MicroRNA-203 mediates Porphyromonas gingivalis LPS-induced inflammation and differentiation of periodontal ligament cells.

AIM: In this study, we aimed to explore the effects of microRNA-203 (miR-203) on Porphyromonas gingivalis lipopolysaccharide (P.g. LPS)-stimulated periodontal ligament cells (PDLCs) and identify potential molecular targets for periodontitis treatment. METHODS: Periodontal ligament cells were stimulated by P.g. LPS, followed by quantification of miR-203 and AP-1 expression. Next, loss- and gain-of-function experiments were applied in P.g. LPS-induced PDLCs. The proliferation, apoptosis, and differentiation of PDLCs were determined, and mineralized nodule numbers were counted. Functional assays were used to identify interactions among miR-203, activator protein-1 (AP-1), and intercellular adhesion molecule-1 (ICAM-1). In addition, expression of osteogenesis-related genes and release of proinflammatory factors were analyzed. RESULTS: miR-203 was found to be downregulated while AP-1 was upregulated in PDLCs stimulated by P.g. LPS. The overexpression of miR-203 promoted P.g. LPS-stimulated PDLC proliferation and differentiation, inhibited apoptosis, and increased the number of mineralized nodules. miR-203 was verified to downregulate AP-1/ICAM-1 axis. miR-203 overexpression reduced the secretion of proinflammatory factors while increasing the expression of osteogenesis-related genes in P.g. LPS-stimulated PDLCs, which was reversed by overexpressing AP-1 and ICAM-1. CONCLUSION: These experimental data demonstrated the potential inhibitory effects of overexpressed miR-203 on periodontitis development by promoting PDLC differentiation and suppressing inflammatory responses through AP-1/ICAM-1 axis.

Distinct lipid membrane interaction and uptake of differentially charged nanoplastics in bacteria.

BACKGROUND: Nanoplastics have been recently found widely distributed in our natural environment where ubiquitously bacteria are major participants in various material cycles. Understanding how nanoplastics interact with bacterial cell membrane is critical to grasp their uptake processes as well as to analyze their associated risks in ecosystems and human microflora. However, little is known about the detailed interaction of differentially charged nanoplastics with bacteria. The present work experimentally and theoretically demonstrated that nanoplastics enter into bacteria depending on the surface charges and cell envelope structural features, and proved the shielding role of membrane lipids against nanoplastics. RESULTS: Positively charged polystyrene nanoplastics (PS-NH2, 80 nm) can efficiently translocate across cell membranes, while negatively charged PS (PS-COOH) and neutral PS show almost no or much less efficacy in translocation. Molecular dynamics simulations revealed that the PS-NH2 displayed more favourable electrostatic interactions with bacterial membranes and was subjected to internalisation through membrane penetration. The positively charged nanoplastics destroy cell envelope of Gram-positive B. subtilis by forming membrane pore, while enter into the Gram-negative E. coli with a relatively intact envelope. The accumulated positively charged nanoplastics conveyed more cell stress by inducing a higher level of reactive oxygen species (ROS). However, the subsequently released membrane lipid-coated nanoplastics were nearly nontoxic to cells, and like wise, stealthy bacteria wrapped up with artifical lipid layers became less sensitive to the positively charged nanoplastics, thereby illustrating that the membrane lipid can shield the strong interaction between the positively charged nanoplastics and cells. CONCLUSIONS: Our findings elucidated the molecular mechanism of nanoplastics' interaction and accumulation within bacteria, and implied the shielding and internalization effect of membrane lipid on toxic nanoplastics could promote bacteria for potential plastic bioremediation.

Hyperglycemia modulates M1/M2 macrophage polarization via reactive oxygen species overproduction in ligature-induced periodontitis.

