An evaluation of infrazygomatic crest bone thickness in adolescents at different eruption stages of the maxillary second molar detected by cone beam CT
10.3969/j.issn.1672-8467.2024.04.017
- VernacularTitle:锥形束CT测量不同上颌第二磨牙萌出阶段的青少年颧牙槽嵴区骨厚度
- Author:
Ying-Dan PAN
1
;
Zhang-Long ZHENG
;
Wei BI
Author Information
1. 复旦大学附属中山医院厦门医院口腔科 厦门 361015
- Keywords:
cone beam CT;
infrazygomatic crest(IZC);
maxillary second molar;
eruption stage;
bone thickness
- From:
Fudan University Journal of Medical Sciences
2024;51(4):580-587
- CountryChina
- Language:Chinese
-
Abstract:
Objective To explore the distribution and difference of bone thickness in the infrazygomatic crest(IZC)in adolescents at different eruption stages of the maxillary second molar and provide guidance for placement of orthodontic IZC miniscrew.Methods Cone beam CT scans of 110 adolescents with normal occlusion were assessed.According to the eruption stage of the maxillary second molar,the subjects were divided into 3 groups of S1(44 cases),S2(30 cases),and S3(36 cases).The horizontal base plane(HB)in this study was defined as a horizontal axial section with the mesiobuccal cusps of the left maxillary first molar on.Two coronal slices of interest were selected which passing through the apex of mesiobuccal(MB)and distobuccal(DB)roots of the left maxillary first molar respectively.In both of the two coronal slices,the buccal bone thickness was measured at 13(HB13),15(HB15),17(HB17)mm above the HB plane at a gingival inclination of 60°.The measurement differences of bone thickness between MB and DB,and among different heights were evaluated,and the differences among S1,S2,and S3 groups in each simulated paths were compared.Distributions of measurements were reported as colormaps.Results The IZC bone thickness of DB was thicker than MB at HB13 and HB15 in the 3 groups.The higher the insertion height,the smaller the bone thickness(P<0.05).Bone thickness decreased from S1 to S2 to S3 at HB13 and HB15.The maximum bone thickness(5.20 mm)was observed at HB13 in DB,and the minimum bone thicness(1.90 mm)was observed at HB17 in DB.Conclusion The thickest bone in IZC of the three groups located at HB13 in DB of the maxillary first molar,and the bone thickness decreases with the increase of the insertion height.The later the eruption stage of the maxillary second molar,the less bone thickness in the IZC region and the operation difficulty might increase.
