The ultrastructure of the gingival epithelium in smokers' melanosis

Effect of Commercial Children's Mouthrinses and Toothpastes on the Viability of Neonatal Human Melanocytes: An In Vitro Study

In this study, we examined the cytotoxic effects of six commercial children's mouthrinses (designated as #1, #2, #3, #4, #5, and #6) and four commercial children's toothpastes (designated as #1, #2, #3, and #4) on primary human neonatal melanocytes that were used as a representative model for oral melanocytes. Mouthrinses diluted directly with culture medium (1:2, 1:5, 1:10, 1:100, and 1:1000) were added to monolayers of melanocytes for 2 min, followed by 24 h recovery, after which MTS cytotoxicity assay was conducted. The extracts of each toothpaste were prepared (50% w/v), diluted in culture medium (1:2, 1:5, 1:10, 1:50, 1:100, and 1:1000), and added to cell monolayers for 2 min (standard brushing time), followed by an analysis of cell viability after 24 h. Results showed that all mouthrinses except mouthrinse #4 showed significantly greater loss of cell viability, ascribed to cetylpyridinium chloride (CPC) that induced significant cytotoxicity to melanocytes (IC50 = 54.33 µM). In the case of toothpastes, the examination of cellular morphology showed that a 2 min exposure to all toothpaste extracts induced a concentration-dependent decline in cell viability, pronounced in toothpaste containing sodium lauryl sulfate (SLS) detergent. Further results suggested SLS to be the critical driver of cytotoxicity (IC50 = 317.73 µM). It is noteworthy that toothpaste #1 exhibited much lower levels of cytotoxicity compared to the other three toothpastes containing SLS. Taken together, these findings suggest that the melanocytotoxicity of children's mouthrinse (#4) and toothpaste (#1) is comparatively low. To the best of our knowledge, this is the first study to examine the impact of children's toothpastes and mouthrinses on neonatal primary human melanocytes. Future studies to investigate these findings in a realistic scenario replicating oral cavity conditions of the presence of microbiota, pellicle layer and saliva, and other cell types are warranted.

Laser Treatment for Melanin Gingival Pigmentations: A Comparison Study for 3 Laser Wavelengths 2780, 940, and 445 nm

The normal appearance of the gingiva is pink to light red, and this appearance may change due to many factors and might be noticeable causing aesthetic concerns. In the Gulf area, the gingival melanin pigmentation is of the main type of concern, and patients expect the pigmentation to be removed for aesthetic reasons. Many techniques have been used to remove the melanin pigmentation such as using surgical blades, diamond or ceramic burs, chemicals, and lasers. This study is comparing the results of three lasers (Er, Cr, YSGG 2780 nm, Diode 940 nm, and 445 nm) in the removal of melanin gingival depigmentation. Clinical outcome parameters including bleeding, wound healing, pain, duration of procedure, color improvement, patient satisfaction, and relapse rate after 2 years were assessed. Conclusion. Within the limitation of this study, all three wavelengths were fast, effective in peeling the pigmentations and well tolerated by the patients. The esthetical results were excellent, and the patients were highly satisfied. Suggestion. To have a bigger number of samples in future papers, and histological studies might be included to explore the different impacts of each wavelength on the gingival melanin pigmentation specifically and on the gingival tissue generally.

A Randomized Comparative Clinical Study to Evaluate the Longevity of Esthetic Results of Gingival Melanin Depigmentation Treatment Using Different Laser Wavelengths (Diode, CO2, and Er:YAG)

