Bichat's fat pad: anatomy of the buccal fat pad
- Highlighted area
Quick facts
- Definition
- An encapsulated, deep mass of fat in the cheek, distinct from subcutaneous fat.
- Location
- Between the masseter muscle and the buccinator muscle, with extensions toward the temple and the space behind the maxilla.
- Parts
- A body with three lobes (anterior, intermediate and posterior) and buccal, pterygoid, pterygopalatine and temporal extensions.
- Neighboring structures
- The parotid duct and buccal branches of the facial nerve run along its outer surface.
- Function
- Helps the chewing muscles glide and, in infants, gives the cheek firmness during suckling.
Bichat's fat pad is the buccal fat pad: a deep mass of fat, wrapped in a thin capsule, located between the masseter muscle and the buccinator muscle. It was described by the French anatomist Xavier Bichat in the early 19th century. It is different from the subcutaneous fat of the cheek and has extensions that reach the temple region and the space behind the maxilla.
Where is it and how is it formed?
The most widely used anatomical description divides Bichat's fat pad into a central body and extensions:
| Part | Where it sits | Note |
|---|---|---|
| Anterior lobe | In front, below the zygomatic bone, near the parotid duct | Contributes to cheek volume |
| Intermediate lobe | Between the anterior and posterior lobes | Thinner, highly variable |
| Posterior lobe | Behind, next to the chewing muscles | Gives rise to the extensions |
| Buccal extension | More superficial, in front of the masseter | The part that most influences the contour of the cheek |
| Pterygoid, pterygopalatine and temporal extensions | Deep, toward the temple and the space behind the maxilla | Explain the continuity with the temporal region |
Along its outer surface run the parotid duct, which crosses the buccinator to open into the mouth, and buccal branches of the facial nerve. This proximity is the reason the area is described with caution in any surgical approach.
What is the function of Bichat's fat pad?
It acts as a gliding cushion between the chewing muscles, such as the masseter, and fills deep spaces of the face. In infants it is proportionally large and gives the cheek firmness during suckling. Over a lifetime it tends to descend and reorganize, and its volume varies widely between people, with no direct relationship to body weight.
Why does it matter in facial harmonization?
Bichat's fat pad plays a part in reading the facial contour and the balance between the thirds:
- Full cheeks in youth: part of the volume of the lower face can come from the buccal extension, not only from superficial fat.
- Differential for a wide face: a face that is wide in the lower region can have other causes, such as a well-developed masseter or bone structure. Separating the causes avoids mistaken plans.
- Prior buccal fat removal: removing the buccal extension is a surgical procedure. In patients who have had it, the assessment considers the change in volume and the aging of the area over the years. See does buccal fat removal age the face? and buccal fat removal or harmonization.
How does it show up in the assessment?
- Frontal and three-quarter views: cheek volume below the cheekbone and the transition to the jawline.
- Masseter contraction: asking the patient to clench their teeth helps separate muscle volume from fat volume.
- History: prior buccal fat removal, recent weight loss and volume procedures in the area.
- Relationship with the cheekbone: loss of support in the middle third can accentuate the shadow below the apple of the cheek.
Also called: buccal fat pad, buccal adipose body, Bichat's fat, buccal fat.
Frequently asked questions
What is Bichat's fat pad?
It is the buccal fat pad: a deep, encapsulated mass of fat located between the masseter and the buccinator. It is different from the fat just under the skin and was described by the French anatomist Xavier Bichat.
Does Bichat's fat pad shrink with age?
It tends to descend and change in volume over a lifetime, but the reduction is less marked than in other compartments. The slimmer face of maturity results from the sum of fat, bone and support loss, not from a single compartment.