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Placodonts were durophagous reptiles of the Triassic seas with robust skulls, jaws, and enlarged, flat, pebble-like teeth. During their evolution, they underwent gradual craniodental changes from the Early Anisian to the Rhaetian, such as a reduction in the number of teeth, an increase in the size of the posterior palatal teeth, an elongation of the premaxilla/rostrum, and a widening of the temporal region. These changes are presumably related to changes in dietary habits, which, we hypothesise, are due to changes in the type and quality of food they consumed. In the present study, the dental wear pattern of a total of nine European Middle to Late Triassic placodont species were investigated using 2D and 3D microwear analyses to demonstrate whether there could have been a dietary shift or grouping among the different species and, whether the possible changes could be correlated with environmental changes affecting their habitats. The 3D analysis shows overlap between species with high variance between values and there is no distinct separation. The 2D analysis has distinguished two main groups. The first is characterised by low number of wear features and high percentage of large pits. The other group have a high feature number, but low percentage of small pits. The 2D analysis showed a correlation between the wear data and the size of the enlarged posterior crushing teeth. Teeth with larger sizes showed less wear feature (with higher pit ratio) but larger individual features. In contrast, the dental wear facet of smaller crushing teeth shows more but smaller wear features (with higher scratch number). This observation may be related to the size of the food consumed, i.e., the wider the crown, the larger food it could crush, producing larger features. Comparison with marine mammals suggests that the dietary preference of Placochelys, Psephoderma and Paraplacodus was not exclusively hard, thick-shelled food. They may have had a more mixed diet, similar to that of modern sea otters. The diet of Henodus may have included plant food, similar to the modern herbivore marine mammals and lizards. [ABSTRACT FROM AUTHOR]

The article focuses on novel concepts for dental treatment planning such as RAW, digital Skyn workflow that aims to copy intact teeth and transfer information to dental restorations by using digital technology. It mentions dental morphology and tooth shape seen by dentist and technician are interpreted by the computer as a three-dimensional geometric mathematical model. It also mentions Polymethyl methacrylate (PMMA) milled restorations are a perfect alternative to bis-acryl provisionals.

Background: Tooth size discrepancy is defined as an imbalance in size between each tooth. To obtain good occlusion with overbite and overjet, the maxillary and mandibular teeth must be of the appropriate size. One of the causes of malocclusion is the mismatch of the mesiodistal size of the teeth to the arch of the jaw. The relation of teeth with a large maxillary mesiodistal size while the mandibular mesiodistal size is small, it is impossible to get an ideal occlusion. This condition is known as tooth size discrepancy and can be a problem when determining the orthodontic treatment plan and when achieving the final orthodontic treatment outcome. Purpose: this study aimed to describe Bolton's analysis in cases of Class I, II, and III malocclusions. Review(s): The literature sources used in preparing the review were through databases PubMed and Google Scholar with the keywords tooth size discrepancy, Bolton analysis, and Class I, II, and III malocclusions. From the results of the researchers' measurements on malocclusions in the Angle Classification Class I and II, The anterior ratio was different in several cases, while in Class III the results were greater than the Bolton ratio, where the size of the lower jaw teeth was larger than the maxillary teeth, especially in the anterior ratio. Conclusion: Bolton's analysis can be applied to all cases regardless of the type of malocclusion, gender, or race, and remains an important investigation before starting treatment for post-treatment arch stability. [ABSTRACT FROM AUTHOR]

Copyright of Kieferorthopädie: die Zeitschrift für die Praxis is the property of Quintessenz Verlags GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Having a thorough understanding of classical esthetic principles, including basic tooth shape and form rules, is crucial for clinicians to achieve successful esthetic outcomes, even when implementing digital technologies in their dental offices. The use of advanced, cutting-edge digital tools does not negate the need to adhere to timeless fundamentals of esthetic dentistry. This article reviews key esthetic principles and describes their application in treating a challenging cosmetic case. Showcasing the use of smile design software, the case illustrates the diagnosis, planning, and clinical execution used to mask a congenitally missing lateral incisor while preserving the natural dentition on the contralateral side. The principles of symmetry and harmony are employed to create a smile in which the restorative dentistry would be imperceptible and the remaining dentition protected from structural compromise. [ABSTRACT FROM AUTHOR]

This study examined the correlation between maxillary anterior tooth form and gender with three-dimensional data. Three-dimensional digital models of the area between the maxillary right central incisor and the maxillary right canine were obtained from 120 Caucasian subjects (60 males and 60 females) with healthy dentitions. Correlation between gender and tooth form was assessed applying logistic regression, with and without size standardization. Success rates were estimated using 10-fold cross-validation. Principal components that correlated with gender were evaluated with a Wald test. Values for the significance of the predictors were provided with a likelihood ratio test (P < 0.05). Significant correlation between genderand tooth shape was found for the maxillary central incisor (P = 0.003), lateral incisor (P ≤ 0.001), and canine individually(P ≤ 0.001), and for the three teeth combined (P ≤ 0.001) without size standardization. For the maxillary right lateral incisor (P = 0.004), canine (P ≤ 0.001), and the combination of the teeth (P ≤ 0.001), a correlation was also established after size standardization. Prediction of genderwas not possible without information on tooth size for the maxillary right central incisor (P = 0.15). Maxillary anterior teeth have gender-specific differences. Differences in tooth size account for part of the correlation. However, tooth shapes are also gender specific. [ABSTRACT FROM AUTHOR]

Background/aims: Traumatic dental injuries are one of the most prevalent diseases globally, impacting people of different ages and socio-economic statuses. As disease prevention is preferable to management, understanding when an individual's overjet is prone to dental trauma helps identify at-risk patients, so to institute preventive strategies. The aim of this study was to identify the different overjet sizes that present an increased risk for developing dental trauma across different ages and dentition stages.Methods: The title and protocol were registered and published a priori with the Joanna Briggs Institute (JBI) and PROSPERO (CRD42017060907) and followed the JBI methodology of systematic reviews of association (etiology). A three-step search strategy was performed, including electronic searches of gray literature and four databases. Studies of healthy human participants of any age and in any dental dentition stage were considered for inclusion. Only high methodological quality studies with low risk of bias were included. Where possible, meta-analyses were performed using the random-effects model, supplemented with the fixed-effects model in situations where statistical heterogeneity was ≤50%, assessed using the I2 statistic.Results: The study identified 3718 articles, 41 were included. An increased overjet was significantly associated with higher odds of developing trauma in all dentition stages and age groups. Children 0-6 years with an overjet ≥3mm have an odds of 3.37 (95%CI, 1.36-8.38, P = 0.009) for trauma. Children in the mixed and secondary dentition with an overjet >5mm have an odds of 2.43 (95%CI, 1.34-4.42, P = 0.004). Twelve-year-old children with an overjet >5mm have an odds of 1.81 (95%CI, 1.44-2.27, P < 0.0001).Conclusions: The results confirm the association between increased overjet and dental trauma. A child in the primary dentition could be considered as having an overjet at risk for trauma when it is ≥3mm. In the early secondary dentition, the threshold for trauma is an overjet ≥5mm. [ABSTRACT FROM AUTHOR]

