[Rate and risk factors of tip displacement of umbilical venous catheterization at different indwelling time points in preterm infants].

Objectives: To investigate the rate and risk factors of tip displacement of umbilical venous catheterization (UVC) in preterm infants. Methods: This was a multicenter cohort study. Study population were preterm infants admitted to 44 tertiary hospitals in China between October 2019 and August 2021. Demographic information, general clinical data, UVC indwelling conditions and related complications were collected. The primary outcome was the rate of UVC tip displacement. The observation time points were 2 d and 7 d after UVC. They were grouped according to UVC displacement, gestational age, and birth weight. Binary Logistic regression was used to analyze the risk factors of UVC tip displacement. Results: The 2 086 preterm infants had a gestational age of (29.9±2.3) weeks and a birth weight of (1 248±298) g. There were 1 106 male preterm infants (53.0%). The rate of UVC displacement at 2 d and 7 d were 34.6% (721/2 086) and 33.6% (494/1 470), respectively, with no statistically significant difference (χ2=0.35, P=0.533). Univariate analysis indicated that male infants, small gestational age, low birth weight and small catheter diameter were all risk factors for UVC tip displacement at the 2 d time point (all P<0.05). Multivariate analysis showed that small catheter diameter was an independent risk factor for tip displacement at both 2 d (OR=0.47, 95%CI 0.34-0.66) and 7 d (OR=0.39, 95%CI 0.25-0.59) time points (both P<0.001). Conclusions: The rate of UVC tip displacement is high in preterm infants. It should be avoided to deliberately select a small diameter catheter for UVC, and pay attention to the imaging monitoring of the tip position after UVC.

[Literature data mining on the current research status of uveitis in China].

Objective: To analyze the current research status of uveitis in China. Methods: It was a bibliometric analysis study. Using search formulas covering uveitis and its multiple subtypes, uveitis-related literature in English with publication dates from 2013 to 2022 was retrieved in Web of Science core databases through certain search strategies. This study used the latent Dirichlet allocation (LDA) algorithm to build topic models and analyzed the trends of research topics in recent years. Bibliometric analysis was used to analyze and visualize the bibliometric indicators (e.g., number of publications, citations, and H-index) of the included literature using tools such as VOSviewer software. Results: Over the past decade, China has published 1 657 papers on uveitis, ranking second globally. However, there is still room for improvement in terms of the H-index (58) and citation (12.28 per publication). Countries such as the USA (43.04%) and the United Kingdom (62.54%) were engaged in more international collaboration. We identified ten optimal LDA topics for uveitis literature in China such as immunotherapy, Behçet's disease, and Vogt-Koyanagi-Harada syndrome. Research on uveitis in China was mostly published in Ocular Immunology and Inflammation (92). Conclusions: China has made remarkable progress in uveitis research. Nonetheless, there is still untapped potential to enhance our global academic influence. It is encouraged to promote international collaborations, harness our expertise in areas like Behçet's disease and VKH syndrome, and publish our scientific achievements in high-impact journals.

[Electromyographic signals and the starting threshold voltage of orbicularis oris muscle in healthy rhesus monkeys].

Objective: To investigate the characteristics of electromyography (EMG) signals and the starting threshold voltages of the orbicularis oris muscles (OOM) in healthy rhesus monkeys under different muscle movement conditions. Methods: The EMG signals and the starting threshold voltages at different time points in 4 healthy rhesus monkeys were acquired and recorded with EMG device and evoked potentiometer. The voltage amplitude variation of EMG signals was analyzed, and the voltage amplitude range of EMG signals at the beginning of OOM contraction was established. The data were statistically analyzed by one-way ANOVA. Results: The EMG of OOM in healthy monkeys in the quiet, natural and continuous mouth-closed state was linear and relatively stable, and the absolute value fluctuated between 15 and 50 µV. The EMG waveform increased rapidly during the natural lip contraction movement, and its amplitude fluctuated greatly, with the highest absolute value of the peak value reaching hundreds of microvolts. The amplitude of EMG induced by continuous mouth closure was more than thousands of microvolts. There was no significant difference in EMG amplitudes of OOM in the healthy rhesus monkey under quiet and continuous lip closure at different time points (P>0.05). There was no significant difference in threshold voltages in the state of natural lip contraction of bilateral OOM at different time points (average range: 57.17-57.47 µV) in the healthy rhesus monkeys (P>0.05). There was no significant difference in threshold voltages of OOM induced by bilateral OOM at different time points(average range: 55.38-55.99 µV) in the healthy rhesus monkeys(P>0.05). There were significant differences in the absolute values of EMG amplitudes of OOM between the three lip movement modes: (30.67±8.72) µV in quiet and natural continuous lip closure (475.12±54.72) µV in natural lip contraction, and (921.22±312.79) µV in the induced persistent lip closure, with t values of -8.48, -9.35 and -5.01 respectively, all P<0.001. Conclusions: The EMG signals of OOM show different characteristics under different muscle movement conditions, which can be used as a basis for computer to judge and recognize the movement conditions of OOM. The upper limits of the EMG threshold voltage values of OOM under different motion states are 55-60 µV.

