Upper Central Incisor Research Articles

Precision in dentistry: how PLA 3D printing settings influence model accuracy.

Advancements in computer-aided design and manufacturing (CAD/CAM), such as intraoral scanners, digital treatment planning, and 3D printers, offer digital alternatives to conventional orthodontics. For transforming digital data into atraditional model, precise 3D printing technologies are necessary. With numerous settings available on each 3D printer, selecting the most precise one is challenging. Therefore, the impact of layer height, printing temperature, print speed, and infill density on the accuracy of dental models was analyzed in this study. A3D file of aright upper central incisor was designed and printed 275 times in total with different settings for temperature, layer height, print speed, and infill density by using polylactic acid (PLA) filament on an industrial 3D printer. After scanning the models, root mean square error was calculated for analysis of precision. For each group, R2 value was calculated and linear regression as well as an ANOVA was performed for the factors influencing accuracy. Printing temperature as well as layer height had statistically significant impacts on printing 3D tooth models (p < 0.05). R2 values of 0.43 for printing temperature as well as of 0.11 for layer height were detected. The infill density as well as the print speed had no statistically significant impacts on accuracy (p > 0.05). This study confirms that choosing the correct printing temperature and layer height for printing dental models with PLA is important for obtaining good accuracy, whereas print speed and infill density have less of an impact.

Radiographic characteristics and chronological patterns of transient apical breakdown (TAB) in luxated permanent teeth: A retrospective observational study.

To describe radiographic features, clinical signs and symptoms, and chronological patterns of post-traumatic transient apical breakdown (TAB) in luxated permanent teeth. Records from 56 patients treated at the Dental Trauma Clinic of the School of Dentistry of the Federal University of Minas Gerais from 1993 to 2024 were accessed to collect demographic, clinical, and imaging features of 89 teeth that presented with radiographic signs of TAB after traumatic dental injury (TDI). Kaplan-Meier curves were built to illustrate the time elapsed between trauma until TAB onset and resolution for the whole sample and for each one of the TAB patterns. A Cox regression was used to explore the effect of clinical covariates in both events. Patients' mean age at the time of trauma was 17.7 ± 6.6years (range 9.1 to 39.7years), with most being male (59.6%). All included teeth were mature at the time of trauma (Moorrees stage 6). Upper central incisors (66.3%) were predominant and mostly suffered extrusions (40.4%) or lateral luxations (32.6%). TAB was observed as an expansion of the periodontal ligament associated with a "V-shaped" widening of the apical foramen together with apical root resorption in 45 teeth (50.6%). Expansion of the periodontal ligament associated with "V-shaped widening of the apical foramen only was observed in 32 teeth (36%), and 12 teeth (13.5%) showed expansion of the periodontal ligament associated with apical root resorption only. The overall median time for TAB onset was 3.2months (range, 26days to 8months), being significantly lower for pattern 2 (1.8months) when compared to TAB pattern 1 and 3 (3.4, and 3.9months) respectively (Logrank test p values < 0.001 for both comparisons). The overall median time for TAB regression was 9.1months (range, 4.8 to 34.8months) after trauma. Again, TAB pattern 2 presented lower periods when compared to TAB pattern 1 and 3 (Logrank test p values < 0.001 and 0.013, respectively). Color changes were not frequent neither at the time of TAB onset nor at the time of TAB resolution. However, while most teeth (53.3%) did not respond to pulp sensibility tests at the time of TAB onset, this proportion decreased to 17.6% by the time of TAB resolution. TAB was mainly diagnosed within four months after luxation of mature teeth, most of them being resolved within the 1-year of follow-up. The most frequent TAB pattern was an expansion of the PDL associated with a "V-shaped" widening of the apical foramen together with external apical root resorption. These findings represent an important contribution for treatment decision-making during the follow-up of luxated permanent teeth.

