Precisión del método de Moyers para predecir tamaño de dientes no erupcionados. Municipio Centro Habana. 2020 / Accuracy of the Moyers method to predict size of non-erupted teeth. Centro Habana Municipality. 2020

Introducción: El método de Moyers se utiliza en Cuba para predecir el tamaño de caninos y bicúspides no erupcionados. Objetivo: Determinar la precisión del método de Moyers para predecir tamaño de dientes no erupcionados en pacientes de Centro Habana. Material y métodos: Investigación de desarrollo en el Policlínico Luis Galván Soca de marzo 2019 a mayo de 2020. Universo formado por individuos de 12 a 24 años. Muestra de 100 personas seleccionadas por muestreo aleatorio simple. Se analizó la tabla de Moyers por sexos para todos los percentiles. Resultados: En el sexo femenino para la arcada superior e inferior el error cuadrático medio menor correspondió al percentil 50: 0,476 y 0,464 respectivamente; único donde las diferencias entre el valor estimado y el real no fueron significativas. Por tanto, el percentil elegible para féminas en ambas arcadas sería el 50 por ciento. En masculinos para la arcada superior el error cuadrático medio menor (0,576) para el percentil 65 con diferencias entre el valor estimado y el real no significativas(p=0,269); mientras en la arcada inferior fue de 0,592 para el percentil 75. Por tanto, el percentil elegible para hombres en la arcada superior fue el 65 y en la inferior el 75; la fuerza de esta correspondencia es intensa para ambas arcadas. Conclusiones: En la población que se estudia el método de Moyers, para predecir el tamaño de dientes no erupcionados es preciso en el sexo femenino, pero no en el masculino(AU)

Introduction: In Cuba, the Moyers method is used to predict the size of non-erupted canines and bicuspids. Objective: To determine the precision of the Moyers method to predict the size of non-erupted teeth in patients from Centro Habana municipality. Material and Methods: A development research was conducted in Luis Galván Soca Polyclinic from March 2019 to May 2020. The universe consisted of individuals aged 12-24 years. The sample was composed of 100 people who were selected by simple random sampling. Moyers table was analyzed by sex for all percentiles. Results: In the female sex, the lower mean square error for the upper and lower arches corresponded to the 50th percentile: 0.476 and 0.464 respectively, the only one in which the difference between the estimated and the real values was not significant. Therefore, for females, the eligible percentile in both arches would be 50 percent. In males, in the upper arches, the lower mean square error (0.576) for the 65th percentile showed no significant differences between the estimated and the real values (p = 0,269); however, in the lower arch it was 0,592 for the 75th percentile. Therefore, in the upper arch, the eligible percentile for males was 65 while, in the lower arch, it was 75; the strength of this correspondence is intense for both arches. Conclusions: In the population studied, the Moyers method was found to be accurate in predicting the size of non-erupted teeth in females, but not in males(AU)

Diskrepansi Saiz Gigi Intermaksila dan Kesannya terhadap Hasil Rawatan Ortodontik (Intermaxillary Tooth Size Discrepancies and Its Effect on Orthodontic Treatment Outcome) / Jurnal Sains Kesihatan Malaysia

@#Intermaxillary tooth size discrepancy (TSD) is the disproportion in patients’ tooth size that is usually referred to the Bolton analysis. This size imbalance may also affect the outcome of orthodontic treatment. Therefore, this retrospective study was conducted to determine the prevalence of intermaxillary tooth size discrepancy (TSD) beyond 2 standard deviation (2 SD) from Bolton’s mean in orthodontic patients and to evaluate the effect of TSD beyond 2 SD of Bolton’s mean on orthodontic treatment outcomes. A total of 226 sets of orthodontic study models that met the selection criteria were selected from 3077 orthodontic cases. Bolton's analysis of the anterior and overall ratios was performed on each of the pre-treatment models. The orthodontic treatment outcomes for the cases which were identified of having TSD beyond 2 SD were evaluated and any interventional techniques to improve the outcome of the treatment were recorded. The results showed that 29.20% of cases had TSD beyond 2 SD of Bolton’s mean. 26.54% of cases had anterior ratio of more than 2 SD. Meanwhile, 7.08% of cases had an overall ratio greater than 2 SD. Of all cases with TSD beyond 2 SP, most of these cases (62.12%) had affected the outcome of orthodontic treatment. In conclusion, there is more than one quarter of orthodontic patients present with TSD beyond 2 SD of Bolton’s mean which may influence the outcome of orthodontic treatment. Intervention techniques should be carefully planned to achieve satisfactory treatment outcomes.