Background: Gingival melanin hyperpigmentation is due to excessive deposition of melanin granules. The duration of pigmentation reappearance after treatment using different laser wavelengths remains controversial. Objective: The study aims to assess the longevity of gingival depigmentation (GD) and the consistency in esthetic results as three laser wavelengths (Er:YAG laser, CO₂ laser, and diode laser, 980 nm) were used in two different groups (smokers and nonsmokers). This is attained by comparing the periods of time in each group before pigmentation reappearance. Methods: Seventy-two subjects were divided into daily smokers (S) and nonsmokers. Subjects underwent a randomized GD with: Erbium laser (Er), CO₂ laser (CO₂), and Diode laser (Diode). The subjects were divided into six groups: S and nonsmokers were treated with three different wavelengths. Irradiation was performed until there was no visible pigmentation. For qualitative measurement, Hedin Melanin Index (HMI) was used, before treatment, after 2 weeks, and until 60 months. Pigmentation reappearance of degree 1 or above of the HMI was noted. Descriptive statistics were also calculated. Results: HMI showed a 0 in all groups after 14 days of treatment. The time before pigmentation rebound was: Diode > CO₂ > S-Diode > S-CO₂ > Er > S-Er. The first signs of relapse shown among all groups were seen in the group S-Er group. The longest time before rebound was observed with the Diode group for the nonsmoker. Conclusions: Diode laser provides the longest-term stability in treatment. Smoking negatively affects the longevity of GD. Er laser gives the shortest time before the reappearance of gingival pigmentation.

Clinical and histological evaluation on application of platelet concentrates on depigmented gingival epithelium

Background

The platelet concentrate is a windfall in the field of regenerative therapy in periodontology. It accelerates wound healing by excellent neovascularization and promoting fast cicatricle tissue remodeling.

Aim

This study aims to evaluate clinically and histologically accelerated effect of platelet-rich fibrin (PRF) membrane and PRF matrix (PRFM) following depigmentation procedure.

Materials and Methods

Eleven individuals were divided into three groups after depigmentation procedure. PRF membrane and PRFM gel were prepared as per standard protocol. Group A and B received PRF membrane and PRFM gel followed by periodontal dressing, respectively, and the only periodontal dressing was placed in Group C. The individuals were evaluated for visual analog scale (VAS) and healing index (HI) on 3^rd and 5^th day. Epithelization test and histologic analysis from punch biopsy were done on the 5^th day. At 3^rd month, reevaluation was performed.

Results

The intergroup statistical analysis in respect to VAS, HI, epithelization test, and histologic analysis showed a statistically significant results with P < 0.001 in Groups A and B compared to Group C. Clinical evaluation of epithelization test and histologic analysis revealed better-wound healing and moderate to no inflammatory cell infiltrate in Groups A and B, respectively, as compared to Group C, which appeared more erythematous with dense inflammatory cells.

Conclusion

Thus, the application of PRF membrane and PRFM gel has shown a successful approach to protect the raw wound area of depigmented sites with better patient comfort and faster healing.

Correlation of environmental tobacco smoke to gingival pigmentation and salivary alpha amylase in young adults

OBJECTIVE

Passive smoking leads to melanin pigmentation on gingiva. However, documentation of gingival pigmentation and salivary amylase activity in passive smokers relative to the duration of exposure to environmental tobacco smoke (ETS), is incomplete and requires further investigation. Thus, this study aimed to assess effects of ETS exposure on gingival pigmentation in young adults. In addition, to correlate a number of years of exposure to an extent, the intensity of gingival pigmentation and salivary amylase activity.

MATERIALS AND METHODS

A total of 200 nonsmokers aged 18-35 years with a positive history of ETS exposure were recruited for the study. Duration and source of ETS were assessed using a questionnaire. Gingival pigmentation was assessed using gingival pigmentation index for the extent and Dummett oral pigmentation index for intensity. The skin color of all patients was also assessed. Pearson Chi-square test and one-way ANOVA was used to statistically analyze the data.

RESULTS

Number of years of exposure to passive smoking was highly significant to the extent and intensity of gingival pigmentation (P < 0.001). ETS from home environment was highly significant to the intensity of pigmentation. Environmental sources of ETS contributed to pigmentation as the majority of patients reported exposure from vehicles and workplace. The salivary amylase levels were inversely proportional to the duration of exposure to ETS.

CONCLUSION

Within limitations of this cross-sectional observational study, it was concluded that there was a strong correlation between ETS exposure and gingival pigmentation. Duration of exposure was significant to an extent, the intensity of pigmentation and salivary amylase activity.

