Factors associated with orthodontic stability: a retrospective study of 209 patients.
OBJECTIVE
To assess the long-term stability of orthodontic treatment and some factors associated to posttreatment changes.


METHODS
Six hundred twenty-seven dental casts of 209 patients were examined with the PAR Index at pretreatment (T1), end of treatment (T2), and at long-term follow-up (T3, mean 8.5 years posttreatment). Friedman test and multiple regression analysis at P < .05 were used to evaluate changes among the time points and factors associated with stability.


RESULTS
After orthodontic treatment, the PAR Index improved by 94.2%. No significant change was observed between T2 and T3 (P>.05). However, when the sample was divided into a well- (PAR Index ≠ 3) and a less well-finished (PAR Index >3) group, it was observed that well-finished patients experienced some deterioration (P<.001), whereas the less well-finished ones showed some improvement (P<.05). Even with the deterioration, the well-finished patients still had a better PAR Index at T3 compared to the less well-finished ones. Regression analysis showed that PAR Index at T1 and T2, age at T1, and length of retainer wear had a slight association with occlusal stability (R(2)=0.27). No significant association was observed between stability and length of treatment, length of follow-up, sex, extraction, or third molar status on the other side.


CONCLUSIONS
Orthodontic treatment is quite stable. Not so well-finished treatments tend to show some improvement and well-finished ones deteriorate some. Well-finished patients still have better occlusal characteristics. Retention contributes to maintenance of the final orthodontic results.
Maia
Nair Galvão
NG
Federal University of Rio Grade do Norte, Brazil.
Normando
Antonio David Corrêa
AD
Maia
Francisco Ajalmar
FA
Ferreira
Maria Angêla Fernandes
MA
Alves
Maria Socorro Costa Feitosa
MS
D000293:Adolescent; D000367:Age Factors; D003766:Dental Occlusion; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008311:Malocclusion, Angle Class I / Q000628:therapy; D008312:Malocclusion, Angle Class II / Q000628:therapy; D008964:Molar, Third / Q000473:pathology; D018704:Orthodontic Retainers; D009971:Orthodontics, Corrective / Q000706:statistics & numerical data; D057887:Overbite / Q000628:therapy; D012008:Recurrence; D012189:Retrospective Studies; D012737:Sex Factors; D014081:Tooth Extraction / Q000706:statistics & numerical data; D016896:Treatment Outcome; D055815:Young Adult