OBJECTIVE: To investigate the amount and pattern of changes of maxillary front teeth 7 years postretention, which previously were retained with a bonded retainer. MATERIALS AND METHODS: The study group consisted of 27 patients. Study models before treatment (T1), at debonding (T2), 1 year after removal of the upper bonded retainer (T3), and 7 years postretention (T4) were present. The irregularity index (sum of contact point displacements) and the rotations of front teeth toward the raphe line were calculated. RESULTS: The irregularity index of the maxillary front teeth changes very little or not at all during the first year postretention. Further change long term resulted in an irregularity index of mean 2.0 (range 0.0-5.8). The contact relationship between the laterals and centrals seems to be the most critical. Forty rotated teeth in 21 patients were corrected more than 20 degrees . Mean relapse during the first year postretention was 6.7 degrees (range 0.0 degrees -14.7 degrees ). Mean changes during 7 years was 8.2 degrees (range 0.0 degrees -19.3 degrees ). CONCLUSIONS: Relapse of upper front teeth retained with a bonded retainer is minor in both the short and long term. If permanent retention is required after 3 years of retention, it is enough to retain the incisors.
OBJECTIVE: To investigate the amount and pattern of changes of maxillary front teeth 7 years postretention, which previously were retained with a bonded retainer. MATERIALS AND METHODS: The study group consisted of 27 patients. Study models before treatment (T1), at debonding (T2), 1 year after removal of the upper bonded retainer (T3), and 7 years postretention (T4) were present. The irregularity index (sum of contact point displacements) and the rotations of front teeth toward the raphe line were calculated. RESULTS: The irregularity index of the maxillary front teeth changes very little or not at all during the first year postretention. Further change long term resulted in an irregularity index of mean 2.0 (range 0.0-5.8). The contact relationship between the laterals and centrals seems to be the most critical. Forty rotated teeth in 21 patients were corrected more than 20 degrees . Mean relapse during the first year postretention was 6.7 degrees (range 0.0 degrees -14.7 degrees ). Mean changes during 7 years was 8.2 degrees (range 0.0 degrees -19.3 degrees ). CONCLUSIONS: Relapse of upper front teeth retained with a bonded retainer is minor in both the short and long term. If permanent retention is required after 3 years of retention, it is enough to retain the incisors.
Authors: Jonathan Perry Ormiston; Greg J Huang; Robert M Little; Jay D Decker; Geoffrey D Seuk Journal: Am J Orthod Dentofacial Orthop Date: 2005-11 Impact factor: 2.650