 0.001) for tooth 41 and 0.311 (74.0% agreement; p-value < 0.001) for tooth 31, indicating a positive association of the two methods. CONCLUSIONS: An agreement that reached 74% was estimated between the standard periodontal probe and the color-coded probe at central mandibular incisors.  CLINICAL RELEVANCE: In the context of the present study, the two methods of evaluating gingival thickness seem to produce comparable measurements with a substantial agreement. However, in the 1/4 of the cases, the visibility of the color-coded probe could not assist in the categorization of the gingival phenotype.

Comparison between direct and indirect "digital image" dental visual shade matching considering the effect of clinical experience and gender.

INTRODUCTION: Shade matching is an essential procedure to obtain an esthetic prosthesis. The Direct Visual Shade Matching (DSM) method using shade guides is the most used method by dentists. However, The Indirect Visual Digital Shade Matching (ISM) method based on digital imaging is concerned to be reliable and useful in determining shade matching in dental practice. Several factors such as method, clinical experience, and gender can affect the success of shade matching. AIM OF THE STUDY: This study aimed to compare these two methods and evaluate the effect of experience and gender on the results. MATERIALS AND METHODS: Three volunteers' maxillary central incisor teeth were evaluated using (DSM) and (ISM) methods by 87 examiners (42 males, 45 females). These examiners were further divided into three groups based on their clinical experience: Undergraduate Preclinical Dental Students (UPDS) with 31 examiners, Undergraduate Clinical Dental Students (UCDS) with 34 examiners, and Postgraduate Dental Students from the Department of Prosthodontics (PDS) with 22 examiners. The spectrophotometer device results of three teeth were considered as a reference for shade matching. Statistical analyses of the data were performed using Kruskal-Wallis, Mann-Whitney U, and Chi-square tests. RESULTS: No significant difference was found between indirect and direct methods according to Perfect Matches (p > 0.05). However, according to Shade Matching Deviation Score (SMDS) values a statistically significant difference was found between the two methods where the best result was obtained with the ISM method (p < 0.05). There was a significant difference between the PDS group and the other two groups in terms of clinical experience (p < 0.05). There was no significant difference between gender groups (p > 0.05). CONCLUSION: Digital images, captured under standardized lighting conditions, may serve as a reliable alternative method for direct shade matching. The (ISM) method requires a camera, related accessories, and computer skills. However, as these tools are commonly available nowadays, the focus for practitioners should be on effectively learning and applying these tools to achieve the best results. While clinical experience plays a significant role in the shade matching process, gender does not appear to have a substantial influence. CLINICAL SIGNIFICANCE: This study found no significant differences between the (DSM) and (ISM) methods, leaving the clinical relevance of this method open to debate. However, the ISM method yielded superior responses. Despite requiring specialized tools, conditions, and training, the widespread use of cameras and computers in modern clinics makes the necessary equipment and software readily available. This method enhances clinician-technician communication, potentially improving prosthesis esthetics and patient satisfaction, especially for less experienced clinicians or those with color deficiencies. Further research is crucial to determine its clinical significance.

Two- and three-dimensional symmetry of maxillary incisors: A clinical study.

OBJECTIVE: To assess the 2D and 3D natural symmetry of the maxillary incisors. MATERIALS AND METHODS: Maxillary alginate impressions were taken of 59 young adult volunteers. Gender, orthodontic treatment history, and dominant hand were collected. For 2D analysis, a digital caliper was used for measurements on maxillary casts. For 3D analysis, the casts were scanned using a lab scanner, and the labial surface symmetry of contralateral incisors was evaluated. Mann-Whitney tests and Student's t-test were performed, α = 0.05. RESULTS: Results indicated a lack of identical lengths among contralateral central or lateral incisors, with minimal occurrences of identical width measurements. 68% of central incisors and 73% of lateral incisors showed differences in length exceeding 0.2 mm. Central incisors showed more similarities than lateral incisors in width, with 61% central incisors and 47% lateral incisors having differences under 0.2 mm. The differences between highly asymmetrical contralateral teeth are situated at the transitional lines. The influence of sexual dimorphism, orthodontic factors, and the dominant hand on incisors' symmetry was not statistically significant. CONCLUSIONS: 2D and 3D symmetry of the natural maxillary incisors are rare. 3D symmetry remains consistent across orthodontic treatment status, gender, and dominant hand, suggesting its independence from such parameters. CLINICAL SIGNIFICANCE: To achieve a natural and aesthetic smile rehabilitation, the symmetry of the maxillary incisors must be well understood. In our study, 2D and 3D symmetry of the maxillary incisors occurred rarely, but central incisors showed more similarities than lateral incisors in width, with differences under 0.2 mm. On the other hand, differences between highly asymmetrical contralateral teeth are situated at the transitional lines. These conclusions should be included in further computer-assisted three-dimensional smile designs.

