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.

Objective To explore the clinical application of FP-PCR method to detect MP-DNA.Methods Five hundred and sixty-three children suspected of MP infection were enrolled in experimental group. FP-PCR was adopted to detect MP-DNA. MP-DNA was re-detected later in 60 children. At the same time,MP-Ab (MP antibody) was detected by means of particle agglutination. MP-Ab was re-detected one or two weeks later. Also 20 healthy children were selected as the control group. Results The positive rate of MP-DNA and MP-Ab were 34. 99% and 35.52% respectively,which showed no significant difference (x2 =0. 31, P > 0. 05). The coincidence of the two methods was 97. 69%. But the positive rate of MP-DNA was significantly higher than that of MP-Ab in the early stage(30. 48% vs 10. 16%) (x2 = 74. 46, P < 0. 05).The sensitivity and specificity of FP-PCR were 96. 00% and 98.62% respectively. The result of reviewed MP-DNA was consistent with the clinical diagnosis. Conclusion FP-PCR method is very sensitive, convenient and stable. It is fit for the clinical application ,especially the diagnosis of early MP infection. It helps to identify those who had been infected with MP before.

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.