Twenty-year follow-up of functional treatment with a bionator appliance: A retrospective dental cast analysis

Abstract

Objective: To investigate changes in dental arch configuration, relationship, and malocclusion directly after Class II malocclusion treatment with a Balters bionator modified by Ascher as well as 20 years after treatment. Materials and Methods: Orthodontic dental cast analysis of 18 patients with skeletal Class II treated with a bionator without any additional fixed therapy was performed with a digital caliper at three stages: before (T0), after (T1) and 20 years after (T2) treatment. Arch perimeter and depth, intermolar and intercanine distance, overjet, overbite, sagittal molar and canine relationship, mandibular incisor irregularity (Little's index), and malocclusion (PAR index) were assessed. Results: During treatment (T0–T1), upper arch perimeter significantly increased with a significant decrease in the upper and lower arch perimeter long-term (T1–T2), whereas corresponding arch depths changed only slightly in both periods. Transverse intermolar width increased significantly during treatment, remaining almost constant from T1 to T2. Lower intercanine distance remained fairly unchanged during treatment, but decreased significantly during follow-up. Lower incisor irregularity improved slightly during treatment but increased significantly long-term. After treatment, sagittal molar relationships on both sides were improved, overjet and overbite reduced; these significant changes remained stable long-term. The peer assessment rating (PAR) index was significantly lower after treatment and increased insignificantly during follow-up. Conclusions: 20 years after bionator treatment without additional fixed appliances, the improved sagittal relationship and the reduced overjet and PAR index remained fairly stable. Long-term changes are most likely due to physiological aging processes and are not associated with bionator treatment.

Effects of Bionator Devices on Orofacial Muscle Strength in the Treatment of Class II Malocclusion in Developmental Phase: Systematic Review

“…Orthopedic changes that occur are accelerating the growth of the condyle region, resulting in remodeling of the glenoid fossa and changing the direction of jaw growth [7], [25]. Dentoalveolar changes will produce changes in the sagittal, transverse and vertical directions followed by tipping of the maxillary anterior teeth in a labial direction [26], [27]. A change in the transverse direction causes an expansion of the dental arch, a change in the vertical plane followed by the eruption of a particular tooth.…”

“…In cases of class II malocclusion with mandibular deficiency, functional devices are often used with the aim of stimulating mandibular growth [36]- [38]. Many researchers believe that the main effect of the functional appliance is to increase mandibular growth [6], [26], [39]. Despite some claims that the treatment's most significant effect is limited to dentoalveolar changes because these appliances are toothborne, not skeletal [26], [40].…”

Can Orthodontic Treatment Be Stable 20 Years after the End of the Treatment Scheme? Treatment of a Class 2, Division 1 Malocclusion with Severe Skeletal Discrepancy and Its 20-Year Follow-Up

“…Functional devices such as Sander, Bass, Bionator, and Twin Block by Clark find their use mainly in this type of orthodontic therapy, through more or less similar systems. It is important, however, to keep in mind the therapeutic timing and, as previously expressed, the risk of trauma to the incisors in cases of patients with greatly increased overjets [ 23 ]. This condition is mostly associated with class II, division 1 malocclusion so that early treatment of this condition is often a duty on the part of the clinician, especially when the patients still have with mixed dentition [ 5 , 24 ].…”

Tratamentul miofuncțional și motivația pacientului-caz clinic | [Myofunctional treatment and patient motivation-clinical case]

“…Datorită perioadei lungi de timp necesare pentru realizarea echilibrului funcțional între elementele aparatului dento-maxilar, mulţi pacienţi abandonează. Din acest motiv pot apărea recidive care necesită reluarea tratamentului ortodontic la vârsta adultă (Jungbauer et al, 2020).…”