Prediction of ameloblastoma recurrence using random forest-a machine learning algorithm.

The purpose of this study was to investigate whether ameloblastoma with a high likelihood of recurrence can be predicted using random forest model, a machine learning algorithm. Data were collected from patients treated for ameloblastoma between 1999 and 2019 at the University of Hong Kong. Fourteen clinical parameters were used to grow the decision trees to classify patients with or without ameloblastoma recurrence in the follow-up period. The random forest algorithm was computed 100 times in the training cohort (n = 100) and verified in the testing cohort (n = 50). The receiver operating characteristic curve (ROC) and area under the curve (AUC) were used as the performance measurement of separability. One hundred and fifty patients (76 female, 74 male) were recruited, with a mean follow-up time of 103 months. Recurrence occurred in a total of 25 cases (16.7%) over the 20-year period. The AUC were calculated for the median and mean ROC curves; these were 0.777 and 0.825, respectively. The results showed that random forest model was able to predict recurrence of ameloblastoma with reliable accuracy. The four most important variables influencing ameloblastoma recurrence were the time elapsed from treatment, initial surgical treatment, tumour size, and radiographic presentation. This study provides insights into the detection of high-risk patient groups to monitor recurrence. Further application of random forest to other diseases could greatly benefit clinical decisions.

Effects of surface roughness on the time-dependent wear performance of lithium disilicate glass ceramic for dental applications.

OBJECTIVES: Purpose of the present study was to evaluate the effect of surface roughness on the time-dependent wear performance of lithium disilicate (LD) glass-ceramic. METHODS: Friction pairs (pin and disk specimens) were prepared by IPS e.max® Press lithium disilicate glass-ceramic. The lateral faces of friction pairs (N = 12) were grinded with silicon carbide papers, and 6 friction pairs were polished with a 0.25 µm diamond suspension after grinding. The friction pairs were tested for wear performance using a pin-on-disk tribometer with 10 N for 1.02 × 106 wear cycles in artificial saliva. Wear analysis of the pin and disk was performed with a 3D profilometer. The microstructure and worn surface morphology were examined with scanning electron microscopy. One-way analysis of variance and Tukey's post-hoc pairwise comparison were used to analyze the wear data. RESULTS: The two group LD friction pairs presented strong time-dependent wear performance. The polished group (GP) exhibited a high wear rate and extensive surface wear during 0-1 × 105 cycles (running-in wear stage). The wear rate, height loss and surface roughness were obviously lower than those of grinded group (GG) in running-in wear stage. However, these wear parameters were similar during the steady wear stage. The worn surface topographies of the pin and disk in GP were smoother at the same cycle before the GG entering the steady wear stage. CONCLUSION: Running-in, which means the initial stage of wear process, is a critical period to determine the final wear loss and surface degradation, when compare the wear behavior of lithium disilicate ceramic with different initial surface states. Ceramic layer with smooth contact area leads to low wear rate and short running-in wear stage.

[Application of septal extension graft with autogenous septal cartilage and auricular cartilage in rhinoplasty].