Paleontologists use fossil teeth to reconstruct the diets of early hominins and other extinct species. Some evidence is adaptive: nature selects for tooth size, shape, and structure best suited to specific food types. Other evidence includes traces left by actual foods eaten, such as microscopic tooth wear. This critical review considers how molars work, how they are used, and how occlusal topography and dental microwear can be used to infer diet and food preferences in the past, particularly for hominins of the Pliocene and early Pleistocene. Understanding that cheek teeth function as guides for chewing and tools for fracturing allows us to characterize aspects of occlusal form that reflect mechanical properties of foods to which a species is adapted. Living primates that often eat leaves, for example, have longer crests and more sloping occlusal surfaces than those that prefer hard foods. Studies of feeding ecology have shown, however, that tooth shape does not always correspond to preferred food items. It often follows mechanically challenging foods whether eaten often or rarely. Other lines of evidence that reflect actual tooth use are required to work out food preferences. Microwear textures, for example, reflect foods eaten by individuals in the past such that hard seeds and bone tend to leave complex, pitted surface textures, whereas tough leaves and meat more often leave anisotropic ones covered in long, parallel scratches. The study of fossil hominin molars shows how these various attributes are combined to infer diet and food preference in the past. A trend in occlusal morphology suggests decreased dietary specialization from Australopithecus to early Homo, and increasing dispersion in microwear complexity values is consistent with this. On the other hand, occlusal morphology may suggest dietary specialization in Paranthropus, although different species of this genus have different microwear texture patterns despite similar craniodental adaptations. [ABSTRACT FROM AUTHOR]

Objectives: The use of dental metrics in phylogenetic reconstructions of fossil primates assumes variation in tooth size is highly heritable. Quantitative genetic studies in humans and baboons have estimated high heritabilities for dental traits, providing a preliminary view of the variability of dental trait heritability in nonhuman primate species. To expand upon this view, the heritabilities and evolvabilities of linear dental dimensions are estimated in brown‐mantled tamarins (Saguinus fuscicollis) and rhesus macaques (Macaca mulatta). Materials and methods: Quantitative genetic analyses were performed on linear dental dimensions collected from 302 brown‐mantled tamarins and 364 rhesus macaques. Heritabilities were estimated in SOLAR using pedigrees from each population, and evolvabilities were calculated manually. Results: Tamarin heritability estimates range from 0.19 to 0.99, and 25 of 26 tamarin estimates are significantly different from zero. Macaque heritability estimates range from 0.08 to 1.00, and 25 out of 28 estimates are significantly different from zero. Discussion Dental dimensions are highly heritable in captive brown‐mantled tamarins and free‐ranging rhesus macaques. The range of heritability estimates in these populations is broadly similar to those of baboons and humans. Evolvability tends to increase with heritability, although evolvability is high relative to heritability in some dimensions. Estimating evolvability helps to contextualize differences in heritability, and the observed relationship between evolvability and heritability in dental dimensions requires further investigation. [ABSTRACT FROM AUTHOR]

The investigation conducted to evaluate the relationships between the size of teeth and carabelli’s cips from 120 students of the Favulty of Dentistry a average of age of 20 years. The data of the size teeth and the carabelli’s cups of the first permanent upper molars were optained from the upper arch printing. In addition, corresponding measure meats were also mode is the mesio-distal and bucco palatal teeth. The scores of the carabelli’s cups were based on the Dalberg’s classification. The results showed that the number of the teeth which had score I with grooves were high (48; 40%), then followed by score 0 (the average of mesio palatal cups) Which comprised of 44 teeth (20%), score 3 (there were depressions shaped as a small “Y” alphabet) were 19 teeth (15,83%), score 5 (there were small cups), score 6 (three were medium cups), score 2 *there wer pits) and score 4 (there were depression shaped as big “Y” alphabet which each comprised of 12 teeth (10%); 7 teeth (5,83%); 6 teeth (5%) and 4 teeth (3,33%). None of the teeth had carabelli’s cup with core 7 (there were cups with big size). The results of the measurements on mesio-distal and bucco palatal teeth were variable. The smallest mesio-distal and bucco-palatal teeth were 0,20 mm and the largest were 12,80 mm. In size showed that there was a significant relationship between the teeth size and carabelli’s cups which the size of carabelli’s cups was always in line the teeth size.

Objectives: To assess palatal vault height, tooth size, and dental arch dimensions in patients with unilateral and bilateral palatally displaced canines compared with a control group. Materials and Methods: A sample of 66 patients (mean age: 11.5 6 1.0 years) with 22 unilateral palatally displaced canines (UPDCs), 22 bilateral palatally displaced canines (BPDCs), and 22 controls (C) were consecutively recruited. All three groups had dental casts that were scanned digitally using the OrthoX three-dimensional model scanner. Tooth size, palatal vault height, dental arch width, dental arch depth, dental arch length, and dental arch space were measured by the same examiner using the GOM software. Remeasurements were made in 10 randomly identified patients. Results: The palatal vault height was significantly lower in the BPDC group compared with controls. A significantly smaller mesial-distal crown width and, in general, more spacing in the maxilla were found in the UPDC and BPDC groups. No differences in arch length or arch width at the molar region were seen between the groups, while the arch length at the canine region was smaller in the UPDC and BPDC groups. However, this was observed in BPDC patients with both deciduous canines present and in most UPDC patients where the deciduous canine was present, compared with the control group, who had more permanent canines present. Conclusions: Patients with PDC had greater reduction in tooth size compared with the control group. The arch length and arch width were similar in patients with and without PDC. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the tooth size discrepancy and Bolton's ratios between male and female subjects with a Class I malocclusion.Materials and Methods: The digital e-models of 100 male and 100 female 12-year-old southern Chinese children with a Class I malocclusion were selected. The mesiodistal widths from permanent first molar to the contralateral side first molar of the upper and lower dentitions were measured. Differences between the tooth size discrepancy, together with the anterior and overall Bolton's ratios between male and female subjects, were assessed using a two-sample t-test. A paired t-test was used to determine differences between antimetric pairs of teeth within the same arch.Results: Females had statistically significant smaller teeth than males (P < 0.05) except the upper left and lower left lateral incisor and lower left and right central incisors. The mean values of anterior Bolton's ratios for males and females were 77.04 and 77.03, respectively (P > 0.05), while the mean values of overall Bolton's ratios of male and female are 90.48 and 90.65, respectively (P < 0.05). The clinical significant differences (Cohen's d > 0.2) for contralateral tooth size were shown on the maxillary canines, lateral incisors, and central incisors of males; and mandibular canines and lateral incisors of females.Conclusions: Southern Chinese females presenting with Class I malocclusions have smaller mesiodistal tooth dimensions compared to males. Both males and females presented several tooth size asymmetries. There are no statistical differences in anterior and overall Bolton's ratios between the genders. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Odontometric studies of African populations show high within‐group variation in tooth size. Overall, North Africans exhibit smaller dimensions than groups from eastern and southern sub‐Saharan regions, but no previous studies have analyzed the full dental metrics among extant African Pygmy hunter‐gatherers and Bantu‐speaking farmers. Furthermore, the population variability in tooth crown sizes from equatorial rainforest regions remains to be elucidated. Materials and Methods: The mesiodistal and buccolingual diameters of the permanent teeth (I1‐M2) were measured in vivo using high‐resolution replicas from Baka Pygmies and Mvae and Yassa Bantu‐speakers from Cameroon (western Africa). Analyses of variance were used to record sex‐related and population‐level differences in tooth sizes, and a principal component analysis of geometrically scaled measures was used to plot the odontometric variability among groups. Results: Cameroonian Baka Pygmies differ in dental size from their Bantu‐speaking neighbors. Molar teeth are larger in Pygmies than in Bantu individuals, while the anterior dentition is larger in the Bantu. Baka males exhibit significantly larger teeth than females, whereas sexual dimorphism in non‐Pygmies is only present in the anterior dentition. Discussion: Odontometric patterns and the degree of sexual dimorphism in dental size differ among Central African groups, indicating adaptation to their different forager and farmer lifestyles. In particular, the admixture of Bantu‐speakers in Baka populations is smaller than that in other western Pygmy groups. The greater dental phenetic diversity in Baka compared to that of the smaller‐toothed farmers suggests that ecogenetic and microevolutionary factors are influencing a particular divergence scenario. [ABSTRACT FROM AUTHOR]

