Assessment of the root and canal morphology in the permanent dentition of Saudi Arabian population using cone beam computed and micro-computed tomography - a systematic review.

INTRODUCTION: Root canal treatment procedures require a thorough understanding of root and canal anatomy. The purpose of this systematic review was to examine the morphological differences of teeth root and their canals assessed using cone-beam computed and micro-computed tomography in Saudi Arabian population. METHODOLOGY: An electronic search was conducted in PubMed / Medline, Scopus, Google Scholar, and Web of Science databases until January 2023 to retrieve related studies. "Root canal morphology," "Saudi Arabia," "Micro-CT," and "cone-beam computed tomography" were used as keywords. A modified version of previously published risk of bias assessment tool was used to determine the quality assessment of included studies. RESULTS: The literature search revealed 47 studies that matched the criteria for inclusion, out of which 44 studies used cone beam computed tomography (CBCT) and three were micro-computed tomography (micro-CT) studies. According to the modified version of risk of bias assessment tool, the studies were categorized as low, moderate, and high risk of bias. A total of 47,612 samples were included which comprised of either maxillary teeth (5,412), or mandibular teeth (20,572), and mixed teeth (21,327). 265 samples were used in micro-CT studies while 47,347 teeth samples were used in CBCT studies. Among the CBCT studies, except for three, all the studies were retrospective studies. Frequently used imaging machine and software were 3D Accuitomo 170 and Morita's i-Dixel 3D imaging software respectively. Minimum and maximum voxel sizes were 75 and 300 µm, Vertucci's classification was mostly used to classify the root canal morphology of the teeth. The included micro-CT studies were in-vitro studies where SkyScan 1172 X-ray scanner was the imaging machine with pixel size ranging between 13.4 and 27.4 µm. Vertucci, Ahmed et al. and Pomeranz et al. classifications were applied to classify the root canal morphology. CONCLUSION: This systematic review revealed wide variations in root and canal morphology of Saudi population using high resolution imaging techniques. Clinicians should be aware of the common and unusual root and canal anatomy before commencing root canal treatment. Future micro-CT studies are needed to provide additional qualitative and quantitative data presentations.

Exploring age and gender variations in root canal morphology of maxillary premolars in Saudi sub population: a cross-sectional CBCT study.

BACKGROUND: In complex teeth like maxillary premolars, endodontic treatment success depends on a complete comprehension of root canal anatomy. The research on mandibular premolars' root canal anatomy has been extensive and well-documented in existing literature. However, there appears to be a notable gap in available data concerning the root canal anatomy of maxillary premolars. This study aimed to explore the root canal morphology of maxillary premolars using cone-beam computed tomography (CBCT) imaging, considering age and gender variations. METHODS: From 500 patient CBCT scans, 787 maxillary premolar teeth were evaluated. The sample was divided by gender and age (10-20, 21-30, 31-40, 41-50, 51-60, and 61 years and older). Ahmed et al. classification system was used to record root canal morphology. RESULTS: The most frequent classifications for right maxillary 1st premolars were 2MPM1 B1 L1 (39.03%) and 1MPM1 (2.81%), while the most frequent classifications for right maxillary 2nd premolars were 2MPM1 B1 L1 (39.08%) and 1MPM1 (17.85%). Most of the premolars typically had two roots (left maxillary first premolars: 81.5%, left maxillary second premolars: 82.7%, right maxillary first premolars: 74.4%, right maxillary second premolars: 75.7%). Left and right maxillary 1st premolars for classes 1MPM1 and 1MPM1-2-1 showed significant gender differences. For classifications 1MPM1 and 1MPM1-2-1, age-related changes were seen in the left and right maxillary first premolars. CONCLUSION: This study provides novel insights into the root canal anatomy of maxillary premolars within the Saudi population, addressing a notable gap in the literature specific to this demographic. Through CBCT imaging and analysis of large sample sizes, the complex and diverse nature of root canal morphology in these teeth among Saudi individuals is elucidated. The findings underscore the importance of CBCT imaging in precise treatment planning and decision-making tailored to the Saudi population. Consideration of age and gender-related variations further enhances understanding and aids in personalized endodontic interventions within this demographic.

Micro computed tomography (Micro-CT) characterization of root and root canal morphology of mandibular first premolars: a systematic review and meta-analysis.

