Tooth and Gingival Display in the Anterior Region at Rest and during Smiling of Different Age Groups : A Comparative Study

Abstract

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.

Association of the nasolabial angle and lip length with the gingival and interdental smile line—A gender based evaluation

“…The difference of LL at rest and on smiling was however found to be more in females than the males indicating a fuller smile exhibited by the females. These findings of difference in LL are similar to the ones reported by Al‐Habahbeh et al 7 where the authors reported a lip elevation of 5.2 mm and 23% decrease in LL, though the segregation based on gender was not reported. In another study by Miron H et al 9 the maxillary lip at rest was found to be 3 mm shorter in females than the males and the authors attributed the differences to the simple biologic scaling clearly indicating sexual dimorphism.…”

“…The amount of tooth visibility is definitively determined by the muscle position at rest whereas during smiling it is ascertained by dynamic muscular position of the lips 4,5 . So essentially, the degree of tooth display in the maxillary anterior region at rest position and while smiling is dependent on positions of the maxillary and mandibular lips 6,7 …”

The Interference of Age and Gender on Smile Characterization Analyzed on Six Parameters: A Clinical-Photographic Pilot Study

“…Correia et al [ 12 ] evaluated the intercommissural distance, proposing that changes in this variable could explain the exposure of lower teeth in elders, suggesting that changes in the muscle tone might interfere with this distance. Al-Habahbeh et al [ 40 ] and Dindaroğlu et al [ 20 ] reported an inversion in the exposition of teeth, with a decrease for the upper teeth and an increase in the lower teeth exposition with aging. This event can be caused by the loss of lip elasticity, lower migration of the surrounding soft tissues, and the wear of the anterior teeth causing their shortening [ 22 , 23 ].…”

Average 3D Skeletofacial Model as a Template for Maxillomandibular Repositioning During Virtual Orthognathic Surgical Planning

“…Some cross-sectional studies have suggested that the mean value of incisal show at rest should be 2 to 3 mm and could be differentiated between male and female individuals, different races, and different lip shapes. [59][60][61] Therefore, our average three-dimensional skeletofacial models require some modifications to approximate the size of the frontal and orbital areas, which entails rotating the template to mimic a patient's skeletal pattern. Moreover, clinical evaluation is still required after simulations using the average threedimensional skeletofacial models.…”