Intraoral maxillary molar distalization.
OBJECTIVE
To evaluate the maxillary molar distalization and anchorage loss in two groups, one before (MD 1 group) and one after (MD 2 group) eruption of second maxillary molars.


METHODS
After a sample size calculation, 20 patients were recruited for each group from patients who fulfilled the following criteria: no orthodontic treatment before distal molar movement, Class II molar relationship defined by at least end-to-end molar relationship, space deficiency in the maxilla, and use of an intra-arch NiTi coil appliance with a Nance appliance to provide anchorage. Patients in the MD 1 group were without any erupted second molars during the distalization period, whereas in the MD 2 group both the first and second molars were in occlusion at start of treatment. The main outcome measures to be assessed were: treatment time, ie, time in months to achieve a normal molar relation, distal movement of maxillary first molars, and anterior movement of maxillary incisors (anchorage loss). The mean age in the MD 1 group was 11.4 years; in the MD 2 group, 14.6 years.


RESULTS
The amount of distal movement of the first molars was significantly greater (P < .01) and the anchorage loss was significantly lower (P < .01) in the group with no second molars erupted. The molar distalization time was also significantly shorter (P < .001) in this group, and thus the movement rate was two times higher.


CONCLUSIONS
It is more effective to distalize the first maxillary molars before the second molars have erupted.
Karlsson
Ingela
I
National Health Service, Skane County Council, Orthodontics Clinic, Malmoe, Sweden.
Bondemark
Lars
L
D000293:Adolescent; D002508:Cephalometry; D002648:Child; D003722:Dental Alloys; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008437:Maxilla; D008963:Molar / Q000254:growth & development / Q000503:physiopathology; D009532:Nickel; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D012189:Retrospective Studies; D014025:Titanium; D014078:Tooth Eruption; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome
D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium