Tissue engineering has been rapidly developed in oral and maxillofacial reconstruction. Biocompatible scaffold from chemically composites seeded with stem cells is essential and several growth factors for bone formation and angiogenesis are also required. To overcome limited activity of new bone formation with scaffolds, several biomechanical stimulation methods on cells have been made to grow cells in scaffold. Several bioreactors have been developed for real tissue growth in culture laboratory. In addition to biological stimulants like BMP, growth factors and exogenous drugs, biomechanical stimulation technique has also been known as an effective method in cell differentiation. We developed our own bioreactor with tensile mechanical strains. Then we tested with it for detection of suitable biomechanical effect on the cell differentiation and proliferation. And we also compared the results with the effect of low intensity pulsed ultrasound (LIPUS). Mechanical strain group showed more rapid reaction with cell differentiation and proliferation than non-mechanical strain group. Mechanical strain groups stimulated with 0.5∼0.7Hz for 6 hours and 8 hours showed more active cell differentiation than the group with 0.5∼0.7Hz for 2.5 hours tensile strain stimulation. Group of LIPUS also showed more rapid reaction in cell differentiation and proliferation. LIPUS with 3MHz showed more cell reaction than the LIPUS group with 1MHz. Our results showed the positive effect on differentiation and proliferation of cell with mechanical tensile strain, LIPUS both. Key words : Osteogenic activity, Tensile strain, Low intensity pulsed ultrasound

Herbal medicine has been the basis for medical treatments through much of human history, and such traditional medicine is still widely practiced today. Modern medicine makes use of many plant-derived compounds as the basis for pharmaceutical drugs. In traditionally, Achyranthes aspera, Safflower (Carthamus tinctorius) seed and Acanthopanax senticosus have been used for the treatment and prevention of bone-related diseases. In this study, we investigated the pharmacological effect of mixture of Achyranthes aspera, Safflower (Carthamus tinctorius) seed and Acanthopanax senticosus and the other herbs. Two types of enzymes were used to enhance the extraction components of amino acid, mineral content, free sugar, and flavor recovery in extracting natural herbal mixtures(NME). We evaluated regulation of osteogenic differentiation in human bone marrow mesenchymal stem cells using alkaline phosphatase staining, alizarin red S staining and RT-PCR. The CCK-8 assay indicated that NME had no cytotoxicity but increased cell survival. In addition, NME promoted the mineralization and expression of osteogenic differention marker genes in human bone marrow mesenchymal stem cells. Therefore, NME has an effect of promoting proliferation and osteogenic differentiation of human mesenchymal stem cell. Key words : NME extract, Human bone-marrow mesenchymal stem cells, Osteogenic differentiation, APA

Mucinous adenocarcinoma (MAC) refers to a malignant neoplasm that belongs to a subtype of adenocarcinoma which produces mucin. The World Health Organization has classified MAC as a tumor of salivary gland origin and it is extremely rare. Therefore, its characteristics are not well-known. This study reports a case of MAC of minor salivary gland origin, which occurred in the oral commissure of an 82-year-old female patient, and a systematic review on existing cases of MAC of salivary origin. Based on the study’s findings, it is safe to assume that the occurrence of lymph node metastasis is an important factor in determining the prognosis of patients with MAC. Key words : Mucinous adenocarcinoma, Lymphatic metastasis, Prognosis

Benign fibro-osseous lesions are demonstrated as a group of conditions, which normal bone is replaced by a connective tissue matrix that gradually develops cemento-osseous tissue and include developmental lesion, reactive lesion, dysplasia and tumor. Cemento-osseous dysplasia is one of benign fibro-osseous lesions, which is non-neoplastic process. Histologic features of cemento-osseous dysplasia are admixtures of bone and cementoid materials in a fibrous stroma. Cemento-osseous dysplasia associated with traumatic bone cysts has infrequently been reported. Traumatic bone cyst is a pseudocyst that may befound in both the jaws and the long bones. Though blockage of interstitial fluid drainage orvenous obstruction may be the cause of traumatic bone cyst, the exact pathogenesis of traumatic bone cysts is unknown. Melrose et al. was the first to report association of cemento-osseous dysplasia and traumatic bone cystsin their series. It is assumed that different mechanism is involved in cyst formation in these cases. This report presents review of literature and describes a case of focal cemento-osseous dysplasia associated with traumatic bone cyst of the mandible and its surgical treatment. Key words : Traumatic bone cyst, Cemento-osseous dysplasia, Mandible

