Effects of antibiotics on the developing enamel in neonatal mice

Purpose Identifying factors causing Molar-Incisor Hypomineralization (MIH) is an ongoing challenge. Preterm infants, routinely treated with antibiotics in cases of suspected sepsis, are more commonly afected by dental developmental defects. This study aimed to investigate the efects of gentamycin and ampicillin on the developing enamel in neonatal CD-1 mice in vivo. Methods Neonatal mice were randomized into a study (n=36) and a control (n=35) group. Antibiotics were injected intravenously for 4 days. All mice were sacrifced after 15–18 days. Micro-CT was used to analyse the mineral density (MD) of the enamel and the proportion of the enamel object volume (vol%) in frst molars and incisors. Results We demonstrated a signifcantly lower vol% enamel in the maxillary (30.9% vs. 32.7%; p=0.004) and mandibular (32.5% vs. 34.6%; p=0.015) molars in the study group than in the controls. The incisors were divided into segments upon analysis. We demonstrated both lower vol% and lower MD of the enamel in most segments in treated individuals compared to controls (p Conclusion The reduced MD and vol% in the molars and incisors are likely to have been caused by the antibiotics given during tooth development. The presented analysis of teeth in neonatal mice with micro-CT could be a valid model for further research on dental developmental defects

p38 differentially regulates ERK, p21, and mitogenic signalling in two pancreatic carcinoma cell lines

Whereas the p38 MAP kinase has largely been associated with anti-proliferative functions, several observations have indicated that it may also have positive effects on proliferation. In hepatocytes, we have found that p38 has opposing effects on DNA synthesis when activated by EGF and HGF. Here we have studied the function of p38 in EGF- and HGF-induced DNA synthesis in the two pancreatic carcinoma cell lines AsPC-1 and Panc-1. In Panc-1 cells, the MEK inhibitor PD98059 reduced EGF- and HGF-induced DNA synthesis, while the p38 inhibitor SB203580 strongly increased the basal DNA synthesis and reduced expression of the cyclin-dependent kinase inhibitor (CDKI) p21. In contrast, in AsPC-1 cells, EGF- and HGF-induced DNA synthesis was not significantly reduced by PD98059 but was inhibited by SB203580. Treatment with SB203580 amplified the sustained ERK phosphorylation induced by these growth factors and caused a marked upregulation of the expression of p21, which could be blocked by PD98059. These results suggest that while DNA synthesis in Panc-1 cells is enhanced by ERK and strongly suppressed by p38, in AsPC-1 cells, p38 exerts a pro-mitogenic effect through MEK/ERK-dependent downregulation of p21. Thus, p38 may have suppressive or stimulatory effects on proliferation depending on the cell type, due to differential cross-talk between the p38 and MEK/ERK pathways

Extraction of first permanent molars severely affected by molar incisor hypomineralisation: a retrospective audit

Abstract Aim The aim of this study was to evaluate possible spontaneous space closure after extraction of first permanent molars in children and their eventual need for orthodontic treatment. Methods Twenty-seven children with at least one first permanent molar planned for extraction were enrolled in the study. The children were referred to the Department of Paediatric Dentistry, University of Oslo, between 2009 and 2017. All extracted teeth were severely affected by Molar Incisor Hypomineralisation and/or caries. The children and their parents had consented to extraction and follow-up. Data were analysed with SPSS 26. Results The age of the children was between 5.5 and 12.1 years (mean 8.7) at extraction. The mean follow-up time was 3.2 years (range 1.1–6.3). Sixteen children (59.3%) had all four molars extracted, five (18.5%) had three, five had two and one had one molar extracted. In the maxilla, the second permanent molar had erupted in the place of the first molar in all the children, and none of them needed orthodontic space closure. In the mandible, eight children (29.6%) needed orthodontic treatment to close the spaces after extraction. In three children, the second molar was not yet erupted and treatment need was not settled. Conclusion Extraction of severely affected first permanent molars before the eruption of the second molar is a treatment option causing little additional treatment in the majority of cases

Knowledge, experience and perception regarding molar incisor hypomineralisation (MIH) among dentists and dental hygienists in Oslo, Norway

