[Efficacy analysis of autologous facet joint bone block in lumbar interbody fusion of osteoporosis patients].

OBJECTIVE: To compare and analyze the feasibility of autologous facet joint bone block as an alternative to polyetheretherketone (PEEK) cage in lumbar intervertebral fusion surgery for patients with osteoporosis. METHODS: From December 2018 to June 2021, the case data of patients with osteoporosis (T value ≤ -2.5 on dual energy X-ray bone density) who underwent posterior lumbar interbody fusion in the Fourth Medical Center, Chinese PLA General Hospital were retrospectively reviewed. All the cases were followed up for no less than 12 months and were divided into two groups according to the differences of interbody fusion materials: the autologous facet joint bone block group (autogenous bone group) and the PEEK cage group (PEEK group). The general data [such as age, gender, body mass index (BMI), primary diagnosis, distribution of fusion segments, bone mineral density of lumbar (BMD), incidence of preoperative complications], the perioperative data (such as duration of operation, intraoperative blood loss, postoperative drainage, perioperative allogeneic blood transfusion rate), and the incidence of postoperative complications were compared between the two groups. Imaging parameters (disc height, lumbar lordosis angle, segment lordosis angle, segmental lordosis angle, disc height improvement rate, and fusion rate) and lumbar functional scores [visual analogue scale (VAS), Oswestry disability index (ODI), Japanese Orthopedics Association (JOA) score for lower back pain] were compared to evaluate the clinical efficacy between the kinds of intervertebral fusion materials 1 week, 3 months and 6 months postoperative and at the last follow-up. RESULTS: A total of 118 patients were enrolled, including 68 cases in the autogenous bone group and 50 cases in the PEEK group, there were no statistical differences in age, gender, BMI, primary diagnosis, distribution of fusion segments, BMD, incidence of preoperative complications, duration of operation, intraoperative blood loss, postoperative drainage, perioperative allogeneic blood transfusion rate, incidence of postoperative complications, all the preoperative imaging parameters and all the lumbar function scores between the two groups (P>0.05). Postoperative superficial surgical site infections occurred in 3 patients in the autogenous bone group and 2 patients in the PEEK group. At the last follow-up, 3 cases of intervertebral graft collapse occurred in the autogenous bone group and 5 cases in the PEEK group, 1 case of graft subsidence in the autogenous bone group and 1 case in the PEEK group. All the imaging parameters showed significant differences between postoperation and preoperation (P < 0.05), and all the imaging parameters showed significant differences between 1 week and 3 months postoperative in both groups (P < 0.05). The height, angle of fusion gap in the autogenous bone group were lower than those in the PEEK group 1 week postoperatively (P < 0.05), and the fusion gap height improvement rate in the autogenous bone group was lower than that in the PEEK group (P < 0.05). The cases in both groups started to show final fusion 3 months after surgery, and the fusion rate in the autogenous bone group was 75% 6 months postoperatively, which was significantly higher than the rate of 56% in the PEEK group (P < 0.05), and there was no statistically significant difference in the final fusion rate between the two groups (P>0.05). The ODI, the postoperative VAS score was significantly lower than that in preoperation, while the postoperative JOA score was significantly higher than that in preoperation (P < 0.05). The ODI was lower while the JOA score was higher of the autogenous bone group than that of the PEEK group 6 months postoperatively (P < 0.05). CONCLUSION: In osteoporosis patients, good interbody fusion rate and improvement of lumbar vertebral function can be obtained by using autologous facet joint bone block or PEEK cage, while the fusion rate and the improvement of lumbar function with autologous facet joint bone block are better than those with PEEK cage 6 months post-operatively. PEEK cage is superior to autologous facet joint bone block in intervertebral distraction and improvement of lumbar lordosis. Significant disc space subsidence occurred in osteoporotic patients within 3 months after lumbar interbody fusion, and the subsidence of PEEK cage was more obvious than that of autologous facet joint bone block.

Comparison of rabbit rib defect regeneration with and without graft.

