Prevalence and causes of Developmental defects of enamel

Developmental defects of enamel (DDE) may be caused by genetic, systemic or local factors during the enamel maturation. Objectives: The aim of this study was the registration of the prevalence of DDE in first permanent molars and incisors in the city of Jena (Germany) as well as the verification of possible causes. Methods: 945 children aged 6-12 years were examined using a modified DDE-Index. The teeth were not dried prior to the examination and a LED-light was used. Results: Teeth with defective enamel were seen in 40.7% of the children, while 33.1% were observed in at least two teeth. 29.6% was presented in first molars of which 23.4% in two or more. Demarcated opacities (MIH) were diagnosed in 27%, diffuse opacities in 21.1% and hypoplasias in 2.4% of the children (in molars 18.4% / 13.7% / 1.2%). MIH and hypoplasias occur mostly in one tooth (9.5% resp. 1.3%), opposite diffuse opacities were found mainly in two (6.1%). Preferred teeth of demarcated opacities were the molars (9.9%), of diffuse opacities the upper middle incisors (12.8%) and of hypoplasias the upper second incisors (1.1%). The highest fragility concerning caries was seen in children with hypoplasias (DMF-T=0.64) followed by children with MIH (0.64), without DDE (0.33) and diffuse opacities (0.30). Possible causes of the disorders in enamel formation, occurred in the first year of life, were examined on the basis of a parent questionnaire and showed the following significant results. MIH showed an association to urinary-tract-infections and pyelitis, hereditary-nephrotic-diseases and hypothyroidism while medicating with L-Thyroxin, breech-presentation during pregnancy and to forceps-births. An association between diffuse opacities and hereditary-nephrotic-diseases as well as the intake of analgesics was recorded. Children with hypoplasias showed 16 times more epilepsy. Conclusions: The etiology of teeth with DDE is related to health problems in infancy, especially to nephrotic diseases.