In your patients in Phase 1 treatment–or ages six through nine–fixing midlines depends on a couple of different circumstances. As always, you should view each case as an individual. Each patient has a different skeleton, different teeth, and different case details.

In this article, we’ll discuss what factors dictate whether or not it is possible to fix midlines in Phase 1 and when to know that you should not attempt it.


Is It Possible to Correct Dental and Skeletal Midlines in Phase 1 Treatment?

The etiology of the midline shift deviation, which midline is off, and why the midline shift has occurred are all major factors in determining when the best time to correct a midline is. For example, if you have a case where the upper midline is off due to the early loss of a baby tooth, the pulling of a tooth early, etc., you could likely fix the midline in Phase 1.

However, if the upper midline shifted due to a skeletal midline deviation, Phase 1 would not be the time to try to correct the midline. It’s possible that this issue could be improved in Phase 2, but these midlines might not ever get properly fixed. So, it’s important to remember that some issues persist due to the skeleton formation.

For lower midline shifts, you should check to see if there is a unilateral or bilateral crossbite, deviations, asymmetries in the face, or a CRCO shift. There could be interferences, such as a baby tooth or a tall filling. Getting rid of the interference could fix the issue.

All in all, knowing the etiology of the midline issue is the key to knowing what can be fixed in Phase 1 versus what is better left for Phase 2. The goal of Phase 1, after all, is to fix the bite, ensure there is enough room for future teeth to come in, and to make sure there is a perfect vertical.