Intra-sinus rigid fixation of a resorbable barrier membrane to repair a large perforation of the sinus membrane: a technical note

A resorbable barrier membrane is commonly used for the repair of perforated sinus membranes during sinus lifting surgeries. However, repairing largescale perforations poses challenges for clinicians as the protection and isolation of graft material remain uncertain. With this technique, we aimed to prevent graft material loss and subsequent sinus-related complications using intra-sinus rigid fixation of the resorbable barrier membrane in cases with a large perforation of the sinus membrane.

The dual-port endoscope-assisted cyst enucleation on the maxillofacial region / 대한악안면성형재건외과학회지

Background@#Endoscope-assisted surgery is a surgical method that has been used in oral and maxillofacial surgical fields. It provides good illumination, clear, and magnified visualization of the operative field. The purpose of this article is to describe the early clinical experiences to conduct minimally invasive surgery with endoscope-assisted enucleation of cysts on the jaw. It appears that this approach may be a superior alternative to the conventional approach. @*Methods@#In this study, 24 patients (9 females, 15 males, average age 41.5) underwent endoscope-assisted cyst enucleation under general anesthesia. All operations were done by one surgeon. The cases were classified depending on whether bone penetration occurred at the cyst site. The cystic lesions were enucleated using an endoscope with a 0°, 1.9 mm diameter, or a 30°, 2.7 mm diameter. Two bony windows were used for the insertion of a syringe for irrigation, curettes, suction tips, sinus blades, surgical drills, and an endoscope. An additional small channel was made for the insertion of endoscopic instruments. @*Results@#The 24 patients who underwent cyst enucleation were regularly observed for 3 to 12 months to evaluate for complications. Although some patients experienced swelling and numbness, these symptoms did not persist, and the patients soon returned to normal and there was no sign of recurrence. @*Conclusions@#The results of this study have suggested the possibility of minimally invasive surgery with endoscopes when it comes to cyst removal in the oral and maxillofacial region. Nevertheless, this study has limitations designed as a preliminary report focusing on the feasibility of endoscope-assisted cyst enucleation in the oral and maxillofacial regions.

The influence of bone graft procedures on primary stability and bone change of implants placed in fresh extraction sockets / 대한악안면성형재건외과학회지

BACKGROUND: This study was to evaluate the effect of bone graft procedure on the primary stability of implants installed in fresh sockets and assess the vertical alteration of peri-implant bone radiographically. METHODS: Twenty-three implants were inserted in 18 patients immediately after tooth extraction. The horizontal gap between the implant and bony walls of the extraction socket was grafted with xenografts. The implant stability before and after graft procedure was measured by Osstell Mentor as implant stability quotient before bone graft (ISQ bbg) and implant stability quotient after bone graft (ISQ abg). Peri-apical radiographs were taken to measure peri-implant bone change immediately after implant surgery and 12 months after implant placement. Data were analyzed by independent t test; the relationships between stability parameters (insertion torque value (ITV), ISQ abg, and ISQ bbg) and peri-implant bone changes were analyzed according to Pearson correlation coefficients. RESULTS: The increase of ISQ in low primary stability group (LPSG) was 6.87 ± 3.62, which was significantly higher than the increase in high primary stability group (HPSG). A significant correlation between ITV and ISQ bbg (R = 0.606, P = 0.002) was found; however, age and peri-implant bone change were not found significantly related to implant stability parameters. It was presented that there were no significant peri-implant bone changes at 1 year after bone graft surgery. CONCLUSIONS: Bone graft procedure is beneficial for increasing the primary stability of immediately placed implants, especially when the ISQ of implants is below 65 and that bone grafts have some effects on peri-implant bone maintenance.