Intra-maxillary Tooth Width Ratios and Mesiodistal Crown Dimensions of the Permanent Dentition in a Tanzanian Population

Aim: The present study aimed to establish the mesiodistal crown dimension and intra-maxillary tooth width ratios of permanent teeth in a Tanzanian population. Methods: A cross-sectional study was conducted at Muhimbili University Dental Clinic involving 204 orthodontic study models with normal intra-arch occlusion. The mesiodistal width of all the permanent teeth, excluding the second and third molars, was measured using a digital Vernier caliper. Data were analyzed using SPSS 25.0. Tooth width means comparison between sexes and sides was performed using an independent t-test with the significance level set at P&lt;0.05. Intra-arch tooth width ratios, correlation of variance, and mesiodistal tooth width means were calculated and presented in descriptive statistic tables. Results: The widest tooth was the first lower molar (11.55 mm), followed by the upper first molar (10.53 mm) and upper central incisor (9.22 mm). The smallest teeth were the central incisors in the lower jaw (5.67 mm) and the second premolar in the upper jaw (7.12 mm). Males had statistically wider teeth than females in all teeth except the second premolars and upper lateral incisor (P&lt;0.05). The proportions of the upper laterals to upper central incisors were 80.5% and 81.3% in males and females, respectively. Furthermore, the ratio of the upper first premolar to that of the upper canine was 96.3% in females and 93.6% in males. Conclusion: Odontometrics data for the Tanzanian population was determined. The derived measurements were relatively higher compared to those reported in most other populations.

TRAUMATISMOS DENTAIS NA INFÂNCIA E SUAS IMPLICAÇÕES NA POLPA: REVISÃO DE LITERATURA

Childhood dental trauma is common, especially in the 2-7 age group, and affects the upper central incisors more due to their exposure in impact situations. When the trauma involves the dental pulp, the treatment is to preserve the vitality of the tooth, with pulp capping and pulpotomy procedures being the most recommended. Currently, there has been a shift from invasive practices to conservative techniques in order to minimize long-term damage and improve the child's prognosis. The International Association of Dental Traumatology (IADT) guidelines contribute to this conservative approach, affirming the importance of immediate treatment and follow-up to avoid complications. The objective of this study is to demonstrate the implications of dental trauma in childhood, as well as how the pulp reacts to trauma. This literature review is based on articles published between 2014 and 2024, searched in the Scielo, Pubmed, Google Scholar and Periódico Capes databases. It was possible to conclude that, when subjected to trauma, the affected tooth may present some pulp responses, with pulp necrosis was the most frequent alteration.

Quantitative Evaluation of Enamel Thickness in Maxillary Central Incisors in Different Age Groups Utilizing Cone Beam Computed Tomography a Retrospective Analysis.

Background/Objectives: The presence of enamel on the tooth surface is crucial for the long-term success of minimally invasive adhesive restorations such as dental veneers. Our study aims to evaluate the enamel thickness in the incisal, middle, and cervical portions of the labial surface of the upper central incisors using cone beam computed tomography (CBCT). This imaging method provides detailed and accurate three-dimensional images with a low radiation dose, allowing an accurate assessment of enamel thickness. The analysis aims to identify variations in enamel thickness depending on the age and different levels of the labial tooth surface. Methods: 800 CBCT scans performed for diagnostic or therapeutic purposes on patients aged 18-60 years were analyzed. The data were gathered from the imaging archives of private practitioners from Targu Mures and the "George Emil Palade" University of Medicine, Pharmacy, Science, and Technology of Targu Mures. Enamel thickness measurements were conducted using the OnDemand3D Communicator CBCT evaluation program, with subsequent statistical analysis performed using GraphPad Instat Prism software. Results: Results showed significant variation in enamel thickness between the incisal, middle, and cervical segments of the labial surface of the upper central incisors. A decrease in enamel thickness with age has been observed. In patients aged 18-40, mean values of enamel thickness 1 mm and 3 mm above the cementoenamel junction (CEJ) were 0.48 ± 0.092, respectively, 0.819 ± 0.158. In patients over 40, the mean values were 0.454 ± 0.116 and 0.751 ± 0.067 at 1 mm, respectively, 3 mm above the CEJ. Statistically significant differences were found between the two age groups at 1 mm and 3 mm above the CEJ, with p < 0.0001 and p = 0.0214. Conclusions: A statistically significant decrease can be observed in enamel thickness in almost the entire labial surface of the upper central incisors with aging. The varied thickness of the enamel at different tooth levels requires individualized planning for each patient to maximize the long-term aesthetic and functional results.

A New Approach for Analyzing Root Development in Autogenous Tooth Transplants Using Computed Tomography.

