A prospective study on the expansion rule of the directional skin and soft tissue expander in abdominal scar reconstruction / 中华烧伤杂志

Objective: To observe the expansion rule of directional skin and soft tissue expander (hereinafter referred to as expander) in abdominal scar reconstruction. Methods: A prospective self-controlled study was conducted. Twenty patients with abdominal scar who met the inclusion criteria and admitted to Zhengzhou First People's Hospital from January 2018 to December 2020 were selected by random number table method, including 5 males and 15 females, aged 12-51 (31±12) years, with 12 patients of type Ⅰ scar and 8 patients of type Ⅱ scar. In the first stage, two or three expanders with rated capacity of 300-600 mL were placed on both sides of the scar, of which at least one expander had rated capacity of 500 mL (as the follow-up observation object). After the sutures were removed, water injection treatment was started, with the expansion time of 4 to 6 months. After the water injection volume reached 2.0 times of the rated capacity of expander, abdominal scar excision+expander removal+local expanded flap transfer repair was performed in the second stage. The skin surface area at the expansion site was measured respectively when the water injection volume reached 1.0, 1.2, 1.5, 1.8, and 2.0 times of the rated capacity of expander, and the skin expansion rate of the expansion site at corresponding multiples of expansion (1.0, 1.2, 1.5, 1.8, and 2.0 times) and adjacent multiple intervals (1.0-1.2, 1.2-1.5, 1.5-1.8, and 1.8-2.0 times) were calculated. The skin surface area of the repaired site at 0 (immediately), 1, 2, 3, 4, 5, and 6 months after operation, and the skin shrinkage rate of the repaired site at different time points (1, 2, 3, 4, 5, and 6 months after operation) and different time periods (0-1, 1-2, 2-3, 3-4, 4-5, and 5-6 months after operation) were calculated. Data were statistically analyzed with analysis of variance for repeated measurement and least significant difference-t test. Results: Compared with the expansion of 1.0 time ((287.6±2.2) cm2 and (47.0±0.7)%), the skin surface area and expansion rate of the expansion site of patients ((315.8±2.1), (356.1±2.8), (384.9±1.6), and (386.2±1.5) cm2, (51.7±0.6)%, (57.2±0.6)%, (60.4±0.6)%, and (60.5±0.6)%) were significantly increased when the expansion reached 1.2, 1.5, 1.8, and 2.0 times (with t values of 46.04, 90.38, 150.14, 159.55, 45.11, 87.83, 135.82, and 118.48, respectively, P<0.05). Compared with the expansion of 1.2 times, the skin surface area and expansion rate of the expansion site of patients were significantly increased when the expansion reached 1.5, 1.8, and 2.0 times (with t values of 49.82, 109.64, 122.14, 144.19, 49.51, and 105.85, respectively, P<0.05). Compared with the expansion of 1.5 times, the skin surface area and expansion rate of the expansion site of patients were significantly increased when the expansion reached 1.8 times (with t values of 38.93 and 39.22, respectively, P<0.05) and 2.0 times (with t values of 38.37 and 38.78, respectively, P<0.05). Compared with the expansion of 1.8 times, the skin surface area and expansion rate of the expansion site of patients both had no statistically significant differences when the expansion reached 2.0 times (with t values of 4.71 and 4.72, respectively, P>0.05). Compared with the expansion of 1.0-1.2 times, the skin expansion rate of the expansion site of patient was significantly increased when the expansion reached 1.2-1.5 times (t=6.95, P<0.05), while the skin expansion rate of the expansion site of patient was significantly decreased when the expansion reached 1.5-1.8 and 1.8-2.0 times (with t values of 5.89 and 40.75, respectively, P<0.05). Compared with the expansion of 1.2-1.5 times, the skin expansion rate of the expansion site of patient was significantly decreased when the expansion reached 1.5-1.8 and 1.8-2.0 times (with t values of 10.50 and 41.92, respectively, P<0.05). Compared with the expansion of 1.5-1.8 times, the skin expansion rate of the expansion site of patient was significantly decreased when the expansion reached 1.8-2.0 times (t=32.60, P<0.05). Compared with 0 month after operation, the skin surface area of the repaired site of patient at 1, 2, 3, 4, 5, and 6 months after operation was significantly decreased (with t values of 61.66, 82.70, 96.44, 102.81, 104.51, and 102.21, respectively, P<0.05). Compared with 1 month after operation, the skin surface area of the repaired site of patient was significantly decreased at 2, 3, 4, 5, and 6 months after operation (with t values of 37.37, 64.64, 69.40, 72.46, and 72.62, respectively, P<0.05), while the skin shrinkage rate was significantly increased (with t values of 32.29, 50.00, 52.67, 54.76, and 54.62, respectively, P<0.05). Compared with 2 months after operation, the skin surface area of the repaired site of patient was significantly decreased at 3, 4, 5, and 6 months after operation (with t values of 52.41, 60.41, 70.30, and 65.32, respectively, P<0.05), while the skin shrinkage rate was significantly increased (with t values of 52.97, 59.29, 69.68, and 64.50, respectively, P<0.05). Compared with 3 months after operation, the skin surface area of the repaired site of patient was significantly decreased at 4, 5, and 6 months after operation (with t values of 5.53, 38.00, and 38.52, respectively, P<0.05), while the skin shrinkage rate was significantly increased (with t values of 25.36, 38.59, and 37.47, respectively, P<0.05). Compared with 4 months after operation, the skin surface area (with t values of 41.10 and 50.50, respectively, P>0.05) and skin shrinkage rate (with t values of 48.09 and 50.00, respectively, P>0.05) of the repaired site of patients at 5 and 6 months after operation showed no statistically significant differences. Compared with 5 months after operation, the skin surface area and skin shrinkage rate of the repaired site of patient at 6 months after operation showed no statistically significant differences (with t values of 9.40 and 9.59, respectively, P>0.05). Compared with 0-1 month after operation, the skin shrinkage rate of the repaired site of patient at 1-2, 2-3, 3-4, 4-5, and 5-6 months after operation was significantly decreased (with t values of 13.56, 40.00, 49.21, 53.97, and 57.68, respectively, P<0.05). Compared with 1-2 months after operation, the skin shrinkage rate of the repaired site of patients at 2-3, 3-4, 4-5, and 5-6 months after operation was significantly decreased (with t values of 12.37, 27.72, 30.16, and 31.67, respectively, P<0.05). Compared with 2-3 months after operation, the skin shrinkage rate of the repaired site of patients at 3-4, 4-5, and 5-6 months after operation was significantly decreased (with t values of 33.73, 41.31, and 54.10, respectively, P<0.05). Compared with 3-4 months after operation, the skin shrinkage rate of the repaired site of patient at 4-5 and 5-6 months after operation showed no statistically significant differences (with t values of 10.90 and 23.60, respectively, P>0.05). Compared with 4-5 months after operation, the skin shrinkage rate of the repaired site of patient at 5-6 months after operation showed no statistically significant difference (t=20.90, P>0.05). Conclusions: The expander can effectively expand the abdominal skin, thus repairing the abdominal scar deformity. Maintained expansion for one month after the water injection expansion reaches 1.8 times of the rated capacity of the expander can be set as a phase Ⅱ operation node.

Effects of expanded frontal-parietal pedicled flap in reconstructing cervical scar contracture deformity in children after burns / 中华烧伤杂志

Objective: To explore the effects of expanded frontal-parietal pedicled flap in reconstructing cervical scar contracture deformity in children after burns. Methods: A retrospective observational study was conducted. From January 2015 to December 2020, 18 male children with cervical scar contracture deformity after burns who met the inclusion criteria were admitted to Zhengzhou First People's Hospital, aged 4 to 12 years, including 10 cases with degree Ⅱ cervical scar contracture deformity and 8 cases with degree Ⅲ scar contracture deformity, and were all reconstructed with expanded frontal-parietal pedicled flap. The surgery was performed in 3 stages. In the first stage, a cylindrical skin and soft tissue expander (hereinafter referred to as expander) with rated capacity of 300 to 500 mL was placed in the frontal-parietal region. The expansion time was 4 to 6 months with the total normal saline injection volume being 2.1 to 3.0 times of the rated capacity of expander. In the second stage, expander removal, scar excision, contracture release, and flap transfer were performed, with the flap areas of 18 cm×9 cm to 23 cm×13 cm and the secondary wound areas of 16 cm×8 cm to 21 cm×11 cm after scar excision and contracture release. After 3 to 4 weeks, in the third stage, the flap pedicle was cut off and restored. The rated volume of placed expander, total normal saline injection volume, type of vascular pedicle of flap, survival of flap and reconstruction of scar after the second stage surgery were recorded. The neck range of motion and cervico-mental angle were measured before surgery and one-year after surgery. The appearance of neck, occurrence of common complications in the donor and recipient sites of children, and satisfaction of children's families for treatment effects were followed up. Data were statistically analyzed with paired sample t test. Results: All the patients successfully completed the three stages of operation. The rated volume of implanted expander was 300 mL in 6 children, 400 mL in 9 children, and 500 mL in 3 children, with the volume of normal saline injection being 630 to 1 500 mL. The type of vascular pedicle of flap was double pedicle in 13 cases and was single pedicle in 5 cases. All the flaps in 17 children survived well, and the secondary wounds after neck scar excision and contracture release were all reconstructed in one procedure. In one case, the distal blood supply of the single pedicled flap was poor after the second stage surgery, with necrosis of about 2.5 cm in length. The distal necrotic tissue was removed on 10 days after the operation, and the wound was completely closed after the flap was repositioned. In the follow-up of 6 months to 3 years post operation, the cervical scar contracture deformity in 18 children was corrected without recurrence. The flap was not bloated, the texture was soft, and the appearances of chin and neck were good. The range of motion of cervical pre-buckling, extension, left flexion, and right flexion, and cervico-mental angle in one year after operation were improved compared with those before operation (with t values of 43.10, 22.64, 27.96, 20.59, and 88.42, respectively, P<0.01). The incision in the frontal donor site was located in the hairline, the scar was slight and concealed. No complication such as cranial depression was observed in expander placement site, and the children's families were satisfied with the result of reconstruction. Conclusions: Application of expanded frontal-parietal pedicled flap in reconstructing the cervical scar contracture deformity in children after burns can obviously improve the appearance and function of neck, with unlikely recurrence of postoperative scar contractures, thus it is an ideal method of reconstruction.

Predictive value of D-dimer for deep venous thrombosis of lower extremity in adult burn patients / 中华烧伤杂志