Local anesthesia for mandibular third molar extraction

Mandibular third molar extraction is commonly performed in dental clinics. However, the optimal method of anesthesia has not been established for this procedure. The conventional inferior alveolar nerve block is the most widely used method. However, its success rate is not high and it may lead to complications, such as aspiration and nerve injury. Therefore, various anesthesia methods are being investigated. Articaine has been proven to be efficacious in a number of studies and is being used with increasing frequency in clinical practice. In this review article, we will briefly review various local anesthesia techniques, anesthetics, and a computer-controlled local anesthetic delivery (CCLAD) system, which reduces pain by controlling the speed of drug injection, for mandibular third molar extraction.

Multiple brain abscesses treated by extraction of the maxillary molars with chronic apical lesion to remove the source of infection / 대한악안면성형재건외과학회지

BACKGROUND@#Brain abscess is a life-threatening condition that occurs due to complications during a neurosurgical procedure, direct cranial trauma, or the presence of local or distal infection. Infection in the oral cavity can also be considered a source of brain abscess.CASE PRESENTATION: A 45-year-old male patient was transported with brain abscess in the subcortical white matter. Navigation-guided abscess aspiration and drainage was performed in the right mid-frontal lobe, but the symptoms continued to worsen after the procedure. A panoramic radiograph showed alveolar bone resorption around the maxillary molars. The compromised maxillary molars were extracted under local anesthesia, and antibiotics were applied based on findings from bacterial culture. A brain MRI confirmed that the three brain abscesses in the frontal lobe were reduced in size, and the patient's symptoms began to improve after the extractions.@*CONCLUSION@#This is a rare case report about multiple uncontrolled brain abscesses treated by removal of infection through the extraction of maxillary molars with odontogenic infection. Untreated odontogenic infection can also be considered a cause of brain abscess. Therefore, it is necessary to recognize the possibility that untreated odontogenic infection can lead to serious systemic inflammatory diseases such as brain abscess. Through a multidisciplinary approach to diagnosis and treatment, physicians should be encouraged to consider odontogenic infections as a potential cause of brain abscesses.

The preliminary study for three-dimensional alveolar bone morphologic characteristics for alveolar bone restoration / 대한악안면성형재건외과학회지

BACKGROUND@#The concept of the ideal morphology for the alveolar bone form is an important element to reconstruct or restore the in maximizing esthetic profile and functional alveolar bone restoration. The purpose of this preliminary study is to evaluate the normal alveolar bone structure to provide the standard reference and guide template for use in diagnosing for implant placement, determining the correct amount of bone augmentation in actual clinical practice and producing prostheses based on three-dimensional imaging assessment of alveolar bone.@*METHODS@#This study was included 11 men and 11 women (average age, 22.6 and 24.5 years, respectively) selected from among 127 patients. The horizontal widths of alveolar bone of maxilla and mandible were measured at the crestal, mid-root, and root apex level on MDCT (multi-detector computed tomography) images reconstructed by medical imaging software. In addition, tooth dimensions of the central incisors, canines, second premolars, and first molars of maxilla and mandible, including the horizontal width of the interdental alveolar bone crest, were also measured and statistically analyzed.@*RESULTS@#The horizontal alveolar bone width of the palatal side of maxilla showed a distinct increment from the alveolar bone crest to the apical region in both anterior and posterior areas. The average widths of the maxillary alveolar ridge were as follows: central incisor, 7.43 mm; canine, 8.91 mm; second premolar, 9.57 mm; and first molar, 12.38 mm. The average widths of the mandibular alveolar ridge were as follows: central incisor, 6.21 mm; canine, 8.55 mm; second premolar, 8.45 mm; and first molar, 10.02 mm. In the buccal side, the alveolar bone width was not increased from the crest to the apical region. The horizontal alveolar bone width of an apical and mandibular border region was thinner than at the mid-root level.@*CONCLUSIONS@#The results of the preliminary study are useful as a clinical guideline when determining dental implant diameter and position. And also, these measurements can also be useful during the production of prefabricated membranes and customized alveolar bone scaffolds.

