Teeth – A Beginner’s Guide…

Toddlers teeth examined by dentist

In my experience as a dentist and father of two girls, teeth and teething are amongst the most common causes of questions and wild speculation I have come across.

In this brief guide I will aim to list a few facts, give a few tips and hopefully demystify why your calm, quiet 10 month old has become a rash covered dribbling bundle of sleepless fury in the last 24 hours.

The basics:

Babies have 20 teeth. These normally erupt in pairs (left and right side within a few days of each other) The first to emerge is usually the lower central incisors, on average these start emerging at 6-10 months old, followed within a couple of months by the upper central incisors. These four teeth meet at the front in the middle of the mouth and set the distance apart which all the other teeth will fit into.

The teeth then emerge over the next year and a half to two years, usually with the lower tooth emerging a couple of months before the corresponding upper tooth. By the time a child is around two and a half years old they should have the full complement of twenty primary teeth (AKA: baby/milk/deciduous teeth). This should comprise (counting back from the centre of the mouth in each quarter) two incisors, one canine and two molar teeth.

You then get three to four years of stability before the wobbles arrive and the deciduous teeth make way for the adult teeth. Again, this starts in the lower jaw in the middle (age 6 and a half, but give or take 18 months, so as early as 5 or as late 8 years old) The 8 incisors should all be replaced over the next 18 months, and the first permanent molar should have emerged at the back, behind the existing baby molars. There is then a pause of around two years before the 12 remaining primary teeth are replaced between 10-12 years old.

The most common question we get asked at this stage is “is it good to wobble?” the answer is definitely yes. If a tooth becomes very mobile, but is not shifted out of the way then the adult tooth can emerge behind the baby tooth and impinge on the space the tongue occupies. This usually causes a sore spot on the tongue. Children are often less keen to brush around wobbly teeth and this can result in plaque build up, and localised gum disease and bleeding. Therefore, entice them to wobble with tales of the tooth fairy and shiny coins for freshly wobbled out teeth!

Hints and tips:

Signs your child may be teething can include an increase in dribbling, disrupted sleep (what’s new?) being tender around the mouth and consequently a diminished appetite as it is uncomfortable to bite and chew. Many parents also comment that bowels become looser and baby is more prone to nappy rash when teeth are emerging. There isn’t a lot of clinical evidence to point towards this, but I’ve heard it said so many times by parents and nursery staff that I think there may be something in it.

Continue to part 2 – Teething Pain Relief


Iain Soulsby BDS, BSc (Hons.)

About the author: Iain Soulsby studied Dentistry and Psychology at Guys Hospital Dental School, University of London. He works at Hayes Dental Surgery in Bromley, South East London (020 8462 1347) www.hayesdentalsurgery.co.uk .

Iain is father to Emily and Charlotte (6 and nearly 2 at the time of writing) He would like more time with his family, more time with his patients and more time to sleep – this isn’t going to be possible.

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