Objective: To explore the feasibility of reconstruction of nasal tip with septal cartilage and auricular cartilage. Methods: From September 2018 to October 2019, 17 patients (two males and fifteen females) with low noses underwent rhinoplasty under general anesthesia. The age of the patients ranged from 19 to 39, with an average of 27 years old. Among them, all the 17 cases were primary rhinoplasty. During the operation, autologous nasal septum cartilage was used as septal extension graft to extend the caudal septum, and the auricular cartilage was used to enhance the stability of the strut and to elevate the tip for adjusting the shape of nose by making into spreader graft, columellar strut graft, derotation graft and onlay graft. The nasal dorsum was filled with polytetrafluoroethylene. Digital scanning technology was used to evaluate the nasal structure before and after operation. SPSS 22 software was used to analyze the data with paired t-test. Results: The follow-up was from 6 to 12 months, with an avaerge of 7.6 months. Seventeen patients were satisfied with postoperative nasal morphology and height. There was no infection, prosthesis displacement, skin flap necrosis, no auricle deformation and other complications. Statistical software SPSS 22 performed paired t-test on the preoperative and postoperative data obtained by digital technology: postoperative nasal length and nasal tip protrusion increased compared with that before surgery, and it was statistically significant(length:(3.60±0.77)mm, tip protrusion:(3.61±0.64)mm, t value was -19.203 and -23.132 respectively, both P<0.001). The nasolabial Angle was smaller than that before surgery, and the data were statistically significant(3.40°±2.11°,t=6.635, P<0.001). Conclusion: The nasal tip and nasal septum extension complex constructed by autogenous nasal septal cartilage combined with auricular cartilage can increase the length of nasal tip, increase the height of nasal tip and reduce the angle of nasolabial angle.

Improved reliability of wear performance for a fluorapatite veneering porcelain by ion-exchange strengthening and toughening.

OBJECTIVES: Purpose of the present study was to explore the improvement of wear performance for a nano fluorapatite veneering porcelain by ion-exchange. METHODS: Bar and disk specimens were prepared by IPS e.max Ceram as the nano fluorapatite veneering porcelain. Ion-exchange was performed in a melted KNO3 bath at two temperatures for different time-periods. After the ion-exchange, the bars were tested for flexural strength, surface Vickers hardness and HIF toughness, the disks were tested for wear performance paired with zirconia antagonist using a pin-on-disk tribometer with 10 N for 70✕104 wear cycles in artificial saliva. Wear analysis of the porcelain and zirconia was performed with a 3D profilometer. The microstructure and worn surface morphology were examined with scanning electron microscopy. One-way analysis of variance and Tukey's post-hoc pairwise comparison were used to analyse the wear data. RESULTS: The nano fluorapatite veneering porcelain before ion-exchange presented strong time-dependent wear behavior. Furthermore, wear rate of the original porcelain exhibited a very large standard deviation in the running-in wear stage, which was correlated with highly inhomogeneous distribution of the characteristic fluorapatite crystals in the microstructure. After ion-exchange at 350 °C and 380 °C, especially after the processing at 350 °C for 128 h, the wear rates of both running-in and steady wear stages could be significantly decreased. More importantly, the standard deviation of wear rate in the running-in wear stage could be remarkably reduced after the treatment. The improved reliability of wear performance was attributed to the strengthening and toughening effects of the ion-exchange processing. CONCLUSION: For the fluorapatite veneering porcelain, the ion-exchange protocol to obtain an ion-exchange layer with less stress relaxation and a considerable depth could strengthen and toughen the porcelain; as a result, the reliability of wear performance could be remarkably improved.

[Study on the matching feature of current parameters for inducing contraction of orbicularis oris muscle by artificial facial nerve in rabbit with peripheral facial paralysis].

Objective: To explore the optimal matching of the current parameters about artificial facial nerve (AFN) for inducing contraction of the orbicularis oris muscle (OOM) in rabbit with peripheral facial paralysis. Methods: According to the combinations of different stimulus parameters, at different time points, we used AFN to induce contraction of the affected side OOM of the paralyzed rabbit in waking state. We recorded the current amplitudes of the threshold stimulation and peak stimulation under each combination, then compared the total charge of the stimulus consumption under different combinations. Results: Compared the total stimulus charge consumption of the AFN threshold stimulation and that in the peak stimulation respectively under different stimulus frequency and pulse width matching combinations, we found that the frequency, the pulse width and the interaction of the frequency and pulse width among different groups could affect the total charge, the differences were statistically significant (P<0.05). Conclusions: When AFN stimulus frequency is 60 Hz and the stimulus pulse width is 100 µs, the output current intensity is relatively lowest and the total consumed charge is the lowest under the premise of effectively inducing the paralytic side OOM contraction. Thus we recommend this stimulus parametric combination as the optimal combination for meeting the low power consumption of AFN.