BACKGROUND AND OBJECTIVE: Periodontitis in diabetic patients is characterized by enhanced inflammation and aggravated tissue damage in comparison with that in non-diabetic counterparts. The progression of periodontal damage under diabetic condition can be partly ascribed to hyperglycemia-induced disturbance between immune activation and inflammation resolution, where macrophages are capable of participating given their plasticity in response to different stimuli. Herein, we aimed to investigate the changes of macrophage polarization in periodontitis under diabetic condition and the underlying mechanism. MATERIALS AND METHODS: Type-1 diabetes was induced by the injection of streptozotocin (STZ, 60 mg/kg) in Sprague-Dawley rats. Rats in N-acetyl cysteine (NAC)-treated groups received NAC dissolved in drinking water (200 mg/kg/day). Experimental periodontitis was induced by ligating 3-0 silk around left maxillary second molars for 4 weeks. Alveolar bone destruction was tested by micro-computed tomography and tartrate-resistant acid phosphatase (TRAP) staining. M1/M2 macrophage polarization in periodontal tissue was detected by immunohistochemistry staining. RAW264.7 were cultured in normal glucose (5.5 mM) or high glucose environment (25 mM) with or without NAC (8 mmol/L). LPS (100 ng/ml) and IL-4 (20 ng/ml) were used to induce M1 macrophages and M2 macrophages, respectively. M1/M2 macrophage polarization was detected by qRT-PCR, immunofluorescent staining, and flow cytometry. Reactive oxygen species (ROS) accumulation was detected by fluorogenic probes. RANKL (100 ng/ml) were applied to induce osteoclastogenic differentiation of RAW264.7, and osteoclast formation was examined by TRAP staining. RESULTS: Rats with diabetes displayed enhanced macrophages infiltration and M1 macrophage polarization in periodontal lesions compared with vehicle-treated rats. Under LPS or IL-4 stimulation, high glucose culture of RAW264.7 elevated ROS level and increased the expression of M1 macrophage markers (iNOS, TNF-α, and IL-6) whereas decreased the expression of M2 macrophage markers (Arg-1 and CD206). Supernatants of high glucose-treated M1/M2 macrophages enhanced osteoclast formation compared to normal glucose-cultured cells. Decreasing ROS level via NAC partially reversed the effect of high glucose on M1/M2 macrophage polarization. Meanwhile, daily intake of NAC in rodent models inhibited M1 macrophage polarization, which subsequently ameliorated alveolar bone loss and decreased osteoclast numbers in periodontitis in diabetic rats. CONCLUSION: These findings demonstrated that hyperglycemia could polarize macrophage toward M1 macrophages via overproducing ROS under inflammatory condition, which might take responsibility for aggravated periodontal damage in periodontitis under diabetic condition. Inhibiting M1 macrophages and restoring M2 macrophages by ROS scavenger is hopefully a potential adjunct treatment strategy for diabetic periodontitis.

Intentional Replantation of a Second Premolar with Internal Resorption and Root Fracture: A Case Report.

AIM: This case aims to detail intentional replantation as a last resort to save an otherwise hopeless premolar with perforated internal resorption and root fracture. BACKGROUND: Internal root resorption, progressive destruction of intraradicular dentin, is a condition that sometimes renders a tooth non-restorable. In the rare cases reported where severe internal resorption leads to root fracture, extraction of the tooth seemed to be a common treatment of choice, and a few literatures had reported endodontic surgery as an alternative treatment option. To date, there had been no report of treating internal root resorption using intentional replantation. CASE DESCRIPTION: A 20-year-old male presented swelling at the buccal region of his left maxillary second premolar (#13). Clinical examination revealed a sinus tract and fractured dens evaginatus at the occlusal surface of the tooth. Radiographically, a large area of radiolucency was detected within the middle third of the root, where root fracture was present, leaving a triangular-shaped mature root apex. The condition was diagnosed as internal root resorption and root fracture. Endodontic surgery was excluded from treatment choices due to potential damage of periodontal bone. Instead, intentional replantation was performed, with the application of biomaterials including mineral trioxide aggregate (MTA) and platelet-rich fibrin (L-PRF). The tooth achieved satisfactory healing and remained asymptomatic after 2 years of follow-up. CONCLUSION: The successful outcome of the case suggests that intentional replantation could preserve a fractured tooth caused by internal root resorption. Incorporated application of biomaterials, such as MTA and L-PRF, might as well improve the chances of saving this otherwise hopeless tooth. CLINICAL SIGNIFICANCE: Through careful planning and execution, intentional replantation is a viable alternative treatment option to preserve a fractured tooth caused by internal root resorption, while leaving periodontal bone architecture almost intact. How to cite this article: Yang Y, Zhang B, Huang C, et al. Intentional Replantation of a Second Premolar with Internal Resorption and Root Fracture: A Case Report. J Contemp Dent Pract 2021;22(5):562-567.

