If the invagination in front of the ear is relatively deep then the term pre-auricular sinus is more appropriate.
A pre-auricular sinus is deeper than a pit and lined with a stratified squamous keratinizing epithelium.
Gentle sounding with a small lacrimal duct probe can be used to establish the depth of the pre-auricular depression and distinguish a pre-auricular pit from a pre-auricular sinus.
Pre-auricular sinuses are usually asymptomatic until they become infected.
The definitive treatment requires a complete excision of the entire sinus tract. Great care must be taken during the excision of a pre-auricular sinus because these sinuses may extend quite deeply and may be closely related to the branches of the facial nerve.