INTRODUCTION: Mandibular first premolars are familiar with their varied root canal morphology, causing difficulties and challenges for successful endodontic procedures. This systematic review and meta-analysis aim to study the characterization of root and canal morphology of the first mandibular premolar using micro-computed tomography. METHODOLOGY: The literature search was conducted using electronic web databases like PubMed, Scopus, ScienceDirect and Cochrane with the chosen MeSH key words and data was retrieved until May 2023. Further to perform the statistical analysis, R v 4.3.1 software with "meta", 'metafor" "metaviz" " ggplot2" package was used, and results were represented by odds ratios (OR) and the percentage of forest plots along a 95 per cent confidence interval (CI). RESULTS: The total number of studies meeting the inclusion criteria was 13; these studies were conducted on mandibular first premolar using Micro-CT; the total sample size was 1817. To scan the sample, an X-ray micro-focus CT system (Siemens Inveon CT, Erlangen, Germany) was used in four studies and seven different machines were used in the respective studies. Mimics 10.01 software (Materialize, Leuven, Belgium) and NRecon v.1.6.9 software (Bruker, Kontich, Belgium) were commonly operated. The minimum and maximum voxel size ranges between 11.94 and 50 µm. Vertucci's classification was frequently used (9), while one study applied Ahmed et al. and Vertucci's classification. CONCLUSION: This systematic review provides essential information about the root and canal configurations, radicular grooves, accessory canals, and apical foramina through Micro-CT, aiming to improve the accuracy of endodontic treatment and help practitioners.

Morphometric variations and nonmetric anatomical traits or anomalies of the primary molar teeth, plus the molars' size thresholds for sex identification.

INTRODUCTION: Morphological and morphometric features of the teeth are of interest to various clinical and academic dental and medical fields including prosthodontics, orthodontics, anatomy and anthropology, pathology, archeology, and forensic dentistry. These have been more or less researched in the case of the permanent dentition. However when it comes to the primary dentition, the literature is scarce and controversial. No study worldwide exists on the cutoff points (thresholds) for sex identification; no study exists on metric or nonmetric traits of deciduous teeth in Iranians. Hence, the aim of the study was to assess both the metric and nonmetric traits of primary molars, as well as their cut-off points for sex identification. METHODS: In this epidemiological cross-sectional study, pretreatment casts of 110 children (51 boys and 59 girls) aged 6 to 12 years were collected. Maxillary and mandibular first and second primary molars were evaluated regarding their metric traits (mesiodistal and buccolingual widths) and 9 nonmetric traits (Accessory cusp on the upper D, Accessory cusp on the lower D, Fifth cusp on the upper E, Carabelli's cusp on the upper E, Protostylid on the lower E, Fifth cusp on the lower E, Sixth cusp on the lower E, Tuberculum intermedium [metaconulid] on the lower E, and Deflecting wrinkle on the lower E). ROC curves were used to identify cut-off points for sex determination as well as the usefulness of metric measurements for this purpose. Data were analyzed using independent-samples and paired-samples t-tests, McNemar, Fisher, and chi-square tests, plus Pearson and Spearman correlation coefficients (α = 0.05). RESULTS: All the primary molars' coronal dimensions (both mesiodistal and buccolingual) were extremely useful for sex identification (ROC curves, all P values ≤ 0.0000099). Especially, the mandibular primary molars (areas under ROC curves [AUCs] between 85.6 and 90.4%, P values ≤ 0.0000006) were more useful than the maxillary ones (AUCs between 80.4 and 83.1%, P values ≤ 0. 0000099). In the mandible, the first primary molar (maximum AUC = 90.4%) was better than the second molar (maximum AUC = 86.0%). The optimum thresholds for sex determination were reported. Sex dimorphism was significant in buccolingual and mesiodistal crown widths of all the primary molars (all P values ≤ 0.000132), but it was seen only in the case of 2 nonmetric traits: Deflecting wrinkle (P = 0.001) and Tuberculum intermedium (metaconulid, P = 0.029) on the lower Es, taking into account the unilateral and bilateral cases. The occurrence of nonmetric traits was symmetrical between the right and left sides (all P values ≥ 0.250). All mesiodistal and two buccolingual molar measurements were as well symmetrical (P > 0.1); however, two buccolingual measurements were asymmetrical: in the case of the maxillary E (P = 0.0002) and mandibular D (P = 0.019). There were three weak-to-moderate correlations between the nonmetric traits of the mandibular second molars (Spearman correlations between 22.7 and 37.5%, P values ≤ 0.045). Up to 6 concurrent nonmetric traits were observed in the sample, with 53.6% of the sample showing at least 2 concurrent nonmetric traits at the same time, without any sex dimorphism (P = 0.658). CONCLUSION: Sex dimorphism exists considerably in primary molars' sizes, but it is not as prevalent in their nonmetric traits or abnormalities. Primary molars' crown sizes are useful for sex identification; we calculated optimum cut-off points for this purpose, for the first time.

