下颌第三磨牙牙胚拔除对正畸治疗患者下颌骨发育影响的研究

Effect of mandibular third molar tooth germ extraction on mandibular development:a retrospective study

目的研究下颌第三磨牙(M3)牙胚拔除术对正畸患者下颌骨发育的影响,以期为临床开展M3牙胚拔除术提供参考。方法纳入2013年1月1日至2021年12月30日就诊于武汉大学口腔医(学)院口腔正畸一科,符合纳排标准的10~16岁安氏Ⅰ类错畸形患者129例,于武汉大学口腔医(学)院口腔颌面外科未拔除M3者纳入对照组(共63例);拔除M3者纳入研究组(66例)。对正畸治疗前后头影测量片进行描点测量下颌支高度(Ar-Go′)、下颌体长度(Go′-Me)及下颌骨整体长度(Co-Gn)并计算3项指标的年均生长量。分别对总体样本患者、同一性别(男/女)患者、同一年龄段(>10岁且≤12岁、>12岁且≤14岁、>14岁且≤16岁)患者、同一颈椎成熟度分期(Ⅱ、Ⅲ、Ⅳ期)患者,比较各组间Ar-Go′、Go′-Me、Co-Gn年均生长量的差异。结果研究组患者的Ar-Go′、Go′-Me、Co-Gn年均生长量[分别为0.88(0.40,1.80)、0.67(0.15,1.18)和0.86(0.40,1.90)mm]与对照组[分别为1.08(0.45,1.60)、0.53(0.25,1.13)、1.20(0.46,2.28)mm]相比差异均无统计学意义(P均>0.05)。两组间同一性别患者、同一年龄段患者、同一颈椎成熟度分期患者,Ar-Go′、Go′-Me、Co-Gn年均生长量的差异均无统计学意义(P>0.05)。结论拔除M3牙胚对10~16岁安氏Ⅰ类错畸形正畸患者的下颌骨发育无明显影响。

Objective To investigate the effect of extraction of mandibular third molar(M3)tooth germ on the development of the mandible in orthodontic patients,with a view to providing a reference for clinical M3 tooth germ extraction.Methods One hundred and twenty-nine Angel classⅠmalocclusion patients aged 10-16 years who attended the Department of Orthodontics Division 1,School&Hospital of Stomatology,Wuhan University from 1 January 2013 to 30 December 2021 and fulfilled the criteria for nativity were included.Those who had their M3 extracted in the Department of Oral and Maxillofacial Surgery were included in the study group,with a total of 66 cases;and those who did not have their M3 extracted were included in the control group,with a total of 63 cases.The average annual growth was calculated by tracing point measurements on cephalometric films before and after orthodontic treatment according to the Jarabak and McNamara methods,with measurements of the mandibular ramus height(Ar-Go′),mandibular body length(Go′-Me),and overall mandibular length(Co-Gn)values,respectively.The average annual growth of Ar-Go′,Go′-Me,and Co-Gn were compared between the two groups for the overall sample of patients,patients of the same sex(male/female),patients of the same age group(>10 and≤12 years old,>12 and≤14 years old,>14 and≤16 years old),and patients of the same cervical vertebral maturation stage(stagesⅡ,Ⅲ,andⅣ),respectively,to see if there was any difference in the average annual growth of Ar-Go′,Go′-Me,and Co-Gn.Results There was no statistically significant difference in the average annual growth of Ar-Go′,Go′-Me,and Co-Gn between the study group[0.88(0.40,1.80),0.67(0.15,1.18),and 0.86(0.40,1.90)mm,respectively]and the control group[1.08(0.45,1.60),0.53(0.25,1.13),and 1.20(0.46,2.28)mm,respectively](P>0.05).In addition,there was no significant difference in the average annual growth in the Ar-Go′,Go′-Me,and Co-Gn between the groups for patients of the same sex group,patients of the same age group,and patients of the same cervical vertebral maturation stage group(P>0.05).Conclusions Extraction of the mandibular third molar tooth germ has no significant effect on the development of the mandible in Angle classⅠmalocclusion patients.