[Restoration of orbicularis oculi muscle function with totally implanted artificial facial nerve].

Objective: To investigate the effect of the artificial facial nerve on the restoration of orbicularis oculi muscle function for unilateral peripheral facial paralysis in rabbit. Methods: Artificial facial nerve was implanted into the rabbit with unilateral peripheral facial paralysis between January 2018 and May 2019. At different time points after operation, the affected orbicularis oculi muscles' stimulation closure threshold and the synchronism about the motion of the two sides of orbicularis oculi muscles were monitored. T test was used with SPSS 13.0 software. Results: There was no significant difference in the closure threshold of the orbicularis oculi muscle on the 7th and 28th days after artificial facial nerve implantation (P>0.05). The synchronism of the normal side eye closing movement triggered the affected orbicular oculi muscle movement with the artificial facial nerve was up 19/20 to 20/20 at different times. Conclusions: The artificial facial nerve system had the features of stable working condition and high synchronizing effect for stimulating movement. It could restore the closed eye function in animals with peripheral facial paralysis animals and had great clinical application prospects.

Topical Fluoride to Prevent Root Caries: Systematic Review with Network Meta-analysis.

The aim of this systematic review and network meta-analysis was to summarize the direct and indirect clinical evidence on the effectiveness of professionally applied and self-applied topical fluorides in preventing dental root caries. Controlled clinical trials with any follow-up duration were included. MEDLINE, PubMed, Embase, Scopus, and Cochrane Library were searched. Two reviewers independently carried out the selection of studies, data extraction, risk-of-bias assessments, and assessment of the certainty in the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Fixed effects model and frequentist approach were used in the network meta-analyses. Nine clinical trials involving 4,030 participants were included. Five professionally applied and 7 self-applied topical fluoride agents or combinations were included in the meta-analyses. Compared to control group, 38% silver diamine fluoride solution, 5% sodium fluoride varnish, and 1.2% acidulated phosphate fluoride reduced root caries increment after 2 y (ranging from 0.59 to 0.85 mean decayed or filled root [DF-root]). Fluoride mouth rinse and fluoride toothpaste, used alone or in combination, reduced root caries increment after 1 y (ranging from 0.29 to 1.90 mean DF-root). Among the professionally applied topical fluorides reviewed, an annually applied 38% silver diamine fluoride (SDF) solution combined with oral health education is most likely to be the most effective in preventing dental root caries. Among the reviewed self-applied topical fluoride methods, daily use of a 0.2% sodium fluoride (NaF) mouth rinse is most likely to be the most effective, followed by 1100 ppm to 1500 ppm fluoride toothpaste plus 0.05% NaF mouth rinse, and 1100 ppm to 1500 ppm fluoride toothpaste.

[Comparative study of ultrasound-guided percutaneous microwave ablation and surgical resection for colorectal cancer with liver metastasis].

