Prevalence and Anatomical Distribution of Physiologic Gingival Pigmentation and Its Association With Facial Complexion and Lip Tone in a South Indian Population: A Cross-Sectional Analysis

Gingival pigmentation is a physiologic phenomenon primarily resulting from melanin deposition by melanocytes and demonstrates marked variation across ethnic groups due to genetic, environmental, and evolutionary influences. Despite India's extensive phenotypic diversity, data on the prevalence and anatomic distribution of gingival pigmentation, particularly in South Indian populations, remain limited, even as interest in periodontal esthetics continues to increase.

This cross-sectional study evaluated 100 systemically healthy individuals (54 male and 46 female individuals; mean age 38.31 ± 9.19 years) attending the Outpatient Department of Periodontics at the Amrita School of Dentistry, Kerala, between October 2024 and October 2025. Gingival pigmentation was assessed visually and classified. Lip pigmentation was assessed clinically using a descriptive visual grading based on the extent and intensity of melanin deposition on the vermilion border, and facial complexion was assessed using the Fitzpatrick scale adapted to the von Luschan chromatic scale. Descriptive statistics were used to assess prevalence and distribution patterns, while the Pearson chi-square test evaluated associations between gingival pigmentation and facial complexion, with significance set at p < 0.05.

Class IV gingival pigmentation (moderate dark-hued islands) was the most prevalent pattern (37%), followed by Class VI (severe dark-hued islands, 21%) and Class I (absence of pigmentation, 20%). Facial complexion was predominantly mild brown (60%), and lip tones were most commonly brown (46%) or dark brown (44%). Statistical analysis revealed no significant association between gingival pigmentation and facial complexion (χ² = 13.643, df = 20, p = 0.848). Gender did not demonstrate any discernible influence on pigmentation patterns.

Moderate-to-severe physiologic gingival pigmentation is highly prevalent in South Indian individuals and appears to be independent of facial complexion and gender. These findings challenge assumptions of a direct phenotypic correlation between cutaneous and gingival pigmentation. While the results provide valuable insights for periodontal esthetic management, limitations, including the single-center design and reliance on visual assessment, warrant cautious interpretation. Future multicenter studies incorporating objective assessment tools are recommended to further elucidate gingival pigmentation patterns in diverse populations.