Kapagiannidis D, Kontonasaki E, Bikos P, Koidis P
Department of Fixed Prosthesis and Implant Prosthodontics, Dental School, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
J Oral Rehabil. 2005 Nov;32(11):830-7. doi: 10.1111/j.1365-2842.2005.01517.x.
There is limited knowledge concerning tooth and gingival display in the maxillary premolar area during smiling. The purpose of this study was to investigate maxillary premolar and associated gingival display during smiling, and to reveal possible differences related to gender and age. The study consisted of 90 males and 113 females (mean age 38 years, s.d. = 13.83) receiving regular dental care. Two pictures of each subject, one with lips in maximum smile, and the other a retracted frontal view, were made. Clinical crown length, tooth and gingival display were measured for the left maxillary premolars. Central incisors and canines were used as controls. anova with Bonferroni post hoc multiple comparisons tests was used to assess any statistically significant impact of gender and age on tooth and gingival display, and determine differences among gender and age groups (at 5% significance level). Premolars were partially visible in more than 80% of the smiles, and displayed more than 65% of their clinical crown length during smiling. The least display (P < 0.001) was recorded for first and the greatest for second premolars. Tooth display was greater in females, but statistically significant only in central incisors (P < 0.05). No significant differences were revealed between age subgroups. Gingival display was greater for premolars compared with both central incisors (P < 0.001) and canines (P < 0.05). Displayed gingiva was found in first and second premolars in 44 and 49% of subjects, respectively. More gingival display was recorded in females and in younger subjects.
关于微笑时上颌前磨牙区域的牙齿和牙龈显露情况，目前了解有限。本研究的目的是调查微笑时上颌前磨牙及相关牙龈的显露情况，并揭示与性别和年龄相关的可能差异。该研究纳入了90名男性和113名女性（平均年龄38岁，标准差 = 13.83），他们均接受常规牙科护理。为每位受试者拍摄两张照片，一张是嘴唇最大程度微笑时的照片，另一张是正面回缩视图照片。测量左侧上颌前磨牙的临床冠长、牙齿和牙龈显露情况。以中切牙和尖牙作为对照。采用方差分析及Bonferroni事后多重比较检验，评估性别和年龄对牙齿和牙龈显露的任何统计学显著影响，并确定性别和年龄组之间的差异（显著性水平为5%）。在超过80%的微笑中，前磨牙部分可见，且微笑时露出超过其临床冠长的65%。第一前磨牙的显露最少（P < 0.001），第二前磨牙的显露最多。女性的牙齿显露更多，但仅在中切牙上具有统计学显著性（P < 0.05）。年龄亚组之间未发现显著差异。与中切牙（P < 0.001）和尖牙（P < 0.05）相比，前磨牙的牙龈显露更多。分别在44%和49%的受试者中，第一和第二前磨牙出现牙龈显露。女性和年轻受试者的牙龈显露更多。
