RESUMO
BACKGROUND: The conicity of the root canals of primary teeth is an important measure for endodontic therapies. However, determining this conicity depends on the methods employed, which requires further investigation. AIM: The aim of this study was to determine the conicity of the root canals of the upper and lower primary second molars using nanotomography (nCT). DESIGN: An in vitro study was performed using nine primary second molars, both upper and lower, subjected to nCT. Comparisons between the diameters of root canals were performed between the thirds (cervical-D0, middle-D5, and apical-D7). The conicity (%) was determined for each root canal from cervical to apical. Data were statistically analyzed with a significance level of 5%. RESULTS: The conicity ranged from 2% to 8% for the upper primary second molars. Significant differences in root canal diameter between the thirds (D0, D5, and D7 points) were observed in the mesio- and distobuccal roots (p < .05), but not in the palatal roots (p > .05). For the lower primary second molars, the conicity ranged from 2% to 17%, as well as significant differences in root canal diameter between the thirds (D0, D5, and D7 points) were observed in all roots (distal, mesiobuccal, and mesiolingual; p < .05). CONCLUSION: The conicity of the upper primary second molars was different from that of the lower ones, which showed a greater variability.
RESUMO
Introdução: a Tomografia Computadorizada Cone-beam(TCC8) é uma ferramenta útil que permite estudar a ATMcom precisãoe em três dimensões do espaço. Proposição: o objetivo da presenteinvestigação foi avaliar e determinar as variações anatômicas e posicionaisda ATM por cada tipo facial vertical. Métodos: foi selecionada umamostra de 55 tomografias em máxima oclusão de pacientes adultosjovens entre 15 e 35 anos: 15 com tipo facial longo, 15 com tipo facialmédio e 25 com tipo facial curto, sem tratamento prévio de Ortodontiae com aparente simetria facial. Foram analisadas as imagens dos côndilosdo lado direito mediante o software EZ Implant para estabelecera correlação entre as variáveis largura condilar, longitude condilar,distância côndilo fossa superior, altura da eminência articular, ânguloda eminência articular, posição vertical e anteroposterior do côndiloem cada tipo facial vertical. As diferenças entre as médias para cadauma das variáveis em cada tipo facial vertical foram avaliadas por meiodos testes estatísticos Anova, Kruskal Wallis e qui-quadrado, comocorrespondia. Resultados: encontraram-se diferenças significativasentre o tipo facial curto e longo em relação à distância côndilo fossasuperior (p < 0,05) e com respeito à altura da eminência articular(p < 0,01). Conclusão: a distância superior côndilo fossa e a alturada eminência articular apresentam variações de acordo ao tipo facialvertical, encontrando-se a distância superior côndilo fossa e a alturada eminência articular aumentadas no tipo facial curto e diminuídasno tipo facial longo.
Introduction: Cone Beam Computed Tomography (CBCT),is a useful tool for an accurate and three dimensional study of TMJ.Objective: the purpose of this study was to assess and determine theanatomical and positional changes of the TMJ depending on verticalfacial type. Methods: a sample of 55 tomography scans in maximumocclusion of patients aged 15 to 35 years: 15 long facial type, 15medium facial type and 25 short facial type, no previous orthodontictreatment and apparent facial symmetry were selected. Right condylesimages were analyzed on fZ Implant Software to establish correlationbetween variables condylar width, condylar length, superior condylefossadistance, height of articular eminence, articular eminence angle,vertical and anteroposterior position of the condyle by vertical facialtype. Differences among the means for each of the variables accordingto the vertical facial type were evaluated by Anova Kruskal Wallis andChi square statistical tests, as appropriate. Results: significant differenceswere found among the short and long facial type with respectto superior condyle fossa distance (p < 0.05) and with respect to theheight of the articular eminence (p < O.01). Conclusions: there is a statisticalsignificant variation among the superior condyle-fossa distanceand articular eminence height with vertical facial type, as the superiorcondyle-fossa distance and articular eminence height increased in theshort facial type and decreased in long facial type.
