title: Severity of MIH findings at tooth surface level among German school children.
abstract: OBJECTIVE
  This study was to investigate the distribution and clinical characteristics of teeth diagnosed with MIH at surface and defect type level in a cohort of German children.
  
  
  METHODS
  The study cohort included 242 children diagnosed with MIH which had been recorded during the compulsory dental school examinations of 20 German primary schools. The subjects had been enrolled by cluster sampling. All children attended the second to fourth grade (age 7-10 years, mean 8.1 ± 0.8). The children were examined by five calibrated examiners (kappa = 0.9) after tooth brushing. The recording comprised teeth, surfaces, type and severity of MIH defects and was conducted using a portable light, mirrors and cotton rolls. MIH was registered according to the EAPD criteria. Defects <1 mm were not recorded. Statistical analysis included descriptive statistics and Spearman's correlation.
  
  
  RESULTS
  Most affected teeth were first permanent molars (71.4 %) followed by the maxillary central incisors (15.6 %). The most common defects were demarcated opacities (82.2 %), while the remaining 17.8 % of the affected teeth exhibited severe enamel defects. The most frequently affected surface in molars was the occlusal surface (72.4 %); in incisors, it was the buccal surface (73.5 %). There were no atypical restorations in the affected incisors. Different types of MIH defects at various surfaces of the same tooth were common. The number of affected tooth surfaces was positively correlated with the severity of MIH at child (p < 0.001).
  
  
  CONCLUSIONS
  The study demonstrates severe enamel defects involving in almost one-fifth of all MIH teeth. The knowledge of the intra-oral distribution and severity of MIH findings at the enamel surface level is important for assessing the treatment needs.
authors: Department of Preventive and Paediatric Dentistry, University of Greifswald, Greifswald, Germany, mpetrou@ukaachen.de.
authors: M A
authors: MA
authors: Petrou
authors: M
authors: M
authors: Giraki
authors: A-R
authors: AR
authors: Bissar
authors: C
authors: C
authors: Wempe
authors: M
authors: M
authors: Schäfer
authors: U
authors: U
authors: Schiffner
authors: T
authors: T
authors: Beikler
authors: A G
authors: AG
authors: Schulte
authors: C H
authors: CH
authors: Splieth
mesh_terms: D002648:Child; D015331:Cohort Studies; D003743:Dental Enamel / Q000002:abnormalities; D003744:Dental Enamel Hypoplasia / Q000145:classification* / Q000473:pathology; D005260:Female; D005858:Germany; D006801:Humans; D007180:Incisor / Q000002:abnormalities; D008297:Male; D008963:Molar / Q000002:abnormalities; D019228:Tooth Crown / Q000002:abnormalities