Gingival Pigmentation Affected by Smoking among Different Age Groups: A Quantitative Analysis of Gingival Pigmentation Using Clinical Oral Photographs

The presence of any age-related differences in gingival pigmentation associated with smoking, particularly in a young population, remains to be fully investigated. The purpose of this study was to determine the age-related differences in smoking gingival pigmentation. Gingival pigmentation was analyzed using the gingival melanosis record (GMR) and Hedin’s classification with frontal oral photographs taken at 16 dental offices in Japan. Participants were categorized into 10-year age groups, and their baseline photographs were compared. In addition, to evaluate the effect of smoking cessation on gingival pigmentation, subjects were divided into a former smoker group (stopped smoking) and current smoker group. A total of 259 patients 19 to 79 years of age were analyzed. People in their 30s showed the most widespread gingival pigmentation. In addition, subjects in their 20s showed a weak effect of smoking cessation on gingival pigmentation. These findings suggested that the gingival pigmentation induced by smoking was more remarkable in young people than in middle-aged people. This information may be useful for anti-smoking education, especially among young populations with a high affinity for smoking.

The effect of simultaneous exposure of HEMn-DP and HEMn-LP melanocytes to nicotine and UV-radiation on the cell viability and melanogenesis

Nicotine is a main compound of tobacco plants and may affect more than a billion people all over the world that are permanently exposed to nicotine from cigarettes, various forms of smoking cessation therapies, electronic cigarettes or second-hand smoke. It is known that nicotine forms complexes with melanin what may lead to accumulation of this alkaloid in tissues of living organisms containing the pigment. This may affect the viability of cells and process of melanin biosynthesis that takes place in melanocytes. Although UV radiation is known to be a particular inductor of melanin biosynthesis, its simultaneous effect with nicotine on this process as well as the viability of human cells containing melanin have not been assessed so far. The aim of this study was to examine the simultaneous impact of nicotine and UV radiation on viability and melanogenesis in cultured normal human melanocytes dark (HEMn-DP) and light (HEMn-LP) pigmented. Nicotine together with UV radiation induced concentration-dependent loss in melanocytes viability. The higher cell loss was observed in dark pigmented melanocytes in comparison to light pigmented cells. Simultaneous exposure of cells to nicotine and UV radiation also caused changes in melanization process in both tested cell lines. The data suggest that simultaneous exposure of melanocytes to nicotine and UV radiation up-regulates melanogenesis and affects cell viability. Observed processes are more pronounced in dark pigmented cells.

Measurement of Reduced Gingival Melanosis after Smoking Cessation: A Novel Analysis of Gingival Pigmentation Using Clinical Oral Photographs

Background: Due to moisture and the anatomical complexity of the oral mucosa, it is difficult to measure the extent of gingival melanosis in an optical manner. Therefore, we developed a new quantitative method using clinical oral photographs and compared the extent of gingival melanosis before and after smoking cessation. Methods: A new analysis method, which we named the gingival melanosis record (GMR), is a quantitative analysis method using clinical oral photographs. We obtained 659 clinical photographs from 263 patients from 16 general dental offices in Japan. Standardized measuring sites were automatically spotted on the screen, and the presence of gingival melanosis was determined at the measuring sites. We assessed the validity of the GMR with the previously reported Hedin’s classification using Spearman’s rank correlation and intraclass correlation coefficients. Results: The GMR showed a significant association with Hedin’s classification (p < 0.01, correlation coefficient = 0.94). The GMR also showed excellent reproducibility of the substantial repeated agreement intraclass correlation coefficients (ICC) (1,1) and ICC (2,1), p > 0.61). The longitudinal loss of gingival melanosis was confirmed by a change in the GMR among patients who successfully achieved smoking cessation for a mean of 4.5 years. Conclusion: The GMR is an effective method to assess gingival melanosis. The loss of gingival melanosis after smoking cessation can be objectively confirmed with the use of the GMR.

