Mesiodistal Crown Dimensions Research Articles

Comparative Study of Mesiodistal Crown Dimensions and Tooth Size Discrepancies of Thalassemia and Control Iraqi Patients

Aims: To find differences in mesiodistal tooth width in Iraqi B thalassemia compared with normal individuals. Setting and design: 44 subjects, 22 thalassemia (11 males, 11 females) (12.5–22) years, and 22 control (11 males, 11 females) 14–23 years. Methods and Material: Registrations of MD for maxillary and mandibular teeth from the first molar on one side to analogous tooth on the other side were done. Statistical analysis: Mean, standard deviation and 2-sampled t-test were used. Results: In both groups, males’ crown size was greater than females. In the study group largest gender variances appear in the maxillary molars, mandibular molar, maxillary central and maxillary canine respectively. In control, the greatest sexual difference is present in the maxillary first premolar followed by the mandibular second premolar. The means of mesiodistal in both sexes in thalassemia were smaller than in control except in male maxillary central and lateral and female maxillary lateral incisor. In the maxilla, a significant decrease in mesiodistal thalassemia is present in canine and second premolar in both sexes. In the mandible, a significant decrease in thalassemia was present in all comparisons in both genders in comparison with the control. The greatest mesiodistal difference in the mandibular male is present in the first molar, first premolar, second premolar, canine, lateral and central incisor respectively. In female mandibular teeth, the greatest difference is present in the first molar followed by the first premolar, second premolar, canine, lateral incisor and central incisor. Conclusions: Means mesiodistal dimensions in thalassemia show a significant reduction in mandibular teeth and maxillary canine and second premolar in both genders.

Comparison between Digital Panoramic Radiography and Cone-Beam Computed Tomography in Measuring Presurgical Dental Implant Vertical Height at Posterior Mandible

Objectives: This study aims to evaluate the reliability of panoramic radiograph in comparison to cone beam computed tomography for posterior mandibular pre-implant assessment. Materials and Methods: A retrospective evaluation of the panoramic (PAN) and CBCT images in complete, partially edentulous, and dentate patients was conducted on 66 cases for presurgical dental implant assessment. Assessment of the vertical bone height was conducted by dividing the posterior mandible region into anterior (first premolars to second premolars) and posterior (first molars to second molars) segments. The average mesiodistal crown dimensions from each segment were measured as a midpoint. The reference point to measure the vertical bone height was established from the alveolar crest to the superior border of mandibular canal. Therefore, the measurement will begin at the midpoint of total mesiodistal crown dimension of each segment from the alveolar crest to the superior border of mandibular canal. All measurements were independently performed by two observers thrice on each modality. Results: A paired comparison between PAN and CBCT images in measuring the presurgical dental implant vertical height from alveolar crest to the superior border of mandibular canal (paired t-tests) showed statistically significant difference in the mean difference of vertical bone height at each region between PAN and CBCT (p<0.001). Conclusion: PAN radiograph provides sufficient information for presurgical implant assessment at the posterior mandible in routine cases or during the unavailability of CBCT at the clinic. However, CBCT remains the best imaging modality for presurgical implant assessment as it has a minimal magnification error.

Assessment of a New Regression Equation for Mixed Dentition Space Analysis in Paediatric Population of Wardha, Maharashtra, India- A Research Protocol

Introduction: Prediction of the mesiodistal crown width of unerupted canines and premolars in mixed dentition analysis is crucial. When Tanaka-Johnston’s equations, the most popular approach, are applied to diverse ethnic groups, their accuracy is questioned. Aim: To derive a new regression equation of mixed dentition space analysis for predicting the size of unerupted canines and premolars teeth among paediatric population of Wardha, Maharashtra, India. Materials and Methods: The study will be conducted in two phases. The study design for First phase is observational and second phase is interventional. Dental study casts of 400 patients aged 11-18 years will be selected in the first phase. A Digital Vernier Caliper (DVC) will be used to measure the mesiodistal crown dimension of all erupted permanent teeth up to first molar. Between four mandibular incisors and the caninepremolar segments of both arches, correlation and linear regression equations will be created. In the second phase, 30 children aged 6-11 years will be randomly selected. Analysis of Tanaka-Johnston’s equations, Huckaba GW equation and the proposed equation will be compared and further statistical analysis will be carried out. Results: New derived regression equation will allow the closer prediction of the size of unerupted canines and premolars in the paediatric population of Wardha. Conclusion: This new equation will allow an accurate prediction of the width of unerupted canines and premolars at an earlier age in the said population.

