Evaluation of micro-implant anchorage insertion site and angle in the maxillary posterior region of 34 adult patients with skeletal class Ⅱ:A cone-beam computed tomography study
Objective To provide reference for the selection of implant site by evaluating the thickness of buccal cortical bone and buccolingual bone as well as the interradicular distance of maxillary posterior area in patients with different vertical facial patterns.Methods 34 cases of skeletal class Ⅱ adult patients were divided into three groups according to mandibular plane angle:hyperdivergent,normodivergent and hypodivergent.CBCT was used to measure the interradicular distance of the maxillary second premolar and the first molar at the height of 3 mm,5 mm and 7 mm from the alveolar crest,the thickness of buccal cortical bone and buccolingual bone at the angles of 0°,45° and 60°,respectively.Results The thickness of the buccolingual bone in hyperdivergent group with 0° insertion at the height of 5mm was smaller than that in the hypodivergent group(P＜0.05).The greater the implantation angle made with the alveolar crest,the greater buccal cortical thickness we can get.In addition,the buccal cortical thickness with 0° insertion at 7 mm in three groups was greater than 3 mm with the same insertion(P＜0.05).In three groups,the buccolingual bone with 60° insertion at 7 mm was thinner than 0° at the same height(P＜0.05).What's more,the buccolingual bone at 7 mm was thinner than 3mm with 45° and 60° insertion(P＜0.05).The interradicular distance at the height of 7 mm from the alveolar crest was greater than the height of 3 mm both in the hyperdivergent and normodivergent group(P＜0.05).Conclusion When a skeletal class Ⅱ adult patient choses to insert MIA between the maxillary second premolar and the first molar buccally,it should be inserted at the height of 5 mm from the alveolar crest with 45° angulation on the coronal plane and it is not necessary to pay much attention to the different vertical facial patterns.
NETL
NSTL
万方数据