Objective: To study the clinical efficacy of ultrasound-guided percutaneous microwave ablation and surgical resection for liver metastases from colorectal cancer. Methods: Retrospective analysis of 184 patients with liver metastases from colorectal cancer in Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology from January 2012 to June 2017.Percutaneous microwave ablation or surgical resection for liver metastases were selected under ultrasound guidance. Subgroup analysis was performed according to the treatment of liver metastases. There were 98 patients in the microwave-only group (56 males and 42 females, aged (59±11) years) and 86 cases in the surgery-only group (56 males and 30 females, aged (56±11) years). The baseline data of the two groups were compared, and the results showed that the size of the metastatic lesions in the microwave-only group was smaller than that in the surgery-only group, and the remaining data didn't had statistical differences.The survival time of the two groups of patients was analyzed separately.According to the size of the metastases, the metastases were divided into groups with a diameter of<3 cm and a group of ≥3 cm. The survival time of patients in the microwave-only group and the surgery-only group were analyzed respectively.According to the different primary tumor grades of colorectal cancer, the survival time of patients in the simple microwave-only group and the surgery-only group in the primary tumors Duck A, Duck B, and Duck C were analyzed. Results: In the microwave-only group, the overall survival rates at 1, 3, and 5 years were 100%, 50.9%, and 20.9%; in the surgery-only group, the overall survival rates at 1, 3, and 5 years were 100%, 42.8%, and 20.8%, respectively. There was no significant difference in overall survival between the groups (P=0.972).Metastatic focus diameter ≥3 cm: the overall survival rates of 1, 3, and 5 years with microwave-only were 100%, 65.4%, and 12.1%; the overall survival rates of 1, 3, and 5 years with surgery-only were 100%, 59.5%, and 30.9%. There was no significant difference in overall survival between the groups (P=0.067). The long-term survival rate of the surgery-only group was greater than that of the microwave-only group (P=0.018).Metastasis diameter<3 cm: there was no significant difference in overall survival between the surgery-only group and the microwave-only group (P=0.103).In the treatment of Duck B and C liver metastases of primary colorectal cancer, there was no significant difference in overall survival between microwave alone and surgery alone (P=0.376, P=0.385).Multivariate analysis showed that the size of colorectal cancer metastases was an independent risk factor affecting the prognosis of patients with colorectal cancer liver metastases. Conclusions: Percutaneous microwave ablation has a good effect on colorectal cancer liver metastases and has a similar survival prognosis as surgery.For livers with color ≥ 3 cm in colorectal cancer, the long-term survival rate of the surgery-only group is greater than that of the microwave-only group.

[Clavien-Dindo classification of complications after complete mesocolic excision in laparoscopic radical resection of right hemicolon cancer and analysis on its influencing factors].

Objective: To investigate the Clavien-Dindo (CD) classification of complications after complete mesocolic excision (CME) in laparoscopic radical resection of right-sided hemicolon cancer and its influencing factors. Methods: A retrospective case-control study was performed. Inclusion criteria: (1) the adenocarcinoma located at colon from cecum to hepatic flexure; (2) laparoscopic right hemicolectomy with CME was completed. Exclusion criteria: (1) patients had severe organ dysfunction before operation; (2) tumor invaded adjacent organs or developed distant organ metastasis; (3) emergency surgery; (4) failure of laparoscopic surgery, and conversion to laparotomy; (5) without complete clinical data. Finally, clinical data of 141 patients in our hospital form March 2015 to February 2019 were retrospectively analyzed. CD grading standard was used to evaluate postoperative complications. Univariate and multivariate logistic regression analyse were used to analyze the factors that might affect the complications. Survival analysis was conducted by grouping the indicators with statistically significant difference in multivariate analysis. Kaplan-Meier method was used to draw the survival curve and log-rank test was used to analyze the difference. Results: Of the 141 patients, 89 were male and 52 were female with mean age of (61.8±11.0) years. All the operations completed successfully. A total of 37 postoperative complications were developed in 26 (18.4%) patients had postoperative 37 cases of complications, mainly including 7 delayed incision healing, 6 diarrhea, and 5 respiratory dysfunction. According to CD classification standard, grade I, II, and IV a complication rates were 40.5% (15/37), 56.8% (21/37), and 2.7% (1/37) respectively. Univariate analysis showed that age ≥ 65 years (χ(2)=4.338, P=0.037), BMI ≥ 28 kg/m(2) (χ(2)=5.971, P=0.015), and preoperative hemoglobin < 100 g/L (χ(2)=3.985, P=0.046) were risk factors of postoperative complications. Multivariate analysis testified that age ≥ 65 years (OR=7.991, 95%CI: 2.203 to 28.983, P=0.002) and body mass index (BMI) ≥ 28 kg/m(2) (OR=4.231, 95%CI: 1.034 to 17.322, P=0.045) were independent risk factors for complications after laparoscopic CME surgery for right-sided hemicolon cancer. All the patients were followed up for median time of 24 (1-48) months. The log-rank test showed that there were no significant differences in the cumulative survival rate between patients of age < 65 years and age ≥ 65 years (χ(2)=0.986, P=0.321), and between those with BMI < 28 kg/m(2) and BMI ≥ 28 kg/m(2) (χ(2)=0.370, P=0.543). Conclusions: The main complications after CME in laparoscopic radical resection of right hemicolon cancer are CD grade I and II. Elderly and obesity are independent risk factor for postoperative complications. Before the operation, reasonable preventive measures should be taken for the elderly and the obese in order to reduce postoperative complications.