Predicting the Mesiodistal Crown Dimensions of the Permanent First Molars from the Deciduous Second Molars.

Background This study aims to formulate regression equations that predict the mesiodistal crown widths of the permanent first molars utilizing the mesiodistal crown widths of the deciduous second molars. Methods Fifty pairs of study models belonging to 50 Iraqi children aged eight to nine years with sound mixed dentition were used to measure the mesiodistal crown widths of the permanent first molars and deciduous second molars using a pointed digital sliding caliper with 0.01 mm sensitivity. Side and gender differences were assessed, and the correlations between these teeth were obtained to develop the regression equations. Results The results revealed no significant side differences, so the samples were merged and analyzed for gender differences, which were found to be significant in all examined teeth except the mandibular permanent first molar. Direct, moderate, and highly significant correlations between the mesiodistal crown widths of the permanent first molars and deciduous second molars were found, which led to the development of regression equations. After applying these equations, the resultant predicted widths were compared to the actual widths, and the results revealed nonsignificant method differences. Conclusions A new method was developed to predict the widths of permanent first molars from the adjacent primary second molars with high precision.

Comparison between the mesiodistal crown dimensions of second primary molar with stainless steel crowns from different companies

Background: Due to the variations in tooth anatomy and size among different populations, this study aimed to compare the mesiodistal width of primary second molars in Iraqi children with the mesiodistal width of stainless-steel crowns from different companies. Materials and Methods: This cross-sectional study was conducted on 220 intact maxillary and mandibular primary second molars selected from boys and girls’ Iraqi children aged 8-9 years collected from different primary schools in Baghdad city. The mesiodistal dimensions of the selected teeth and the available maxillary and mandibular stainless-steel crowns from three different companies were measured by using a 3-D scanner, and then the whole measurements were calculated using 3 shape Ortho-analyzer software program. Results: Data were analyzed statistically via SPSS V 26 software and the results showed that there’s non-significant difference between the MD measurements of second primary molars between right and left sides, and high significant difference were recorded with higher mean values for boys than girls. When comparing the same mesiodistal measurement between molars with that of stainless-steel crowns, only limited sizes of stainless steel crowns were found to be fitted to the molars of Iraqi children. Conclusion: more studies need to be applied using other stainless steel crown companies to find the relation in the mesiodistal measurement of Iraqi populations.
 

Accuracy of Mesiodistal Crown Measurements using CBCT Images: A Comparison with Plaster Models

Aim: Comparison of the mesiodistal crown measurements made on plaster models and CBCT-images.Materials & Methods: Thirty pre-existing CBCT records of the maxillary arch and type-III stoneorthodontic models, soaped and polished were used in this study. A digital vernier caliper was used to makemeasurements on each cast. The largest mesiodistal crown dimension of each tooth was measured fromcentral incisor to the second premolar of one quadrant of the maxillary arch. The OnDemand 3D program(Cybermed Co, Seoul, Korea) was used to convert CT DICOM images into 3D reconstructed images. Themesiodistal crown width measured using the OnDemand 3D program.Results: The precision of the measurements on the plaster models and on the CBCT 3D reconstructedimages were the same. There was no significant difference between them as evaluated by paired t test.Conclusion: The distance and the precision of the measurements on the plaster models and on the CBCT3D reconstructed images are equivalent. CBCT 3D reconstructed images can replace the process of makingplaster models.

