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

INTRODUCTION

Childhood is the mirror that reflects the propensity of adulthood. Primary dentition is an indicator of potentially perfect permanent dentition. The function of primary dentition includes maintenance of the occlusion and space for the permanent dentition in addition to mastication. The primary dentition is complete with the eruption of the second primary molars, which means that the location for the eruption of the permanent teeth in the future has already been determined at this stage.¹

Malocclusion is a condition that deflects from the normal relation of the teeth to the other teeth in the same arch and the teeth in the opposing arch. Malocclusion in primary dentition is classified based on terminal planes as follows: (1) flush terminal plane—the distal surfaces of the upper and lower second primary molars are in the same vertical plane in centric occlusion; (2) distal step—the distal surface of the lower second primary molar is more distal to that of the upper in centric occlusion; and (3) mesial step—the distal surface of the lower second primary molar is more mesial to that of the upper in centric occlusion.²,³ The terminal plane relationship is used as a guide to determine the future interocclusal relation of the erupting first permanent molars. While functionally insignificant at this time, this relationship can greatly influence the position of the first permanent molars later, as the eruption path of the first permanent molars is guided by the distal surface of the distal root and tooth crown of the second primary molar.¹

Many studies^4–6 were performed to know the prevalence of malocclusion among school children in India. Occlusion in primary dentition plays a major role in determining the occlusion of the permanent dentition. Hence, it is important to have a baseline data of primary malocclusion as future developing malocclusion can be prevented in earlier stage. Literature on the prevalence of primary malocclusion among school children in Chennai population is scarce, and hence, this study was carried out to assess the prevalence of primary malocclusion based on the type of terminal planes among school-going children in Chennai city, Tamil Nadu.

MATERIALS AND METHODS

RESULTS

Among the total 814 children, 528 males and 286 females were examined and assessed for prevalence of different types of primary malocclusion. Table 1 shows that of the 814 population, 441 (54.1%) exhibited flush terminal plane, mesial shift was seen in 43.7%, and distal step in 17 (2.1%), respectively.

It can also be elucidated from Table 1 that the flush terminal plane was found to be more prevalent in both males (56.8%) and females. There is no statistical difference between primary malocclusion based on gender.

DISCUSSION

Epidemiological studies to document the occlusion in primary dentition in various populations are important because primary occlusion determines the future occlusion and often reflect the need for preventive and interceptive orthodontic treatment.⁹

Bishara et al.¹⁰ conducted a study to describe the changes in the molar relationship from the deciduous dentition to the permanent dentition and reported that the cases 56% of cases with flush terminal plane turned to class I occlusion and 44% to class II occlusion. Children with distal step developed class II permanent malocclusion and recommended that the treatment should be started at an earlier stage as there is less chance of self-correction. Cases with mesial step developed class I permanent molar relationship; however, there are chances with class III molar relationship depending on the magnitude of the mesial step.

The present study was conducted to know the prevalence of primary malocclusion among the school-going children in Chennai, Tamil Nadu, as there is scarcity of literature in this population and to create an awareness about malocclusion thereby helping them to prevent the upcoming aftermath. From this study, it is observed that flush terminal plane (54.05%) was the most prevalent type of primary malocclusion. Higher prevalence of mesial step (43.73%) was also reported in the present study. The distal step is the least common in the present study (2.08%). This is in accordance with Indian studies conducted by Hegde et al.,⁴ Bhat et al.,⁵ and Shavi et al.⁶

This study provided insights about the occlusion on primary malocclusion based on the terminal planes alone. There are other parameters that also determine the development of future malocclusion. This can be the limitation of the present study. Further longitudinal studies can be undertaken considering the various occlusal parameters to describe the changes from primary occlusion to permanent malocclusion in this population.

To conclude, the signs of future malocclusion is found to be high. Hence, early preventive and interceptive measures are necessary to reduce the prevalence of future developing malocclusion and further adverse effects.

REFERENCES

1. Sriram CH, Priya VK, Sivakumar N, et al. Occlusion of primary dentition in preschool children of Chennai and Hyderabad: A comparative study. Contemp Clin Dent 2012;3(1):31. DOI: 10.4103/0976-237X.94543.

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3. Forster TD. A Textbook of Orthodontics,London, UK: Blackwell Scientific Publications; 1990. p. 55.

4. Hegde S, Panwar S, Bolar DR, et al. Characteristics of occlusion in primary dentition of preschool children of Udaipur, India. European journal of dentistry. 2012;6(1):51.

5. Bhat SS, Rao HA, Hegde KS, et al. Characteristics of primary dentition occlusion in preschool children: an epidemiological study. Int J Clin Pediatr Dent 2012;5(2):93–97. DOI: 10.5005/jp-journals-10005-1143.

6. Shavi GR, Hiremath NV, Shukla R, et al. Prevalence of spaced and non-spaced dentition and occlusal relationship of primary dentition and its relation to malocclusion in school children of Davangere. J Int Oral Health 2015;7(9):75–78.

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8. Peter S. Essentials of Public Health Dentistry. 5th ed., Survey procedures in dentistry. India: Arya; 2013. p. 391.

9. Mtaya M, Brudvik P, Åstrøm AN. Prevalence of malocclusion and its associated factors among pre-schoolchildren in Kinondoni and Temeke Districts, Tanzania. Tanzan J Health Res 2017;19(2):1–9.

10. Bishara SE, Hoppens BJ, Jakobsen JR, et al. Changes in the molar relationship between the deciduous and permanent dentitions: A longitudinal study. Am J Orthod Dentofacial Orthop 1988;93(1):19–28. DOI: 10.1016/0889-5406(88)90189-8.