Pseudolymphoma or benign lymphoid hyperplasia is an uncommon benign lymphoproliferative lesion that occurs very ralely in the oral mucosa, most commonly in the hard palate. It is important to differentiate between malignant lymphoma and pseudolymphoma with similar clinical and morphological symptoms. Clinically, pseudolymphoma is a firm, painless, nonulcerated, nonfluctuant, slowly growing mass or swelling on the one side of the palate. However, lymphoma at hard palate is unilateral, and some are hard, painful, or show evidence of bone destruction. The treatment of pseudolymphoma is local excision. Key words : Pseudolymphoma, benign lymphoid hyperplasia, Palate

Basaloid squamous cell carcinoma (BSCC) is a rare and aggressive variant of squamous cell carcinoma arising in various anatomical sites. This article describes a case history of BSCC of the floor of mouth with mandibular involvement, and further discusses the appropriate management of such case with reference to the literature review. A 52-year-old male patient was referred to our clinic from another university hospital. Segmental mandibulectomy with supraomohyoid neck dissection and mandible reconstruction with left fibular free flap under general anesthesia was performed, followed by radiotherapy. Histopathological examination on the tumor lesion revealed features of squamous cell carcinoma with comedo-type necrosis. A diagnosis of BSCC was given by the oral pathology specialist. Basaloid squamous cell carcinoma (BSCC) is a biphasic variant of SCC with both basaloid and squamous cell histology. A recent report showed that there is no significant difference in the prognosis. Due to the lack of accumulated research, close follow-up and continuous research are deemed necessary. Treatment that focuses on the stage of the tumor is appropriate. A periodic follow-up observation is also very important due to the occurrence of distant metastasis to the lungs. Key words : Basaloid squamous cell carcinoma, Segmental mandibulectomy, Fibular free flap

Juvenile xanthogranuloma (JXG) is a benign histiocytosis that occurs in the pediatric population. Cutaneous JXG is the most common form, while extracutaneous lesions, including oral JXG, is extremely rare. Cutaneous JXG can occur as multiple lesions and may have systemic visceral involvement, but this is not seen in oral JXG. In this case, we report a solitary oral JXG at the gingiva in a 3-year old male. Key words : Juvenile xanthogranuloma, Oral cavity, Histiocytosis

Lymphomatoid granulomatosis (LYG) is an uncommon Epstein-Barr virus (EBV)-associated B-cell lymphoproliferative disorder distinct from lymphoma. LYG primarily occurs in the lung with or without accompanied lesions in the skin, central nervous system, kidney, gastrointestinal tract, nose, eyes, liver and oral cavity. Solitary extrapulmonary LYG is extremely rare, and whether solitary lesions progress onto pulmonary development and dysfunction is controversial. Herein, we report a case on a solitary LYG in the maxilla gingiva with bone exposure in a patient who had been taking methotrexate for rheumatoid arthritis. Key words : Lymphomatoid granulomatosis, Methotrexate, Maxilla, Epstein-Barr virus

Myelolipoma is a benign tumor consists of mature adipocyte and hematopoietic elements. Mostly, this tumor locates in adrenal gland and it also can be found in extra-adrenal area. However, intraosseous myelolipoma is extremely rare. The etiology of this tumor is unclear but some hypothesis proposed that altered mesenchymal stem cell functioning and hormonal events act together in the pathogenesis of myelolipoma. With radiographic view, myelolipoma shows similar characteristics of other fat-containing tumors. The histopathologic examination is necessary for the definite diagnosis. This case report includes a patient with intraosseous myelolipoma of maxilla and mandible and literature review about the clinical, histopathologic, and radiologic features of myelolipoma. Key words : Myelolipoma, Radiographs, Histology