Mesio-distal crown width in permanent dentition amongst adolescent population of Province II of Nepal

Background: The purpose of this study was to gather normative data on the mesio-distal crown dimensions amongst adolescent population of Province II, Nepal, to make an accurate diagnosis and treatment planning in orthodontics. It will also be useful in various clinical disciplines of dentistry including basic dental and anthropological research.
 Materials and Methods: Samples were selected Full form OPD of M B Kedia Dental College, Birgunj, Nepal. Total numbers of participants were 120, out of which 60 males and 60 females were selected after initial examination aged between 11 to 23 years. Subjects with all permanent teeth erupted (except second and third molar) without any history of previous orthodontic treatment and with no dental anomalies were included in this study. The alginate impressions were made by the well trained dental surgeon. Digital vernier calliper providing measurements to ± 0.01millimeter(mm) was used to measure the mesio-distal dimension of all teeth.
 Results: The mean, range and standard deviation were calculated for the size of the teeth. Independent t-test was used to compare between male and female population. The significance level was set at p value <= 0.05. The population of Province II, Nepal shows greater sexual dimorphism in mesio-distal crown dimension which was exhibited by the maxillary molars (0.88 mm) followed by mandibular molars (0.38 mm). Similarly in anterior tooth segment the maxillary canines (0.29 mm) followed by the mandibular canines (0.27 mm).
 Conclusion: The mean mesio-distal crown dimensions of the permanent dentition of males were larger than that of females for each type of tooth except maxillary central and lateral incisor.

Mesiodistal Crown Dimensions of the Permanent Dentition in a Nigerian Population

Mesiodistal crown dimensions of the permanent dentition were assessed in a Nigerian population. The study sample consisted of 54 dental casts of Nigerian subjects (33 males; 21 females) with a mean age of 26.6 (sd = 2.1) years. The subjects had their permanent teeth present and fully erupted from first molar to first molar, no interproximal caries or restorations and no abnormal tooth sizes or shapes. Descriptive statistics are provided. Sex differences in the means and comparisons with the means from other population were evaluated using t-tests. Results revealed no statistically significant difference in mesiodistal crown dimensions between the sexes and no left to right side tooth size discrepancy in the sample. The study provides normative data on the mesiodistal crown dimensions of Nigerian subjects. Compared to African Americans, crown dimensions tended to be smaller in these Nigerians, especially in males.

Heritability and genetic integration of tooth size in the South Carolina Gullah.

This article provides estimates of narrow-sense heritability and genetic pleiotropy for mesiodistal tooth dimensions for a sample of 20th century African American individuals. Results inform biological distance analysis and offer insights into patterns of integration in the human dentition. Maximum mesiodistal crown dimensions were measured using Hillson-FitzGerald calipers on 469 stone dental casts from the Menegaz-Bock Collection. Narrow-sense heritability estimates and genetic and phenotypic correlations were estimated using SOLAR 8.1.1 with covariate screening for age, sex, age*sex interaction, and birth year. Heritability estimates were moderate (∼0.10 - 0.90; h2 mean = 0.51) for most measured variables with sex as the only significant covariate. Patterns of genetic correlation indicate strong integration across tooth classes, except molars. Comparison of these results to previously published work suggests lower overall heritability relative to other human populations and much stronger genetic integration across tooth classes than obtained from nonhuman primate genetic pleiotropy estimates. These results suggest that the high heritabilities previously published may reflect overestimates inherent in previous study designs; as such the standard estimate of 0.55 used in biodistance analyses may not be appropriate. For the Gullah, isolation and endogamy coupled with elevated levels of physiological and economic stress may suppress narrow-sense heritability estimates. Pleiotropy analyses suggest a more highly integrated dentition in humans than in other mammals.

Crown morphology of the mandibular first molars with distolingual roots

Background/purposeMost mandibular first molars have two roots. A major common variation of this tooth is the presence of a distolingual root, which is a common Mongoloid trait in certain populations. The aim of this article was to examine crown morphology in relation to the presence of the distolingual root. Materials and methodsUsing dental casts, the crown morphology of 141 mandibular first molars from 71 Taiwanese individuals was analyzed. Periapical radiographs were used to detect distolingual roots. The length and width of the crowns and the crown units (i.e., trigonid and talonid) were measured. Ten intercuspal distances and five cusp angles were examined. ResultsThe buccolingual dimension of the crown and its ratio to the mesiodistal dimension were significantly increased in molars with a distolingual root, compared to molars without a distolingual root. Mesiodistal crown dimensions were similar; however, the crown unit dimensions were different: molars with a distolingual root had a shorter mesiodistal trigonid dimension but a longer talonid dimension, compared to molars without a distolingual root. The intercuspal distances from the three buccal cusps to the distolingual cusp were significantly longer, however, the distance between the mesiobuccal cusp and mesiolingual cusp was significantly shorter in teeth with a distolingual root than in teeth without a distolingual root. A significantly wider mesiolingual angle and narrower distolingual angle were observed in molars with a distolingual root, compared to molars without a distolingual root. ConclusionThe presence of a distolingual root significantly increased the buccolingual dimension of the crown and the location of distolingual cusp is significantly closer to the lingual side.

