A comparison of gingival display with a requested smile, Duchenne smile, grimace of disgust, and funnel-shaped expression

Digital Workflows in Implant Dentistry Utilizing Intraoperative CT Scanning

Many digital workflows have been utilized in the past few years in the acquisition of implant positions for full arch implant positions intraoperatively and postoperatively. The goal of the different workflows is to offer speed, precision, and predictability. This study outlines the steps for an innovative fully digital full arch workflow that ensures predictable and fast outcomes using digital tools available in most dental implant centers.

Maxillary lip dynamics and gingival display revisited: Utilizing standardized metrics

OBJECTIVE

This study was initiated to validate a predictable system for establishing maximum maxillary lip dynamics and highlight the clinical significance of the findings.

MATERIALS AND METHODS

Seventy-five subjects, ranging in age from 25 to 71 years old were photographed with lips in maximum and minimum reveal. The images were digitally analyzed using set references. The statistical analysis was performed using Meta. Numerics version 4.1.4. A Pearson correlation coefficient (r) was carried out to identify relationships between age and maxillary lip dynamics. A p-value less than or equal to 0.05 was considered to be significant.

RESULTS

A greater percentage of participants have posterior gingival display than anterior gingival display. There is greater movement of the maxillary lip at the cuspid than at the central incisor.

CONCLUSION

There was a tendency for lip dynamics to increase at the right central incisor when there is an increase in lip dynamics at the right cuspid. Lip dynamics does not appear to decrease with age.

CLINICAL SIGNIFICANCE

Accurately recording and considering maximum lip dynamics helps avoid asymmetric, excessive or insufficient gingival architecture, insufficient or excessive tooth length and visible restorative margins.

Dentogingival display through lip border movements: Report of the Committee on Research in Fixed Prosthodontics of the American Academy of Fixed Prosthodontics

STATEMENT OF PROBLEM

Dentists strive to create natural looking teeth for their patients. However, much of the research on esthetic dentistry has used artificial and computer-generated images to establish esthetic norms. Altered images are helpful in determining personal preferences but may be misleading for natural norms.

PURPOSE

The purpose of this report from the Committee on Research in Fixed Prosthodontics of the American Academy of Fixed Prosthodontics was to establish an evidence base for clinical guidelines on lip mobility and the visibility of oral tissues.

MATERIAL AND METHODS

A systematic search was conducted to collect data on the lip border movements and the visibility of teeth and gingiva of human participants.

RESULTS

One thousand and ninety-six articles were processed, and, based on inclusion criteria, 48 articles were reviewed. The findings determined that the upper lip lengthens with age resulting, at rest, in less display of the maxillary teeth and more of the mandibular arch. When evaluating the maxillary incisal edge position at rest, the canines are the most reproducible. Women tend to display more gingiva in a social smile than men, but this may not be so for a true smile of joy. Both the middle and lower facial thirds should be evaluated to detect a maximal smile. Care must be taken not to classify a person incorrectly as having a low smile line because they could still have a potential to show gingiva.

CONCLUSIONS

Evidence-based clinical guidelines are offered to reduce the risk of esthetic failures.

The Influence of Age and Facial Expression (Eye Open/Closed) On Maxillary Dental and Gingival Display

PURPOSE

To assess if there are any differences in maxillary dentogingival exposure between different facial expressions (maximum smile with eyes open and eyes closed), age groups and both sexes.

MATERIAL AND METHODS

Digital photographs of the lower third of the face of 120 subjects, belonging to 6 different age groups were taken. There were 20 subjects in each of the 6 age groups (20-30, 30-40, 40-50, 50-60, 60-70, and 70-80) which were comprised of 80 women and 40 men. Two standardized images of each subject were taken, one of maximum smile with eyes open, and the second of maximum smile with eyes closed. These 240 images were used to quantify a dentogingival exposure ratio (DER) for each tooth spanning the second bicuspids on either side, using standardized measurement techniques. Additionally, incidence of interdental papilla visibility was studied in a binary manner, and all data were studied with respect to various covariables of age, sex and type of facial expression using a generalized linear mixed effects model. A p-value < 0.05 was determined to be statistically significant.

RESULTS

There was a statistically significant difference between the dentogingival exposure ratio (DER) for all images with eyes open and eyes closed per tooth location studied, across all age groups (p ≤ 0.001) and both sexes, suggesting that subject images of smiles with eyes closed had significantly higher dentogingival exposure. There was a decreasing trend of DER with increasing age groups when eyes were open (p = 0.005) and when eyes were closed (p = 0.042), suggesting that older subjects had lower dentogingival exposure. With respect to sex, there was no statistically significant difference in mean DER between males and females, when eyes were open (p = 0.430) and closed (p = 0.351). The incidence of interdental papilla exposure also differed significantly between images with eyes open and eyes closed across all age groups (p ≤ 0.001). However, the incidence of interdental papilla exposure decreased with age, only in images with eyes open (p < 0.001) but was not statistically significant among images with eyes closed (p = 0.127). With respect to sex, there was a significant difference in incidence of interdental papilla exposure in images with eyes open (p = 0.029) but no significant difference when eyes were closed (p = 0.782).

CONCLUSIONS

Maxillary dentogingival exposure decreases with increasing age and is significantly higher when recording maximum smile with eyes closed, for all age groups and both sexes. As this is a simple and clinically reproducible facial expression, incorporating patient's maximum smiling images with eyes closed may be routinely necessary for complete and accurate data collection for prosthodontic treatment planning purposes.

Early event-related potentials to emotional faces differ for adults with autism spectrum disorder and by serotonin transporter genotype

OBJECTIVE

To test differences in neural sensitivity to facial expressions, including expressions with open versus closed mouths, exhibited by (1) adults with autism spectrum disorder (ASD) compared to neurotypical adults, and by (2) short versus long serotonin transporter allele (SLC6A4) carriers.

METHODS

Event related potentials (ERPs) to happy, fearful, and neutral expressions were collected from neurotypical adults (n=25) and adults with ASD (n=27)-of whom 32 had short and 13 had homozygous long SLC6A4 alleles.

RESULTS

In the neurotypical group, we confirmed that the N170, VPP and EPN, but not the P1, were influenced by emotional expressions, and determined the EPN was the earliest component modulated by open mouth. Compared to the neurotypical group, individuals with ASD exhibited differences in EPN amplitude in response to open versus closed mouths and in hemispheric distribution. Across groups, short serotonin transporter allele carriers had reduced P1 amplitude compared to long allele carriers.

CONCLUSIONS

Individuals with ASD exhibited a different pattern of neural response when encoding and recognizing facial expressions at the EPN component. Across groups, SLC6A4 allele type modulated early sensory attention at the P1.

SIGNIFICANCE

These results provide insight into the nature of early responses to emotional information according to genetic variation and clinical condition.