Tag Archives: Expansion

When does midpalatal suture close ?

Summerized by : Dr.Hani Alhebshi.

When does midpalatal suture close ?

Upon searching the web , I found some useful articles answering this question.

It has been stated that there is quite wide variation among individuals that it ossifies at different age groups.

The amount of ossification increases in the growth spurt ( approximately 12-13 years in females , 14-15 years in males) leading to some obliteration at the suture.

There is evidence of continuous ossification in later ages upto 20s (young adults) and even to later age in other studies reaching 32 years! showing marked degree of closure.

The importance of this point lies in whether we can use rapid palatal expansion in adults or not to achieve an opening in the midpalatal suture.Several papers showed clinical cases that palatal sutures were opened in late teens and early twenties.

The following links are of valuable articles I found useful for our discussion.

Here are some important excerpts from these articles.

Continue reading When does midpalatal suture close ?

Nonsurgical RME (Haas) in Adults , is it reliable?

This post is prepared in collaboration with Dr. Maali Faqeeh ..

The results of the following papers indicate that nonsurgical RME in adults is a clinically successful and safe method for correcting transverse maxillary arch deficiency though it was thought to be an unreliable procedure.

1. Nonsurgical Rapid Maxillary Expansion in Adults: Report on 47 Cases Using the Haas Expander.

2. Nonsurgical Rapid Maxillary Alveolar Expansion in Adults: A clinical evaluation.

Does Expansion add a value in absence of crossbite?

Written by : Dr. Waleed Farran ..

The recent trend in orthodontic diagnosis and treatment planning is toward an increasing emphasis on the soft tissue relationship and narrow buccal corridors, accompanied by a declining emphasis on the correction of malocclusion.However, depending of the upper arch as the base diagnostic arch can affect the stability of the orthodontic treatment.

This article discuss if there is no crossbite, did the expansion add a value…..?

Click here to download the article.


Effect of rapid maxillary expansion on the vertical dimension.

Written by : Dr. Rania Alraddadi.

Dear all,

Another topic that we constantly discuss is the effect of rapid maxillary expansion on the vertical dimension.

It was shown that in the long term the  side effects on the vertical dimension are actually minimum.

Here is a systematic review:

http://libdigi.unicamp.br/document/?down=32604 that argues the real long term benefits claimed by bonded RPE users.

According to them, even after the use of bonded RPE, some vertical adverse effects are inevitable. They explained that the vertical change is not caused by buccal tipping of maxillary molars only (which can be controlled by using bonded RPE) but also caused by the whole maxilla being displaced downward. So it was suggested that in cases where vertical dimension is critically sensitive, the use of vertical pull chin cup (or I would also add high pull HG) might be an option.

Explanation of how mandibular expansion follows the Maxillary.

Written by : Dr. Rania Alraddadi .

Dear all,

Today we discussed expansion and mentioned that in most of the cases mandibular arch “follows” the expansion of the maxillary arch and so we rarely use expansion appliances in the mandible.

I just wanted to share the explanation to help the junior residents and refresh the info for the rest of us.

According to Hass, this happens due to several factors:

1- The forces of occlusion were altered by expansion so that the normal lingual vector on the mandibular teeth was lost and the lateral movement of maxilla widened the area of attachment of buccal musculature which caused change in balance between buccal surface and the tongue (a decrease in pressure from the cheeks as result of upper arch expansion will allow the tongue to exert more pressure thus uprighting and expanding lower arch).

2- Thickness of the appliance (3 quarters of an inch) might have caused the tongue to be in a lower position thus exerting even more lingual pressure on mandibular teeth.

Here is the original article:


Thank you.