对佛山地区14岁儿童第三磨牙发育状况的研究

Study on development of the third molar of the fourteen-year-olds in Foshan

目的通过曲面断层X线片了解第三磨牙(M3)的发育状况。方法选取佛山市口腔医院放射科就诊的14岁儿童的X线片160例,男女各半。采用Demirjian分析法评估M3的发育阶段,比较不同性别、上下颌、左右侧M3的发育状况。结果 14岁儿童大多处于E期,男性占43.44%,女性占48.44%;上颌M3发育主要集中处于E期,下颌M3发育主要处于D、E期,上颌发育较下颌早;左右侧M3发育分期无差异。结论 14岁儿童M3牙根已经开始发育,上颌的发育早于下颌。

Objective To study the development of the 3rd molar of the fourteen-year-olds children in foshan by X-ray films. Methods Randomly selected 160 panoramic radiographs of fourteen-year-olds from the database of Stomatological Hospital of Foshan city were divided by the development degree of third molars into several phrases to analyze the development status according to different genders, the left and right sides, the maxilla and the mandible. Results Most of the M3 was in stage E,the occurrence ratio was 43.44% in male and 48.44% in female;most of the M3 was in stage E in maxillary and in stage D and E in mandible; there was no significant differences between right and left sides about the development degree of third molars. Conclusion The tooth root of the third molar of the fourteen-year-olds have develped, and the maxillary third molars appeared earlier than mandible ones.