Comparison of near-infrared imaging with cone-beam computed tomography for proximal caries detection in permanent dentition: An in vivo study.

OBJECTIVES: This study aimed to evaluate the diagnostic performance of near-infrared imaging (NIRI) and unaided visual examination (UVE) in detecting proximal caries in permanent dentition in comparison with cone-beam computed tomography (CBCT). METHODS: Patients who underwent NIRI, UVE, and CBCT imaging within 1 week were enrolled. Using CBCT as the reference test, the positive percent agreement (PPA), negative percent agreement (NPA), and overall percent agreement (OPA) of NIRI, UVE, and a combination of the two for detecting proximal caries at different depths and in different tooth locations were assessed. Additionally, the consistency of these diagnostic methods with CBCT was evaluated. RESULTS: We evaluated 6,084 proximal surfaces and identified 177 CBCT-positive sites. NIRI had a PPA, NPA, and OPA of 68.93 %, 99.09 %, and 98.21 %, respectively, with a substantial agreement with CBCT. When combined with UVE, the PPA increased by approximately 50 % compared with that of UVE alone. Regarding caries at different depths, NIRI outperformed UVE in detecting initial caries (ICDAS 1-2) over moderate-to-advanced caries (ICDAS 3-6). However, the combined use of NIRI and UVE improved the detection of moderate-to-advanced caries. In the anterior teeth region, NIRI exhibited excellent agreement with CBCT, surpassing its performance in the posterior region. CONCLUSIONS: Although NIRI cannot fully replace radiographic methods, the substantial agreement of NIRI with CBCT in detecting proximal caries highlights its potential as a complementary tool in routine caries screening, especially when combined with UVE. CLINICAL SIGNIFICANCE: This study highlights the potential of NIRI as a radiation-free method for detecting proximal caries in permanent teeth. Early detection through regular NIRI scanning can lead to timely intervention, improved patient outcomes, and reduced overall disease burden.

Cationic liposomes overcome neutralizing antibodies and enhance reovirus efficacy in ovarian cancer.

Reovirus (Reo) has shown promising potential in specifically killing tumor cells, and offering new possibilities for ovarian cancer (OC) treatment. However, neutralizing antibodies in the ascites from OC patients greatly limit the further application of Reo. In this study, we employed cationic liposomes (Lipo) to deliver Reo, significantly enhancing its ability to enter OC cells and its effectiveness in killing these cells under ascitic conditions. Pre-treatment with the MßCD inhibitor notably decreased Reo-mediated tumor cell death, indicating that Lipo primarily enables Reo's cellular uptake through caveolin-mediated endocytosis. Our results demonstrate that Lipo effectively facilitates the entry of Reo into the cytoplasm and triggers cell apoptosis. The above findings provide a new strategy to overcome the obstacle of neutralizing antibodies in the clinical application of Reo.

An inorganic mineral-based protocell with prebiotic radiation fitness.

Protocell fitness under extreme prebiotic conditions is critical in understanding the origin of life. However, little is known about protocell's survival and fitness under prebiotic radiations. Here we present a radioresistant protocell model based on assembly of two types of coacervate droplets, which are formed through interactions of inorganic polyphosphate (polyP) with divalent metal cation and cationic tripeptide, respectively. Among the coacervate droplets, only the polyP-Mn droplet is radiotolerant and provides strong protection for recruited proteins. The radiosensitive polyP-tripeptide droplet sequestered with both proteins and DNA could be encapsulated inside the polyP-Mn droplet, and form into a compartmentalized protocell. The protocell protects the inner nucleoid-like condensate through efficient reactive oxygen species' scavenging capacity of intracellular nonenzymic antioxidants including Mn-phosphate and Mn-peptide. Our results demonstrate a radioresistant protocell model with redox reaction system in response to ionizing radiation, which might enable the protocell fitness to prebiotic radiation on the primitive Earth preceding the emergence of enzyme-based fitness. This protocell might also provide applications in synthetic biology as bioreactor or drug delivery system.

