Appropriate proportions as guidelines in selection of anterior denture teeth
Nikola Petričević1, Asja Čelebić1, Lejla Ibrahimagić-Šeper2, Ivan Kovačić3
Department of Prosthodontics, School of Dental Medicine, University of Zagreb, Croatia; 2 Health Centre Zenica, Bosnia and Herzegovina; 3 Dental Polyclinic, Split, Croatia
ABSTRACT Aim To examine width-to-length andtooth-to-tooth width ratios of maxillary anterior teeth and to compare the obtained proportions with the width-to-length ratio of the hard palate, the Golden Proportion and the 75 % Proportion. Methods The widths and the lengths of the clinical crowns of the maxillary anterior teeth were measured. Hard palate width and length were measured. Width-to-length ratio of the hard palate was calculated, aswell as width-to-length ratios of the maxillary anterior teeth. Further, tooth-to-tooth width ratios were calculated for all maxillary anterior teeth. Results Comparison between width-to-length ratios of the maxillary anterior teeth and the 75 % Proportion, the Golden Proportion and the proportion of hard palate revealed statistically significant differences (p0.05). There was no statisticallysignificant difference between men and women (independent t test, p>0.05). There was also no significant difference between tooth dimensions on the left and the right side of the dental arch (paired t test, p>0.05). Therefore, mean values for the maxillary anterior teeth dimensions and for the hard palate dimensions were calculated. Mean values of the anterior maxillary teeth dimensions are presentedin Figure 1 and mean values of the hard palate width and length are presented in Figure 2. The width-to-length ratios of the hard palate and of the maxillary anterior teeth, as well as tooth-to-tooth ratios of the maxillary anterior teeth are presented in Table 1.
* W1, width of the maxillary central incisor; W2, width of the maxillary lateral incisor; W3, width of the maxillary canine; L1,length of the maxillary central incisor; L2, length of the maxillary lateral incisor; L3, length of the maxillary canine
Figure 1. Means and standard deviations for the maxillary anterior teeth width and length*
Figure 2. Means and standard deviations of the hard palate width (hamular width) and length (palatine foveas- papilla incisiva)
Medicinski Glasnik, Volume 5, Number 2,August 2008
The significance of the differences between the width-to-length ratio of the hard palate and of the maxillary anterior teeth is presented in Table 2. The significance of the difference between the width-to-length ratio of the maxillary anterior teeth and the 75% Proportion and the Golden Proportion, as well as between tooth-to-tooth ratios of maxillary anterior teeth and the GoldenProportion and the 75% proportion are presented in the Table 3. DISCUSSION Decision on the selection of appropriate artificial teeth has to be based on proper dimensions and proportions. Since the position of maxillary anterior teeth has the strongest influence on esthetics (19) and only few guidelines describe their proportions (16, 17), it seemed reasonable to perform the study to define the ‘averageproportions’ in intact dentition, and to compare them with the Golden Proportion and the 75 % Proportion, since those proportions have been proposed in the literature as guidelines for artificial teeth selection (23). Number of subjects is relatively small due to the fact that this study is actually a pilot study and may be an introduction to a greater investigation in this field of dentistry.All subjects were 18-30 years old since the inclusion criteria were finished craniofacial development and no tooth wear, no fillings and no proshodontic appliances on frontal teeth. In older population the first signs of tooth wear exist on the frontal teeth. The greater number of female examinees in this study is a result of more frequent exclusion of males due to the tooth wear or fillings on...