Bolton tooth size analysis in a sample of Sudanese adults / Análise de Bolton do tamanho dentário em uma amostra de adultos sudaneses

Introduction: A correct proportion between the upper and lower teeth is critical to achieving proper occlusal interdigitation, ideal overjet, and good molar intercuspation at the end of orthodontic treatment. Objectives: To determine the anterior and overall Bolton's ratio in the Sudanese population, investigate gender differences in tooth size ratios, and to compare these results with Bolton's original ratio norm. Material and Methods: The sample consisted of dental casts of 104 Sudanese University students with normal occlusion (52 females, 52 males), aged between 16-26 years randomly selected from AL- Neelain University. An electronic digital caliper was used to measure the mesiodistal tooth size of the maxillary and mandibular teeth anterior to the second molars. These measurements were then used to obtain Bolton's ratio. Mean, range, and standard deviation of the anterior and overall ratios were computed for each subject. T-Tests were used to compare gender differences and to investigate differences between the results of this study and Bolton's original ratio. Results: Anterior and overall Bolton ratios for males were 78.43 ± 2.44 and 93.901 ± 9.8 and for females were 78.29 ± 2.6 and 91.67 ± 3.3 percent, respectively. There were no statistically significant differences between males and females for the anterior and overall ratios (P>0.05). The anterior and overall Bolton's ratios among Sudanese University students were 78.37 ± 2.54, and 92.79 ± 7.43 percent, respectively. A statistically significant difference between this study and Bolton's study was found in both anterior and overall ratio (P≤ 0.05). Conclusion: Bolton's mean ratios may not be applicable to the Sudanese population. (AU)

Introdução: Uma proporção correta entre os dentes superiores e inferiores é crítica para alcançar a interdigitação oclusal adequada, overjet ideal e boa intercuspidação molar ao final do tratamento ortodôntico. Objetivos: determinar a proporção anterior e geral de Bolton na população sudanesa, investigar as diferenças de gênero nas proporções de tamanho dos dentes e comparar esses resultados com a norma original de Bolton. Material e Métodos: A amostra foi constituída por modelos de gesso de 104 universitários sudaneses com oclusão normal (52 mulheres, 52 homens), com idades entre 16-26 anos, selecionados aleatoriamente na Universidade AL-Neelain. Um paquímetro digital eletrônico foi usado para medir o tamanho mesiodistal dos dentes superiores e inferiores anteriores aos segundos molares. Essas medidas foram então usadas para obter o índice de Bolton. Média, intervalo e desvio padrão das relações anterior e geral foram calculados para cada amostra. Os testes t foram usados para comparar as diferenças de gênero e para investigar as diferenças entre os resultados deste estudo e a proporção original de Bolton. Resultados: Os índices de Bolton anterior e geral para homens foram 78,43 ± 2,44 e 93,901 ± 9,8 e para mulheres foram 78,29 ± 2,6 e 91,67 ± 3,3 por cento, respectivamente. Não houve diferenças estatisticamente significativas entre homens e mulheres para os índices anterior e geral (P> 0,05). Os índices de Bolton anterior e geral entre os estudantes da Universidade sudanesa foram 78,37 ± 2,54 e 92,79 ± 7,43 por cento, respectivamente. Uma diferença estatisticamente significativa entre este estudo e o estudo de Bolton foi encontrada na proporção anterior e geral (P≤ 0,05). Conclusão: os índices médios de Bolton podem não ser aplicáveis à população sudanesa (AU)

Nuevo método para predecir el diámetro mesiodistal de las coronas de caninos y premolares no erupcionados. Estudio Piloto / New Method to Predict Mesiodistal Diameter in Unerupted Canine and Premolars Crown. Pilot Study

RESUMEN: La determinación de la discrepancia de la longitud del arco y del tamaño del diente en la dentición mixta, requiere una predicción precisa del ancho mesiodistal de los dientes permanentes no erupcionados, para prevenir futuras maloclusiones. Objetivo: fue generar una nueva ecuación regresiva para predecir el diámetro mesiodistal de premolares y caninos, usando como predictor incisivos inferiores y molares superiores. Material y método: El estudio se realizó en el Centro Clínico de la Araucanía. La muestra está compuesta por modelos dentales históricos de 200 escolares (93 niños y 107 niñas) de toda la IX región, Chile. Edad de 13-16 años. Las mediciones del ancho mesiodistal de incisivos mandibulares, caninos y premolares maxilares y mandibulares, se realizaron con la ayuda del calibrador Vernier calibrado a 0,01 de un milímetro. Resultados: Estos muestran que hay una correlación moderada entre el molar superior y premolares superiores e inferiores. Además, los incisivos inferiores se correlacionan en mayor medida con los caninos superiores e inferiores. No hay diferencias significativas entre hombres y mujeres. Conclusión: Se desarrolló una nueva fórmula con un 75% de precisión para predecir el ancho de dientes caninos y premolares en dentición mixta en la población chilena de la región de la Araucanía, siendo mejor que la actual fórmula de Tanaka.

ABSTRACT: Precautionary measures are necessary to prevent a potential irregularity from progressing into a more severe malocclusion. The determination of the tooth size-arch length discrepancy in mixed dentition requires an accurate prediction of the mesiodistal widths of the unerupted permanent teeth to prevent future malocclusions. Objective: The purpose of this study is to generate a new regressive equation to predict the diameter of the cuspid and bicuspid by measuring the wide of lower incisor and upper molar teeth in a Chilean population sample. Matherials and methods: the study was conducted in the Araucanía Clinical Center in Temuco city and the sample was composed of historical dental cast from 200 school children (93 boys and 107 girls), of IX region, Chile. Age group of 13-16 years old. Measurements of the mesiodistal widths of mandibular incisors, maxillary and mandibular canines and premolars were made with the help of Vernier gauge calipers calibrated to 0.01 of 1 millimeter. Results: The results show that there is a moderate correlation between the upper molar and upper and lower premolars. In addition, the lower incisors are correlated to a greater extent with the upper and lower canines. There are no significant differences between men and women. Conclusion: A new formula with 75% accuracy was developed to predict the width of canine teeth and premolars in mixed dentition in the Chilean population of the Araucanía region. This formula is better than the current Tanaka method.