Ablation of transient receptor potential vanilloid subtype 1-expressing neurons in rat trigeminal ganglia aggravated bone resorption in periodontitis with diabetes.

OBJECTIVES: We aimed to investigate the contribution of neurons expressing transient receptor potential vanilloid subtype 1 (TRPV1) to alveolar bone homeostasis in periodontitis with diabetes. DESIGN: Diabetes was induced by streptozotocin injection in Sprague-Dawley rats. Resiniferatoxin was injected into left trigeminal ganglia to ablate TRPV1-expressing neurons. 3-0 silks were tied around left maxillary second molars to induce experimental periodontitis. Alveolar bone was assessed by micro-computed tomography and tartrate-resistant acid phosphatase staining. Macrophages were detected by immunohistochemistry staining. RESULTS: TRPV1 expression in trigeminal ganglia was increased in diabetic rats compared to non-diabetic counterparts. Local ablation of TRPV1 eliminated facial heat hyperalgesia but aggravated alveolar bone damage and osteoclastogenesis in experimental periodontitis in both diabetic and non-diabetic rats. Immunohistochemistry staining presented enhanced macrophage infiltration and M1 macrophage polarization in periodontal lesions in TRPV1-ablated groups. CONCLUSIONS: These findings demonstrated that TRPV1 expression in trigeminal ganglia could be enhanced in diabetic condition, and the integrity of TRPV1-expressing neurons in trigeminal ganglia exerted a neuroprotective effect against alveolar bone resorption and inflammation in diabetic periodontitis.

Analysis of Multi-Part Phenotypic Changes in Skin to Characterize the Trajectory of Skin Aging in Chinese Women.

Purpose: As the human body's largest organ exposed to the external environment, the skin suffers from internal and external aging factors, leading to wrinkles, loss of elasticity, sagging, and rough appearance. However, little is known of the characteristics of skin aging of different body parts in Chinese women. Here, we study the signs of extrinsic skin aging in different body parts to identify the knowledge map of manifestations of aging in Chinese women. Patients and Methods: Wrinkle and texture phenotypes and collagen samples from the face, neck, hands, and arms of 326 Chinese women were collected. The correlations between phenotypes and ages and the differences in phenotypes by age were evaluated. Results: The wrinkle and texture phenotypes around the eyes and mouth and of the hands were strongly correlated with age. Ages 32 and 58 showed the largest number of differentially changed aging phenotypes. The number of aging phenotypes increased sharply between the ages of 24 and 30, suggesting that the skin was undergoing rapid aging. Eye aging was the most rapidly changing phenotype between 19 and 30 years old. Wrinkles at the corner of the eyes showed a significant difference in the older group, suggesting an early onset and long-term effects. Conclusion: This is the first study to be performed on the characteristics of skin aging among Chinese women that takes account of multiple areas of the body. It was found that 24 years old was the time point at which the skin begins to age in Chinese women. This provides important clues for aging-related research and personalized skin care.

Evidence and Impacts of Nanoplastic Accumulation on Crop Grains.

Nanoplastics are emerging pollutants of global concern. Agricultural soil is becoming a primary sink for nanoplastics generated from plastic debris. The uptake and accumulation of nanoplastics by crops contaminate the food chain and pose unexpected risks to human health. However, whether nanoplastics can enter grains and their impact on the grains of crop grown in contaminated soil is still unknown. Here, the translocation of polystyrene nanoplastics (PS-NPs) in crops, including peanut (Arachis hypogaea L.) and rice (Oryza sativa L.) is investigated. It is demonstrated PS-NPs translocation from the root and accumulation in the grains at the maturation stage. The treatment with PS-NPs (250 mg kg-1 ) increases the empty-shell numbers of rice grain by 35.45%, thereby decreasing the seed-setting rate of rice by 3.02%, and also decreases the average seed weight of peanuts by 3.45%. Moreover, PS-NPs exerted adverse effects on nutritional quality, such as decreasing the content of mineral elements, amino acids, and unsaturated fatty acids. To the knowledge, this is the first report of the presence of nanoplastics in the grains of crop plants grown in soil containing nanoplastics, and the results highlight the impact of nanoplastics on the yield and nutritional quality of crop grains.

