Fayyad M A, al-Obaida M I, Jamani K D
University of Jordan, Faculty of Dentistry, Amman, Jordan.
Quintessence Int. 1995 May;26(5):325-9.
The cervical margins of crowns are often placed subgingivally to satisfy patients' demands for esthetics, even though subgingival margins can adversely affect gingival health. Photographs of 527 Saudi citizens (285 men and 242 women) with natural and exaggerated smiles were recorded to determine if subgingival margins are always necessary. The photographs indicated that a substantial percentage of the participants did not display the gingival tissue of their anterior teeth during a natural smile. (Percentages ranged from 43.5% to 69.8% of maxillary teeth and from 93.7% to 97.9% of mandibular teeth). The percentage of subjects who did not reveal the gingival tissue of their maxillary anterior teeth during an exaggerated smile ranged from 22.7% to 39.3%; the percentage of mandibular anterior teeth ranged from 54.1% to 72.7%. There was no statistically significant difference between men and women regarding visibility of anterior teeth. Thus, a substantial number of these subjects could receive anterior crowns with supragingival margins without sacrificing esthetics.
尽管龈下边缘会对牙龈健康产生不利影响，但为了满足患者对美观的需求，牙冠的颈部边缘通常放置在龈下。记录了527名沙特公民（285名男性和242名女性）自然微笑和夸张微笑的照片，以确定龈下边缘是否总是必要的。照片显示，相当一部分参与者在自然微笑时并未露出前牙的牙龈组织。（上颌牙的比例范围为43.5%至69.8%，下颌牙的比例范围为93.7%至97.9%）。在夸张微笑时未露出上颌前牙牙龈组织的受试者比例范围为22.7%至39.3%；下颌前牙的比例范围为54.1%至72.7%。在前牙可见性方面，男性和女性之间没有统计学上的显著差异。因此，这些受试者中的相当一部分人可以接受带有龈上边缘的前牙冠，而不会牺牲美观。