Ancillary role of vitamin C in pink aesthetics

A smile expresses feelings of joy, affection and self-confidence in an individual. Melanin hyperpigmentation of the gingiva jeopardises the aesthetics of an individual significantly. In the present case, gingival depigmentation was performed with a surgical scalpel along with local applications of ascorbic acid, yielding satisfactory aesthetic results with low subjective pain levels, and no recurrence has been observed after 9 months of follow-up.

Nicotine impact on melanogenesis and antioxidant defense system in HEMn-DP melanocytes

Nicotine is a compound of tobacco plants and is responsible for addictive properties of tobacco which is used by about one billion of smokers all over the world. Recently, nicotine has drawn even more attention due to its presumed neuroprotective and antioxidant features as far as common use in various forms of smoking cessation therapies. It is suggested that nicotine may be accumulated in human tissues containing melanin. This may in turn influence biochemical processes in human cells producing melanin. The aim of this study was to examine the impact of nicotine on melanogenesis and antioxidant defense system in cultured normal human melanocytes (HEMn-DP). Nicotine induced concentration-dependent loss in melanocytes viability. The value of EC50 was determined to be 2.52 mM. Nicotine modulated melanin biosynthesis in normal human melanocytes. Significant changes in hydrogen peroxide content and cellular antioxidant enzymes: SOD, CAT, and GPx activities were stated in melanocytes exposed to nicotine, which indicates alterations of antioxidant defense system. The results obtained in vitro may explain a potential influence of nicotine on biochemical processes in melanocytes in vivo during long-term exposition to nicotine.

Split mouth de-epithelization techniques for gingival depigmentation: A case series and review of literature

Gingival melanin pigmentation occurs in all races of mankind. Although clinical melanin pigmentation does neither present itself as a medical problem nor a disease entity, it is a major esthetic concern for many people, especially Asians. Esthetic gingival depigmentation procedures can be performed in such patients with excellent results. This case series presents a split mouth de-epithelization procedure using popular surgical techniques such as scalpel, bur abrasion or electrosurgery. These techniques were successfully used to treat gingival hyperpigmentation. Although we found that electrosurgery increased the efficacy of our work, giving a cleaner and neater work field, it required a lot of precision. In contrast, scalpel de-epithelization was easy and technique-friendly, giving excellent results and patient satisfaction. However, the cases are being followed-up to study the factors affecting the rate and length of time required for repigmentation and to study the repigmentation patterns. This case series also reviews the advantages and disadvantages of various techniques available for depigmentation, and reiterates that the scalpel technique still serves as a gold standard for depigmentation.

The association between Parkinson's disease and melanoma

Parkinson's disease (PD) is a neurodegenerative disorder characterized by a loss of melanin-positive, dopaminergic neurons in the substantia nigra. Although there is convincing epidemiologic evidence of a negative association between PD and most cancers, a notable exception to this is that melanoma, a malignant tumor of melanin-producing cells in skin, occurs with higher-than-expected frequency among subjects with PD and that melanoma patients are more likely to have PD. A clear biological explanation for this epidemiological observation is lacking. Here, we present a comprehensive review of published literature exploring the association between PD and melanoma. On the basis of published findings, we conclude that (i) changes in pigmentation including melanin synthesis and/or melanin synthesis enzymes, such as tyrosinase and tyrosine hydroxylase, play important roles in altered vulnerability for both PD and melanoma; (ii) changes of PD-related genes such as Parkin, LRRK2 and α-synuclein may increase the risk of melanoma; (iii) changes in some low-penetrance genes such as cytochrome p450 debrisoquine hydroxylase locus, glutathione S-transferase M1 and vitamin D receptor could increase the risk for both PD and melanoma and (iv) impaired autophagy in both PD and melanoma could also explain the association between PD and melanoma. Future studies are required to address whether altered pigmentation, PD- or melanoma-related gene changes and/or changes in autophagy function induce oncogenesis or apoptosis. From a clinical point of view, early diagnosis of melanoma in PD patients is critical and can be enhanced by periodic dermatological surveillance, including skin biopsies.