Rib segment, as one of the most widely used autologous boneresources for bone repair, is commonly isolated with an empty left in the defect. Although defective rib repair is thought to be unnecessary traditionally, it's of vital importance actually to promote rib regeneration for patients with better postoperative recovery and higher life quality. Comparative investigations on rabbit rib bone regeneration with and without graft were reported in this article. A segmental defect was performed on the 8th rib of 4-month-old male New Zealand rabbits. The mineralized collagen bone graft (MC) was implanted into the defect and evaluated for up to 12 weeks. The rib bone repair was investigated by using X-ray at 4, 8 and 12 weeks and histological examinations at 12 weeks after surgery, which showed a higher bone remodeling activity in the groups with MC implantation in comparison with blank control group, especially at the early stage of remodeling.

Differences of treatment outcomes between self-ligating brackets with microimplant and headgear anchorages in adults with bimaxillary protrusion.

INTRODUCTION: Our aim was to determine differences between the outcomes of treatment using microimplant anchorage compared with headgear anchorage in adult patients with bimaxillary protrusion treated with self-ligating brackets. METHODS: Thirty-one adult orthodontic patients (13 men, 18 women; age, 25.87 ± 3.37 years) who were diagnosed with bimaxillary protrusion were selected. All patients were treated with self-ligating brackets and maximum anchorage after extraction of 4 first premolars. Group 1 received microimplant anchorage, and group 2 received headgear. Lateral cephalometric radiographs were obtained before and after treatment. Differences in the skeletal and dental parameters between and within groups were analyzed. RESULTS: No significant difference was observed in the mean treatment times between the groups (21.93 ± 3.10 vs 23.88 ± 2.68 months). There was no significant difference in skeletal measurements before or after treatment in patients who received microimplant anchorage. Patients who received headgear anchorage had an increase of the mandibular plane angle. The microimplant anchorage group had greater anterior tooth retraction and less maxillary molar mesialization than did the headgear group. CONCLUSIONS: In both the anteroposterior and vertical directions, microimplant anchorage achieved better control than did the traditional headgear appliance during the treatment of bimaxillary protrusion.

Metallic corrosion in the polluted urban atmosphere of Hong Kong.

This study aimed to explore the relationship between air pollutants, particularly acidic particles, and metallic material corrosion. An atmospheric corrosion test was carried out in spring-summer 2012 at a polluted urban site, i.e., Tung Chung in western Hong Kong. Nine types of metallic materials, namely iron, Q235 steel, 20# steel, 16Mn steel, copper, bronze, brass, aluminum, and aluminum alloy, were selected as specimens for corrosion tests. Ten sets of the nine materials were all exposed to ambient air, and then each set was collected individually after exposure to ambient air for consecutive 6, 13, 20, 27, 35, 42, 49, 56, 63, and 70 days, respectively. After the removal of the corrosion products on the surface of the exposed specimens, the corrosion rate of each material was determined. The surface structure of materials was observed using scanning electron microscopy (SEM) before and after the corrosion tests. Environmental factors including temperature, relative humidity, concentrations of gaseous pollutants, i.e., sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and particulate-phase pollutants, i.e., PM2.5 (FSP) and PM10 (RSP), were monitored. Correlation analysis between environmental factors and corrosion rate of materials indicated that iron and carbon steel were damaged by both gaseous pollutants (SO2 and NO2) and particles. Copper and copper alloys were mainly corroded by gaseous pollutants (SO2 and O3), while corrosion of aluminum and aluminum alloy was mainly attributed to NO2 and particles.

[Consistency of the subjective evaluation of malocclusion severity by the Chinese orthodontic experts].

OBJECTIVE: To assess the consistency of the subjective evaluation of malocclusion severity by the Chinese orthodontic experts. METHODS: Sixty-nine Chinese orthodontic experts subjectively evaluated the malocclusion severity for 120 cases which were selected randomly from 6 University orthodontic clinics by checking each case's pretreatment records including study cast, lateral head film, panoramic radiograph, facial photographs and patient chart. Each orthodontist was asked to independently rate the severity of every case into five grades: mild, mildly moderate, moderate, severely moderate and severe. Rating data was finally gathered to evaluate the intra-judge's reliability and the inter-judges' consistency. RESULTS: Weighted Kappa test revealed that 8.33% orthodontists showed excellent intra-judge's reliability (Kappa ≥ 0.81), 78.33% orthodontists showed good intra-judge's reliability (Kappa ≥ 0.61) and 96.67% specialists displayed general intra-judge's reliability (Kappa ≥ 0.41). And intra-class correlation coefficient demonstrated a high level of inter-judges' consistency (r=0.989, P<0.01). CONCLUSION: Good intra-judge's reliability and inter-judges' consistency can be demonstrated in the subjective evaluation of malocclusion severity by the Chinese orthodontic experts, which could the basis for establishing the objective grading system of malocclusion severity.

Cephalometric analysis of craniofacial malformations in newborn mice with cleft palate induced by retinoic acid.

OBJECTIVE: To determine changes on craniofacial growth morphometrically in newborn mice with cleft palate induced by retinoic acid. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS: Gestation day 10 or 12 pregnant female C57BL/6N mice were given a single dose of all-trans retinoic acid (atRA) by gastric intubations via oral gavage. Sixty newborn mice with cleft palate (CP), 52 without CP from the experimental group, and 30 without CP from the control group were collected, and lateral cephalograms were taken of all of the mice. MAIN OUTCOME MEASURES: Cephalometric analysis of the craniofacial skeleton was performed by means of a personal computer. RESULTS: Inhibition of craniofacial growth was found in the experimental groups but not in the control groups. In the maxillary bone and mandible, the amount of growth was significantly reduced. CONCLUSIONS: These results suggest that craniofacial growth is inhibited in newborn mice with cleft palate induced by retinoic acid.

Integrated treatment of perennial ryegrass: Structural characterization of hemicelluloses and improvement of enzymatic hydrolysis of cellulose.

An integrated treatment coupling ultrasonic and hydrothermal pretreatments with sequential alkali post-extractions was performed to isolate and characterize hemicelluloses from perennial ryegrass and improve the enzymatic hydrolysis efficiency of cellulose. The yield, chemical composition, and structure of water-soluble and alkali-soluble hemicelluloses obtained from the hydrothermal supernatant and hydrothermally pretreated ryegrass as well as the enzymatic hydrolysis efficiency of cellulose were comprehensively investigated by gel permeation chromatograph, high-performance anion exchange chromatography, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectra. Results showed that more than 90 % of the original hemicelluloses in ryegrass were released during the integrated treatment and all hemicellulosic fractions obtained were mainly composed of ʟ-arabino-(4-O-methyl-ᴅ-glucurono)-ᴅ-xylans, galactoanrabinoxylans and ß-glucans. In addition, the effective removal of amorphous hemicelluloses and lignin significantly increased the cellulose enzymatic hydrolysis rate of ryegrass from 43.8 to 91.1 %. These results provided new insights into the collaborative utilization of hemicelluloses and cellulose in ryegrass.

Fixed orthodontic appliance therapy and its impact on oral health-related quality of life in Chinese patients.

OBJECTIVE: To determine changes in oral health-related quality of life (OHRQoL) during fixed orthodontic appliance therapy in Chinese patients. MATERIALS AND METHODS: Two-hundred fifty Chinese orthodontic patients completed six distinct intervals of the 14-item Oral Health Impact Profile (OHIP-14, Chinese version): before treatment (T0); after the placement of the fixed appliance at 1 week (T1), 1 month (T2), 3 months (T3), and 6 months (T4); and posttreatment (T5). RESULTS: The overall response rate was 88.8% (222 of 250). Significant differences of overall OHIP-14 scores could be found between any two time points (P < .001), except for between T0 and T2 (P > .05) and between T3 and T4 (P > .05). Overall scores at T1 were significantly higher than the scores at the other intervals (P < .001), with a significant change in the scores on physical pain (P < .001), psychological discomfort (P < .001), and physical disability (P < .001). Scores at T5 were lowest among the six time points (P < .001). CONCLUSIONS: Fixed orthodontic appliance therapy did affect Chinese patients' OHRQoL. Patients were considerably compromised in terms of their overall OHRQoL until approximately 1 month after insertion. The severity of the compromised condition in terms of overall OHRQoL was greatest at 1 week with the reported impact on physical pain, psychological discomfort, and physical disability. Patients' OHRQoL was better after they completed the orthodontic treatment than before or during treatment.

