Contemporary Facial Evaluation
A Figure 3.19A. Insufficient teeth display due to upper lip deformity that warrants correction.
B Figure 3.19B. Corrected teeth display via lip augmentation therapy.
ness, and character will determine how much of the restoration should be displayed while smiling or with the lip in any other position.
Teeth Morphology Attempts to solve esthetic problems in this age of scientific revolution led dentists to seek an evidence-based concept. This search for esthetic success with dental restorations was led by Williams (1914) but involved many other ideas and authors as well (Wavrin 1920, Young 1954). While credit is often given to Williams, Hall (1886) was the first to describe what he believed was a correlation between face form and tooth form. He stated that three basic forms of teeth existed: square, tapering, and ovoid (Stein 1936). The correlation succeeded due to its practicality and manufacturer support, and not because of any actual relationship (Young 1954).
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However, most of the research has shown that no significant correlation exists between facial form and tooth form (Sellen et al. 1998) because it is clinically complicated by different facial form appearances due to age, hairstyle, eyewear, and body mass changes. Furthermore, no significant correlation exists because of the vast variety of facial forms and the fact that the amazing face creation cannot be confined within limited forms and formulas. In all cases, the guidelines that will be reviewed within this topic are considered to be only relative guides to the overall appearance, rather than rules to be followed. The correct understanding of the dental morphology of humankind allows us to create natural looking implant-supported prostheses. Lombardi (1973) detailed the artificial teeth characters and their impact on the smile design and final treatment results. Studying the standard anatomical object characters of natural teeth with which people are born has led the way to a wealth of knowledge and information that can be valuable in any esthetic reconstructive procedure. Age, gender, personality, habits, tooth position, shade, illumination, and illusion all influence the selection of the shape of the anterior maxillary teeth either in fully or partially edentulous cases. In cases of restoring missing maxillary teeth in the esthetic zone with or without dental implants, the clinician should strive to fabricate identical restorations that almost replicate natural missing dentition. If the missing teeth cannot be used as a reference due to their absence, then other references may be used as a guide. Therefore, the relationship between teeth form and the human face becomes poorly evidenced while the relationship between teeth, characters, and extraoral or intraoral factors become more logical.
Age The morphological characters of anterior maxillary teeth are strongly influenced by the patient’s age. In young individuals, the central and lateral incisors are long and rectangular, which emphasizes youthfulness. (See Figures 3.20A–B.) In older individuals, the front teeth often get worn and lose their rectangular shape, become square in shape due to incisal micro- or macrocracks, and sometimes attain up-fractions. The central incisors grow shorter due to parafunction, gingival recession, enamel cracks, and faulty dentistry. Less tooth structure will be visible when smiling. Small-sized incisal embrasures occur, whereas the gingival embrasures widen as a result of the recession of the gingiva (Goldstein 1998). Flat broad incisal edges and functional or parafunctional generalized attrition results in posterior wear of the dentition. This excessive wear can eventually lead to