Effect of flapless osteoperforation-assisted tooth movement on atrophic alveolar ridge: Histomorphometric and gene-enrichment analysis

Objective: To investigate the effect of flapless osteoperforation on the tissue response of the atrophic alveolar ridge affected by orthodontic tooth movement (OTM). Materials and Methods: An atrophic alveolar ridge model was established in the mandibular quadrants of eight beagle dogs. As a split-mouth design, the quadrants were randomly divided into group C (OTM only) and group OP (OTM with flapless osteoperforation). The rate of OTM for 10 weeks was compared between groups, and micro-CT-based histomorphometric analysis and RNA-sequencing-based gene-enrichment analysis were performed targeting the atrophic ridge. Results: Group OP displayed more rapid tooth movement with lower bone mineral density and higher trabecular fraction in the atrophic ridge than did group C, showing no intergroup difference of total ridge volume. As contributing biological functional pathways in group OP, the genes related to osteoclast differentiation and TNF signaling pathway were up-regulated and those associated with Wnt signaling pathway and AMPK signaling pathway were down-regulated. Conclusions: Flapless osteoperforation facilitated the rate of OTM toward the atrophic ridge, maintaining low bone density, whereas it did not increase the volume of the atrophic ridge.