Chun-Pin Chiang

Regenerative Endodontic Treatment for Necrotic Immature Permanent Teeth

This retrospective study included 23 necrotic immature permanent teeth treated for either short-term (treatment period <3 months) or long-term (treatment period >3 months) using conservative endodontic procedures with 2.5% NaOCl irrigations without instrumentation but with Ca(OH)(2) paste medication. For seven teeth treated short-term, the gutta-percha points were filled onto an artificial barrier of mineral trioxide aggregate (MTA). For 16 teeth treated long-term, the gutta-percha points, amalgam, or MTA were filled onto the Ca(OH)(2)-induced hard tissue barrier in the root canal. We found that all apical lesions showed complete regression in 3 to 21 (mean, 8) months after initial treatment. All necrotic immature permanent teeth achieved a nearly normal root development 10 to 29 (mean, 16) months after initial treatment. We conclude that immature permanent teeth with pulp necrosis and apical pathosis can still achieve continued root development after proper short-term or long-term regenerative endodontic treatment procedures.

Community-based multiple screening model†‡§¶

Multiple disease screening may have several advantages over single disease screening because of the economics of scale, with the high yield of detecting asymptomatic diseases, the identification of multiple diseases or risk factors simultaneously, the enhancement of the attendance rate, and the efficiency of follow‐up.

Community-based multiple screening model: design, implementation, and analysis of 42,387 participants.

Multiple disease screening may have several advantages over single disease screening because of the economics of scale, with the high yield of detecting asymptomatic diseases, the identification of multiple diseases or risk factors simultaneously, the enhancement of the attendance rate, and the efficiency of follow‐up.

Effective indicators for diagnosis of oral cancer using optical coherence tomography

A swept-source optical coherence tomography system is used to clinically scan oral precancer and cancer patients for statistically analyzing the effective indicators of diagnosis. Three indicators are considered, including the standard deviation (SD) of an A-mode scan signal profile, the exponential decay constant (alpha) of an A-mode-scan spatial-frequency spectrum, and the epithelium thickness (T) when the boundary between epithelium and lamina propria can still be identified. Generally, in abnormal mucosa, the standard deviation becomes larger, the decay constant of the spatial-frequency spectrum becomes smaller, and epithelium becomes thicker. The sensitivity and specificity of the three indicators are discussed based on universal and individual relative criteria. It is found that SD and alpha are good diagnosis indicators for moderate dysplasia and squamous cell carcinoma. On the other hand, T is a good diagnosis indicator for epithelia hyperplasia and moderate dysplasia.

Histone deacetylase 2 expression predicts poorer prognosis in oral cancer patients

Histone deacetylase 2 (HDAC2) has been implicated in the development and progression of several human tumors. We immunohistochemically examined the expression of HDAC2 protein in 20 cases of oral epithelial dysplasia (OED) and 93 cases of oral squamous cell carcinoma (OSCC). Positive HDAC2 nuclear staining was observed in 80 of the 93 (86.02%) cases of SCC and 11 of the 20 (55%) cases of ED. The labeling index (LI) for HDAC2 nuclear staining increased significantly from ED (25.8+/-26.5%) to SCCs (59.8+/-28.5%) (p<0.001). No significant correlation was found between the HDAC2 expression level and patients age, sex, oral habits in oral SCC patients. However, cancer with advanced stage, larger tumor size, or positive lymph node metastasis had higher level of HDAC2 protein expression. Kaplan-Meier curves showed oral SCC patients with high HDAC2 expression (LI>50%), advanced stage, larger tumor size, or positive lymph node metastasis had significantly shorter overall survival (p=0.0158, 0.0267, 0.0029 and 0.02514, respectively by log-rank test) than others. The results of this study show for the first time that overexpression of the HDAC protein is a frequent event in oral cancer and could be used as a prognostic factor in oral SCC.

Central Ossifying Fibroma: A Clinicopathologic Study of 28 Cases

BACKGROUND/PURPOSE Central ossifying fibroma (COF) is the most common benign fibro-osseous lesion of the jaw. This retrospective study evaluated the clinical and histopathologic features of 28 COFs in Taiwanese patients. METHODS Twenty-eight consecutive cases of COF were collected from 1988 to 2006. The clinical data and microscopic features of these cases were reviewed and analyzed. RESULTS The mean age of patients at the time of diagnosis was 34 years. There were six male and 22 female patients. Twenty-six (93%) cases were found in the mandible and two (7%) in the maxilla. The most common sites for COFs were the molar region (17 cases, 61%), followed by the premolar (8 cases, 28%), and incisor/canine (3 cases, 11%) regions. Bone swelling or expansion (96%, 26/27) was the most frequent clinical presentation. Six (21%) COFs presented as a radiolucent lesion, 17 (61%) as a mixed lesion, and five (18%) as a radio-opaque lesion. No recurrence of the lesion was found after surgical excision in this series. Microscopically, COFs showed trabeculae of woven bone (25 cases) and/or lamellar bone (5 cases) and/or spherules of cementoid (19 cases) in a cellular fibrous connective tissue stroma. The stromal component was highly cellular in 21 cases, moderately cellular in seven cases, prominently vascular in 11, and collagenous in six. CONCLUSION COFs occur more frequently in female patients and in those in the second to fourth decades of life. The most commonly affected site is the mandible, especially the molar region. The majority of COF lesions present as a well-defined, mixed lesion radiographically. Most COFs can be treated by conservative surgical excision without subsequent recurrence.