Importance of Oral Environment for Environmental Hormones Interaction with Human Body for Future Research

There is increasing evidence that the environmental hormones may adversely affect the human body. The human reproductive system misrecognizes some of these endocrine disruptors with consequences to reproductive cell differentiation. Therefore, studies on the safety of these substances have been widely carried out to develop the science to create effective legislation to limit or prevent their use or require the development of inert, alternative substances. A few studies have reported that the oral cavity is the pathway for absorption of these substances released from plastic products or environmental hormone substances. This review suggests that the oral environment is vulnerable to exposure to environmental hormones and introduces supporting literature.

Effects of nerve cells and adhesion molecules on nerve conduit for peripheral nerve regeneration

BACKGROUND: For peripheral nerve regeneration, recent attentions have been paid to the nerve conduits made by tissue-engineering technique. Three major elements of tissue-engineering are cells, molecules, and scaffolds. METHODS: In this study, the attachments of nerve cells, including Schwann cells, on the nerve conduit and the effects of both growth factor and adhesion molecule on these attachments were investigated. RESULTS: The attachment of rapidly-proliferating cells, C6 cells and HS683 cells, on nerve conduit was better than that of slowly-proliferating cells, PC12 cells and Schwann cells, however, the treatment of nerve growth factor improved the attachment of slowly-proliferating cells. In addition, the attachment of Schwann cells on nerve conduit coated with fibronectin was as good as that of Schwann cells treated with glial cell line-derived neurotrophic factor (GDNF). CONCLUSIONS: Growth factor changes nerve cell morphology and affects cell cycle time. And nerve growth factor or fibronectin treatment is indispensable for Schwann cell to be used for implantation in artificial nerve conduits.

Effects of airway evaluation parameters on the laryngeal view grade in mandibular prognathism and retrognathism patients

BACKGROUND: Failure to maintain a patent airway can result in brain damage or death. In patients with mandibular prognathism or retrognathism, intubation is generally thought to be difficult. We determined the degree of difficulty of airway management in patients with mandibular deformity using anatomic criteria to define and grade difficulty of endotracheal intubation with direct laryngoscopy. METHODS: Measurements were performed on 133 patients with prognathism and 33 with retrognathism scheduled for corrective esthetic surgery. A case study was performed on 89 patients with a normal mandible as the control group. In all patients, mouth opening distance (MOD), mandibular depth (MD), mandibular length (ML), mouth opening angle (MOA), neck extension angle (EXT), neck flexion angle (FLX), thyromental distance (TMD), inter-notch distance (IND), thyromental area (TMA), Mallampati grade, and Cormack and Lehane grade were measured. RESULTS: Cormack and Lehane grade I was observed in 84.2%, grade II in 15.0%, and grade III in 0.8% of mandibular prognathism cases; among retrognathism cases, 45.4% were grade I, 27.3% grade II, and 27.3% grade III; among controls, 65.2% were grade I, 26.9% were grade II, and 7.9% were grade III. MOD, MOA, ML, TMD, and TMA were greater in the prognathism group than in the control and retrognathism groups (P < 0.05). The measurements of ML were shorter in retrognathism than in the control and prognathism groups (P < 0.05). CONCLUSIONS: Laryngoscopic intubation was easier in patients with prognathism than in those with normal mandibles. However, in retrognathism, the laryngeal view grade was poor and the ML was an important factor.

Bilateral dentigerous cysts that involve all four dental quadrants: a case report and literature review

Dentigerous cysts are common odontogenic cysts that are associated with the crown of the tooth and typically develop from single lesions. Bilateral and multiple dentigerous cysts are very rare and occur in patients with syndromic conditions. This paper presents a case report of a 15-year-old male patient that experienced non-syndromic bilateral dentigerous cysts that simultaneously occurred in all four dental quadrants around the unerupted third molars. Clinicians should confirm the extent of cystic lesions using a panoramic view and computed tomography, and should keep the possibility of bilateral dentigerous cysts in mind as a potential diagnosis, even in a non-syndromic patient.

