Restoration of a dental defect in a patient with ectodermal dysplasia: a case report and literature review / 口腔疾病防治

Objective@#To explore the treatment options for congenitally missing teeth in patients with ectodermal dysplasia and provide a clinical reference.@*Methods@#A patient with ectodermal dysplasia with a concave midface, anterior protrusion of the chin, and underdevelopment of the lower third of the face presented with congenital loss of multiple maxillary teeth, malocclusion of the remaining teeth, congenital loss of mandibular dentition, small dental arches, and upper and lower alveolar bone hypoplasia. The patient was treated by means of a removable partial maxillary prosthesis, implants in the anterior region of the lower mandible designed with the assistance of digital guides, and bar-clamped implant-overlay prostheses. A literature review of the protocol for the treatment of this condition was also conducted.@*Results@#In addition to good retention and stability after denture wear, an excellent occlusal relationship, improvement of the patient's facial appearance, including upper and lower lip fullness, more equal balancing of the lower and middle 1/3 of the face, and improved masticatory function were achieved. The results of the literature review showed that patients with ectodermal dysplasia who are congenitally edentulous usually have a complex intraoral situation that makes restoration difficult, and common restorative modalities for these patients include fixed bridges, removable partial dentures, complete dentures, overdentures, and implant prostheses, which need to be selected according to the actual intraoral situation of each patient. Currently, there is no consensus on the treatment of congenitally missing teeth in patients with ectodermal dysplasia, and some scholars have suggested that fixed restorations be recommended for patients with fewer missing teeth, while the option of removable or implant-covered denture restorations should be given to patients with more missing teeth, with removeable prostheses for underage patients that are replaced with permanent fixed prostheses when the jaws have stabilized.@*Conclusion@#In patients with ectodermal dysplasia with congenital tooth loss, all factors should be taken into account, and an individualized restorative plan should be developed.

Simultaneous implantation and tooth preparation technology guided by 3D-printed guide / 华西口腔医学杂志

Using digital technologies in concurrently performing missing tooth implantation and preparation of remaining teeth is a solution to reduce the number of visits and improve efficiency. This paper proposes a digital process for simultaneously implanting and preparing teeth. It integrates implant surgical guide and 3D-printed tooth preparation guide into a single guide and completes guided implant placement and precise tooth preparation. Based on "repair-oriented" virtual implant planning, the implant surgical guide can improve the efficiency and predictability of implant placement, and its linear accuracy is about 1 mm. The tooth preparation guide precisely guides tooth preparation and restoration space visualization, ensuring the quality of the tooth preparation. The two guides have different design accuracy requirements, and thus their combination improves the overall guiding accuracy requirements. The concurrent application of the two guides minimizes the clinical operation time, number of visits, and economic burden of patients.

Effect of daidzein on OPG and RANKL expression in human osteoblast-like MG-63 cells / 中国药理学通报

Aim To study the regulatory effect of daidzein on osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) expression in MG-63 cells and its mechanism. Methods RT-PCR, Western blot and siRNA were used to study the regulatory effect of daidzein on OPG and RANKL expression in human osteoblast-like MG-63 cells. Results Daidzein could promote the expression of OPG mRNA and protein in MG-63 cells and inhibit the expression of RANKL mRNA and protein, which could be blocked by ICI 182780. It was confirmed that ERa and ER0 mediated not only the promoting effect of daidzein on OPG expression of MG-63 cells but also the inhibition of RANKL. Conclusions Daidzein promotes OPG gene expression in MG-63 cells and inhibits the expression of RANK gene expression through ERa and ERβ pathways.

Differences in implant osseointegration in the jaw and femur in animal experiments / 口腔疾病防治

@#The jaw and femur are commonly used sites in basic research for modeling bone defects or inserting implants. An increasing number of studies have identified that the jaw and femur indeed show great differences in embryonic development and growth, histomorphology and bone metabolism. A literature review showed that, compared with the femur, the main osteogenic pathway of the jaw may have better osteogenic ability, and its stem cells have better proliferation and osteogenic differentiation ability. However, the jaw structure is less regular, the osteogenic differentiation ability of its osteoblasts is mineralization slightly weak, and the immune cells of the jaw are more sensitive to cytokines. These may be the reasons why the osseointegration of the jaw implant is different from that of the femur in animal experiments, but its specific mechanism has not been clarified.