Cone beam computed tomography assessment of maxillary anterior teeth cervix dimensions in healthy adults for optimal anatomic healing abutments.

OBJECTIVES: The abutments produced with circular symmetry failed to accurately replicate the natural teeth's cervical shapes. The purpose of this study was to measure cervical cross-sections of maxillary anterior teeth using cone beam computed tomography (CBCT) images to design anatomic healing abutments. MATERIALS AND METHODS: CBCT data of 61 patients were analyzed using Ez3D Plus software. Measurements were taken at the cemento-enamel junction (CEJ) and 1 mm coronal to CEJ for maxillary central incisors, lateral incisors, and canines. Various parameters, including area, perimeter, and eight line segments in the distal (a), disto-palatal (b), palatal (c), mesio-palatal (d), mesial (e), mesio-labial (f), labial (g), and disto-labial (h) directions, were used to describe dental neck contours. The ratios (f/b and h/d) were analyzed, and differences based on sex and dental arch morphology were explored. RESULTS: Significant differences were found in area and perimeter between males and females, but not in f/b and h/d ratios. Differences in the f/b ratio were observed among dental arch morphologies for maxillary central incisors, lateral incisors, and canines. CONCLUSIONS: CBCT measurements of cervical cross-sections provide more accurate data for designing anatomic healing abutments. The fabrication of anatomical healing abutments needs to consider the influence of gender on cervical size and to explore the potential effect of arch shape on cervical morphology. CLINICAL SIGNIFICANCE: The novel method provides detailed measurements for the description of dental cervical contours for patients with bilateral homonymous teeth missing. The measurements of this study could be utilized to design more accurate anatomic healing abutments to create desired morphology of peri-implant soft tissue.

Clinical evaluation of tooth angle and peripheral bone thickness considering sex and age for implant placement in the maxillary anterior region.

STATEMENT OF PROBLEM: Consideration of the thickness of alveolar bone on both the palatal and labial sides and the inclination angle of teeth is important for immediate implant placement in the maxillary anterior region. However, comprehensive research exploring how sex and age influence the thickness of bone and tooth angle in the maxillary anterior region is lacking. PURPOSE: The purpose of this clinical study was to investigate the effect of sex and age on the thickness of labial and palatal bone and on the tooth inclination angle of maxillary central and lateral incisors using cone beam computed tomography (CBCT) images in an Asian population. MATERIAL AND METHODS: The labial and palatal bone thickness and the inclination angle of maxillary central and lateral incisors were measured from the CBCT images of 149 participants aged between 20 and 65 years. The correlation between the angles of the maxillary central and lateral incisors and sex and age on the tooth angles and thicknesses of labial and palatal bone was determined statistically. RESULTS: A high correlation (R=0.73) was found between the angle of maxillary central and lateral incisors. Men had higher angles of the maxillary central and lateral incisors and thicker palatal bone at the middle and root of the teeth compared with women. In both sexes, the angle and palatal bone thickness of maxillary central incisors were significantly higher than those of maxillary lateral incisors. The angle of both maxillary central and lateral incisors decreased gradually with age, with a difference in angle of over 10 degrees. CONCLUSIONS: The study revealed that women exhibited relatively thinner palatal bone compared with men. Additionally, participants aged between 40 and 65 years exhibited significantly thicker palatal bone compared with younger age groups, potentially providing a larger site for implant placement. Furthermore, tooth angle gradually decreases with age in the maxillary anterior region.

