Aplicabilidad del método Tanaka-Johnston para la estimación del diámetro mesiodistal de caninos y premolares en pacientes de 12-18 Años / Applicability of the Tanaka-Johnston method for the estimation of the mesiodistal diameter of canines and premolars in patients of 12-18 years old

El método Tanaka-Johnston es utilizado mundialmente para predecir el diámetro de caninos y premolares no erupcionados por la conveniencia de no necesitar tablas ni radiografías para su uso. Sin embargo, durante los últimos años investigadores de varios países han demostrado que al ser utilizado en una población diferente para la que fue diseñado, puede sobrestimar o subestimar los valores. En Cuba, donde el patrón facial de la población difiere del ideal para este método, ha sido muy empleado, pero prácticamente no existen estudios donde se valide la confiabilidad o exactitud de las predicciones de este. Por tanto, el objetivo de esta investigación es determinar la aplicabilidad del método Tanaka-Johnston para la estimación del diámetro mesiodistal de caninos y premolares en pacientes de 12-18 años. Se desarrolló un estudio descriptivo y transversal desde junio de 2019 hasta enero de 2020 con una población de 140 pacientes de ambos sexos de entre 12 y 18 años de Cuba. Se efectuaron las mediciones de los anchos mesiodistales de los incisivos inferiores, todos los caninos y premolares. Se realizaron distribuciones de frecuencia a las variables estudiadas y los resultados se presentaron en tablas estadísticas. Para comprobar la existencia de diferencias significativas se utilizó la prueba estadística t-Student. Los resultados principales obtenidos fueron que el método Tanaka-Johnston tiende a sobrestimar los valores para el sexo femenino y subestimarlos para el masculino, ambos entre los 0,2 y 0,3 mm, pero esta diferencia no resulta significativa. Se concluye que el método Tanaka-Johnston puede ser aplicado en la población estudiada para la predicción del ancho mesiodistal de caninos y premolares no erupcionados.

The Tanaka-Johnston method is used worldwide to predict the diameter of canines and premolars not erupted for the convenience of not needing boards or x-rays for use. However, in recent years researchers from several countries have shown that when used in a different population for which it was designed, it can overestimate or underestimate the values. In Cuba, where the facial pattern of the population differs from the ideal for this method, it has been highly used, but there are very few studies where the reliability or accuracy of the predictions of the same is validated. Therefore, the objective of this research is to determine the applicability of the Tanaka-Johnston method for estimating the mesiodistal diameter of canines and premolars in patients aged 12-18 years. A descriptive and cross-cutting study was conducted from June 2019 to January 2020 with a population of 140 patients of both sexes between 12 and 18 years of age from Cuba. Measurements were made of the mesiodistal widths of the lower incisors, all canines, and premolars. Frequency distributions were made to the variables studied and the results were presented in statistical tables. The t-Student statistical test was used to verify significant differences. The main results obtained were that the Tanaka-Johnston method tends to overestimate the values for the female sex and underestimate them for the male, both between 0,2 and 0,3 mm, but this difference is not significant. It is concluded that the Tanaka-Johnston method can be applied in the population studied for the prediction of the mesiodistal width of unerupted canines and premolars.

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.

Applicability of Moyers analysis in mixed dentition: A systematic review

INTRODUCTION: Moyers analysis is widely used for analyzing mixed dentition, however, the accuracy of its theoretical probability tables has been recently questioned. Taking into consideration the fact the mixed dentition analysis is of paramount importance to precisely determine the space needed for alignment of canines and premolars, this research aimed at objectively assessing in the literature such an important step for orthodontic diagnosis. METHODS: A computerized search involving articles published on PubMed and Lilacs between 1990 and September, 2011 was conducted in accordance with the method described in the Cochrane 5.1.0 handbook. RESULTS: The research resulted in a sample composed of 629 articles. The inclusion criteria were: Articles using the Moyers analysis with a sample greater or equal to 40 patients. Conversely, the exclusion criteria were: Dental casts of patients with syndromes or oral cleft, researches conducted with a literature review, only, or clinical case reports and researches conducted before 1990. For this systematic review, 19 articles were selected. CONCLUSION: Based on the literature available, we can conclude that the Moyers mixed dentition analysis must be carefully used, since the majority of the articles analyzed showed that the probability of 75% was not as accurate as expected, leading to the need of adapting the probability levels depending on the study population.