Impact of malocclusion on oral health-related quality of life in young adults.

OBJECTIVE: To assess oral health-related quality of life (OHRQoL) in young adult patients with malocclusion and to measure the association between orthodontic treatment need and OHRQoL. MATERIALS AND METHODS: The study sample comprised 190 young adults aged 18 to 25 years who were attending orthodontic clinics at the Faculty of Dentistry. The Index of Orthodontic Treatment Need-Dental Health Component was used to measure orthodontic treatment need. Each participant was assessed for OHRQoL before and after treatment by using the Oral Health Impact Profile, Chinese version (OHIP-14). RESULTS: Patients who had little or no, borderline, and actual need for orthodontic treatment represented 21.6%, 50.5%, and 27.9% of the total sample, respectively. OHRQoL (total OHIP-14 score and score for each domain) improved after treatment (P < .05). Significant differences in summary OHIP-14 scores were apparent with respect to orthodontic treatment need. Participants with high treatment need reported a significantly greater negative impact on the overall OHRQoL score. The greatest impact was seen in the psychological discomfort domain and the psychological disability domain. CONCLUSION: Malocclusion has a significant negative impact on OHRQoL. This is greatest for the psychological discomfort and psychological disability domains. The orthodontic treatment of malocclusion improves OHRQoL of patients.

Preparation methods for monodispersed garlic oil microspheres in water using the microemulsion technique and their potential as antimicrobials.

Garlic oil is considered as a natural broad-spectrum antibiotic because of its well-known antimicrobial activity. However, the characteristics of easy volatility and poor aqueous solubility limit the application of garlic oil in industry. The purpose of the present work is to develop and evaluate an oil-free microemulsion by loading garlic oil in microemulsion system. Microemulsions were prepared with ethoxylated hydrogenated castor (Cremophor RH40) as surfactant, n-butanol (or ethanol) as cosurfactant, oleic acid-containing garlic oil as oil phase, and ultrapure water as water phase. The effects of the ratio of surfactant to cosurfactant and different oil concentration on the area of oil-in-water (O/W) microemulsion region in pseudoternary phase diagrams were investigated. The particle size and garlic oil encapsulation efficiency of the formed microemulsions with different formulations were also investigated. In addition, the antimicrobial activity in vitro against Escherichia coli and Staphylococcus aureus was assessed. The experimental results show that a stable microemulsion region can be obtained when the mass ratio of surfactant to cosurfactant is, respectively, 1:1, 2:1, and 3:1. Especially, when the mixture surfactants of RH40/n-butanol 2/1 (w/w) is used in the microemulsion formulation, the area of O/W microemulsion region is 0.089 with the particle size 13.29 to 13.85 nm and garlic oil encapsulation efficiency 99.5%. The prepared microemulsion solution exhibits remarkable antibacterial activity against S. aureus.

[Three-dimensional finite element analysis of maxillary incisor retraction with step-shaped vertical closing loop].