Can self-assessment ability predict student performance in a dental anatomy course?

INTRODUCTION: The development of early self-assessment skills and determining its correlation with academic performance could provide evidence to alter dental curricula. The aim of this retrospective study was to examine the relationships between students' early self-assessment ability in waxing and three different evaluation methods (waxing assessment, written examinations, and tooth identification examination) in a dental anatomy course. MATERIALS AND METHODS: The dental anatomy scores during the academic years of 2018-2019 and 2019-2020 from two cohorts of second-year pre-doctoral dental students at the Harvard School of Dental Medicine were analyzed. Regression analyses were completed to assess the relationship between all evaluation methods. RESULTS: There was a statistically significant correlation between self-assessment ability and the waxing assessment but no significant correlation between self-assessment ability and the other evaluation methods. CONCLUSION: Our results showed that the introduction of self-assessments in dental anatomy waxing was correlated with successful waxing skills. Furthermore, a relevant finding is that students who received higher classifications were also capable of doing better self-assessments. These findings provide evidence that impacts dental curricula.

Identifying teeth and tooth fragments from digital 3D models.

Dental anatomy is an essential skill for human identification in forensic odontology. With the advent of technology enabling virtual autopsies, there is scope for virtual consultation by forensic odontologists especially when the expertise is unavailable but needed in zones of conflict or disasters. This study aimed to investigate potential benefits and challenges of identifying intact and damaged teeth from 3D scanned digital models. Ten 3D tooth models - nine permanent and deciduous human teeth and one animal tooth were uploaded on a hosting platform. A 3-part survey was circulated among 60 forensic odontologists with questions about demography (P1), tooth identification of the scanned 3D models (P2) and the perceived usefulness of 3D models for tooth identification (P3). This was the first time that a survey required the identification of individual human teeth (intact or not) and animal tooth combined. The response rate for study participation was 58%. Substantial agreement among participants was seen in the determination of tooth classification (i.e., molars, premolars) or non-human and tooth within the same tooth class (i.e., lateral incisors, second molar) (both k=0.61). The least agreement (k=0.21) was seen in identification of tooth according to the FDI notation with a mean accuracy of 0.34. While most responders correctly identified the animal tooth, most incorrect responses were seen in the identification of the intact third molar. While 3D-scanned teeth have the potential to be identified virtually, forensic odontologists should continuously test their skills in tooth morphology and dental anatomy of humans (damaged or not) and animals.

Visualizing Anatomy in Dental Morphology Education.

Tooth morphology is a foundation course for all dental healthcare students including dentists, dental hygiene, dental therapy, and dental nursing students. This chapter explores the conventional and innovative teaching methods to deliver tooth morphology educational modules. The teaching tools are explored with a 2D and 3D lens, with a particular focus on visualization, student understanding, and engagement. Traditional methods of teaching tooth morphology must be complemented with innovative pedagogical approaches in order to maintain student's attention and accommodate their diverse learning methods. Teaching 3D anatomy enables students to visualize and spatially comprehend the link between various anatomical components. Online tests and quizzes motivate students and are also beneficial in preparing students for exams. Online self-examinations offering visualization with 3D teeth enable students to evaluate their knowledge and offers immediate feedback, which aids in the long-term retention of information. These tools can be as efficient as other teaching methods, allowing the students to study at their own pace and with repetition. The authors conclude that blended and innovative teaching methods should supplement student learning and not replace, traditional face-to-face educational methods.

Evaluation of root and canal morphology of mandibular premolar amongst Saudi subpopulation using the new system of classification: a CBCT study.

