Scalp, face and facial expression

Why this matters

The face is the part of the body a dentist injects, incises, examines and watches move — and the part where you are most likely to be the first clinician to see a facial palsy or a spreading infection. It is also the only region where muscles end in skin rather than bone, which is why it can express anything and why its swellings and creases can be read.

The big picture

Facial muscles insert into skin, so the face moves as a sheet anchored along lines. Where skin is tethered a crease forms and fluid stops; where it is free a pocket forms and fluid collects. Read creases and the edges of swellings and the face tells you which plane a problem is in and which way it will travel.

The 14 cards in this lesson

1. 01Muscles that end in skin
2. 02SCALP: five layers, two consequences
3. 03Creases are lines; swellings have edges
4. 04A lost fold is a readout, not a diagnosis
5. 05Three apertures and one knot
6. 06The buccinator decides where the pus goes
7. 07Clinical alert — in the lesson
8. 08One trunk, five territories
9. 09Read the face before you touch it
10. 10Clinical alert — in the lesson
11. 11Central, peripheral, or your anaesthetic?
12. 12Three bands, three foramina, two exceptions
13. 13Two carotid systems meet in the face
14. 14Clinical alert — in the lesson

You have got it when

You are ready when you can tell an upper from a lower motor neurone facial palsy across a waiting room, say why a scalp laceration gapes, and name the two routes by which a facial infection reaches the cavernous sinus.