OBJECTIVE: To investigate the displacement and stress distribution of upper incisors in three-dimensional (3D) space controlled by step-shaped vertical closing loop. METHODS: The maxillary teeth and alveolar bone of a volunteer with normal occlusion were scanned with 3D spiral CT. Modeling and calculation were only carried out on right upper central incisor, lateral incisor and their alveolar bone in order to simplify the procedures. A 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was developed using Ansys finite element package. Finally, a 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was established based on mirror symmetry principle. The displacement of maxillary incisors and stress distribution in periodontal tissues were analyzed. RESULTS: When step-shaped vertical closing loop was simply drew back 1 mm, the maximum displacement of upper central incisor in labial and lingual direction were 5.29 × 10(-2) and 0.71 × 10(-2) mm; 10.47 × 10(-3) and 10.20 × 10(-3) mm in gingival and occlusal direction, 10.26 × 10(-3) and 1.63 × 10(-3) mm in medial and distal direction; the maximum displacement of upper lateral incisor in labial and lingual direction were 3.31 × 10(-2) and 0.41 × 10(-2) mm, 10.52 × 10(-3) and 5.10 × 10(-3) mm in gingival and occlusal direction, 6.29 × 10(-3) and 4.64 × 10(-3) mm in medial and distal direction, the displacement trend of them were moving lingually and gingivally similar to bodily movement. The stress peach of upper central incisor, periodontal ligament and alveolar bone were 31.35, 2.52 and 4.64 MPa, the stress peach of upper lateral incisor, periodontal ligament and alveolar bone were 19.59, 1.28 and 4.12 Mpa, the stress distribution of them were similar and the periodontal ligament buffered the stress imposed on the tooth.

Improved blood compatibility of Mg-1.0Zn-1.0Ca alloy by micro-arc oxidation.

Magnesium and its alloys have been used in the recent development of lightweight, biodegradeable implant materials. However, the corrosion properties of magnesium limit its usefulness. In a previous study, a micro-arc oxidation (MAO) method was used to modify a Mg-1.0 wt % Zn-1.0 wt % Ca alloy surface, with the purpose of improving the corrosion resistance of Mg alloys. However, the blood compatibility of MAO-treated Mg alloy is unknown. Results of cytotoxicity assays with bone marrow-derived mesenchymal stem cells showed that extracts of MAO-treated alloy significantly decreased cytotoxicity compared to titanium alloy extract. Results of blood compatibility tests showed that the MAO group had a decreased hemolytic ratio (2.25%) compared to the untreated Mg alloy group (24.58%) (p < 0.001). The MAO group showed significantly shorter prothrombin and thrombin times and significantly longer activated partial thromboplastin time than the untreated Mg alloy group. Arachidonic acid- and adenosine diphosphate-induced platelet aggregations were significantly decreased by the untreated Mg alloy extract, and they were less affected by extract of MAO-treated Mg alloy. In conclusion, MAO-treated Mg-1.0 wt % Zn-1.0 wt % Ca alloy exhibits favorable blood compatibility characteristics and may be useful in the development of magnesium implant materials.

[Oral health-related quality of life in patients with fixed appliances].

OBJECTIVE: To assess oral health-related quality of life in patients with fixed appliances. METHODS: Orthodontic patients were asked to complete the scale of general conditions (Chinese version, questionnaire 1) and oral health impact profile (OHIP) -14 (Chinese version, questionnaire 2). Baseline data were collected at first visit and thereafter. The subjects finished questionnaire 2 at the 1st week, 4th week, 12th week and 24th week, respectively, after the fixed appliance was bonded. Data were analyzed to evaluate the various sample groups with different personal information and clinical parameters. Results were collated and analyzed using software package SPSS version 15.0. RESULTS: The most common negative effect was physical pain [55/222 (27.8%)] and psychological discomfort [40/222 (18.0%)], mainly in the first month. The total scores at five time points were 3, 10, 7, 5 and 4, respectively. No difference was found in quality of life in patients between sixth month with fixed appliance and without appliance (P > 0.05). Age and education status affected the quality of life (P < 0.001). CONCLUSIONS: Fixed orthodontic appliance therapy affected patients' oral health-related quality of life during treatment. The quality of life in the first month of treatment was mostly compromised and was improved later.

[Treatment of maxillary protrusion in adult with self-tapping micro-screw implants].

