Molar incisor hypomineralisation: prevalence in Jordanian children and clinical characteristics

To investigate Molar Incisor Hypomineralisation (MIH) in Jordanian children in terms of prevalence, distribution and severity of defects.

A crosssectional national study with a representative sample was used. A multistage random sampling system yielded 3,666, 7-9 year-old schoolchildren, from 97 public, private and UNRWA schools from Amman, Irbid and Al-Karak. A questionnaire of six sections was sent to the parents with a consent form to participate in the study. A total of 3,241 children participated resulting in a response rate of 88.4%. A single calibrated investigator examined all children using established criteria for MIH and molar hypomineralisation (MH). Analysis of data was performed with a p value set at 0.05.

Of the children examined, 570 (17.6%) were diagnosed with MIH with more females affected than males (53% vs. 47%). The 570 subjects were distributed as MIH cases in 196 children (34.4%) and MH cases in 374 children (65.6%) given that at least one incisor was erupted. Mandibular molars and maxillary central incisors were more frequently affected (p<0.05). No significant difference was found between right and left sides of the mouth. Most defects were mild in severity (44%) and severity increased with age and was related to the number of teeth affected (p<0.05). MIH teeth were more severely affected than MH teeth.

MIH was common among 7-9 year-old Jordanian children with a prevalence of 17.6% and was gender related. MH was more common than MIH and can be considered a mild form of an MIH spectrum. Majority of MIH and MH cases were mild in nature but demonstrated an agerelated severity.