Does primary trauma lead to developmental defects in permanent teeth?

Abstract

Introduction A systematic review of existing evidence to determine if trauma in the primary dentition causes alteration in the development of the underlying permanent dentition.Data sources Six electronic databases (PubMed, Medline, MEDES, Scopus, Lilacs and Embase) were used to search a range of dental terms relating to dental trauma to locate studies between 1972-2020.Study selection Study selection was carried out by two authors by reviewing title, abstract and then full articles. A third author was consulted if consensus for inclusion was needed. Eligibility criteria included all scientific articles concerning sequalae to the human permanent dentition following trauma to the primary dentition. Only English, German and Spanish languages were included. For evaluation, the studies must have satisfied the following: a) minimum sample of 50 children to be representative; b) radiographic examination; and c) appropriate follow-up period up to permanent successor eruption.From 537 studies, 18 studies were identified for consideration in the review, comprising of 13 cross-sectional studies, two cohort studies and three case control studies.Data extraction and synthesis The Newcastle-Ottawa Scale was used to extract data and determine study quality. Only studies determined as high quality were included in the review. Four cross-sectional studies and three case control studies, totalling seven studies, were used. Data from these high-quality studies was summarised into table format.Results Large variation in study sample size existed from 138-753 traumatised teeth and 78-879 children. Both sexes were included in all studies and the children were aged between 0-17 years.Some studies found there was no difference in rate of trauma between girls and boys, while others found there was a higher incidence of trauma in boys than girls. The most frequently traumatised teeth were the upper primary central incisors. Whilst most studies covered all types of primary trauma, two only studied intrusion and one specified the type of primary trauma as luxation or fracture injuries.Whilst some of the studies concluded a higher frequency of defects to permanent teeth following primary intrusion trauma aged four and under, others showed no significant differences between the age of intrusion and the effect to the successor incisor.Enamel defects of the permanent teeth were the most common sequalae with a wide prevalence reported between 4.5-68.8%. Enamel defects were classified as hypoplasia and hypocalcification. Ectopic or altered eruption, crown or root dilacerations and odontoma development were observed less often, with the latter very rarely.Conclusions Primary tooth intrusion trauma causes the highest proportion of sequalae presenting as enamel defects. Younger patients experiencing primary trauma are more likely to obtain damage to the succeeding dentition. The existing quality of evidence is limited due to the observational nature of the studies available.