ISSN : 2234-7550
Cell survival is the result of a balance between programmed cell death and cellular proliferation. Cell membrane receptors and their associated signal transducing proteins control these processes. Of the numerous receptors and signaling proteins, epidermal growth factor receptor (EGFR) is one of the most important receptors involved in signaling pathways implicated in the proliferation and survival of cancer cells. EGFR is often highly expressed in human tumors including oral squamous cell carcinomas, and there is increasing evidence that high expression of EGFR is correlated with poor clinical outcome of common human cancers. Therefore, we examined the antiproliferative activity of gefitinib, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI), in head and neck cancer cell lines. SCC-9, KB cells were cultured and growth inhibition activity of gefitinib was measured with MTT assay. To study influence of gefitinib in cell cycle, we performed cell cycle analysis with flow cytometry. Western blot was done to elucidate the expression of EGFR in cell lines and phosphorylation of EGFR and downstream kinase protein, Erk and Akt. Significant growth inhibition was observed in SCC-9 cells in contrast with KB cells. Also, flow cytometric analysis showed G1 phase arrest only in SCC-9 cells. In Western blot analysis for investigation of EGFR expression and downstream molecule phosphorylation, gefitinib suppressed phosphorylation of EGFR and downstream protein kinase Erk, Akt in SCC-9. However, in EGFR positive KB cells, weak expression of active form of Erk and Akt and no inhibitory activity of phosphorylation in Erk and Akt was observed. The antiproliferative activity of gefitinib was not correlated with EGFR expression and some possibility of phosphorylation of Erk and Akt as a predictive factor of gefitinib response was emerged. Further investigations on more reliable predictive factor indicating gefitinib response are awaited to be useful gefitinib treatment in head and neck cancer patients.
Purpose: The development of a microvascularization is important for the homeostasis of normal bone. Vascular endothelial growth factor (VEGF) is one of the most important factors in vessel formation. The purpose of this study was to examine VEGF-related autocrine growth in periostealderived cells. Materials and methods: Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the periosteal-derived cells were further cultured for 21 days in an osteogenic inductive culture medium containing dexamethasone, ascorbic acid, and β-glycerophosphate. Results: The expression of four VEGF isoforms and VEGFRs was observed in periosteal-derived cells. Treatment with cultures with VEGFR-1 and VEGFR-2 Kinase Inhibitor inhibited osteoblastic differentiation and alkaline phosphatase (ALP) activity of periosteal-derived cells. In addition, exogenous VEGF treatment increased calcium content in the periosteal-derived cells. Conclusion: These results suggest that VEGF might act as an autocrine growth molecule during osteoblastic differentiation of cultured human periosteal-derived cells.
Introduction: Maxillary malignant tumors are primary tumors of the maxillary gingiva, sinus, and palate. The purpose of this study was to research the prognosis and treatment modalities of maxillary malignant tumors. Materials & Methods: For this study, 52 patients, who were treated after being diagnosed for maxillary malignant tumors at the department of OMFS at Yonsei University college of Dentistry from January 1997 till April 2008, were classified, then the prognoses of these patients were evaluated depending on their primary site, histopathology and treatment modalities. The results of this study showed that the most common primary site for maxillary malignant tumors was the gingiva and for histopathology, squamous cell carcinoma. Result & Conclusion: The average follow up period was 32.7 months. In determining prognosis, the most important factors were the control of local site and metastasis of cervical lymph nodes. Therefore, for a better prognosis, a tumor free margin during surgery and a periodic follow up to examine for metastasis to cervical lymph nodes and other organs are necessary.
Purpose: Fibrous dysplasia (FD) is a fibro-osseous disease associated with activating missense mutations of the gene encoding the α-subunit of stimulatory G protein. FD may affect a single bone (called monostotic form) or multiple bones (called polyostotic form). The extent of lesions reflects the onset time of mutation. In this study, cells from monostotic FD in maxilla of a patient were isolated and cultured in vitro for characterization. Materials and Methods: The single cells were released from FD lesion which was surgical specimen from 15 years-old boy. These isolated cells were cultured in vitro and tested their proliferation activity with MTT assay. In osteogenic media, these cells underwent differentiation process comparing with its normal counterpart i.e. bone marrow stromal cells. The proliferated FD cells were detached and transplanted into the dordsal pocket of nude mouse and harvested in 6 weeks and 12 weeks. Results and Summary: FD cells have an increased proliferation rate and poor differentiation. As a result, cells isolated from FD lesion decreased differentiation into osteoblast and increased proliferation capacity. MTT assay presented that proliferation rate of FD cells were higher than control. However, the mineral induction capacity of FD was lesser than that of control. Monostotic FD cells make fewer amounts of bone ossicles and most of them are woven bone rather than lamellar bone in vivo transplantation. In transplanted FD cells, hematopoietic marrow were not seen in the marrow space and filled with the organized fibrous tissue. Therefore, they were recapitulated to the original histological features of FD lesion. Collectively, these results indicated that the FD cells were shown that the increased proliferation and decreased differentiation potential. These in vitro and in vivo system can be useful to test FD cell’s fate and possible
Synovial chondromatosis is an uncommon disease of cartilage transformation of synovial membrane with formation of loose bodies within the joint space. The involvement of temporomandibular joint is very rare. Symtoms include swelling, pain, stiffness of the jaw, and inability to close the jaw. A case involving the temporomandibular joint(TMJ) and non-symptoms is presented.
Purpose: This study was performed to evaluate three-dimensional positional change of the condyle using 3D CT after bilateral sagittal split ramus osteotomy (BSSRO) in skeletal class Ⅲ patients. Patients and methods: Nine patients who underwent BSSRO for mandibular set-back in skeletal class Ⅲ malocclusion without facial asymmetry were examined. Miniplates were used for the fixation after BSSRO. 3-D CT was taken before, immediately after, and 6 months after undergoing BSSRO. After creating 3D-CT images using V-works 4.0TM program, axial plane, coronal plane, & sagittal plane were configured. Three dimensional positional change, from each plane to the condyle, of the nine patients was measured before, immediately after, and 6 months after undergoing BSSRO. Results: 1. The mean value of mandibular set-back for nine mandibular prognathism patients was 7.36 mm (± 2.42 mm). 2. In the axial view, condyle is rotated inward immediately after BSSRO (p < 0.05), comparing with preoperative but outward 6 months after BSSRO comparing with postoperative (p < 0.05). 3. In the axial view, condyle is moved laterally immediately after BSSRO (p < 0.05), comparing with preoperative but regressed 6 months after BSSRO comparing with preoperative (p > 0.05). 4. In the frontal & coronal view, there is changed immediately after and 6 months after BSSRO, comparing with preoperative but no statistical difference. Conclusion: These results indicate that three-dimensional positional change of the condyle in skeletal class Ⅲ patients is observed lateral displacement & inward rotation immediate after BSSRO, but the condyle in 6 months after BSSRO tends to regress to preoperative position.
Submentovertex(SMV) projection shows the base of skull, positions of mandibular condyle and zygomatic arches. We would like to investigate how to use SMV and evaluate its availability for the construciton of the plan for orthognathic surgery of mandible prognathism and asymmetry. Preoperative Surgical Treatment Objective(STO) using SMV was performed to 12 patients, who visited to Seoul National University Bundang Hospital with chief complaints like mandible prognathism or asymmetry from Dec 2007 to Feb 2009. Surgical splint was made of stone model repositioned according to STO using SMV. We estimate the change in skeletal midline and the stability of occlusion through superposition between preoperative and postoperative SMV. It was effective on the amount of mandible movement and the correction of mandibular asymmetry, while the facial asymmetry involved with maxilla was excluded. It was concluded that STO using SMV is available and predictable method for not only the setback of prognathic mandible but also the correction of mandible asymmetry accurately.
Objective: To evaluate the ratio between bone-contact length and inter-segmental length of the rigid fixation screw used in bilateral sagittal split ramus osteotomy (BSSRO) for mandibular setback. Material and Methods: Records of 40 patients with Class III malocclusion were selected. 20 of them had BSSRO, while the other 20 had BSSRO with maxillary LeFort I osteotomy. All of the patients had three noncompressive bicortical screws inserted at the gonial angle through transcutaneous approach. Two screws were inserted antero-posteriorly above inferior alveolar nerve and one screw was inserted below. The lengths of bone-contact and that of inter-segmental part were measured using cone-beam computed tomography. Ratio between these two measured lengths was calculated. Results: Both bone-contact and inter-segmental lengths were longer in BSSRO group than in BSSRO with maxillary LeFort I osteotomy group. Ratio of bone-contact to inter-segmental length was lower in BSSRO group than in BSSRO with Lefort I group. Both bone-contact and inter-segmental lengths were longer at the antero-superior position than at the inferior position. However, their ratio showed little difference. Conclusion: This study suggest that stability of screws in BSSRO group was greater than in BSSRO with Lefort I group. Stability of screws at the antero-superior position was greater than at the inferior position. Ratio of bone-contact to inter- segmental lengths was 0.2 in average.