Prevention of hematoma on the floor of the mouth during dental implant surgery in the anterior mandible / 口腔疾病防治

Objective@# To explore the cause and preventive measures of floor-of-mouth hematoma after dental implant placement. @*Methods@#The prevention of hematoma of the floor of the mouth in a case of lower anterior teeth implant placement was analyzed, and the literature was reviewed.@*Results@# Four mandibular vascular canals were found on the lingual side of the anterior mandible before dental surgery in the reported case. Two of them were quite thick (1.4 mm and 1.0 mm, respectively) and were located adjacent to the crest of the alveolar bone and superior to the mental spine. These two thick endosseous branches from the sublingual artery were dissected and ligated , and there was no obvious hematoma in the patients immediately after the operation and at the postoperative 3 d review. The results of the literature review show that the incidence of endosseous branches from the lingual vascular canal of the mandible is 90%-100%. The distribution of the vessels on the lingual side of the mandible is highly variable and adjacent to the lingual cortical plate. Accidental injury of the lingual cortical plate during implant surgery would probably lead to bleeding or hematoma on the floor of the mouth. @*Conclusion @#Mastering the anatomy of blood vessels on the floor of the mouth, elaboratively examining preoperative three-dimensional radiographic imaging, and cautiously exploring the lower jaw bone morphology after flap elevation are preventive measures to avoid damage to the arterial supply on the lingual side of the anterior lower jaw and to prevent complications of hematoma in the floor of the mouth.

Precise implant insertion technology for measuring dental implant placement / 华西口腔医学杂志

Identifying the ideal implantation site is important for the long-term stability and effectiveness of follow-up restorations. Implant surgical guide and navigation are used to determine the implantation site in clinic and improve the precision of implantation. However, due to difficulties in digital methods, such as multiple procedures, high cost, and actual accuracy of more than 1 mm, many physicians still prefer to operate with free hand. In preoperative, intraoperative, and postoperative procedures, time-saving and practical methods for implant site evaluation are lacking. In many cases, oral physicians found that the position deviates only by cone beam CT, which was costly to modify the position. In this article, we presented a precise implantation insertion technology that is guided by a measurable technique throughout the implantation application for all implant systems. This method was guided by a dynamic control measuring ruler, which functions together with the measuring and intraoperative locating rulers. The 3D space of the operative area was measured by a measuring ruler prior to operation, and the implant plan and quantitative guidance design were conducted according to the measured and cone beam CT data. The whole implantation process was guided by the dynamic control measuring ruler, and measuring verification results were also considered. This method can realize the quantification of the entire preoperative space analysis, intraoperative precise implantation guidance, and postoperative site measurement and evaluation. This practical technique also helps to adjust the position, improve the implantation accuracy and is suitable in generalizing dental implantation.

Application of digital implant guide plate in oral implant restoration / 口腔疾病防治

@#Digital implant guides have enabled "repair-oriented" implant restoration to become a reality by allowing an implant to be designed for an ideal site, maximizing the use of existing alveolar bone, and increasing the predictability of the restorative effect. This paper reviews the classification of digital guides and the related factors affecting the accuracy of digital guides to provide a reference for clinical doctors in practical applications. Digital guides can be divided into the categories of mucosal support, bone support, dental support and mixed support according to the retention mode. The manufacture and use of digital implant guides involve a series of processes, such as data acquisition, design and manufacture of the implant guide, and guided surgery. The accuracy of digital implant guides depends on all accumulated and interactive errors involved in the process from data acquisition to surgery. According to the process of guide plate fabrication and implant placement, errors in all aspects can be reduced to improve the accuracy of guide plate application.

Estudo de comparação por extensometria entre dois modelos de implante: extraoral e intraoral (estudo piloto) / Comparison study for extensometry between two implant models: extra-oral and intraoral (pilot study)

Objetivo: avaliar, por meio de extensometria, a infl uência da flange do implante de titânio na deformação superficial do osso. Material e métodos: um bloco de poliuretano simulando um osso tipo I mais corticalizado e menos medular (40 PCF) recebeu um implante de hexágono externo intraoral, sem flange 3,75 mm x 8,5 mm (G1) e um implante de hexágono externo extraoral, com flange 3,75 mm x 8 mm (G2). Em seguida, foram instalados componentes standard com 2 mm de altura de cinta metálica e cilindros metálicos para restauração provisória. Dois extensômetros lineares foram colados na superfície do bloco (mesial e distal de cada implante), e uma carga axial de 100 Ncm em uma máquina de ensaio universal foi aplicada, com cinco medições de microdeformação (µÎµ) para cada implante. Os dados foram submetidos ao teste Shapiro-Wilk para verifi car a homogenidade dos dados e em seguida ao teste t Student. Resultados: as médias e desvios-padrão obtidos foram: G1: 148,2 ± 5,84 e G2: 92,4 ± 11,24 µÆ, com diferença estatística significativa entre os grupos. Conclusão: os implantes extraorais tiveram melhor comportamento mecânico para as cargas axiais do que os implantes intraorais, sendo que a flange melhorou a distribuição da carga na superfície do bloco de poliuretano.

