Characteristics of dental arch and basal bone in permanent dentition Angle Class Ⅱ malocclusion based on three-dimensional digital models / 中国组织工程研究

ABSTRACT

BACKGROUND:An orthodontist can gain all comprehensive data about the tooth and jaw based on a model measurement.With the development of CAD/CAM,a three-dimensional (3D) digital model shows more accurate information than a traditional model.OBJECTIVE:To explore the characteristics of dental arch and basal bone in permanent dentition Angle Class Ⅱ malocclusion based on 3D digital models.METHODS:Thirty cases of normal occlusionin permanent dentition were selected as control group,and 30 cases of Angel Ⅱ1 and 30 cases of Angel Ⅱ2 malocclusion were enrolled,respectively.Three kinds of 3D digital models were established using a 3shape R700 scanner and measured with Orthoanalyzer 2013.The data of individual normal occlusion and Angel Ⅱ1 and Angel Ⅱ2 data were analyzed statistically with SPSS 19.0 software respectively.Intergroup comparison was analyzed by the least significant difference test method.RESULTS AND CONCLUSION:Maxillary and mandibular dental arch length and maxillary dental arch width of front section (3-3) and middle section (4-4)/maxillary basal bone length and mandibular basal bone width of middle section (4-4)Ⅱ2 ＞ normal occlusion ＞ Ⅱ1 (P ＜ 0.05).Mandibular dental arch front width of section (3-3)/maxillary and mandibular basal bone lengthnormal occlusion ＞ Ⅱ1＞ Ⅱ2 (P ＜ 0.05).Maxillary dental arch width of behind section (6-6)/maxillary basal bone width of front section (3-3) and middle section (4-4)/mandibular basal bone width of front section (3-3)normal occlusion ＞ Ⅱ2 ＞ Ⅱ1 (P ＜ 0.05).The angle of tooth long axis and planethere was significant difference in the Angel Ⅱ1,Ⅱ2 and normal occlusion (P ＜ 0.05).Maxillary posterior-teeth area (coronary)Ⅱ1 ＞ Ⅱ2 ＞ normal occlusion (P ＜ 0.05).Mandibular posterior-teeth area (coronary)Ⅱ2 ＞ normal occlusion ＞ Ⅱ1 (P＜ 0.05).The dental arch of Angel Ⅱ1 was narrow and long in shpape,and the dental arch of Angel Ⅱ2 was wide and short in shape.Sagittal discordant existed in the anterior of Angel Ⅱ1,such as lip-side incline of maxilla and mandible.Coronal discordant existed in the median and posteior of Angel Ⅱ1,such as palatine-side incline of the maxillary dental arch,and buccal-side incline of the mandible.Sagittal discordant existed in the anterior of Angel Ⅱ2,e.g.lingual-side incline of the maxilla and mandible.No discordant existed in the posterior section of Angel Ⅱ2.