Woong Nam

Effects of artemisinin and its derivatives on growth inhibition and apoptosis of oral cancer cells

Artemisinin is of special biological interest because of its outstanding antimalarial activity. Recently, it was reported that artemisinin has antitumor activity. Its derivatives, artesunate, arteether, and artemeter, also have antitumor activity against melanoma, breast, ovarian, prostate, CNS, and renal cancer cell lines. Recently, monomer, dimer, and trimer derivatives were synthesized from deoxoartemisinin, and the dimers and the trimers were found to have much more potent antitumor activity than the monomers.

Insulin-like growth factor II mRNA-binding protein 3: a novel prognostic biomarker for oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is caused by multiple factors, including carcinogen exposure. Insulin‐like growth factor II mRNA‐binding protein 3 (IMP3) is highly expressed in various cancer cells but is rarely expressed in normal cells. We investigated whether IMP3 can be used as a prognostic biomarker for OSCC.

Double continuous radial forearm flap for the reconstruction of full-thickness buccal cheek defect.

Figure 1 Intra-operative picture showing the anastomosed double RFFF. In the cases with a large buccal cheek cancer, a complete excision of the full-thickness buccal cheek is unavoidable. Hence, a subsequent reconstruction of the oral mucosa and facial skin is required. However, the reconstruction becomes complicated if it includes the oral commissure. Therefore, in many cases, the reconstruction has been performed by using folded, paddled flaps or a combination of two other forms of flaps, including a musculocutaneous flap and perforator flaps, such as the anterolateral thigh (ALT) flap. The radial forearm free flap (RFFF) is a highly suitable and most commonly used flap in comparison with other flaps such as the ALT, which are too bulky, for a buccal cheek reconstruction. Moreover, elevation of the forearm flap is easy, and blood supply is good. When using the RFFF, a single RFFF is used to fold a flap or make two separated skins to reconstruct the full-thickness buccal cheek defect. However, two long-pedicled large flaps are required if the size of the excised buccal cheek is large and there are no blood vessels to be used for microvascular anastomosis of the ipsilateral neck region due to radical neck dissection (RND). Hence, there are cases in which two RFFFs are needed. In such cases, a connection between the long-pedicled RFFF and the short-pedicled RFFF in the reconstruction is believed to be a good alternative to using each long-pedicled RFFF individually.

Complications in endoscopic-assisted open reduction and internal fixation of mandibular condyle fractures.

Endoscopic-assisted open reduction and internal fixation (EAORIF) of subcondylar fractures is minimally invasive, provides excellent visibility without a large incision, and reduces surgical scarring and the risk of facial nerve injury. This study evaluated the complications associated with EAORIF. Twenty-six patients underwent EAORIF for mandibular condyle fractures. The postoperative follow-up period was longer than 6 months. We analyzed associations between the complication incidence and the number of fixation plates, accompanying mandibular fractures, and age. Eighteen (69.2%) and 6 (23.1%) patients had temporary (<3 months after surgery) and long-term (>6 months after surgery) complications, respectively. Patients older than 30 years had complications more frequently than those younger than 30 years. Complication rates were similar for different numbers of fixation plates and among patients with and without accompanying mandibular fractures. EAORIF is a reliable technique for treating condylar fractures, regardless of patient age, number of fixation plates, or accompanying mandibular fractures. However, improvements are needed to reduce long-term complications.

Intraosseous nerve sheath tumors in the jaws

Although the head and neck region is recognized as the most common location for peripheral nerve sheath tumors, central involvement, particularly in the jaw bones, is quite unusual. Neurofibroma is one of the most common nerve sheath tumors occurring in the soft tissue and generally appears in neurofibromatosis 1 (NF1 or von Recklinghausens disease). Malignant peripheral nerve sheath tumors (MPNSTs) are uncommon sarcomas that almost always arise in the soft tissue. Here, we report four cases of intraosseous peripheral nerve sheath tumors occurring in the jaw bones and compare the clinical, radiologic, and pathologic findings in order to make a differential diagnosis.

Clear cell odontogenic carcinoma mimicking a cystic lesion: a case of misdiagnosis

Clear cell odontogenic carcinoma (CCOC) is a rare jaw tumor that was classified as a malignant tumor of odontogenic origin in 2005 by the World Health Organization because of its aggressive and destructive growth capacity and metastasis to the lungs and lymph nodes. We report a case of a 66-year-old female who had swelling, incision and drainage history and a well-defined unicystic radiolucent lesion that was comparable to a cystic lesion. At first, the patient received decompression, and the lesion size decreased. Three months after decompression, cyst enucleation was performed. The pathologic result indicated that the lesion was CCOC. In this report we emphasize that patients with painful cystic lesions in addition to jaw enlargement and loosening teeth should be considered for the possibility of malignancy.

