Age-related changes in elastic properties and moisture content of lower labial mucosa

Impact of Age and Sex on Electrical Impedance Values in Healthy Oral Mucosa

Background: Electrical impedance (EI) is a property of all living tissues and represents the resistance to the electric current flow through a living tissue. EI depends on the structure and chemical composition of the tissue. The aim of this study was to determine the influence of age, sex, and electrode pressure on the EI values of healthy oral mucosa. The study involved 101 participants with healthy oral mucosa who were divided into three age groups. EI was measured in seven anatomical regions. Results: Significant differences between different age groups were found. Younger participants (20–40 years) had significantly higher EI values than the older participants (60+). Significantly higher EI values were found in women at all localisations at all measured frequencies, except on the hard palate. EI values measured with higher sub-pressure were significantly lower than values measured with lower sub-pressure at all frequencies and localisations, except the tongue dorsum, tongue border, and sublingual mucosa. Conclusions: This study found that EI values in healthy oral mucosa depend on age and sex and may also depend on the pressure of the measuring device. These factors should be kept in mind when EI is used as a diagnostic method for different oral lesions.

Resting salivary flow independently associated with oral malodor

Background

Dryness of the oral cavity is considered one cause of oral malodor. However, it is unclear which of the factors regulating the wetness of the oral cavity are involved in oral malodor development. This study investigated the effects of salivary flow and oral mucosal moisture on oral malodor.

Methods

The study population comprised 119 patients (48 men and 71 women, mean age of 50.6 ± 15.4 years) with complaint of oral malodor. After the oral malodor level had been evaluated by the organoleptic test and gas chromatography, the rates of stimulated saliva and resting saliva and the moisture levels of the tongue and buccal mucosa were measured. The plaque index, bleeding on pocket probing, probing pocket depth, and tongue coating score were also assessed. Strong oral malodor was defined as an organoleptic test score of ≥3.

Results

The flow rate of resting saliva in women was significantly lower than in men. The flow rate of resting saliva and the moisture levels of the tongue and buccal mucosa showed significant negative correlations with age. The flow rate of resting saliva was significantly lower in patients with strong oral malodor than in those with no or weak oral malodor. The flow rate of stimulated saliva and the moisture levels of the tongue and buccal mucosa had no relationship with strong oral malodor. Logistic regression analysis showed that a ≥5-mm probing pocket depth with bleeding on pocket probing, an increased tongue coating score, and decreased resting salivary flow were strong explanatory factors in clinical findings for oral malodor.

Conclusion

This study suggests that the flow rate of resting saliva is a significant modulating factor for oral malodor.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-016-0255-3) contains supplementary material, which is available to authorized users.

The labial aging process: a surface analysis-based three-dimensional evaluation

BACKGROUND

With increasing age, the smile becomes elongated and less appealing. Currently, several methods are proposed for analysis of lip morphology including lateral cephalograms, profile and frontal photographs, video images, and three-dimensional systems. Despite several descriptions of morphologic and histologic age-related changes in the literature, no scientific well-supported model of the labial aging process is reported.

METHODS

For this study, 33 healthy volunteers were selected and divided into two groups according to age: a youthful group (ages 21-34 years) and an aged group (ages 45-65 years). Their dental and labial stone casts were obtained, digitized, and virtually reproduced using a computerized electromechanical digitizer and applying nonuniform rational B-spline geometry. To obtain a synthetic parameter describing local surface deformation, average curvature and curvature variability indexes were computed and compared.

RESULTS

No significant age- or sex-related differences in the average curvature were detected. In contrast, the curvature variability was significantly greater in the young than in the aged subjects.

CONCLUSIONS

The labial arch surface remains macroscopically constant between the third and the sixth decades of life, but with local modifications that influence the standard deviation of its curvature. A high standard deviation described the protruding labial appearance of the young subjects, whereas a reduced one described the flat lips of the aged subjects.

LEVEL OF EVIDENCE IV

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Raman Spectroscopy of Oral Buccal Mucosa: A Study on Age-Related Physiological Changes and Tobacco-Related Pathological Changes

Biophysical techniques play an important role in detecting physiological alterations during pathogenesis. Raman spectroscopy has shown immense potential in identifying several diseased conditions, including oral cancers. Classification of normal, inflammatory, premalignant and malignant conditions has been demonstrated using ex vivo Raman spectroscopy. Feasibility of recording in vivo spectra in clinically implementable time has also been shown. Translation of this technology to clinics requires extensive validation of methodologies, building of robust models and testing the same under stringent conditions as well as on diverse populations. In this context, the ability of Raman spectroscopy in identifying subtle changes in oral mucosa with increasing age, and the influence of these aging related changes on classification with tobacco-related pathological changes was evaluated. A total of 451 spectra from 62 subjects were recorded from buccal mucosa of healthy subjects of 4 different age groups (aged 20–60 years). Also, 478 spectra from 85 subjects belonging to 4 different categories, tobacco exposed mucosa, contralateral normal (opposite side of tumor), premalignant patches and tumors on buccal mucosa were recorded using fiber optic probe-coupled commercial Raman spectrometer. Differences in spectra were explored by unsupervised Principal Component Analysis (PCA) and supervised Linear Discriminant Analysis (LDA), followed by Leave one out cross validation. Results indicate feasibility of classifying early and late age groups. Also, clear classification is observed between healthy and pathological groups, thus inherent heterogeneity in healthy groups seems to have no bearing on classification of normal with abnormal conditions. Findings of the study indicate high sensitivity of Raman spectroscopy in detecting subtle mucosal changes, further supporting efficacy of Raman spectroscopic approaches in oral cancer applications. Prospectively, more vigorous validation studies of Raman methodology would enable routine clinical applications.