The dimensions of preformed nickel-titanium archwires measured at the bracket positions corresponding to the central incisor, canine, and first molar.

INTRODUCTION: Variation in the thickness of commercially available preformed rectangular archwires at the bracket positions has not been thoroughly studied. Therefore, this study measured the edgewise (height) and flatwise (width) dimensions of preformed rectangular nickel-titanium (NiTi) archwires at bracket positions corresponding to the central incisor, canine, and first molar and compared them among bracket positions. METHODS: Sixty types of preformed rectangular NiTi mandibular archwires indicated as 0.019 × 0.025-in were obtained from 14 manufacturers. The height and width dimensions of archwires were measured at 4 points (3 bracket positions corresponding to the central incisor, canine, and first molar, and 1 terminal end) of each side of each archwire using a micrometer and compared with the indicated dimensions using 1-sample t tests. Furthermore, the measured dimensions were compared among the 3 bracket positions using a 1-way analysis of variance and Bonferroni post-hoc test. RESULTS: The measured dimensions were significantly smaller than the indicated dimensions for all points except the central incisor point for height and significantly smaller than the indicated dimensions for all points for width. Comparisons among points showed that for height, the central incisor point was significantly larger than the first molar and terminal points. However, no significant differences were found for width at any point. CONCLUSIONS: The measured dimensions of preformed NiTi archwires at the bracket positions were generally smaller than the indicated dimensions, with variations observed not only among products but also among manufacturers.

The usefulness of ultrasonography as a dynamic measurement system for visualizing root canal working length: an in vivo study.

OBJECTIVE: Although apex locators are generally effective tools for determining root canal working length, they may produce inaccurate results in some cases. The present study aimed to evaluate the efficacy of ultrasonography as an alternative method for measuring root canal length. MATERIALS AND METHODS: Forty-seven anterior teeth with apical lesions were selected for the study. Initially, an electronic apex locator was used to measure the working length. Subsequently, ultrasonography was employed to visualize the root apex and determine the working length. During ultrasound imaging, a K-file No. 15 was inserted into the root canal until its tip was visible on the ultrasound monitor. Measurements obtained from both methods were compared using an independent sample t-test. Correlations were assessed with the Pearson correlation coefficient, and agreement was determined using the Bland‒Altman plot. RESULTS: The mean working canal length was 19.9 mm for the apex locator and 20.6 mm for the ultrasonography-guided method. No significant differences were observed between the data obtained using the apex locator method and the data obtained using the ultrasonography guidance method. Furthermore, a high level of agreement was identified between the two techniques. CONCLUSION: Ultrasonography can be used to visualize the apex effectively and determine canal length, especially when canal length determination is uncertain for various reasons.

Micro-XCT analysis of anatomical features and dimensions of the incisive canal: implications for dental implant treatment in the anterior maxilla.

BACKGROUND: This study used micro-focus X-ray Computed Tomography (micro-XCT) to examine the anatomical differences and dimensions of the maxillary incisive canal (MIC) in a South African population. The accurate imaging yielded dependable results that support earlier research and enhance anterior maxilla surgery planning. Furthermore, these anatomical features are compared between various racial and gender groupings in the study. METHODS: Using a micro-XCT scanner, 108 human cadaver skulls from the Pretoria Bone Collection were scanned and included in the study. Advanced volume rendering software was employed for measuring the MIC length, diameter, shape, and the buccal bone wall measurements in relation to the MIC. RESULTS: Significant anatomical variation in the size and shape of the MIC was identified in the population, with variations seen between racial and gender groups. The incisive foramen (ICO) mean diameter was 6.61 mm, and the MIC length varied from 4.96 to 20.10 mm. There were significant differences in the buccal alveolar bone height between different ethnic groups and gender. Regarding morphological patterns in coronal and sagittal views, single canals were more common in the black population while Y-shaped canals were more common in the white population. The study also introduced a new metric by measuring the mean distances between teeth #11 and #21 and the ICO (1.83 mm and 1.88 mm respectively). CONCLUSIONS: The complex anatomical differences of the MIC in a South African population were clarified. Clinicians should be aware of tooth sockets in near proximity to the MIC and perform accurate preoperative assessment using sophisticated 3-D imaging and preferable guided implant placement in the anterior maxilla.

