Stanaitytė Rūta, Trakinienė Giedrė, Gervickas Albinas
Faculty of Odontology, Medical Academy, Lithuanian University of Health Sciences.
Stomatologija. 2014;16(1):31-6.
To evaluate the changes in lower dental arch after bilateral lower third molars removal.
The study group consisted of 30 non-orthodontic patients (mean age 25,5 years, refered for bilateral lower third molars removal. Orthopantomograms and dental casts were made before and 6-8 months after surgical removal of lower third molars. Transversal lower arch widths between lower canines and second premolars and lower arch total tooth size-arch lenght discrepancy were evaluated on dental casts. The angulation of lower second premolars, first and second molars was measured in horizontal and mandibular planes on orthopantomograms.
No significant difference of inter-canine and inter-premolar transversal width was noticed. No significant changes were observed in total tooth-size lenght discrepancy, except in S1 segment consisted of first and second premolar and the canine on the right quadrant of the lower dental arch. The angulation of second premolars and first molars did not show any significant changes, however there were statistically significant changes between angulation of lower second molars on both sides.
After bilateral removal of lower third molars, lower second molars awhile showed a tendency to move backwards, but no obvious relationship between the third molar and anterior crowding was observed. Whereas the observation time is short and the patient's age is young and it can not be concluded that lower third molars cause the changes in the dental arch.
评估双侧下颌第三磨牙拔除后下颌牙弓的变化。
研究组由30例非正畸患者组成(平均年龄25.5岁,因双侧下颌第三磨牙拔除前来就诊)。在拔除下颌第三磨牙术前及术后6 - 8个月拍摄曲面断层片并制取牙模。在牙模上评估下颌尖牙与第二前磨牙之间的横向牙弓宽度以及下颌牙弓总牙量 - 牙弓长度差异。在曲面断层片上测量下颌第二前磨牙、第一磨牙及第二磨牙在水平和下颌平面的角度。
尖牙间及前磨牙间横向宽度无显著差异。除下颌牙弓右侧象限由第一、第二前磨牙及尖牙组成的S1节段外,总牙量长度差异未见显著变化。第二前磨牙及第一磨牙的角度无显著变化,但双侧下颌第二磨牙的角度变化具有统计学意义。
双侧下颌第三磨牙拔除后,下颌第二磨牙短期内有向后移动的趋势,但未观察到第三磨牙与前牙拥挤之间存在明显关联。鉴于观察时间较短且患者年龄较轻,尚不能得出下颌第三磨牙导致牙弓变化的结论。