| Background: Little et al performed a long-term stability study of cases with four premolar extractions 10 and 20 years post-retention. It was found that less than 30% have a satisfactory anterior occlusion, regardless of how well the case finished. About 30% of the general population has an anterior tooth-size discrepancy, yet no stability studies have been conducted on these types of cases.;Purpose: This study aimed to assess the long-term stability of cases with an untreated anterior tooth-size discrepancy.;Methods: We evaluated the existing cases from the original long-term stability study and separated them into two groups: no anterior tooth-size discrepancy and anterior tooth-size discrepancy. The included cases were measured with digital calipers accurate to 0.01 mm for intercanine width, intermolar width, arch length, overjet, overbite, the Irregularity Index, and seven ABO cast grading criteria at 3 time points: pre-treatment (T1), post-treatment (T2), and post-retention (T3). The measurements were averaged and compared within themselves and between groups.;Results: Cases with anterior tooth-size discrepancy at T2 had worse occlusal relationship, higher Irregularity Index, and the alignment was not as good as those without an anterior tooth-size discrepancy. Most of the differences between the two groups disappeared by T3. The exception was the occlusal relationship and occlusal contact measurements, which stayed significantly worse for the anterior tooth-size discrepancy group.;Conclusion: According to the occlusal relationship measurement, it appears more difficult to fit the teeth together ideally in those with an anterior tooth-size discrepancy, and this does not self-correct over time. In most other factors, an anterior tooth-size discrepancy does not greatly affect long-term stability. |
