Valencia University Medical and Dental School, Valencia, Spain.
Med Oral Patol Oral Cir Bucal. 2011 Jan 1;16(1):e100-4. doi: 10.4317/medoral.16.e100.
Gummy smile constitutes a relatively frequent aesthetic alteration characterized by excessive exhibition of the gums during smiling movements of the upper lip. It is the result of an inadequate relation between the lower edge of the upper lip, the positioning of the anterosuperior teeth, the location of the upper jaw, and the gingival margin position with respect to the dental crown. Altered Passive Eruption (APE) is a clinical situation produced by excessive gum overlapping over the enamel limits, resulting in a short clinical crown appearance, that gives the sensation of hidden teeth. The term itself suggests the causal mechanism, i.e., failure in the passive phase of dental eruption, though there is no scientific evidence to support this. While there are some authors who consider APE to be a risk situation for periodontal health, its clearest clinical implication refers to oral esthetics. APE is a factor that frequently contributes to the presence of a gummy or gingival smile, and it can easily be corrected by periodontal surgery. Nevertheless, it is essential to establish a correct differential diagnosis and good treatment plan. A literature review is presented of the dental eruption process, etiological hypotheses of APE, its morphologic classification, and its clinical relevance.
Gummy 微笑是一种相对常见的美学改变，其特征是在上唇微笑运动时过多地露出牙龈。它是由以下几个因素之间的不协调关系造成的：上唇的下缘、前牙的位置、上颌骨的位置以及牙龈边缘相对于牙冠的位置。被动萌出异常（APE）是一种临床情况，由于牙龈过度覆盖牙釉质边界，导致临床牙冠变短，给人以牙齿隐藏的感觉。这个术语本身就暗示了其因果机制，即牙齿萌出的被动阶段失败，尽管没有科学证据支持这一点。虽然有些作者认为 APE 是牙周健康的危险因素，但它最明显的临床意义是涉及口腔美观。APE 是导致龈笑或牙龈笑的一个常见因素，通过牙周手术很容易纠正。然而，建立正确的鉴别诊断和良好的治疗计划是至关重要的。本文对牙齿萌出过程、APE 的病因假说、其形态学分类及其临床相关性进行了文献回顾。