Incisor size analysis to predict mesiodistal diameter in unerupted canine and premolar crowns in native and non-native Chilean population / Análisis del tamaño de incisivos para predecir el diámetro mesiodistal de coronas de caninos y premolares no erupcionados en población chilena nativa y no nativa

SUMMARY: The principal orthodontic problems observed in the mixed dentition phase are related to arch length and tooth size discrepancy. In order to identify such space discrepancies different methods of mixed dentition space analyses have been introduced. For this reason the purpose of this study is to generate a new regressive equation to predict the diameter of cuspid and bicuspid teeth through mesiodistal widths of lower incisors in a Chilean population sample between native and non-native population. The study was conducted at the Araucania Dental Clinic in Temuco, and the sample comprised of historical dental casts from 200 school children (93 boys and 107 girls) from Temuco, Chile, between 13-16 years of age. The native Mapuche population consisted of 107 students and the non-native of 93 students. Measurements of the mesiodistal widths of mandibular incisors, maxillary and mandibular canines and premolars were carried out with the help of Vernier gauge calipers calibrated to 0.01 of a millimeter. The results show that there are differences in the mesiodistal diameter size of incisors, and canines and premolars in the two studied groups. There is a low correlation of the variables studied. In conclusion, significant sexual dimorphism in tooth sizes exists in the native sample, and there is no difference in non-native population. It is necessary to develop a predictive formula that is greater than 70 % of accuracy for clinical application. Resonance imaging (MRI).

RESUMEN: El principal problema ortodóncico observado en la etapa de dentición mixta está relacionado con la longitud del arco y la discrepancia del tamaño de los dientes. En orden a identificar tal discrepancia de espacio, diferentes métodos de análisis de espacio en dentición mixta han sido introducidos. Por esta razón el objetivo de este estudio fue generar una nueva ecuación regresiva para predecir el diámetro mesiodistal de caninos y premolares a partir del ancho de los incisivos centrales inferiores en una muestra de población chilena nativa y no nativa. El estudio fue realizado en la Clínica de Ortodoncia Araucanía en Temuco. La muestra fue seleccionada de una colección histórica de modelos dentales, 200 escolares (93 niños y 107 niñas) de la ciudad de Temuco, Chile con edades entre 13 y16 años. La población nativa fueron 107 estudiantes Mapuches y los no nativos fueron 93 estudiantes. Las mediciones del ancho mesiodistal de los incisivos mandibulares, caninos maxilares and mandibulares y premolares fueron realizadas con la ayuda de un medidor Vernier calibrado a 0.01 de milímetro. Los resultados muestran que hay diferencias en el diámetro mesiodistal de incisivos, y caninos y premolares en los grupos estudiados. Hay una baja correlación de las variables estudiadas. En conclusión, hay diferencias significativas en el tamaño de dientes entre hombres y mujeres en la muestra de nativos, y no hay diferencias en la población no nativa. Es necesario desarrollar una fórmula predictiva que sea mayor a 70 % de seguridad para aplicaciones clínicas.

Analysis of crown size and morphology, and gingival shape in the maxillary anterior dentition in Korean young adults

PURPOSE: The aim of this investigation was to analyze the dimensions of clinical crowns and to classify the crown and the gingival type in the anterior teeth in Korean young adults. MATERIALS AND METHODS: Casts were obtained from 50 subjects ranging in age from 24 to 32. Measurements of length and width were made on the casts using a pair of digital calipers on the entire dentition. Crown thickness and papilla height were also measured and MDW/CL (mesiodistal width to clinical length) and CW/CL (cervical width to clinical length) ratios of the maxillary anterior teeth were calculated. The K-clustering method was used for CW/CL to classify the anterior tooth shape into three groups (tapered, ovoid, and square), and one-way analysis of variance and Duncan's post-hoc comparison were used to evaluate statistical significance between the groups. Pearson's correlation analysis was performed between tooth shape and papillary height (PH) to demonstrate the correlation between tooth shape and gingival morphological characteristics. RESULTS: The average length of the maxillary central incisors was 9.89 mm; the mesio-distal width was 8.54 mm; and the ratio of width/length was 0.86 in Korean young adults. The average bucco-palatal thickness of the central incisor was 3.14 mm at the incisal 1/3 aspect. Ovoid type was the most common tooth shape (48%), followed by square type (29%) and taper type (23%) in the central incisors of Korean young adults. Tooth shape and gingival type were correlated with each other. CONCLUSION: New reference data were established for tooth size in Korean young adults and the data show several patterns of tooth shape and gingival type. Clinicians should diagnose and treat based on these characteristics for better results in the Korean population.

Measurments of Bolton’s Tooth Width Ratios in Karnataka Population: A Preliminary Study.