The aim of this study was to evaluate root development in autotransplanted teeth using cone-beam computed tomography (CBCT) images. Twelve premolars with incomplete root formation, which were selected to replace prematurely lost upper central incisors, were analyzed by CBCT on two different occasions. The first CBCT examination (T1) was conducted before tooth autotransplantation. The second CBCT examination (T2) was performed over a follow-up period of at least 12 months and < 5 years. Three previously calibrated evaluators assessed root development. The positions of the tomographic planes were standardized. The mean root length in sagittal and coronal tomographic sections was used to validate the root length at T1 and T2. Longitudinal root development of the transplanted tooth was determined by calculating the difference in root length between T2 and T1. The intraclass correlation coefficient (ICC), paired t-test, and Pearson test were applied, with significance set at 5%. The mean time elapsed between T1 and T2 was 962 days/2.6 years. The ICC was > 0.75. The measurements obtained at T2 were significantly greater than at T1 (p = 0.001). The mean increase in root length was 2.83 mm. There was no significant correlation (p = 0.413; r = 0.261) between root length increase and the time elapsed between T1 and T2. Premolar teeth with incompletely formed roots transplanted to the upper central incisor region showed continued root development during postoperative follow-up.

Aesthetic rehabilitation of a complex crown-root fracture by fragment reattachment with a fiber-reinforced post: A case report

Complex crown-root fractures are characterized by the involvement of both crown and root with pulp exposure. They pose aesthetic, functional, and psychological problems for the patient. Furthermore, they can pose technical difficulties for the practitioner. The purpose of this case report is to describe the management of a complex crown-root fracture of the right upper central incisor with subgingival limit by reattaching the tooth fragment with fiber-reinforced post. We considered a coronal elongation (gingivectomy and osteoplasty) to recreate the biological space and to expose the limit of the fracture line to guarantee the quality of the bond.

Color Ranges and Distribution of Human Teeth: A Prospective Clinical Study.

This study investigated the in vivo color range of human teeth using a research-grade noncontact spectroradiometer, analyzing the effects of gender, age, ethnicity, and lifestyle factors, including diet, smoking, and oral hygiene. A total of 1004 participants were recruited at two research sites and stratified by gender, age, and ethnicity, and data on their dietary and oral habits were collected. Noninvasive color measurements of an upper central incisor were performed using a spectroradiometer and a fiber-coupled Xe-Arc light source. Color differences were computed using the CIELAB and CIEDE2000 color difference formulas, statistically analyzed, and interpreted through comparisons with 50:50% perceptibility (PT) and acceptability (AT) thresholds for dentistry. CIELAB and CIEDE2000 color coordinate values varied significantly. Female teeth appeared lighter and less yellow than men's. Age correlated with darker, more chromatic teeth, stabilizing only after Age 46. Significant ethnic differences were observed, particularly between African-American and Asian participants. Coffee consumption impacted teeth yellowness and chromaticity, while tea had no significant effect. Frequent tooth brushing led to lighter teeth, and tooth whitening considerably influenced color, emphasizing the effect of cosmetic dental treatments. Smoking showed minimal impact, with slight discoloration noted among light smokers compared to nonsmokers. Color coordinate values by gender, age, and ethnicity exhibited statistically significant differences and, in most cases, noticeable color differences. With exceptions, the dietary/oral habits of the patient had a significant impact on the color of human teeth. The findings from this study provide detailed information and understanding of the color range and distribution of human teeth, which can help enhance the esthetic outcome of dental care and, consequently, the patient's satisfaction.

A Case Report of Root Resorption after Tooth Dislocation Replantation

The complete dislocation of the right upper central incisor lasted for more than 2 hours. After 2 weeks of replantation, the ligature was removed. After 1.5 months of reexamination, it was found that the internal and external root absorption of the affected tooth could be slowed down through infection control in the root canal and apical barrier. Reexamination 2.5 months later showed increased bone density around the root of the affected tooth.

Comparative Evaluation of Platelet-rich Fibrin and Treated Dentin Matrix in Regenerative Endodontic Treatment of Nonvital Immature Permanent Teeth: A Randomized Clinical Trial.

