Ultrastructural analysis of the teeth affected by amelogenesis imperfecta resulting from FAM83H mutations and review of the literature.

OBJECTIVE

To analyze the ultrastructure and chemical compositions of two teeth affected by amelogenesis imperfecta (AI) with specific FAM83H mutations.

STUDY

DESIGN

Mutation analysis was performed by sequencing the candidate FAM83H gene. Two extracted teeth were collected: one from a new family and the other from a previously reported family with FAM83H mutation (Q452X). The specimens were prepared for ultrastructure detection using scanning electron microscopy (SEM) and elemental analysis by energy dispersive X-ray spectrometry (EDX).

RESULTS

An FAM83H mutation R325X was identified in the new family. In the two specimens, the affected enamel showed irregular, broken, and collapsing enamel rods with decreased numbers and widened interrod spaces; the affected dentine exhibited thickened peritubular dentine and irregular, narrowed, or partially obliterated dentinal tubules. EDX analysis showed the affected enamel with a higher carbon content, nitrogen content, and carbon/oxygen ratio.

CONCLUSION

Our study demonstrates that FAM83H mutations could influence enamel biomineralization and dentine formation.