Arslan Hakan, Capar Ismail Davut, Ertas Elif Tarim, Ertas Huseyin, Akcay Merve
Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkiye.
Department of Endodontics, Faculty of Dentistry, Izmir Katip Celebi University, Izmir, Turkiye.
Eur J Dent. 2015 Jan-Mar;9(1):11-19. doi: 10.4103/1305-7456.149632.
The purposes of this retrospective study were to represent a newly designed theoretical model for determining orifice shape and morphologic properties of mandibular premolars and to correlate these findings with each other.
A total of 287 mandibular premolar images obtained from 88 patients by cone-beam computed tomography were included in this study. The measurements were performed below the cementoenamel junction, and different orifice configurations were defined in accordance with various ratios. The age and gender of the patient, the tooth type and position, the number of roots, orifice configuration, root canal configuration, presence of C-shaped canal, and the presence of radicular groove were recorded. It was also recorded whether the root canal becomes round or not and if any, length of the root canal from the orifice to the section in which it becomes round. Furthermore, the theoretical model for determining orifice shape was defined after measurements. The orifice shape was determined as round, oval, flat, keyhole-shaped, and T-shaped, and orifices with short, normal length, and long isthmus. Statistical analyses were performed using Chi-square and Spearman's rank correlation tests (P = 0.05).
Orifice configurations were, usually, flat (37%), or keyhole-shaped (23%). The prevalence of T-shaped was found to be 3.8%. The prevalence of C-shaped canals was found to be 2.1%. The percentage of root canals that became round in the middle or apical thirds was 95.1%. Radicular grooves were detected in 37 (24%) of first premolars and six (4.5%) of second premolars. Statistical analysis revealed that the mean length of distance until the canal reached a round shape varied according to age group (r = -0.270; P < 0.001). There was a statistically significant difference between radicular groove and tooth type (P < 0.001).
The mean length of distance until the canal reached a round shape correlated with the patient's age. The new theoretical model could be beneficial to determine orifice configurations.
本回顾性研究的目的是提出一种新设计的理论模型，用于确定下颌前磨牙的根管口形状和形态学特征，并将这些发现相互关联。
本研究纳入了通过锥形束计算机断层扫描从88例患者获得的287张下颌前磨牙图像。测量在牙骨质牙釉质界下方进行，并根据不同比例定义不同的根管口形态。记录患者的年龄和性别、牙齿类型和位置、牙根数量、根管口形态、根管形态、C形根管的存在情况以及根面沟的存在情况。还记录根管是否变圆，以及如果变圆，从根管口到其变圆处的根管长度。此外，在测量后定义了确定根管口形状的理论模型。根管口形状确定为圆形、椭圆形、扁平形、钥匙孔形和T形，以及峡部短、正常长度和长的根管口。使用卡方检验和Spearman等级相关性检验进行统计分析（P = 0.05）。
根管口形态通常为扁平形（37%）或钥匙孔形（23%）。发现T形的患病率为3.8%。发现C形根管的患病率为2.1%。在根管中三分之一或根尖三分之一处变圆的根管百分比为95.1%。在37颗（24%）第一前磨牙和6颗（4.5%）第二前磨牙中检测到根面沟。统计分析显示，直到根管变圆的平均距离长度根据年龄组而变化（r = -0.270；P < 0.001）。根面沟与牙齿类型之间存在统计学显著差异（P < 0.001）。
直到根管变圆的平均距离长度与患者年龄相关。新的理论模型可能有助于确定根管口形态。