Clinical and radiographic evaluation of the efficacy of platelet-rich fibrin (PRF) and treated dentin matrix (TDM) in regenerative endodontic treatment and periapical healing of nonvital immature permanent teeth with chronic apical periodontitis. Twenty-four children aged between 7 and 11 years, each presenting with a nonvital immature permanent upper central incisor, were selected. They were randomly allocated into two groups (n = 12), group I (PRF) and group II (TDM). Baseline clinical findings were recorded, and preoperative cone-beam computed tomography (CBCT) was taken. Follow-up was done clinically for 15 months at 3-month intervals (3, 6, 9, 12, and 15 months), and CBCT was taken at the end of the 15-month follow-up. Root length, apical diameter, radiographic root area (RRA), and size of the periapical lesion were quantitively assessed at the end of follow-up period and compared to the preoperative CBCT. Clinical success was 100% in both groups by the end of the follow-up period. Radiographically, after a 15-month follow-up, there was a significant increase in root length and RRA, and there was also a significant reduction in apical diameter and lesion size within each group (p < 0.05). However, there was no statistically significant difference between both groups regarding the mean percentage of increase in root length and mean percentage of reduction of apical diameter (p > 0.05). On the other hand, PRF showed more increase in RRA and more reduction in lesion size, with a statistically significant difference between both groups (p < 0.05). Both PRF and TDM were clinically successful. Platelet-rich fibrin showed better radiographic outcomes and periapical healing. Platelet-rich fibrin is a viable scaffold to aid further root development and resolution of periapical lesions of nonvital immature permanent teeth. Further studies with different forms of TDM are needed to assess the efficacy of TDM in regenerative endodontic treatment of nonvital immature permanent teeth. How to cite this article: Asal MA, Elkalla IH, Awad SM, et al. Comparative Evaluation of Platelet-rich Fibrin and Treated Dentin Matrix in Regenerative Endodontic Treatment of Nonvital Immature Permanent Teeth: A Randomized Clinical Trial. J Contemp Dent Pract 2024;25(6):563-574.

Accuracy, Time, and Comfort of Different Intraoral Scanners: An In Vivo Comparison Study

Background: The purpose of this study was to compare the accuracy of three different intraoral scanners (IOSs) and to evaluate the patients’ experience. Methods: Thirty subjects were scanned with three different IOSs (TRIOS Color®, iTero Element 5D®, and iTero Lumina®): a sample of 90 maxillary casts was collected. The inclusion criteria were permanent dentition, absence of defects during the dental impression, and complete record of the palatal vault. After the scanning procedure, patients were asked to answer a questionnaire (10 answers, scale from 1 to 10) to compare their experiences with iTero Element and iTero Lumina in the scanning procedure. Results: Differences were recorded in the upper central incisor region (f-ratio of 4.186 for Mesiodistal 1.1 and f-ratio of 4.222 for Mesiodistal 2.1, p &lt; 0.05), while intercanine width Upper 13–23 showed the smallest f-ratio (0.226) when compared to the other results, followed by Mesiodistal 1.4 (0.433). Patients reported more comfort, less pain, decreased duration, and a better technology visualization of the impression with iTero Lumina. No significant differences concerning dryness of the mouth and gag reflex were found. Conclusions: The examined IOSs offer comparable accuracy in capturing dental arch dimensions. The interviewed patients expressed an overall preference for digital impressions performed with iTero Lumina, linked to increased comfort, painless practice, and a better technology visualization of the impression.

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

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. This study aimed to assess the relationship between skin tones and shades of upper anterior teeth among a diverse Nigerian adult population. 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. 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 (β = 0.173, OR =1.19, P < 0.001). The values for canines were more likely to be >2 (β = 0.118, OR =1.12, P = 0.01), but without significant positive relationship to increasingly darker skin tones (β = -0.99, OR =0.91, P = 0.22). 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.

UPPER LIP FRENECTOMY IN A PEDIATRIC DENTAL PATIENT: Clinical case report of a ten-year-old patient from the city of Mato Verde - MG

Lip brakes have the function of limiting the movement of the lips, stabilizing the midline and inhibiting accentuated gingival exposure. The superior labial frenulum is a fold composed of mucous membrane and fibrous tissue. It is attached on one side to the inside of the upper lips and on the other side to the gums in the middle of the jaw. The objective of this study was to report a case of upper lip frenectomy in a pediatric dentistry patient. This is a study with a qualitative approach with a descriptive/observational objective. A survey was carried out in the municipality of Mato Verde-MG at Faculdade Verde Norte (FAVENORTE). A ten-year-old male patient was taken by the guardian to the dental clinic at Faculdade Verde Norte - FAVENORTE, with the following main complaint: “Large space in the front teeth”. After anamnesis, it was found that the patient had no systemic changes. On clinical examination, the presence of diastema between the permanent upper central incisors and a wide and voluminous upper labial frenulum was observed during the upper laboratory treatment. The treatment was surgical removal: Frenectomy using the Modified Archer Technique. In the case reported, it was demonstrated that the surgical technique was performed successfully, where the repositioning of the labial frenulum and new reinsertion were observed, promoting an improvement in the patient's quality of life.

