OBJECTIVE: The purpose of this study is to determine the eruption patterns of maxillary and mandibular first molars from the first occlusal contacts to adulthood. Previous studies have failed to obtain measurements into adulthood or have not been longitudinal in design. By using a measurement during the subjects' adulthood, a better estimate of the changes that occur between the tooth and the gingival margin throughout growth and aging can be obtained. METHODS: The material for this research project was obtained from the Meredith Facial Growth Study from the University of Iowa Orthodontics Department. Records from a set of 64 subjects (35 males and 29 females) were used. Each of these patients had intraoral models taken throughout adolescence into adulthood. A final model was available for each subject in their twenties. Twenty-eight subjects had final records available in their forties (14 males and 14 females). Measurements were recorded for the maxillary first molars (Teeth 3 and 14), and the mandibular first molars (Teeth 19 and 30). Measurements were taken at eleven time points for all sixty-four subjects starting at year 8 and yearly until age 18 with a final measurement taken on a model from the patient's twenties. A subset of twenty-eight subjects contained measurements in their forties. Bitewing Radiographs were also used to measure changes in alveolar bone height at 12, 20, and 40. RESULTS AND CONCUSIONS: Alveolar bone heights and their changes over time measured from the CEJ indicate that the sample population had a stable periodontium. Crown heights at age 20 and 40 were significantly greater than age 11. At age 40, crown heights were significantly greater than age 20. Teeth continue to erupt into a patient's forties in the absence of bone loss and attrition.

OBJECTIVE: The purpose of this study is to determine the eruption patterns of maxillary and mandibular central incisors from the first occlusal contacts to adulthood while comparing the differences in male and female eruption patterns. Previous studies have failed to obtain measurements into adulthood. We hope by using a final measurement during a subjects' adulthood we can better estimate final eruption times and measurements. METHODS: The material for this research project was obtained from the Meredith Facial Growth Study from the University of Iowa Orthodontics Department. Records from a set of 64 subjects (35 males and 29 females) were used. Each of these patients had intraoral models taken throughout adolescence into adulthood. A final model was available for each subject in their twenties. Twenty-eight subjects had final records available in their forties (15 males and 13 females). Measurements were recorded for the maxillary central incisors (Teeth 8 and 9), and the mandibular central incisors (Teeth 24 and 25). Measurements points were the incisal edge of the tooth to the most apical (deepest) curvature of the gingival margin. Measurements were taken at eleven time points for all sixty-four subjects starting at year 8 and yearly until age 18 with a final measurement taken on a model from the patient's twenties. A subset of twenty-eight subjects contained measurements in their forties. RESULTS AND CONCUSIONS: Differences between male and female mean crown heights were only present on maxillary incisors at early ages. Tooth 8 at ages 8 to 12 and for tooth 9 at ages 10 to 11. All other ages and all other teeth showed no gender differences. Eruption rates differ for males and female for tooth 8 only. Teeth 9, 24, 25 all showed no differences in their rate of increasing crown height over time. A significant age effect for teeth 8 and 9 and also teeth 24 and 25 in the subset studies was found. There was no significant factor between age and gender. Teeth heights at age 20 and 40 were significantly greater than age 11. At age 40 heights were significantly greater than age 20. Teeth continue to erupt unto a patient's forties.

BACKGROUND: Smile esthetics play a major role in the perception of a person’s attractiveness, as well as other social parameters. The study aim was to see if altering the gingival display of patients would affect perceptions of the aforementioned social parameters. METHODS: Smiling photographs were taken and then digitally altered so as to lengthen the teeth and reduce the amount of gingiva. These photographs were shown to a group of senior dental students, and a group of evaluators with no formal dental training. Groups were asked to rate each picture’s attractiveness, friendliness, trustworthiness, intelligence, and self-confidence. RESULTS: The digitally altered photographs were rated higher for all five social parameters than were their unaltered counterparts (p<0.0001). There were no statistically significant differences between the two groups of evaluators. CONCLUSIONS: Excessive gingival display positively affected how attractive a person’s smile is judged, and also how friendly, trustworthy, intelligent, and self-confident they are.

Prevalence information on excessive gingival display in post-orthodontic patients is limited. By studying one aspect, namely the size relationship of the clinical crowns of teeth, in an orthodontic population, we can begin to quantify their need for periodontal plastic surgery. In this two part study, 200 plaster models were used as subjects, followed by a clinical exam of 31 of those subjects. These models represented patients before and directly after orthodontic therapy, and the Part 2 clinical exams were performed at least five years later. The lengths and widths of the six anterior teeth were measured and these values were compared to known ideals. This study revealed a significant increase in the length of the maxillary anterior teeth over the three examinations, yet these values were still approximately 1.5mm shorter than ideal. The mean tooth width-to-length ratio was 87-88% for maxillary central incisors, clearly below the accepted "ideal." As well, 61-71% of maxillary central incisors exceeded allowable tooth width-to-length ratios, and 61% of subjects displayed asymmetry in gingival architecture. Although this study only examined one aspect of excessive gingival display, it is the first study to show that in a predominantly young, post-orthodontic population, the prevalence of non-ideal width-to-length ratios is greater than 65%, and that the presence of asymmetry is greater than 60%. Therefore, close interaction between the periodontist and the orthodontist is necessary to diagnose these conditions in order to provide patients with all options for improving their smile.

Abstract FACTORS AFFECTING GINGIVAL EXCESS, ALTERED PASSIVE ERUPTION AND RECESSION IN THE MANDIBULAR ANTERIOR AND PREMOLAR SITES By William F Bohlen, D.M.D. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, 2010 Major Director: Thomas Waldrop, DDS, MS Program director, Department of Periodontics, Virginia Commonwealth University AIM: The aim of this study was to determine the factors affecting gingival excess, altered passive eruption and recession. METHODS: 100 subjects were examined clinically and models of their mandible were fabricated. Demographic, periodontal and cast measurements were recorded for each subject. Measurements were made on casts with digital calipers and included clinical crown length, clinical crown width, papillary height and gingival width. The W:L ratio was calculated and the proportion compared to the maxillary arch ideal of .80. Values greater than .80 were used as a cutoff point for defining gingival excess. Measures of periodontal health were also examined and included probing depths, clinical attachment loss and bleeding on probing. Other patient variables examined were history of orthodontics, presence of occlusal and incisal wear, presence of parafunctional habits, subjective appearance of gummy smile and biotype. RESULTS: The mean W:L ratio was found to be 79.6 %. Tooth type (p<0.001), gender (p<0.0237) and biotype (p<0.0081) were found to significantly contribute to a W:L ratio >.80. There was a significant correlation between the subjective appearance of gingival excess and the W:L ratio, regardless of biotype. There was no association between recession and gingival excess. CONCLUSION: Subjectively, 17% of the study subjects had gingival excess. When the author (WB) made the determination that gingival excess was present, there was a significant increase in the W:L ratio for all teeth, regardless of biotype versus teeth without the presence of gingival excess. Proposed ideal W:L ratios for the mandibular anterior teeth from the second premolar to central incisor are listed in Table 11.

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.