Influence of conventional and skeletal anchorage system supported fixed functional appliance on maxillo-mandibular complex and temporomandibular joint: A preliminary comparative cone beam computed tomography study

Abstract

Aim: Fixed functional appliance (FFA) used in the treatment of Class II malocclusion, lead to mandibular anterior teeth proclination, thus limiting the skeletal effects of the appliance. To counter this side effect, FFA is anchored in the lower anterior region of the mandible using the skeletal anchorage system. This pilot study was done to evaluate treatment and one-year post-treatment maxillo-mandibular, and temporomandibular joint (TMJ) effects of conventional fixed functional appliance (FFA) and skeletal anchorage system supported fixed functional appliance (SAS-FFA) using cone beam computed tomography (CBCT) images.

Material and method: Sixteen Class II individuals were equally divided into Group I (FFA) (mean age 13.11±0.38 years) and Group II (SAS-FFA) (mean age 12.96±0.38 years). CBCT scans taken, before treatment (T0), at the end of comprehensive treatment (T1), and after one-year post-treatment (T2), were evaluated for changes in maxillo-mandibular complex and TMJ. Intraclass correlation coefficient and independent "t" test were used for repeated measures, and inter-group (mean) changes respectively.

Results: After one-year post-comprehensive treatment, SAS-FFA showed significant maxillary restriction (SNA, -1.93°, P<0.05) with significant increase in mandibular length (Go-Pog, 3.25mm, P<0.001) (Co-Gn, 7.87mm, P<0.001). SAS-FFA groups showed significant upward and backward increase in condylar volume (571 mm³, P<0.001) with anterior translation of glenoid fossa. FFA group showed significant lower dentition and vertical relationship relapse, along with non-significant changes at TMJ.

Conclusion: SAS-FFA is an effective combination, which brings favourable changes on maxillo-mandibular complex and temporomandibular joint with non-significant relapse in comparison to FFA at one-year post-treatment.

Keywords: Ancrage squelettique; Appareil fonctionnel fixe; Articulation temporo-mandibulaire; CBCT; Class II malocclusion; Fixed functional appliance; Malocclusion de Classe II; Skeletal anchorage system; Temporomandibular joint.