The mandible is the most important bony support in the lower 1/3 skeleton of the face which is critical for both esthetics and function. Mandibular defects, resulting from tumor resection, can cause severe functional and cosmetic deformities. Nowadays, vascularized bony tissue transfer such as free fibula flap has been widely used for mandibular reconstruction. However, traditional mandibular reconstruction based on clinical experience may hawe some problems in accuracy and efficiency because of lacking individualized design. In recent years, digital surgical techniques such as computer-aided design, rapid prototyping and surgical navigation have been used for mandibular reconstruction surgery. Accurate design for tumor resection as well as individualized design for mandibular reconstruction can be performed with computer preoperatively which help to turn the virtual plan into reality by using surgical guide or navigation. Many studies suggested that digital surgical techniques could significantly improve the clinical outcome of mandibular reconstruction. In this article, we summarized the application of digital surgical techniques for mandibular reconstruction based on our own experience and literatures review.
Objective To compare the osteogenic differentiation abilities of human bone marrow mesenchymal stem cells (hBMSCs) from different sources, and to provide basis for choosing a new source of seed cells in bone tissue engineering. Methods Jaw bone-marrow-derived mesenchymal stem cells (JMMSCs) were isolated from orthognathic surgical sites and cultured by limited dilution for single cell clone. Long bone-marrow-derived mesenchymal stem cells (BMMSCs) were obtained from bone marrow of volunteers and isolated by density gradient centrifugation method. Flow cytometry was used to detect the surface markers of both cells. Osteogenic ability was assessed by PCR and Western Blot after osteogenic differentiation for the following molecules: Runx2, COL-1 and OCN. Alizarin red staining was used for determining the ability of cell mineralization after osteogenic differentiation. Results The expressions of cell surface markers CD90 and CD105 were positive in both type of cells, while CD34, CD14 and CD45 were all negative. After 21 days of osteogenic induction, JMMSCs formed significantly more mineralized nodules than BMMSCs. After 7, 14, 21 days of osteogenic induction, JMMSCs expressed more osteogenic-related molecules than BMMSCs. Conclusion The osteogenic differentiation capacity and mineralization ability of JMMSCs are significantly higher than BMMSCs. Jaw bone might be a more suitable source of seed cells in bone tissue engineering compared with long bone.
Objective The purpose of this study was to compare the effects of different concentrations of green tea on salivary flow rate and pH value. Methods 20 healthy college students aged from 18 to 25 were included in this study, at State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University. Salivary flow rate and pH value were measured between 21: 00 and 22: 00 after drinking water, low, medium, and high concentration of green tea. Results Female salivary flow rates in low and medium concentration group were significant higher than that in high concentration group and water group (F=5.20, P < 0.01). There was no significant difference in male salivary flow rates among 4 groups (F=1.810, P=0.143). Salivary pH value in 3 green tea groups were lower than that in water group (F=3.50, P=0.02), with no significant difference among them. Conclusion Low and medium concentration green tea prevent decrease of salivary flow rate in healthy women but not in males. Salivary pH lowers after drinking different concentrations of green tea.
Objective To observe the efficacy of BISCOVER LV tooth liquid polish sealant and Tooth Mousse Dental protective agent on mineralization around the orthodontic brackets during orthodontic treatment. Methods 60 teeth with bonded orthodontic brackets were randomly divided into three groups, experimental group, positive control group and negative control group, they were applied separately with tooth liquid polish sealant, Tooth Mousse and distilled water. 3 groups were dipped into an artificial caries solution and an artificial saliva solution, cycling between them.90 days later,the changes of enamel surface around the brackets of all samples were detected by microhardness tester and scanning electron microscope. Results One -way ANOVA was used for statistical analyses, there was significant difference of the microhardness of acid etched enamel surface among the three groups (P < 0.05). Through the LSD-t test, there was no significant difference of the microhardness of acid etched enamel surface between experimental group and positive control group (P > 0.05), and there were significant differences of the microhardness of acid etched enamel surface in another two comparisons within the three groups (P < 0.05). A large number of deposits were found through scanning electron microscope on the dental enamel surface of the experimental group, which could make a better remineralization.Conclusion Both BISCOVER LV tooth liquid polish sealant and Tooth Mousse Dental protective agent can effectively prevent tooth enamel from demineralization around the bracket during orthodontic treatment, doctors can choose them in accordance with the compliance of the patient.
Objective To compare the stress distribution of residual posterior root restored with a new titanium alloy post of different diameter and taper, and discuss the rational design of posterior tooth post by the three-dimensional finite element method. Methods Mandibular second premolar image data was obtained by CBCT, and the mandibular second premolar post models with different diameter and taper were established with the help of Mimics data conversion, Geomagic Studio image processing technology and Creo/Parametric software. Then Abaqus was used to simulate the load condition of prosthesis and analyze the Von Mises stress of the cervical and apical regions. Results With the same diameter, the influence of the different post tapers on the peak stress of the root cervical area was irregular. When the taper was the same, the peak stress of the root apex area decreased firstly and then increased as the diameter increased. When the diameter was 1 mm, the peak stress of the root cervical and apex area was the lowest. Conclusion The effect of diameter on the stress distribution of dentin is more important than that of taper. To select the reasonable diameter and taper of the post is helpful to reduce the peak stress of the root cervical and apex area.
Objective The purpose of this study is to determine the accuracy of implant placement in the edentulous jaw using computer planning and fully-guided mucosa-supported surgical template by Simplant software. Methods 63 implants were placed in 9 patients (11 fully edentulous jaws), 26 implants were placed in upper edentulous jaw and 37 implants in lower edentulous jaw. Preoperatively, first, a cone beam CT was required for patients with radiographic template and radiographic template respectively. Therefore, the data of CBCT was inputted in Simplant software by DICOM format, followed by virtual implant planning. Hereafter, a mucosa-supported surgical template was designed by dentist and made by Masterilise company to allow implant placement using the template as a guide. To investigate the accuracy of implant placement, a postoperative CBCT scan was obtained and matched to the preoperative scan. The accuracy of implant placement was validated three-dimensionally including divations of implant shoulder, apical point, axial angulation and depth. Results The survival rate of 63 implamts for a 6 month to 10 year observation period was 100%. The mean divation of implant shoulder was 0.73 ± 0.53 mm, implant apical point was 1.15 ± 0.62 mm, implant depth was 0.95 ± 0.64 mm and implant axial angulationwas 4.10 ° ± 3.23°. Conclusion Divation between virtual and actual implant was existed and it should be considered preoperatively when virtual implant was planned to avoid injuring anatomic structure and keeping surgery safely. Correct manipulation during implant operation are helpful to decrease the divation of implant placement.
Objective To evaluate the clinical outcomes of custom all-ceramic crown fabricated in zirconia based on CT data in maxillary anterior implant tooth. Methods 15 patients with single anterior tooth missing were applied to this treatment. Crown remodeling according to the opposite tooth, fabrication of the all-ceramic crown was finished based on the data capture via CT scan. The observation period extended 2-7 years on average. Results The survival and success rates were 100%. Soft tissue was stabile in follow up photos. All of the patients were satisfied with the restorations. Conclusion The custom all-ceramic crown based on CT data showed good interface friendship with both of the hard and soft tissues and the aesthetics result is predictable.
Objective To explore the effect of anterior alveolar bone reconstruction achieved through autogenous block bone from the wisdom teeth extraction zone in onlay grafting technique. Methods The 20 patients with bone defect of anterior teeth area were selected. They all had impacted teeth with no infection factors of pericoronitis to be removed. They were treated with autogenous block bone grafts from wisdom teeth extraction zone in onlay grafting technique respectively. The changes of thickness and the height of the bone measured from CBCT before and after 6 months of the surgery were carefully compared. Questionnaire from the patients opinion of acceptance was also be collected. Results Acceptance questionnaire showed an average score of 55 points (60 full score). Among them, 75% of paitients showed totally supportion and 25% showed basically supportion. The thickness was 6.73 ± 0.28 mm after the surgery compared with 2.26 ± 0.57 mm before the surgery which illustrated a significant difference (F = 6.32, P<0.001). The height didn't change obviously before 14.32 ± 0.31 mm and after 14.56 ± 0.35 mm the surgery. The technique of using autogenous block bone from the wisdom teeth extraction zone improved the compliance of patients with surgery. It can provide good osteogenesis effect and solve other oral diseases at the same time. Conclusion The Onlay grafting technique which using autogenous block bone from the wisdom teeth extraction zone was a simple and effective techniques for anterior alveolar bone augmentation.
