ASK THE DOC

Surgeon and lecturer Dr Sarah Rayne weighs in on wisdom teeth (or the lack thereof), how often you should use nasal spray and why there’s no need to fear carpal tunnel surgery.

Q: My husband can’t remember having had his wisdom teeth removed. Is it possible that he was evolved enough not to produce them (which is what he chooses to believe)?

A: If you were hoping to prove your husband wrong, I have some bad news… We are born with all the teeth we will ever grow, situated above or below the jaw, waiting to grow in. As we grow, our 20 milk teeth are replaced with 32 permanent teeth; the last to develop are our three sets of back teeth (molars).

In prehistoric days, before we cooked meat and were able to cut veggies into chewable pieces, we had small brains and big jaws to grind and chew. Nowadays we need only two sets of molars, and if the last set (the wisdom teeth) does develop, they may not fit into our smaller mouths, causing painful impaction with infections. More than 80 percent of people will need to have them removed, but interestingly, one in 10 people don’t develop them at all.

So if your husband chooses to believe he’s evolved beyond wisdom teeth – he may well be right! Q: My doctor told me I could use the nasal spray she prescribed for a maximum of five days – why is that?

A: The average nose produces about 1 litre of mucus every day! Most of it is swallowed, but if there is an irritation, more is produced, leaving you with a blocked or runny nose. You could have a cold or flu, or it could be because of allergies, particularly at this time of year.

Nasal decongestant sprays can really help with this, but I agree with your doctor that they should not be used for more than a few days. This is because they reduce the blood flow to the passage of the nose, stopping the swelling and the mucus. If these areas get used to this over many weeks, they may respond by becoming even more active when you stop using the spray. This causes more congestion and symptoms, which creates a vicious cycle of needing more spray.

So yes, you do need to limit your use of decongestant sprays to less than five days at a time. If you find you need them more than a few times a year, ask your doctor about other treatments. Q: I’ve bad carpal tunnel syndrome in my left hand – it wakes me up at night, and in the morning my hand is completely numb. But I’m really scared of surgery. Can I learn to live with it, or are there other consequences?

A: All the nerves of the hand pass through a tunnel of bones and fascia at the wrist. If there is swelling in the tunnel it causes the nerves to stop working, resulting in pain or numbness. Because the affected nerve (the median nerve) supplies the thumb and thumb-side of the hand, you won’t have numbness in the little finger. (If you do, this is not carpal tunnel syndrome).

This tends to happen in pregnancy (everything swells in pregnancy!) and to people with diabetes, hypothyroidism and arthritis. The symptoms can be worse at night because of the way we sleep.

During the surgical procedure, the fascia is cut so that the swelling stops pressing on the nerve. Surgery tends to be reserved for cases where the muscles have become weak or numbness is constant. If you can still shake out the numbness easily, wrist splints at night will help avoid pressure on the nerve, and a steroid injection in the wrist can also reduce the swelling.

Discuss these measures with your doctor as alternatives, but I would trust them if they think surgery is the best option – it will help prevent long-term damage to the nerve. The operation is often done under local anaesthetic and through keyhole techniques, so there’s nothing to be afraid of.