A comparative study of the application of three digital imaging techniques to assess the thickness of the palatal mucosa of the maxillary anterior teeth.

BACKGROUND: This study highlights the need for precise and efficient methods to measure palatal mucosal thickness in the maxillary anterior teeth, particularly for soft tissue augmentation in the aesthetic zone. The research evaluates three digital imaging techniques, suggesting that Cone Beam Computed Tomography (CBCT) combined with intraoral scanners (IOS) is a promising approach for reliable clinical assessment. METHODS: Ten volunteers with healthy periodontium were selected, and three methods were employed: CBCT-based indirect gingival imaging, modified soft tissue CBCT (ST-CBCT), and CBCT combined with IOS. Measurements of palatal mucosal thickness were taken at multiple points along the palatal gingival margin. Statistical analysis included Bland-Altman plots for method agreement and intraclass Correlation Coefficient (ICC) analysis for reliability. All measurements were standardized, repeated for consistency, and accurate to 0.01 mm to ensure reliability. RESULTS: The Bland-Altman plots showed that less than 5% of the points for palatal mucosal thickness differences measured by the gingival indirect radiographic method, modified ST-CBCT, and CBCT combined with IOS were located outside the 95% limits of agreement (LoA). The mean value of the differences was within 0.2 mm, indicating good clinical agreement among the three methods. The inter- and intra-study ICC values for palatal mucosal thickness measurements of the maxillary anterior teeth using the three CBCT methods were greater than 0.75 (P < 0.001), demonstrating reproducibility. CONCLUSIONS: Based on the evaluation of three digital imaging techniques, this study indicates that the combination of CBCT with IOS is a feasible method for measuring palatal mucosal thickness in the maxillary anterior teeth and demonstrates good reproducibility.

Credibility of Pont's index in Egyptian population.

BACKGROUND: Many indices have been suggested to help orthodontists in predicting the ideal dental arch width. One of these was Pont's index which was established by Pont. He suggested equations to predict the ideal maxillary dental arch width (interpremolar and intermolar) from the combined mesiodistal width of the maxillary incisors. This study aimed to test the applicability of Pont's index as an orthodontic diagnostic tool in Egyptian population and to compare the results with those obtained from studies of different ethnic subjects. METHODS: This study was performed using dental casts of 184 Egyptian individuals (82 males and 102 females; age range, 19-24 years). The casts were divided into 46 casts with normal occlusion, 46 casts with class I, 46 casts with class II and 46 casts with class III malocclusion, according to Angle's classification. Alginate impressions were taken for all patients and poured immediately using dental plaster. The real models were transformed into digital models using three-dimensional laser scanner to allow digital model analysis. Predicted arch widths were calculated using Pont's equations. The predicted values were compared to the measured values. RESULTS: Intra class correlation coefficient (ICC) (absolute agreement) between measured and predicted arch widths was determined. Poor absolute agreement was found between measured arch width values and the corresponding values calculated according to Pont's index. CONCLUSION: According to the results of this study, Pont's index is not a reliable method for predicting the ideal dental arch widths in Egyptian populations.

Network analysis of three-dimensional hard-soft tissue relationships in the lower 1/3 of the face: skeletal Class I-normodivergent malocclusion versus Class II-hyperdivergent malocclusion.