Objective: To investigate the predictive value of D-dimer for deep venous thrombosis (DVT) of lower extremity in adult burn patients. Methods: A retrospective case series study was conducted. The clinical data of 3 861 adult burn patients who met the inclusion criteria and were admitted to the Department of Burns of Zhengzhou First People's Hospital from January 1, 2015 to December 31, 2019 were collected. The patients were divided into DVT group (n=77) and non-DVT group (n=3 784) according to whether DVT of lower extremity occurred during hospitalization or not. Data of patients in the two groups were collected and compared, including the gender, age, total burn area, D-dimer level, with lower limb burn and inhalation injury or not on admission, with sepsis/septic shock, femoral vein indwelling central venous catheter (CVC), history of surgery, and infusion of concentrated red blood cells or not during hospitalization. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. The indicators with statistically significant differences between the two groups were analyzed with multivariate logistic regression analysis to screen the independent risk factors for DVT of lower extremity in 3 861 adult burn patients. The receiver operating characteristic (ROC) curve of the independent risk factors predicting DVT of lower extremity in 3 861 adult burn patients were drawn, and the area under the curve (AUC), the optimal threshold value, and the sensitivity and specificity under the optimal threshold value were calculated. The quality of the AUC was compared by Delong test, and the sensitivity and specificity under the optimal threshold value were compared using chi-square test. Results: There were no statistically significant differences in gender, occurrence of sepsis/septic shock or history of surgery during hospitalization between patients in the two groups (P>0.05), while there were statistically significant differences in age, total burn area, D-dimer level, lower limb burn and inhalation injury on admission, and femoral vein indwelling CVC and infusion of concentrated red blood cells during hospitalization between patients in the two groups (t=-8.17, with Z values of -5.04 and -10.83, respectively, χ2 values of 21.83, 5.37, 7.75, and 4.52, respectively, P<0.05 or P<0.01). Multivariate logistic regression analysis showed that age, total burn area, and D-dimer level were the independent risk factors for DVT of lower extremity in 3 861 adult burn patients (with odds ratios of 1.05, 1.02, and 1.14, respectively, 95% confidence intervals of 1.04-1.06, 1.00-1.03, and 1.10-1.20, respectively, P<0.05 or P<0.01). The AUCs of ROC of age, total burn area, and D-dimer level for predicting DVT of lower extremity in 3 861 adult burn patients were 0.74, 0.67, and 0.86, respectively (with 95% confidence intervals of 0.68-0.80, 0.60-0.74, and 0.83-0.89, respectively, P values<0.01), the optimal threshold values were 50.5 years old, 10.5% total body surface area, and 1.845 mg/L, respectively, the sensitivity under the optimal threshold values were 71.4%, 70.1%, and 87.0%, respectively, and the specificity under the optimal threshold values were 66.8%, 67.2%, and 72.9%, respectively. The AUC quality and sensitivity and specificity under the optimal threshold value of D-dimer level were significantly better than those of age (z=3.29, with χ2 values of 284.91 and 34.25, respectively, P<0.01) and total burn area (z=4.98, with χ2 values of 326.79 and 29.88, respectively, P<0.01), while the AUC quality and sensitivity and specificity under the optimal threshold values were similar between age and total burn area (P>0.05). Conclusions: D-dimer level is an independent risk factor for DVT of lower extremity in adult burn patients, its AUC quality and sensitivity and specificity under the optimal threshold value are better than those of age and total burn area, and it has good predictive value for DVT of lower extremity in adult burn patients.

Clinical effects of free hallux-nail flap combined with the second toe composite tissue flap in the reconstruction of damaged thumb after electrical burns / 中华烧伤杂志

Objective: To explore the clinical effects of free hallux-nail flap combined with the second toe composite tissue flap in the reconstruction of damaged thumb after electrical burns. Methods: A retrospective observational study was conducted. From May 2018 to April 2021, 12 male patients with thumb destructive defects caused by electrical burns who met the inclusion criteria were admitted to Zhengzhou First People's Hospital, aged 27 to 58 years, including 10 cases with degree Ⅲ thumb defect and 2 cases with degree Ⅳ thumb defect after thorough debridement. The thumb was reconstructed with free hallux-nail flap combined with composite tissue flap of the second phalangeal bone, joint, and tendon with skin island. The donor site of hallux-nail flap was covered with artificial dermis in the first stage and performed with continuous vacuum sealing drainage, and covered with medium-thickness skin graft from the groin site in the second stage. The donor site in the second toe was filled and fixed with iliac bone strips. The survival of reconstructed thumb was observed 1 week after the reconstruction surgery, the survival of skin graft in the donor site of hallux-nail flap was observed 2 weeks after skin grafting, and the callus formation of the reconstructed thumb phalanx and the second toe of the donor foot was observed by X-ray 6 weeks after the reconstruction surgery. During the follow-up, the shape of reconstructed thumb was observed and the sensory function was evaluated; the function of reconstructed thumb was evaluated with trial standard for the evaluation of the functions of the upper limbs of the Hand Surgery Society of the Chinese Medical Association; whether the interphalangeal joints of the hallux and the second toe were stiff, the scar hyperplasia of the foot donor site, and whether the walking and standing functions of the donor feet were limited were observed. Results: One week after the reconstruction surgery, all the reconstructed thumbs of the patients survived. Two weeks after skin grafting, the skin grafts in the donor site of hallux-nail flap of 11 patients survived, while the skin graft in the donor site of hallux-nail flap of 1 patient was partially necrotic, which was healed completely after 10 days' dressing change. Six weeks after the reconstruction surgery, callus formation was observed in the reconstructed thumb and the second toe of the donor foot of 10 patients, the Kirschner wires were removed; while callus formation of the reconstructed thumb was poor in 2 patients, and the Kirschner wires were removed after 2 weeks of delay. During the follow-up of 6 to 24 months, the shape of reconstructed thumb was similar to that of the healthy thumb, the discrimination distance between the two points of the reconstructed thumb was 7 to 11 mm, and the functional evaluation results were excellent in 4 cases, good in 6 cases, and fair in 2 cases. The interphalangeal joints of the hallux and the second toe of the donor foot were stiff, mild scar hyperplasia was left in the donor site of foot, and the standing and walking functions of the donor foot were not significantly limited. Conclusions: The application of free hallux-nail flap combined with the second toe composite tissue flap in the reconstruction of damaged thumb after electrical burns adopts the concept of reconstruction instead of repair to close the wound. It can restore the shape and function of the damaged thumb without causing great damage to the donor foot.

Effect of disinfectant with benzethon chloramine and isopropanol as main active ingredients on the accuracy of dental impression / 北京大学学报(医学版)

