Objective To discuss the effects of implants of different thread face angles on the primary stability of immediately loaded implant using the 3-dimensional finite element analysis with the models of the immediately loaded implants. Methods Using the commercial code of Pro/E software, Hypermesh software, and ABAQUS software we created 3-dimensional finite element models. The micromotions of the finite element models with different screw face angles (V-shape, buttress, square-shape and inverse buttress) were computed with the ABAQUS software. Results Concerning different thread face angles, the micromotion of buttress implant was the minimum and the micromotion of inverse buttress implant was the maximum with vertically loading; the micromotion of inverse buttress implant was the minimum and the micromotion of buttress implant was the maximum with horizontal loading. Conclusions Different screw-types have great influence on vertical interfacial micromotions but little influence on horizontal interfacial micromotions. There are two angles which are formed by top /bottom edge and the implants. The larger are the angles, the smaller are the vertical interfacial micromotions, but the weaker of the strength. Thus in designing the screw-type implants, we should consider the angles of thread faces and the strength.

Objective To study the clinical efficacy of bilateral double Z plasties for correction of the webbed neck defects, and to explore its principle and superiority to other reported methods. Methods We designed a small Z plasty over the mastoid with a rhomboidal skin resection of infra-hairline, and another large Z plasty transposition skin flap in superior-acromion. The tight band of fibrous webbing was separately cut and undermined at infra-mastoid and midclavicular line, wherein the middle part of the band retracted medially.Results It involved narrow tunneled anterolateral skin undermining and minimal skin resections from the nape of the neck, and posterior rhomboidal skin excision avoided the unnatural and noticeable lateral scars with normal skin extended in the middle of the webbing.The resultant scar was hidden and mild with no hypertrophic scars. A total of 5 cases were repaired, in which 1 case was male, 4 others were females. Follow-up for 1 to 11 years showed that the appearance and function in the repaired sites by using the bilateral double Z-plasties for repair of webbed neck deformity were very satisfactory. Conclusion We propose the use of this technique for correction of webbed neck deformities with simplified manipulation and cosmetic effect.

Objective To study the MTHFR gene (677 gene loci and 1298 gene loci) mutations in Chinese patients with keloid. Methods The tissue DNA was extracted from 20 samples of keloids. and peripheral blood samples from the same patients were employed as the control. Polymerase chain reaction(PCR) was used to amplify the Mthfr 677 gene loci and Mthfr 1298 gene loci from the keloid tissue DNA and peripheral blood DNA. and the PCR products were sequenced directly and then compared with the GenBank data. Results Mutations were detected in 17 out of 20 keloids on Mthfr 677 gene loci, the mutation incidence was 85.0 %. Mutations were detected in 13 out of 20 keloids on Mthfr 1298 gene loci, and the mutation incidence was 65.0 %. The mutation involved point mutation, deletion and insetion as well as multisite and multitype. No MTHFR gene mutation was detected in all peripheral blood samples . Conclusion There is a strong correlation between the MTHFR gene (677 gene loci and 1298 gene loci) mutation and keloid.

Objective To explore the synchronous cosmetic surgical procedures for the beauty-seekers who have both single eyelid and commonly horizontal cockeye in order to acheive either time saving or beautifying. Methods Firstly, the distance of moving backwards and shortening length of the eye muscle were calculated and designed according to the degree of cockeye; secondly, the height of the double eyelids line and positioning were re-designed; then the moving backwards and shortening of the horizontal macula were put up to rectify the cockeye; finally, the incisal double eyelid operation was performed. Results All 25 patients with inner cockeyes were corrected at the right position; 4 of 11 patients with outer cockeyes were corrected 5～10 degrees over the right position, and others were at the right position. The single eyelid with thin-eyelid and middle-thick-eyelid restored within 3 months; but the patient with thick-eyelid restored slowly, about half a year in average. 2 patients with redundant skin at inner corner of eye were also corrected at the right position. Conclusions Although there is somewhat difficulty in the plastic surgery for patients with cockeye and single eyelids, synchronous operation can save time and outlay, and also acheive the aim of beautifying. Therefore, it is a good approach to deal with cockeye.

Objective To summarize the data of cosmetics dermatosis happened in Bering in 2006 and to analyze their characteristics of this side effect.Methors The outpatients in the Department of Dermatology.Air Force General Hospital from Jun.2006 to Dec.2006 were investigated and screened out the cosmetic dermatosis according to GB17149.1～7-1997,the patients'age,gender,job and the demographic data and the suspected cosmetics were recorded and analyzed,and the routine patch tests using the involved cosmetic products were carried out in each patient.Results 327 cases of cosmetic dermatosis were reported.Among all cases.98.47% of the patients were female,and most of them aged between 21 and 40 years old:The suspected cosmetics included 47 brands with 618 imposed products,43 brands with 293 domestic and the joint venture products,and 14 illegal products;Clinically,318 cases(97.24%)of the lesion were diagnosed as cosmetic contact dermatitis.7 acne and 2 skin discoloration.Conclusion Cosmetic contact dermatitis is the most common cosmetic dermatosis,and the young and middle-aged females with middle or high education are the most susceptible people to cosmetic dermatosis.

