Dental Anomalies and Oral Health in Children with Nonsyndromic Clefts in Latvian Population and Their Association with Genetic Changes. Summary of the Doctoral Thesis

Abstract

Cleft lip and palate is one of the most common congenital malformation in maxillofacial region. The etiology of clefts are complex, involving both genetic and environmental factors. Dental anomalies in children with congenital clefts occure more often, they are considered as an additional clinical marker for determining the risk of clefts. One of the most common oral disease is dental caries. There is increasing research into genetics relating to dental caries and genes involved in caries susceptibility. The aim of this study is to investigate the types of dental anomalies and determine the oral health status of children with nonsyndromic congenital clefts in Latvia and their association with genetic markers rs2240308, rs11867417, rs9929218, rs642961, rs11362, rs1800972. This study is important as it has provided novel data about dental anomalies and oral health in children with nonsyndromic congenital clefts in Latvia as well as studied specific genetic markers in association with both dental anomalies and dental caries. The study consisted of three parts; the first, a retrospective analysis of 126 clinical charts for children with nonsyndromic clefts. It shoved that more dental anomalies were seen in children with bilateral (87.5%) and unilateral (75%) cleft lip and palate. The most common dental anomalies werehypodontia (29.37%) and microdontia(28.57%). The second part was the assesment of oral health evaluating the presence of dental caries, plaque and gum bleeding. Oral health was evaluated in 171 children with nonsyndromic clefts. This was compared to the control group of 196 children inthree different age groups (2 – 3, 6 – 7 and 11 – 12 year olds) according to the bite development. Overall, the prevalence of caries in cleft group children was lower compared to the control group. Caries intensity of 2 – 3 year old children with clefts was lower (dmf=3.49) compared to control group (4.78). In the 6 – 7 year old group caries intensity was higher and more filled teeth were present in the cleft group. In the 11 – 12 year old group caries intensity was similar in both groups. The plaque and bleeding index in both cleft and control groups was similar, except for plaque index in the 2 – 3 year old children and bleeding index in the 6 – 7 year old group which was less in the cleft group compared to the control group. When assessing oral health influencing behavioural factors using parental questionnaires, no specific factors were identified. The third part of this study was the identification of genetic markers associated with both, dental anomalies (rs2240308, rs11867417, rs9929218, rs642961), and dental caries (rs11362, rs1800972).The research identifiedIRF6(Interferon Regulatory Factor 6) genegenetic markers rs642961 significant association with dental anomalies and nonsyndromic clefts.This marker’s A allele was particularly associated with an increased risk of clefts. DEFB1(Defensin beta 1) gene genetic markers rs11362 studies identified association with caries in children with nonsyndromic clefts. In addition this gene’s expression in the oral cavity may be associated with an individual’s susceptibility to the dental caries. The results of this study provides insight in this complex multifactorial pathology and the role of possible genes involved. A multidisciplinary approach between health professionals from Cleft lip and palate centres and other professionals involved in the care is essential in order to improve care for the children with congenital nonsyndromic clefts.