Defense Date


Document Type


Degree Name

Master of Science



First Advisor

Thomas Waldrop


AIM: The aim of this investigation is to determine the prevalence of maxillary altered passive eruption in a dental school population. METHODS: 100 subjects were examined clinically and had models fabricated of their maxilla. Demographic, periodontal, cast measurements were recorded for each subject. Demographic variables recorded included age, gender, and ethnicity, history of orthodontic treatment, presence of incisal /occlusal wear, appearance of gingival excess, and presence of gingival asymmetry. Measurements made on cast included clinical crown length, clinical crown width, papillary height, and distance from the lateral gingival zenith to the gingival aesthetic line. Clinical crown width-to-length ratio was calculated. These measurements were compared to previously published standards. RESULTS: 83% of the subjects had central incisors with a clinical W:L ratio greater than .80. Logistical regression analysis determined that subjects with central incisors with an appearance of gingival excess were more likely to have a clinical W:L ratio greater than .80 (P<.0007; OR=79). ANOVA demonstrated that clinical crown length had a statistically significant relationship with gender (P<.0001), tooth type (P<.0001) and biotype (P<0.0026). Clinical crown width and clinical crown W:L ratio had a statistically significant relationship with gender (P<0.0007, P<.0001) and tooth type (P<0.0026, P<.0001). The average clinical crown length was 0.5-1.5 mm shorter than established ideal measurements. CONCLUSION: 83% of the subject population had central incisors that displayed altered passive eruption. Subjects who exceeded the clinical W:L ratio of .80 were more likely to have been classified as having the appearance of gingival excess or “gummy smile”. Esthetic crown lengthening should be considered to achieve desired esthetics in these subjects.


© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

June 2010