BACKGROUND: The determining effect of facial hard tissues on soft tissue morphology in orthodontic patients has yet to be explained. The aim of this study was to clarify the hard-soft tissue relationships of the lower 1/3 of the face in skeletal Class II-hyperdivergent patients compared with those in Class I-normodivergent patients using network analysis. METHODS: Fifty-two adult patients (42 females, 10 males; age, 26.58 ± 5.80 years) were divided into two groups: Group 1, 25 subjects, skeletal Class I normodivergent pattern with straight profile; Group 2, 27 subjects, skeletal Class II hyperdivergent pattern with convex profile. Pretreatment cone-beam computed tomography and three-dimensional facial scans were taken and superimposed, on which landmarks were identified manually, and their coordinate values were used for network analysis. RESULTS: (1) In sagittal direction, Group 2 correlations were generally weaker than Group 1. In both the vertical and sagittal directions of Group 1, the most influential hard tissue landmarks to soft tissues were located between the level of cemento-enamel junction of upper teeth and root apex of lower teeth. In Group 2, the hard tissue landmarks with the greatest influence in vertical direction were distributed more forward and downward than in Group 1. (2) In Group 1, all the correlations for vertical-hard tissue to sagittal-soft tissue position and sagittal-hard tissue to vertical-soft tissue position were positive. However, Group 2 correlations between vertical-hard tissue and sagittal-soft tissue positions were mostly negative. Between sagittal-hard tissue and vertical-soft tissue positions, Group 2 correlations were negative for mandible, and were positive for maxilla and teeth. CONCLUSION: Compared with Class I normodivergent patients with straight profile, Class II hyperdivergent patients with convex profile had more variations in soft tissue morphology in sagittal direction. In vertical direction, the most relevant hard tissue landmarks on which soft tissue predictions should be based were distributed more forward and downward in Class II hyperdivergent patients with convex profile. Class II hyperdivergent pattern with convex profile was an imbalanced phenotype concerning sagittal and vertical positions of maxillofacial hard and soft tissues.

The relationship of anterior occlusion and skeletal variables with the frontal sinus index: An analytical cross-sectional study.

OBJECTIVE: To determine the relationship of anterior occlusion and skeletal variables with the frontal sinus index. METHODS: The retrospective, analytical, cross-sectional, study was conducted from July to November 2020 at Dr Ishratul- Ebad Khan Institute of Oral Health Sciences and Dow Dental College, Dow University of Health Sciences, Karachi, and comprised data from 2015 to 2018 related to pre-treatment lateral cephalograms for determining frontal sinus index and other cephalometric variables. The dental casts were observed for incisor classification. Patients with Class I incisors formed the comparison group, while the rest comprised 5 malocclusion groups. The frontal sinus was traced, and the sinus index was calculated. Data was analysed using STATA 15 and R 3.5.1. RESULTS: Of the 240 subjects, there were 40(16.66%) in each of the 6 groups; 155(64.6%) females and 85(35.4%) males. The mean age of the sample was 21.33±3.52 years (range: 16-29 years). The mean sinus index was higher in all malocclusion groups than the comparison group, but it was significantly higher only in Class II division 2 and anterior open bite groups (p<0.05). The only exception to the trend was Class II division 1 with and without contact in which the value was lower (p>0.05). The anterior cranial base length, sella-nasion mandibular plane angle, and upper incisor palatal plane angle significantly affected the frontal sinus index (p<0.05). CONCLUSIONS: The frontal sinus index could be considered an indicator of harmonious anterior occlusion.

Root canal configuration of human permanent anterior teeth: A cross-sectional study using cone-beam computed tomography in the Pakistani population.

Objectives: To analyse and document internal root morphological variations in permanent anterior teeth using conebeam computed tomography. METHODS: The cross-sectional, retrospective study was conducted from January 21 to June 19, 2021, at Jinnah Magnetic Resonance Imaging and Body Scan, and comprised data from July to December 2020 related to all the patients who had been referred to the centre for dental cone-beam computed tomography scan. The scans were evaluated at the Radiology Department of the School of Dentistry at Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan. The morphology of the roots and root canals in all permanent anterior teeth was examined. Root canal configuration was categorised using Vertucci's classification. Data was analysed using SPSS 20. RESULTS: Of the 211 patients, 116(55%) were females and 95(45%) were males. The overall mean age was 39.9±1.02 years (range: 15-65 years). All the permanent anterior teeth exhibited a single root, with the exception 2(0.9%) mandibular right and 4(1.9%) left canines which had double roots. Type I root canals were observed in all 211 (100%) maxillary right central incisors, maxillary left central incisors and maxillary left canines. Among maxillary right canines, 208(98.6%) had type-I root canals, and the corresponding value for maxillary right lateral incisors was 209(99.1%), and for maxillary left lateral incisors, the value was 210(99.5%). Root canal polymorphism had no significant association with gender (p>0.05). CONCLUSIONS: The presence of type-I root canal was common in permanent anterior teeth, and there was significant association of root canal polymorphism with gender.