The purpose of this study was to evaluate clinical and radiographic changes of regular diameter implants placed in the posterior region. A total of 47 standard diameter implants were consecutively placed in the posterior region of 20 partially edentulous patients. The diameters of the implants were 4.1mm (N=35, 74%) and 4.3mm (N=12, 26%), respectively. Peri-implant bone loss and clinical parameters such as mobility, suppuration, swelling, bleeding on probing (BOP) were evaluated at the baseline and?the final follow-up visit. The age of the patients ranged between 24~82 years (mean age: 54.7 years). The cumulative survival rate of the regular diameter implants loaded for a period of 3-24 months (Mean: 11.7±7.9 month) was 100%. The average bone loss over the follow-up was 0.36±0.67 mm. Success rate was 95.7%. Only two implants failed (bone loss exceeding 1mm after 1 year of placement). Some prosthetic complications occurred, such as screw loosening (N=1) and dissolution of cementation material (N=2). The present study describes successful outcome following the use of standard-diameter-implants placed in the posterior region, and further comprehensive maintenance practices and follow-up schedules are required.
Purpose: The purpose of this study was to evaluate the surgical success of bone reconstruction of the severely atrophic maxilla using autogenous block bone onlay graft from the ramus and ilium prior to dental implantation. And we measured the amount of vertical height change Material and Methods: 26 partially edentulous patients(32 case) who needed block onlay bone graft before implant placement in posterior maxillary area from 2002 to 2009 were selected for this study. Patients consisted of 20 males & 6 females and the average of their age was 54.2. Patients who were treated with ramal bone were 19 case and patients who were treated with iliac bone were 11 case. Digital panoramic X-ray was taken at the day of surgery, 3 months and 6 months later after the surgery. Vertical height change & resorption rate of grafted bone were measured with the same X-rays and compared Results: Two out of 32 bone grafts had to be removed because of inflamation at the grafts area(97.3%). The mean of radiographic vertical height change(change rate) of post-op. 3 month was 0.54mm(8.5%)and 6 month was 0.99mm(15.9%). Compairing to intraoral donor site(ramus), iliac bone had more vertical height change(1.18mm) at 6 month after surgery. Conclusions: Within the limit of this study, autogenous block onlay grafts can be considered a promising treatment for severely atrophic maxilla.
There have been reports of successful bone formation with sinus floor elevation by simply elevating the maxillary sinus membrane and filling the sinus cavity below the lifted sinus membrane with a blood clot. But, in a review of the current literature, we found no animal study that substantiated blood clot’s ability in this respect. The aim of this study was to investigate the effect of the method of maxillary sinus floor augmentation using the patient’s own venous blood in conjunction with a sinus membrane elevation procedure. An implant was placed bilaterally in the maxillary sinus of six adult mongrel dogs so that it protruded 8 mm into the maxillary sinus after sinus membrane elevation. On one side of the maxillary sinus, the resultant space between the membrane and the sinus floor was filled with autologous venous blood retrieved from the dog. On the opposite side, the maxillary sinus was left untreated as a control. The implants were left in place for six months. The mean height of the newly formed bone in the sinus was 3.7 mm on the side without venous blood and 3.5 mm on the side with venous blood (p>0.05). There was no difference between the two sides regarding new bone height in the sinus. Our results indicate that filling the space between the lifted sinus membrane and the sinus floor with venous blood has no effect on bone formation around implants placed in the maxillary sinus cavity.
Bisphosphonates are compounds widely used in the treatment of various metabolic and malignant bone disease. Recently, an association between bisphosphonate use and a rare dental condition termed 'osteonecrosis of the jaw(ONJ)' has been reported. Bisphosphonate-related osteonecrosis of the jaw(BRONJ) is rare, but serious, side effect of bisphosphonate therapy in affected patients. It is characterized by poor wound healing and spontaneous intra-oral soft tissue break down, which lead to exposure of necrotic maxillary and mandibular bone. We reviewed 11 patients of BRONJ visited Ajou University Hospital Dental clinic from May 2007 to November 2008. The management of the patients included cessation of bisphosphonate therapy and various surgical restorative procedures and conservative care there after. Aggressive debridement is contraindicated. A new complication of bisphosphonate therapy administration, osteonecrosis of jaws, seems to be developing. The improved results after cessation of the medication should make clinicians reconsider the merits of the rampant use of bisphosphonates, while further investigation is needed to completely elucidate this complication.
