Bidra Avinash S, Persenaire Mitchell, Kuo Chia-Ling
Department of Reconstructive Sciences, University of Connecticut Health Center, Farmington, CT.
Private Practice, Fayetteville, AK.
J Prosthodont. 2021 Dec;30(9):769-775. doi: 10.1111/jopr.13344. Epub 2021 Feb 25.
To assess if there are any differences in maxillary dentogingival exposure between different facial expressions (maximum smile with eyes open and eyes closed), age groups and both sexes.
Digital photographs of the lower third of the face of 120 subjects, belonging to 6 different age groups were taken. There were 20 subjects in each of the 6 age groups (20-30, 30-40, 40-50, 50-60, 60-70, and 70-80) which were comprised of 80 women and 40 men. Two standardized images of each subject were taken, one of maximum smile with eyes open, and the second of maximum smile with eyes closed. These 240 images were used to quantify a dentogingival exposure ratio (DER) for each tooth spanning the second bicuspids on either side, using standardized measurement techniques. Additionally, incidence of interdental papilla visibility was studied in a binary manner, and all data were studied with respect to various covariables of age, sex and type of facial expression using a generalized linear mixed effects model. A p-value < 0.05 was determined to be statistically significant.
There was a statistically significant difference between the dentogingival exposure ratio (DER) for all images with eyes open and eyes closed per tooth location studied, across all age groups (p ≤ 0.001) and both sexes, suggesting that subject images of smiles with eyes closed had significantly higher dentogingival exposure. There was a decreasing trend of DER with increasing age groups when eyes were open (p = 0.005) and when eyes were closed (p = 0.042), suggesting that older subjects had lower dentogingival exposure. With respect to sex, there was no statistically significant difference in mean DER between males and females, when eyes were open (p = 0.430) and closed (p = 0.351). The incidence of interdental papilla exposure also differed significantly between images with eyes open and eyes closed across all age groups (p ≤ 0.001). However, the incidence of interdental papilla exposure decreased with age, only in images with eyes open (p < 0.001) but was not statistically significant among images with eyes closed (p = 0.127). With respect to sex, there was a significant difference in incidence of interdental papilla exposure in images with eyes open (p = 0.029) but no significant difference when eyes were closed (p = 0.782).
Maxillary dentogingival exposure decreases with increasing age and is significantly higher when recording maximum smile with eyes closed, for all age groups and both sexes. As this is a simple and clinically reproducible facial expression, incorporating patient's maximum smiling images with eyes closed may be routinely necessary for complete and accurate data collection for prosthodontic treatment planning purposes.
评估不同面部表情（睁眼最大微笑和闭眼最大微笑）、年龄组以及男女之间上颌牙牙龈暴露情况是否存在差异。
拍摄了属于6个不同年龄组的120名受试者面部下三分之一的数码照片。6个年龄组每组有20名受试者（20 - 30岁、30 - 40岁、40 - 50岁、50 - 60岁、60 - 70岁和70 - 80岁），其中包括80名女性和40名男性。为每位受试者拍摄两张标准化图像，一张是睁眼最大微笑，另一张是闭眼最大微笑。使用标准化测量技术，对这240张图像两侧第二双尖牙之间的每颗牙齿进行牙龈暴露率（DER）量化。此外，以二元方式研究牙间乳头可见度的发生率，并使用广义线性混合效应模型，针对年龄、性别和面部表情类型的各种协变量对所有数据进行研究。p值<0.05被确定为具有统计学意义。
在所研究的每个牙齿位置，所有年龄组（p≤0.001）和男女中，睁眼和闭眼的所有图像的牙龈暴露率（DER）之间存在统计学显著差异，这表明闭眼微笑的受试者图像具有明显更高的牙龈暴露。当睁眼（p = 0.005）和闭眼（p = 0.042）时，DER随年龄组增加呈下降趋势，这表明年龄较大的受试者牙龈暴露较低。就性别而言，睁眼（p = 0.430）和闭眼（p = 0.351）时，男性和女性的平均DER在统计学上无显著差异。所有年龄组中，睁眼和闭眼图像之间牙间乳头暴露的发生率也存在显著差异（p≤0.001）。然而，牙间乳头暴露的发生率仅在睁眼图像中随年龄下降（p<0.001），而在闭眼图像中无统计学意义（p = 0.127）。就性别而言，睁眼图像中牙间乳头暴露的发生率存在显著差异（p = 0.029），但闭眼时无显著差异（p = 0.782）。
对于所有年龄组和男女，上颌牙牙龈暴露随年龄增加而减少，并且在记录闭眼最大微笑时显著更高。由于这是一种简单且临床可重复的面部表情，为了进行完整准确的修复治疗计划数据收集，常规情况下可能需要纳入患者闭眼最大微笑的图像。
