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Updated: Jun 9, 2025
The Establishment of a Murine Mandibular Molar Extraction Socket Healing Model
Published on: January 13, 2023
Spontaneous space closure after extraction of young first permanent molar. Retrospective cohort study
Heba Jafar Sabbagh1, Ahmad Adnan Samara2, Shoroog Hassan Agou3
1Pediatric Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
Background:
Early compromised first-permanent-molar (FPM) extraction can adversely affect occlusion. However, the current literature does not provide sufficient support for definitive early extraction outcome. This cohort study aimed to evaluate the pattern of post-FPM extraction spontaneous space closure and its pre-extraction indicators.
Methods:
Patients of 7-13 years, with compromised FPM at three-tertiary-centers between 2015 and 2019 were retrospectively screened. Pre-extraction indicators were evaluated (extraction location, direction of the second permanent molar (SPM) long-axis, and SPM Demirjian development stage). Spontaneous space closure pattern was evaluated clinically and radiographically using the American Board of Orthodontics (ABO) grading system.
Results:
In total, 112 FPMs (73-patients) were identified and five (4.5%) of the extraction sites showed favorable combined-ABO-scores. Distal direction of the SPM long-axis in the maxillary arch significantly decreased the relative risk (RR) of having a SPM rotation/alignment ABO score-1 (P = 0.002; RR = 0.64). For the mandibular arch, Demirjian stage D and E significantly decreased the RR of having ABO score-1 for spacing between the SPMs and second premolars (P = 0.029; RR:0.57, P = 0.004; RR:0.53, respectively) and vertical dimension (P = 0.02; RR = 0.53).
Conclusions:
The direction of the SPM long-axis and its developmental stage are key indicators of the favorable outcome pattern of spontaneous space closure after FPM early extraction.
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