Study Of Holdaway Soft Tissue Analysis On Angle â…¡ Malocclusion Treated By Two-Phase Correction

Objective: To study the effects of two-phase treatment on profile of patients with Angle â…¡ malocclusion.Methods: Fifteen patients of Angle â…¡ malocclusion with mandible deficiency in mixed or early permanent dentition were treated by two-phase correction with Twin-Block as the appliance in the first phase, MBT appliance in the second phase. The effects were evaluated with Holdaway soft tissues analysis and routine cephalometric analysis methods.Results: The results showed that the soft-tissue chin thickness and soft-tissue facial angle increased. the distance of lower lip to H line, H angle, Inferior sulcus depth and skeletal profile convexity decreased. SNB angle increased with ANB angle decreasing, which showed significant difference statistically. The nose prominence, upper lip sulcus depth, soft-tissue subnasale to H line, basic upper-lip thickness and upper-lip strain measurement showed no significant difference statistically. The SNA, U1-SN, U1-NA, L1-MP, L1-NB, U1-L1 angles, Y-axis angle and the mandibular plane angle didn't changed significantly.Conclusion: Two-phase treatment was effective on improvement of facial balance and facial esthetics of Angle â…¡ malocclusion with mandible deficiency in mixed or early permanent dentition. Twin-Block appliance was helpful for the correction of sagittal dental-facial relationship.