me and my eldest son have 2 each on each sid of our tongues.they are very sore, l keep catching mine on my back teeth. how can we get rid of them?

l get mouth ulcers quite often, just as u say sometimes on the tongue by rolling around on a sharp bit of tooth etc ..

Anyway, l use ADCORTYL in ORABASE for mouth ulcers, available over the counter at Boots for about a fiver, very effective & loads better than Bonjela which l find does nothing.

It is a paste & sets slightly so is best used at Bedtime as u should not eat or drink immediately after putting it on, but if put on the ulcer early it stops it from getting any larger & can eradicate the ulcer in a day.

http://chemistdirect.co.uk/adcortyl-in-orabase-for-mouth-ulcers_1_10491.html

Have you both eaten something particularly sharp or bitter? l often get them if l have eaten something particularly acidic.
Good oral hygiene is essential. Use a mouthwash and also buy some Bonjela or sore mouth ulcer gel as that will ease your pain.

Mouth ulcers are caused due to many reasons some of them are damage to the inside lining of your mouth by very hot or acidic food and drink,accidental biting of the cheek, injury from a toothbrush or lacking certain vitamins and minerals in your body such as folic acid and B-group vitamins or iron and it may also caused due to lot of stress also.

Yes, rough edge on tooth and sometimes an over reaction of the immune system or a lack of vit B12.
Stress can be a predisposing factor.
Occasionally an infection causes them, but in this case there are other symptoms in the body.