OBJECTIVE@#To assess the effect of disinfectant (Cavicide) with benzethon chloramine and isopropanol as main active ingredients disinfectant on dental impression accuracy.@*METHODS@#The effect of Cavicide on three impression materials (alginate, polyether and vinylpolysiloxane) were assessed using a standard model. The standard model was digitized by an extraoral scanner (IScan D103i, Imetric). For each kind of impression materials, thirty impressions were taken following the manufactures' instruction in the same conditions. Subsequently, the impressions were randomly divided into three groups, with ten impressions in each group. After the impression taking was completed, the three groups underwent pure water rinse for 1 min (blank control, BC), 2% glutaraldehyde solution immersion disinfection for 30 min (glutaraldehyde, GD), and Cavicide solution spray disinfection for 5 min (Cavicide, CC), respectively. All the impressions were digitized by the extraoral scanner (IScan D103i, Imetric) after disinfection and exported to a dedicated three-dimensional analysis software (Geomagic Qualify 2014, Geomagic, USA). In the software, the digital models of the impressions were trimmed to teeth and then superimposed with the digitized standard model via best-fit alignment. Root mean square (RMS) was used to evaluate the deviations between the impression and the standard model. The deviation in the anterior and posterior regions was evaluated respectively. One-way ANOVA test and the LSD post-hoc test were used to compare the deviations between the three groups (P < 0.05). The color map of each superimposition was saved for visual analysis.@*RESULTS@#For the polyether and vinylpolysiloxane materials, the difference between the three groups was not statistically significant (P=0.933, P=0.827). For the alginate material, the difference in posterior region between group GD and group BC, as well as group GD and group CC were statistically significant (GD vs. BC, P=0.001; GD vs. CC, P=0.002), while the difference between group BC and group CC was not statistically significant (P=0.854). The visual analysis showed an obvious deviation in the buccal-lingual direction in group GD.@*CONCLUSION@#Disinfectant (Cavicide) with benzethon chloramine and isopropanol as main active ingredients using spray disinfection has no effect on the accuracy of the alginate, polyether and vinylpolysiloxane impressions.

Digital workflow coupling conic retention for the immediate restoration of adjacent posterior implants / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the digital workflow coupling conic retention for the immediate restoration of adjacent posterior implants.@*METHODS@#The patients with adjacent teeth missing in the posterior jaw seeking for implant restoration in the Department of Implantology, Peking University School and Hospital of Stomatology from March, 2017 to February, 2018 were recruited. After implant placement and commercial conic retention coping delivery, the patient had an intraoral scan for digital impression, and the computer-assisted design/computer-assisted manufacturing (CAD/CAM) technology was used for the fabrication of the immediate splinted prosthesis, which was made of polymethyl methacrylate (PMMA) and loaded immediately after delivery. Six months later, all the temporary prostheses were replaced by the permanent ones made of monolithic zirconia with CAD/CAM technology as well. The parallel periapical films were taken for the temporary and permanent prostheses post-delivery. The clinical effect of this workflow was evaluated by indices including the survival rates of implants and prostheses, the change of marginal bone level, and the implant-related and prosthesis-related complications; before the final restoration, the Visual Analogue Score (VAS) was used to evaluate the satisfaction of the patients.@*RESULTS@#Ten patients (4 males and 6 females, 55.5 years old for average) were recruited. Totally 34 implants were placed; 14 prostheses were fabricated, temporary and permanent, respectively. After an observation period from 4 to 14 months, the survival rate for implants and prostheses were both 100%; the marginal bone level of the implants were (1.06±0.97) mm and (0.96±0.82) mm, immediate post-operation and 6 months later, respectively. The difference was not statistically significant (P>0.05). Neither implant- nor prostheses- related complications were observed. And the VAS of the patients' satisfaction was 87.2.@*CONCLUSION@#For the adjacent posterior implants, the immediate prostheses manufactured by digital workflow, coupling conic retention, were clinically feasible and patient-satisfactory.

Validation of the digital integration technology for evaluating the nasolabial morphology variation after the cross-arch fixed restoration of maxillary implant-supported prostheses / 北京大学学报(医学版)

OBJECTIVE@#To explore the applicability of integration between three-dimensional (3D) facial and dental data to evaluate the nasolabial morphology variation before and after the cross-arch fixed restoration of the maxillary implant-supported prostheses.@*METHODS@#Twelve patients (4 women and 8 men), mean age (54.82±5.50) years (from 45 to 62 years) referred to the Department of Oral Implan-tology, Peking University School and Hospital of Stomatology, were selected and diagnosed with edentulous maxilla. For all the patients, 4 to 6 implants were inserted into the maxilla. Six months later, the final cross-arch fixed prostheses were delivered. The 3D facial images were collected before and after the final restoration. The 3D data of prostheses were also captured. All the 3D data were registered and measured in the same coordinate system. Then the displacement of all the landmarks [cheilion left (CHL), cheilion right (CHR), crista philtri left (CPHL), crista philtri right (CPHR), labrale supe-rius (LS), subnasale (SN), stomion (STO), upper incisor (UI), upper flange border of the prostheses (F-point, F)], and the variation of the distances between these landmarks (SN-LS, CPHR-CPHL, CHR-CHL, LS-STO) were analyzed and compared.@*RESULTS@#The consistency test among three measurements of the length of F-SN indicated that the integration method of the dental prostheses and soft tissue had the good repetitiveness, ICC=0.983 (95%CI: 0.957-0.995). After wearing the final cross-arch maxillary implant-supported prostheses, all the landmarks on the soft tissue moved forward. The nasal base area changed minimally, and the shift of SN in the sagittal direction was only (0.61±0.44) mm. But the sagittal shift of LS was (3.12±1.38) mm. In the vertical direction, SN, LS, CPHL, and CPHR moved upward. But STO, CHL, and CHR moved downward a little. Except for the slight decrease of the length of philtrum (SN-LS), the length of CHL-CHR, CPHL-CPHR, and the height of upper lip were increased together (P < 0.01). In the direction of Z axis, the strong correlations were found not only between the movements of SN and F (r=0.904 3) but also between the movements of LS and UI (r=0.958 4).@*CONCLUSION@#The integration method of 3D facial and dental data showed good repetitiveness. And the strong correlations between the landmarks of prostheses and nasolabial soft tissue in the sagittal direction were found by this new method.