Background: Bolton's two main ratios describing the proportional size of upper and lower teeth, could contribute to estimating the excess or deficiency of tooth size necessary to obtain an ideal occlusion. However, the mean Bolton values are not the same among different societies. Determining the prevalence of tooth size deviations from population-specific Bolton indices might help local orthodontists to have a more concise treatment plan. Objective: The study aimed to define the prevalence of clinically significant tooth size discrepancies (TSD) in an Iranian population and to evaluate the influence of lateral incisors' size on this discrepancy. Methods: This cross-sectional study was conducted on study casts of orthodontic patients attending Imam Reza Dental Clinic from September 2008 to December 2016. The sample comprised of 150 randomly selected pretreatment study casts (64 males and 86 females from 17 to 28). The mesiodistal diameter of all permanent teeth from the first molar on the right to the first molar on the left was measured using 2 similar digital calipers, and Bolton analysis was calculated. Subjective visual estimation of Bolton discrepancy was also performed. SPSS v18.0, Wilcoxon signed ranks test, Pearson correlation and Receiver Operating Characteristic (ROC) curve analysis were used for statistical analysis. A p<0.05 was considered statistically significant. Results: In the sample group, 34.7% had anterior Bolton index (ABI) and 20.7% had total Bolton index (TBI) greater than 2 Standard Deviations (2SDs) of Bolton's means, and about half of them required correction of the ABI considering the actual size of discrepancies (mm). The sensitivity of estimating clinically significant tooth size discrepancy more than 2SDs of Bolton's ABI and the visual judgment was 96.0% and a cut-off point of - 0.12mm was obtained. Conclusion: Bolton's analysis should be routinely performed in all orthodontic patients, and visual estimation of TSD would be suggested as a screening method in the first visit prior to measurements and set-ups. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The objective of this study was to assess the accuracy, reliability, and reproducibility of computed tomography (CT) images in measuring cervical mesiodistal and buccolingual tooth sizes, by comparing the values obtained by 3D virtual models from CT images with those obtained using digital calipers. Materials and methods: In total, 530 maxillary and mandibular teeth of 51 individuals from two Iron Age sites were scanned using a Siemens Somatom sensation 64‐slice computed tomography machine, and the images were reconstructed and measured. Values obtained by direct measurement served as the primary reference for cervical measurements. Intra‐ and inter‐observer reliability was assessed by calculating technical error of measurements (TEM), relative technical error of measurements (rTEM), and the coefficient of reliability (R). Results: Results showed that virtual cervical measurements were not significantly different from the actual measurements, and the correlation of the two measurement methods shows that the methods are comparable. Inter‐ and intra‐observer error analysis also indicated high replicability of measurements with both measuring methods (R > 0.99). The rTEM values for all the measurements were below the 5% standards for anthropometric studies. Discussion: CT is a non‐invasive technique that allows for an accurate and detailed visualization of morphological features without causing any damage to teeth. Our findings indicate that virtual odontometric analysis is a reliable method, similar to traditional physical odontometric analysis. Currently, the virtual system is likely to be more suitable for fragile specimens, such as archaeological samples. [ABSTRACT FROM AUTHOR]

Aim: The aim of the study was to assess the anterior and overall tooth size discrepancies in different malocclusions and evaluate its effect on gender in a sample of South Telangana (Khammam) population and to compare it with Bolton standards. Materials and Methods: The study sample consisted of 311 pretreatment study casts, which were selected from records of orthodontic patients, who were residents of Khammam, South Telangana. The sample was divided into three groups based on Angle Class I, II, and III malocclusions and further subdivided into male and female groups. The mesiodistal diameters of the teeth were measured using digital calipers, and the Bolton's analysis was carried out. Statistical Analysis Used: Intraclass correlation coefficient was assessed using Dahlberg's formula. ANOVA and post hoc least significant difference test were used. Results: The mean anterior and overall ratios were 79.17 ± 2.91 and 92.3 ± 1.88, respectively. A total of 64% and 45% of the study population had tooth size discrepancies in the anterior and overall ratios when assessed for >±1 standard deviation (SD). When the sample was assessed for discrepancies >±2 SD, it was observed that a total of 33.8% and 5.5% patients had anterior and overall tooth size discrepancies. Conclusions: With significant differences being observed between Bolton's and the present study values, the need for population standards gains importance for better results at the end of orthodontic treatment. [ABSTRACT FROM AUTHOR]

Introduction: Dermatoglyphics is one of the important diagnostic tools used in the recent days for identification of an individual. Dermatoglyphics is the study of type of patterns present on digits, palms and foot. The mesiodistal diameter of the tooth is an important factor which reveals the tooth-bone discrepancy. Deciduous second molar and permanent first molar exhibit least degree of variation. Both the dermal ridges and the enamel layer of the tooth originate from ectodermal layer and during the same period of intrauterine life. Aim: To determine and compare the dermatoglyphics with the mesiodistal width of the deciduous second molar and permanent first molar. Materials and Methods: A sample of 120 child ranaged between 6-12 years were included in the study whose digital and palmer traits were recorded using ink method and the mesiodistal widths of the deciduous second molar and permanent first molar were recorded using a vernier caliper.The data was subjected to statistical analysis using unpaired t test. results: The 'ATD' angle was found in the range of 40°-50°. The loop patterns were more common followed by whorls and arch patterns. Girls expressed a greater mesiodistal diameter of deciduous second molar than boys. No significant correlation was found in between the dermatoglyphics and tooth size. conclusion: There was no significant correlation between the finger print patterns, 'ATD' angle and the mesiodistal diameter of the deciduous second molar and the permanent first molar. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of the present study was to assess differences in tooth size ratio between male and female patients reporting to Orthodontic Department at Bhitai Dental Hospital, Mirpurkhas, Sindh. The study was carried out on 150 (75 males, 75 females) study casts. Criteria for selection of the study casts were pretreatment orthodontic casts with Angle Class I and fully erupted permanent teeth with no dental anomalies. The individual mesiodistal tooth size was measured with a Boley's gauge. The mean and standard deviation was calculated for the size of the teeth and the interarch tooth width ratios both anterior and overall. The ratios for the tooth size were compared to the original Bolton ratio. The overall ratio was found to be 91.61almost equivalent to the original Bolton ratio of 91.3, whereas the anterior ratio was found to be 79.70, higher than the 77.1 as calculated by Bolton. The mean values for the overall and anterior ratio for the male and female subjects determined which significant. Standard deviations for overall were not statistically & anterior ratio were larger than the Boltons value. There were no significant differences between the mean overall and anterior tooth width ratio of males and females. Even though the values were not significantly high, a careful analysis of interarch tooth size relationship (Bolton's ratio) should be added along with other diagnostic considerations before initiating orthodontic treatment for better finishing and stability. [ABSTRACT FROM AUTHOR]

