Asymmetric Extractions

[mikey]

Has anybody here has a single upper extraction or three extractions (one upper and two lower)?

I've recently been to five consultations for some upper and lower crowding, and a class II bite on the left (with a class I on the right). One orthodontist recommended non-extraction, two recommended one extraction, one recommended three extractions, and one recommend four extractions. This is all documented here:

viewtopic.php?t=10747

In looking into the treatment options I was recommended, I found the linked document interesting.:

http://www.jco-online.com/archive/artic ... clenum=573

The author, Dr. Sadowsky, has done research on cases where patients are Class II (overjet) on one side only, and Class I (ideal) on the other. He writes to contest some published claims in the Journal of Clinical Orthodontics from June 1996. Here is one particularly interesting part (my interpretation with translation of the terms is first, followed by his original wording):

My Interpretation:

He takes issue with the suggestion that extracting a tooth only on one-side, in cases where the patient is Class II on only one-side, is something that "few patients willingly accept and few orthodontists enthusiastically recommend". Now, in the case where the treatment is the extraction of a single upper molar on the class II side (such as the treatment the 2nd and 4th orthodontists recommended to me), he agrees that it is unusual. However, although unusual, it may be appropriate if the upper back teeth are too far forward (which may occur due to losing baby-teeth too soon).

However, he argues that the "asymmetric" extraction of three teeth (such as suggested by the 1st orthodontist to me), where two upper bicuspids (one from each side) and a lower bicuspid on the Class I side are extracted, is very appropriate, assuming that the lower jaw is crowded and asymmetric (where one side is shifted more forward than the other). This is because you maintain the Class I (optimum) bite on the side that had it to begin with, and bring the canines on the Class II side into a Class I relationship (plus you align the midlines).

If the patient is Class II on only one side because the teeth in the lower jaw are asymmetrically aligned, doing anything other than asymmetric extractions is going to result in the upper or lower teeth not being symmetric (when viewed from the front). If you try non-extraction therapy (as recommended by the 3rd orthodontist to me), for example because of a flat profile, lack of crowding, or lack of protrusion (i.e., the teeth don't stick out forward), you may not be able align the bite well.

Original wording:

"As a final point, I also take issue with The Editor's Corner by Dr. Larry White in the same issue, in which he suggests that unilateral extraction in Class II subdivision therapy is a therapy "few patients willingly accept and few orthodontists enthusiastically recommend". If Dr. White is referring to the unilateral extraction of a maxillary premolar on the Class II side, I agree it is an unusual solution--although occasionally appropriate if the maxillary posterior teeth are mesial on the Class II side, usually due to premature loss of primary teeth. I contend, however, that asymmetric extraction (two maxillary premolars and a mandibular premolar on the Class I side) is a very appropriate strategy for these cases when there is crowding and dentoalveolar asymmetry in the mandibular arch. Such treatment results in a symmetrical lower arch, with a Class I molar and canine relationship on the Class I side, a Class II molar and Class I canine relationship on the Class II side, and the midlines coincident. If the Class II subdivision is due to mandibular dentoalveolar asymmetry (in the anteroposterior plane), then any other treatment requires a compromise between a symmetrical maxillary dentition and an asymmetric mandibular dentition. In cases where extractions are not indicated--as with a flat profile, absence of crowding, or absence of dental protrusion--a compromise in the occlusal relationships may be necessary."

[missingu]

In all honesty, I really couldn't follow what the article was talking about. My understanding is that each arch is treated "individually" to a certain extent, as the issues are completely different on the two, so there is no reason to unilaterally say that extractions should be symmetric in the first place.

I am scheduled to have one extraction, lower only. Symmetry never entered my mind.

I'd shy away from 4 extractions, as at least some of the opinions think that treatment could work with significantly fewer. However, it is important to decide on the ortho based on the sense you got for how communicative they were, knoweldgeable, etc.