[Study on the method of microelectrodes implantation of artificial facial nerve prosthesis in closed mouth of orbicularis oris muscle in monkeys with facial nerve paralysis].

Objective: To explore the optimal method of microelectrode implantation that can produce efficient mouth closure with microelectrode for orbicularis oris muscle (OOM) in rhesus monkeys with unilateral peripheral facial paralysis (UPFP) in order to provide basis for the research and development of artificial facial nerve prosthesis (AFNP). Methods: Right lateral peripheral facial paralysis model on four healthy rhesus monkeys (two males and two femles, aged 5-6 years, weighed 2.0-3.0 kg) were prepared. AFNP electric stimulation was used to induce closed-mouth reaction of the affected OOM with a one-way rectangular pulse, 50 Hz frequency and 0.2 ms pulse width in vitro. Around the affected lateral OOM, four stimulus electrodes implantation positions were selected at the upper lip (position A), the lower lip (position B), the connection with the corner of the mouth to the ipsilateral tragus (position C), and the horizontal line of the mouth angle (position D). According to the different implantation positions of three stimulation electrodes on the stimulation side of AFNP and the results of our previous study, six groups of microelectrode implantation methods were designed. In Group A, two microelectrodes were implanted at position A and one microelectrode was implanted at position B; in Group B, one microelectrode was implanted at position A, B and C respectively; in Group C, one microelectrode was implanted at position A and two microelectrodes were implanted at position B; in Group D, one microelectrode was implanted at position A, B and D respectively; in Group E, one microelectrode was implanted at position A, C and D respectively; in Group F, one microelectrode was implanted at position B, C and D respectively. The minimum stimulating current (threshold current) required for effective mouth closure were recorded. The threshold and peak current values were compared using one-way ANOVA and LSD-t multiple comparisons. Results: The microelectrodes of the AFNP stimulating side in Group E and F failed to induce a smooth mouth closure. The microelectrodes in A, B, C and D group induced smooth mouth closure. The threshold current value of OOM contraction on affected side in the Group A, B, C, and D were (1.35±0.05), (1.02±0.04), (1.40±0.04) and (1.10±0.02) mA, respectively (F=295.302, P<0.001), with the lowest value in Group B and there was significant difference between the current value in Group B and those in the other groups (all P<0.05). The peak current value of OOM contraction on affected side in the four groups were (3.95±0.02), (2.95±0.03), (3.99±0.05) and (3.51±0.01) mA, respectively (F=1 014.985, P<0.001). Group B showed the best lip-closure morphology observed with naked eyes. Conclusions: When three output microelectrode of the AFNP stimulated side are separately imbedded into the upper lip, the lower lip and the connection with the corner of the mouth to the ipsilateral tragus, AFNP can sufficiently induce closed-mouth reaction. These positions are suitable as priority options microelectrodes implantation positions for the microelectrodes of the AFNP stimulated side.

Ten-year clinical evaluation of posterior fixed-movable resin-bonded fixed partial dentures.