Abstract Aim The aim of this study is to gather baseline information on knowledge, perceptions, clinical experience and treatment options regarding MIH among dental care providers in Oslo, Norway, before a larger epidemiological study. Methods An electronic questionnaire was distributed to dentists ( n  = 88) and dental hygienists ( n  = 47) working in the Public Dental Service (PDS) in Oslo. The questionnaire consisted of five sections related to sociodemographic, clinical experience, perceptions, clinical management and preferences for further training. Descriptive statistics with chi-squared test was used, and level of statistical significance was set to 5%. Results Replies were obtained from 74.1% ( n  = 100) after two reminders. All respondents encountered MIH in their practice. The respondents’ perception of the prevalence of MIH in Oslo varied. The majority felt confident when diagnosing MIH (86%). The clinicians qualified in the last 10 years felt more confident than those who had qualified earlier ( p  = 0.016). Most were self-confident when treating these patients (68.3%), however, nearly all (88%) agreed that MIH was a clinical problem. The clinician’s treatment of MIH varied. Difficulties achieving adequate local anaesthetic (71.4%) and the child’s behavioural problems (84.1%) were treatment barriers for the dentists. Approximately two thirds (69%) would like further training, in particular on the aetiology (70%), diagnosis (57%) and treatment (77%) of the developmental disorder. Conclusion All clinicians were familiar with the diagnosis of MIH and experienced the condition to be a clinical problem. Continuing education on aetiology, diagnosis and treatment of MIH is requested by dental health personnel

Molar incisor malformation in six cases: description and diagnostic protocol.

OBJECTIVE The term molar-incisor malformation (MIM) has recently been presented in the scientific literature, where it is described as a condition with localized impaired root development. Here we present 6 recently discovered cases referred to our departments. STUDY DESIGN The patients were enrolled in the study after referral and were examined clinically and radiologically. Two extracted teeth were further examined with micro-computed tomography or microscopy. RESULTS Affected teeth were first permanent molars with hypoplastic roots, narrow pulp chambers, and a hypercalcified dentine layer cervical to the pulp chamber. Two of the cases also had cervical constrictions on the upper incisors. The patients were 8 to 12 years of age and healthy, but had experienced serious medical conditions of the head and neck region in their first year of life. Some of the cases had been referred because of acute infection and pain. CONCLUSION In 5 out of 6 patients, severe health problems in the head and neck region early in life may have been associated with root malformation in molars and incisors. Patients with MIM need to be followed closely, and extractions should be planned at the right time to avoid unnecessary infection and pain in addition to orthodontic problems

Long-Term Effects of a Randomized Maternal Education Trial in Rural Uganda: Implications for Child Oral Health

The aim was to examine oral health among 5–6-year-old children whose mothers participated in a 6 months’ cluster-randomized education trial in rural Uganda starting when their children were 6–8 months old. The education focused on nutrition, oral hygiene, and child stimulation. In the current follow-up study, 357/511 (70%) children from the original trial were available for data collection (200 in the intervention and 157 in the control group). Molar caries was assessed on intraoral photographs. Children and/or caregivers answered a WHO health questionnaire for collection of oral data. Dental practices were compared between the intervention and control group using multilevel mixed effect logistic regression accounting for clustering. The children in the intervention group had less caries compared with the control group: 41% versus 60% (odds ratio [OR] 0.46; 95% confidence intervals [CI] 0.24–0.86, P = 0.02). The use of toothbrush to clean teeth was more frequent in the intervention than in the control group: 66% versus 38% (OR 3.39; 95% CI 1.54–7.45, P = 0.003), as was high teeth-cleaning frequency: 74% versus 62% (OR 1.72; 95% CI 1.09–2.69, P = 0.02). Self-reported problems such as toothache (10% versus 19%), difficulty biting (12% versus 24%) and chewing food (8.5% versus 18%) were significantly less frequent among children in the intervention compared with the control group. No significant differences were found in dietary habits. Our data shows that an educational intervention adjusted to a low-resource setting, provided in infancy, resulted in improved oral hygiene and reduced development of dental caries among children aged 5–6 years