青少年恒磨牙发育情况回顾性分析对指导正畸治疗的研究

发布时间：2018-10-08 18:26

【摘要】：目的全颌曲面断层片能观察全口牙列以及上下颌骨的发育情况,更适合观察研究牙齿的生长发育;临床上常常利用全景片来研究磨牙的萌出情况,结合计算机技术形成的数字全景片,能将磨牙的真实情况更精确地显示。通过分析11-14岁青少年恒磨牙(主要是第二磨牙M2和第三磨牙M3)的影像学表现,研究恒磨牙的发育、萌出情况,以及M3、M2的发育关系。方法从常州市口腔医院影像资料中抽取2013年1-10月期间拍摄的全颌曲面断层片,样本纳入标准为:①年龄为11-14岁的青少年;②图像清晰度好,下颌骨无明显变形、扭曲;③无M3的拔除史;④X片显示无先天缺牙以及牙本质发育不全等;⑤未做过正畸治疗;⑥单颌牙弓拥挤不超过2mm,无过大牙、过小牙、下沉牙、异位牙、多生牙等,男性150例,女性195例,共345张。研究分析第二、三磨牙的牙齿生长状况、牙根发育状态、发育差异等并进行发育分期;第三磨牙萌出位置、与第二磨牙的间距并分析两者的相关性,初步预测分析第三磨牙阻生及拔除的可能和第一、二磨牙的龋患及阻生情况。结果在11-14岁青少年中,M2处于发育G期的比例为43.26%,下颌整体发育早于上颌(Z=-11.685,P值0.000,P0.05);女性明显较男性发育早(Z=-3.058,P值0.002,P0.05);不同年龄的发育阶段有显著性差异(c2=425.427,P值0.001)。21颗阻生,均为下颌近中倾斜,占已萌出下颌M2总数的3.83%。M3处于发育C期的比例为33.26%,女性比男性发育早(Z=-2.056,P值0.040,P0.05);下颌M3发育早于上颌(Z=-3.419,P值0.001,P0.05);不同年龄的发育阶段有显著性差异(c2=501.301,P值0.001)。M3与M2计算Spearman相关系数是0.869,P0.001,差异有统计学意义,说明二者存在相关性。M1的龋坏率为0.72%。已萌出的下颌M2近中阻生组的下颌第二磨牙倾角(Am2-m1)大于萌出组,有显著性差异(P0.05);萌出组的女性下颌第二磨牙倾角小于男性,有显著差异(P0.05)。结论11-14岁的青少年M2的发育阶段大部分位于G阶段,是进行牙齿矫治的最佳有利时期。该阶段需要重视下颌M2牙倾角的变化,防止近中阻生;已有倾向者需要及时干预。女性的M2和M3发育均明显较男性早。M2和M3的生长趋势具有一致性,经Spearman相关分析,两者发育存在相关性,可以为分析恒牙牙合早期后段牙弓状况提供参考,对于错牙合畸形的预测和矫治计划的制定具有重要的临床意义。
[Abstract]:Objective to observe the development of total dentition and upper and mandible, and to study the growth and development of teeth, panoramic films are often used to study the eruption of molars in clinic. Combined with computer technology, the digital panorama can show the real situation of molars more accurately. By analyzing the imaging features of permanent molars (M2 and M3) of 11-14 years old, the development, eruption and developmental relationship of M3M 2 were studied. Methods Total maxillary surface tomograms were taken from the imaging data of Changzhou Stomatological Hospital from January to October 2013. The inclusion criteria of the images were: 1: 1 the young people aged 11 to 14 years old had good definition of images, the mandible had no obvious deformation and distortion. (3) the extraction history without M3 and 4X film showed that no congenital tooth defects and dentin dysplasia etc. 5. No orthodontic treatment, no more than 2mm crowding of single maxillary arch, no large teeth, small teeth, sinking teeth, ectopic teeth, supernumerary teeth, etc., male 150 cases, male 150 cases. There were 195 women (345). The second and third molars were analyzed for tooth growth, root development, developmental differences and developmental stages, and the location of the eruption of the third molar and the distance between the second molar and the second molar were analyzed and the correlation between the two was analyzed. The possibility of impaction and extraction of the third molar and the caries of the first and second molars were preliminarily predicted and analyzed. Results the proportion of M _ 2 in G stage was 43.26, the whole mandibular development was earlier than that of the upper jaw (P = 0.000P05), the development of female was earlier than that of male (P = 0.002P), there was significant difference between different ages (C _ 2o _ 425.427P = 0.001). All of them were proximal and middle mandibular oblique. The proportion of 3.83%.M3 in developing C stage was 33.26%, the development of M3 in female was earlier than that in male (P = 0.040 P), the development of M3 in mandible was earlier than that in maxilla (P 0.05), there was significant difference in developmental stage of different age (C2501.301 P value 0.001). M3 was associated with M 2 calculation of Spearman. The coefficient was 0.869m (P 0.001), the difference was statistically significant. The caries rate of M1 was 0.72%. The mandibular second molar obliquity (Am2-m1) of the newly erupted M2 group was higher than that of the eruption group (P0.05), and the female mandibular second molar obliquity angle of the eruption group was lower than that of the male (P0.05). Conclusion the developmental stage of M 2 in 11-14 years old adolescents is mostly in G stage, which is the best favorable period for dental correction. In this stage, attention should be paid to the change of mandibular M2 obliquity to prevent proximal and middle impaction, and those who have tendency need to intervene in time. The growth trend of M2 and M3 in females was significantly consistent with that in males. By Spearman correlation analysis, there was a correlation between the development of M2 and M3, which could be used as a reference for the analysis of posterior arch in early permanent teeth. It has important clinical significance for the prediction of malocclusion and the establishment of correction plan.
【学位授予单位】：安徽医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R783.5

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