Temporomandibular joint is the pivot joint system in oral and maxillofacial chewing system, bearing the intricate function such as speaking and chewing movement. During the process of derangement or functional impairment of temporomandibular joint, there are some changes in radiograph or the synovial fluid physical and chemical properties. Besides, the variation of intra-articular pressure also reflects the pathological mechanism and course of temporomandibular joint disorders. This article will review our related researches on intra-articular pressure of temporomandibular joint in the last 30 years, including the fluctuating rule, its significance of intra-articular pressure in TMJ and the effect of that on the joint physiopathology and biomechanics, to provide new ideas for clinical diagnosis and treatment of temporomandibular disorders.
Oral and maxillofacial area constitute an important part of the human appearances, the means of treatment, the size of surgical incision become the concern of patients. With the continuous improvement of minimally invasive surgical instruments and imaging technology, minimal invasive surgery has been rapidly developed in various surgical fields that including oral and maxillofacial surgery. The purpose of minimally invasive surgery is to seek the smallest surgical incision path and the minimal tissue damage to complete the diagnosis and treatment for the patients. In recent years, with broader development and application of minimal invasive surgical techniques in the field of oral and maxillofacial surgery, such as dento-alveolar surgery, maxillofacial tumor, maxillofacial trauma, the operative approach and surgical procedures of these diseases have been changed greatly. This article intends to synthesize the literatures and the author's clinical experiences, describing the application and development of minimally invasive surgery in oral and maxillofacial surgery.
Objective To analyze circular RNA (circRNA) expression profiles in oral squamous cell carcinoma (OSCC) and its clinical significance. Methods The expression of circRNA was detected with circRNA microarray assay in three samples of OSCC tumor and matched adjacent tissues. Quantitative real-time PCR (RT-qPCR) was used to verify the expression of circRNA in 45 pair OSCC tissues and normal adjacent tissues. The relationship between the expression of circRNA and the clinicopathological characteristics of OSCC was analyzed. circRNAs/miRNAs interaction were predicted using Arraystar' s home-made miRNA target prediction software. Results 155 circRNAs were differentially expressed between the OSCC tissues and matched adjacent tissues, of which 45 circRNAs were up-regulated and 110 circRNAs were down-regulated in OSCC tissues (fold changes ≥1.5 and P < 0.05). In the selected three circRNAs that were most significantly upregulated or downregulated in OSCC, the RT-qPCR results showed that hsa_circ_0001874, hsa_circ_0001971 and has_circ_0067934 were increased, while hsa_circ_0000520, hsa_circ_0023944 and hsa_circ_0000140 were decreased in OSCC tissues versus normal adjacent tissues (P < 0.001). The results were generally consistent with the microarray data. Among the circRNA expression profiles in OSCC, the up-regulation of hsa_circ_0001874 was the highest and the expression of hsa_circ_0001874 was significantly correlated with TNM stage and tumor grade. The result of Arraystar' s home-made miRNA target prediction software indicated that miR-103a-3p, miR-107, miR-593-5p, miR-661 and miR-662 may be potential target genes of hsa_circ_0001874. Conclusion The differentially expressed circRNAs in OSCC tissues and normal adjacent tissues were identified, and these dysregulated circRNAs and their potential target gents may play important roles in the development of OSCC.
Obiective To investigate the current status of remaining teeth and edentulous jaw arch of people aged 35-44, 55-64 and 65- 74 in Guangdong province. Methods An equal- sized stratified multi-stage randomly sampling design was applied to select a total of 288 Guangdong residents in urban and rural areas, and the subjects were between the age of 35-44, 55-64 and 65-74, with a gender ratio of half to half. The status of remaining teeth and edentulous jaw arch were assessed according to the Guideline for the 4th National Oral Health Survey. Results 88.89% subjects in the 35-44 year group had more than 28 teeth and 100% subjects had more than 20 teeth, with an average of 29.88 teeth remaining and no edentulous jaw. The average remaining teeth was 26.06 in the group of 55-64 year, with 87.50% subjects having more than 20 teeth, 59.03% subjects having 28 or more teeth, 4.16% subjects having single edentulous jaw arch, and 1.04% subjects having both edentulous jaw arch. 73.96% and 35.07% subjects in the group of 65-74 year had 20 above or 28 above remaining teeth, respectively, and the average teeth was 22.94. There were 8.34% subjects having single edentulous jaw arch and 1.39% subjects having both edentulous jaws. In the 35-44 and 65-74 year group, the prevalence of missing teeth in the female was significantly higher than the male (P < 0.05), while no significant difference was found between urban and rural areas (P > 0.05). More remaining teeth were noticed in current survey (2015) when compared to the data in 2005 (P < 0.05). Conclusion The 35-44 year people have few lost teeth, and over half of the elderly people have several lost teeth. Elderly people with edentulous arch are very few.
