Dentoskeletal Effects of Aesthetic and Conventional Twin Block Appliances in the Treatment of Skeletal Class II Malocclusion: A Randomized Controlled Trial

Abstract This clinical trial evaluate the skeletal and dentoalveolar changes resulting from a modified twin block (aesthetic twin block) (ATB) in comparison with conventional twin block (CTB). Two-arm parallel group randomized clinical trial was performed at Department of Orthodontics, University of Damascus, Syria. Fifty-two patients (33 females and 19 males) aged 12.23±0.77 years with skeletal class II division 1 malocclusion caused by mandibular retrognathism. The participants were randomly assigned to a study group according to a simple randomization method using a numbered and sealed envelope. The experimental group were treated with aesthetic twin block, and control group were treated with conventional twin block. Sixteen angular variables and eleven linear variables (measured in millimeters) were evaluated before the treatment (T0) and at the end of the active phase of the treatment (T1) on lateral cephalometric radiographs to study the skeletal and dentoalveolar changes. There was a statistically significant change in ANB angle between the ATB group (-2.70±0.84) and the CTB group (-1.92±0.81°) (P = 0·002), and SNB angle the ATB group (2.72±1.54°) and the CTB group (1.72±1.41°)(P = 0·02). The Jarabak ratio decreased significantly in the CTB group by (-0.65±1.37%) (P = 0.02) and increased significantly in the ATB group by (0.84±1.44%) (P =0.007), with significant differences between the two groups (P = 0.000). The change in upper incisor angulation was (0.36±5.91°) for the ATB group and (-3.5±4.18°) for the CTB group, which was statistically significant (P = 0·01). The change in lower incisor angulation was (1.34±2.08°) for the ATB group and 3.88±2.47° for the CTB group, which was statistically significant (P = 0·000). ATB had greater skeletal effectswith more control of vertical growth, and greater control of lower and upper incisor angulation. Trial Registration: (NCT05418413) (14/06/2022).