Present study was aimed to investigate the frequency of anterior tooth size discrepancy in Angle's class I and class II malocclusion groups seen at Bahria University, Karachi. Male and female subjects were randomly selected and assigned to two dental malocclusion groups according to Angle's classification class I, and II. Total number of subjects were 108 (55casts of Angle's Class I and 53 casts of Class II malocclusion). Sampling technique was non-probability, purposive type with anterior permanent teeth erupted in the upper and lower arches. The width of each tooth was measured from its mesial contact point to its distal contact point at its greatest interproximal distance. Bolton's anterior (canine to the canine) ratios were calculated. Gender distribution was 29 males and 78 female with mean anterior ratio of class I (mean = 2.33) and class II (mean = 2.51) On comparison of anterior ratio no significant difference was found between class I and class II malocclusion groups which was indicated by the p value (p = 0.565). The use of the actual millimeters of correction for the tooth size ratios could help orthodontists avoid underestimating the prevalence of clinically significant tooth size discrepancy. [ABSTRACT FROM AUTHOR]

In the field of forensic dentistry, methods for personal identification through tooth measurement have been developed. This study aimed at proposing a new method for personal identification using digital periapical radiograph. Seven measurements were performed in 206 digital periapical radiographs (103 patients with age more than 14 years old have double radiographs in the same region of interest) from seven reference distanceswhich were appointed before the measurement in permanent mandibular second premolar and first molar. The measurement process was done in two ways, digital radiography software andmanual measurement. The reliability of seven reference points was assessed with intra-observer and inter-observer values (TEM < 1 mm). The accuracy of tooth measurement method was assessed withBland- Altman test that demonstrated no statistical difference(p> 0.050) regarding paired radiograph comparison. Limits of agreement (LOA) values from Bland-Altman test showed range of difference (mm) from paired radiograph whichwas still acceptable as same person. The method been examined further through blind test for similarview radiographs resulted 100% match between one pair radiograph with true identity came from thesame person. The method proposed in this study is able to identify person accurately. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to determine if Bolton's tooth size ratios can be applied to Mediterranean, Japanese and Japanese-Brazilian populations. Materials and methods: The sample comprised 90 pairs of dental casts of untreated individuals with normal occlusion, divided into 3 groups according to ethnical characteristics: White (30 Mediterranean descendant subjects, with a mean age of 13.64 years), Japanese (30 subjects with Japanese ancestry, with a mean age of 15.63 years) and Japanese-Brazilian (30 Japanese-Brazilian subjects, with a mean age of 13.96 years). A digital caliper was used to measure the maxillary and mandibular mesiodistal widths from first molar to first molar on each dental cast. The anterior and overall tooth size ratios were calculated. T test was applied for comparisons between Bolton standards and the ethnical groups for anterior and overall ratios. Results: Only the Japanese-Brazilian group showed significantly greater ratios than Bolton standards. Conclusion: It was concluded that Bolton's ratios are not applicable to the Japanese-Brazilian population. Therefore, it is suggested that Bolton's ratios may not be suitable for different populations. [ABSTRACT FROM AUTHOR]

Introduction: Determination of gender by anthropologists can be done by various methods e.g. skull bones, pelvic bones and other skeletal determinants. Assessment of odontometric data is a promising tool for gender prediction, which is usually preserved due to its robust nature. Aim and Objectives: The objective of the study was to predict the gender of an individual, using the odontometric data with powerful statistical tools like Logistic Regression Analysis (LRA) and Discriminant Analysis (DA). Materials & Method: 100 subjects were selected (50 male and 50 female) within the age group of 18-28 years. An alginate impression was made and models were prepared. The odontometric data was collected in the form of various mesiodistal and buccolingual measurements with Vernier calipers which was subjected to statistical analysis, using the two tests LRA and DA. Thereafter, results were compared for accurate gender prediction. Results: The statistical analysis of the measurements obtained was done by using two tests logistic regression analysis and discriminant analysis. After analysis and comparisons of the two methods for gender prediction, it was observed that LRA provides more accurate prediction than DA in determining the gender. Also, when data from both the arches was analyzed, it was more accurate in predicting the gender as in comparison to the analysis from either of the arch. Conclusion: The study has revealed that LRA may be better than DA for odontometric sex prediction. Overall, the results depict that the complete dentition, when used as a unit and through the application of flexible multivariate statistics such as LRA, has potential for its use as a prominent and sole indicator of sex prediction. [ABSTRACT FROM AUTHOR]

Aim and Objectives: Tooth size prediction values are not universal for all ethnic and racial groups. The present study evaluated the applicability of Moyer's mixed dentition space analysis in the Marwari community of Rajasthan, India. Materials and Methods: The mesiodistal dimension of permanent mandibular incisors, maxillary and mandibular canine, and premolars of both sides were measured and averaged in 200 adolescents (100 males and 100 females) of the Marwari population in Rajasthan using digital Vernier caliper. Data were statistically analyzed using Student's t-test. The data were then compared with Moyer's predicted values. The tooth measurements of male and female participants were compared with unpaired t-test. Results: Moyer's prediction chart was not comparable with the study population group. The coefficient of correlation and coefficient of determination in our study was 0.57 and 0.25, respectively. Mesiodistal width of measured teeth was lesser in females compared to males for both canine and premolars ( P = 0.471 and P = 0.0001, respectively). Conclusion: There was significant statistical difference between values of the present study and Moyer's prediction values. Hence, new regression equation and prediction table can be used to predict mesiodistal dimensions of canine and premolars in Marwari children of Rajasthan. [ABSTRACT FROM AUTHOR]