Quantitative three-dimensional methodology based on intraoral scan to assess the soft tissue contour alterations following single immediate implant and immediate provisionalization in maxillary central incisor: a 1-year prospective study / 中华口腔医学杂志

Objective@#To establish a quantitative three-dimensional method based on intraoral scan and apply it to evaluation of the facial soft tissue contour alterations following single immediate implant and immediate provisionalization (IIPP) in central incisor via intraoral scanning.@*Methods@#This study was a prospective clinical study. The trial was conducted at Department of Implantology, Peking University School and Hospital of Stomatology, from January 2016 to September 2017. Twenty-nine eligible consecutive patients (15 women, 14 men) with a mean age of (34.3±12.0) were included and received immediate replacement of the failure maxillary single central incisor. A screw-retained immediate restoration was delivered for each patient. At 6-month follow-up, impression was taken and a screw-retained permanent restoration was performed for each patient. The anterior maxillary region was scanned by an intraoral scanning system at pre-surgery and 1-year follow-up. The Standard Tessellation Language (STL) files were output to a dedicated software and superimposed. Mid-facial recession and gingival zenith symmetry at 1-year follow-up were measured in the digital models. Three-dimensional configurations of the contour change volume were calculated and reconstructed for visual analysis. Furthermore, the following parameters were used to analyze the reconstructed volume: mean contour change in thickness (△d), mesio-distal width (DW), coronal-apical height (DH), contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site.@*Results@#Twenty-seven out of twenty-nine enrolled patients were finally available for analysis. At 1-year follow-up, the mid-facial mucosa level at implant site was (0.23±0.39) mm apical to the gingival zenith of the contralateral tooth. In general, a contour collapse was found in every patient. △d, DW and DH of the collapsed volume were (0.62±0.22), (11.03±1.74) and (6.82±1.52) mm, respectively. Contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site were (0.54±0.48), (0.87±0.62), (1.03±0.46), (0.96±0.52), (0.90±0.52), (0.89±0.57) mm.@*Conclusions@#The described quantitative measurement based on intraoral scan can be an effective method for assessment of soft tissue contour changes. At 1 year following single IIPP treatment in maxillary incisor, free gingival margin is stable, with only mild recession. The mean level of the facial soft tissue contour collapse is 0.62 mm.

Application of and progress in computer aided design and computer aided manufacture materials by chairside digital workflow in implant prosthodontics / 中华口腔医学杂志

With the emergence and development of new dental materials, chairside computer aided design/computer aided manufacture (CAD/CAM) materials, as an important part of digital technology, is gaining increasing progress to meet the needs of implant restorations and digital processing technology for the mechanical properties, chemical stability, biocompatibility and processing properties. A large number of in-vitro experiments and clinical studies have been reported on various materials, such as polycrystalline ceramic, glass ceramic and indirect composite. The purpose of this article is to review the performance, the clinical indications and applications of the CAD/CAM materials for chairside digital workflow in implant prosthodontics.

Effects of CAD/CAM titanium alloy surface treatment and resin luting on shear bond strength and durability of composite resin / 北京大学学报(医学版)

OBJECTIVE@#To assess the effects of two surface treatments (sandblasting, SB; microarc-oxidation, MAO) and resin luting on shear bond strength and durability of titanium alloy and composite-resin.@*METHODS@#Eighty cylindrical titanium alloy specimens with a diameter of 10 mm and a height of 8 mm were fabricated by CAD/CAM technique. It was divided into two groups according to the surface treatment methods: sandblasting with Al2O3 particles on the surface of SB specimens; porous ceramic film structure could be formed on the surface of MAO specimens after surface treatment. Each group was classified into SB-resin luting-N group (not used), SB-resin luting-Y group (used), MAO-resin luting-N group (not used), MAO-resin luting-Y group (used) depending on whether or not resin luting was applied. Each specimen was bonded and cured with the Cemerage resin, and the shear bond strength after 0 and 5 000 thermocycling was tested. The results were statistically analyzed. The surface morphology of titanium alloy specimens before and after the shear bond strength test was observed by scanning electron microscopy (SEM).@*RESULTS@#The shear bond strength between titanium alloy and composite-resin was the highest in the SB combined with resin luting group after 0 thermocycling (16.2±1.8) MPa; was the lowest in MAO group after 5 000 thermocycling (8.9±1.5) MPa. The shear bond strength of SB and MAO surface treatment methods combined without resin luting group after 5 000 thermocycling were (10.7±2.2) MPa and (8.9±1.5) MPa, which were statistically lower than those in the thermocycling 0 (P=0.000 and P=0.001). The shear bond strength of SB and MAO surface treatment methods combined with resin luting group after 5 000 thermocycling were (15.5±2.1) MPa and (11.7±1.3) MPa, respectively, which were lower than those in the thermocycling 0 group, but there was no statistical significance (P=0.087 and P=0.234).@*CONCLUSION@#Both the surface treatment methods of SB and MAO combined with resin luting can improve the shear bond strength and durability of titanium alloy and composite-resin. The SB combined with resin luting is more significant. At present, the effect of SB is better than that of MAO due to the limitation of technical parameters of micro-arc oxidation.

Anatomic variations and lesions of the maxillary sinus observed by CBCT before sinus augmentation in 666 sinuses of 589 patients / 实用口腔医学杂志

Objective: To observe the anatomic variations and lesions of maxillary sinus by CBCT before sinus augmentation in Chinese patients with edentulous posterior maxilla. Methods: 589 participants with 666 sinuses were enrolled in this study. The anatomic variations and lesions of maxillary sinus were examined by CBCT prior to sinus augmentation surgery. Results: In all 666 sinuses, the prevalence of septa was 30. 48％, membrane thickness ≤2 mm was 60. 36％, the average thickness of the lateral wall was (1. 38 ± 0. 05) mm, the prevalence of posterior superior alveolar artery in the sinus was 66. 52％, the average diameter of the artery was (0. 98 ± 0. 03) mm, the discontinuity of the sinus floor was 4. 35％, the mean width of maxillary sinus was (14. 20 ± 0. 19) mm, and the prevalence of cyst was 11. 41％. Conclusion: CBCT can reveal the sinus diversity and provide the information for the safe and effective sinus augmentation.

