Odontoblast markers and dentine reactions in carious primary molars with and without hypomineralised enamel defects

Background: Wnt/β-Catenin signalling and DMP1 have key roles in tertiary dentinogenesis. Aim: To compare the relationship between remaining dentine thickness (RDT), tertiary dentine thickness (TDT), β-catenin and dentine matrix protein 1 (DMP1) in carious second primary molar teeth with normal (SPM) and hypomineralised enamel (HSPM). Design: Extracted carious SPM and HSPM were fixed, sectioned (5 μm) and stained with haematoxylin and eosin or with indirect immunofluorescence for β-catenin and DMP1. Image analysis was performed to determine RDT, TDT, β-catenin and DMP1 intensity in the odontoblast layer and dentine-pulp complex. Results: Carious SPM (n = 11; mean RDT = 1536.1 μm) and HSPM (n = 12; mean RDT = 1179.9 μm) had mean TDT 248.6 μm and 518.1 μm, respectively (P =.02). There were no significant differences in intensity values in the odontoblast layer and dentine-pulp complex for β-catenin and DMP1 for both groups. Conclusion: There was no observable variation in Wnt/β-catenin and DMP1 expression between HSPM and SPM despite a statistically significant twofold increased TDT in HSPM compared with SPM that had similar RDT. Thus, the observed increased TDT in HSPM is more likely due to an earlier onset of repair processes rather than an amplified response to caries

Medical and dental characteristics of children with chromosome 22q11.2 deletion syndrome at the Royal Children's Hospital, Melbourne

Background: Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a multifaceted syndrome with a variable phenotype. Few studies have described the associated dental characteristics and their relationship with medical co-morbidities; and no Australian data exist. Aim: To determine the clinical manifestations and correlations between oral and medical conditions in children with 22q11.2DS. Design: A retrospective observational study. Children genetically diagnosed with 22q11.2DS at the Royal Children's Hospital Melbourne were selected; their medical and dental characteristics were collated and analysed. Results: The study population (n = 57; mean age 11.5 years, range 2-27 years) experienced a range of medical conditions involving multiple medical systems; of whom 44 (77.2%) had caries experience, 7 (12.3%) developmentally missing teeth, and 31 (54.4%) developmental defects of enamel (DDE). Smaller proportions of primary teeth were affected by DDE in children with congenital heart disease (2.2% vs 9.7%; P = .02), and cardiac surgery (0.2% vs 9%; P = .001). Conversely, children with hypoparathyroidism (n = 2) had significantly higher proportions of primary teeth affected by DDE (27.5% vs 4%; P = .02). Conclusions: Significant associations existed between medical conditions (congenital heart disease, history of cardiac surgery, and hypoparathyroidism) and primary dentition DDE in children with 22q11.2 DS