INTRODUÇÃO: a análise de Moyers é amplamente adotada para a análise da dentição mista, porém, recentemente, a acurácia das suas tabelas de probabilidade está sendo questionada. OBJETIVO: sabendo-se da importância da análise da dentição mista, na determinação mais precisa possível do espaço necessário para o alinhamento de caninos e pré-molares, o objetivo dessa pesquisa foi avaliar de forma objetiva na literatura este importante passo do diagnóstico ortodôntico. MÉTODOS: foi realizado um levantamento computadorizado de artigos publicados entre os anos de 1990 a setembro de 2011 nas bases de dados PubMed e LILACS, segundo o método descrito no manual Cochrane 5.1.0. RESULTADOS: a estratégia de busca resultou em 629 artigos. Para ser selecionado, o artigo deveria utilizar a análise de Moyers e ter uma amostra superior ou igual a 40 pacientes. Os critérios de exclusão foram: modelos de gesso de pacientes com algum tipo de síndrome ou fissurados, pesquisas cuja proposta era apenas uma revisão da literatura ou apenas relato de um caso clínico, e pesquisas anteriores ao ano de 1990. Para essa revisão sistemática, 19 artigos foram selecionados. CONCLUSÕES: com base na literatura disponível, pode-se concluir que a utilização da análise de Moyers na análise da dentição mista deve ser utilizada de maneira cautelosa, pois, na maioria dos artigos avaliados, 75% não apresentou a acurácia desejada, necessitando de adaptações nos níveis de probabilidade, dependendo da população em estudo.

Prediction of the mesiodistal size of unerupted canines and premolars for a group of Romanian children: a comparative study

Objectives The aim of the present study was to develop an optimization method of multiple linear regression equation (MLRE), using a genetic algorithm to determine a set of coefficients that minimize the prediction error for the sum of permanent premolars and canine dimensions in a group of young people from a central area of Romania represented by a city called Sibiu. Material and Methods To test the proposed method, we used a multiple linear regression equation derived from the estimation method proposed by Mojers, to which we adjusted regression coefficients using the Breeder genetic algorithm. A total of 92 children were selected with complete permanent teeth with no clinically visible dental caries, proximal restorations or orthodontic treatment. A hard dental stone was made for each of these models, which was then measured with a digital calliper. The Dahlberg analyses of variance had been performed to determine the error of method, then the Correlation t Test was applied, and finally the MLRE equations were obtained using the version 16 for Windows of the SPSS program. Results The correlation coefficient of MLRE was between 51-67% and the significance level was set at α=0.05. Comparing predictions provided by the new and respectively old method, we can conclude that the Breeder genetic algorithm is capable of providing the best values for parameters of multiple linear regression equations, and thus our equations are optimized for the best performance. Conclusion The prediction error rates of the optimized equations using the Breeder genetic algorithm are smaller than those provided by the multiple linear regression equations proposed in the recent study. .

Comparison of three mixed dentition analysis methods in orthodontic patients at AKUH

To compare the actual sum of canine and premolars and that predicted from three mixed dentition prediction methods in orthodontic patients at the Aga Khan University Hospital [AKUH], Karachi. Cross-sectional comparative study. Orthodontic clinic at the Aga Khan University Hospital from June 2002 to December 2007. Data were collected using pretreatment records including orthodontic files and plaster casts of 121 orthodontic patients. Digital caliper was used to measure the mesiodistal widths of permanent teeth from 1st molar to 1st molar in mandibular arch, and central incisors and 1st molars in maxillary arch. The methods of Tanaka and Johnston, Moyers, and Bernabe and Flores-Mir were used to predict the mesiodistal widths of the canine and premolars. Comparison between the actual and predicted sum of the mesiodistal widths of canine and premolars was made for each prediction method, using paired sample t-test. There were 45 males and 76 females with average ages of 13.3 +/- 1.3 and 13.4 +/- 0.8 years respectively. For males statistically significant differences were found for Moyers at the 75th percentile and Bernabe and Flores-Mir method whereas for females only the Bernabe and Flores-Mir's method showed significant results. However, no significant difference was found in both genders for Tanaka and Johnston method. In the studied orthodontic patients for males Moyers 50th percentile and Tanaka and Johnston methods could be used; while for females Moyers 75th percentile and Tanaka and Johnston methods were applicable for mixed dentition analysis

Multiple abnormal unerupted mandibular permanent molar teeth: a case report / Molares mandibulares anormales no-erupcionados múltiples: reporte de un caso

