Know Your Mouth

Resource

Free oral-health diagrams

Original diagrams drawn for this site’s articles, free for practices, educators and writers to reuse. One condition: credit us visibly, with a link.

By ·Updated 23 September 2026

Every article here gets a diagram drawn for it rather than a stock illustration bought in. They are plain vector drawings, built to explain one mechanism each — what a toothbrush cannot reach, how long plaque stays removable, where the gum used to sit.

Anyone who has looked for a usable dental illustration knows the problem: the good ones are expensive, the free ones are ugly or licensed so restrictively you cannot put them in a handout. So these are yours, under a licence that actually permits the uses people need.

The licence, in plain words

These diagrams are original work by Know Your Mouth, licensed under Creative Commons Attribution 4.0 (CC BY 4.0). You may reuse, adapt and republish them — including in commercial settings like a practice website or a patient handout — provided you credit “Know Your Mouth” with a visible link to knowyourmouth.com.

For print use, where a link is not possible, the text credit alone is fine.

The credit line, ready to copy:

Diagram: Know Your Mouth (knowyourmouth.com), CC BY 4.0

How to take one

Every diagram below is inline SVG, not an image file — which means it stays sharp at any size and you can recolour it. Right-click and save the image, or view this page’s source and copy the <svg> block straight out. No sign-up, no email, no download gate.

Adapt them if you need to. Changing the labels, the colours or the language is fine and expected — the licence permits it, and a diagram that fits your handout is more useful than one that doesn’t.

Gums

Where the bone goes Original bone level Healthy Gingivitis Reversible Periodontitis Permanent Pocket
Gum disease: healthy, gingivitis, periodontitis
The gum inflames first and recovers. Once the bone behind it retreats, that loss is permanent.
From gum disease signs
What recession exposes Enamel — crown only Where the gum used to sit Exposed root, no enamel Gum today Bone
What gum recession exposes
The gum used to sit exactly where the enamel ends; everything below that line is root.
From receding gums causes

Breath

Why it is the tongue Papillae Trapped debris Sulphur compounds Tongue surface
Why bad breath starts on the tongue
Papillae on the back of the tongue create sheltered, oxygen-poor crevices where odour-producing bacteria live.
From bad breath causes

Teeth

From clean to permanent Minutes Clean Hours Film forms 1–2 days Soft — brushable 2–3 days+ Hardened — dentist only Minerals from saliva turn it to stone
Plaque to tartar, in about 48 hours
Plaque is soft and removable for roughly two days; then saliva minerals set it hard.
From plaque vs tartar
What a brush cannot reach Brush reaches Contact point Sheltered, oxygen-poor Brush reaches
What a toothbrush cannot reach
Bristles ride over the outside of both teeth and never enter the contact point between them.
From how often should you floss
Two entirely different jobs Stain removal Sits on top Bleaching Goes inside
Stain removal versus bleaching
Surface stain sits on the enamel; only peroxide penetrates it and changes the tooth's own colour.
From natural teeth whitening
Two ways a sensitivity toothpaste works Cold air or touch a b Exposed surface Dentine tubules Pulp · nerve a Calm the nerve Potassium salts Fluid still moves; the nerve answers less b Plug the tubule openings Stannous fluoride, arginine, bioactive glass, strontium, hydroxyapatite Diagram: Know Your Mouth · knowyourmouth.com · CC BY 4.0
Two ways a sensitivity toothpaste works
Potassium calms the nerve and leaves the tubules open; the other actives plug the tubule openings so less fluid moves.
From toothpaste for sensitive teeth
Hydrogen peroxide in the box, by where you buy it Strips in safety trials ~6% EU · UK, via a dentist, 18+ up to 6% EU · UK, sold in shops 0.1% maximum 0% 2% 4% 6% hydrogen peroxide, present or released Diagram: Know Your Mouth · knowyourmouth.com · CC BY 4.0
Hydrogen peroxide in the box
Strips in published safety trials carried about 6%; EU and UK shop kits are capped at 0.1%, with up to 6% only through a dentist.
From do whitening strips damage your enamel?

The oral microbiome

A tooth, in cross-section Enamel Dentine Pulp — nerve, blood Gum Bone Plaque biofilm Root
A tooth in cross-section
Enamel covers only the crown. Below the gumline the root has no enamel at all.
From oral microbiome
Territory, not warfare Occupied Open Room to move in
Occupied versus open tooth surface
Resident bacteria hold territory. A stripped surface is an opportunity, not a protected one.
From do oral probiotics work

Supplement labels

What the panel tells you Supplement Facts Serving size 1 soft tablet Servings per container 30 Amount per serving Proprietary probiotic blend (3.5 billion CFU***) 20 mg L. paracasei L. reuteri B. lactis BL-04 *** 3.5 bn CFU at time of manufacture Other ingredients Tricalcium phosphate, peppermint… Disclosed and specific Serving size · strain designation (one strain of three) Disclosed but pooled 3.5 bn CFU, one figure across three organisms Not stated Per-strain split CFU at expiry Strain codes for two of three
What a probiotic panel tells you, and what it does not
A stylised supplement facts panel. Serving size and one strain designation are specific; the CFU figure is pooled across three organisms; the per-strain split, the count at expiry and two strain identities are not stated.
From what the ProDentim label actually says
Where a reference list thins out Example figures, not an audit 14 references on the page 9 with a DOI or PubMed ID 5 in a peer-reviewed journal 2 Support the claim they sit under Counted Checkable Published Read The tool gets you to the third band. Only reading gets you to the fourth.
Where a reference list thins out
Fourteen citations, nine with an identifier, five in a journal, two that support the claim. Illustrative figures: each band is a question the one above cannot answer.
From the reference checker

Between the teeth

Where each one reaches A · String floss 1–2 mm Contact point Below the gum margin B · Water jet Contact stays shut The col and the margin Trials measure bleeding at the margin, not decay at the contact.
Where floss and a water jet each reach
Floss passes the contact point and runs one to two millimetres under the gum margin; a water jet clears the trough between the teeth and the margin, but the contact stays shut.
From do water flossers actually work?

A note on what these are

These are teaching diagrams, drawn to make a mechanism legible. They are schematic rather than anatomically exact — proportions are adjusted for clarity, and colour is used to mean something (calm rose for healthy tissue, coral for inflamed) rather than to match life. Use them to explain an idea, not to identify a condition.

If you use one, we would genuinely like to see it — hello@knowyourmouth.com. Not required by the licence, just nice.