Purpose: The purpose of this retrospective report was to analyze long-term survival rate of sintered porous-surfaced dental implant (Endopore Dental Implant system, Innova Corporation, Toronto, ON, Canada). Methods: 61 partially edentulous patients were received a total of 127 Endopore dental implants in the maxilla. Of the 127 implants, 24 implants were restored with individual (ie, non-splinted) crowns, while 103 implants were splinted to other implants. Medical records and radiographs were evaluated and analyzed by the cumulative survival rate, location of implants, implants length and diameter, crown/implant ratio and whether the implant was splinted. Chi squire test was used statistically. Result: Of the 127 implants, 8 implants (6.3%) were removed and and cumulative survival rate was 93.7%. Conclusion: Endopore implants showed satisfactory results after up to 8 years function periods in the edentulous posterior maxilla.
Purpose: The purpose of this study was to evaluate the feasibility of the outfracture osteotomy sinus graft technique with the evaluation of 5-year survival rate of the implants placed in the atrophic edentulous posterior maxillary area. Materials and methods: One hundred and thirteen cases of 96 patients who visited our center from Aug 2004 to July 2009 and were diagnosed as atrophic edentulous maxillary alveolar ridge, were selected and underwent augmentation sinus surgery with outfracture osteotomy technique. Feasibility of the outfracture osteotomy technique was investigated with clinical and radiographic evaluation to assess the survival rate of the total dental implants in augmentation sinus surgery of this new kind. Total fixture number available in follow-up period was 179, in which the lost 10 patients were excluded out of 96 patients. Results: Five-year cumulative survival rate was 97.2% with 5 failures of total 179 fixtures. The average follow-up period was 29 and a half months, with the minimum and maximum follow-up periods of 4 months 21 days and 59 months 14 days, respectively. Conclusion: Traditional infracture technique is a popular method for an augmentation sinus surgery. The authors modified this classical method by outfracturing and readapting the bony window after sinus graft, with excellent treatment results evidenced by high survival rate of 97.2% (174 out of 179 fixtures), which proves the feasibility of the newly-designed outfracture osteotomy sinus graft technique.
Likely to be the most common oral cancer, squamous cell carcinoma(SCC) of the tongue accounts for about 20% of all oral and pharyngeal cancers. SCC of the tongue frequently arises in the lateral border, and if it metastasize, it occurs on submandibular gland and neck lymph nodes. Location of the primary lesions and neck lymph node metastasis affect the prognosis and decrease survival rate of patients with carcinoma of the tongue. The authors experienced the patient with contralateral neck lymph node metastasis of SCC of the tongue. The patient came to our department with chief complaint of elevated lesion on left lateral border of the tongue. The mass was diagnosed as T2N0M0, Stage II invasive SCC of oral tongue. Computed tomography(CT) & magnetic resonance imaging(MRI) which were taken before the operation showed no significant finding of metastasis. Surgical mass removal and preventive neck dissection on the left side were done. While follow up PET/CT, contralateral neck lymph node metastasis( right side, level II) was detected, and re-operation(Rt. side RND) was done. There are few studies concerning the contralateral neck lymph node metastasis related with SCC of the tongue. The purpose of this report is to introduce the uncommon case of contralateral neck lymph node metastasis occurred in the T2-stage of SCC of the tongue treated by surgical resection.
Osteoma is a slow growing benign osteogenic lesion characterized by proliferation of compact or cancellous bone. Osteomas may be classified as peripheral, central, or extraskeletal. Central osteoma arise from the endosteum, pheripheral osteoma from the periosteum, and extraskeletal soft tissue osteoma within a muscle. Peripheral osteoma of the mandible is uncommon. They manifest as asymptomatic, fixed tumors of bony-hard consistency that may be sessile or pedunculated. Radiographically, a well circumscribed round or oval radiopaque mass is seen. Here, we report a case of a huge solitary peripheral osteoma of the buccal posterior mandible in a 40-year-old woman who was otherwise in good health. The patient visited at the dental clinic because the lesion makes esthetic problem. Treatment was performed by surgical esthetic recontouring and histological examination. The patient remains free of recurrence after surgical esthetic recontouring operation
Tumors of the deep lobe of parotid gland are rare. These benign tumors have usually been treated by total parotidectomy, which has functional and esthetic side effects. Recently, there has been a trend for operations of parotid gland benign tumors to be less radical and selective deep lobe parotidectomy has been introduced. This technique preserves the superficial lobe and facial nerve when tumor is located in the deep lobe. Selective deep lobe parotidectomy preserves parotid salivary function, minimizes the incidence of facial nerve damage and gustatory sweating (Frey’s syndrome) and improves cosmetic outcome. We report a case of pleomorphic adenoma of the deep lobe that was successfully treated by selective deep lobe parotidectomy with satisfactory result.