Brain abscesses caused by odontogenic infection are a rare and life-threatening condition. When dental patients show neurological symptoms such as decreased consciousness, a brain abscess should be considered as a possible diagnosis. We reported that a 65-year-old man visited the emergency room because of left facial edema, high fever, limitation of mouth opening and decreased consciousness. CT, bone scan, and microbiologic examination revealed that the brain abscess originated from left mandibular osteomyelitis with an apical lesion in tooth #36. It was hard to diagnose the location of odontogenic infection. Because there were no evidence of submandibular abscess which is a common path of mandibular posterior infection, early diagnosis was difficult. MRI and radiographs such as facial CT and brain CT revealed procedure that inflammatory findings progressed through the coronoid process, the temporal space, into the subdural space. We compared the present case to previous cases, articles published after the year 2000 in Korea and abroad were investigated. The patient was treated successfully with extraction of causative teeth, drainage surgery, intravenous antibiotics by collaboration between the department of oral maxillofacial surgery and neurosurgery. It is difficult to diagnose brain abscess because central nervous system can be infected by various pathway. As shown in this case, patients with a brain abscess caused by a dental infection should be diagnosed and treated with a multidisciplinary approach. Key words : Brain abscess, Odontogenic infection, Osteomyelitis

Recently, a number of recent reports have reported cases of bone marrow defect (BMD) in the mandible. Among the diseases seen by BMD in radiographs, focal osteoporotic bone marrow defect(FOBMD) is asymptomatic, which is discovered incidentally and localized radiolucency. Because it varies in size, shape, trabeculae and border definition, it needs to biopsy to differential diagnose other intraosseous lesions that show radiological bone marrow defects. This cases report discusses the pre-operation considerations in patients planning to implant the mandible and suspected to have FOBMD in radiographs. The following 4 cases in Dental Hospital of Wonkwang University were taken in panoramic and Cone beam computed tomography(CBCT). In all cases, there were radiolucent lesion diagnosed with FOBMD under radiologic differential diagnosis. In three of cases the implant were placed without treatment plan change and one case changed the treatment plan with removable partial denture. BMD is anatomical state that can affect primary stability of implant fixture. During implant placement, it can lead to unexpected results that fixture is fallen into BMD and the nerve may be damaged after implant fixture removal to cause hyperesthesia. Preoperative diagnosis of these lesions by differential diagnosis with panoramic and CBCT can prevent the complications by changing the treatment plan or paying attention to the manipulation during surgery. Key words : Bone Marrow Diseases, Mandibular Prosthesis Implantation, Differential Diagnosis

This study was conducted as part of a series of studies to introduce the Convolutional Neural Network(CNN) into the diagnostic field of osteoporosis. The purpose of this study was to compare the results when testing Digital Radiography(DR) and Computed Radiography(CR) panoramic radiographs by CNN that were trained by DR panoramic radiographs. The digital panoramic radiographs of females who visited for the purpose of diagnosis and treatment at Chonnam National University Dental Hospital were taken. Two Oral and Maxillofacial Radiologists were selected for the study to compare the panoramic radiographs with normal and osteoporosis images. Among them, 1068 panoramic radiographs of females{Mean [± standard deviation] age: 49.19 ± 21.91 years} obtained by DR method were used for training of CNN. 200 panoramic radiographs of females{Mean [± standard deviation] age: 63.95 ± 6.45 years} obtained by DR method and 202 panoramic radiographs of females{Mean [± standard deviation] age: 62.00 ± 6.86 years} obtained by CR method were used for testing of CNN. When the DR panoramic radiographs were tested, the Accuracy was 92.5%. When the CR panoramic radiographs were tested, the Accuracy was 76.2%. It can be seen that the CNN trained by DR panoramic radiographs is suitable to be tested with the same DR panoramic radiographs. Key words : CNN, Osteoporosis, DR panoramic radiographs, CR panoramic radiographs