A hairy tongue's length is determined by the elongated filiform papillae, which can measure more than 15 mm in length.
Understanding Hairy Tongue
Hairy tongue, also known as lingua villosa nigra, is a condition where the filiform papillae on the tongue become abnormally long. These papillae are typically tiny, hair-like structures on the surface of the tongue. In a normal tongue, these papillae are about 1 mm long. However, in a hairy tongue, they do not shed as usual and become much longer.
What Makes It 'Hairy'?
The 'hairy' appearance comes from the overgrowth and elongation of these papillae, giving the tongue a furry or hairy look. This is due to a lack of normal desquamation (shedding) of these structures, causing them to grow longer than usual.
Papillae Length Comparison
| Papillae State | Length |
|---|---|
| Normal | Approximately 1 mm |
| Hairy Tongue | More than 15 mm |
Factors Affecting Papillae Growth
- Lack of Normal Desquamation: The primary cause of hairy tongue is the failure of filiform papillae to shed naturally.
- Hypertrophy and Elongation: This condition is characterized by an abnormal increase in the size and length of these papillae.
Practical Insight
The length of the filiform papillae is a key distinguishing factor between a normal tongue and a hairy tongue. While a healthy tongue has short papillae, a hairy tongue has papillae that have extended far beyond their normal length, often reaching over 15 mm.