Evaluation of Mesiodistal Angulation of Maxillary Anterior Teeth in Incisal View Using Manual and Digital Methods: An In Vivo Study.

AIM: The aim of the present research was to assess the mesiodistal angulation of the maxillary anterior teeth utilizing Image J computer software, a Profile projector, and a Custom-made jig. MATERIALS AND METHODS: A total of 34 subjects (17 males and 17 females) were chosen from a group of 18-30 years old with bilateral Angle Class I molars and canine relationships. One manual approach (Custom-made jig) and two digital methods (J computer software, a Profile projector) were used to record the mesiodistal angulation in incisal view. The individuals had alginate impressions made, and a facebow was used to capture the maxilla's spatial relationship with the cranium. The articulated cast with the help of mounting ring moved to the specially customized jig, then the angulations was measured in the incisal view after the casts were placed in a semi-adjustable articulator. Data were recorded and statistically analyzed. RESULTS: The mesiodistal angulation in the incisal view via three methods between the 17 males and 17 females has statistically significant different. Although the mesiodistal angulation for maxillary lateral incisor and canine did not show any statistically significant difference, the maximum and minimum values obtained were always greater in males in comparison with the females. This indicates that the positions of six maxillary anterior teeth in the males resulted in the creation of upward sweep of incisal edges of central and lateral incisors which was also referred to as "smiling line" producing masculine surface anatomy more squared and vigorous while feminine surface anatomy being more rounded, soft, and pleasant. There was no statistically significant difference between the right and left sides, indicating bilateral arch symmetry and the symmetrical place of the right teeth compared with the left side's corresponding teeth. CONCLUSION: On conclusion, according to the current study's findings, all three approaches can measure the mesiodistal angulations of maxillary anterior teeth in incisal view with clinically acceptable accuracy. The digital methods, which included using the Image J computer software and the profile projector, achieved more accurate results than the manual method. CLINICAL SIGNIFICANCE: The outcomes of this study's mesiodistal angulations can be used as a reference for placing teeth in both fully and partially edentulous conditions. This study contributes to a better understanding of the importance of achieving the ideal occlusion in the Indian population by placing the maxillary anterior teeth at the proper mesiodistal angulation. How to cite this article: Shadaksharappa SH, Lahiri B, Kamath AG, et al. Evaluation of Mesiodistal Angulation of Maxillary Anterior Teeth in Incisal View Using Manual and Digital Methods: An In Vivo Study. J Contemp Dent Pract 2024;25(4):320-325.

Adolescents and Children Age Estimation Using Machine Learning Based on Pulp and Tooth Volumes on CBCT Images.

OBJECTIVES: To estimate adolescents and children age using stepwise regression and machine learning methods based on the pulp and tooth volumes of the left maxillary central incisor and cuspid on cone beam computed tomography (CBCT) images, and to compare and analyze the estimation results. METHODS: A total of 498 Shanghai Han adolescents and children CBCT images of the oral and maxillofacial regions were collected. The pulp and tooth volumes of the left maxillary central incisor and cuspid were measured and calculated. Three machine learning algorithms (K-nearest neighbor, ridge regression, and decision tree) and stepwise regression were used to establish four age estimation models. The coefficient of determination, mean error, root mean square error, mean square error and mean absolute error were computed and compared. A correlation heatmap was drawn to visualize and the monotonic relationship between parameters was visually analyzed. RESULTS: The K-nearest neighbor model (R2=0.779) and the ridge regression model (R2=0.729) outperformed stepwise regression (R2=0.617), while the decision tree model (R2=0.494) showed poor fitting. The correlation heatmap demonstrated a monotonically negative correlation between age and the parameters including pulp volume, the ratio of pulp volume to hard tissue volume, and the ratio of pulp volume to tooth volume. CONCLUSIONS: Pulp volume and pulp volume proportion are closely related to age. The application of CBCT-based machine learning methods can provide more accurate age estimation results, which lays a foundation for further CBCT-based deep learning dental age estimation research.

