Tooth Grinding – The Quiet Dental Disorder
The reason we call it ‘quiet’ is that it is rarely diagnosed by dentists and rarely observed by the patient experiencing it (unless that sleeping partner tells him or her). However, it is remarkably common, certainly in our stressed out culture and society.
So why is it important, aside from waking other people up?
Bruxism is a (para) functional activity that occurs subconsciously at night when the individual is asleep. He or she grinds their teeth against each other by moving the lower jaw sideways with the teeth in hard contact. The pressures exerted by the jaw muscles during this subconscious state during sleep are far greater than people normally apply in a normal waking state.
Dental enamel is a very hard material (a bit like ivory). However, when it rubs against itself it will wear down . It is like rubbing two diamonds against each other.
- The human dentition develops with the different teeth having different functions:
- The upper front incisors are shovel shaped ( like rabbits) and are designed for ‘cutting’.
- The side canine teeth come through with pointy tips ( like in cats and dogs) are designed for ‘tearing’.
- The side/ back premolar and molar teeth are block shaped with flat surfaces ( as in cows and horses) and are designed for chewing and crunching.
- However in humans, the canine teeth have a very important additional function: they protect all the other teeth, particularly the front ones (incisors), from contact during sideways movement . As the lower jaw moves sideways, with the teeth ‘in contact’ (as they are in night time grinders) , the upper and lower canines ride up onto each other’s points and in doing so, ‘separate ‘ all the other teeth….. so they do not touch.
In the case of bruxers, these canine tips wear each other down until the canines flatten out. By that time, other teeth, particularly the upper and lower front incisors start to rub against each other. The result is that these teeth start to chip at their edges , wear down at an accelerated rate and so become shorter and shorter . In other words… this is a ‘self-destructive’ habit ! Tooth enamel will NOT grow back even if the habit ceases. So the net result is a loss of tooth enamel until the softer underlying tooth dentine material is exposed and that wears even faster.
As this happens ‘over time’ the appearance of very flat, short teeth with uneven or perhaps, chipped edges and the biting surfaces all in a straight line is very ageing!
Why are some people habitual bruxers and some not?
We don’t really know for sure. Many causes have been implied (a bad bite, missing teeth, stress itself, sleeping disorders etc). There is a strong suspicion that there may be a significant genetic predisposition with many people (i.e. a relative in the family, father, mother, grandparent) also has the habit. Certainly stress, irrespective of whether it is work or personal, acts a ‘trigger’ in those individuals that have the predisposition. I certainly see a lot of City based patients of all ages and that includes people in their 20s, who show signs of excessive tooth wear; and many of these people are in high pressure jobs.
The real problem is ‘recognising’ this disorder in that it occurs over a period of time , it is usually painless and people don’t notice the visual, physical changes to the teeth (simply because they do happen gradually). Occasionally a severe bruxer may experience tension , soreness or tightness of the ‘chewing’ muscles upon waking… because these muscles have been ‘running a marathon’ during the night (damaging the teeth as they do it).
Most of the old ‘common ‘ dental diseases are well known, curable and preventable: decay and gum disease . Excessive tooth wear is very often ‘missed’ and so progresses unwittingly until it actually becomes quite extreme, usually in middle age but often even in early adulthood. Recognised early it can be prevented; recognised late – it can be treated!
How to recognise bruxism in yourself and what can be done?
- Are your front tooth edges chipped or wearing down unevenly?
- Do you think the teeth are shorter than they were when you were a late teenager or young adult?
- Are the canines ( particularly the upper ones) flat and have ‘lost’ their pointy tips ? When you consciously grind sideways ( with your teeth gently ‘in contact) , do the upper and lower front teeth touch each other?
Many dentists, if they recognise the signs of bruxing will simply inform the patients and tell them that they can make them a plastic night-time mouth guard, so the patients grinds enamel to plastic instead of enamel to enamel. There is one major problem with this therapy: as tooth grinding is painless, very few people want to go to bed with what is essentially a denture (over their teeth). It is not exactly that comfortable and let alone ‘sexy’. So the mouth guard doesn’t do much good when it is gathering dust on the bedside table.
The logical alternative, going back to the function of those canine teeth …. is to replace the worn down canine tips (in a tooth colour matched material) and so restore their protective function. That deals with the functional problem and will stop it from getting worse. If so much wear has already occurred that there is an aesthetic problem that the patient wishes to correct, then usually some form of veneering of the short, worn teeth is indicated to restore their length and so … their ‘youth’.[ssba]