Background: The tongue exhibits significant individual variability in terms of shape, color, and surface texture. Due to its location, it is easily accessible for medical examination, although often overlooked. This is due to the inadequate number of studies assessing the morphology of the tongue in the healthy population. Determining the range of normalcy allows for the definition of tongue pathology requiring further diagnostics. The aim of this study is to assess differences in the morphological structure of the tongue in healthy individuals based on existing literature. Morphological structure was evaluated in terms of volume, shape, color, coating, papillae, texture, and lingual tonsil.

Materials and methods: PubMed and ResearchGate databases were included for a thorough analysis of morphological differences in tongue structure.

Results: Tongue volume stabilizes by the end of the second decade of life and is closely correlated with BMI. Among the shapes of the tongue, forms such as circular, ellipsoidal, hammer-shaped, in the shape of the letter U, V, or W can be distinguished, and the multitude of these terms results from the lack of a uniform classification. There is agreement regarding tongue color, with various shades of pink and white being the most commonly observed, while the presence of another color may indicate disease. The density and size of individual papillae depend on the region of the tongue, age, and the presence of systemic disease. Geographic tongue, hairy black tongue, and fissured tongue are states of papillae pathology. Fissuring of the tongue increases with age, and fissured tongue is more common in men.

Conclusions: Differences in the morphological structure of the tongue provide significant information about the health status of each individual. It is necessary to be aware of the physiological changes occurring within the tongue for proper diagnosis.