Variations in the dental crown form are widely studied to interpret evolutionary changes in primates as well as to assess affinities among human archeological populations. Compared to external metrics of dental crown size and shape, variables including the internal structures such as enamel thickness, tissue proportions, and the three-dimensional shape of enamel-dentin junction (EDJ), have been described as powerful measurements to study taxonomy, phylogenetic relationships, dietary, and/or developmental patterns. In addition to providing good estimate of phenotypic distances within/across archeological samples, these internal tooth variables may help to understand phylogenetic, functional, and developmental underlying causes of variation. In this study, a high resolution microtomographic-based record of upper permanent second molars from 20 Neolithic individuals of the necropolis of Gurgy (France) was applied to evaluate the intrasite phenotypic variation in crown tissue proportions, thickness and distribution of enamel, and EDJ shape. The study aims to compare interindividual dental variations with burial practices and chronocultural parameters, and suggest underlying causes of these dental variations. From the non-invasive characterization of internal tooth structure, differences have been found between individuals buried in pits with alcove and those buried in pits with container and pits with wattling. Additionally, individuals from early and recent phases of the necropolis have been distinguished from those of the principal phase from their crown tissue proportions and EDJ shape. The results suggest that the internal tooth structure may be a reliable proxy to track groups sharing similar chronocultural and burial practices. In particular, from the EDJ shape analysis, individuals buried in an alcove shared a reduction of the distolingual dentin horn tip (corresponding to the hypocone). Environmental, developmental and/or functional underlying causes might be suggested for the origin of phenotypic differences shared by these individuals buried in alcoves. [ABSTRACT FROM AUTHOR]

Aims and Objectives: Attainment of ideal occlusion is often restricted by disproportionate sizes of individual teeth, which is otherwise termed as tooth size discrepancy (TSD). While extraction of teeth for orthodontic purposes is not uncommon, there is considerable resistance against this school of thought. The extraction of premolars, in particular, received considerable attention because of the potential TSD that could result following the extraction of premolars. The aim of the present study was to identify the consequence of premolar extractions on Bolton's overall ratios in South Indian population. Materials and Methods: One hundred participants were recruited into the study through purposive nonproportionate quota sampling. Pretreatment dental casts of the study participants were measured for mesiodistal tooth widths to determine Bolton's overall ratio before the hypothetical tooth extractions were performed. The hypothetical extractions were executed in four different combinations as follows: (a) Maxillary and mandibular first premolars, (b) maxillary first premolars and mandibular second premolars, (c) maxillary second premolars and mandibular first premolars, and (d) maxillary and mandibular second premolars. Bolton's overall ratios were calculated after the hypothetical tooth extractions were performed. Statistical analysis was done using the Statistical Package for the Social Sciences, version 20 software. Results: It was observed that extractions performed in any of the combinations followed in this study resulted in a decrease of overall Bolton's ratios. However, the discrepancy in tooth size was highest with the extraction of all first premolars, whereas least discrepancy was recorded with all second premolars extraction. It was also found that, based on the combination of teeth chosen for extraction, there was significant difference in Bolton's overall ratios between males and females. Conclusion: In formulating a treatment plan involving premolar extraction, significant tooth size discrepancies could change mutually after extraction. [ABSTRACT FROM AUTHOR]

Thanks to advances in restorative materials and adhesive techniques, several treatment options are currently available to restore anterior teeth that are not harmonious in color, shape, or size, or that have a diastema. Orthodontic and restorative therapies are routinely employed to close diastemas. Regardless of the technique used to solve this esthetic problem, the ultimate goal is always to achieve a more pleasing and natural smile. This article reports a case in which the midline diastema was successfully closed using indirect composite resin restorations and highlights the advantages of this restorative approach. [ABSTRACT FROM AUTHOR]

Objectives: To determine the occurrence of smile line and maxillary tooth shape in the Saudi Arabian subpopulation, and to estimate the association between these parameters with gingival biotype. Materials and Methods: On the fulfillment of selection criteria, total 315 patients belong to Saudi Arabian ethnic group were randomly selected. Two frontal photographs of the patients were acquired. The tooth morphology, gingival angle, and smile line classification were determined with ImageJ image analyzing software. The gingival biotype was assessed by probe transparency method. The obtained data were analyzed with SPSS 19 (IBM Corporation, New York, USA) software to determine the frequency and association between other parameters and gingival biotype. Results: Among the clinical parameters evaluated, the tapering tooth morphology (56.8%), thick gingival biotype (53%), and average smile line (57.5%) was more prevalent. The statistically significant association was found between thick gingival biotype and the square tooth, high smile line. The high gingival angle was associated with thin gingival biotype. Conclusions: The study results indicate the existence of an association between tooth shape, smile line, and gingival angle with gingival biotype. [ABSTRACT FROM AUTHOR]

Although digital technologies play an increasingly integral role in dentistry, there remains a need for dental professionals to understand the fundamentals of tooth anatomy, form, occlusion, and color science. In this article, the size, shape, composition, and appearance of maxillary anterior teeth will be discussed from esthetic and functional perspectives. A total of 600 extracted maxillary incisors were studied: 200 each of central incisors, lateral incisors, and cuspids. The purpose of the article is to exhibit and discuss factors that make teeth unique and diverse. Understanding these aspects of teeth aids dental professionals in more effectively creating realistic and highly esthetic restorations for patients. [ABSTRACT FROM AUTHOR]

Background: Natural catastrophes account for maximum and most undesirable loss of mankind. Those individuals can be best represented by dental remnants. Body size is probably the single most important determinant of body architecture, physiology ecology, life history, and social organization in mammals. The weight and body mass index (BMI) can be used as a measure of body size. It is seen that the tooth crown area (crown length multiplied by crown width) increases in relation to the square of a linear dimension, whereas body weight, being proportional to volume, increases in relation to the cube of a linear dimension, assuming geometric similarity is maintained. Thus, one might predict theoretically that tooth area should increase or decrease as the 2/3 (or 0.67) power of body weight. BMI can be calculated from body weight and height of an individual. In this study, we tried to examine the relationship between tooth crown area and body weight and BMI of human individuals. To correlate the relationship of tooth crown area with body weight and BMI of human beings. Materials and Methods: Study includes 60 individuals (30 males and 30 females) of 18-24 years of age group. Tooth crown area will be calculated as mesial-distal crown length multiplied by buccallingual width (L × W). Weight of individual will be recorded in grams. Height of individual will be recorded in centimeters. BMI will be calculated. Tooth crown area will be correlated with body weight and BMI. Results: A positive relationship between total crown area and body weight as well total crown area and BMI was observed. Conclusion: Tooth size and body size can be correlated in living human individuals. One can use the tooth crown area to predict the weight and BMI of an individual. [ABSTRACT FROM AUTHOR]

The development of pierce-feeding and loss of oral processing represented major adaptations for underwater feeding in marine mammals. We examined the evolution of pierce-feeding and its association with changes in tooth spacing and tooth size to determine whether pierce-feeding was practiced by the earliest known pinnipeds. Data on crown size and spacing in postcanine dentition were collected and 1) analysed by principal components analysis ( PCA) to determine the tooth morphospace of arctoid carnivores, 2) analysed by least squares ( LS) regression and phylogenetic independent contrasts ( PIC) to determine what morphological variables were associated with increases in tooth spacing, and 3) used to reconstruct the evolution of feeding related traits within a phylogenetic context. The PCA analysis revealed that within arctoid carnivores, the greatest differences in morphospace were associated with pierce-feeding, and the early-diverging seal Enaliarctos was placed within the pinniped morphospace. Increased tooth spacing within Pinnipedia is a result of decreased postcanine crown size. When the evolution of dental characters is reconstructed, 'enaliarctines' were found to represent an intermediate stage in evolution between 'fissiped' and pinniped carnivores. They retained the limited tooth spacing of terrestrial carnivores, possessed postcanine crown lengths intermediate in size between pinnipeds and fissipeds, and possessed reduced heterodonty characteristic of crown pinnipeds. Our study indicated that pierce-feeding evolved early within pinnipeds. This suggested either that pierce-feeding evolved prior to the loss of mastication, or that pierce-feeding evolved at the same time as loss of mastication, and well before simplification of the dentition was completed. [ABSTRACT FROM AUTHOR]