Aim: This study was conducted to establish the Bolton’s ratios’ norms ((The mean Overall Ratio (OR) and Anterior Ratio (AR) norms)) in 100 Karnataka subjects and to compare it with the overall ratio and anterior ratio of the Bolton’s analysis which would be an aid in diagnosis and treatment planning of orthodontic cases. It will also help in determining functional and esthetic outcome of the case. Methodology: Epidemiological survey was carried out for 100 subjects (50 males and 50 females), 14-25 years of age. The study groups were from Karnataka state in India. Every individual was assessed for occlusal traits and good quality impressions were taken for 100 selective individuals. Mesiodistal tooth dimensions were measured from right first permanent molar to left first permanent molar in maxillary and mandibular arches. Measurements were taken using digital vernier caliper. Anterior and overall ratio were calculated for each model. Data was statistically analysed by using statistical package for social sciences (SPSS) software. Results: The results showed that the overall ratio was 92.23 for males and 91.78 for females. The anterior ratio was 77.87 for males and 77.69 for females. The study indicated that there was statistically significant difference between the overall ratio and anterior ratio of Karnataka subjects and Caucasian subjects. Conclusion: The study concluded that inter arch tooth size a relationship varies and are specific.

Rehabilitation of a patient with non-syndromic partial oligodontia

Oligodontia is defined as a congenital tooth agenesis with the absence of six or more permanent teeth. This clinical report describes a patient with non-syndromic partial oligodontia, with retained deciduous teeth and the absence of 16 permanent teeth. Anterior esthetic problems were caused by interarch tooth size discrepancy, interdental space, aberrant tooth dimensions, and the absence of centric contacts of the anterior teeth. Prosthetic restoration after orthodontic and implant treatment was performed with a multi-disciplinary team approach. Favorable functional and esthetic results were obtained using a definitive prosthesis.

New prediction equations for the estimation of maxillary mandibular canine and premolar widths from mandibular incisors and mandibular first permanent molar widths: A digital model study / 대한치과교정학회지

OBJECTIVE: The primary aim of the study was to generate new prediction equations for the estimation of maxillary and mandibular canine and premolar widths based on mandibular incisors and first permanent molar widths. METHODS: A total of 2,340 calculations (768 based on the sum of mandibular incisor and first permanent molar widths, and 1,572 based on the maxillary and mandibular canine and premolar widths) were performed, and a digital stereomicroscope was used to derive the the digital models and measurements. Mesiodistal widths of maxillary and mandibular teeth were measured via scanned digital models. RESULTS: There was a strong positive correlation between the estimation of maxillary (r = 0.85994, r2 = 0.7395) and mandibular (r = 0.8708, r2 = 0.7582) canine and premolar widths. The intraclass correlation coefficients were statistically significant, and the coefficients were in the strong correlation range, with an average of 0.9. Linear regression analysis was used to establish prediction equations. Prediction equations were developed to estimate maxillary arches based on Y = 15.746 + 0.602 × sum of mandibular incisors and mandibular first permanent molar widths (sum of mandibular incisors [SMI] + molars), Y = 18.224 + 0.540 × (SMI + molars), and Y = 16.186 + 0.586 × (SMI + molars) for both genders, and to estimate mandibular arches the parameters used were Y = 16.391 + 0.564 × (SMI + molars), Y = 14.444 + 0.609 × (SMI + molars), and Y = 19.915 + 0.481 × (SMI + molars). CONCLUSIONS: These formulas will be helpful for orthodontic diagnosis and clinical treatment planning during the mixed dentition stage.

A Preliminary Study of Malay and Chinese Bite Mark in UKM Using Dental Wax / Jurnal Sains Kesihatan Malaysia

Identifi cation of unknown suspect through bite marks has always been challenging. Narrowing list of suspects through sex and race markers is always recommend but rarely utilized due to limited publication in this area. Thus, this preliminary research was aimed to study the difference of bite mark made on dental wax between sex and race. A sample size of 40 UKM undergraduates comprising of Malay (male = 10, female = 10) and Chinese (male = 10, female = 10) were used in this study. Bite mark of subject was obtained through dental wax, digitally scanned and analyzed using Image-J software. Parameters measured were anterior teeth size, intercanine width and anterior teeth relative rotation. Result indicated that mandible left canine tooth size had signifi cant sexual dimorphism (p < 0.05) in differentiating sex. The means for male and female measured were 4.63 ± 1.05 mm and 5.35 ± 0.87 mm respectively. In addition to the result, tooth size of maxillary left canine and mandible left lateral incisor were signifi cantly different (p < 0.05) between races. Means for mandible left canine Malay and Chinese were 5.27 ± 1.01 mm and 4.50 ± 1.22 mm respectively. Furthermore, left lateral incisor mandible had means of 5.15 ± 0.87 mm and 4.60 ± 0.74 mm for Malay and Chinese respectively. Unfortunately, there were no signifi cant differences for intercanine width and anterior teeth relative rotation between the two major races in Malaysia. In conclusion, this research has demonstrated the possibility of using tooth size of mandible left canine, maxillary left canine and mandible left lateral discriminate sex and race.