Complications of implant-supported full-arch immediate prosthesis: a retrospective analysis of 114 cases / 中华口腔医学杂志

Objective@#To evaluate the feasibility of long-term function of implant-supported full-arch immediate prosthesis via assessing the complications and risk factors.@*Methods@#This historical cohort study included patients treated with implant-supported full-arch restoration under immediate loading protocol between April, 2008 to June, 2016 and wearing the immediate prosthesis for more than 6 months. Medical charts were reviewed for patients' general information, implant information, prosthetic information and details of prosthetic complications. COX proportional hazards ratio model was adopted to analyze the potential risk factors for prosthesis fracture.@*Results@#A total of 114 patients with a mean age of (56.7±10.2) years old and 144 prostheses were included. The median wearing time of immediate prosthesis was 17.6 months. Sixty-two (54%) patients experienced prosthetic complication, 30 of them suffered more than once. Artificial teeth fractures were more common in anterior region while resin base fractured more often in the posterior region. The possibility of immediate prosthesis fracture in the first year was high but declined over the following years. COX regression analysis showed that fibre-reinforcement (HR=0.486, P=0.017) and rigid opposing dentition (HR=2.272, P=0.016) were significantly related to the prosthesis fracture.@*Conclusions@#Long-term function of implant-supported full-arch immediate prosthesis renders a high prosthetic complication prevalence, featuring the prosthesis fracture as the most common complication and the first year of highest fracture probability. Fibre-reinforced acrylic immediate prosthesis may function well in cases with a removable denture restored opposing jaw.

Lateral cephalometric analysis of patients with maxillary alveolar protrusion and advanced periodontitis treated with immediate implants and cross-arch fixed prostheses / 中华口腔医学杂志

Objective@#To investigate the changes of the lateral cephelometric landmarks of soft tissue and hard tissue of patients with maxillary alveolar protrusion and advanced periodontitis treated with immediate implants and cross-arch fixed prostheses.@*Methods@#From January 2013 to October 2016, consecutive patients with advanced periodontitis and maxillary alveolar protrusion in need of immediate implants and cross-arch fixed prostheses were included in this study. All the patients were treated with provisional cross-arch fixed prostheses supported with 4 to 6 immediate implants after extraction of all the residual teeth and reduction of excessive alveolar bone. After 6 months, a final cross-arch fixed prosthesis was delivered. The lateral cephalometric landmarks of soft tissue and hard tissue at the time of pre-operation and final prosthesis delivery were analyzed. The change of patients' facial aesthetics was assessed using visual analogue scale (VAS).@*Results@#Ten patients were included in the study. All the patients underwent full arch rehabilitation of both jaws supported by a total of 89 dental implants. In the maxillae, the average number of inserted implants were 4.5. The mean height of alveolar bone reduction was (6.3±1.8) mm. Both the distance of U1-NA (the upper incisor to nasion-A point line) and U1-PP (the upper incisor to palatal plane) were significantly reduced by (5.5±2.7) mm and (1.6±1.2) mm, respectively. The angle of U1-SN (between upper incisor to sella-nasion line) was reduced by 9.6°±8.1°palatally. The nasolabial angles were significantly increased by 10.5°±6.4°. Both the patients and dentists considered that the facial aesthetics was improved greatly after the treatment.@*Conclusions@#With the reduction of excessive alveolar bone and the realignment of artificial teeth, the treatment of immediate implants and cross-arch fixed prostheses could improve the facial aesthetics of the patients with advanced periodontitis and maxillary alveolar protrusion.

Systematic review and meta-analysis on the effect of implant supported overdentures on the oral health related quality of life of edentulous patients / 中华口腔医学杂志

Objective@#To evaluate the effect of implant related treatment on the oral health related quality of life (OHRQoL) of edentulous patients.@*Methods@#The CNKI, Wanfang database and Medline, EMBASE, Cochrane Library databases that include randomized clinical trials comparing implant supported overdentures with conventional complete denture for edentulous patients were retrived. Nine studies involving 769 cases were included and meta-analysis was conducted.@*Results@#The standardized mean difference (SMD) of oral health impact profile (OHIP) score was 1.63 (95%CI: 1.25-2.02) and improved after implant related treatment, which was significantly better than the conventional complete denture (0.87, 95% CI: 0.54-1.20).@*Conclusions@#Implant supported overdentures improved patient's OHRQoL and showed better performance compared to the overdentures complete dentures.

A pilot clinical study of immediate provisionalization with a chairside computer aided design and computer aided manufacture monolithic crown for single tooth immediate implant placement / 中华口腔医学杂志

Objective@#To evaluate the primary clinical outcomes of immediate provisionalization with a monolithic crown utilizing a novel chairside computer aided design and computer aided manufacture (CAD/CAM) workflow for single tooth immediate implant placement.@*Methods@#This pilot study was a prospective within-subjects design. Thirteen consecutive patients were included and diagnosed with untreatable single incisor or premolar with fine general and local anatomical conditions. The trial was conducted at Department of Implantology, Peking University School and Hospital of Stomatology, Beijing, between January 2016 and June 2016. The teeth were extracted atraumatically and implants were immediately placed in the fresh sockets. Two screw-retained interim crowns were fabricated for the same site utilizing different workflows, a monolithic lithium disilicate (LS2) crown produced by CEREC (Sirona, Germany) chairside CAD/CAM system (CER group) and a manually fabricated resin crown utilizing conventional workflow (CONV group) respectively. The patients were blinded to the group allocation of the two interim crowns. After the clinical try-in for both crowns in a randomized sequence, the patients' level of satisfaction was assessed with a virtual analogue scale (VAS) questionnaire. The restorations chosen by patients themselves were seated in the implants by one experienced prosthodontist. The accuracy, aesthetic effect and clinical time consumption of both groups were compared. Statistical analyses were performed with the Wilcoxon signed rank test.@*Results@#All patients were treated with atraumatic tooth extraction, immediate implant placement using flapless surgery and immediate provisionalization in a single visit. The interim crowns of both groups could be fitted with or without slight adjustments. For each patient, the interim crown of CER group was chosen to be seated with a relatively higher VAS result. The white esthetic score (WES) results demonstrated no statistically significant difference between CER group (7.5±1.1) and CONV group (7.9±0.9) (P>0.05). The mean total work time was significantly different resulting in (131.9±5.0) min for CER group and (205.2±6.3) min(P<0.05). The major difference lied in the laboratory work time, resulting in (113.5±6.3) min for CER group which was significantly shorter than (185.6±6.6) min for CONV group. As for impression taking time, the CER group (7.5±0.8) min was significantly shorter than CONV group (11.7± 1.1) min (P<0.05). However, analysis for clinical adjustment time showed a significantly longer time for CER group [(11.0±2.1) min vs (8.0±2.8) min, P<0.05]. After 3-6 months of observation, the overall survival rate was 100%. Screw loosening occurred in 4 patients and was tightened again. No other major complication soccurred.@*Conclusions@#The full digital workflow utilizing CEREC chairside CAD/CAM system to fabricate interim crowns after immediate implant placement in one single visit was feasible. It was more time-efficient and could effectively shorten the laboratory work time compared to the conventional workflow. Patients demonstrated high satisfaction and there was no statistical difference in WES results compared to the conventional workflow. Favorable clinical outcomes were gained in this short-term follow-up study.

