【摘要】 目的调查黑龙江地区恒牙列早期第二恒磨牙各种错畸形的发病率情况及分布规律。方法随机抽取13~15岁中学生3 600人进行调查。结果在3 600个样本中,1 854个存在第二磨牙错畸形,发病率为51.50%,其中男性占52.27%,女性占47.73%。上颌第二磨牙错颊向错位比率最高,占52.96%。下颌则以舌向错位比率高,占53.01%。在第二磨牙错畸形中,安氏Ⅰ类、Ⅱ类和Ⅲ类所占比率依次为48.76%、26.54%和24.70%,第一磨牙咬合关系为反的发病率占2.75%。结论在恒牙列初期第二磨牙错畸形的发病率很高,并且在调查中屡次出现第一磨牙关系为反,影响青少年的颌骨的生长发育,应该引起患者及医生的重视。更多还原

【Abstract】 OBJECTIVE To investigate the prevalence rate and the distribution of the second molar malocclusion in early permanentdentition in the area of Heilongjiang. METHODS Taking the method of cluster sampling to extract 3 600 middle school students fromthe age of 13 to 15 years old and making the survey. RESULTS The prevalence of the second molar malocclusion among the earlypermanent dentition in the area of Heilongjiang was 51.5%,which accounted for 52.27% of men,women accounted for 47.73%,The buccal dislocation rate is the highest in the maxillary second molar malocclusion,which is 52.96%. While lingual dislocationrate was also the highest in the mandibular second molar,reaching to 53.01%. The second molar malocclusion in students with angleClassⅠ,class Ⅱ,class Ⅲ accounted for were 48.76%,26.54% and 24.70%,the rate of cross bite was 2.75% in the first molar oc-clusion. CONCLUSION The prevalence rate of the second molar malocclusion was very high in early permanent dentition,and inthe investigation,it found the first molar occlusion appears to be crossed bite in the cases.Above these situations will effect thegrowth and development of the youngsters’ jaw. Doctors and patients should pay attention to these.更多还原