EXTRACTION ORTHODONTICS: A PRECURSOR TO TMD?
It has been my experience that a lot of extraction orthodontic patients have TMD symptoms ranging from mild headache 1-2 times a week to full-blown, all-day everyday headaches and other symptoms. Extraction orthodontic technique requires the removal of 2 bi-cuspids on each arch. It is often called “4-bi” extraction technique (i.e. 2 bi-cuspids on the top arch, 2 bi-cuspids on the bottom arch).
Dental schools only train their students to keep the bite the same.
The main reason for teeth to grow in crooked is usually due to lack of space. The average extra space that must be created in order to make all teeth in the arch straight is 4 mm. The average width of a bi-cuspid is 6 mm. Extraction of 2 bi-cuspids in the maxilla will result in 12 mm. But since only 4 mm is needed for the alignment of the teeth, there is 8 mm of space left over from the extractions. The left over space is then closed using closing techniques (i.e. power chain, closing springs, etc...). Pulling teeth together to close the space will result in a smaller and narrower maxilla. Now the mandible must occlude into a maxilla that is narrower than before. It usually has to move posteriorly to make that happen. The end result is a retruded mandible.