بررسي شيوع و عوامل پيش بيني كننده وقوع هيپومينراليزاسيون مولر-ثنايا در شهر رشت

An Investigation of the Prevalence and Predictive Factors of Molar-Incisor Hypomineralization in Rasht, Iran

مقدمه: هدف از انجام اين مطالعه بررسي شيوع هيپومينراليزاسيون مولر انسيزور (MIH) در كودكان 13-6 ساله شهر رشت و عوامل پيش بيني كننده آن بود. مواد و روش ها: شركت كنندگان در اين مطالعه، 1043 كودك از دبستان هاي دولتي و غيردولتي رشت بودند. فراواني MIH براساس معاينه باليني تعيين گرديد و سپس 235 كودك مبتلا به MIH و گروه شاهد آنان جهت تعيين عوامل احتمالي ايجادكننده مورد ارزيابي قرار گرفتند. براي جمع آوري اطلاعات از مصاحبه و پرسشنامه شامل سوالاتي درباره مشكلات اواخر دوران بارداري، هنگام تولد و بيماري هاي سه سال اول زندگي، استفاده شد. براي بررسي رابطه بين عوامل مختلف از آزمون هاي كاي دو، آزمون دقيق فيشر، من- ويتني و آزمون تي، استفاده شد (a=0/05). يافته ها: شيوع MIH 19/9 درصد و درگيري مولر به تنهايي 17/46 درصد بود. هركودك به طور متوسط داراي 2/18 دندان داراي ضايعه، شامل 1/9 مولر و 0/28 ثنايا بود. تفاوت معني داري از نظر شيوع و شدت ضايعات در دو جنس ديده نشد (p=0/54و 0/36=X2)، همچنين بين دانش آموزان مدارس خصوصي و دولتي تفاوت معني داري از نظر شيوع مشاهده نشد (47/0=X2 و 58/0P=). مولر هاي پايين بيشتر از بالا دچار نواقص مينايي بودند (19/6= X2وp<0/001). بيشترين فراواني ضايعات مربوط به لكه هاي اوپك بود. هيچيك از عوامل مورد بررسي با MIH رابطه معني داري نداشتند. نتيجه گيري:براساس يافته هاي اين مطالعه، شيوعMIH در شهر رشت از ميزان بالايي برخوردار بود ولي بيشتر ضايعات از نوع خفيف و ميانگين تعداد دندان هاي مبتلا در هر فرد، حدود دو دندان بود. بررسي ارتباط دقيق تر با علل اتيولوژيك از جمله عوامل ژنتيك توصيه مي شوند.

Introduction: Molar-incisor hypomineralization (MIH) is a rapidly destructive type of enamel defects of systemic origin. The aim of the present study was to investigate the prevalence of MIH and the potential predictive factors among the children within the age group of 6-13 years in Rasht, Iran. Materials & Methods: The prevalence of MIH was determined through clinical examination of 1043 children aged 6-13 years. At In the next stage, 235 subjects with MIH and their matched controls were evaluated for determining the probable etiologic risk factors. The data were collected using questionnaire and interviews entailing some questions about the late pregnancy problems, birth time problems, and the diseases at the first three years of life. The data analysis was performed using the Chi-square, Fisher’s exact, and Mann-Whitney U tests through the SPSS version 17. The p-vale less than 0.05 was considered statistically significant. Results: According to the results of the study, the prevalence of MIH was 19.9%, and the sole molar involvement was 17.4%. On average, every child had 2.18 hypomineralized teeth involving 1.9 molars and 0.28 incisor. There was no significant difference between the two genders in terms of the prevalence and intensity of the MIH (P=0.54, X2=0.36). Furthermore, no significant difference was observed between the private and public school students regarding the prevalence of this defect (P=0.51, X2=0.47). As the results indicated, the enamel defects were more common in the lower molars, compared to those in the upper ones (P<0.001, X2=19.6). The most common type of defect was opacities. Moreover, no association was found between the MIH and the investigated variables. Conclusion: As the findings of the present study revealed, the MIH had a high prevalence. However, most of the defects were mild, and the mean of the MIH-affected teeth was two teeth per child. The opacities were the main type of defect. None of the investigated variables was associated with the MIH. Further studies are recommended to investigate the etiologic factors including the genetic background to determine the predisposing factors.