Evaluation of alveolar ridge reconstruction and esthetic result following immediate implant / 北京大学学报(医学版)

Objective:To evaluate the bone alteration subject to remodeling and analyze the esthetic result following immediate implant placement of incisors.Methods:In this study,20 patients (1 3 women,7 men)were involved,who needed implants for incisors of maxilla.The patients received 23 im-mediate implants totally.On the day of surgery and 6 months after the implants were placed,Cone beam CT (CBCT)was taken.The thickness of the alveolar ridge and the vertical change of marginal bone levels onthe mesial and distal aspects of theimplants were measured using the computer software (Planme-caRomexis Viewer 3.6.0.R).The evaluation of esthetic result by labial convexity score (LCS)and pa-pilla index score (PIS)were analyzed pre-operation and one year after the final crown was delivered.The statistics with paired-t test for the measurement data and Willcoxon test for rating data were done by SPSS 20.0.Results:The survival rate in the two-year follow-up was 1 00%.The measuring point 1 (MP1 ), MP2,MP3 and MP4 (0,2,4,6 mm apical to the implant platform,respectively)got significant altera-tions after 6 months of the follow-up.These differences were statistically significant (P<0.05 ).The major alteration happened at MP1 and MP4,which got (-0.89 ±2.06)mm and (-0.75 ±1 .28)mm reduction of the alveolar,respectively.The marginal alveolar ridge resorption was (-0.42 ±1 .24)mm and(-0.91 ±1 .96)mm for Ankylos System and Replace System,respectively,and the difference was not statistical significant .The esthetic results were quite acceptable.Before treatment,1 8 incisors rated 3 for LCS,and 2 incisors rated 4 for LCS;after final restoration,only 5 incisors rated 3 for LCS,and 1 4 incisors rated 2 for LCS.Before treatment,1 5 incisors rated 3 for PIS;after final restoration,1 3 incisors rated 3 for PIS.There was no statistically significant difference for the PIS pre-operation and 1 year after final restoration,while there was statistically significant negative change for LCS.Conclusion:Even fol-lowing the proper surgical technique,the alveolar ridge wall still can’t be maintained after immediate im-plant placed in fresh socket of incisors.The inter-dental papilla could be well maintained,while due to the remodeling of labial bone,labial convexity will inevitably collapse.Therefore immediate implant still has esthetic risk.

Clinical evaluation of“All-on-Four”provisional prostheses reinforced with carbon fibers / 北京大学学报(医学版)

Objective:To assess the clinical effects of carbon fiber reinforcement on the“All-on-Four”provisional prostheses.Methods:Provisional prostheses were divided into control group and carbon fiber reinforcing group according to whether carbon fiber reinforcement was used in the provisional prostheses base resin.In our study,a total of 60 patients (32 males and 28 females)with 71 provisional prostheses (28 maxilla and 43 mandible)were enrolled between April 2008 and December 201 2 for control group;a total of 23 patients (1 3 males and 1 0 females)with 28 provisional prostheses (9 maxillas and 1 9 mandi-bles)were enrolled between January 201 3 and March 201 4 for carbon fiber reinforcing group.The infor-mation of provisional prostheses in the patients was recorded according to preoperative examination.We used the date of definitive prosthesis restoration as the cut-off point,observing whether fracture occurred on the provisional prostheses in the two groups.Additionally we observed whether fiber exposure occurred on the tissue surface of the provisional prostheses and caused mucosal irritation.The interface between the denture base resin and the fibers was examined using scanning electron microscopy (SEM).Results:The age [(57.3 ±1 0.1 )years vs.(55.1 ±1 1 .4)years],gender (32 males and 28 females vs.1 3 males and 1 0 females),maxilla and mandible distributions (28 maxillas and 43 mandibles vs.9 maxillas and 1 9 mandibles),the number of extraction jaws (46 vs.23 ),the average using time [(7 .8 ±1 .3 ) months vs.(7 .5 ±1 .1 )months],and the opposing dentition distributions of provisional prostheses of the patients showed no significant differences between the control and reinforcing groups.There were 21 (29 .6%)fractures that occurred on the 71 provisional prostheses in the control group;there was no frac-ture that occurred on the 28 provisional prosthesesin the carbon fiber reinforcing group.The fracture rate of the carbon fiber reinforcing group was significantly lower than that of the control group (P=0.001 ). No carbon fiber exposure and mucosal irritation were observed from clinical examination.SEM revealed relatively continuous contact between the fiber and acrylic resin,and the resin particles adhered on the surface of the carbon fibers.Conclusion:The addition of carbon fibers between abutments placed on“All-on-Four”provisional fixed denture base resin may be clinically effective in preventing “All-on-Four”denture fracture and can provide several advantages for clinical use.