Objective To investigate different Er:YAG laser power settings on the bonding properties of IPS e.max CAD ceramics. Methods 96 IPS e.max CAD ceramics blocks (5 mm × 5 mm × 5 mm) were prepared and randomly divided into 8 groups (n = 12), the untreated blocks served as the control, while one of the experimental groups was treated with 4.5% HF for 20 seconds, six remaining test group (C、D、E、F、G、H) were treated with different Er: YAG laser power settings: 100 mJ、200 mJ、300 mJ、400 mJ、500 mJ and 600 mJ. Morphology of the ceramic surface was observed by atomic force microscopy and its shear bond strength (SBS) was tested. Results Higher shear bond strength values were found in group C-H compared to group B, the highest is group F (24.12 ± 1.91) MPa. The difference was statistically significant. The atomic force microscope observation of the surface structure showed that the control group was smooth and flat, and the HF-like etching group formed a uniform needle-like convex structure. The laser group gradually formed a regularly arranged cylindrical convex structure, in which the surface of the G and H groups was damaged. Conclusion The Er: YAG laser power settings of 400 mJ can be used as an effective pretreatment method before bonding of IPS e.max CAD ceramic.
Objective To compare the staining effect of coffee and red tea to the different denture base materials, and to investigate the cleaning efficacy of four denture cleansers. Methods All samples were separately soaked in 1％NaClO、 Efferdent、 Polident partial and Polident overnight for 12 times within 12 days after staining by the coffee and red tea. Then, the color values of the samples were measured by the spectrocolorimeter. Results The staining effect between coffee and red tea in the two materials was statistically significant (P < 0.05); the invisible denture materials are easily colored than heat-curing denture base resins (P < 0.05); there was also a statistical difference in the cleaning effect of the denture cleaning agents at each cycle stage (P < 0.05); the trend is different in different phases of color difference (ΔE) (P < 0.05). Conlusion Compared with the Polident partial, the cleaning efficacy of 1％NaClO、Efferdent and Polident overnight were better.
Objective To clinically evaluate the bleaching effect, tooth sensitivity and rebound effect (3-month follow-up) of combined bleaching technique and deep bleaching technique. Methods 30 Patients were recruited according to inclusion and exclusion criteria. Both two dental bleaching techniques, included in-office bleaching followed by at-home bleaching, and at-home bleaching followed by in-office bleaching and at-home bleaching, which were called combined bleaching technique and deep bleaching technique, respectively, were performed in the same mouth in each subject. All subjects received at-home bleaching with 6% hydrogen peroxide (HP) for 1 h/d within 7 days on one side of the dental arch (15 on the left side and the other on the right side), and followed by three 8-minute in-office bleaching treatments in succession with 35% HP on the maxillary anterior teeth, and finally with identical at-home bleaching on the maxillary anterior teeth. Tooth color was objectively evaluated using Olympus Crystaleye Spectrophotometer at the baseline appointment, and 1st, 7th, 30th and 90th day after treatment. The soft tissues and sensitivity of gingival and hard tooth tissues were evaluated using Loe and Silness Gingival Index and Visual Analog Scale (VAS) at baseline, 1st and 7th day after treatment. Results Significantly less prominent color change and tooth sensitivity were observed in teeth received combined bleaching technique, compared with those received deep bleaching technique (P < 0.05). There was no significant difference in color rebound effect between the two bleaching techniques (P > 0.05). Conclusions Both combined bleaching technique and deep bleaching technique show satisfactory effects and the same rebound effect during the same periods of follow-up. Deep bleaching technique is a more effective method of bleaching, however, with high frequency of tooth sensitivity.