Diagnosis of oral cancer by light-induced autofluorescence spectroscopy using double excitation wavelengths

A cancer diagnostic algorithm, light-induced autofluorescence spectroscopy using double excitations wavelengths, was employed for distinguishing between cancerous and normal oral mucosa. For emission spectra at the shorter excitation wavelengths (280, 290, and 300 nm), the ratio between the area under 325-335 nm and the area under 465-475 nm was calculated. In the same way, for emission spectra at the longer excitation wavelengths (320, 330, and 340 nm), the ratio between the area under 375-385 nm and the area under 465-475 nm was calculated. Receiver operating characteristic curves were used to evaluate the performance of algorithms using single and the double (by combining shorter and longer) excitation wavelengths. The results showed that better performance, up to sensitivity 81.25%, specificity 93.75%, and positive predictive value 92.86%, could be achieved by using the double excitation wavelengths. The present study can be useful as a basis for further investigation on in vivo autofluorescence measurement and analysis using double excitation wavelength.

First Untoward Events and Reasons for Tooth Extraction after Nonsurgical Endodontic Treatment in Taiwan

In this study, 857 teeth having undergone nonsurgical root canal treatment (NSRCT) in Taiwan in 2000 were evaluated during a 5-year follow-up period for first untoward events and reasons for tooth extractions. First untoward events occurred in 83 (9.7%) teeth during this follow-up period, and nonsurgical retreatment was performed for 20 (24.1%), 4 (4.8%) received apical surgery, and 59 (71.1%) were extracted. By the end of this 5-year follow-up period a total of 64 (7.5%) teeth had been extracted. There were 65 reasons for tooth extraction given by the 56 performing dentists who responded to the extraction reason questionnaires; 6 (10.7%) were attributed to endodontically related diseases, 15 (26.8%) to periodontal diseases, 26 (46.4%) to large decay or unrestorable tooth, and 18 (32.1%) to tooth fracture. The conclusion was that 7.5% of the NSRCT teeth were extracted by the end of the 5-year follow-up period, and only 10.7% of these teeth were extracted as a result of endodontically related diseases.

Induction of Dental Pulp Fibroblast Matrix Metalloproteinase–1 and Tissue Inhibitor of Metalloproteinase–1 Gene Expression by Interleukin–1α and Tumor Necrosis Factor–α Through a Prostaglandin–Dependent Pathway

Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) are involved in the degradation of extracellular matrix in many inflammatory diseases. Little is known regarding the expression of these mediators in dental pulp fibroblasts. The effects of proinflammatory cytokines (interleukin (IL)-1alpha and tumor necrosis factor-alpha (TNF-alpha)) and prostaglandin E2 (PGE2) on pulp fibroblast MMP-1 and TIMP-1 gene expression were investigated. Northern hybridization showed that IL-1alpha and TNF-alpha induced significant MMP-1 gene expression, with only little effect on TIMP-1 gene. Exogenous PGE2, however, upregulated TIMP-1 mRNA synthesis but not MMP-1. Concomitant addition of IL-1alpha and PGE2 or TNF-alpha and PGE2 suppressed MMP-1 mRNA production, compared with the groups treated with IL-1alpha or TNF-alpha alone. In contrast, PGE2 enhanced the upregulatory effects of TIMP-1 mRNA by IL-1alpha or TNF-alpha. Furthermore, cytokine stimulation of MMP-1 and TIMP-1 gene expressions can be enhanced or blocked by indomethacin, respectively, and reversed by exogenous PGE2. These results suggested that cytokine-stimulated MMP-1 and TIMP-1 gene expression in dental pulp fibroblasts was mediated, at least in part, by a prostaglandin-dependent pathway. The differential regulation of IL-1alpha or TNF-alpha-induced MMP-1 and TIMP-1 mRNA synthesis, as well as the direct upregulation of TIMP-1 gene expression by PGE2, also implied that prostaglandin may serve as a protective mechanism from excessive tissue breakdown during pulpitis.

Successful treatment of advanced bisphosphonate-related osteonecrosis of the mandible with adjunctive teriparatide therapy.

The management of bisphosphonate‐related osteonecrosis of the jaws (BRONJ) is challenging and controversial. At present, there is no established medication treatment for the disease.