The purpose of this study was to evaluate the skeletal and dentoalveolar effects and optimal timing for treatment of class II malocclusion with functional appliances in children and adolescents. A group of 30 patients with class II malocclusion were divided into 3 groups according to their use of functional appliance: Twin block, Activator, Fränkel appliance. The group was also divided into 2 groups according to the cervical vertebrae maturation method. Lateral cephalometric radiographs were analyzed pretreatment (T0) and osttreatment(T1). Among the functional appliances, treatment with Twin block and Activator showed significant increase in the length of the mandible (Co-Gn) and the lower anterior facial height (ANS to Me), whereas the overjet and overbite were significantly reduced. Treatment with Fränkel appliance showed significant improvement in the relationship of maxilla and mandible. In addition, if the functional appliance was used during the period of pubertal growth peak, there was a significant increase in mandibular length, improvement in the relationship of maxilla and mandible, labial inclination of lower incisors and decrease in overjet compared to the treatment before pubertal growth peak. Therefore, this studyindicates that using functional appliances for patients with class II malocclusion is effective and the optimal timing for using functional appliances is during pubertal growth peak.

Objective: The optimum chest compression point during cardiopulmonary resuscitation (CPR) associated with a good neurological outcome is unestablished. We aimed to suggest the association between the point and a simple index measured on anteroposterior chest radiography (chest_AP). Methods: This retrospective, cross-sectional study included all adults with available chest_AP who arrived at a university hospital from January 2014 to June 2019 for non-traumatic out-of-hospital cardiac arrest (OHCA). Distances from the vertical midsternum to the farthest right and left cardiac borders were defined as RB and LB, respectively. Their sum provided cardiac diameter (CD). Assuming the universality of cardiac anatomy, the cardiac structure immediately beneath the midsternum was compressed most forcefully during CPR. The influencing outcome of CPR was determined using the RB:CD ratio. We investigated the association of RB:CD ratio with a good neurological outcome at discharge using multiple logistic regression analysis, adjusting for the core Utstein elements and comorbidities. Results: Among 429 patients (63.2±14.5 years; 121 [28.2%] female), return of spontaneous circulation, survival-to-discharge and good neurological outcome at discharge were achieved in 259 (60.4%), 121 (28.2%) and 84 (19.6%) cases, respectively. The RB:CD ratio (0.279±0.072) was divided into semi-tertiles to enhance clinical usage: <0.25 (n=149, reference), 0.25-0.30 (n=119) and >0.30 (n=161). The second group was associated with good neurological outcome (odds ratio, 6.00 [95% confidence interval, 1.58-22.8], P=0.010). Conclusion An RB:CD ratio of 0.25-0.30 measured on chest_AP is associated with good neurological outcomes in OHCA victims receiving CPR.