Horizontal Augmentation Using Customized Zirconia Membrane: A Case Report

Background Horizontal bone defects are frequently observed after tooth extraction, primarily resulting from the physiological resorption of the alveolar ridge. Reconstruction of horizontal defects is essential before or during dental implant placement, particularly in the esthetic zone. This case report aims to evaluate the effectiveness of horizontal alveolar ridge augmentation utilizing a customized zirconia membrane. Case Presentation A 20-year-old female patient desired to replace the missing right upper central incisor with a dental implant. The radiographic evaluation showed a concave bone defect, which makes it impossible to place a dental implant. The treatment plan was made for localized ridge augmentation using a customized zirconia membrane (CZM) prior to dental implant placement. Conclusion The customized Zirconia membrane is an effective and very satisfactory treatment option in the management of horizontal defects. Customized zirconia membranes reduce surgical time, facilitate the procedure for the patient and the practitioner, reduce the rate of complications, and achieve good horizontal bone gain.

Periapical surgery and different root obturation protocols for upper central incisor: A finite elements analysis

BackgroundThe aim of this study was to determine the effect of root canal filling using different obturation materials combined with apicoectomy in upper central incisors under loading with 1 N and 100 N. The effect of incomplete root formation was also investigated. MethodsBased on a CBCT-scan, a model of an upper central incisor was created. The model was altered to simulate different clinical situations: root canal treatment, apicoectomy at two different lengths and with different obturation protocols, and immature root formation after trauma. In each model the tooth was loaded with 1 and 100 N, and peak Von Mises stress of bone and tooth, elastic strain of the periodontal ligament, as well as rotation and displacement of the tooth were measured. ResultsPeriapical surgery increases stress in dentin and the surrounding bone. Different obturation materials only produce minor differences in a coronally intact tooth. ConclusionsInterincisal angle or loading direction strongly affects all measured values and needs to be considered when planning periapical surgery or comparing finite element analysis. Immature roots show the highest stress values in this study, reaching half the yield strength of dentine.

Comparison of Upper Central Incisor Torque in the ClinCheck® with and without CBCT Integration: A Cross-Sectional Study.

Controlling root movement is one of the greatest challenges in orthodontic treatment with aligners, like Invisalign® aligners. Cone Beam Computed Tomography (CBCT) integration into ClinCheck®, enabling bone and root visualisation, allows a more accurate follow-up of the teeth position. This study aims to compare torque measurements of the upper central incisors with and without CBCT and relate them to the upper incisor inclination and facial biotype. In a sample of 70 teeth, torque measurements were obtained by importing images into AutoCAD® software (version 2024). The angle between the tooth's long axis with CBCT duplicate and the tooth's long axis without CBCT was obtained to assess the difference. Statistically significant differences between torque measurements with and without CBCT were found, as well as between these measurements and the inclination of the upper incisors. No statistically significant differences were found among the facial biotypes. The average values of 27.8° ± 3.4° and 21.5° ± 3.2° were obtained for the angle between the axes. Torque without CBCT was lower than torque with CBCT, for the same tooth. The angle between the axes had a similar mean for both teeth. CBCT integration into ClinCheck® allows for a more correct torque measurement.

CBCT Evaluation of Alveolar Bone Change and Root Resorption after Orthodontic Treatment: A Retrospective Study.

For years, there has been a long debate about the impact of orthodontic treatment on the periodontium of patients. Therefore, it is important to understand the effects of orthodontic forces on the periodontium. The objective of this study was to evaluate the height of the alveolar bone at the four surfaces of specific teeth and the root length of the central incisors before and after orthodontic treatment. CBCTs from a group of fifty patients were evaluated before (T0) and after orthodontic treatment (T1). Evaluations of the alveolar bone were performed by measuring the distance from the most apical point of the marginal portion to the CEJ at the buccal (B-ABL), lingual (L-ABL), mesial (M-ABL), and distal (D-ABL) surfaces of the central incisor (CI), first premolar (1st PM), and first molar (1st M). Meanwhile, root resorptions were evaluated by measuring the distance from the center of the tooth at the CEJ to the most apical point of the central incisor. The reduction in the alveolar bone level was highest at the buccal segment (75%) and lowest at the distal (42%) segment, although the decrease was not statistically significant. Root resorption, in terms of reduction in the total length, was detected in the upper central incisor. Fixed orthodontic treatment can produce a significant reduction in root length, but not at the level of the alveolar bone.

