cosmetic dentistry_ beauty & science

In 1914, Leon Williams suggested a now famous classification system of tooth shape, theorising that these three fundamental shape types are reflected inthe“KretschmericConstructionTypes”(facialout- line types). The shape of the tooth is equal to the horizontally flipped shape of the face (Figs. 7–18). For example, an athletically built person with an angular face would have square-shaped teeth (Figs.7,8,13&16).Athinpersonwithapeakedchin (leptosome) would have triangular-shaped teeth (Figs. 9, 10, 14 & 17). Today, this classification of the tooth shapes based on the shape of the face is considered to be anti- quated. Hence, it only serves as a very rough general guide when selecting a set of anterior acrylic teeth for a patient case. In the fifties, the “dentogenic concept” by Frush and Fisher spread across the US andthentootherpartsoftheworld.Accordingtothis concept, a “personality spectrum” can also be added to help obtain the shape of the tooth. Next to clini- cal, intra-oral and facial relation considerations, the age, sex, and other characteristics of the patient are Figs. 7 & 8_An athletically built person with an angular face (square). The labial tooth shape resembles the reversed shape of the face. Figs. 9 & 10_The leptosome tooth shape of a thin or skinny person with the individual characteristics of the marginal ridges. Figs. 11 & 12_Person with a rounded (ovoid) form of the face (pyknic) and the ovoid tooth shape with the individual characteristics of the marginal ridges. Fig. 13_Even from the incisal aspect, the respective shape characteristics are visible. Fig. 14_The triangular type (leptosome) with an introverted labial surface. Fig. 15_The ovoid type (pyknic) with an extroverted labial surface. Fig. 16_Detailed characteristics when viewed from the approximal. Fig. 17_Detailed characteristics of the triangular tooth shape. Fig. 18_Detailed characteristics of the ovoid tooth shape. I 15 special _ prosthetic techniques I cosmeticdentistry 4_2011 Fig. 7 Fig. 9 Fig. 11 Fig. 8 Fig. 10 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18