Effects of Micro-implant Anchorage Correction on Soft Tissue Profile and Nasolabial Chin Coordination in Patients with Bimaxillary Protrusion
Objective To explore the effects of micro-implant anchorage correction on soft tissue profile and nasolabial chin coordination in patients with bimaxillary protrusion.Methods A retrospective analysis was performed on the clinical data of 60 patients with bimaxillary protrusion in the hospital between April 2017 and November 2020,including 30 cases given traditional extraoral reinforcement anchorage in group B and 31 cases given microscrew implant anchorage in group A.The correction time,cephalometric measurement items and changes of periodontal inflammatory microenvironment in the two groups were compared.Results The turn-off time of extraction space and correction time in group A were shorter than those in group B(P<0.05).After treatment,angle of U1-Ll in group A was greater than that in group B,while angle of U1-NA was smaller than that in group B(P<0.05).After treatment,protruding distance of upper and lower lip(UL-E line and LL-E line)in group A was longer than that in group B(P<0.05).After treatment,depth of mentolabial sulcus,nasolabial angle and inclination of chin sulcus in group A were greater than those in group B(P<0.05).At 6 months after treatment,sulcus bleeding index,gingival index and plaque index in group A were lower than those in group B(P<0.05),and levels of interleukin-6(IL-6),matrix metalloproteinase-2/-9 and tumor necrosis factor-α in periodontal tissues were lower than those in group B(P<0.05).Conclusion Microscrew implant anchorage has obvious orthodontic effect on bimaxillary protrusion.Compared with traditional extraoral reinforcement anchorage,it has more consistent facial profile with aesthetic standards and less stimulation to periodontal environment,which can shorten correction time to a certain extent.