Effects of ascorbic acid on gingival melanin pigmentation in vitro and in vivo

BACKGROUND

Gingival melanin pigmentation may cause esthetic concerns, even if no serious medical problem is present. As an inhibitor of melanin formation, ascorbic acid is often used to treat skin melanin pigmentation. Thus, the present study investigated the effects of ascorbic acid on gingival melanin pigmentation in vitro and in vivo.

METHODS

The effects of ascorbic acid on melanin formation were evaluated in vitro in B16 mouse melanoma cells and three-dimensional human skin models. In addition, a clinical trial was performed to investigate the inhibitory effects of a gel containing ascorbic acid 2-glucoside (AS-G gel) on gingival melanin pigmentation. This study used a double-masked, split-mouth design on 73 subjects with symmetric gingival melanin pigmentation. AS-G gel was applied to one side of the gingiva for 12 weeks, whereas placebo gel was applied to the other side as a control. Luminance (L*)-value, which describes the lightness of gingiva, was determined by spectrophotometry to obtain an objective measure of melanin pigmentation every 4 weeks.

RESULTS

Ascorbic acid significantly inhibited tyrosinase activity and melanin formation in B16 mouse melanoma cells (P <0.01 and P <0.05, respectively). The inhibitory effects of ascorbic acid on melanin formation were also significant in three-dimensional human skin models (P <0.01). Moreover, in the clinical trial, a significant relative change in pigmentation was seen after 4 weeks with the application of AS-G gel compared to placebo (L*-value ratio).

CONCLUSION

Ascorbic acid (AS-G) has potential for the treatment of gingival melanin pigmentation.

Pigmented lesions of the oral mucosa and perioral tissues: a flow-chart for the diagnosis and some recommendations for the management

The term "pigmentation of the oral mucosa" is applied to a wide range of lesions or conditions featuring a change of color of oral tissues. Lesions not associated with an accumulation of pigment (e.g., Fordyce spots) are usually not classified as pigmented lesions. Two groups of pigmented lesions of the oral mucosa are recognized: 1) melanin-associated lesions, including racial pigmentations, melanotic macules, melanocytic nevi, and malignant melanoma; and 2) nonmelanin-associated lesions (e.g., blood-related pigmentations, metallic pigmentations). This paper presents a clinicopathologic review of the recent literature with emphasis on the main diagnostic features, including the use of immunohistochemical markers. A flow-chart is added that may help the clinician in the diagnosis and management of these lesions.

Association of lip pigmentation with smoking and gingival melanin pigmentation

OBJECTIVE

We investigated the association of lip pigmentation with smoking and melanin pigmentation in the gingiva.

DESIGN

Case-control study.

SETTING

Health check-up in an institute.

SUBJECTS AND METHODS

Photos of 213 males employed in an institution were assessed in terms of pigmentation in lip and gingiva.

MAIN OUTCOME MEASURES

Prevalence and scores of lip and gingival pigmentation and smoking status.

RESULTS

Among subjects displaying lip and gingival pigmentation, 73% and 87% respectively, were current smokers, whereas 33% and 27% of individuals lacking pigmentation were current smokers respectively. Odds ratios of current smoking relative to lip and gingival pigmentation were 5.6 (95% confidence interval: 2.8-11.1) and 17.0 (8.1-36.0) respectively. Daily consumption, duration of smoking and lifetime exposure exhibited significant correlation with scores of lip and gingival pigmentation (P<0.0001). Odds ratios increased in lip and gingival pigmentation upon exposure. In current smokers, scores of lip and gingival pigmentation demonstrated meaningful correlation (P<0.0001); moreover, 95% of participants with lip pigmentation were positive for gingival pigmentation.

CONCLUSION

These results indicated the presence of a striking association between smoking and pigmentation in the lip and gingiva, which was stronger with respect to gingival pigmentation. Health professionals could educate smokers, utilizing visible symptoms in the lip and gingiva.

Association of melanin pigmentation in the gingiva of children with parents who smoke

OBJECTIVE

The association between gingival pigmentation and active smoking has been established. This investigation is the first to address the relationship between gingival pigmentation in children and passive smoking.