Evaluation of validity of Tanaka-Johnston analysis in Mumbai school children.

Introduction:Estimation of the mesiodistal dimensions of the unerupted canines and premolars in the early mixed dentition is a necessary diagnostic aid in space management. Tanaka-Johnston analysis was developed for North American children. Anthropological study reveals that tooth size varies among different ethnicities. The present study was performed to evaluate the validity of Tanaka-Johnston method of mixed dentition arch analysis in Mumbai school children.Aims:(1) To determine the correlation between the sum of the mesiodistal widths of the permanent mandibular incisors and combined mesiodistal widths of the permanent mandibular and maxillary canines and premolar in Mumbai school children. (2) To examine the applicability of Tanaka-Johnston method of prediction.Materials and Methods:Dental casts of maxillary and mandibular arches of 300 children, 147 boys and 153 girls within the age group of 12–15 years, with permanent dentitions were fabricated. The mesiodistal crown dimensions of teeth were measured with a dial caliper. Tanaka-Johnston method of mixed dentition arch analysis was performed for the study population, and statistical analysis was done.Statistical Analysis Used:Descriptive statistics including the mean, standard deviation, range, and standard error were calculated and tabulated.Results:Tanaka-Johnston's equation when applied to the data available for Mumbai school children, it was observed that it slightly overestimates the tooth size.Conclusions:(1) There was a positive correlation between the width of mandibular incisors and mandibular and maxillary canines and premolars. (2) The Tanaka-Johnston prediction method was not accurate for a sample of Mumbai school children.

Mesio-distal crown dimension of permanent dentition in normal, crowding, and spacing of young adult sample aged 18-25 years

This study aimed to assess the effect of tooth width in malocclusion in relation to normal, crowding, and spacing dentition. Materials and methods: The sample included dental casts of some dental students and orthodontic patients; their age was (18-25) years and having three groups normal, crowding, and spacing dentition groups. The sample was equally divided to three groups normal, crowding, and spacing dentition groups, each group contained 50 maxillary and 50 mandibular casts that were further subdivided by gender; all the stone casts were measured by highly sensitive digital vernier. Results and Conclusions: Non-significant side difference was found in both dental arches in the three studied groups. Males had higher mesiodistal crown dimension than females in all three groups, with significant gender difference in crowding and normal dentition groups. The mesiodistal distance of the segment measurements (Total Anterior material; Total Posterior material and Total teeth material) were larger in crowded dentition then followed by normal and spaced dentition groups respectively in both gender. Total Anterior material in both arches had direct significant correlation with crowding malocclusion, while maxillary Total Anterior material had indirect significant correlation with spacing malocclusion.

Comparison of the Mesiodistal Crown Dimensions of Upper And Lower Central Incisors Between the Natural Dentition and Artificial Teeth in Iran

Comparison of the Mesiodistal Crown Dimensions of Upper And Lower Central Incisors Between the Natural Dentition and Artificial Teeth in Iran

Regression Equations and Probability Tables for Mixed Dentition Analysis in a Nigerian Population