Objectives: to evaluate, by means of extensometry, the influence of the titanium implant flange on the superficial deformation of the bone. Material and methods: a polyurethane block simulating a more corticalized and less spinal type I bone (40 PCF) received an external intraoral hexagon implant with a 3.75 mm x 8.5 mm fl ange (G1) and an extraoral external hexagon implant, with flange 3.75 mm x 8 mm (G2). Subsequently, standard components with 2 mm high of metal strap and metal cylinders were installed for temporary restoration. Two linear strain gauges were glued to the surface of the block (mesial and distal of each implant), and an axial load of 100N in a universal test machine was applied with five microdemorphometric measurements (µÎµ) for each implant. The data were submitted to the Shapiro-Wilks test to verify the homogeneity of the data and then to the t-student test. Results: the means and standard deviations obtained were: G1: 148.2 ± 5.84 and G2: 92.4 ± 11.24 µÎµ, with signifi cant statistical difference between the groups. Conclusion: extraoral implants had better mechanical behavior for axial loads than intraoral implants, and the flange improved the load distribution on the surface of the polyurethane block.

Effect of Collagen Thread in Tension-Free Suture of Oral Implant Surgical Incision and Effect on Wound Healing Time / 昆明医科大学学报

Objective To investigate the effect of collagen line in the tension－free suture of the incision of oral implant and the effect on the healing time of the wound. Methods 100 patients were selected from January 2016 to January 2017 for repair of dental implant in Zhong Hua Dental clinic of Jinghong city, and they were randomly divided into control group and study group,with 50 cases in each group. The control group was treated with non absorbable sutures of silk suture wounds, while the study group using collagen suture wounds, then we compared two groups of patients with wound healing grade, suture line absorption, wound healing time and formation rate. Results The research group of grade A healing rate was 96%, significantly higher than 80% in the control group (P＜0.05), and the adverse reactions of the study group was 6%, lower than 20% in the control group (P＜0.05);the complete absorption rate and smooth incision rates in the study group for suture in different times were 84%, 96% 100%, and 86%, which were significantly higher than the control group's 62%, 78%, 80% and 68% (P＜ 0.05) . The wound's healing time and postoperative VAS score of 3 d, 5 d and 7 d were significantly lower than the control group (P＜0.05) . Conclusion Collagen line in oral implant surgery incision tension－free suture of wound healing and postoperative recovery is significantly better than that of silk and non absorbable sutures, and collagen can be degradated orally,which effectively improves the wound healing of patients with grades and wound flat rate, and effectively accelerates wound healing, with the value of application.

Aesthetic evaluation criteria and influencing factors of dental implant / 口腔疾病防治

@#With the development of implant technology and materials, the aesthetic of implant prosthesis has been paid more and more attention. Implant prosthesis should be coordinated with patients’ characteristics, the existing aesthetic indices have no unified standard. Based on current research and clinical experiences, this review narrated the esthetic indices of implant crowns and peri-implant soft tissue and influencing factors of dental implant in the aesthetic area.

Titanium implants:Strategies on surface modification and effect on osseointegration / 中国组织工程研究

BACKGROUND:Titanium has been widely used in dental implantation because of its good biocompatibility, mechanical properties and its similar elastic modulus to the bone. OBJECTIVE:To summarize three strategies for surface modification of titanium implants:physical modification, chemical modification and biochemical modification. METHODS:PubMed and CNKI databases were searched for articles published from January 2007 to February 2013, and the key words were“titanium, implant, surface modification, osseointegration”in English and Chinese, respectively. Articles which are closely related to titanium implant surface modification and osseointegration were included, and repetitive articles were removed. RESULTS AND CONCLUSION:After preliminary search, 199 articles were found. According to the inclusion criteria and exclusion criteria, 76 articles were further analyzed. Titanium implant is a bioinert material, and thus the researchers focus on surface modification to activate the titanium implant so as to possess biological function and achieve early osseointegration. Implant surface modification strategies include three perspectives:physical modification, chemical modification and biochemical modification which can shorten the period of implant therapy and achieve early osseointegration and higher binding strength. The future research trend is to combine three strategies and to further explore the molecular basis of mechanism at the interface between implant and organism cel and the tissue in order to use better surface modification technology to fulfil the early and more stable osseointegration between the implant and bone tissue.