[Differences in maxillary growth vector of skeletal class I with various vertical growth types before and after growth spurts].

OBJECTIVE: To identify the differences in maxillary growth vector with different vertical skeletal patterns of skeletal class I before and after growth spurts. METHODS: One hundred and ninety four cases with different vertical skeletal patterns of skeletal class I were selected and categorized into six groups according to their vertical skeletal patterns and cervical vertebral stages: cervical vertebral maturation stage (CVMS)1,2-horizontal pattern (n=30); CVMS1,2-average pattern (n=32); CVMS1, 2-vertical pattern (n=33); CVMS5, 6-horizontal pattern (n=34); CVMS5, 6-average pattern (n=29); and CVMS5, 6-vertical pattern (n=36). Lateral cephalograms were taken on all of the cases. The angle SN-C axis (theta) and angel PP-C axis (alpha) were measured. RESULTS: (1) The skeletal class I with a vertical growth pattern had larger angle SN-C axis than those with a horizontal or average growth pattern before growth spurts (P(average-vertical) < 0.05, P(horizontal-vertical) < 0.001). (2) The skeletal class I with a vertical growth pattern had the largest angle SN-C axis after growth spurts, followed by those with an average growth pattern. Those with a horizontal growth pattern had the smallest angle SN-C axis. The differences were statistically significant (P(horizontal-average) < 0.05, P(horizontal-vertical) < 0.001, P(average-vertical) < 0.001). (3) The skeletal class I with the same vertical growth pattern had slightly larger angle SN-C axis after growth spurts than before growth spurts, but without statistical significance. (4) The skeletal class I had relatively stable angle PP-C axis and no significant differences were found before and after growth spurts or among those with various vertical skeletal facial types. CONCLUSION: The magnitude of angle SN-C axis is closely associated with vertical growth patterns and is weakly influenced by maxillofacial growth and development.

Foot-and-mouth disease virus leader proteinase inhibits dsRNA-induced type I interferon transcription by decreasing interferon regulatory factor 3/7 in protein levels.

The leader proteinase (L(pro)) of foot-and-mouth disease virus (FMDV) has been identified as an interferon-beta (IFN-beta) antagonist that disrupts the integrity of transcription factor nuclear factor kappaB (NF-kappaB). In this study, we showed that the reduction of double stranded RNA (dsRNA)-induced IFN-alpha1/beta expression caused by L(pro) was also associated with a decrease of interferon regulatory factor 3/7 (IRF-3/7) in protein levels, two critical transcription factors for activation of IFN-alpha/beta. Furthermore, overexpression of L(pro) significantly reduced the transcription of multiple IRF-responsive genes including 2',5'-OAS, ISG54, IP-10, and RANTES. Screening L(pro) mutants indicated that the ability to process eIF-4G of L(pro) is not required for suppressing dsRNA-induced activation of the IFN-alpha1/beta promoter and decreasing IRF-3/7 expression. Taken together, our results demonstrate that, in addition to disrupting NF-kappaB, L(pro) also decreases IRF-3/7 expression to suppress dsRNA-induced type I IFN production, suggesting multiple strategies used by FMDV to counteract the immune response to viral infection.

Fabrication of gradient porous microneedle array by modified hot embossing for transdermal drug delivery.

