Unilateral molar Incisor hypomineralization influences the chewing side? an observational study in children

Objective: The aim of this observational study was to compare the chewing patterns of children with unilateral Molar Incisor Hypomineralization (MIH) to those of children without MIH and to assess how the MIH severity influences the risk of chewing deviation. The hypothesis was that children with unilateral MIH would prefer to chew on the side opposite the defect.

Methods: A total of 121 children were included in this investigation and evaluated for their preferred chewing side (PCS). This study population comprised 45 children with unilateral mild MIH (G1), 42 with unilateral severe MIH (G2), and 34 children in the control group (CG) who had no MIH but presented with unilateral chewing complaints.

Results: The PCS pattern differed among the groups, with 31% of the children with MIH and 55.9% of the CG showing bilateral chewing. The chewing deviation prevalence was 24% in the CG and 52% in G2 (χ2 test; p = 0.03). Binomial logistic regression analysis revealed that both severities of MIH influenced the likelihood of chewing deviation (χ2 = 7.33, p = 0.026). Children with unilateral severe MIH were 3.57 times more likely to exhibit chewing deviation than were those without MIH.

Conclusions: The null hypothesis was rejected, indicating that unilateral MIH affects children's masticatory patterns, increasing the risk of chewing deviation.

Clinical relevance: Unilateral chewing may be associated with various health issues, such as temporomandibular disorders (TMDs), decreased hearing, and vision problems. Unilateral MIH is a potential risk factor for unilateral chewing.