Advantages of implantology-related preventive infra-occluded primary teeth extraction in cases of underlying agenesis: a retrospective study of 290 patients

This study aimed to evaluate the impact of preventive infra-occluded primary teeth extraction in patients with dental agenesis on the success of pre-implantation and implantation treatment, and the preservation of alveolar ridge height.This retrospective analysis included 290 patients with dental agenesis treated at Lille University Hospital between December 2019 and January 2024, including 92 patients with infra-occluded primary teeth. Clinical and radiographic data were collected, and the implant outcomes were compared between those who underwent preventive versus delayed extractions.Preventive extraction was associated with 100% preservation of alveolar ridge height and eliminated the need for vertical bone grafting. In contrast, 28% of patients with delayed extractions experienced vertical bone loss and implant infraposition despite complex grafting procedures. The second primary molars were the most frequently infra-occluded (66.5%), mostly at a moderate degree. The median ages at diagnosis, extraction, and implantation were 14, 17, and 18 years, respectively.Compared to delayed extraction, preventive extraction of infra-occluded teeth in agenesis cases facilitates better implant positioning and reduces the need for complex pre-implant surgeries. Timely intervention is key, particularly in the maxilla, to avoid vertical bone loss and implant complications.