Dentoskeletal features in individuals with ectopic eruption of the permanent maxillary first molar / 대한치과교정학회지

OBJECTIVE: The aim of the study was to analyze the prevalence and distribution of ectopic eruption of the permanent maxillary first molar (EEM) in individuals scheduled for orthodontic treatment and to investigate the association of EEM with dental characteristics, maxillary skeletal features, crowding, and other dental anomalies. METHODS: A total of 1,317 individuals were included and randomly divided into two groups. The first 265 subjects were included as controls, while the remaining 1,052 subjects included the sample from which the final experimental EEM group was derived. The mesiodistal (M-D) crown width of the deciduous maxillary second molar and permanent maxillary first molar, maxillary arch length (A-PML), maxillomandibular transverse skeletal relationships (anterior and posterior transverse interarch discrepancies, ATID and PTID), maxillary and mandibular tooth crowding, and the presence of dental anomalies were recorded for each subject, and the statistical significance of differences in these parameters between the EEM and control groups was determined using independent sample t-tests. Chi-square tests were used to compare the prevalence of other dental anomalies between the two groups. RESULTS: The prevalence of maxillary EEM was 2.5%. The M-D crown widths, ATID and PTID, and tooth crowding were significantly greater, while A-PML was significantly smaller, in the EEM group than in the control group. Only two subjects showed an association between EEM and maxillary lateral incisor anomalies, which included agenesis in one and microdontia in the other. CONCLUSIONS: EEM may be a risk factor for maxillary arch constriction and severe tooth crowding.

The role of polymorphisms associated with early tooth eruption in dental and occlusal traits in East Asian populations / 대한치과교정학회지

OBJECTIVE: A recent study suggested that rs6504340, a polymorphism within the homeobox B (HOXB) gene cluster, is associated with the susceptibility for malocclusions in Europeans. The resulting malocclusions require orthodontic treatment. The aim of this study was to investigate the association of rs6504340 and other dentition-implicated polymorphisms with dental and occlusal traits in Korean and Japanese populations. METHODS: The study participants included 223 unrelated Koreans from the Busan area and 256 unrelated Japanese individuals from the Tokyo metropolitan area. DNA samples were extracted from saliva specimens. Genotyping for rs6504340 and four single nucleotide polymorphisms (SNPs) that have been shown to be associated with the timing of first tooth eruption and the number of teeth at 1 year of age (rs10506525, rs1956529, rs9674544, and rs8079702) was performed using TaqMan assays. The Index of Orthodontic Treatment Need (IOTN), overjet, overbite, arch length discrepancy, crown sizes, and length and width of the dental arches were measured. Spearman's correlation coefficients were calculated to evaluate relationships between rs6504340 and these dental/occlusal traits. RESULTS: We evaluated the aesthetic components and dental health components of the IOTN in the Korean and Japanese populations and found that neither rs6504340 nor the other four SNPs showed any association with dental and occlusal traits in these East Asian populations. CONCLUSIONS: These negative results suggest that further research is needed to identify the genetic determinants of malocclusions in order to reach a consensus.

Tooth size and metabolic requirements in primates: the 'equivalence between exponents' under discussion / Tamaño de la dentición y requerimientos metabólicos en primates: la 'equivalencia entre exponentes' bajo discusión

The functional significance of teeth size, specifically postcanine tooth size has contributed a vast amount of scientific literature. Nevertheless, these studies have been based on 'equivalence between exponents'. That is, when the tooth size scales to the 0.75 power of body size exponent is interpreted as reflecting differences in metabolic requirements. On the contrary, if the obtained exponent is close to isometry, such slope is interpreted as that variation in teeth size is an incidental consequence of body size variation. In this paper, we show the results of a study in which the relationship between postcanine tooth occlusal area (PCOA) and basal metabolic rate (BMR) has been evaluated in 28 primate species. On one hand, the results obtained indicate that there is a high correlation between the BMR and the size of the PCOA, even when phylogenetic control tests are used, and that isometry cannot be discarded in both cases. However, if the effects of body mass are removed, a null slope cannot be discarded. On the other hand, when body mass (BM) is taken as the independent variable and PCOA as the dependent one, the slope obtained evidences a negative allometry, and this holds also when phylogenetic control is used. Given these contradictory results, we suggest that the rule of 'equivalence between exponents' is not a good approach for obtaining inferences on the function of postcanine teeth...

El significado funcional del tamaño de los dientes, y más concretamente del tamaño de la dentición poscanina, ha contribuido al desarrollo de una vasta literatura científica. No obstante, casi todos estos trabajos se han centrado en la 'equivalencia entre exponentes'. Así, cuando el tamaño de los dientes escala siguiendo una pendiente de 0,75 respecto al tamaño corporal se interpreta que las diferencias en tamaño reflejan los cambios en los requerimientos metabólicos. Si, por el contrario, el exponente obtenido es cercano a la isometría, la inferencia que se establece es que el cambio en el tamaño de la dentición es una consecuencia incidental del cambio en el tamaño corporal. En este artículo mostramos los resultados de un estudio en el que se han evaluado las relaciones entre el área de la dentición poscanina (PCOA) y la tasa metabólica basal (BMR) en 28 especies de primates. Los resultados obtenidos indican, en primer lugar, que existe una fuerte correlación entre BMR y PCOA, incluso cuando el efecto de la filogenia es controlado. Sin embargo, cuando se evita el efecto del tamaño no se puede descartar que la pendiente sea igual a cero. En segundo lugar, cuando se realiza una regresión usando el tamaño corporal (BM) como variable independiente y PCOA como dependiente, la pendiente obtenida es alométricamente negativa, lo que se mantiene cuando se controla para la filogenia. Dado que los resultados son contradictorios, sugerimos que la regla de la 'equivalencia entre exponentes' no es una buena aproximación para obtener inferencias sobre la función de la dentición poscanina...