When dealing with excessive gingival display it is important for the treating clinician to properly identify the etiology, as potential etiologic factors can vary widely. Treatment decisions in this case involving a patient with high lip dynamics and a "gummy smile" were complicated because treatment recommendations differed for each of the several etiologies involved. The treatment performed, which included orthodontics combined with crown lengthening and in which the final restorations were segmented anterior to posterior to give both the clinician and laboratory improved control, was designed to meet the patient's desired esthetic outcome while addressing the areas of risk established in the preoperative assessment. [ABSTRACT FROM AUTHOR]

Treating patients with "gummy smiles" and improving smile esthetics has become an integral part of dentistry. It is necessary to conduct an accurate diagnosis of what may be multiple causes that coexist simultaneously. Though all causes may not be resolved following treatment, they should be identified; otherwise it might not be possible to conduct an adequate order of treatment, which could involve multidisciplinary collaboration between various dental specialists, and may lead to unexpected and unacceptable final results. The authors propose a complete adult classification of the causes identified for gummy smile (GS) and short tooth syndrome (STS) to ascertain the etiopathogenetic origin(s). Used in combination with the proposed diagnostic procedure, which involves an "outside-in" evaluation of the patient, the classification system will enable clinicians to provide patients an accurate prediction of final results and determine the treatment required. [ABSTRACT FROM AUTHOR]

Introduction: The compliance of proportions between the mesiodistal dimensions of the upper and the lower teeth is necessary for good intercuspidation. Given that a significant discrepancy in tooth size can prevent ideal occlusion at the end of orthodontic treatment, the absence of tooth size discrepancy is a significant factor for the realization of the ideal occlusion. The aim: Aim of this study was to determine whether there is a difference in the incidence of tooth size discrepancies among different skeletal malocclusion groups in the orthodontic patients. Material and methods: The sample comprised 300 pretreatment study casts (118 males and 182 females) with fully erupted and complete permanent dentition except third molars, which were selected randomly from records of orthodontic patients. All subjects were divided in three groups, according to the Angle classification of malocclusion. The measurements were made on study models with digital calipers accurately to 0.01 mm. The Class was defined by using the Steiner analysis on lateral cephalograms.The subjects were divided into three groups depending on the value of the ANB angle. For every subject, the value of the angles SNA, SNB and ANB was measured. The reliability of measurements was examined by the Pearson's correlation coefficient. To determine whether there were gender differences an independent sample t-test was performed. Results: There is no statistically significant differences in Bolton's discrepancy by different gender, or at different classes. The average value of the anterior Bolton ratio was 78.16 and of the overall were 90.87. Values of the anterior and overall Bolton ratios are highest in patients with Class III. The highest average value of anterior discrepancy was in male subjects with III Class (-0.72), while the highest average value of overall discrepancy was in male subjects with II Class (0.65). Conclusion: The results of the study show that there are no statistically significant differences in Bolton's discrepancy by different gender, or at different classes. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to investigate the prevalence of selected dental variations in association with infraocclusion, as well as determining the effects of infraocclusion on dental development and tooth size, in singletons and twins. Design Two samples were analysed. The first sample comprised 1454 panoramic radiographs of singleton boys and girls aged 8–11 years. The second sample comprised dental models of 202 pairs of monozygotic and dizygotic twins aged 8–11 years. Adobe Photoshop CS5 was used to construct reference lines and measure the extent of infraocclusion (in mm) of primary molars on the panoramic radiographs and on 2D images obtained from the dental models. The panoramic radiographs were examined for the presence of selected dental variations and to assess dental development following the Demirjian and Willems systems. The twins’ dental models were measured to assess mesiodistal crown widths. Results In the singleton sample there was a significant association of canines in an altered position during eruption and the lateral incisor complex (agenesis and/or small tooth size) with infraocclusion ( P < 0.001), but there was no significant association between infraocclusion and agenesis of premolars. Dental age assessment revealed that dental development was delayed in individuals with infraocclusion compared to controls. The primary mandibular canines were significantly smaller in size in the infraoccluded group ( P < 0.05). Conclusion The presence of other dental variations in association with infraocclusion, as well as delayed dental development and reduced tooth size, suggests the presence of a pleiotropic effect. The underlying aetiological factors may be genetic and/or epigenetic. [ABSTRACT FROM AUTHOR]

Objective The associations seen clinically between variations in tooth number, size and shape reflect the repetitive genetic interactions occurring between the epithelium and mesenchyme during the initiation and morphogenetic stages of the Complex Adaptive System that is dental development. The aim of this study was to investigate the clinical relationship further by comparing multiple crown parameters, including cusp numbers, between patients with mild hypodontia and controls in a Romanian sample. Design Digital images of dental casts of the permanent dentition from 28 patients with mild hypodontia and 28 controls were used. Measurements from the vestibular and occlusal surfaces were performed using a 2D image analysis method and cusps, including the Carabelli trait, were counted. Two-way analysis of variance was performed. Results The dimensions of the mild hypodontia group had smaller values than the controls, with many measurements being significantly different (significance values varied from p = 0.049 to p = 0.001 ). The most affected regions were the upper and lower anterior region in both sexes. Mesio-distal, bucco-lingual and occlusal area and perimeter dimensions were affected. Females from the hypodontia group had significantly less tricuspidated lower premolars when compared with the control group. Carabelli cusps were present in the hypodontia group less frequently, the difference being highly significant ( p = 0.0002 ) in women. Conclusions The hypodontia patients presented with reduced crown dimensions and shape compared with controls. This is the first published study to demonstrate smaller cusp numbers in patients with hypodontia than in controls. The findings are compatible with a model of dental development as a Complex Adaptive System incorporating associations between tooth number, size and shape. [ABSTRACT FROM AUTHOR]

Aim: The aim of the present study was to evaluation and comparison of intermaxillary tooth size discrepancy among Class I, Class II division 1, and Class III subjects using Bolton's analysis. Materials and Methods: The pre-treatment casts were selected from the records of patients attending the Department of Orthodontics of Meenakshi Ammal Dental College, Chennai. The sample consists of 180 pre-treatment casts with both sexes evenly distributed with 60 casts in each type of malocclusion, i.e., Class I, Class II div 1, and Class III malocclusion. The sample was selected according to angles classification. All patients were Indian nationals, between the age group of 12 to 20 years and Bolton's analysis done on all the casts. Results: Statistically no significant difference in all types of malocclusion except anterior Bolton's discrepancy in Class III. Conclusion: Mean Bolton's anterior ratiofor angles Class III subjects was significantly greater than for Class I and Class II subjects. When Bolton's overall ratio was compared there was no statistically significant difference among Class I, Class II div 1, and Class III malocclusions. [ABSTRACT FROM AUTHOR]