Objectives: The objectives of this study were to evaluate the applicability of both the Moyers and the Tanaka and Johnston mixed dentition space analysis in a Nigerian population, and develop a new probability tables and regression equations for prediction of the size of unerupted canines and premolars in Nigerian population. Methods: The mesiodistal crown dimensions of 54 dental casts of Nigerian subjects were measured with digital calipers. Gender differences were evaluated with independent t-test. Correlation coefficients between the combined mesiodistal widths of the permanent mandibular incisors and the canine and premolars of the maxillary and mandibular arches were determined respectively. Linear regression equations and probability tables were derived and used to compare actual Nigerian tooth widths with those predicted by the Moyer’s probability table and regression equations of Tanaka and Johnston. Results: The regression equations for the maxillary arch males: Y=0.49x+10.98, females: Y=0.47x+12.95, sexes combined: Y=0.47x+11.49, and the mandibular arch males: Y=0.54x+9.53, females: Y=0.39x+12.75, sexes combined: Y=0.51x+10.27 were derived. No statistically significant differences (p>0.05) were observed in the mesiodistal widths of maxillary canine and premolars for combined sexes at 75 th percentile, and in the mandibular arch for male at 85 th percentile confidence levels when compared with those of the Moyers’ probability tables, while there were statistically significant differences (p<0.05) at all the remaining percentile levels. Tanaka and Johnston’s equations underestimated canine and premolars mesiodistal widths in the mandibular and maxillary arches.

The Value of Maxillary Central Incisors and Canines in Gender Determination as an Aid in Forensic Dentistry

Background: This study aimed to determine the gender of a sample of Iraqi adults utilizing the mesio-distal width of maxillary central incisors and canines and to determine the percentage of dimorphism as an aid in forensic dentistry. Materials and methods: The sample included 230 subjects (115 males and 115 females) with an age ranged between 17- 25 years and Class I dental and skeletal relations. Study casts were taken for each subject and the mesio-distal crown dimension was measured manually from the contact points for the maxillary central incisors and canines (both sides) using digital vernier caliper gauge. Descriptive statistics were obtained for the measurements for both genders; independent samples t-test was performed to evaluate the gender difference, percentage of dimorphism and stepwise discriminant function statistics were performed to determine the teeth that can be used for gender identification in addition to the percentage of gender identification accuracy. Results and Conclusions: Generally, the mesio-distal dimensions of the maxillary central incisor and canine were larger in males than females with a high significant difference (P . 0.001). Stepwise discriminant function statistics indicated that the right central incisor and canine were the most predominant teeth in gender identification and the accuracy of identification reached up to 69.6%. Keywords: Mesio-distal tooth dimension, Forensic dentistry, gender determination.

Genders Identification Using Mandibular Canines : Iraqi Study

Background: This study aimed to determine the gender of a sample of Iraqi adults using the mesio-distal width of mandibular canines, inter-canine width and standard mandibular canine index, and to determine the percentage of dimorphism as an aid in forensic dentistry. Materials and methods: The sample included 200 sets of study models belong to 200 subjects (100 males and 100 females) with an age ranged between 17-23 years. The mesio-distal crown dimension was measured manually, from the contact points for the mandibular canines (both sides), in addition to the inter-canine width using digital vernier. Descriptive statistics were obtained for the measurements for both genders; paired sample t-test was used to evaluate the side difference of mandibular canines in both genders, independent samples t-test was performed to evaluate the gender difference in addition to the percentage of dimorphism and percentages of correctly classified and misclassified cases using the standard mandibular canine index. Results: The mesio-distal widths of the mandibular canines were non-significantly slightly larger in males than females, while the inter-canine width was larger in males than females with a high significant difference. The accuracy of genders determination using standard mandibular canine index was 32% for males, 59% for females and 45.5% for the combined sample. The percentages of dimorphism were 0.58% for the canine mesio-distal width, 3.99% for the inter-canine width and 3.85 for the mandibular canine index. Conclusions: The mandibular inter-canine width and mandibular canine index gave better percentage of dimorphism than the mesio-distal width of mandibular canines. On the other hand, standard mandibular canine index showed low accuracy for gender determination.

