The effectiveness and long-term stability of overbite correction with incisor intrusion mechanics.
BACKGROUND
Correction of deep overbite with subsequent achievement of long-term stability is difficult. The purpose of this study was to investigate the effectiveness and long-term stability of overbite correction with incisor intrusion mechanics.


METHODS
The treated group consisted of 25 subjects (13 female, 12 male) with deep overbite of at least 4 mm (mean overbite, 5.9 mm). The orthodontic treatment was initiated in the late mixed or early permanent dentition, and all patients were treated nonextraction. All patients had lateral cephalometric radiographs taken at pretreatment (T1), posttreatment (T2), and postretention (T3). The treatment included cervical headgear and lever arches to intrude mainly the maxillary incisors and occasionally the mandibular incisors. Premolars were not included in the fixed appliances during the treatment. The untreated group consisted of 25 age- and sex-matched subjects from the Bolton Growth Study.


RESULTS
The mechanics used were effective in overbite correction. During the posttreatment period, overbite increased by 0.7 mm.


CONCLUSIONS
Although this change was statistically significant, the amount was small and is considered clinically insignificant, given the severity of the overbite pretreatment. Furthermore, a net overbite correction (T3-T1) of 3.3 mm and postretention overbite on 2.6 mm is an excellent clinical outcome.
Al-Buraiki
Huda
H
Department of Orthodontics, University of Illinois at Chicago, 60612, USA.
Sadowsky
Cyril
C
Schneider
Bernard
B
D002508:Cephalometry; D002648:Child; D005260:Female; D006801:Humans; D007180:Incisor; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D008437:Maxilla; D012189:Retrospective Studies; D055502:Secondary Prevention; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods; D014716:Vertical Dimension