BACKGROUND: The clinician should have complete knowledge of the normal anatomy of the root as well as complexities in the root canal configuration for a better outcome, as missed or improper handling of the canal system can lead to the failure of an entire endodontic procedure. The present study aims to assess the morphology of roots and canals in permanent mandibular premolars in the Saudi subpopulation with a new classification system. METHODS: The present study includes 1230 mandibular premolars (645 first premolars and 585-second premolars) from 500 CBCT images of the patients, including retrospective data. iCAT scanner system (Imaging Sciences International, Hatfield, PA, USA) was used to obtain the images; scanning of 8 × 8 cm images was performed at 120 KVp and 5-7 mA with a voxel size of 0.2 mm. The new method of classification presented by Ahmed et al. 2017 was used to record and classify the root canal morphology, followed by recording the differences regarding the age and gender of the patients. Comparison of canal morphology in lower permanent premolars and its association with gender and age of the patients was done by Chi-square test/ Fisher exact test; the significance level was set at 5% (p ≤ 0.05). RESULTS: The left mandibular 1st and 2nd premolars with one root were 47.31%, with two roots were 2.19%. However, three roots (0.24%) and C-shaped canals (0.24%) were reported only in the left mandibular 2nd premolar. The right mandibular 1st and 2nd premolars with one root were 47.56%, with two roots were 2.03%. The overall percentage of the number of roots and canals in the first and second premolars 1 PM 1 (88.38%), 2 PM 1 B 1 L 1 (3.5%), 2 PM B 1 L 1 (0.65%), 1 PM 1-2-1 (3.08%), 1 PM 1-2 (3.17%), 1 PM 1-2-1-2 (0.24%), 3 PMMB 1 DB 1 L1 (0.48%). However, the C-shaped canals (0.40%) were reported in right and left mandibular second premolars. No statistically significant difference was reported between mandibular premolars and gender. A statistically significant difference was reported between mandibular premolars and the age of the study subjects. CONCLUSION: Type I (1 TN 1) was the major root canal configuration in permanent mandibular premolars, which was higher among males. The CBCT imaging provides thorough details about the root canal morphology of lower premolars. These findings could support diagnosis, decision-making, and root canal treatment, for dental professionals.

Emil Zuckerkandl and his Dental Tubercle (Historical Note).

One of the eponyms most frequently cited in dental morphology texts, together with the Carabelli tubercle of the first permanent maxillary molars, is the Zuckerkandl tubercle of deciduous molars. However, references about Emil Zuckerkandl in the field of dental history and this particular entity are scarce. The reason this dental eponym was pushed "into the shadows" probably lies in the many other anatomical parts (including another tubercle, the pyramidal one of the thyroids), which took their names from this great anatomist.

Leonardo da Vinci and dental anatomy.

Leonardo da Vinci, the Renaissance polymath, is still recognized today-above all for his oil paintings and mechanical inventions. His anatomical studies have attracted less attention, even though he devoted over 30 years of his life to them. This paper outlines Leonardo's career and research methods and focuses on the importance of his medical images for anatomical research and teaching. Following a short presentation of the state of (dental) medicine in the early Renaissance period, it offers a description of five of his cranial drawings that show the anatomy of the teeth, the nervous and vascular system on inner and outer tables of the skull and the paranasal sinuses in great detail. Leonardo da Vinci had obviously discovered and depicted the maxillary sinus 150 years before the anatomist Nathaniel Highmore, who is usually credited with this discovery. Other anatomical drawings by Leonardo address the correct human dental formula and describe the morphology of the four types of teeth. His handwritten notes show that he recognized the connection between tooth form and function. Finally, this paper evaluates the influence of these discoveries and innovations on the development of dentistry and its establishment as a scientific discipline. There is no doubt that Leonardo da Vinci's preoccupation with the anatomy of the maxillofacial region influenced the development of anatomy and dentistry, even though he never published his anatomical research.

Clinical insights into the three-dimensional anatomy of cheek teeth in alpacas based on micro-computed tomography - Part 2: Maxillary cheek teeth.

BACKGROUND: Scientific knowledge regarding alpaca dentistry is relatively limited despite its clinical implications. The present gap in available supportive data leads to limited treatment options for dental pathology in alpacas in comparison to other species. The main goal of this study was to gain novel insights into the general and pulp morphology of maxillary cheek teeth to allow development of more advanced treatment strategies in the future. Also, the risk of causing pulp exposure when floating maxillary cheek teeth was of particular interest. Concurent research focusing on the anatomy of mandibular cheek teeth has been performed accordingly. The results obtained in mandibular teeth are expected to be non-extrapolatable because of the structural differences between mandibular and maxillary teeth. RESULTS: Pulp morphology of maxillary cheek teeth showed great variation. A common pulp chamber was identified in 46/83 (55.4%) teeth with a mean dental age of 2 years and 7 months (± 2 years and 5 months). Pulpal segmentation was more commonly observed in teeth of increasing age. Full columnar segmentation was seen in 33/69 teeth (47.8%), whereas within-column segmentation was observed in 36/83 teeth (43.4%). Age and degree of segmentation of the pulpal tissue varied greatly according to Triadan position. Physical contact between roots of adjacent teeth was found in the majority of examined molars (range 82-94%) which resulted in morphological adaptations at the level of the root tips. The measured sub-occlusal dentinal thickness was as low as 0.46 mm above pulp horn 2 in a 14 years and 11 months old Triadan 09, emphasizing the risk of pulp exposure attributed to dental floating. CONCLUSION: This study offers an objective description of age-dependent maxillary cheek teeth pulp morphology in alpacas. Current findings are of great value to provide a basis for the development of tooth-saving techniques as a treatment for dental disease in this species. Observed physical contact between the roots of different examined molars may be a facilitating factor in the spread of apical infection in chronically diseased cases. Finally, a conservative approach regarding dental floating is recommended in order to avoid iatrogenic damage to pulp tissue.

Evaluation of root canal morphology in permanent maxillary and mandibular anterior teeth in Saudi subpopulation using two classification systems: a CBCT study.

BACKGROUND: Adequate knowledge of root canal morphology and possible variations is essential to achieve perfect root canal treatment and overcome treatment failure. Appropriate knowledge on root and canal morphology, communication, and documentation amongst dentists will be challenging from a diagnostic and successful treatment point of view. METHODS: A total of 3420 samples were included in this study from 285 cone-beam computed tomography images of the Saudi residents, including 171 males and 114 females aged 15 to 68 years from retrospective data dated from January 2018 to April 2021. The images were examined in sagittal, axial and coronal views using a 3D version software 1.0.10.6388. The number of canal and canal morphology was recorded using Vertucci and the new classification system. The SPSS 26 was used to conduct the statistical analysis as descriptive statistics such as mean; standard deviation and frequency were calculated. The Chi-square test analysed the data with the significance level set at 0.05. RESULTS: A total of 285 subjects participated in the study. Majority of the participants were Saudi nationals (80.7%), followed by Indian (7.4%), Pakistani (4.2%) and other nationalities. According to Vertucci and the new classification system, Type I and 1TN1 were the most common types, followed by Type III and Type IV, and then 1TN1-2-1 and 1TN1-2 in mandibular anteriors. The prevalence of canal variations in mandibular canine was higher in females than in males (P = 0.002). Maxillary laterals and mandibular anteriors showed the significant difference in the prevalence of root canal variation in relation to the ethnicity (P = 0.001) and age of the patients. Younger patients showed more variations than the older patients (P = 0.012, P = 0.023, P = 0.001, P = 0.001) in terms of maxillary laterals, mandibular central, laterals and canines, respectively. CONCLUSION: Mandibular permanent anteriors showed a wide range of canal variations and canal complexity. Males and females did not demonstrate a wide range of variation in the root canal morphology except for the canines in relation to the gender of the patients.

Associations between 44 nonmetric permanent dental traits or anomalies with skeletal sagittal malocclusions and sex, besides correlations across the variations or abnormalities.

INTRODUCTION: Nonmetric dental traits and the shape, size, or number of dental anomalies are essential to various dental fields such as orthodontics, dental anatomy, anthropology, pathology, and forensic dentistry. Nonetheless, many are not well assessed worldwide. Moreover, most studies are limited to a few nonmetric traits. Therefore, we aimed to examine several nonmetric dental traits/anomalies. METHODS: In this cross-sectional epidemiological study, ~ 9000 permanent teeth of 331 non-syndromic orthodontic patients (radiographs and dental casts) with fully erupted permanent dentitions (except the third molars and some cases of a few teeth missing or excluded) were evaluated by two observers, each twice, in search for 62 nonmetric traits/shape-number-size anomalies. The traits/anomalies of interest were supernumerary, microdontia, peg-shaped lateral, shovelings, talon cusps, Carabelli cusps, fifth/sixth/seventh cusps on the molars, hypocone/hypoconulid absence, protostylid, deflecting wrinkle s, canine mesial ridge, distal trigonid crest, canine distal accessory ridge, accessory cusps in the mesial/distal marginal ridges, mesial/distal accessory ridges, and accessory cusps in the lingual of the mandibular premolars and second molars). Data, at both patient/quarter levels, were analyzed regarding the associated factors (skeletal Angle classes, crowding, sex, and sides) as well as the correlations among traits, using the chi-square test and Spearman correlation coefficient (α = 0.05). RESULTS: Prevalence rates of 44 traits/anomalies were reported (18 out of the 62 searched traits/anomalies were not found [prevalence = 0%]). Microdontia and accessory cusps on the marginal ridge of the second mandibular molars were significantly more common in women (P < 0.05). Canine talon cusp and distal trigonid crest of the second mandibular molars were more prevalent in men (P < 0.05). Shoveling, canine talon cusp, canine distal accessory ridge, and accessory cusp in the first premolar might be more prevalent in skeletal Angle class II; whereas, accessory cusp in the mesial marginal ridge of the second premolar might be rather more prevalent in skeletal Angle class I (P < 0.05). Few dental traits were positively and moderately or strongly correlated with each other (Spearman Rho ≥ 0.4, P < 0.0005). CONCLUSIONS: Sex dimorphism was uncommon in nonmetric dental traits/anomalies. Skeletal malocclusions may be associated with a few dental abnormalities or variations.