Comparison of Anterior Tooth Size Discrepancies Among Different Malocclusion Groups

Background: Discrepancies between tooth sizes can cause orthodontic problems such as crowding and improper occlusion. By identifying these problems, better orthodontic treatment outcome can be achieved. The aim of this study is to identify anterior tooth size discrepancies among 4 different types of malocclusion i.e. Class I; Class II division 1 (II/1); Class II division 2 (II/2); and Class III. Methods: A retrospective study was carried out using 200 orthodontic study models where 50 study models were taken for each of the 4 malocclusion groups. The samples were selected using random sampling technique based on the orthodontic waiting list in the Orthodontic Department, Dental Faculty, UKM. All anterior teeth were measured by the same examiner at the largest mesio-distal dimension, using a digital caliper recorded up to 0.01 mm. Comparison between the 4 groups of malocclusion were made intra-arch using individual tooth size measurement and inter-arch using Anterior Bolton Index (ABI). Results: For the intra-arch assessment, Class II/1 had significantly the largest upper and lower anterior tooth size except for its upper canine and lower central incisor. Class III group had insignificantly the smallest mandibular anterior teeth compared to other malocclusion groups. For inter-arch assessment, Anterior Bolton Index (ABI) of all samples was 79.2 ± 3.94%. The highest ABI was noted in Class II / 2 of 80.3 ± 4.71%. However, no significant differences were found among the 4 malocclusion groups (p>0.05). Conclusion: Most of the anterior teeth in Class II division 1 were the largest of all. No significant difference in the inter-arch tooth size discrepancies were detected among all malocclusion groups.

Análise de Bolton: uma proposta alternativa para a simplificação de seu uso / Bolton analysis: an alternative proposal for simplification of its use

INTRODUÇÃO: as discrepâncias entre o tamanho mesiodistal dos dentes superiores e inferiores e seus efeitos sobre a oclusão têm sido relatados há muito tempo. O método proposto por Bolton para o diagnóstico de discrepância de tamanho dentário é, inegavelmente, um dos mais difundidos no meio ortodôntico, devido à sua relativa simplicidade. Entretanto, a aplicação desse método requer cálculos matemáticos e o uso de tabelas que, muitas vezes, inviabilizam a sua utilização durante a avaliação clínica. OBJETIVO: avaliar o método proposto por Wolford, que não requer o uso de tabelas, como alternativa ao método tradicional de Bolton. MÉTODOS: a amostra foi composta por 90 pares de modelos dentários iniciais de pacientes adultos, com diferentes más oclusões. A proporção entre os dentes inferiores e superiores foi calculada para cada paciente, resultando na obtenção de dois índices (a razão total e a razão anterior). Os índices foram obtidos por meio do método originalmente proposto por Bolton e por um método alternativo, composto por duas fórmulas (uma simplificada e a variação da mesma), que foram analisadas separadamente. RESULTADOS: comparadas ao método de Bolton, as fórmulas simplificadas mostraram uma tendência de superestimar as discrepâncias dentárias inferiores (total e anterior), embora em pequena proporção. CONCLUSÕES: ambas as fórmulas do método alternativo podem ser utilizadas em substituição ao método tradicional, uma vez que mostraram diferenças médias menores que 0,58mm quando comparadas ao método de Bolton, não apresentando, portanto, significância clínica.

INTRODUCTION: Mesiodistal size discrepancies of upper and lower teeth and their effect on occlusion have been related. Bolton's method for tooth size discrepancies is, undeniably, one of the most commonly-used methods in orthodontics because of its simplicity. However, the application of this method requires mathematical calculations and use of tables, which often prevents its clinical use. PURPOSE: Evaluate an alternative method for Bolton's analysis proposed by Wolford that does not require table information. MATERIAL AND METHODS: The sample was composed of 90 initial dental casts of adult patients, with different malocclusions. The ratio between the sum of widths of maxillary and mandibular teeth was calculated for each patient, resulting in the attainment of two indices: The overall ratio and the anterior ratio. Indices were calculated by Bolton's method and by an alternative method, using two different formulas (one simplified and a variation of the same formula) that were separately analyzed. RESULTS: In comparison with Bolton's method, the Simplified Formulas demonstrated a slight trend towards an overestimation of the inferior dental discrepancies (overall and anterior). CONCLUSION: Both formulas employed for the alternative method may be used to substitute the traditional method, since each demonstrated, on average, differences of less than 0.58 mm when compared with Bolton's method and no clinical significance.

