Buccal Corridor

Buccal corridor refers to the dark space (negative space) visible during smile formation between the corners of the mouth and the cheek-side surfaces of the upper teeth.

Its appearance is influenced by:

1. the width of the smile and the upper arch.
2. the tone of the facial muscles.
3. the positioning of the labial surfaces of the upper premolars.
4. the prominence of the canines, particularly toward the back of the tooth.
5. any discrepancy between the value (brightness) of the premolars and the six front teeth.

Arch form has a direct influence on the buccal corridor. The ideal arch is broad and conforms to a U shape. A narrow arch is generally unattractive. It disrupts the principles of golden proportion and makes the centrals appear far too dominant. Patients with very narrow arches may require orthodontics and possibly surgical intervention prior to restoration in order to achieve excellent results. The unattractive, negative space should be kept to a minimum. This problem can be solved or minimized by restoring the premolars. The buccal corridor should not be eliminated completely because a hint of negative space imparts to the smile a suggestion of depth.

The negative space is often accentuated when only the six upper front teeth are restored. The improvements in hue and value of these newly restored teeth often exaggerates the sense of depth, darkness and prominence of the buccal corridor. Because of this concern, it is advisable in some cosmetic cases to include the premolars in the restorative plan.