Distribution of School Children Based on the Type of Terminal Plane in Primary Dentition: A Study among 3- to 5-year-old Children in Chennai, Tamil Nadu, India

Malocclusion in deciduous dentition: a cross-sectional study in a Portuguese preschool population

PURPOSE

To determine the prevalence of malocclusion in Portuguese preschool children, to characterise occlusion in the deciduous dentition, and to study the relationship between malocclusion, sex, and age.

METHODS

This cross-sectional study included 3-6 years old children, from 25 randomly selected kindergartens from the Lisbon district. Data were collected through an oral examination. Malocclusion was defined as the presence of any type of occlusion anomaly (anterior crossbite, edge-to-edge, increased overjet, open bite, deep overbite, posterior crossbite, scissor bite), spacing anomaly (crowding), or dentition anomaly (supernumerary teeth, agenesis, malformations). Canine class, terminal plane of the deciduous second molars and type of Baume arch were also recorded. Statistical analysis included descriptive and chi-squared test (α = 0.05).

RESULTS

The sample included 426 children with a global prevalence of malocclusion of 60.6%. Occlusion anomalies were the most prevalent (59.2%), the most frequent being deep overbite (27%), increased overjet (22.1%) and posterior crossbite (14.1%). Crowding had a prevalence of 1.6% and agenesis of 1.4%. Class I canine (57.3%), straight second molar terminal plane (60.1%) and type I Baume arch (53.3%) were the most common. The mean overjet was 2.6 mm (sd = 2.1) and the mean overbite was 2.2 mm (sd = 2.1). Age was associated with the presence of occlusion anomalies (p = 0.03), and increased overjet prevalence was found to be higher in girls (p = 0.03).

CONCLUSIONS

The prevalence of malocclusion was high, with occlusion anomalies being the most prevalent. It is important to identify modifiable risk factors associated with malocclusion to prevent this condition in both the deciduous and permanent dentitions.

Evolution of the Terminal Plane from Deciduous to Mixed Dentition

(1) Introduction: Correct development and growth of the dental arches and occlusion in the deciduous dentition is crucial for physiological occlusion in the permanent dentition. The present study evaluates the evolution of the terminal plane and canine occlusion class in the same children from deciduous to mixed dentition. (2) Materials and methods: The study included 257 children (164 girls and 93 boys) aged 3-5 years in the first phase and 8-10 years in the second phase. The chi-square test was used for the comparison of qualitative variables, while analysis of variance (ANOVA) or the Mann-Whitney U-test, Kruskal-Wallis test, and Wilcoxon test were used in the case of quantitative variables, as applicable. Statistical significance was considered for p < 0.05. (3) Results: The most common terminal plane in the first phase of the study was a bilateral flush plane (70%), followed by distal and mesial, with few differences between them. In the second phase, the most common terminal plane was mesial, followed by bilateral flush and distal. There were no statistically significant differences according to gender. Canine occlusion in the first phase was predominantly bilateral class I, followed by class II and class III. Similar results were recorded in the permanent dentition, except for a lesser percentage of children with canine class II. Molar occlusion in the second phase was predominantly class I, followed by half cusp class II and full cusp class II and class III. (4) Conclusions: The present study shows that knowing the age range in which maximum dental development and growth in both arches occurs may contribute to avoiding malocclusions and the possible need for orthodontic-orthopedic treatment, resulting in improved outcomes and greater stability.

The prevalence of different types of occlusal relationships based on the type of terminal plane in primary dentition: a study among 3- to 6-year old children in Tbilisi, Georgia

Background. Primary dentition takes the most important role in the development of permanent dentition. Primary second molars determine the eruption and position of permanent first molars. Early diagnosis and treatment could prevent the establishment of occlusal anomalies and deformities, therefore this study aimed to collect data about the prevalence of malocclusions based on the deciduous second molar terminal planes among the Tbilisi preschoolers.

Methods. A total of 396 children aged 3-6 years, with an equal number of male and female subjects, were examined in kindergartens drawn from ten districts of Tbilisi, using the PPS (probability proportional to size) method. The relationship between distal surfaces of primary second molars was evaluated and recorded according to Baume’s classification. The significance level is 0.05 for all statistical tests.

Results. Out of investigated preschoolers, 52.7% showed the flush terminal plane, followed by the distal step in 21.2% and mesial step in 26.1% of cases. There were no significant differences in genders. The most prevalent relationship between deciduous second molars was the flush terminal plane, with equal distribution in all age groups. The frequency of distal step decreased with age, more frequently recorded in the 3 to 4 year age group. The mesial step was mostly recorded in 3-4 and 5-6 year groups.

Conclusion. The flush terminal plane is the most frequent molar relationship, followed by mesial and distal step. Prevalence of distal mesial step significantly decreased with age, while mesial step relationship showed the tendency to increase. The flush terminal plane showed little change with age.