Objective To study the pre-and post-surgical orthodontic treatment methods of patients with skeletal malocclusion treated through combined orthodontic-orthognathic surgery,and to set some guidance for the future clinical Work.Methods Twenty-five skeletal malocclusion patients in our clinic aged from 17 to 36 were treated by presurgical orthodontic treatment,orthognathic surgery and postsurgical ortho dontic treatment.Presurgical orthodontic treatment included alignment of dental arches,leveling of arches,elimination of rotations,coordination of the arches,and decompensation of anterior and posterior teeth.The postsurgical orthodontic treatment included closing residual spacing,final tooth alignment,maximum interdigitation,finalizing torque,artistic positioning,ideal overjet/overbite relationship and establishment of correct root parallelism.Results The duration of presurgical orthodontic treatment was 14.41 months on average(2～23 months),and the postsurgical orthodontic treatment time was 6.94 months on average(1.5～13.5 months).The duration for the whole active treatment was 21.35 months on average(7～35 months).The maxilla was moved back on an average 5.00 mm in maxillary protrusion cases.The mandible was moved anteriorly on an average 7.25 mm in mandibular retrusion cases.The mandible was moved back on an average 6.55 mm in mandibular protrusion cases.The chin was moved anteriorly on an average 5.33 nan in retrusion of chin cases.Conclusions Pre-and post-surgical orthodontic treatments are important procedures to the surgical treatment for skeletal malocclusion and basic needs to obtain successful treatment results.

Objective To explore the effect of botulinum toxin type A(BTXA)in the treatment of early hypertrophic scars(HTS).Methods BTXA was injected into and around the eady HTS,and then the modal and histological changes of the scars as well as the clinical reaction were observed in the patient.BTXA was also injected into muscle around the incision and effect on the cicatrization observed.Results Injection of BTXA could obviously alleviate ache and pruritus of eady HTS and could impel the atrophy and inteneration of eady HTS.Changes were found in paraffin-embedded tissue section by the hemetoxylin and eosin(HE)staining.Injection of BTXA into muscle around the cut could can reduce occurrence of HTS.Conclusion BTXA can help prevent the early HTS to a certain extent.The mechanism underlying this effect may be related to the reducing the tension around scars and proliferative activity,interfering with the signal transduction of small nerves,affecting the proliferation and apoptosis of fibroblasts and subsequently decreasing the collagen synthesis.

Objective To evaluate the clinical therapeutic effects of Vbeam 595 nm pulsed dye laser in114 cases of port wine stains.Methods 114 patients with port wine stains were treated with Vbeam 595 nm pulsed dye laser with 3～10 ms pulse width and 7mm spot size.The energy fluence used varied from 10 to 15 J/cm2.Dynamic cooling device(DCD)was used to protect epiderm,with DCD spray 30～40 ms and DCD delay 10～30 ms.The interval of therapy was 4～8 weeks.The results were graded on basis of cleaning and fading as follows:grade Ⅰ(＞75%),gradeⅡ(50%to 74%),grade Ⅲ(25%to 49%),and grade Ⅳ(＜25%).Results 114 patients completed the therapy.The number of treatments ranged from 1 to 10(mean 5.9).The results evaluated as grades Ⅰ,Ⅱ,Ⅲ and Ⅳ were 74 patients(64.9%),29 patients(25.4%),9 patients(7.9%)and 2 patients(1.8%),respectively.The therapeutic effect was analysed according to number of treatments.the ages of patients,site and color of the lesions.It was found that the therapeutic effect was prominent in patients of younger age,with pink lesions located on the neck and face.No recurrence and scar happened after 6 months to 2 years follow-up.Conclnsions Vbeam 595nm pulsed dye laser is a safe and effective method for the treatent of port wine stains,with less complications.

Objective To evaluate the clinical application of fat granule auto-graft in facial soft tissue depression reconstruction.Methods Autologous subcutaneous fat granules were obtained by syringe aspiration from donating site.then washed with normal saline.Small amounts of fat granules were injected into the facial sites with soft tissue depression by means of multiple passes immediately.Results We performed such fat iniection in a total of 18 cases,all of the procedures were safe and successful.In most cases,single injection were enough,only one underwent two sessions of fat iniection.All members were followed-up for 1.5 months to 24months,the average were 14 months.All facial tissue depression were reconstructed for difierent degrees.The rate of fullness and symmetry.fullness and pretty symmetry and fullness with little asymmetry were 77.8%,16.7%and 5.5%.respectively.No infection,fat necrosis or liquefaction occured.Conclusion Being satisfled in correction of deformity of facial depression.the implantation of autologous fat globules iS safe and effective with less side-effects.

Objective To explore the procedures of breast repair and reconstruction after mastectomy with three methods for optimal appearances of the breast.Methods Three methods were adopted in this study:(1)Two-stage breast reconstruction operation with ampliate latissimus dorsi myocutaneous flap after mastectomy;(2)One stage breast reconstruction operation with transverse rectus adbominis myocutaneous(TRAM)flap after mastectomy;and(3)Two-stage breast reconstruction and nipple repair operation with tissue expander/implant after mastectomy preserving pectoralis major museulus or implants along under pectoralis major musculus.Results All of the flaps survived well and were well-shaped in total 10 patients(10 breasts)with a flap breast reconstruetion,in which the superior ratios were 83.33%.The appearance and volume were not satisfactory in 1 patiant treated with the method of tissue expander/implant,because the volume of tissue inflation was smaller than another one and 100 ml implant was applied.The partial flap necrosis occurred in 1 case with the method of TRAM flap.Conclusions With the development of plastic surgery technique,the appearances and shapes of reconstructed breast achieve the satisfactory effects.After the ampliate latissimus dorsi myocutaneous flap is applied,the appearance and volume of reconstructed breast are similar to the healthy one.The two-stage nipple repair operation is applied with breast reconstruction operation by the tissue expander/implant after mastectomy preserving pectoralis major musculus.According to the different methods of mastectomy to choose suitable procedures of breast reconstruction,the satisfactory appearances and psychotherapy will be achieved.