Apart from reflecting modern human dental variation, differences in dental size among populations provide a means for studying continuous evolutionary processes and their mechanisms. Dental wear, on the other hand, has been widely used to infer dietary adaptations and variability among or within diverse ancient human populations. Few such studies have focused on modern foragers and farmers, however, and diverse methods have been used. This research aimed to apply a single, standardized, and systematic quantitative procedure to measure dental size and dentin exposure in order to analyze differences among several hunter-gatherer and agricultural populations from various environments and geographic origins. In particular, we focused on sexual dimorphism and intergroup differences in the upper and lower first molars. Results indicated no sexual dimorphism in molar size and wear within the studied populations. Despite the great ethnographic variation in subsistence strategies among these populations, our findings suggest that differences in sexual division of labor do not affect dietary wear patterns. [ABSTRACT FROM AUTHOR]

Increase in the size of gingiva referred to as "gingival enlargement," usually overfills the interproximal spaces, ballooning out over the teeth and sometimes even protruding into the oral cavity. It may occur as localized enlargement in relation to a single tooth, a group of teeth, or may be generalized involving the entire dentition. It is multifactorial in origin having the influence of bacterial plaque, systemic factors or conditions, genetic predisposition (hereditary or familial), and various medications. Sometimes, it may appear as diffuse enlargement of gingiva without any specific etiologic factor. It is then considered as idiopathic enlargement. In this case report, an idiopathic gingival enlargement was successfully treated using gingivectomy by ledge and wedge procedure. The surgical technique performed yielded functionally as well as esthetically satisfying results. Gingivectomy provides a viable option to manage diffuse enlargement cases. This procedure provides the functional as well as esthetic demands and at the same time, it maintains the integrity of periodontium. [ABSTRACT FROM AUTHOR]

Background: For proper intercuspation, the teeth must be proportional in size. If teeth are mismatched, with unusually large teeth in one arch compared to the other, then an ideal occlusion cannot be attained. This study has been done to determine the prevalence of tooth size discrepancies among orthodontic patients in general and also between different malocclusion groups, sex, and to analyze the change in the degree of severity in Bolton discrepancy before and after the hypothetical premolar extraction. Methods: The study was carried out on randomly collected 100 pre-treatment dental casts. Tooth size analyses were performed on these pre-treatment models and Mesio distal tooth size ratios were measured as described by Bolton before and after various patterns of hypothetical extraction. Result: The results were statistically evaluated using ANOVA and paired samples t-test. 5 out of 100 patients are seen with severe Bolton discrepancy with Bolton values (BV) ranging above and below 2 standard deviation. Statistically insignificant difference is seen between males and females and also between various groups of malocclusion. The difference between the pre-treatment and post extraction BV was found statistically significant for the first premolar extraction and insignificant for others. Conclusion: The results of this study indicate a new point of view to the question of which teeth to extract when evaluated for tooth size aspect only. [ABSTRACT FROM AUTHOR]

The main goal in comprehensive orthodontic treatment is to obtain an optimal functional occlusion, overbite and overjet. Tooth size discrepancies of the maxillary and the mandibular arches are an important factor for achieving this goal. Inadequate relationships between the maxillary and the mandibular teeth can pose problems in achieving the ideal occlusion. Early treatment planning and proper diagnosis of tooth size discrepancy minimizes problems attained at finishing stage. Bolton's ratios set an ideal relationship of maxillary tooth width to mandibular tooth width. This article shows the significance, validity as a diagnostic tool and the methods of measuring tooth size discrepancy. [ABSTRACT FROM AUTHOR]

Previous analyses of dental size in Gigantopithecus blacki indicated marked sexual dimorphism and a trend towards increasing size through time. These studies were based on a sample of over 700 teeth from five localities excavated prior to 1990. Since then, 12 additional cave sites have been discovered in southern China, yielding hundreds of isolated teeth of G . blacki . Most of these sites are well dated by a combination of biochronology and absolute dating methods, so we now have a much better understanding of the chronology of G . blacki . Here, we reexamine the degree of sexual dimorphism and the question of dental size increase through time in G . blacki based on the expanded collections now available. Our results show that sexual dimorphism is not as marked as indicated in previous studies and confirm earlier analyses suggesting that the postcanine teeth of G. blacki tend to become larger through time from the beginning of the Early Pleistocene to the Middle Pleistocene. [ABSTRACT FROM AUTHOR]

Background Many difficulties encountered during the finishing-phase of orthodontic treatment arise due to lack of intermaxillary tooth-size matching. Bolton ratio is one of the most useful calculations for precise orthodontic diagnosis as it shows whether a correct ratio between dental proportions exists or not. Objectives To determine the mesiodistal tooth width in anterior and overall Bolton ratios in normal occlusion and different malocclusion groups in a Sudanese sample and compare to Bolton's standard. Materials and methods The sample consisted of 196 (86 male and 110 female) study models with normal occlusion, Class I, II and III malocclusions, and the age of subject 17–20 years old. Tooth size measurements were performed by electronic digital calipers. Tooth size ratios were analyzed as described by Bolton. The incidence of mesiodistal tooth size discrepancies in the malocclusion groups was analyzed and compared between male and female. The anterior and overall ratios were compared with the ratios Bolton's study. Results No significant difference in the anterior and overall ratios of normal occlusion sample when compared to Bolton's standard. No significant differences were found among gender. ANOVA indicated that no significant difference was determined in the anterior and overall ratios in different malocclusion groups. Conclusion Bolton's values can be used for Sudanese population until a large representative sample is studied. [ABSTRACT FROM AUTHOR]

Introduction This study compared the amount of hard tissue debris produced after different apical enlargement with single-file reciprocating systems (WaveOne [Dentsply Maillefer, Baillaigues, Switzerland] and Reciproc [VDW, Munich, Germany]) and a conventional multifile rotary system (BioRaCe [FKG Dentaire, La-Chaux-de-Fonds, Switzerland]) using micro–computed tomographic imaging. Methods Thirty moderately curved mesial roots of mandibular molars presenting 2 independent root canals were selected and scanned at an isotropic resolution of 14.16 μm. The sample was assigned to 3 groups ( n = 10) with respect to the root length and degree of curvature of the mesial root according to the system used for the root canal preparation: Reciproc, WaveOne, and BioRaCe. Second and third scans were taken after the root canals were prepared up to ISO sizes 25 and 40, respectively. The matched images of the mesial canals, before and after preparation, were examined from the furcation level to the apex to evaluate the amount of hard tissue debris (%). Data were statistically compared using a general linear model for repeated-measures with a significance level set at 5%. Results Instrumentation systems per se did not influence the amount of hard tissue accumulation ( P > .05), whereas a significant reduction in the percentage of hard tissue debris was observed after sequential enlargement in all groups ( P < .05). Conclusions None of the systems yielded root canals completely free from packed hard tissue debris. The increased final apical size resulted in significantly less debris accumulation for both reciprocating and rotary systems. [ABSTRACT FROM AUTHOR]