A gradient porous microneedle array (GPMA) is developed for transdermal drug delivery. A modified hot embossing approach is proposed to fabricate the GPMA from poly (lactic-co-glycolic acid) powders within a cavity array mold under the coupling combination of gradient thermal and pressure multi-fields. The porosity of the microneedles is a gradient, and the pores are mainly distributed in the tip region. The liquid drug formulation can directly be loaded in the pores of the microneedle tips by dipping. GPMA could penetrate into the rabbit skin without breakage and the penetration force per microneedle is approximately 22 mN. The GPMA can diffuse a dry model drug, namely Rhodamine B, in vitro in the rabbit skin dermis. The GPMA can also effectively deliver an insulin solution in vivo in diabetes rats, lowering the blood glucose levels. Above all, as a dry or liquid drug carrier and a minimally invasive injector, the GPMA offers an effective alternative for transdermal drug delivery.

Effects of growth hormone and functional appliance on mandibular growth in an adolescent rat model.

OBJECTIVES: To investigate the individual and synergistic effects of growth hormone (GH) and functional appliance (FA) on mandibular growth in an adolescent rat model. MATERIALS AND METHODS: Forty adolescent (6-week-old) female Wistar rats were randomly divided into four groups (10 rats in each group). The control group received a sham treatment (intra-abdominal injection of phosphate-buffered saline), the GH group received an intra-abdominal injection of recombinant human growth hormone, the FA group was treated with a mandibular advancement device, and the GH+FA group received both the GH and FA treatments. The amount of mandibular growth in each group was measured quantitatively using cone-bean computed tomography. The growth of condylar cartilage and expression of matrix metalloproteinases-1 and -13 (MMP-1 and MMP-13) and type II and X collagen (Col II and Col X) were assessed using histological staining and immunostaining techniques. RESULTS: After 4 weeks, there was significant mandibular growth in the FA group compared with the control group ( P < .05). The GH+FA group had significantly greater mandibular length, thickness of condylar cartilage, and expression of MMP-1, MMP-13, Col II, and Col X in the cartilage than the other groups ( P < .05). The GH+FA group and GH group had significantly greater weight than the FA and control groups ( P < .05). CONCLUSIONS: The FA as well as GH+FA stimulated mandibular growth in adolescent rats.

Primary dysmenorrhea is potentially predictive for initial orthodontic pain in female patients.

OBJECTIVE: To investigate the relationship between primary dysmenorrhea (PD) and orthodontic pain in female patients, and to test the hypothesis that the intensity and duration of orthodontic pain could be roughly predicted by severity of PD. MATERIALS AND METHODS: One hundred twenty college females were enrolled and put into one of three groups-mild (Mi), moderate (Mo), or severe (S)-according to level of menstrual pain. Intensity of the orthodontic pain was measured by visual analog scale (VAS) on days 1, 2, 4, 7, 14, and 28 after archwire placement. RESULTS: As the intensity of orthodontic pain declined with time, the three groups demonstrated different changes during the initial week. Mi had the lowest VAS scores, whereas S possessed the highest scores. In contrast, Mo stayed in between. Significantly positive correlations were found between the severity of PD and the intensity of orthodontic pain at each time point within the first 2 weeks. In addition, though the majority of subjects reported disappearance of pain by the end of the second week in both Mi and Mo, a large proportion of females still perceived pain in S. CONCLUSION: Females with higher levels of menstrual pain tended to perceive orthodontic pain with higher intensity and more prolonged duration. Thus, PD could potentially serve as a reference to predict orthodontic pain in clinical settings.

Occlusal plane canting reduction accompanies mandibular counterclockwise rotation in camouflaging treatment of hyperdivergent skeletal Class II malocclusion.

OBJECTIVE: To investigate the occlusal configurations of the hyperdivergent skeletal Class II malocclusion and their alterations during the camouflaging treatment in an attempt to identify occlusal changes that might be related to mandibular counterclockwise rotation. MATERIALS AND METHODS: Cephalograms of 126 subjects with hyperdivergent skeletal Class II malocclusion and 126 subjects with a clinically normal skeletal pattern were chosen. Several measurements were calculated and compared between the groups. To examine the effects of treatment, two groups were established according to mandibular rotation: counterclockwise rotation (CCR) and the opposite clockwise rotation (CR). After 40 subjects were excluded, the other 86 Class II subjects were assigned to CCR (n = 22) and CR (n = 64). Their pretreatment (T1), posttreatment (T2), and postretention (T3) cephalograms were obtained. Measurement changes (T3-T1) were analyzed in each group and compared between groups. RESULTS: Compared with the normal skeletal pattern, the cant of the occlusal plane (OP) of the study subjects was significantly steeper and the vertical heights of the incisors were significantly larger for the malocclusion. Compared with the changes in CR, there was a prominent reduction of the OP canting with remarkable intrusion of the maxillary incisor in CCR. CONCLUSION: Increased OP canting with overerupted incisors is evident in the hyperdivergent skeletal Class II malocclusion. During the camouflaging treatment, reduction of OP canting could occur. It was accompanied by mandibular counterclockwise rotation and intrusion of the maxillary incisor.

