Ameloblastoma is an odontogenic tumor characterized by various sites of metastasis, malignant transformation, and a high recurrence rate over time. Ameloblastic carcinoma(AC) is the term reserved for an ameloblastoma with histologic evidence of malignancy in the primary tumor. AC is classified into two types: most ACs occur de novo, and only few cases of malignant transformation of ameloblastoma become apparent. Here, we report a case of AC, arising from recurrent acanthomatous ameloblastoma on the maxillary sinus, in a 60-year-old male patient. The mass was first diagnosed as acanthomatous ameloblastoma; subsequently, surgical curettage was performed thrice while partial maxillectomy was performed twice. On the fifth recurrence, the tumor was identified as AC.

Pseudosarcomatous fibromatosis (PSF), also known as nodular fasciitis and pseudosarcomatous fasciitis, is a rare, benign proliferation of fibroblasts and myofibroblasts. It is often misdiagnosed as sarcoma because of its characteristic rapid progression, leading to unnecessary and aggressive surgery. Here we report a case of PSF found in the masseter muscle in a 26-year-old female. The mass that could be misdiagnosed because of its rapid growth characteristics was surgically excised by an intraoral approach and diagnosed as PSF by histopathologic examinations.

Ameloblastoma is a benign odontogenic tumour of epithelial origin and comprises 1% of maxillomandibular tumors or cysts. The incidence of pathological changes such as ameloblastoma from the follicle of impacted third molar was reported to have low incidence. However, there are many reports that asymptomatic third molars are related with various pathological conditions. A case of ameloblastoma secondary to third molar extraction and subsequent sagittal split ramus osteotomy (SSRO) had not been reported. At the right ramus area, radiolucent lesion had been noted at 6 years after the surgical extraction of the third molar followed by SSRO for the mandibular prognathism. The lesion was proved to be the basal cell type ameloblastoma. There had been no significant bony lesion before or 1 year after the SSRO. The tumour was successfully removed and there was no evident recurrence at 4 year of the follow up after the removal of the ameloblastoma. There are some reports suggesting the pathologic potential of the pericoronal tissues of impacted third molars to develop odontogenic keratocysts and ameloblastomas. The current case reports a rare possibility of ameloblastic change at the site of uneventful healing after third molar extraction and orthognathic surgery.

Carcinoma ex pleomorphic adenoma (Ca ex PA) is an uncommon malignant tumor. It is an aggressive salivary carcinoma, arising from a primary or recurrent benign pleomorphic adenoma (PA). The most common clinical presentation of Ca ex PA is a firm mass in the parotid gland. Here we report a case of Ca ex PA, arising from a recurrent benign PA in the right parotid gland, in a 70-year old female patient. The lesion was first diagnosed as a PA and a superficial parotidectomy was performed. Re-operation was performed for recurrent PA. The second recurrence was diagnosed as Ca ex PA.

This study was performed to improve the efficiency of guided bone regeneration by adapting the tissue-engineered bone regeneration approach. The PHBV-collagen nonofibrous membranes cultured with rat calvarial periosteum derived cells in osteogenic culture medium for 7 days were applied to 5 x 2mm size artificial rat tibial defects for 3weeks and evaluated its efficiency as an alternative cell engineered membrane for effective guided bone regeneration by routine histological observation. The defects covered with cell attached PHBV-collagen nanofibrous membrane complexes showed favorable bone repair compared to both membrane non-covered control and membrane only covered group without specific side effects. These findings suggest that the favorable guided bone generation can be achieved by adapting the tissue engineered bone regeneration approach using PHBV-Collagen nanofibrous membrane scaffold.

