Thumb grid / Thumb sucking

Question :


My 7-year-old son sucks his thumb at night since he is very little and he does not seem to be able to get rid of this bad habit.

Both permanent upper incisors have erupted and they are moving forward. My son is even starting to have a little bit of a hard time closing his mouth normally.

I heard about a “thumb grid”.

Is this appliance installed by a dentist or orthodontist? Is it a very expensive appliance?

Réponse :

Thumb grid to break a thumb sucking habit.

I recommend that you consult an orthodontist to evaluate the probable consequences of a prolonged thumb sucking habit.

Indeed, the orthodontist is the most qualified to evaluate the problems associated with a bad finger sucking habit. He will be able to make the best diagnosis on the state of your child’s occlusion or malocclusion and propose good solutions to you.

To know more, I recommend that you read the page “Nonnutritive sucking behavior”.

The enumerated consequences consist of:

1- Increased overjet (the upper teeth are positioned more anteriorly than the lower teeth).

2- Anterior open bite.

3- Elongated arch depth. This is related to the fact that the teeth are positioned more anteriorly (point 1).

4- Narrower upper maxilla.

Case #1

Thumb grid with Hyrax

The intervention that is most indicated is a rapid palatal expansion to correct the insufficient palatal width. At the same time, I take this opportunity to install a small “crib” anteriorly so it is uncomfortable for the patient to place the thumb against the palate.

Thumb grid on EPR AnDub-Dr Chamberland orthodontist in Quebec City

Since the appliance must stay in the mouth permanently for a period of 7 months (about 1 month of enlargement and 6 months of retention), it is enough to break this habit. Moreover, at 7 years of age, the child knows about his problem and is quite happy to see that this appliance helps him get rid of his habit.

The example illustrated above is of a young girl who is 8 years and 4 months of age and who presented consequences of palatal constriction (narrow palate) with a right posterior crossbite and an anterior open bite associated with her bad thumb sucking habit.

The picture in the middle shows the expander once it is enlarged and the anterior grid.

The picture on the right shows that the relationship in width between the upper teeth and the lower teeth is normal. The crossbite is gone. The upper teeth have erupted (come down) and the open bite has improved compared to the initial picture on the left.

The expander was put in the mouth on 4 December 2014. The picture on the right was taken on 11 February 2012, that is a little more than 2 months later.

The young girl stopped sucking her thumb as soon as the first week after the appliance was installed.

Case #2

Passive thumb grid

Tongue grid PaCaPla-Dr Chamberland orthodontist in Quebec City

Here is the case of a young boy who had a bad thumb sucking habit and who had undergone a treatment with a palatal expander at 6 years of age. The young boy had not been able to overcome his bad sucking habit despite the successful correction of his palatal width problem. I had not put a little crib at that time. Whether this was the cause or the young boy was not mature enough, I do not know.

He came back in 2011 and he was determined to break his bad habit. He was then 9 years old and was fully aware of his problem. He did not show any maxillary constriction since it had been corrected 3 years beforehand.

A thumb grid was then made and installed on an archwire and molar bands. Three or four weeks after the thumb grid was installed, I saw the patient again and I noted in his file that he had completely stopped his bad habit. The picture taken in May 2012 (7 months after the appliance was installed) shows the closing of the spaces between the teeth and the covering of the upper teeth over the lower ones, which indicates an increased overbite (closing of the open bite).

The appliance was removed in November 2012, that is 12 months after it was installed. I saw the patient again in April 2015 and he had not restarted his bad habit.


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