Indicators of jawbone asymmetry through analysis of panoramic radiographs.

AIM: To assess the degree of jawbone asymmetry by drawing vertical lines on digital panoramic radiographs of paediatric patients with right or left unilateral cross-bite. STUDY DESIGN: The sample consisted of 217 paediatric patients of both genders, aged 6-9 years. A set of vertical lines was drawn on the side of the mandible with the cross-bite and on the side without the cross-bite, using software program tpsDigs version 2. Subsequently, the differences in the measurements of the two sides were determined through statistical analysis. RESULTS: Analysis of the vertical jaw lines on the radiographic bite indices indicated, in every case, quantifiable differences between the side with the cross-bite and the side without the cross-bite. The differences between vertical variables, related to the heights of the mandible body and the condyle, were statistically significant (p>0.005) for the whole sample and both genders. Statistically significant differences in the heights of the mandible body were found for all the age groups (6 to 9 years old), except for the 9-year-old group, which registered differences in the variables of condylar height. CONCLUSION: Throughout the sample and regardless of the side affected by cross-bite, the vertical variables corresponding to the total height of the ramus were always smaller on the side with the cross-bite. Gender did not affect the results obtained and age influenced some of the mandible's vertical heights.

A study on the chronology and sequence of eruption of primary teeth in Spanish children.

AIM: The aim of this study is to determine the timing of primary teeth eruption in Spanish children, and to distinguish gender and arch differences. MATERIALS AND METHODS: A cross-sectional study was performed on primary teeth eruption in a sample of 1,250 children (623 girls and 627 boys) from the Region of Madrid aged between 3 and 42 months. The clinical emergence of teeth was taken to estimate the mean ages of primary teeth eruption. The t test was used to analyse gender and arch differences. RESULTS: The process of primary dentition lasted 22.28 months, and statistically significant differences were found in the eruption of homologous contralateral teeth. The first molars and maxillary lateral incisors erupted earlier in girls than in boys, with no statistically significant chronological differences. The central incisors and second molars erupted first in the mandibular arch, while the lateral incisors, canines and first molars erupted first in the maxilla. A greater chronological difference was found between the lateral incisors, which erupted more than 8 months earlier in the maxilla than in the mandible. CONCLUSIONS: In the overall sample, the first tooth to erupt was the lower right central incisor at 10.96 ± 1.88 months, and the last was the upper left second molar, at 33.24 ± 4.35 months, symmetry was found in the eruption of the deciduous teeth. The greatest chronological difference was observed in the lateral incisors, with the upper ones erupting more than 8 months before the lower ones. Although statistically significant gender differences were found, they were considered clinically irrelevant.

Diastemas in primary dentition and their relationships to sex, age and dental occlusion.

AIM: The prevalence of interincisive and primate spaces in the primary dentition, relating them to age and sex, was studied. An analysis was made as to what extent various occlusal aspects of the arches affect the existence of spacing. MATERIALS AND METHODS: A population of 267 children, 153 males and 114 females, aged 2.2-8.2 years, was evaluated. All were white Caucasian, apparently healthy and lacking any congenital malformations; they had complete primary dentition and no erupted permanent teeth, without existing dental malformation and not having undergone any type of orthodontic treatment. Cast models were fabricated from impressions taken of all the children. Tooth sizes and interdental spaces were measured on these models and the various occlusal aspects were noted. RESULTS: The prevalence of spacing was high in the primary dentition, being independent of the chronological age of each child. Spacing was more frequent in males than in females. The presence or absence of spacing was not directly related to occlusion except in cases of posterior cross-bite, where it was less frequently, and open-bites, in which spaces appeared more often than usual. CONCLUSION: Spaces in the primary dentition were very common among the population studied and more frequent in male children than in females. Primate spaces were more frequent at the earliest ages, but chronological age had no influence on the presence of interincisive spacing. The lack of the spaces in the maxillary arches, typical of the primary dentition, prevailed among individuals with posterior cross-bite, contrary to what normally happens in the rest of the population.