Estudo biométrico em dentes de humanos / Biometric study of human teeth

OBJETIVO: determinar as dimensões biométricas de dentes humanos, nos sentidos mesiodistal, vestibulolingual e ocluso/inciso-cervical. MÉTODOS: utilizou-se uma amostra de modelos em gesso de 57 pacientes - 31 do sexo feminino (média de idade de 15 anos e 5 meses) e 26 do masculino (média de idade de 16 anos e 6 meses). A amostra foi previamente qualificada, adotando-se o critério das "seis chaves para a oclusão perfeita" de Andrews, e teve seus valores compatibilizados com as variações obtidas por Bolton. Dois examinadores usaram um paquímetro digital com as pontas originais (curtas) e outras modificadas (pontas longas). RESULTADOS E CONCLUSÕES: após os resultados serem submetidos aos testes estatísticos, constatou-se que os elementos dentários se mostraram simétricos nas arcadas dentárias em ambos os sexos. As dimensões dentárias são menores no sexo feminino, portanto, quando estudadas, devem ser separadas. Com os valores médios gerais obtidos, foi possível elaborar tabelas separadas quanto aos sexos, valores médios das três dimensões dentárias, porcentagem de ocorrência entre essas dimensões e seus respectivos desvios-padrão. Com esses valores foi possível desenvolver a denominada equação "C" e tabelas de percentis "C" e, com o auxílio de ambas, tornou-se possível aferir apenas uma das dimensões de um dente e encontrar as duas outras dimensões "prováveis" dos demais dentes das arcadas dentárias.

Objective: To determine the biometric dimensions of human teeth in the mesiodistal, buccolingual and occlusal/incisal-cervical directions. Methods: It was used a sample of dental casts from 57 patients, i.e., 31 females with a mean age of 15 years and 5 months, and 26 males with a mean age of 16 years and 6 months. The sample was previously qualified by adopting the criteria established by Andrews' six keys to normal occlusion, whose values were matched to the variations obtained by Bolton. Two examiners used a digital caliper with original (short) and modified (long) tips. Results and Conclusions: After statistical analysis of the data it was concluded that the teeth were shown to be symmetrical in the dental arches of both genders. Tooth dimensions are smaller in females than in males and should therefore be studied separately. Overall mean values were obtained and used to build tables distinguishing such dimensions according to gender. Mean values for the three tooth dimensions, occurrence rates of these dimensions and their standard deviations were also calculated. These values allowed the development of an equation called "C" equation as well as "C" percentile tables. With the aid of both, it became possible to measure only one dimension of a given tooth to find the other two "probable" dimensions of the other teeth in the dental arches.

Discrepancia dentaria de Bolton y finalización de ortodoncia: consideraciones clínicas / Bolton tooth size discrepancy and orthodontics finalization: clinical considerations

Las discrepancias entre el tamaño mesiodistal de los dientes superiores e inferiores, así como sus efectos sobre la oclusión han sido reportadas desde mediados del siglo XX. El objetivo de este estudio fue determinar la importancia de la aplicación del análisis de discrepancias dentaria de Bolton con finalidad ortodontica. Fueron seleccionados casos de pacientes de raza blanca de ambos sexos, con edades comprendidas entre 12 y 25 años. El análisis de las discrepancias dentarias fue realizado en la fase previa al tratamiento y posterior a la contención. Como criterio básico para la inclusión en la muestra de pacientes en el pre-tratamiento deberían presentar todos los dientes permanentes (de primeros molares a primeros molares del lado opuesto, en ambos arcos). Fueron eliminados los casos que presentaron dientes con grandes destrucciones, restauraciones inadecuadas y dientes mal posicionados donde no fue posible la medición adecuada entre los puntos de contacto. La medición del tamaño mesiodistal de los dientes se realizó con un caliper (Odin, Alemania), precisión de 0,01 mm, por un solo examinador, previamente calibrado para realizar este procedimiento. Se midió el diámetro mesiodistal mayor de todos los dientes. Las relaciones totales y anteriores fueron calculadas por las fórmulas respectivas, según lo propuesto por Bolton (1958). Al finalizar, los casos mostraron que una discrepancia dentaria de Bolton maxilar o mandibular por exceso o falta dentaria, puede ser compensada por la alteración en la forma del arco, dimensión vestibulolingual y por la inclinación axial de los dientes anteriores, utilizadas en conjunto o aisladamente en la arcada, sin perjuicio estético y funcional.

Discrepancies of the mesiodistal dimensions between upper and lower teeth as well as their effects on occlusion have been reported since the middle of the twentieth century. The aim of this study was to elucidate the importance of the applicability of the analysis of the Bolton tooth size discrepancy in the orthodontic finalizing. Cases involving Caucasian male and female patients aged between 12 and 25 years were selected for study. Analyses of the dental discrepancies were carried out before orthodontic treatment and after contention. Basically, only patients having all permanent teeth before treatment (with first molars in both arches) were included. Those cases of severely mutilated teeth, inadequate restorations, and tooth malalignment were ruled out because accurate measurement of the contacting points could not be performed. Measurement of the mesiodistal tooth dimension was performed by only one operator using a digital calliper of a resolution of 0.001 mm (Odin, Germany) which had been previously calibrated for such procedures. It was measured the largest mesiodistal diameter. Both previous and total relationships were calculated through their respective formulas according to Bolton (1958). The orthodontic finalisation showed that Bolton tooth size discrepancies involving either crowded dentition or lack of teeth can be compensated by mandibular or maxillary arch shape, buccal-lingual dimension, and axial inclination of the anterior teeth with no aesthetic or functional impairment.