Preliminary evaluation of a three-dimensional, customized, and preformed titanium mesh in peri-implant alveolar bone regeneration

OBJECTIVES: The purpose of this preliminary study is to evaluate the effectiveness of a customized, three-dimensional, preformed titanium mesh as a barrier membrane for peri-implant alveolar bone regeneration. MATERIALS AND METHODS: Ten patients were recruited for this study. At the time of implant placement, all patients had fenestration or a dehiscence defect around the implant fixture. A mixture of particulate intraoral autologous bone and freeze-dried bone allograft was applied to the defect in a 1 : 1 volume ratio and covered by the preformed titanium mesh. A core biopsy specimen was taken from the regenerated bone four months postoperatively. Patients were followed for 12 months after the definitive prosthesis was placed. RESULTS: Satisfactory bone regeneration with limited fibrous tissue was detected beneath the preformed titanium mesh. Histologic findings revealed that newly formed bones were well-incorporated into the allografts and connective tissue. New growth was composed of approximately 80% vital bone, 5% fibrous marrow tissue, and 15% remaining allograft. All implants were functional without any significant complications. CONCLUSION: The use of preformed titanium mesh may support bone regeneration by maintaining space for new bone growth through its macro-pores. This preliminary study presents the efficacy of a preformed titanium mesh as a ready-to-use barrier membrane around peri-implant alveolar bone defect. This preformed mesh is also convenient to apply and to remove.

Anterior maxillary defect reconstruction with a staged bilateral rotated palatal graft

PURPOSE: In the anterior maxilla, hard and soft tissue augmentations are sometimes required to meet esthetic and functional demands. In such cases, primary soft tissue closure after bone grafting procedures is indispensable for a successful outcome. This report describes a simple method for soft tissue coverage of a guided bone regeneration (GBR) site using the double-rotated palatal subepithelial connective tissue graft (RPSCTG) technique for a maxillary anterior defect. METHODS: We present a 60-year-old man with a defect in the anterior maxilla requiring hard and soft tissue augmentations. The bone graft materials were filled above the alveolar defect and a titanium-reinforced nonresorbable membrane was placed to cover the graft materials. We used the RPSCTG technique to achieve primary soft tissue closure over the graft materials and the barrier membrane. Additional soft tissue augmentation using a contralateral RPSCTG and membrane removal were simultaneously performed 7 weeks after the stage 1 surgery to establish more abundant soft tissue architecture. RESULTS: Flap necrosis occurred after the stage 1 surgery. Signs of infection or suppuration were not observed in the donor or recipient sites after the stage 2 surgery. These procedures enhanced the alveolar ridge volume, increased the amount of keratinized tissue, and improved the esthetic profile for restorative treatment. CONCLUSIONS: The use of RPSCTG could assist the soft tissue closure of the GBR sites because it provides sufficient soft tissue thickness, an ample vascular supply, protection of anatomical structures, and patient comfort. The treatment outcome was acceptable, despite membrane exposure, and the RPSCTG allowed for vitalization and harmonization with the recipient tissue.

Evaluation of the feasibility of bony window repositioning without using a barrier membrane in sinus lateral approach

INTRODUCTION: In the lateral window approach for a maxillary sinus bone graft, there has been considerable controversy regarding the placement of a barrier membrane over the osteotomy site. In particular, when there is no damage to the Schneiderian membrane, clinicians should decide whether to use a barrier membrane or not, considering the benefits and costs. This study presents the clinical cases to demonstrate that only repositioning the detached window can lead to satisfactory bony healing of the grafted material without using a barrier membrane in the lateral approach for a maxillary sinus bone graft. MATERIALS AND METHODS: Five consecutive patients were treated with the same surgical procedures. After performing the antrostomy on the lateral maxillary wall using a round carbide bur and diamond bur, the bony window was detached by a gentle levering action. After confirming no perforation of the Schneiderian membrane, the grafting procedure was carried out the detached window of the lateral maxillary wall was repositioned over the grafted material without using a barrier membrane. A gross examination was carried out at the postoperative 6 month re-entry, and the the preoperative and postoperative dental computed tomography (CT) at re-entry were compared. RESULTS: All the procedures in the 5 patients went on to uneventful healing with no complications associated with the bone graft. Satisfactory bone regeneration without the interference of fibrous tissue on the gap between the repositioned window and lateral wall of the maxillary sinus was observed in the postoperative 6 month re-entry. The CT findings at re-entry revealed the, reconstruction of the external cortical plate including repositioned bony window. In addition, the loss of the discontinuity of the lateral maxillary wall was confirmed. CONCLUSION: This preliminary report showed that the detached window, which was just repositioned on the grafted material, could function as a barrier membrane in the lateral approach for a maxillary sinus bone graft. Therefore additional morphometric and histologic studies will be needed.

