Mazurova Katarina, Kopp Jean-Baptiste, Renkema Anne Marie, Pandis Nikolaos, Katsaros Christos, Fudalej Piotr S
Department of Orthodontics, Palacký University Olomouc, Czech Republic.
Department of Orthodontics and Dentofacial Orthopedics, University of Bern, Switzerland.
Eur J Orthod. 2018 Apr 6;40(2):185-192. doi: 10.1093/ejo/cjx046.
To evaluate if the morphology of the mandibular symphysis is associated with the development of gingival recession.
A cohort of 177 patients was followed longitudinally for up to 5 years post-treatment. Based on the width of the symphysis, participants were divided into three groups: narrow (n = 57); average (n = 63), and wide symphysis (n = 57). Morphology of the symphysis and inclination of incisors were measured on lateral cephalometric radiographs before treatment (Ts), at the end of treatment (T0) and 5 years after treatment (T5). Gingival recession and the change of clinical crown heights in mandibular incisors were measured on plaster models made at TS, T0, and T5.
From TS to T5 the change in inclination was comparable in the narrow, average, and wide groups. At T5, gingival labial recession was present in 19.3 per cent of patients with narrow symphysis, 20.6 per cent with average symphysis, and 14 per cent of patients with wide symphysis. The difference was not significant. The mean change of clinical crown height was <1 mm (TS - T5). The regression model showed some evidence that incisor inclination at Ts might have been associated with the change of mean clinical crown height (-2.51, 95% CI: -4.6 to -0.4, P = 0.02). The logistic regression model demonstrated that H1 (Height 1) might be associated with the development of gingival recession (OR = 0.75, 95% CI: 0.58 to 0.96, P = 0.03).
Within the limitations of this study, there is no evidence that the overall morphology of the mandibular symphysis is associated with gingival recession development.
评估下颌联合的形态是否与牙龈退缩的发生有关。
对177名患者进行队列研究，纵向随访治疗后长达5年。根据联合的宽度，参与者被分为三组：窄联合（n = 57）；平均联合（n = 63）和宽联合（n = 57）。在治疗前（Ts）、治疗结束时（T0）和治疗后5年（T5）的头颅侧位片上测量联合的形态和切牙的倾斜度。在Ts、T0和T5制作的石膏模型上测量下颌切牙的牙龈退缩和临床冠高度的变化。
从Ts到T5，窄联合、平均联合和宽联合组的倾斜度变化相当。在T5时，窄联合患者中有19.3%出现牙龈唇侧退缩，平均联合患者中有20.6%出现，宽联合患者中有14%出现。差异无统计学意义。临床冠高度的平均变化<1mm（Ts - T5）。回归模型显示有证据表明Ts时切牙倾斜度可能与平均临床冠高度的变化有关（-2.51，95%CI：-4.6至-0.4，P = 0.02）。逻辑回归模型表明H1（高度1）可能与牙龈退缩的发生有关（OR = 0.75，95%CI：0.58至0.96，P = 0.03）。
在本研究的局限性内，没有证据表明下颌联合的整体形态与牙龈退缩的发生有关。