The effectiveness of a 3D virtual tooth identification test as an assessment tool for a dental anatomy course.

INTRODUCTION: There has been a recent demand in dental education for distance learning and the use of virtual assessment tools that can leverage technology to potentially replace physical testing facilities. However, virtual tools that evaluate student learning should be validated prior to adoption. The aim of this study was to investigate the effectiveness, efficiency and user satisfaction of a 3D tooth identification test for a dental anatomy course that can be given remotely. MATERIALS AND METHODS: First-year dental students (n = 41) enrolled in a dental anatomy course took both traditional in-person practical and virtual 3D tooth identification tests consisting of 25 test items. The test scores, average test durations, faculty time commitment and user perception were collected and analysed. Pearson product-moment correlation coefficients (p < .05) were determined for the criterion measures including real tooth identification test scores, comprehensive written examination and overall grade for the course. RESULTS: The average number of correct answers for the real and 3D virtual tooth identification examination was 21.3 ± 2.65 and 20.7 ± 2.56, respectively. The average test duration for the real and 3D virtual tooth identification test was 25:00 and 21:16 min, respectively. There was a positive correlation (p < .05) of the 3D virtual tooth identification test with the real tooth identification test (0.368), comprehensive written examination (0.334) and the overall course grade (0.646). The total faculty time commitment for the real and 3D virtual tooth identification test was 96 and 65 min, respectively. The students cited difficulty in manipulating the 3D models. CONCLUSION: This study presents evidence that the 3D virtual tooth identification test can be used to assess dental students' understanding of dental anatomy effectively and efficiently.

The soap carving versus the digital sculpting: Evaluation of students' preferences and performance in dental anatomy course: Pilot study.

PURPOSE/OBJECTIVES: The aim of this study was to evaluate the change in students' preferences between soap carving (SC) and digital sculpting (DS) methods after obtaining tooth with both methods, their opinions about the methods and their performance in the dental anatomy course. MATERIALS AND METHODS: The SC and DS methods were demonstrated. Students were asked to obtain a maxillary central incisor by both methods and to record time. Students' preferences were asked both before and after applying both methods. The level of significance for statistical analysis was set at p ≤ .05. RESULTS: Forty first year preclinical students (24 female, 16 male) participated in this study. Their mean age was 19.38 years ±1.00 year. There was a statistically significant difference between the mean time of the DS method according to gender (p = .004) and the mean time of DS and SC methods for females (p = .015). There was also a statistically significant difference between preferences of students for "In the future while treating the patient in the clinic, I learned with ………… method in the preclinic will be more useful for me." statement, before and after applying both methods (p = .034). CONCLUSIONS: The obtaining the tooth of the students with DS method were longer than with SC method (especially in the females). After applying both methods, the students changed their minds that learning the information about the SC and DS methods would have a similar effect when treating patients in the clinic.

Variation of Permanent Teeth Crowns in Three Nigerian Ethnic Populations.