The Relationship between the Length/Width of the Face and the Length/Width of the Crown of the Permanent Upper Central Incisors.

Background: The face, with its attractiveness, is positively connected with self-esteem and interpersonal relationships, and the maxillary central incisors are the most noticeable teeth and crucial for smile aesthetics. The aim of this study is to examine facial and permanent upper central incisors' clinical crown dimensions and their correlations to establish whether there is a relationship between the length/width of the face and the length/width of the clinical crown of the permanent upper central incisors. Methods: This study included 100 subjects (43 males and 57 females) with a mean age of 17.5 ± 3.4 years before orthodontic treatment. Facial length and width were measured using a cephalometer by the same orthodontist and the upper central incisors' clinical crown lengths and widths were measured using a sliding calliper by the same dental student. Data were analysed using SPSS version 29.0, presenting descriptive statistics for age, facial and upper central incisor crown dimensions, and indices. Pearson's correlation coefficient assessed the relationship between facial features and the upper central incisors' crown. The significance level was p ≤ 0.05. Results: Males exhibit a slightly higher mean value of the face length (11.6 ± 0.8 cm) compared to females' face length (11.2 ± 1.1 cm) and a statistically significant (p < 0.05) higher mean value of the face width (11.7 ± 0.8 cm) compared to females (11.1 ± 0.6 cm). The facial index shows no statistically significant gender difference (males: 99.1 ± 8.4; females: 101.2 ± 11.9, p > 0.05). The upper central incisor crown dimensions are without statistically significant differences between gender and tooth side: males have mean value clinical crown lengths of 10.2 ± 1.1 mm (left) and 10.1 mm ± 1.2 (right) while females have 9.9 ± 1.0 mm (left) and 9.8 ± 0.7 mm (right). Clinical crown widths are also comparable (males: left 9.0 ± 0.7, right 8.9 ± 0.6 and females: left 8.8 ± 0.7, right 8.8 ± 0.7), with no statistically significant differences observed. The tooth index shows no statistically significant difference but there is a statistically significant (p < 0.05) correlation between the facial index and tooth index. Conclusions: Knowledge of the presented data is important for diagnosis and treatment planning and may be useful for restorative dentists, orthodontists, prosthodontists, and maxillofacial surgeons to achieve an aesthetic result. Clinically, our study supports the development of more personalized treatment plans.

Effects of Nail Biting (Onychophagy) on Upper Central Incisors in Children and Young Adolescents

Nail biting (NB) is a repetitive and uncontrolled parafunctional activity that can affect oral health by altering tooth shape and intraoral position. Nowadays, there is not enough scientific evidence about the impact of NB on teeth; therefore, this study aimed to evaluate the effects of NB on the length, width and inclination of upper central incisors. This retrospective study involved 76 patients, 40 males and 36 females, with a mean age of 10.6 ± 0.3 years. Digital scans of the maxillary arch of each patient were recorded. Next, the length, width and inclination of upper central incisors used and not used for NB were measured. Finally, data were analysed with a paired t-test. Statistical analysis showed statistically significant differences in the length and inclination of upper central incisors used for NB compared with those of upper central incisors not used for NB, while the width did not show a significant difference. There were relevant changes in upper central incisors subjected to NB, demonstrating that NB impairs the shape, morphology and inclination of teeth. Therefore, because of the potentially negative consequences of NB, it is recommended that NB not be underestimated.

Contribution of Dental Dimensions in Sex Prediction and Identification

The purpose of this research is to assess the differences of tooth measurements between Bulgarians and Spaniards. The survey included 232 Bulgarians aged 20–40 years. Vestibulo-lingual and mesio-distal dental diameters were obtained by a hand-held laser scanner (FastSCAN Cobra, Polhemus Inc., Colchester VT) and analyzed with SPSS 28.0. We detected significant differences in mesio-distal measurements of upper central incisors, premolars, and molars and mandibular first molars, vestibulo-lingual measurements of upper central incisors, canines and first molars and lower first molars between Bulgarians and Spaniards. Our findings revealed that tooth measurements vary in the populations and thus they can be reliable predictors in forensic identification.