关键词: 恒前牙, 髓室, 解剖, 变异系数

Abstract:

Objective  The aim of this study was to measure and analyze the anatomic characteristics of the pulp chamber of Chinese permanent anterior teeth radiographically. Methods  There were 137 human permanent anterior teeth to be used. The crown length, crown width and crown thickness were measured by vernier caliper. Labial-lingual and mesial-distal radiographs were obtained by parallel technique and Photoshop 8.0 was adopted for measuring the largest labial-lingual length, the largest mesial-distal length, the pulp chamber height and the distance between the lingual surface of the crown and the corresponding wall of the pulp chamber; the ratios of the largest labial-lingual length to the crown thickness, the largest mesial-distal length to the crown width and the pulp chamber height to the crown length were calculated. Finally the coefficients of variance were caculated. Results　　①The ratios of the largest mesial-distal length to the crown width of maxillary and mandibular canines were statistically different from those of the other anterior teeth. There was not statistically significant difference for those ratios either between maxillary and mandibular canines or among incisors. ②Indexes of the pulp chamber had higher variance than those of the external morphology. ③The distance between the lingual surface of the crown and the corresponding wall of the pulp chamber had the smallest coefficient of variance. ④The largest mesial-distal length of the pulp chamber had the largest coefficient of variance, except for the mandibular canines. Conclusion  This study provided anatomical basis for clinical work; the distance between the lingual surface of the crown and the corresponding wall of the pulp chamber could be used as a depth reference for the endodontic access, and the access should not be extended excessively in mesial-distal direction.

Key words: permanent anterior teeth, pulp chamber, anatomy, coefficient of variance