Concentration of MMP20 and KLK4 during enamel development in MIH

Zilberman U, Shama A, Amara R and Hassan J

Published on: 2023-07-10

Abstract

Objectives:

To determine the concentration of matrix of metalloproteinase 20 (MMP20) and kallikrein 4 (KLK4) during the maturation stage of amelogenesis on MIH/SPMH development. During the secretory stage of amelogenesis the ameloblasts start secreting large amounts of enamel matrix proteins.  The enamel proteins are removed during the maturation stage by two proteases: MMP20 and KLK4.

Design:

During 2018, concentration of MMP20 and KLK4 were determined from blood samples of 500 children aged 0-5 years old. Four years latter a sample of 89 children (aged 6-7 years) were clinically examined for MIH/SPMH signs on their permanent or deciduous molars by trained residents, according to EAPD criteria.

Results:

25 children showed signs of MIH/SPMH out of 89. The concentration of MMP20 and KLK4 were statistically analized in the children with MIH/SPMH in comparison with children without. In children with clinical signs of MIH/SPMH the concentrations of of KLK4 was significantly lower (4.99 in comparison with 7.84 in control group; P value=0.02). The concentration of MMP20 was higher in the MIH/SPMH group but without statistical significance (P value=0.24).

Conclusions:

KLK4 is expressed during the transitional and maturation stages and is responsible for protein degradation. In the absence of KLK4 substantial retention of enamel proteins occurs in the enamel. It may be postulated that the retention of enamel proteins in MIH/SPMH teeth was caused by reduced concentration of KLK4 during transitional and maturation stages of amelogenesis.