Introduction: The aims of the study were; to evaluate the applicability of the Moyers and Tanaka-Johnston Methods to individuals with a Spanish ancestry, to propose new regression equations using the lower four permanents incisors as predictors for the sum of the widths of the lower permanent canine and premolars, and to compare the new data to those from other populations. Methods: A total of 359 Spanish ancestry adolescents were selected. Their dental casts were measured using a 2D computerized system. Real teeth measurements were compared with those predicted using Moyers probability tables and Tanaka and Johnston equations, and standard regression equations were then developed. Results: Results showed that Upper and Lower Canine and Premolar (UCPM, LCPM) predictions are quite different depending on the used method. Moyers tables can only be validly applied to a 75% percentile for the mandible in both, males and females, 85% in males and 90-92% in females. Conclusions: Moyers predictions tend to underestimate UCPM and LCPM whereas Tanaka-Johnston predictions tend to overestimate them. Equations for estimating the combined width of the unerupted canine and premolars were; Male: UCPM = 12.68 + 0.42 LI and LCPM = 11.71 + 0.44 LI. Female: UCPM = 12.06 + 0.43LI and LCPM = 10.71 + 0.46 LI. [ABSTRACT FROM AUTHOR]

The evolutionary trends of tooth size in quaternary carnivores support an almost direct association with climate. However, phenotypic trait may follow distinct tempo and mode of evolution such as Brownian, Ornstein–Uhlenbeck or random walk. Here, we investigated the morphometric variations and evolutionary trends in the carnassial teeth size of the European wolf ( Canis lupus ) by means of modern statistical tools. Recent contributions highlighted linear increase trend in tooth size through the Pleistocene, but those differences in time have not been tested using modern statistical strategies. Examining a wide sample of linear measurements of carnassials of extinct and extant wolves (486 M 1 and 491 P 4 ), we tested which evolutionary model (random walk, stasis, Ornstein–Uhlenbeck) better explains the dimensional pattern of teeth through time at the continental scale and at the regional scale (France and Italy). Our results clearly show different models for the carnassials of C . lupus . Lower and upper carnassials for the entire sample of C . lupus are characterized by a directional trend, whereas Italian and French subsets show a random fluctuation of carnassials size through time. The carnassials dimensions are not directly correlated with the climate changes during the Middle–Late Pleistocene and Holocene, but they are possibly correlated with spread of the cold mega-fauna in Europe, and thus with the changes in the dietary regime. [ABSTRACT FROM AUTHOR]

Objective. Electronic apical foramen locators are now widely used to determine working length. This study was designed to determine whether tooth length influenced the accuracy of the Root ZX device. Materials and methods. Forty extracted maxillary canine teeth with a length range of 27-29 mm were selected. Access cavities were prepared and coronal flaring of canals performed. The teeth were mounted in self-polymerizing acrylic resin to facilitate horizontal sectioning except for the apical 3-4-mm portion of the root and embedded in alginate as the electronic medium. Electronic measurements were taken at the major foramen, 'zero' reading using the Root ZX and compared with the actual root canal length. The teeth were sectioned 3 mm from the coronal reference point to create a second group with shorter length; these reductions in the length continued six times in all to create seven groups of 40 specimens each. The actual and electronic lengths of specimens in each group were measured. Data were analyzed by Pearson's correlation coefficient. Results. Identical measurements between the actual and electronic root canal length from the longest to the shortest groups were 12.5%, 10.0%, 20.0%, 27.5%, 37.5%, 35.0% and 45.0%, respectively. There was a mild negative correlation between the precise measurements of the Root ZX and root canal lengths in the seven groups ( r = −0.964, p < 0.001). Conclusion. Under the conditions of the study, the Root ZX device was more accurate in shorter teeth compared to longer ones. [ABSTRACT FROM AUTHOR]

Background: To compare the variation in size of left and right maxillary central incisors for male patients (using digital calipers of 0.01 mm accuracy). To compare the variation in size of left and right maxillary central incisors for female patients (using digital calipers of 0.01 mm accuracy). To find out the difference between the maxillary central incisors of men and women. Its clinical applicability if difference exists. Materials and Methods: A total of 70 dental students of PMNM Dental College and Hospital were selected. Of 70 dental students, 40 male and 30 female were selected. Impressions were made for all subjects, using irreversible hydrocolloid (Algitex, manufacturer DPI, Batch-T-8804) using perforated stock metal trays. The mesiodistal crown width and cervical width were measured for each incisor and recorded separately for left and right teeth. The length was measured for each incisor and recorded separately for left and right maxillary central incisor using digitec height caliper. Results: The mean value of maximum crown length of maxillary left central incisor of male was greater in length compared with maxillary right central incisor. Mean value of maximum crown length for male patient right and left side was greater compared with maximum crown length of female patient. Conclusion: When compared the dimensions of teeth between two sex, male group shows larger values to female group. [ABSTRACT FROM AUTHOR]

Objective. Previous results regarding human sex chromosome aneuploidies have shown that the X and Y chromosomes affect tooth size and morphology. This study looked for the effect of sex chromosome deficiency on permanent tooth crown heights. Materials and methods. The material, from the Finnish KVANTTI Research Project, consisted of 97 45,X females and 15 45,X/46,XX females. The controls were 32 sisters and 28 mothers of the 45,X females, eight sisters and two mothers of the 45,X/46,XX females and 35 female population controls. Crown heights of all the available teeth except third molars on both sides of the jaws were measured from panoramic radiographs with a digital calliper according to the defined procedure. Results. The tooth crown heights were significantly smaller in the 45,X females than in the female population controls, except for the incisors and one canine in the maxilla, whereas the tooth crown heights of the 45,X/46,XX females were close to those of the normal control females. The differences between the 45,X and 45,X/46,XX females were statistically significant, excluding the upper incisor area and a few teeth in the mandible. Conclusions. The effect of the sex chromosome deficiency on permanent tooth crown height is due to the magnitude of lacking sex chromosome material. The present results regarding the 45,X females are parallel to previous findings in Turner patients regarding reduced mesiodistal and labiolingual dimensions and tooth crown heights in the permanent dentition. [ABSTRACT FROM AUTHOR]

Objective. The prime aim of the study was to measure and compare the 3D CBCT Bolton tooth size ratio in relation to the upper and lower arch widths, arch length and arch perimeter. Materials and methods. The data source was CBCT high volumetric data from the archives. Tooth size, arch widths, arch length and arch perimeter were measured in maxilla and mandibular arches. The independent t-test and ANOVA were used for statistical analyses. Results. The female Bolton anterior ratio (BAR) (78.373) and Bolton overall ratio (BOR) (93.231) show a greater tooth size ratio in comparison to male BAR (77.162) and BOR (93.124), respectively. However, no significant difference was found in the sexual comparison of all the measurements. Tooth size ratio in arch width groups also showed no significant difference. Significant discrepancies in the arch length ( p < 0.05) groups and overall ratio and in the arch perimeter groups ( p < 0.05 and p < 0.01) and anterior ratio were revealed. Conclusions. Tooth size ratios during orthodontic treatment for different arch length and arch perimeter groups need to be evaluated carefully. [ABSTRACT FROM AUTHOR]