OBJECTIVES: Two-unit cantilevered resin-bonded fixed partial dentures (RBFPDs) offer long-term retention for anterior and premolar-sized spans. At this center, molar and longer spans have been restored with fixed-movable (FM) RBFPDs to overcome the lower retention rates of fixed-fixed RBFPDs. This retrospective study aimed to evaluate the long-term longevity and the patient-reported outcomes of posterior FM-RBFPDs. METHODS: Posterior FM-RBFPDs that had been inserted at least five years were reviewed. Survival was "retention of the original prosthesis in mouth" and success was "survival of prosthesis and absence of complications requiring treatment intervention". Prosthesis location, number of units, insertion year, tooth/teeth replaced and operator experience were collected. Patients' acceptance to FM-RBFPDs were assessed using prosthesis satisfaction questionnaire and Oral Health Impact Profile (OHIP-49). Results were analyzed using log-rank and cox-regression tests at significance level α = 0.05. RESULTS: One-hundred-and-one prostheses were examined. The mean observation time was 126.4 ±â€¯32.2 months. Thirty-six (35.6%) and 63 (62.4%) FM-RBFPDs were rated as success and survival respectively. Prostheses inserted after year 2001 (n = 69) experienced 42.0% (n = 29) success and 75.4% (n = 52) survival, and its survival rate was significantly better than those inserted in or before 2001 (p = 0.01). Five- and ten-year cumulative survival probability of FM-RBFPDs inserted after year 2001 were 82.3% and 74.1% respectively. The most frequent complications were debonding among 34 (33.7%) prostheses. Patients' acceptance were high. CONCLUSIONS: More recently inserted prostheses showed improved longevity and patients' acceptance to posterior FM-RBFPDs were high. CLINICAL SIGNIFICANCE: Fix-Movable RBFPDs are a viable tooth replacement option in the posterior region.

Risk factors for recurrence of ameloblastoma: a long-term follow-up retrospective study.

Ameloblastoma is a benign odontogenic tumour showing locally aggressive characteristics. This retrospective study was performed to investigate the long-term treatment outcomes of ameloblastoma and to evaluate the risk factors for recurrence. The study was conducted in the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, the University of Hong Kong and covered the years 1990-2017. Patient demographic data, radiographic pattern and findings, clinical findings, tumour site and size, World Health Organization classification, treatment modality, histological pattern, duration of follow-up, and timing of recurrence were recorded and analyzed. The potential risk factors were analyzed by Kaplan-Meier and Cox regression tests. The cases of a total of 128 patients were reviewed; 65 were male and 63 were female. The mean follow-up period was 117 months. The 5-, 10-, and 15-year recurrence rates were 9.3%, 17.6%, and 24.4%, respectively. Kaplan-Meier and Cox regression tests showed that recurrence was significantly associated with radiographic pattern, tumour size, and treatment modality. Multiple regression analysis for these three variables demonstrated that treatment modality was the only independent prognostic factor for recurrence. This study showed that radical resection is the only significant factor for a low recurrence rate of ameloblastoma and patients require long-term follow-up for late-onset recurrence.

Influence of apical preparation size and irrigation technique on root canal debridement: a histological analysis of round and oval root canals.

AIM: To examine the debridement of round and oval root canals prepared to two apical sizes with and without ultrasonically activated irrigation. METHODOLOGY: Mandibular premolars with round (n = 48) and oval (n = 48) root canals were pair-matched after microCT scanning and randomly divided into two experimental groups (n = 20): group 1, rotary NiTi to size 20, .04 taper; group 2, rotary NiTi to size 40, .04 taper. Specimens were subdivided into two subgroups (n = 10): subgroup A, syringe and needle (SNI); subgroup B, ultrasonically activated irrigation (UAI). Untreated canals (eight oval and eight round) served as controls. Specimens were processed for histological evaluation for measurement of the remaining pulp tissue and debris (RPT), and the perimeter percentage of root canal area untouched by the instruments (PRAU). Following assessment of normality, multiple-way anova models were used to study the effects of preparation size, irrigation technique and canal cross-sectional shape, and their interactions on the RPT and PRAU (α = 0.05). RESULTS: All experimental groups had significantly less RPT than the control (P < 0.05). Both the preparation size (20 vs. 40) and the irrigation technique (SNI vs. UAI) had a significant effect on RPT (P = 0.006 and P < 0.001, respectively). Groups irrigated with SNI always had significantly greater RPT than those irrigated with UAI, irrespective of the preparation size (P < 0.001). Canals prepared to size 20 had significantly greater RPT than those with size 40 in the SNI subgroup (P < 0.001), but there was no significant difference in the UAI subgroup (P = 0.481). CONCLUSIONS: Root canals prepared to a larger size (40) were cleaner than those prepared to a smaller size (20), when irrigation was performed with a syringe and needle. When the irrigant was ultrasonically activated, smaller preparations resulted in canals that were as clean as larger preparations. This finding was common to both round and oval canals of freshly extracted premolars with vital pulp tissue.