The PHBV nonofibrous membrane fabricated by electron-spinning method for tissue engineered bone regeneration scaffold was evaulated in terms of cellular prolieration and cryopreservation efficiency. The rat calvarial periosteum derived primary cells were cultured with PHBV nanofibrous membranes and analyzed the cellular proliferation and differention fashion and cryopreservation potential by in vitro MTT assay as well as ALP staining and Alizarine red staining with or without cryopreservation for 2 weeks. The rat calvarial periosteum derived primary cells cultured with PHBV nonofibrous membrane showed favorable proliferation and alkaline phosphatase activity with numerous mineral nodule formation regardless of cryopreservation, even though its efficiency was slightly decreased in cryopreserved condition. These findings suggest that PHBV nanofibrous membrane can be applicable as an efficient cell engineered membrane for guided bone regeneration or scaffold for tissue engineered bone regeneration.

Previous in vi tro studies demonstrated that H202 or carbamide peroxide cou ld penetrate i nto pul p chambers through enamel and dentin (Benetti et a l., 2004; G okay et a l. , 2004‘ Suli eman et al .. 2005) ‘ Recently. Lee et al.(2006) demonstrated that H20Z enhanced the diffe rentiation of odontoblast like cell line, whereas it inhibited osteogenic diffe rentiation in pre 。steobl astic cell line, as seen by its efl"ecLs on an early difï"erentiation marker. ALP activity. I-lowever. the effects of HZ02 have not been well elucidated in primary cultured human pulp cells ln th is study‘ we investigated whether HO- 1 is involved in H20 2-induced cytotoxicity and examined the production 0 1" dent in sia lophosphoprotein (DSPP) and other minera li zation markers, in human pulp cells H20Z dec1'eased cell viabili ty. but increased HO-l and DSPP expression in a concentra t ion and time dependent manner. Inhibitors of guanylate cyclase, PI3K. ERK, and p38 MAP kinase blocked J-!?,0 2- induced cytot oxicity and the expression of HO-1 and DSPP mRNAs in pulp cells. These data suggest that t he induction of HO-l by H202 in pu lp cells plays a protective role against the cytotoxic effects of H202 and stimulates DSPP expression. resulting in prematu re oclontoblast differentiation th rough pathways t hat involve cGMP. p38. ancl ERK

Although substance P (SP). a potent pro-inflammatory peptide, is involved in inflammation and immune responses, the effect of SP 011 the expression of macl'ophage inJlammatol'Y protein 3a (MIP-3a. CCL20) in periodontal ligament (PDL) cells a l'e unknown Equally as enigmatic is the link between SP. the stress protein heme oxygenase-l (HO-l) , and CCL20 product ion. We investigated whether SP induces the release of chemokine CCL20 from irrunortalized POL (IPDL) cells. and further claif’y SP mediated pathways . We also exarnined the relationship between HO-l and CCL20 by treating POL cells with SP Incubating IPOL cells with SP incl'eased ex pl'ession of CCL20 mRNA and CCL20 protein in a dose-time dependent manner. Highly selective p38 and ERKl/2 inhibitors abl'ogated SP-induced expression of CCL20 lD IPOL cells SP is also responsible fo l' ini tiating phosphorylation of I/( B‘ degl'adation of IK B. and activation of NF-/( B. SP induced expression of HO-l in both a concentration- and time-dependent manner. and CCL20 refl ected similal' patterns. The inductive effects of SP on HO-l and CCL20 were enhanced by HO- l inducer hemin and the membrane-permea ble cGMP analog 8-bromo-cGMP Conversely, this pathway was inhi bited by the HO-l inhibitor zinc Pl'otoporphyrin IX (ZnPP IX) and the selective inhibitor of guanylate cyclase‘ 1H- [1. 2. 4]uxad iazole[4, 3-alquinoxal i n- 1-one (ODQ) We report hel'ein the pathway that connects SP a long with other modulators 0 1' neuroimmunoregulationto the induction of HO-1 and the inflanunatol'y mediatol' MIP- 3a /CCL20 in IPDL cel ls. which play an impol'tant role in the development 0 1' pe- I'iodontitis or inflammation during ol'thodontic tooth movement