Oral mucosa

Why this matters

Almost everything you will ever look at in a mouth is mucosa, and almost every decision you make touches it. Where it is bound to bone you cannot infiltrate comfortably, cannot raise a split flap and cannot stretch it. Where it is loose and non-keratinised it tears under a retractor, absorbs a sublingual tablet in minutes, and carries the surfaces you only see if you lift the tongue. It also generates most of a new clinician's false alarms: leukoedema, linea alba and physiological pigmentation are normal findings that look like disease.

The big picture

One epithelium, one basal layer, one upward differentiation programme - run at different settings in different postcodes of the same mouth. The type predicts behaviour under load; the site decides the detail; and almost every number attached to oral mucosa turns out to be a number plus a reference point plus an instrument.

The 15 cards in this lesson

1. 01The three mucosal types are a functional map, not a measured category
2. 02Every region has an address, and the addresses are what the classification is about
3. 03Three in-vivo studies give three different thicknesses for the same cheek
4. 04Keratinisation is a differentiation programme, not a coating applied on top
5. 05Four surfaces, four different answers to what sits at the top
6. 06Lining mucosa is permeable because its lipid is disorganised, not because it has no keratin
7. 07The col is non-keratinised, invisible, and the reason interdental sites break down first
8. 08Healthy gingiva in one photograph - including pigmentation that is normal
9. 09The mucogingival junction is a colour, texture and mobility boundary that you locate by a method
10. 10The paper behind the 2 mm rule concluded the opposite, and three later studies disagree with it
11. 11A thickness is a number plus a reference point plus an instrument
12. 12A mucocutaneous junction is where appendages stop and the keratin set changes
13. 13Clinical alert — in the lesson
14. 14Three normal findings that get referred as white patches
15. 15How much of the mouth is keratinised? The two published counts cannot both be right

You have got it when

You can name the three mucosal types and say why the scheme is a functional map rather than a measured category; state where a submucosa is absent and what the lamina propria binds to in each place; find the mucogingival junction and say what iodine is actually reporting; state what Lang and Loe's study measured and what it concluded; explain why lining mucosa is permeable without saying the word keratin; and…