Factors related to spontaneous space closure following early first permanent molar extraction: A systematic review

Background: Dental caries and molar–incisor hypomineralization (MIH) are primary reasons for the extraction of first permanent molars (M1) in children, which can lead to significant dental and facial development issues such as a midline shift and temporomandibular joint disorder. Aim: This systematic review aimed to identify key factors influencing spontaneous space closure following the early extraction of first permanent molars (M1) in children aged 5–15. Design: We conducted a comprehensive search across Scopus, PubMed, Dimensions, Web of Science, and Cochrane databases, including the literature from 1960 to 2024. The inclusion criteria focused on clinical trials, case–control, cross-sectional, cohort studies, and case series that evaluated the impact of various factors on the spontaneous closure after M1 extraction. Results: The analysis highlights that chronological age and the developmental stage of the second permanent molars (M2) at the time of extraction are significant predictors of successful spontaneous space closure. Additionally, the presence and angle of M2, along with the presence of third permanent molars (M3), play crucial roles but require further investigation. Conclusion: Early assessment of M2's developmental stage and inclination, and the presence of M3 are essential for enhancing the likelihood of successful spontaneous space closure following M1 extraction in children.