BACKGROUND: Tooth variation within populations is important for anthropologists and dentists. The objective was to compare crown dimensions among three Nigerian ethnic populations. MATERIALS AND METHODS: An electronic caliper was used to measure mesiodistal and buccolingual tooth width of maxillary and mandibular permanent teeth except third molars from study casts of 132 Nigerian subjects with a mean age of 19.03 ± 4.27 years. The Hausa sample was 50 (37.9%) subjects (25 males and 25 females); the Yoruba population was 50 (37.9%) subjects (15 males and 35 females) and the Igbo sample was 32 (24.2%) subjects (16 males and 16 females). Single teeth and sums of groups of teeth were compared between males and females within and among the three populations using analysis of variance. RESULTS: The findings indicated that (1) differences between antimeres are of small magnitude and of no statistical significance; (2) Significant gender differences in tooth dimension was observed with Yoruba and Hausa males having significantly larger teeth but a significant gender difference was only observed for mesiodistal width of the maxillary second molars in the Igbo population; (3) there is a greater similarity among Yoruba and Igbo subjects with differences from their Hausa counterparts with a magnitude considered statistically and clinically significant. CONCLUSION: The crown dimensions of Hausa males and females were significantly smaller than their Yoruba and Igbo counterparts. There were similarities in crown dimensions between Yoruba males and females and their Igbo counterparts. Sexual dimorphism of crown size was observed in the three ethnic groups.

CONTEXTE: La variation incisive dans une population est tres important chez les anthropologues et les dentiste. L'objective de cet oeuvre c'est de comparer les dimensions des couronnes parmi les trios populations ethniques du Nigeria. MATERIEL ET METHODES: Une coulisse electronique a ete utilise pour measure la mesiodistale et le largeur des dents buccolingue de maxilaire et mandibulaire des dents permanent excepte le 3eme molaire, d'apres l'etude sur 132 Nigerians avec un age moyen de 19.03 ± 4.27 ans.L'echantillon des Haoussas etaient 50 (37.9%) sujets (25 males et 25 femelles); la population des Yoruobas etaient 50 (37.9%) sujets (15 males et 5 femmes) et l'echantillon des Igbos etaient 32 (24.2%) sujets (16 males et 16 femmes) des dents individuels et le total de groupe de dents a ete compare entre les hommes et les femmes des trois populations utilisant l' analyse de variance. RESULTATS: Le resultat a indique que (1) les differences entre les antimeres sont de peu magnitude et n'ont pas de signification statistique; (2) La signification de difference de gendre dans la dimension de dent a ete observe chez les males Yoruoba et les males Hauossa qui ont des dents plus large mais une difference de gendre significative a ete observe seulment pour le largeur mesiodistal du second molaire maxillaire dans la population des Igbos ; (3) il y a une grand similarite entre les sujets Yoruobas et Igbos en comparaison a leurs voisin Haoussa avec une magnitude considere statistiquement et cliniquement significative. CONCLUSION: Les dimensions des couronnes des dents de males et femmes Hauossa etaient plus petit en comparaison aux Yoruoba et Igbo . Il y avaient des similarities dans la dimension de couronne des males et femmes Yoruoba et les Igbo . Le dimorphisme sexual de la taille de couronne a ete observe dans les trios groupes ethniques. Most cle: La difference de gendre; l'Anatomie dentaire; Le Nigeria; La population genetique.

Clinical insights into the three-dimensional anatomy of cheek teeth in alpacas based on micro-computed tomography. Part 1: mandibular cheek teeth.

BACKGROUND: Despite dental disease being a common health concern in alpacas, important dental pathology including apical infection, remains poorly understood. Treatment options are limited compared to veterinary dentistry techniques in other species. The primary goal of this study was to increase understanding of the external and internal anatomy of mandibular cheek teeth to enable the development of tooth sparing techniques in this species. Also, an objective evaluation of the sub-occlusal dentinal thickness in normal mandibular cheek teeth is warranted to understand the risks associated with reduction of overgrown teeth. RESULTS: Overall pulp anatomy was variably characterized by the presence of a common pulp chamber in younger teeth, and segmentation of pulp cavities into multiple separate pulp entities within the same tooth with increasing age. A common pulp chamber was identified in 55.3% (26/47) of teeth with a mean dental age of 1 year and 11 months (± 1 year and 8 months). Columnar segmentation was recorded in the remaining teeth with a mean dental age of 6 years and 5 months (± 3 years and 11 months). Age of segmentation of the common pulp chamber into multiple separate pulp entities shows wide variation and is dependent of the specific Triadan position. The present study illustrates the presence of disto-mesial root contacts between adjacent tooth roots, often leading to morphological adaptations, most frequently observed between Triadan 09-10s (80%) and 10-11s (67%). The measured sub-occlusal dentinal thickness was as low as 1.11 mm over some pulp horns. The sub-occlusal dentinal thickness was lower than 2, 3, and 4 mm in 13.1, 38.1 and 61.4% of performed measurements, respectively. CONCLUSION: This study provides detailed information on age-dependent mandibular cheek teeth anatomy in alpacas, which may support the use and development of advanced dental treatments in this species such as endodontics and tooth sectioning techniques. Apical morphological adaptations caused by disto-mesial root contact between adjacent mandibular cheek teeth are clearly illustrated. The limited amount of sub-occlusal secondary dentin warrants a cautious approach with regards to dental floating in alpacas.