Alterations of Gene Expression by Beta-tricalcium Phosphate in Osteoblast-like MG63 Cells

A Multicenter Retrospective Study of Outpatient Intravenous Sedation for Dental Treatments

The BMPs expression and histomorphometric study of beta-TCP /rhBMP-2 Grafting on the rabbit cranial bone defects

OBJECTIVE: The Purpose of the study was to investigate the bone morphogenic protein expression of rhBMP-2(recombinant human bone morphogenic protein-2) as singnaling molecule and beta-TCP(Tricalcium phosphate) as a bone substitute and carrier medium of rhBMP-2. MATERIALS AND METHODS: 16 rabbits divided into 2 group of each 8 rabbit. Two standardized bone defect, round bilateral defect was made in the cranium of the 8 rabbit of first group, and was grafted with 150~500micrometer diameter beta-TCP 0.25g in one side, which was soaked with rhBMP-2, and autogenous bone was grafted on another side as a positive control. Second group of 8 rabbit, only beta-TCP was grafted with same size and same manner. After 2, 4, 8, and 12 weeks, specimen was taken for microscopic immunohiostochemical and histomorphometric analysis. RESULT: Grafting beta-TCP with rhBMP show the early formation of the bone regenerative factor (BMP-4) and more quantity of new bone formation than only use of beta-TCP (8,12 week), even show less new bone formation than autogenous bone. CONCLUSION: The experimental study result that beta-TCP graft combination with rhBMP-2 as a delivery system is an effective with osteoinductive capacity and biodegradable properties, so that provide clinical availibility of composite use in reconstruction of bony defect.

Etiology and Patterns of Maxillofacial Fractures in 518 patients in Korea

PURPOSE: Different patterns in the causes of maxillofacial injury are thought to correlate with socioeconomic status and regional environment. This study investigated maxillofacial fractures in order to analyze maxillofacial trauma characteristics and the relationship between the causes and injury patterns in Korea. MATERIAL AND METHODS: A total of 518 patients with maxillofacial fractures who were treated at the Seoul National University Boramae Hospital between 1996 and 2004 were retrospectively analyzed. Data were obtained from the patients' medical records and radiographs. The male to female ratio in the patient group was 2.78:1, and the mean age was 32.3 years. RESULTS: Midfacial fractures were the most common location of injury (46.1%). The most common etiologic factor was an activity associated with daily life (42.6%) including falls, stumbling, and collisions. The second most common cause was assault (32.4%), followed by traffic accidents (13.7%). In the case of midfacial fractures and mandibular fractures, assault was the most common etiologic factor, whereas in the case of alveolar bone fractures, activities associated with daily life were the most common cause. With regard to age groups, assault was the most common cause for patients between 10 and 39 years old and an activity associated with daily life was the most common cause in those under 10 years and over 40 years. CONCLUSIONS: This study concluded that activities associated with daily life and assault causes a large proportion of Korean maxillofacial injuries and that preventive measures should be implemented in order to minimize these risks.

