Dental practitioners should interpret responses to electrical pulp testing cautiously in orthodontic patients; thermal testing may be more reliable.

Objective: To investigate the effect of age on the degree of maxillary and mandibular anterior teeth and associated gingival display when the lips are at rest and during smiling among a group of Jordanian population. Methods: A total of 127 subjects (74 females and 53 males) were included in this study. Subjects had all natural anterior teeth present with no caries, restorations, extreme occlusal wear, extrusion, obvious deformities, or tooth mobility. Crown length, displayed portions of maxillary and mandibular anterior teeth and associated gingiva at rest and during smiling were measured using a "Fowler Electronic Digital Calliper", which had a resolution of 0.01mm. The measurements were taken by two independent Dental Clinicians and they were repeated 3 times and the mean value was calculated for further analysis. SPSS (V 11) software was used to analyse the data. Statistical analyses were performed by Student's t-test and ANOVA. Level of significance was set to 0.05. Results: At rest and during smiling; maxillary tooth display decreased, and mandibular tooth display increased with increasing age, but the differences between age groups were not significant, with the exception of the display maxillary central incisor that reduced significantly as age increased (P<0.001). Gingival display during smiling followed a similar pattern and did not present any statistically significant differences between different age groups in the anterior region. However, maxillary gingival display was the highest below the age of 20; and above the age of 60 for the mandibular gingival display, but statistically significant differences were not recorded between age groups. Conclusion: Differences in tooth display in relation to aging should be considered when providing esthetic prosthodontic treatment that involves replacement of anterior teeth.