22 June 2023

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Effect of quality of orthodontic finishing on the stability of anterior tooth alignment

Davide Elsido

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Several factors might be associated with the stability of anterior alignment after orthodontic treatment. 

Maintenance of the arch form has been related to better posttreatment stability. Intercanine and intermolar widths tend to decrease in the post retention period, especially if dental arches were expanded during treatment. The presence of third molars is routinely blamed for posttreatment tooth alignment changes, although there is no scientific evidence to support a causal relationship. There is some evidence that retention is the only approach capable of maintaining long-term stability. Nevertheless, some experts argue that quality of finishing could contribute to alignment stability and advocate that prolonged use of a retainer may be unnecessary in cases with excellent alignment. The influence of the quality of finishing on stability has been poorly investigated.

Anterior esthetics is of great importance for patients, and tooth alignment produced by orthodontic treatment has a significant effect on quality of life. Hence, predicting alignment stability based on the quality of anterior alignment is relevant to the decision to maintain orthodontic retainers. 

A study published in The Angle Orthodontist in May 2023 aimed to evaluate whether the quality of orthodontic finishing influenced the long-term stability of anterior tooth alignment.

Researchers evaluated 38 patients in this retrospective study. Data were obtained at the beginning of treatment (T0), at the end (T1) and at least five years after T1 (T2). At this point, the individuals were no longer wearing retainers. The effect on alignment stability was tested with multiple linear regression.

Results

At T2, the alignment stability in the upper arch was inversely associated with the alignment quality and directly associated with overbite at T1. Posttreatment changes caused cases finished with poor alignment to become similar to those finished with excellent alignment. In the mandible, posttreatment changes were directly associated only with Overjet and well-finished cases displayed better alignment than poorly finished cases. Other variables showed no significant association.

Conclusions

In arches without retention, better quality of orthodontic finishing does not guarantee the stability of anterior alignment. In the maxilla, long-term changes were more significant the greater the overbite and the better the quality of alignment at end of treatment. In the mandible, changes were not dependent on the quality of finishing but were associated with greater overbite at T2.

Paulo Mecenas, Paula Coutinho Cardoso, Nair Galvão Maia, Francisco Ajalmar Maia, David Normando; "Effect of the quality of orthodontic finishing on the stability of anterior tooth alignment." Angle Orthod 2023; doi: https://doi.org/10.2319/101722-722.1.