Şatır Samed, Büyükçavuş Muhammed Hilmi
Department of Oral and Maxillofacial Radiology, Akdeniz University School of Dentistry, Antalya, Turkey.
Department of Orthodontics, Süleyman Demirel University School of Dentistry, Isparta, Turkey.
Turk J Orthod. 2019 Dec 1;32(4):195-199. doi: 10.5152/TurkJOrthod.2019.18011. eCollection 2019 Dec.
This study aimed to evaluate the unerupted mandibular second premolar (MnP2) angulation in individuals with different tooth agenesis in Turkish population.
We retrospectively reviewed panoramic radiographs of patients treated at Akdeniz University. According to the agenesis, the subjects were categorized into three groups: 22 patients with unilateral MnP2 agenesis (Group 1), 22 patients with bilateral mandibular incisor agenesis (MnI, Group 2), and 22 patients with no agenesis excluding third molars (Group 3). The angle between the first mandibular molar and unerupted MnP2 (ɣ angle) and the angle between the mandibular basis and unerupted MnP2 (Ɵ angle) were measured on both the right and left sides in Groups 2 and 3 using the method determined by Shalish et al.
Groups 1 and 2 were compared with the control group with respect to (ɣ) and (Ɵ). No significant difference was found between Groups 2 and 3 on both the right and left sides (p>0.05). The comparison between Groups 1 and 3 revealed significant differences in the ɣ and Ɵ angle only on the left side (p>0.05).
Posterior rotation of the mandibular condyle during the growth-development period may be one of the factors responsible for the difference in the Ɵ angle between the MnI agenesis and control groups. A difference in the total number of teeth on the dental arch may be a reason for the differences in the ɣ angle between the MnI agenesis and control groups.
本研究旨在评估土耳其人群中不同牙齿发育不全个体未萌出的下颌第二前磨牙(MnP2)的角度。
我们回顾性分析了阿克德尼兹大学治疗患者的全景X线片。根据发育不全情况,将受试者分为三组:22名单侧MnP2发育不全患者(第1组),22名双侧下颌切牙发育不全患者(MnI,第2组),以及22名除第三磨牙外无发育不全的患者(第3组)。使用Shalish等人确定的方法,在第2组和第3组的左右两侧测量第一下颌磨牙与未萌出的MnP2之间的角度(γ角)以及下颌骨基部与未萌出的MnP2之间的角度(θ角)。
比较第1组和第2组与对照组的(γ)和(θ)。第2组和第3组在左右两侧均未发现显著差异(p>0.05)。第1组和第3组之间的比较仅在左侧的γ角和θ角上显示出显著差异(p>0.05)。
生长发育期下颌髁突的后旋可能是MnI发育不全组与对照组θ角差异的原因之一。牙弓上牙齿总数的差异可能是MnI发育不全组与对照组γ角差异产生的原因。