Al Wazzan Khalid A
Department of Prosthetic Dental Sciences at the King Saud University College of Dentistry in Riyadh, The Kingdom of Saudi Arabia.
J Contemp Dent Pract. 2004 Feb 15;5(1):53-62.
The visibility of anterior tooth surfaces with lips at rest or during function is an important factor in determining prosthodontic outcome. There is a lack of sufficient information published on this subject. The aim of this study was to investigate the degree of visibility of maxillary and mandibular anterior teeth surfaces when the lips are at rest. Four hundred seventy three adults were examined. All the subjects had maxillary and mandibular anterior teeth present with no caries, restorations, severe attrition, mobility, extrusion, or obvious deformities. The portions of anterior teeth that were visible were measured vertically using a Boley gauge from the border of the lip to the incisal edge for the incisors and to the cusp tip for the canines. The measurement was taken at the midpoint of the tooth when the lips and lower jaw were at the rest position. The length of the upper lip was measured from the base of the columella to the tip of the philtrum at the midline of the face. Males showed more of the maxillary lateral, canine, and mandibular anterior teeth than females. With increasing age, the amount of maxillary anterior teeth that was visible at rest decreased. The subjects with shorter upper lips displayed more maxillary central incisor structure than those with longer upper lips. Racial differences were not found. The amount of visible portions of anterior teeth is determined by muscle positions that vary from person to another. It provides an excellent starting point for vertical positioning anterior teeth that can be modified as necessary in any clinical situation. The findings of this study should help the dentist in providing aesthetic prosthodontic treatment that involves replacement of anterior teeth. A useful guideline for positioning anterior teeth is suggested.
在前牙静止或行使功能时，前牙表面的可见度是决定修复效果的一个重要因素。关于这个主题发表的信息不足。本研究的目的是调查唇部静止时上颌和下颌前牙表面的可见度。对473名成年人进行了检查。所有受试者的上颌和下颌前牙均无龋齿、修复体、严重磨损、松动、伸长或明显畸形。使用博利测径器从唇部边缘垂直测量前牙可见部分的长度，对于切牙，测量至切缘；对于尖牙，测量至牙尖。测量在唇部和下颌处于静止位置时牙齿的中点进行。上唇长度从鼻小柱基部测量至面部中线处人中的尖端。男性比女性上颌侧切牙、尖牙和下颌前牙的可见部分更多。随着年龄的增加，静止时可见的上颌前牙数量减少。上唇较短的受试者比上唇较长的受试者显示出更多的上颌中切牙结构。未发现种族差异。前牙可见部分的数量由因人而异的肌肉位置决定。它为前牙的垂直定位提供了一个很好的起点，可在任何临床情况下根据需要进行调整。本研究的结果应有助于牙医提供涉及前牙替换的美学修复治疗。提出了一个有用的前牙定位指南。