Craniofacial morphometry for craniofacial implant / Morfometría craneofacial para implante craneofacial

Craniofacial implants are being increasingly used to treat patients with sequelae of oncological resections, trauma, and congenital deficiencies, among other issues. The aim of this investigation was to establish the minimum and maximum bone dimensions present in the most used places for the insertion of craniofacial implants. A descriptive study was designed analyzing 40 human skulls using cone-beam computed tomography; in the volumetric reconstruction the points most often used in clinical investigations for the insertion of implants were selected, representing the orbital, perinasal, zygomatic bone and periauricular regions, measuring the distance between the cortical bones on the sagittal, axial and coronal planes; comparisons between gender and with other investigations with a similar aim were also made. In the supraorbital area, values of 7.92+/-1.82 mm were found and in the lateral area values of 7.54+/-0.98 mm, allowing the placement of implants 5 or 6 mm in length. In the area of the zygomatic bone, dimensions of 10.4+/-2.35 mm were obtained, allowing the placement of implants 8 mm in length. In the periauricular area values were obtained of 2.93+/-0.55 mm in the superior region and 3.1+/-0.7 mm in the inferior region, whereas in the perinasal area implants 4 mm in length can be placed. We concluded that the craniomaxillofacial bone structure presents acceptable widths for the installation of implants; the periauricular region presents lower dimensions, with the possibility of intracranial communication in areas above the external auditory meatus...

Los implantes craneofaciales están siendo cada vez más utilizado para tratar a pacientes con secuelas de resecciones oncológicas, traumatismos, y deficiencias congénitas, entre otras. El objetivo de esta investigación fue establecer las dimensiones óseas mínimas y máximas presentes en los lugares más utilizados para la inserción de implantes craneofaciales. Se diseño un estudio descriptivo que analizó 40 cráneos humanos utilizando cono Tomografía computarizada Cone-Beam; en la reconstrucción volumétrica fueron seleccionados los puntos más utilizados en las investigaciones clínicas para la inserción de implantes, que representan la orbital, hueso perinasal, hueso cigomático y regiones periauriculares. La medición de la distancia entre los huesos corticales en los planos sagital, axial y coronal, y las comparaciones entre el sexo y otras investigaciones con el mismo objetivo fueron realizadas. En el área supraorbital, se encontraron valores de 7,92 +/- 1,82 mm y en las áreas laterales de 7,54 +/- 0,98 mm, lo que permite la colocación de implantes de 5 o 6 mm de longitud. En el área del hueso cigomático se obtuvieron,dimensiones de 10,4 +/- 2,35 mm, permitiendo la colocación de los implantes de 8 mm de longitud. En la región periauricular se obtuvieron valores de 2,93 +/- 0,55 mm en la región superior y 3,1 +/- 0,7 mm en la región inferior, mientras que en lo zona perinasal se puede colocar implantes de 4 mm de longitud. Llegamos a la conclusión de que la estructura de los huesos craneomaxilofaciales presenta anchos aceptables para la instalación de implantes; la región periauricular presenta menores dimensiones, con la posibilidad de comunicación intracraneal en zonas sobre el meato auditivo externo...

Evaluation of peri-implant bone density changes in Branemark implants by computer assisted densitometric image analysis (CADIA) / 대한치주과학회지

CADIA(Computer-assisted densitometric image analysis) method is used to analyze bone density changes around the implants. The usefullness and reproducibility of the method was assessed. We tried to find out if there is any possibility to quantitiate and qualitify peri-implant bone density change as time passes. And we concluded that this newly developed linear analysis is efficient for analyzing peri-implant bone density change non-invasively. In this study, 2152 machined Branemark fixtures installed from 1994 to 2002 in the department of Periodontics, Dental hospital of College of Dentistry, Yonsei University were included. Of these fixtures 22 radiographically analyzable failed fixtures were used as experimental group, and 22 successful implants placed in the same patient were used as control group. 1. 57 out of 1635 machined Branemark standard and Mk II implants system failed, the survival rate was 96.5%. And 11 out of 517 machined Branemark Mk III and Mk IV implants system failed, the survival rate was 97.9%. Total survival rate was 96.8%. 2. 22 failed implants were used for the analysis, 10 of which failed before prosthetic treatment due to infection and overheating. 12 failed due to overload after prosthetic treatment, 63.6% of which failed during the early phase of functional loading, i.e. before 1 year of loading. 3. Bone density change values around coronal region of the failed implants were -6.54 +/- 6.35, middle region were -3.53 +/- 5.78, apical region were -0.75 +/- 10.33, resulting in average of -3.71 +/- 8.03. 4. Bone density change values around coronal region of the successful implants were 4.25 +/- 4.66, middle region were 6.33 +/- 5.02, apical region were 9.89 +/-4.67, resulting in average of 6.27 +/- 5.29. 5. There was a statistically significant difference between two groups (p<0.01). In conclusion, the linear analysis method using computer-assisted densitometric image analysis could be a useful method for the analysis of implants, and could be used for future implant researchs.