Abstract：
OBJECTIVE: In this study, we examined the facial, dental, periodontal, and tomographic features associated with excessive gingival display (EGD) when smiling in young adults self-reporting a \"gummy smile,\" categorized by potential etiology.
METHODS: The study included 25 healthy adults (18-42 years old; 23 women and 2 men) who self-reported EGD. Participants completed a health questionnaire and underwent a periodontal examination assessing probing depth, clinical attachment level, keratinized gingival width, and gingival thickness (GT). Extraoral and intraoral photographs were taken for smile analysis and to determine facial and dental characteristics. Cone-beam computed tomography (CBCT), performed with a lip retractor in place, was used to measure the distance from the gingival margin (GM) to the cementoenamel junction (CEJ), the distance from the CEJ to the alveolar crest, buccal bone thickness, and GT. The extent of EGD when smiling was quantified as the distance from the GM at the upper central incisor to the upper lip edge when smiling fully. The smile was categorized into 4 types based on gingival exposure characteristics observed during full smile.
RESULTS: Most participants were female (92%), with a mean age of 28.77±6.56 years. The average EGD was 4.2±2.44 mm, extending bilaterally from the anterior to the posterior maxilla. Two primary etiological factors were identified, alone or in combination: vertical maxillary excess (VME), predominantly indicated by an anterior maxillary height greater than 29 mm and a large interlabial gap; and altered passive/active eruption (APE), primarily characterized by square teeth (64%), upper central incisor width-to-height ratio (CIW:CIH) exceeding 87.5%, and GM-CEJ distance on CBCT exceeding 2 mm.
CONCLUSIONS: These findings suggest a multifactorial etiology of EGD, primarily associated with VME and APE. Clinical periodontal examination, CBCT conducted with a lip retractor, CIW:CIH, and soft tissue facial cephalometric analysis may aid in identifying the etiological factors of EGD.
METHODS: The study included 25 healthy adults (18-42 years old; 23 women and 2 men) who self-reported EGD. Participants completed a health questionnaire and underwent a periodontal examination assessing probing depth, clinical attachment level, keratinized gingival width, and gingival thickness (GT). Extraoral and intraoral photographs were taken for smile analysis and to determine facial and dental characteristics. Cone-beam computed tomography (CBCT), performed with a lip retractor in place, was used to measure the distance from the gingival margin (GM) to the cementoenamel junction (CEJ), the distance from the CEJ to the alveolar crest, buccal bone thickness, and GT. The extent of EGD when smiling was quantified as the distance from the GM at the upper central incisor to the upper lip edge when smiling fully. The smile was categorized into 4 types based on gingival exposure characteristics observed during full smile.
RESULTS: Most participants were female (92%), with a mean age of 28.77±6.56 years. The average EGD was 4.2±2.44 mm, extending bilaterally from the anterior to the posterior maxilla. Two primary etiological factors were identified, alone or in combination: vertical maxillary excess (VME), predominantly indicated by an anterior maxillary height greater than 29 mm and a large interlabial gap; and altered passive/active eruption (APE), primarily characterized by square teeth (64%), upper central incisor width-to-height ratio (CIW:CIH) exceeding 87.5%, and GM-CEJ distance on CBCT exceeding 2 mm.
CONCLUSIONS: These findings suggest a multifactorial etiology of EGD, primarily associated with VME and APE. Clinical periodontal examination, CBCT conducted with a lip retractor, CIW:CIH, and soft tissue facial cephalometric analysis may aid in identifying the etiological factors of EGD.
摘要：
目的：在本研究中，我们检查了面部,牙科,牙周,以及与年轻成年人微笑时过度牙龈显示（EGD）相关的断层特征，“按潜在病因分类。
方法：该研究包括25名健康成年人（18-42岁；23名女性和2名男性），他们自我报告了EGD。参与者完成了健康问卷，并进行了牙周检查，评估了探查深度，临床依恋水平，角化牙龈宽度，和牙龈厚度（GT）。拍摄口外和口内照片以进行微笑分析并确定面部和牙齿特征。锥形束计算机断层扫描（CBCT），在嘴唇牵开器到位的情况下进行，用于测量从牙龈边缘（GM）到牙釉质交界处（CEJ）的距离，从CEJ到肺泡的距离，颊骨厚度,和GT。微笑时EGD的程度被量化为完全微笑时从上中央切牙处的GM到上唇边缘的距离。根据在满脸微笑期间观察到的牙龈暴露特征，将微笑分为4种类型。
结果：大多数参与者是女性（92％），平均年龄28.77±6.56岁。平均EGD为4.2±2.44mm，从上颌骨前部向后部两侧延伸。确定了两个主要的病因，单独或组合：垂直上颌过量（VME），主要表现为上颌前高度大于29毫米和阴唇间间隙大；被动/主动萌出改变（APE），主要特征是方齿(64%)，上中切牙宽高比(CIW:CIH)超过87.5%,CBCT上的GM-CEJ距离超过2mm。
结论：这些发现提示EGD的多因素病因，主要与VME和APE相关。临床牙周检查，用嘴唇牵开器进行CBCT，CIW:CIH,面部软组织头影测量分析可能有助于确定EGD的病因。
方法：该研究包括25名健康成年人（18-42岁；23名女性和2名男性），他们自我报告了EGD。参与者完成了健康问卷，并进行了牙周检查，评估了探查深度，临床依恋水平，角化牙龈宽度，和牙龈厚度（GT）。拍摄口外和口内照片以进行微笑分析并确定面部和牙齿特征。锥形束计算机断层扫描（CBCT），在嘴唇牵开器到位的情况下进行，用于测量从牙龈边缘（GM）到牙釉质交界处（CEJ）的距离，从CEJ到肺泡的距离，颊骨厚度,和GT。微笑时EGD的程度被量化为完全微笑时从上中央切牙处的GM到上唇边缘的距离。根据在满脸微笑期间观察到的牙龈暴露特征，将微笑分为4种类型。
结果：大多数参与者是女性（92％），平均年龄28.77±6.56岁。平均EGD为4.2±2.44mm，从上颌骨前部向后部两侧延伸。确定了两个主要的病因，单独或组合：垂直上颌过量（VME），主要表现为上颌前高度大于29毫米和阴唇间间隙大；被动/主动萌出改变（APE），主要特征是方齿(64%)，上中切牙宽高比(CIW:CIH)超过87.5%,CBCT上的GM-CEJ距离超过2mm。
结论：这些发现提示EGD的多因素病因，主要与VME和APE相关。临床牙周检查，用嘴唇牵开器进行CBCT，CIW:CIH,面部软组织头影测量分析可能有助于确定EGD的病因。