Does the use of amoxicillin/amoxicillin-clavulanic acid in third molar surgery reduce the risk of postoperative infection? A systematic review with meta-analysis.

The objectives of this systematic review were to investigate the efficacy of amoxicillin/amoxicillin-clavulanic acid for reducing the risk of postoperative infection after third molar surgery and to evaluate the adverse outcomes in these patients, as well as in healthy volunteers. A systematic search of four databases was performed on May 26, 2017. Eleven studies qualified for the qualitative analysis and eight were found suitable for meta-analysis. The results suggest that both amoxicillin-clavulanic acid and amoxicillin significantly reduce the risk of infection after third molar extraction (overall relative risk (RR) 0.25, P<0.001). However, with the exclusion of randomized controlled trials with a split-mouth design (due to an inadequate crossover period after antibiotic treatment), only amoxicillin-clavulanic acid was found to be effective (RR 0.21, P<0.001). The risk of adverse effects was significantly higher in the amoxicillin-clavulanic acid group (RR=4.12, P=0.023) than in the amoxicillin group (RR 1.57, P=0.405). In conclusion, amoxicillin-clavulanic acid and amoxicillin may significantly reduce the risk of infection after third molar extraction. However, their use in third molar surgery should be viewed with caution, as recent clinical trials on healthy volunteers have shown evidence of the negative impact of amoxicillin use on bacterial diversity and antibiotic resistance.

The directional and non-directional associations of periodontitis with chronic kidney disease: A systematic review and meta-analysis of observational studies.

This systematic review aimed to assess the current evidence on the directional and non-directional associations of periodontitis with chronic kidney disease (CKD). Electronic search for observational studies on the association of periodontitis with CKD was performed in MEDLINE, EMBASE, PubMed, Open GREY and Cochrane library up to June 5, 2017. Two reviewers conducted study selection, data collection and assessment of methodological quality using the original and modified Newcastle-Ottawa Scale. Cohort, case-control and cross-sectional studies were included, which clearly defined periodontitis and CKD or reported acceptable clinical parameters of these 2 diseases in adults. Meta-analysis was employed to estimate the pooled odds ratio on the non-directional association and the incidence rate ratio (IRR) for the directional association. Among 2530 potential eligible articles, 47 were finally included. Most of them investigated a non-directional association of periodontitis with CKD, including 7 case-control studies and 38 cross-sectional studies; 24 studies had statistical analysis on the non-directional association and 75% of them reported significant results, which were supported further by the meta-analysis (random: odds ratio = 2.12, P < .001; χ2  = 25.74, I2  = 88.3%). None of the studies focused on the directional association of CKD (as the exposure) with periodontitis (as the outcome), whereas 2 retrospective cohort studies explored a directional association of periodontitis (as the exposure) with CKD (as the outcome) (random: IRR=2.10, P > .05; fixed: IRR=1.76, P < .05; χ2  = 4.65, I2  = 78.3%). Overall, the high heterogeneity of studies limits the significance of these results. There is substantial evidence on the non-directional association of periodontitis with CKD, while there are limited studies on the directional association. Well-designed prospective studies with longer follow-ups in representative communities are needed to clarify the directional association and enhance the quality of the evidence on this topic.

One versus two venous anastomoses in microsurgical head and neck reconstruction: a cumulative meta-analysis.

Venous compromise is still the most common cause of free flap failure. The use of two venous anastomoses has been advocated to reduce venous compromise. However, the effectiveness of this approach remains controversial. A systematic review and cumulative meta-analysis was performed to assess the effect of one versus two venous anastomoses on venous compromise and free flap failure in head and neck microsurgical reconstruction. A total of 27 articles reporting 7389 flaps were included in this study. On comparison of one versus two venous anastomoses, the odds ratio (OR) for flap failure was 1.66 (95% confidence interval 1.11-2.50; P=0.014) and for venous compromise was 1.50 (95% confidence interval 1.10-2.05; P=0.011), suggesting a significant increase in the flap failure rate and venous compromise rate in the single venous anastomosis group. These results show that the execution of two venous anastomoses has significant effects on reducing the vascular compromise and free flap failure rate in head and neck reconstruction.