Long-term stability of anterior open-bite treatment by intrusion of maxillary posterior teeth.
BACKGROUND
Anterior open bite results from the combined influences of skeletal, dental, functional, and habitual factors. The long-term stability of anterior open bite corrected with absolute anchorage has not been thoroughly investigated. The purpose of this study was to examine the long-term stability of anterior open-bite correction with intrusion of the maxillary posterior teeth.


METHODS
Nine adults with anterior open bite were treated by intrusion of the maxillary posterior teeth. Lateral cephalographs were taken immediately before and after treatment, 1 year posttreatment, and 3 years posttreatment to evaluate the postintrusion stability of the maxillary posterior teeth.


RESULTS
On average, the maxillary first molars were intruded by 2.39 mm (P<0.01) during treatment and erupted by 0.45 mm (P<0.05) at the 3-year follow-up, for a relapse rate of 22.88%. Eighty percent of the total relapse of the intruded maxillary first molars occurred during the first year of retention. Incisal overbite increased by a mean of 5.56 mm (P<0.001) during treatment and decreased by a mean of 1.20 mm (P<0.05) by the end of the 3-year follow-up period, for a relapse rate of 17.00%. Incisal overbite significantly relapsed during the first year of retention (P<0.05) but did not exhibit significant recurrence between the 1-year and 3-year follow-ups.


CONCLUSIONS
Most relapse occurred during the first year of retention. Thus, it is reasonable to conclude that the application of an appropriate retention method during this period clearly enhances the long-term stability of the treatment.
Baek
Man-Suk
MS
Graduate student, Department of Orthodontics, Oral Science Research Center, Instititute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
Choi
Yoon-Jeong
YJ
Clincial and research assistant professor, Department of Orthodontics, Oral Science Research Center, Instititute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
Yu
Hyung-Seog
HS
Professor, Department of Orthodontics, Oral Science Research Center, Instititute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
Lee
Kee-Joon
KJ
Associate professor, Department of Orthodontics, Oral Science Research Center, Instititute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
Kwak
Jinny
J
Graduate student, Department of Orthodontics, Oral Science Research Center, Instititute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
Park
Young-Chel
YC
Professor, Department of Orthodontics, Oral Science Research Center, Instititute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea. Electronic address: ypark@yuhs.ac.
D000293:Adolescent; D000328:Adult; D001863:Bone Screws; D002508:Cephalometry; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008437:Maxilla; D008963:Molar; D024343:Open Bite / Q000628:therapy*; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D018704:Orthodontic Retainers; D055502:Secondary Prevention; D018709:Statistics, Nonparametric; D014087:Tooth Movement Techniques; D055815:Young Adult