Melbourne Dental School - Theses
Permanent URI for this collection
Search Results
1 - 1 of 1
-
ItemMolar-incisor hypomineralisation: perception, clinical characteristics and associated risk factors in an Iraqi community( 2013)A growing awareness of the epidemiology of molar-incisor hypomineralisation (MIH) highlights the need to investigate the distribution and causes of this defect across a range of communities. Together with establishing the extent of the disorder comes a need to identify the cause and understand how to prevent MIH from occurring in the future. So that appropriate care can be provided to those with existing lesions, a clear picture of clinicians’ current level of knowledge about MIH is fundamental. Little research investigating the distribution of MIH-like opacities in the second primary molar (HSPM), exists. The dynamic properties of enamel hypomineralisation may predispose the affected tooth to deteriorate post-eruptively by developing dental caries in the presence of an unfavourable oral environment and absence of treatment intervention. The influence of salivary characteristics and existing caries experience on the clinical presentation of MIH is unknown. While investigations into the impact of the defect on the individual are lacking, the sequalae of untreated MIH include pain and high treatment costs which add to the public health burden of disease in the community. The present research project had two major aims: (1) to assess the perception of 146 Iraqi dental academics regarding the prevalence, severity and possible aetiological factors of MIH and HSPM (2) to investigate the distribution, risk factors and the impact of these defects on the oral health of 823 schoolchildren. The results indicated that the majority of the Iraqi dental academics (81.2%) encountered MIH in their clinical activities. Fewer than half of the respondents observed MIH affected teeth on a monthly basis. HSPM was less commonly seen than MIH. A variation in views about MIH specific aetiological factor/s was evident. Respondents advocated the need for clinical training regarding MIH-aetiological and therapeutic fields. Analysis of the prevalence and severity of the defect revealed 153 (18.6%) of the children examined had at least one affected first permanent molar (FPM) or FPMs and incisors and were considered as MIH-affected, while 53 (6.6%) had hypomineralisation defects in at least one SPM and were considered as HSPM-affected. Maxillary index teeth had the highest defect prevalence (61.5%). Demarcated creamy white opacities were the most frequent lesion type (48.7%). The severity of defects increased with age and the prevalence was greater in boys compared to girls. The more severe the lesion the greater was the involved tooth surface area. Of those with HSPM, 39.6% were diagnosed with affected FPMs simultaneously, whereas only 7.5% of them reported HSPM with affected incisor but not with affected FPMs. Analysis of the medical history revealed approximately 94% of the children with demarcated lesions had experienced one or more medical conditions compared with 70% of the defect free children. Post-natal health conditions were the most commonly associated health events in the MIH-affected group (33.3%), whereas peri-natal health conditions were the most frequently reported health events for HSPM-affected group (45.3%). When the data were split into the possible risk-effect groups, risk factors contributing to MIH were also identified as risk factors for HSPM. Analysis of the relationship between the defects with caries severity and saliva characteristics illustrated that hypomineralised-affected children have significantly higher mean caries scores compared to the non-affected group. Dentinal carious lesions were ten-times more frequent in teeth with post-eruptive enamel breakdown (PEB) than with teeth with opacities only. Low salivary flow rates (LSFR), moderately viscous saliva and low pH were significantly more common in the affected group. LSFR, moderate-and highly-acidic saliva were more likely to be associated with PEB. Analysis of the potential MIH-impact on oral health burden indicated that MIH-affected children had significantly higher frequency of seeking dental care than their non-affected counterparts (82.4%, 68.2%; respectively). They were over three times (OR 3.2) more likely to visit the dentist complaining of pain and were over six times (OR 6.4) more likely to seek dental care due to tooth sensitivity than their non-affected peers. Affected molars required more than twice the amount of restorative care than unaffected molars. No significant difference was found between the study groups in terms of tooth-brushing and toothpaste-use history, with brushing frequency “once-a-day” commonly reported in both groups (75.5%). Early exposure to fluoridated water appeared to have a protective effect for MIH (OR 0.4).