Comparing Skin Tones to Shades of Upper Anterior Teeth: An Observational Study among Nigerian Adults.

BACKGROUND: Skin tones may be predictive of anterior tooth shade. An analysis of the relationship of skin tone to anterior tooth shade within a population may facilitate the prescription of complete dentures with optimal esthetics and realism. AIM: This study aimed to assess the relationship between skin tones and shades of upper anterior teeth among a diverse Nigerian adult population. METHODS: The study was conducted between February and December 2022 among consecutive healthy adults recruited from dental clinics of five teaching hospitals in four cities located across four geopolitical zones of Nigeria. Skin tones were recorded using the National Immigration Service (NIS) Skin Color scale. The Vitapan Classic® shade guide was used to record the tooth shade of the upper central incisors and canines. Bivariate and multivariate tests of associations were performed, and predictive probabilities were developed. RESULTS: A total of 1070 adults with a mean age of 30.8 ± 10 years participated in the study. NIS skin tones 6 (29.8%) and 5 (27.7%) were the most common, while hues A (48.7% in incisors and 48.4 % in canines) and B (41.1% in incisors and 40.1% in canines) were predominant. The values of the incisors and canines were positively related to skin tone (P = 0.001) and age (P = 0.001 for incisors and P = 0.003 for canines). Hue was also significantly associated with skin tone for canines (P = 0.01) and gender (P = 0.001). Regression models showed increasingly darker skin tones were positively related to duller values for incisor teeth (ß = 0.173, OR =1.19, P < 0.001). The values for canines were more likely to be >2 (ß = 0.118, OR =1.12, P = 0.01), but without significant positive relationship to increasingly darker skin tones (ß = -0.99, OR =0.91, P = 0.22). CONCLUSION: Skin tones were associated with upper anterior tooth shade. There was a positive relationship between skin tones and the shades of upper anterior teeth. Skin tones could guide the clinician in shade selection during complete denture prescriptions.

Cone-Beam Computed Tomographic Study of the Internal Anatomy of Lower Anterior Teeth.

Background A thorough knowledge of the root and canal morphology and their possible variations are essential for successful endodontic treatment. Methods like staining and clearing techniques, cross sectional method can provide precise information on root canal systems, however, these methods are invasive. Cone-beam computed tomography (CBCT) is the 3-dimensional scans of the maxillofacial skeleton that best visualizes canal morphology and helps in identifying additional canals and roots in vivo. Objective To investigate the root canal configuration of mandibular anterior teeth using Conebeam computed tomography. Method A total of 2910 CBCT images, comprising 970 central incisors, lateral incisors, and canines each from 485 patients were assessed. The following assessments were made: (1) The number of roots and root canals (2) Canal configuration according to Vertucci's classification (3) Bilateral occurrences for variations. Also, the gender and age of patients were noted. Result The study revealed mandibular anterior teeth predominantly had 1 root with Type I (79.79%, 77.11%, 91.34%) canal configuration followed by type III (20.2%, 22.67%, 5.15%) in central, lateral and canine respectively. Almost 90% incisors had symmetry in the canal configurations. No statistical correlation was found between the gender and root canal configurations. Type III canal configurations in canines were present more in elder age group. Conclusion Clinicians must be aware that each tooth may display a different number of roots and types of canal configurations. During endodontic treatment, presuming lower anterior teeth with single root and single canal may lead to missed canals and consequently, treatment failure.