Adult Herbst-multibracket appliance treatment-how stable are the results very long term?

To investigate the post-treatment (Tx) changes (≥ 15 years) in adult Class II patients treated with Herbst appliance and subsequently a multibracket appliance (MBA).

Of 51 potential patients 31 could be located and participated (19 II:1 and 12 II:2). At a mean age of 21.8 ± 7.3 years (T0), Herbst-MBA Tx had been started. The mean post-Tx observation period was 19.8 ± 3.6 years. Study models from before and after Tx (T1, mean age: 23.6 ± 7.4 years), after 3.0 ± 2.8 years of retention (T2, mean age: 26.8 ± 8.3 years) as well as after recall (T3, mean age: 43.4 ± 7.5 years) were evaluated using the PAR index as well as standard occlusal variables.

Pre-Tx, the mean values of the 31 participants were: PAR score = 26.1 ± 9.6 points, Class II molar relationship (MR) = 0.7 ± 0.2 cusp widths (CW), overjet = 6.9 ± 2.3 mm and overbite = 4.8 ± 2.6 mm. After Tx, the mean PAR score was 5.3 ± 2.8. A Class I MR (0.0 ± 0.1 CW) was present while overjet and overbite had decreased to 2.1 ± 0.7 and 1.3 ± 0.8 mm, respectively. At recall (19.8 ± 3.6 years post-Tx), a slight PAR score increase (+ 3.1 points) had occurred (final value: 8.4 ± 3.7); this was mainly due to mild increases in overjet, overbite (final values: 3.3 ± 1.4 mm and 2.5 ± 1.7 mm) and changes in sagittal MR (0.2 ± 0.2 CW).

The sample size and the participation rate as well as the unavailability of a comparable control group can be considered as limitations. In addition, no long-term radiographic data could be obtained, and the retention protocol was not uniform. The majority of these issues, however, should be acceptable to due to the duration of the observation period and the uniqueness of the data.

In the present sample, Herbst-MBA Tx enabled Class II correction in adults with very good occlusal long-term stability.