A novel technique to preserve the alveolar ridge width following tooth extraction in the maxillary frontal area / 北京大学学报(医学版)

Objective:To introduce a novel ridge preservation technique with micro-titanium plate avoiding the use of bone grafting materials,and evaluate the potential horizontal bone preservation effect of this new technique,applied on single maxillary central incisors after tooth extraction for future implant restoration.Methods:Nine patients (six women and three men),mean age (26.0 ±5.7)years(from 1 8 to 34 years)referred to the Department of Oral Implantology,Peking University School and Hospital of Stomotology,were selected and diagnosed with unsalvageable single middle incisor with fine general con-ditions,no signs of acute local inflammation,no ongoing or previous periodontitis,healthy neighboring teeth and intact buccal bone walls.Tooth extraction,delayed implant placement and implant-supported single crown restoration were selected as treatment plan.The teeth were extracted atraumatically with lo-cal anesthesia,followed by a reflection of a minor flap to exposed 2-3 mm of the buccal bone plate.Af-ter that,a micro-titanium plate was trimmed and bended to fit the convexity of the labial bone and fixed by two mini pins with intent to support the labial soft tissue.The flap was then repositioned over the micro titanium plate and secured with two single sutures.No bone grafting materials or releasing incisions were needed.The sockets were left to heal without any intention of primary wound closure.Cone-beam compu-ted tomographic (CBCT)scans were obtained before and four months after tooth extraction.Horizontal ridge widths were measured with CBCT software,and the preservation effects were calculated and recor-ded by the percentage of horizontal ridge alteration.Results:The nine extraction sockets were healed un-eventfully.The average socket width before extraction was (7.51 ±0.48)mm (6.92-7.82 mm).The average alveolar ridge labial-palatal width at the control point of the edentulous area was (6.81 ±0.44) mm (6.04-7.38 mm)4 months after tooth extraction,the mean percentage of ridge width preserved was 90.87%±2.91%(87.28%-95.60%).Conclusion:This novel ridge preservation method by the usage of a micro-titanium plate did not interfere with the natural socket healing process,and at the same time,largely preserved the width of alveolar ridge without any bone grafting procedures.Long term results remain to be seen.

Application value of biochemical and immunological indicators in Lee′s classification of IgA ;nephropathy / 中华检验医学杂志

Objective To analyze the differences of biochemical and immunological indicators in gender or Lee′s classification of IgA nephropathy ( IgAN) to provide laboratory evidence for clinical diagnosis and treatment of IgAN.Methods Retrospective cohort study.The information of biochemical and immunological indicators of 213 in-hospital patients which were admitted in Chinese PLA General Hospital in June to December, 2012.The data were collected and analyzed with t-test, non-parameter analysis, Pearson correlation analysis, ROC curves analysis and Logistic regression analysis according to gender or Lee′s classification ( Lee′s≤3 group and Lee′s>3 group).Results In this study, the average age and sex ratio of patients with IgAN was ( 35.0 ±10.6 ) years old and 2.04∶1.00.T-test and non-parameter analysis indicated homocysteine(HCY), immunoglobulin E (IgE), immunoglobulin M (IgM), prealbumin (PA), ceruloplasmin ( CP) ,α1-acidoglycoprotein(α1-AGP) , albumin ( Alb) ,α2-globulin(α2-G) andγ-globulin (γ-G) had significant difference in gender (P<0.05).And cystantin-C (CYS-C), HCY, complement 4 (C4),β2-microglobulin(β2-MG), PA, α1-AGP, α1-globulin(α1-G), immunoglobulin G (IgG), IgM and transferrin ( TF ) had significantly different in Lee′s classification ( P<0.05 ).ROC curves analysis showed that the areas under curves of CYS-C andβ2-MG were 0.891 and 0.839 respectively;the sensitivity was 90.2%and specificity was 75.3% when cutoff value of CYS-C was 1.56 mg/L; the sensitivity was 80.3%and specificity was 78.8% when cutoff value of β2-MG was 0.275 mg/dl.Logistic regression analysis showed that CYS-C ( OR: 31.380, 95% CI: 10.808 -91.113, P=0.000 ) and HCY ( OR:1.035, 95%CI:1.002-1.069, P=0.040) were introduced into the model after twice variable selections.ROC curve of CYS-C combined with HCY for classifying Lee′s classification showed that the sensitivity, specificity, Jorden index and AUC were 0.843, 0.862, 0.705 and 0.894 ( P=0.000 ) , respectively.Conclusions CYS-C,β2-MG, PA and HCY were valuable indicators for Lee′s classification.CYS-C andβ2-MG had high correlation with Lee′s classification, which indicated that these two tests were related to the severity of IgAN.CYS-C combined with HCY could improve the diagnostic efficiency of IgAN Lee′s classification.Combination of biochemical and immunological indicators could improve the accuracy of Lee′s classification and provide effective laboratory evidence for clinical treatment of IgAN.

Application of spark erosion technology in manufacture of implant prosthesis / 北京大学学报(医学版)

Objective:To evaluate the influence of the implant-supported porcelain bridges made from non-precious metals using spark erosion techniques, and to discuss the feasibility and details of making the implant restoration by spark erosion technique.Methods: The study included 12 patients ( 9 males and 3 females) with 92 units implant-supported non-precious porcelain bridge from Sep.2011 to Feb. 2013.All the patients received implant treatment in Department of Oral Implantology, Peking University School and Hospital of Stomatology.The total of 52 implants, were from Nobel Biocare implant system, Camlog implant system and Ankylos implant system.The implant analogs were connected in sequence with a copper wire to guarantee conductivity.The implant electrodes represented one electrode and the superstructure the other.During spark-erosion machining, the cast holding the implant electrodes and the prosthetic framework were moved toward one another, causing an electrical erosion of the protruding ele-ments.Results:After the spark-erosion machining, the minimum gap between the framework and abut-ment was 0.21 mm, which was two units bridge.The maximum was 2.59 mm, which was 11 units bridge with 6 implants.The average gap was 0.68 mm.After the spark-erosion machining, the bridge fitted well with the passive position stability.Conclusion: The method of making implant-supported non-precious porcelain bridge reduces costs on patients.Spark erosion has the potential to provide implant framework with an excellent fit.The patients are satisfied with the clinical results.