A systematic approach to contouring and polishing anterior resin composite restorations: A checklist manifesto.

PURPOSE: This article presents a systematic, step-by-step checklist approach to be used for contouring and polishing anterior resin composite restorations to achieve maximum esthetics efficiently. CLINICAL CONSIDERATIONS: This checklist is intended to be used to take the guesswork out and streamline the process to predictably, practically, and repeatedly contour and polish anterior resin composite restorations. The practitioner's knowledge of basic dental anatomy combined with this step-by-step checklist facilitates identifying and modifying the final restoration to an anatomically correct form, thus satisfying the most esthetically demanding patients. This approach is demonstrated with case presentation of direct resin veneers in a young female, which resulted in an improved smile that satisfied her esthetic desires. CONCLUSIONS: The use of standardized protocols facilitates and expedites daily procedures in dentistry. Specifically, this checklist protocol, which is geared towards contouring and polishing anterior direct resin composite restorations. CLINICAL SIGNIFICANCE: The clinical technique presented in this article shows the advantages of using a step-by-step checklist approach to predictably and efficiently obtain ideal esthetics when performing anterior resin composite restorations.

Automated cephalometric landmark detection with confidence regions using Bayesian convolutional neural networks.

BACKGROUND: Despite the integral role of cephalometric analysis in orthodontics, there have been limitations regarding the reliability, accuracy, etc. of cephalometric landmarks tracing. Attempts on developing automatic plotting systems have continuously been made but they are insufficient for clinical applications due to low reliability of specific landmarks. In this study, we aimed to develop a novel framework for locating cephalometric landmarks with confidence regions using Bayesian Convolutional Neural Networks (BCNN). METHODS: We have trained our model with the dataset from the ISBI 2015 grand challenge in dental X-ray image analysis. The overall algorithm consisted of a region of interest (ROI) extraction of landmarks and landmarks estimation considering uncertainty. Prediction data produced from the Bayesian model has been dealt with post-processing methods with respect to pixel probabilities and uncertainties. RESULTS: Our framework showed a mean landmark error (LE) of 1.53 ± 1.74 mm and achieved a successful detection rate (SDR) of 82.11, 92.28 and 95.95%, respectively, in the 2, 3, and 4 mm range. Especially, the most erroneous point in preceding studies, Gonion, reduced nearly halves of its error compared to the others. Additionally, our results demonstrated significantly higher performance in identifying anatomical abnormalities. By providing confidence regions (95%) that consider uncertainty, our framework can provide clinical convenience and contribute to making better decisions. CONCLUSION: Our framework provides cephalometric landmarks and their confidence regions, which could be used as a computer-aided diagnosis tool and education.

Teaching dental anatomy & morphology: An updated clinical- & digital-based learning module.

INTRODUCTION: Dental Anatomy and morphology learning is an essential component of the dental curriculum; students introduced to dental morphology in a detailed textbook style lecture format often have difficulty transferring that knowledge to the associated clinically related activities. The purpose of this article is to describe the rationale, components and advantages of an updated dental anatomy module and present a comparison of student course evaluations for those who received the updated module (CDM) versus those who received the traditional module (TM). METHOD: An updated module was implemented at the University of Kentucky College of Dentistry (UKCD). The updated module consisted of clinically based lectures and incorporated digital technologies in both lecture and laboratory portions of the course as well as a patient-based aesthetic wax-up exercise. The goal of the updated module is to shift emphasis away from decontextualised technical learning towards more active and clinically applicable learning that improves classroom interaction and takes advantage of the current technologies available. RESULTS: The results were statistically analysed using a two-sample t test. The updated module was statistically significantly highly rated by students. CONCLUSION: The updated module was highly appreciated and rated by students. An update to the educational method of teaching dental anatomy and morphology is proposed, clinical dental anatomy teaching results in enhanced students' engagement and assessment. More research and proper strategic planning for implementation of digital technology into the dental anatomy curriculum are needed to adequately utilise these resources.