ABSTRACT
Objective@#Explore the method for volumetric measurement of alveolar bone defect.@*Methods@#This study applied 2 advanced preoperative volume measurement methods: three-dimensional (3D) printing and computer-aided engineering (CAE). Twenty-six unilateral alveolar cleft patients were enrolled in this study from April 2015 to December 2016. Their computed tomographic data were sent to 3D printing and CAE software. A simulated graft was used on the 3D-printed model, and the graft volume was measured by water displacement. The volume calculated by CAE software used mirror-reverses technique.@*Results@#The volume of alveolar bone defect could be detected by both methods. The average volume of the simulated bone grafts by 3D-printed models was 1.61 ml, a little higher than the mean volume of 1.60 ml calculated by CAE software. The difference between the 2 volumes was from -0.34 ml to 0.54 ml. The paired Student t test showed no statistically significant difference between the volumes derived from the 2 methods.@*Conclusions@#This study demonstrated that the volume of alveolar bone defect is about 1.6ml in unilateral alveolar cleft patients aged 9-12 years. The mirror-reversed technique by CAE software is as accurate as the simulated operation on 3D-printed models. These findings further validate the use of 3D printing and CAE technique in alveolar defect repairing.
ABSTRACT
Objective To compare the effect of Q-switch Nd ∶ YAG laser and intensive pulsed light on freckles.Methods 80 patients with freckles were divided into 2 groups randomly.One group of patients were treated with Q-switch Nd ∶ YAG 532 nm frequency-doubled laser,the interval was 8 weeks.The other group of patients were treated with 570 nm intensive pulsed light,the interval was 8 weeks.Results We used Mann-Whitney U test to compare the curative effect of the two groups (P ＜0.05),and the mean rank (34.00) of the Q-switch Nd;YAG laser treatment group was greater than that (47.00) of the intense pulsed light treatment group.Conclusions The curative effect of Q-switch Nd ∶ YAG laser is better than that of intensive pulsed light on freckles.