Question 1

Why do we have wisdom teeth if they cause so many problems?

Accepted Answer

Because our **jaws changed faster than our teeth did**, and the mismatch is recent in evolutionary terms.

**What they are.** The third molars, usually erupting between 17 and 25 — the origin of the name, arriving at an age associated with maturity. They are the last teeth to develop.

**Why our ancestors needed them.** Early human diets consisted of raw, tough, fibrous plant material, raw meat, and food containing grit from grinding stones. That required substantial chewing force and surface area, and it wore teeth down heavily — by adulthood, molars could be significantly abraded, so a third set arriving late replaced lost grinding capacity.

Ancestral jaws were also **larger and longer**, with room for all 32 teeth.

**What changed:**

**Cooking**, which softens food dramatically and reduces the chewing required. This is the leading explanation, and it began hundreds of thousands of years ago.

**Food processing** — grinding, pounding, and eventually agriculture and soft modern diets.

**Reduced mechanical loading during growth.** Jaw size is not purely genetic; **chewing stress during childhood influences how much the jaw develops**. Comparisons between populations eating tough traditional diets and those eating soft processed ones find measurable differences in dental crowding, which suggests part of the problem is developmental rather than inherited.

The jaw shortened; the tooth-development programme did not shorten with it.

**Why they cause trouble.** With insufficient room, they become **impacted** — trapped against the tooth in front or angled through bone. That causes pain, infection (**pericoronitis**), decay in the adjacent molar, and cyst formation.

**They are also unusually variable.** Some people have all four, some have none at all, and rates of absence differ substantially between populations — consistent with a structure under relaxed selection.

**Removal is not automatic.** Current guidance in the UK, from NICE, advises against removing asymptomatic impacted wisdom teeth, reversing earlier routine extraction.

Question 2

Why does stress cause physical symptoms?

Accepted Answer

Because the stress response is a whole-body physiological state evolved for physical emergencies, and running it continuously produces real effects in tissues that have nothing to do with

Question 3

Why must you fast before an operation?

Accepted Answer

To reduce the risk of aspiration — stomach contents entering the lungs while you are unconscious — which is uncommon and can be very serious when it happens. The mechanism. Awake, you have protective

Question 4

Why does hearing decline with age?

Accepted Answer

Mostly because the hair cells in the inner ear are damaged over a lifetime and do not regenerate in humans — a cumulative, largely irreversible loss that begins far earlier than most people realise.

Question 5

Why is back pain treated so differently now?

Accepted Answer

Because the evidence changed substantially, and the old model — rest, scan, find the damage, fix it — turned out to make outcomes worse for the great majority of cases. What is now understood: Most

Question 6

What is osteoporosis, and who should be assessed for it?

Accepted Answer

A condition in which bones lose density and structural quality, becoming fragile enough to break from a fall or force that would not normally cause a fracture — and its defining feature is that it is

Question 7

Why do some people need glasses?

Accepted Answer

Because the eye's optics and its length do not match — light is brought to a focus in front of the retina, behind it, or unevenly, and a lens corrects the mismatch. How focusing works. Light is bent

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