Hypomineralisation of second primary molars and primary canines: Prevalence and description of lesions in a population of 153 patients visited at a hospital paediatric dentistry service.

Aim: The enamel defects of Molar-Incisor Hypomineralisation (MIH) share clinical characteristics with hypomineralised second primary molars (HSPM) and hypomineralised primary canines (HPC). The main objective of this study is to determine the prevalence of these entities in a population of patients in a hospital dentistry service. The secondary objectives are to know the number and distribution of lesions, classify them according to their degree of severity and to know which dental surfaces are most affected.

Methods: A cross-sectional and observational prevalence study was carried out over a 32-day period, guided by the diagnostic criteria of the European Academy of Paediatric Dentistry (EAPD) together with the descriptive study of the lesions. Healthy patients between 30-42 months and who had all erupted teeth were included.

Results: Out of a total of 153 patients, 29 presented HSPM (18.95%) and 17 HPC (11.11%). Check-ups were made on 116 second primary molars (SPM) and 116 primary canines (PC), obtaining 81 HSPM (69.82%) and 31 HPC (26.72%). The lesions observed were mild in 60 molars (74.07%) and in 27 canines (87.09%). As for the 405 surfaces checked, 168 showed HSPM (41.48%) and 43 HPC (10.61%).

Conclusions: The prevalence of HSPM and HPC varies depending on the population studied. It was observed that SPM were affected more often than PC, with the occlusal and buccal surfaces being the most affected, and the majority of the lesions presenting a low degree of severity.