The mRNA expression of MMP-1, TIMP-1, TGF-beta1 in gingival keratocytes from gingival hyperplasia induced by cyclosporine A

PURPOSE: Cyclosporine A (CsA) is a versatile immunosuppresive agent used to prevent graft rejection syndrome and treat autoimmune disease. One of the major side effects associated with CsA is the abnormal gingival hyperplasia. The purpose of this study was to investigate the relationship between the mRNA expression of the MMP-1, TIMP-1, and TGF-beta1 and the concentration of CsA in cultured human gingival keratinocytes. MATERIALS AND METHODS: Gingival keratocytes were obtained from gingival tissues of 4 healthy donors. The cultured gingival keratocytes were incubated with increasing concentrations of CsA (0-2000 ng/ml) for 24 hours and the expression of MMP-1, TIMP-1, and TGF-beta1 were determined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The expressions of MMP-1 and TGF-beta1 were not significantly different according to the concentrations of CsA. The expression of TIMP-1 was significantly increased at the CsA concentration of 500 ng/ml. CONCLUSION: We concluded that the gingival hyperplasia induced by CsA was more related with TIMP-1 than MMP-1 or TGF-beta1 on gingival collagen metabolism in patients treated with CsA.

The effects of beta-TCP/rhBMP-2 on bone formation in osteoblast-like cells induced from bone marrow-derived mesenchymal stem cells

The present study aimed to investigate the osteogenic potentials of differentiated osteoblast-like cells (DOCs) induced from bone marrow-derived mesenchymal stem cells (MSCs) on beta-tricalcium phosphate (beta-TCP) with recombinant human bone morphogenetic protein (rhBMP-2) in vitro. Osteoblast differentiation was induced in confluent cultures by adding 100 nM dexamethasone, 10 mM beta-glycerophosphate, 50 mM L-ascorbic acid. The Alizarin red S staining and reverse transcriptase-polymerase chain reaction (RT-PCR) were perfomed to examine the mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN), receptor activator for nuclear factor kappaB ligand (RANKL), runt-related transcription factor 2 (RUNX2), collagen-I (COL-I). There were no significant differences in the osteogenic potentials of DOCs induced from MSCs on beta-TCP(+/-). According to the incubation period, there were significant increasing of Alizadin red S staining in the induction 3 weeks. The mRNA expression of ALP, RUNX2, and RANKL were higher in DOCs/beta-TCP(-) than DOCs/beta-TCP(+). According to rhBMP-2 concentrations, the mRNA expression of BSP was significantly increased in DOCs/beta-TCP(+) compared to that of DOCs/beta-TCP(-) on rhBMP 10 ng/ml. Our study presented the beta-TCP will have the possibility that calcium phosphate directly affect the osteoblastic differentiation of the bone marrowderived MSCs.

The experimental study of the bone regeneration on rabbit maxillary sinus grafting with beta-TCP

PURPOSE:Maxillay sinus grafting is an effective treatment procedure to improve bone height in the posterior maxillar area for implant installation. Beta-tricalciumphosphate(beta-TCP) was introduced to be grafting substitute material, providing a reasonable bio-degradation time, no need for harvesting procedure. The purpose of this study is to evaluate bone healing and regeneration phase using histomorphometric and immunohistochemical analysis. MATERIAL AND METHODS:Sixteen rabbits were divided into 4 groups. Bi-lateral maxillary sinus membranes were elevated at each rabbits, beta-TCP was augmented in left sinus, autogenous bone was augmented in right sinus. The rabbits were sacrificed at 2, 4, 8 and 12 weeks. We investigated the bone regeneration and growth factor expression. RESULTS: 1. The mean new bone volume formation was 28.99+/-6.55%, 49.54+/-5.47%, 69.09+/-8.90% in autogenous grafted area, and 22.86+/-5.56%, 24.00+/-4.09%, 34.11+/-3.37% in beta-TCP area at 4, 8, 12 weeks. Therefore, new bone formation in autogenous bone was significantly higher than beta-TCP (p<0.05). 2. The BMP 2/4 expression in autogenous bone grafted area was higher at 4, 8 weeks. 3. There was no difference in expression pattern of BMP-7/PDGF/VEGF during grafted bone regeneration. CONCLUSION:The authors we conclude that the autogenous bone graft was faster than beta-TCP in bone regeneration, and the BMP 2/4 were more important in graft bone regeneration.