Objective To investigate the clinical effects of different restoration methods on large area defect of deciduous molars. Methods A total of 150 deciduous molars were selected and randomly divided into three groups: A, B and C. Group A was repaired with glass ionomer and compound resin, B group was repaired by Hall technique, and C group was repaired with metal preformed crown. The successful rate of restoration in 6 and 12 months was compared between the three groups. Results There was no significant difference between three groups in A, B and C (P > 0.05) in 6 months; the successful rate of 12 months repair in group B and C was significantly higher than that in group A (P < 0.05). Conclusion The success rate of Hall technique and metal performed crown is higher than that of glass ionomer and composite resin on the repair of large defects of deciduous molars.
Objective To investigate the prevalence of bifid mandibular canals (BMC), and to measure their diameter and angle. Methods CBCT images of 500 patients were used for this study. The incidence and types of bifid mandibular canals were recorded according to a modified classification of Naitoh: Ⅰ, retromolar canal; Ⅱ, dental canal; Ⅲ, forward canal; Ⅳ buccolingual canal. The diameter and angle between the accessory canal and the main mandibular canal were recorded. Results Bifid mandibular canals were found in 32.2% of the 1 000 hemi- mandibles, with the incidence rate of 52.17%, 36.02%, 6.21%, 5.59% in TypeⅠ, Ⅱ, Ⅲ, Ⅳ respectively. There are 90 cases of the mandibular branch with a diameter greater than or equal to the backbone 1/2, and 100 cases that are less than 1/2 of the backbone. The angle between the mandibular branch and the trunk Ⅰ, Ⅱ and Ⅲ were 50.21° ± 22.25°、28.81° ± 11.5° and 13.50° ± 2.39° respectively. Conclusion Bifid mandibular canals were observed at a relatively high incidence using CBCT, and the most common type was the retromolar canal. It is suggested CBCT should be taken before mandibular surgery to give an accurate evaluation of bifid mandibular canals.
Odontoma is one of the most common odontogenic tumors in the jaws, and it is widely considered as tooth hamartomas. This article reports a rare compound odontoma with 39 denticles which was checked and diagnosed radically by CBCT, and relevant literatures are reviewed.
Dental implantation is a popular way to replace natural teeth. Its prognosis is affected by a number of factors including periodontitis. A large number of studies have shown the incidence of peri-implant disease and implant failure rate in periodontal compromised patients are higher than periodontal healthy patients. Peri-implant disease is closely related to the pathogens in periodontitis. What's more, the long-term success of dental implants is affected by multiple risk factors of periodontitis such as regular oral hygiene maintenance and smoking. This paper reviews the survival rate, the pathogens and the prognosis of implants in periodontal compromised patients.
Bone graft material is not only a simple scaffold frame, but also a material with the potential to induce cells grow and differentiate into osteoblasts. The material with excellent bone induction properties can accelerate the healing of bone defect, thus repair the large area of bone defect successfully. Currently, plenty of researches regarding the bone induction in bone graft material have been reported, how to maximize the material osteoinductive potential, and to take advantage of these biological materials to produce the next generation of innovative biological material, is the current concerns. In this paper, a review is made on the bone induction properties of several kinds of bone substitutes.
With the development of laser technology, the applications of laser in the pulp diseases become more and more popular, especially in the treatment of root canals、pulp capping or pulpotomy, removal of filling materials or broken files, pulp analgesia and dental pulp devitalization. Laser as a means of adjuvant therapy can effectively improve the treatment result, and get a more stable prognosis in a long term. This article made a review on the effect of laser in the treatment of pulp diseases.
Pain is the common complication in the process of orthodontic treatment, which brings a lot of trouble to patients and doctors. In recent years, many scholars have studied many methods to alleviate orthodontic pain, such as drugs, laser irradiation, using new materials and some psychological therapy. This article will summarize the relief of orthodontic pain from two aspects of relieving physical and psychological discomfort.
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