Objective To assess the result of treatment in ClassⅡmalocclusion subdivision with unilateral Forsus appliance. Methods 23 patients with ClassⅡmalocclusion subdivision were selected, who were treated with Straight wire fixed appliance in combination with unilateral Forsus appliances while another 27 patients were untreated as control group. Lateral cephalographs were taken before and after the comprehensive treatment, and the indicators of dental, skeletal, and soft tissue profile were measured. Results The Forsus appliance can correct ClassⅡmalocclusion subdivision through distalizing the upper teeth and moving the lower teeth mesially. Midline can be corrected at the same time. There was a statistically significant difference in the amount of tooth movement (P < 0.05). Conclusion Forsus appliance is an effective device for treating ClassⅡmalocclusion subdivision, which can induce significant dental and soft tissue changes.
Objective To investigate the clinical efficacy of painless oral anesthesia combined with piezosurgery compared with ordinary cassette syringe combined with high speed turbine handpiece in the Fenestration operation of orthodontic traction of impacted maxillary anterior teeth. Methods A total of 128 cases of impacted maxillary anterior teeth were treated with Fenestration operation and orthodontic traction, and the patients were randomly divided into two groups. Group A (64 patients) received painless oral anesthesia combined with piezosurgery. Group B (64 patients) received ordinary cassette syringe combined with high speed turbine handpiece. The cooperation of fenestration and the swelling and pain after operation were compared between the 2 groups. Results The proportion of 0 and Ⅰ in the anesthesia group was 45.3% and 31.3% respectively, and the conventional group 0 and I accounted for 32.8% and 20.3% respectively. The difference between the two groups was statistically significant (Z=-2.676, P < 0.05). The pateints' cooperative degree in group A was better than that in group B (P < 0.05). The ratio of pain and swelling in the anesthesia instrument combined with Piezosurgery group was 81.2%, the conventional group had a grade I ratio of 59.4%, and the anesthesia instrument combined with Piezosurgery group was lighter than the conventional group, The difference was statistically significant (Z=-2.777, P < 0.05); anesthesia combined with Piezosurgery group after surgery accounted for 81.2% of the swelling, the conventional group of pain accounted for 71.9%, There was significant difference between the two groups (Z=-2.097, P < 0.05). Symptoms and signs as swelling and pain degree in group A were relatively minor than those in group B (P < 0.05). Conclusion It is worthy clinical promotion to use Painless oral anesthesia combined with piezosurgery in the fenestration and orthodontic traction of impacted maxillary anterior teeth, for its better cooperation and minor post-surgery reaction.
Objective To investigate the clinical use of glass ceramic onlay in the restoration of the non-vital posterior teeth with computer aided design and computer-aided manufacturing technique (CAD/CAM). Methods 70 patients with 75 teeth of residual crown were selected and restored with CAD/CAM glass-ceramic onlay after completely root canal therapy. Marginal adaptation, anatomic form, adjacent relation, contour appearance, color match were checked in 12-month follow-up. Results Marginal adaptation, anatomic form, adjacent relation, contour appearance, color match of 73 teeth were satisfactory and 2 cases was excluded because of lost to follow-up. There were no significant differences in the number of cases which met clinical criterion A or B between immediate restoration and 12-month follow-up (P > 0.05), and more than 95% of cases met clinical criterion A. Conclusion The CAD/CAM glass-ceramic onlay in the restoration of non-vital posterior teeth can provide better effect of retention and esthetics in a short term observation of 12 months.
Objective To observe the clinical effect of traditional Chinese medicine on recurrent oral ulcer. Methods 68 patients with recurrent oral ulcer were treated in our hospital, 68 outpatients were randomly divided into two groups: treatment group and control group. The control group received outpatient symptomatic treatment and uninterrupted given cydiodin, vitamin C and compound vitamin B tablets for oral treatment; treatment group were given outpatient treatment and traditional Chinese medicine ointment conditioning based on syndrome differentiation. To observe and compare clinical efficacy of the treatment group. Results The total effective rate of the treatment group was 86.11%, which was significantly better than that of the control group 28.13%, the difference was statistically significant (P<0.01). Conclusion Traditional Chinese medicine ointment in the treatment of recurrent oral ulcer can significantly reduce recurrence rate, improve the immune function of the body, clinical efficacy, the quality of life of patients.
Among the variety of post and core materials, fiber post is getting more and more popular because of its excellent physical and mechanical characters, superior aesthetics properties. However, it also has some limitations. In the restoration of damaged teeth, there should be more dentin ferrule, and the different designs of ferrule affect the retention, stability and root fracture resistance of teeth restored with fiber posts. The purpose of this article is to give a literature review of the effect of ferrule on teeth restored with fiber posts.
This work is licensed under Creative Commons Attribution 4.0 License.
