The Effects of Early Biobloc Treatment on Hyperdivergent Children

Abstract

To evaluate the skeletal and dental changes produced when treating hyperdivergent children in the mixed dentition with BioBloc appliances.

The study sample included 46 (16 M, 30 F) consecutively treated hyperdivergent subjects 8.2 ± 1.1 years of age at initial records. Each subject was treated with Biobloc therapy alone, which consisted of 3 phases and used 4 appliances to expand the maxillary and mandibular arches and retrain the oral posture. The expansion phase, orthopedic phase, and the 1-year retention phase lasted 4.3 ± 1.7 years. A matched, untreated control group was used to evaluate treatment effects. Lateral cephalograms were taken at the start of treatment and at the end of the retention phase to determine dental and skeletal changes.

The treated group showed significant (p<.05) AP maxillomandibular corrections compared to untreated controls, resulting in a 7x greater (1.9°) reduction of the ANB angle. Pogonion and menton advanced 2.3x (3.3 mm) and 1.9x (2.6 mm) more in the treated than control group, respectively, and SNB increased 4x (1.3°) more than the controls. Treatment produced a greater 4.2 mm class II molar correction, largely due to mandibular advancement. Overjet reductions of 1.5 mm were observed in the treated group, compared to 0.6 mm increases in the controls. The gonial angle decreased significantly less (1.5°) in the treated than the control group. The Y-axis showed that mandibular growth of the treated group changed toward a more horizontal direction. Vertically, treatment produced no statistically significant skeletal or dental between-group differences. No significant changes were observed in hyoid position or hyoid angle.

This preliminary study showed that Biobloc therapy produces significant improvements of AP maxillomandibular skeletal and dental relationships through anterior mandibular displacement, and changes toward a more horizontal direction of mandibular growth.