The purpose of this investigation was to analyze the clinical crown of the 3 tooth groups of the maxillary anterior sextant of the permanent dentition of normal subjects with respect to (i) width, length and the width/length ratios and (ii) determine if there is a correlation between tooth dimensions or tooth group ratios and subject height. Subjects (> or = 20 y.o.) were recruited for this study if (i) the free gingival margin on the facial surface of teeth in the maxillary sextant was positioned apical to the cervical bulge, (ii) there was no evidence of attachment loss; as determined by lack of a detectable CEJ and (iii) the marginal tissue was knife edged in form, firm in consistency and coral pink in color. Teeth were excluded if (i) there was evidence of gingival alteration, i.e., gingival overgrowth/hyperplasia, inflammation, altered passive eruption, attachment loss, gingival recession or history of periodontal surgery, or (ii) there was evidence or history of incisal edge/proximal tooth alteration as in, i.e., restorative intervention, traumatic injury or occlusal wear into dentin. At least 1 suitable tooth from each tooth group of the maxillary anterior dentition had to be present. A maxillary impression was taken and poured in yellow die stone. The widest mesial-distal portion and the longest apical-coronal portion of the test teeth were measured. Gender, ethnicity and subject height (SH) were recorded for each participant. Due to a limited ethnic diversity only data from the Caucasian group were analyzed. The mean coronal tooth width (mm) of males versus females was CI: 8.59 versus 8.06, LI: 6.59 versus 6.13 and CA: 7.64 versus 07.15. The mean coronal tooth length (mm) of males versus females was CI: 10.19 versus 9.39, LI: 8.70 versus 7.79 and CA: 10.06 versus 8.89. All width and length measures were significantly greater for males than for females. The mean coronal tooth width/length ratios for males versus females was CI: 0.85 versus 0.86, LI: 0.76 versus 0.79 and CA: 0.77 versus 0.81. A comparison between genders of the width/length ratios of the CI and LI were found not to differ, however the CA ratio for females was significantly greater than for males. A statistically significant difference was found to exist between the mean (cm) SH for males versus females: 181.2 versus 164.0. A positive correlation (p < or = 0.0001 to 0.0691) was found to exist between tooth group width/height ratios within genders. No significant correlation was found between any of the tooth dimensions or tooth group ratios and SH. The results of this study indicate that within male and female Caucasians, the mean width/length ratio of the maxillary 3 anterior tooth groups is 0.81. As well, within both genders there is a positive correlation between tooth group width/length ratios. The significance of these findings with respect to periodontal mucogingival plastic surgical procedures is discussed.

Purpose: The purpose of this study was to determine if bleaching extends beyond the borders of a shortened tray or if a demarcation line is found. Materials and Methods: Fifteen extracted teeth were selected darker than B2 on a Vita Lumin Shade guide (Vita Lumin, Bad Sackingen, Germany). The teeth were mounted in arch‐like fashion in dental stone. Alginate impressions were made, and a stone replica of the four arches of teeth was generated. Vacuum‐formed bleaching trays were fabricated for each arch, without and with reservoirs, as per the product to be tested. The nonreservoir trays were trimmed to one half the clinical crown length, and the reservoir trays were trimmed 1 mm beyond the border of the half‐length reservoir. Measurements were taken from the cementoenamel junction (CEJ) to the tray border for each tooth. The trays averaged 5.1 mm short of the CEJ. The reservoir group was treated with viscous glycerin‐based 10% carbamide peroxide (Opalescence, Ultradent Products Inc., South Jordan, Utah); the nonreservoir group with creamy dentifrice‐based 10% carbamide peroxide (Platinum, Colgate Oral Pharmaceuticals, Canton, Massachusetts). The trays were loaded and fully seated on the teeth. Excess bleaching material was removed with a toothbrush and water rinse. Each assembly was placed in a humidor with incisal edges down to simulate oral conditions. The process was repeated for fourteen 6‐ to 8‐hour bleaching sessions. Blinded and nonblinded operators determined post‐bleaching shades, with consensus reached on differing shades. Results: All teeth demonstrated lightening of 1 to 10 (mean 5.2) increments on the value‐oriented shade guide. The bleaching effect extended beyond the tray and no demarcation lines were noted on any of the teeth. CLINICAL SIGNIFICANCE: This in vitro study suggests that successful bleaching occurs beyond the borders of inadvertently shortened trays. The clinician does not necessarily need to remake the tray if the tray does not cover all portions of the tooth.