Aim of the Study Evaluate association between HSPM and MIH in Egyptian children. Record the prevalence of HSPM and MIH in Egyptian children

Statement of the Problem:

Molar Incisor Hypomineralization (MIH) is defined as developmental qualitative defect of systemic origin, which affects one to four of first permanent molars and frequently associated with permanent incisors . The prevalence of MIH worldwide was reported from 2.4% to40.2% and clinical measures of MIH based on scientific criteria was established based on the European Academy of Pediatric Dentistry criteria to allow comparison between the findings of different studies .

The most commonly reported clinical problems for patients with MIH are hypersensitivity of teeth to various thermal and mechanical stimuli result in improper tooth brushing, plaque accumulation and rapid caries progression. Severely affected enamel shows post eruptive breakdown and such teeth require extensive treatment, ranging from prevention to restorations and extractions. MIH patients also have increased risk of developing dental fear and anxiety as well as behavior management problems added to the difficulty to achieve effective local anaesthesia which are related to chronic pulp inflammation from dentin exposure due to excessive enamel breakdown.

Rational As developmental of Second Primary Molar start at the same time as the development of the first permanent molars and incisor but the maturation of permanent teeth occur more slow. So when a systemic disturbance occur it affect second primary molar as well as first permanent molar and incisors.

Few studies test the association between hypomineralized second primary molar (HSPM) and MIH. While no study available on Egyptian children.

Inclusion Criteria:

• Children aged from 8 to 9 years.
• Both genders.
• No systemic health problems

Exclusion Criteria:

• Children with extracted primary second molars and permanent incisors and molars.
• Children with history of dental trauma.
• Children with orthodontic bands or dental appliances

Healthy children aged from 8 to 9 years attending outpatient clinic in Pediatric Dentistry Department, Faculty of Dentistry, Cairo University will be included in this study according to eligibility criteria