OBJECTIVE: To investigate the position change of upper molars and incisors in order to evaluate the stability of posterior anchorage with the application of micro-screw implant. METHODS: Eight adult patients with severe maxillary protrusion were included. Upper first premolars were extracted and upper posterior anchorage was reinforced with micro-screw implant in all patients. Cephalometric and cast analyses were carried out to record the position change of molar and micro-screw. RESULTS: During treatment the micro-screw implants kept stable in sagittal and vertical plane. Neither the mesial-distal movement nor the tipping of the upper molars during the treatment was statistically significant (P > 0.05). The edge of upper incisors was retracted by 6.86 mm and the tipping was reduced by 18.03 degrees . The center of resistance was intruded by 3.28 mm on average. Significant change was observed (P < 0.01). CONCLUSIONS: Micro-screw implant could provide good anchorage control in the orthodontic treatment.

[First molar extraction in patients with crowding: cases analysis].

OBJECTIVE: To evaluate the outcome of first molar extraction in patients with crowding. METHODS: Totally 22 patients (8 males and 14 females) from Clinic of Orthodontics, SUN Yat-sen University School of Stomatology with crowding were collected. The patients were aged 11 years 3 months to 26 years 8 months (mean age 16 years 6 months). All of them treated with 1 to 4 first molar extractions. RESULTS: The average duration of orthodontic treatment was 18.5 months. Normal overjet and overbite was achieved. Good functional occlusion was established. CONCLUSIONS: Patients with severe crowding could be successfully treated with first molar extraction.

[Three-dimensional finite element analysis of distalization of lower cuspid with light-segmented archwire technique].

OBJECTIVE: To analyze the mechanics of distalizating lower cuspid with the light-segmented archwire. METHODS: An experiment, which imitated the loading of distalizating lower cuspid with the light-segmented archwire, was performed on the three-dimensional finite element method model of lower cuspid. The patterns of stress distribution of the root were analyzed. RESULTS: Under the loading of the light-segmented archwire, the lower cuspid root presented an even pressing force distribution on the distal and lingual side and an even stretching force distribution on the mesial and buccal side. CONCLUSIONS: The light-segmented archwire would lead to bodily movement of the cuspid.

[The volume change of micronized acellular dermal matrix after injection].

OBJECTIVE: To explore a new injectable material. METHODS: Micronized swine acellular dermal matrix was injected into the ear of rabbits. The augmentation was observed and measured with pathological and transmission electron microscopic technique. RESULTS: There were fibroblasts and capillaries in the injected material. The absorption rate of injected acellular dermal matrix was 26.93% in the experimental group at 48 weeks after injection. CONCLUSION: The acellular dermal matrix is an ideal injectable material for lower absorption and easy usage.

[Changes of cranio-facial hard tissue after orthodontic treatment in bimaxillary protrusive patients].

OBJECTIVE: The aim of this study is to investigate the changes of hard tissue profile in anterior-posterior and vertical direction in bimaxillary protrusion patients after orthodontic treatment. METHODS: A total of 24 bimaxillary protrusion patients (male 8, female 16), aged from 11.2 to 29.0 (average 16.9 years old), were selected to be treated with standard edgewise technique consisted of 4 first premolars extraction. Cephalometrics were taken before and after treatment. The changes of hard tissue profile were studied using the computer-aid X-ray cephalometric analysis. RESULTS: 1. The length of the maxillary and the mandible increased significantly, but the anterior-posterior relationship of the maxillary and the mandible did not change significantly. 2. The anterior and posterior facial height increased significantly, but the ratio of anterior and posterior facial height and the angle of MP-FH which reflected the inclination of the mandible plane did not change significantly. 3. The height of the upper and lower first molar increased significantly along with the increase of the anterior and posterior facial height. 4. The height of the upper incisors increased significantly, but the height of the lower incisors decreased significantly. CONCLUSION: The anchorage in anterior-posterior and vertical direction were controlled preferably, the patients did not manifest disadvantageous vertical growth trend.