Dottorato in TECNOLOGIE INNOVATIVE NELLE MALATTIE DELLO SCHELETRO,
DELLA CUTE E DEL DISTRETTO ORO-CRANIO-FACCIALE

Titolo della tesi: Genetic and molecular study on patients with dental anomalies

AIM: The aim of the following genetic and molecular study is to investigate the molecular basis of the palatal impactions of the maxillary canine, and in particular to study the role of miRNAs. The study of the impaction of the maxillary canine was carried out through DNA extraction in selected cases, with the ultimate aim of identifying the role of non-coding elements (miRNA) in the etiology of the phenotype and evaluating any correlations between dental and skeletal anomalies. MATERIALS AND METHODS: A sample of 25 subjects in the Orthodontic Department of “La Sapienza- University of Rome” (UOC) was evaluated. Saliva samples were taken from the selected subjects using special collection and conservation kits and salivary DNA was extracted, amplified, and sequenced. We collected a list of 82 miRNAs potentially associated with the development and eruption of dental elements, based on literature data. Of these 82 miRNAs, eight were selected (miR181B2, miR138-1, miR146A, miR155, miR181B1, miR182, miR29B1, miR138-2), as they are most involved in the eruption anomalies of the dental elements. Pearson's chi-square test was performed to evaluate the presence of any correlations with clinical and radiographic variables. For each test, statistical significance was declared with a p≤ 0.05. RESULTS: Three variants were identified for the following miRNAs: one for miR-146A (rs2910164) and two for miR-182 (rs76481776 and rs4541843). A statistically significant association was found between miR-146A and the following variables: lateral incisor abnormalities: p = 0.0455; ponticulus posticus: p = 0.0285; bridging of the sella turcica: p = 0.0455. CONCLUSION: The results of the present study highlight the role of miRNAs in the developmental pathways that regulate the eruption of dental elements, mainly targeting the expression of key genes of these processes, in a complex and integrated mechanism of regulation of cellular signaling networks. However, further studies are needed, with a larger sample size, conducted through gene expression analysis, sequencing screening and in vitro functional approaches, in order to evaluate the potential role of miRNAs in maxillary canine impaction.