Preparation and properties of g-TTCP/PBS nanocomposites and its in vitro biocompatibility assay.

In an effort to decrease the aggregation of tetracalcium phosphate (TTCP, Ca4(PO4)2O) in composites and develop better bone substitute materials, a series of poly(l-lactic acid) (PLLA)-grafted TTCP (g-TTCP) particles were prepared by a ring-opening polymerization with l-lactide (the monomer for synthesizing PLLA) in the presence of catalyst stannous octoate [Sn(Oct)2]. The g-TTCP/poly(1,4-butylene succinate) (PBS) composites with the different g-TTCP contents were prepared via melting processing. The bonding between the PLLA and the TTCP particles was analyzed by FTIR, TG, (1)H NMR and XPS. The results confirmed that the PLLA was grafted on the surface of the TTCP particles. Time-dependent phase monitoring indicated that the g-TTCP had enhanced dispersion in the PBS solution. Water contact angle measurement and cell culture were also used to investigate the properties of the g-TTCP/PBS composites. The g-TTCP in composites provided more favorable environments for rat osteoblast to attach and grow on the surface of the g-TTCP/PBS composites. Cell proliferated well in the extracted solution of the g-TTCP/PBS composites with different g-TTCP content, and there was no necrotic or suspended cells appeared.

[Cephalometric analysis of the relationship between occlusal plane and sagittal position of the mandible].

OBJECTIVE: To investigate the relationship between occlusal plane and sagittal position of the mandible by examining dental and skeletal morphologies of average angle patients for better understanding of etiologies and definitive clinical guidelines of mandibular malpositions. METHODS: The lateral cephalograms of 114 female average angle patients with neutral maxillary positions were selected and divided into three groups according to sagittal mandibular positions (ANB angle). Twenty-five skeletal and dental measurements were compared. The correlations between skeletal and dental measurements were analyzed by rectilinear correlation. RESULTS: Cant of posterior occlusal plane (OP-P) and height of the upper second molar were significantly related to sagittal position of the mandible (P < 0.05). Height of the upper second molar was relatively inadequate and OP-P was sloped when the mandible was positioned posteriorly; conversely, height of the upper second molar was excessive and OP-P tended to be flat when the mandible was positioned anteriorly. Tooth axial inclinations were affected by sagittal position of the mandible. Maxillary teeth proclined distally and mandibular ones mesially for patients with retrognathia. On the other hand, maxillary teeth proclined mesially while mandibular ones distally for patients with prognathia. CONCLUSION: There was a definite relationship between cant of posterior occlusal plane and sagittal position of the mandible in average angle patients, consistent with the dental morphologies of different skeletal configurations. In treating malocclusions of sagittal discrepancy of mandible, the height of posterior teeth and cant of OP-P might be a primary concern.

[The measurement of utility value for skeletal malocclusion].

OBJECTIVE: To measure the utility value of different skeletal malocclusion for patients receiving orthodontic treatment. METHODS: Utility value of different skeletal malocclusion for patients was measured by rating scale and time trade-off. RESULTS: The youth group had higher utility values than adult group for skeletal malocclusion Class II (protruding facial type) with median mandibular angle. The utility value of skeletal malocclusion Class III (concave facial type) with low mandibular angle was the lowest, and the utility value of skeletal malocclusion Class II (protruding facial type) with median mandibular angle was the highest. There was no difference in the utility values by rating scale and by time trade-off. CONCLUSION: For some skeletal malocclusion, the youth had different utility values with the adult.