A busca da estética em casos de discrepância ósseo-dentária / In searching of esthetic in case of tooth-size discrepancy

Em Odontologia, o desafio não é apenas produzir boa oclusão, mas obter boa oclusão com bom resultado estético. E a escolha da solução mais adequada depende das características específicas de cada caso e da interação com as especialidades afins devem ser consideradas na elaboração e execução do plano de tratamento. A ausência de proporcionalidade dimensional entre os dentes maxilares e mandibulares impossibilita a intercuspidação, overjet e overbite adequados, além de um bom resultado estético. Nos casos de discrepância ósseodentária estão indicados stripping ou acréscimo e abertura ou fechamento de espaço na arcada oposta. Nesses casos, as dificuldades envolvidas devem ser ponderadas. No caso clínico apresentado os recursos biomecânicos da Ortodontia e os benefícios da Dentística foram aplicados com sucesso.

In Dentistry the challenge is not to produce a good occlusion, but an aesthetic smile in a good occlusion. The choice of best solution depends on the specific characteristics of each case and the interaction with the similar specialties. The elaboration and execution of the treatment plan must be considered. The absence of dimensional proportionality between mandibular and maxillary teeth disables the intercuspation, overjet and overbite adjusted with a good aesthetic result. In cases of tooth-size discrepancy stripping or addition and opening or closing of space in opposite arch are indicated. In these cases, the involved difficulties and specific needs must be considered altogether. In the clinical case presented orthodontic biomechanic resources and the benefits of the Cosmetic Dentistry had been applied successfully.

Aplicação clínica da análise de bolton em dentística e ortodontia / Clinical application of the bolton analysis in dentistry and orthodontics

A discrepância de tamanho dentário ocorre em um número considerável de pacientes que procuram por tratamento ortodôntico, e pode influenciar de maneira negativa os objetivos do tratamento e os seus resultados finais, impedindo a busca da excelência na finalização do caso. Tal deficiência na finalização pode ser detectada e considerada na fase de diagnóstico e planejamento do tratamento, pela análise da discrepância de tamanho dentário. O artigo está ilustrado com o caso clínico de um paciente do sexo masculino, 13,2 anos de idade, que após a realização da análise de Bolton, constatou-se a discrepância de tamanho dentário, com proporção total igual a 95,3 (média de 91,3), demonstrando um déficit na arcada superior devido à anomalia de forma nos incisivos laterais superiores. Sendo assim foi planejado um tratamento multidisciplinar com a Ortodontia para devolver a oclusão e macroestética do sorriso e a Dentística para obter a microestética. Esse planejamento multidisciplinar permitiu o tratamento mais adequado e a excelência na finalização do caso. Portanto a análise de Bolton é uma ferramenta importante na fase de diagnóstico e planejamento do tratamento ortodôntico.

The discrepancy of dental size occurs in a considerable number of patients who search for orthodontic treatment and may negatively influence the treatment objectives and compromise its final results. This size deficiency can be detected and considered in the diagnosis and treatment plan phases through the analysis of tooth size discrepancy. This article illustrates a case report of a male patient, 13.2 years old, who had a tooth size discrepancy identified through the Bolton analysis with a total proportion of 95.3 (average of 91.3), demonstrating a deficit in the superior arch due to a shape anomaly of the superior lateral incisors. Thus, a multidisciplinary treatment course was planned including orthodontic, to reestablish occlusion and macro-esthetic elements of the smile; and restorative dentistry, to improve micro-esthetic quality. This multidisciplinary plan enabled a more adequate course of treatment and higher rate of overall success. Therefore, the Bolton analysis is an important tool in the diagnosis and orthodontic treatment planning phases.

What determines dental protrusion or crowding while both malocclusions are caused by large tooth size? / 대한치과교정학회지

OBJECTIVE: To examine the differences in lateral cephalometric characteristics between patients with dental protrusion and crowding in order to determine what factors affect dental protrusion or crowding while both malocclusion types are caused by large tooth size. METHODS: Twenty nine individuals with dental protrusion and 22 individuals with dental crowding were enrolled in this study. All subjects had larger teeth than average and Class I molar relationships. Craniofacial characteristics and hyoid bone positions were determined from lateral cephalograms and compared between the two groups. RESULTS: In the comparisons of craniofacial characteristics, the measurements indicating maxillary length and facial convexity showed greater values in the protrusion group than in the crowding group. Comparisons of hyoid bone positions showed that the hyoid bone was positioned more anteriorly and superiorly in the protrusion group than in the crowding group. CONCLUSIONS: The results of the present study indicate that some craniofacial characteristics and tongue position may affect the development of dental protrusion or crowding; when an individual has large teeth, dental protrusion or crowding might be determined according to maxillary growth and tongue position.