Lenaker, Dane2022-09-132022-09-132022-05https://hdl.handle.net/11299/241547University of Minnesota M.S. thesis. 2022. Major: Dentistry. Advisor: Thorsten Grünheid. 1 computer file (PDF); 78 pages.Aim: To evaluate first permanent molar (FPM) replacements by assessing complete radiographic space closure between the second permanent molar (SPM) and the second premolar. To evaluate the supereruption in compensated and uncompensated maxillary molars in patients with mandibular FPMs extractions. To determine if the odds of complete space closure by second permanent molar (SPM) replacements is influenced by compensating extraction. To validate a tool kit to predict the likelihood of spontaneous space closure after the loss of FPM in the Yup'ik population. Methods: One hundred and thirty-four patients aged six to thirteen years with extracted FPM(s) were evaluated for space closure between the mandibular second molar and the second pre-molar at follow-up. Initial panoramic radiographs were reviewed for the presence of a third permanent molar (TPM), along with the SPM angulation. Bitewing radiographs of one hundred and fifty-six patients aged six to thirteen years with previous FPM extraction were used to evaluate linear measures of supereruption in compensated and uncompensated extractions. Patients with both FPM extractions and compensated and uncompensated extractions were evaluated for complete mandibular space closure. Results: The confidence intervals of five of the six space closure categories contained values found within the tool kit. Multivariate logistic regression demonstrated that extraction at age 8 to 10 vs. 11 to 12 (p=0.04; OR = 0.29, 95% CI 0.08 – 0.91), TPM presence (p=0.02; OR = 2.35, 95% CI 1.16 – 4.9), and follow-up time were statistically significant predictors of space closure. A second model demonstrated that odds of uncompensated FPM supereruption is greater than that of compensated FPMs (p=0.0001; OR = 3.55, 95% CI 1.86 – 6.92) and that additional follow-up increases the odds of supereruption (p=0.0005; OR = 1.18, 95% CI 1.08 – 1.30). A final model demonstrated that uncompensated extractions did not reduce the odds of spontaneous space closure (p=0.54; OR=1.3, 95% CI 0.56 – 3.08). Conclusion: FPM extraction later than 10 years of age appears to be a negative predictor for space closure, while TPM presence is a positive predictor. Uncompensated maxillary FPMs do not appear to inhibit mandibular SPM space closure; however, uncompensated extractions are more likely to supererupt than compensated extractions. Length of follow-up is a critical factor for assessing both space closure and supereruption. Additional research is required to make generalizable conclusions about the validity of the tool kit studied.enCOMPENSATING EXTRACTIONEXTRACTION TIMING AND SUPERERUPTIONMOLAR HYPOMINERALIZATIONPERMANENT FIRST MOLAR EXTRACTIONSECOND MOLAR SUBSTITUTIONSPONTANEOUS SPACE CLOSUREThesis or Dissertation