Comparison of Mesiodistal Crown Dimension and Arch Width in Subjects with and without Hypodontia

Tooth agenesis is one of the most common anomalies in the development of the human dentition and may have wider associations in the development of the dentition including tooth size. This study aimed to compare mesiodistal crown dimension and arch widths between subjects with hypodontia and subjects without hypodontia (control group). Dental casts were measured of 55 hypodontia patients and 55 patients with total permanent dentition (control group). Tooth agenesis was evaluated for hypodontia, excluding the third molars, from the panoramic radiograph. Mesiodistal crown dimensions were recorded by measuring all erupted teeth on study models with a digital Mitutoyo caliper (Mitutoyo U.K. Ltd, United Kingdom). Patients with hypodontia had smaller mesiodistal tooth dimensions than the control group, and this difference was statistically significant (p < 0.05) for all teeth in both genders. Upper lateral incisors, lower central incisors, and lower second molars showed the highest difference in tooth dimension. Also, the intercanine and intermolar arch widths in the hypodontia group were statistically significantly reduced (p < 0.05) compared with the control group. The findings indicate that the mesiodistal crown dimensions and arch widths are reduced in hypodontia patients. This should be taken into account when planning orthodontic treatment. Congenital absence of permanent teeth has direct clinical implications. Early detection of the number of missing teeth and evaluation of the tooth size and arch width is of immense value in the planning and managing treatment with a multidisciplinary team approach to achieve an aesthetic and functional dentition and reduce the complications of hypodontia.

Different manifestations of Class II Division 2 incisor retroclination: A morphologic study

The aims of this study were to investigate whether there is a different transverse morphologic pattern of dental arches among patients with different manifestations of Class II Division 2 incisor retroclination and to evaluate to what extent the pattern of smaller-than-average teeth in Class II Division 2 malocclusion is common to all groups studied. This information might clarify whether different Class II Division 2 phenotypes represent a single etiology or multiple etiologies. The sample comprised 108 subjects with Class II Division 2 malocclusions, divided into 2 groups according to the type of incisor retroclination: group I included 43 Class II Division 2 subjects with retroclination exclusively of the maxillary central incisors, and group II included 65 Class II Division 2 subjects with retroclination of the 4 maxillary incisors. Maxillary and mandibular intercanine and intermolar widths as well as mesiodistal crown dimensions of the 4 maxillary and mandibular incisors were determined from the patients' initial study models. Mean values of all variables were compared between the 2 groups by sex with analysis of variance. From the comparison between these 2 groups, no statistically significant differences were found for all transverse measurements (P>0.05). For all mesiodistal measurements analyzed, statistically significant differences between the groups were only found for the mean value of both maxillary lateral incisors' mesiodistal dimensions in both sexes (P<0.05). It is not possible to attribute a characteristic pattern of dental arch-width and incisor mesiodistal dimensions to the different manifestations of incisor retroclination in Class II Division 2 malocclusion.

Comparison of two non-radiographic techniques of mixed dentition space analysis and evaluation of their reliability for Bengali population.

Context:Mixed dentition arch analysis system is an important criterion in determining the type of orthodontic treatment plan. Different mixed dentition arch analysis system are available and among them both Moyer's and Tanaka-Jhonson method of space analysis was developed for North American children. Anthropological study reveals that tooth size varies among different ethnicities The present study was performed to determine the reliability of Moyer's and Tanaka-Jhonson's method of mixed dentition arch analysis system among Bengali population.Aims:To perform the comparative evaluation of the two mixed dentition space analysis system among Bengali population.Materials and Methods:Dental casts of maxillary and mandibular arches of 70 Bengali children with permanent dentitions were fabricated. The mesiodistal crown dimensions of all erupted permanent incisors, canines, and premolars were measured with digital callipers. For particular sum of mandibular incisors, Moyer's and Tanaka-Jhonson's mixed dentition arch analysis were calculated and further statistical analysis was carried on.Statistical analysis used:Descriptive statistics including the mean, standard deviation, and minimum and maximum values, unpaired‘t’ tests, correlation coefficient “r” were calculated and tabulated.Results:Tanaka and Johnston regression equations under-estimated the mesiodistal widths of permanent canines and premolars. On the other hand, there were no statistically significant differences between actual mesiodistal widths of canines and premolars and the predicted widths from Moyers charts at the 50% level for the lower and upper arches, among Bengali population.Conclusions:The study suggested that both Moyer's and Tanaka-Jhonson's mixed dentition arch analysis are applicable in Bengali population but with little modification in their regression equation.

Dental Arch and Mesiodistal Crown Dimensions in Normal, Crowded, and Spaced Samples

Dental Arch and Mesiodistal Crown Dimensions in Normal, Crowded, and Spaced Samples