Comparison of miniplates and biodegradable plates in reconstruction of the mandible with a fibular free flap.

Miniplates and reconstruction plates are usually used to fix a fibular free flap, the gold standard in reconstruction of large segmental mandibular defects. Though biodegradable plates are used in orthognathic operations and repair of fractures nowadays, we know of no studies of the use of biodegradable plates in the reconstruction of segmental mandibular defects including a fibular free flap. We retrospectively reviewed 47 patients who had reconstruction of segmental mandibular defects with fibular free flaps during the past 10 years, and recorded clinical data and morbidity. We compared patients who had reconstruction of such defects with fibular free flaps and miniplates (n=26) with those in whom biodegradable plates had been used (n=21). There was no significant difference between miniplates and biodegradable plates with regard to overall complications (p=0.45) and failure of flaps (p=0.59). After confounding factors had been adjusted for with Coxs proportional hazards regression, there was no significant difference in the proportion of patients who developed a complication between the two groups (p=0.4). The type of plate does not seem to affect overall morbidity in reconstruction of the mandible with a fibular free flap.

Mandibular Reconstruction with Vascularized Osseous Free Flaps: a Review of the Literature

PURPOSE This article reviews a few of the commonly used types of vascularized osseous free flaps in maxillofacial reconstruction, which still represents the gold standard of restoration. We also discuss the developing concepts in maxillofacial reconstruction. RECENT FINDINGS Most of the literature reconfirms the established patterns of reconstruction with the aid of vascularized osseous free flaps. This method of free-tissue transfer is also feasible in cases of osteoradionecrosis or bisphosphonate-related osteonecrosis of the jaw. These flaps are also suitable for prosthetic restoration using osseointegrated dental implants. SUMMARY Vascularized osseous free flaps still remain the standard of care. Improvements upon the free-tissue transfer method employing vascularized osseous free flaps, such as distraction osteogenesis, tissue engineering, and imaging techniques, currently require further development, but these technologies could lead to improved outcomes of maxillofacial reconstruction in the near future.

A method for detecting significant genomic regions associated with oral squamous cell carcinoma using aCGH

Array comparative genomic hybridization (aCGH) provides a genome-wide technique for identifying chromosomal aberrations in human diseases, including cancer. Chromosomal aberrations in cancers are defined as regions that contain an increased or decreased DNA copy number, relative to normal samples. The identification of genomic regions associated with systematic aberrations provides insights into initiation and progression of cancer, and improves diagnosis, prognosis, and therapy strategies. The McNemar test can be used to detect differentially expressed genes after discretization of gene expressions in a microarray experiment for the matched dataset. In this study, we propose a method to detect significantly altered DNA regions, shifted McNemar test, which is based on the standard McNemar test and takes into account changes in copy number variations and the region size throughout the whole genome. In addition, this novel method can be used to detect genomic regions associated with the progress of oral squamous cell carcinoma (OSCC). The performance of the proposed method was evaluated based on the homogeneity within the selected regions and the classification accuracies of the selected regions. This method might be useful for identifying new candidate genes that neighbor known genes based on the whole-genomic variation because it detects significant chromosomal regions, not independent probes.

Reconstruction of Combined Oral Mucosa-Mandibular Defects Using the Vascularized Myoosseous Iliac Crest Free Flap

The authors present five cases of combined oral mucosa-mandible defects reconstructed with the vascularized internal oblique-iliac crest myoosseous free flap. This technique has many advantages compared to other conventional methods such as the radial flap, scapula flap, and fibula flap. Vascularized iliac crest flaps provide sufficient high-quality bone suitable for reconstructing segmental mandibular defects. Although fibular flaps allow longer donor bone tissue to be harvested, the iliac crest can provide an esthetic shape for mandibular body reconstruction and also provides sufficient bone height for dental implants. Conventional vascularized iliac crest myoosseous flaps have excessive soft tissue bulk for reconstruction of intraoral soft tissue defects. The modification discussed in the present article can reduce soft tissue volume, resulting in better functional reconstruction of the oral mucosa. Another advantage is that complete replacement of the oral mucosa is observed in as early as one month post-operation. The final mucosal texture is much better than that obtained with other skin paddle flaps, which is especially beneficial for the placement of dental implant prostheses. Donor site morbidity looks to be similar to, if not less than that observed for other modalities in terms of function and esthetics. For combined oral mucosa-mandible defects, the vascularized internal oblique-iliac crest myoosseous free flap shows good results with respect to hard and soft tissue reconstruction.