Abnormal multiply unerupted permanent molars have long received the attention of anatomists and maxillofacial surgeons besides the other developmental teeth anomalies. This paper presents a clinical case of a 23-year-old male patient who was admitted to the department of maxillofacial surgery in faculty of dentistry in Gulhane Medical School with a six month history of pain at the rest position and during chewing and also tender on his right corpus of mandible. The impaction which resulted in eruption failure and anatomical dislocation of the normally developed three mandibular molar teeth was found. It was defined facial asymmetry on his right side in extra-oral examination. Diagnosis of multiple abnormal unerupted mandibular molar teeth was confirmed by panoramic and 3D CT images. The unerupted inverted tooth was the third molar which is positioned to basis of the mandible on the right side. In the other side, the first molar was placed on basis of mandible and located distoangulary. The second molar was located on middle of the left corpus mandible vertically. And also, the third molar was erupted mesioangulary. The arch-length was evaluated by the oral surgeon. Mesio-distal distance between the teeth was to be sufficient. Causes of impacted permanent teeth might have been influenced by local factors such as prolonged deciduous tooth retention, malposed tooth germs, but not causing arch-length deficiency and supernumerary teeth. Abnormalities such as those reported in the present case are significant during maxillofacial surgery.

Los molares permanentes anormales no erupcionados múltiples, además de otras anomalías del desarrollo de los dientes, desde hace tiempo han recibido atención de anatomistas y cirujanos maxilofaciales. Este artículo presenta un caso clínico de un paciente masculino de 23 años de edad, que fue admitido en el Departamento de Cirugía Maxilofacial de la Facultad de Odontología de la Escuela de Medicina Gulhane, con una historia de seis meses de dolor, en la posición de descanso y durante la masticación, así como dolor en su cuerpo mandibular derecho. Fue encontrada la impactación que resulta de la falla en la erupción y la dislocación de la anatomía normal del desarrollo en tres molares mandibulares. En el examen extraoral fue definida asimetría facial del lado derecho. El diagnóstico de molares mandibulares anormales no erupcionados múltiples fue confirmado por radiografía panorámica e imágenes de tomografía 3D. El diente invertido no erupcionado fue el tercer molar que se encontró en la base de la mandíbula en el lado derecho. En el otro lado, el primer molar se posicionó sobre la base de la mandíbula distoangularmente. El segundo molar se encontró verticalmente en medio del cuerpo mandibular izquierdo. También, el tercer molar erupcionó mesioangularmente. La longitud del arco fue evaluada por el cirujano oral. La distancia mesio-distal entre los dientes fue suficiente. Las causas de impactación de los dientes permanentes podrían haber sido influenciadas por los factores locales, tales como la retención prolongada de dientes deciduos o gérmenes dentales malposicionados, pero no fueron provocados por deficiencia de longitud del arco y dientes supernumerarios. Anomalías tales como las reportadas en el presente caso, son importantes en la cirugía maxilofacial.

Prismless enamel in human non-erupted deciduous molar teeth: a scanning electron microscopic study / Esmalte aprismático em molares humanos decícuos näo erupcionados: estudo ao microscópio eletrônico de varredura

Foram descritas a frequência, a estrutura e a espessura da camada de esmalte aprismático nas superfícies vestibular e lingual de molares decíduos näo erupcionados. Os dentes foram extraídos e mantidos em soluçäo de etanol a 70 por cento e, em seguida, desidratados, cobertos com ouro e examinados em um microscópio eletrônico de varredura JEOL, JSM-6.100. A camada aprismática foi observada nos terços oclusal, médio e cervical de todas as superfícies vestibular e lingual. Os cristais de hidroxiapatita seguiram um arranjo paralelo entre si e perpendicular à superfície do esmalte. Nenhuma diferença estatisticamente significante foi observada entre os terços oclusal, médio e cervical, que apresentaram uma espessura média de 7,257 µm

Principais transtornos ocasionados por dentes inclusos / Clinical and radiographic aspects related to the main perturbations caused by unerupted teeth

Säo apresentados os transtornos mais freqüentes ocasionados por dentes inclusos e suas soluçöes clínicas, além de se efetuar uma breve revisäo da literatura sobre o assunto. Em razäo do grande número de problemas que podem estar associados aos dentes inclusos e suas conseqüências nas diferentes especialidades, os autores sugerem que se façam proservaçöes radiográficas sempre que se detecte a presença de um dente incluso sem indicaçäo de remoçäo cirúrgica