METHODS

A case-control study was performed involving 59 nonsmoking children who were selected from patient records of a dental clinic in a rural town in Japan. The number of subjects was based on a power calculation. Two calibrated examiners independently observed labial gingiva via oral photographs.

RESULTS

An interview determined that 61% of children had at least 1 smoking parent. Gingival pigmentation was observed in 71% to 78% of children. Interexaminer agreement was satisfactory (kappa = 0.73). Percentage of smoking parents was higher in children with gingival pigmentation (70-71%) than in those who lacked pigmentation (35%). Odds ratios of parental smoking adjusted by age and gender were 5.6 (95% confidence interval: 1.5-20.0) and 5.4 (1.4-21.2) for the 2 examiners.

CONCLUSION

These findings suggest that excessive pigmentation in the gingiva of children is associated with passive smoking. The visible pigmentation effect in gingiva of children could be useful in terms of parental education.

Human oral mucosal melanocytes: a review

Despite the complex role of melanocytes in skin physiology, the function of oral mucosal melanocytes has attracted little research interest and remains largely unclear. This article reviews what is known about oral mucosal melanocytes and identifies areas of research that may shed further light on their role in oral biology.

Disappearance of smoker's melanosis after reducing smoking

Besides genetic factors, tobacco smoking is known to be the main cause of oral melanin pigmentation. The present study compares the frequency of oral melanin pigmentation in a large number of former smokers with that of non-smokers. It also describes in two patients the disappearance of smoker's melanosis in the buccal mucosa following a considerable reduction in smoking.

Melanin depigmentation of the palatal mucosa in reverse smokers: a preliminary study

The melanin pigmentation in the palate of Indian reverse smokers was histologically studied in 80 biopsies, which were compared with corresponding tissue from 49 nontobacco users. The morphology of epithelium containing melanin in its basal part was normal in smokers and nonsmokers, in contrast to areas with a local melanin depigmentation of the epithelium found in some of the reverse smokers. Here an epithelial thinning, inflammation in the underlying connective tissue, and eventually a cancer was found. The histologic appearance was in accordance with the theory that as long as a smoker's melanosis or a genetic melanin pigmentation is present, melanin functions as a defence against toxic agents penetrating into the oral mucosa.

Smoker's melanosis may explain the lower hearing loss and lower frequency of Parkinson's disease found among tobacco smokers--a new hypothesis

A new hypothesis is presented explaining the preventive effect of tobacco smoking found on noise induced hearing loss and on the frequency of Parkinson's disease. The hypothesis is based on the finding of a melanocyte stimulation of tobacco smoking in the human oral mucosa, resulting in a higher melanin content in the epithelial cells, and a higher frequency of visible oral melanin pigmentation--smoker's melanosis. The preventive influence of smoking found in the cochlea and substantia nigra may also be due to a higher melanin content and to the ability of melanin to strongly bind specific chemical agents for a long time. Melanin may in this way act as a scavenger against cell toxic factors in these organs.

Physiologic pigmentation of the oral mucosa in Israeli children

Physiologic melanin pigmentation (racial pigmentation) of the oral mucosa varies in prevalence among different races and ethnic groups. The purpose of this study was to investigate the prevalence of physiologic pigmentation in Israeli Jewish children of different ethnic origins. A total of 1,300 children, 6 to 10 years of age, was examined. Physiologic pigmentation was found in 13.5% of the population studied. Children of Eastern origin showed a significantly higher prevalence of pigmentation compared with Ashkenazi and Sephardic groups. Because melanin pigmentation can be enhanced by mechanical and chemical stimulation (smoking), this study may serve as a baseline for investigation of melanin pigmentation in various ethnic groups.

In vitro activation of amphibian dermal melanocytes by nicotine

Epidemiologic investigations have shown that nicotine could be a factor causing oral melanin pigmentation in man. Nicotine was therefore tested on amphibian skin melanocytes. Cell reactions were registered by spectrophotometry, in vitro light microscopy, photomicrography and light and electron microscopy. It was found that dermal melanocytes in the toad Bufo bufo and the frog Rana arvalis were activated by nicotine and that this activation was not mediated via beta-adrenergic receptors in melanocytes.