• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.3123-3129
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• 2013

Background: The search for naturally occurring agents in routinely consumed foods that may inhibit cancer development is of high priority. [6]-Paradol is a pungent phenolic bioactive component from ginger with welldocumented health promoting antioxidant, antimutagenic, antigenotoxic and anti-inflammatory properties. However, anticarcinogenic effects have yet to be fully explored. The objectives of the present study were therefore to assess protective effects against 7,12-dimethylbenz(a)anthracene (DMBA) induced buccal pouch carcinogenesis in male golden Syrian hamsters. Methods: Oral squamous cell carcinomas developed in the left buccal pouch of hamsters on painting with 0.5% of DMBA, three times in a week. To assess the apoptotic associated gene expressing potential of [6]-paradol, it was orally administered to DMBA treated hamsters on alternate days from DMBA painting for 14 weeks. Results: We observed 100% tumor formation with marked levels of neoplastic changes and altered the expression of apoptotic associated gene (p53, bcl-2, caspase-3 and TNF-${\alpha}$) was observed in the DMBA alone painted hamsters as compared to control hamsters. Oral administration of [6]-paradol at a dose of 30 mg/kg b.wt to DMBA treated animals on alternative days for 14 weeks significantly reduced the neoplastic changes and improved the status of apoptosis associated gene expression. Conclusion: These observations confirmed that [6]-paradol acts as a tumor suppressing agent against DMBA induced oral carcinogenesis. We also conclude that [6]-paradol also effectively enhances apoptosis- associated gene expression in DMBA treated animals.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.2
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• pp.66-73
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• 2015

Objectives: To assess the validity of the vertical tube-shift method using intraoral periapical radiography (IOPAR) for determining the relationship between the mandibular third molar roots and the inferior alveolar nerve (IAN) canal in comparison with cone-beam computed tomography (CBCT). Materials and Methods: Fifty impacted mandibular third molars were analyzed using the IOPAR vertical tube-shift method and CBCT. The relationship of the IAN canal to the impacted mandibular third molar was recorded as buccal, lingual or in line with the apex and was compared with CBCT findings. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the vertical tube-shift method in depicting the relationship (buccal/lingual/in line with the apex) of the IAN canal to the third molar root apex was calculated. Results: The sensitivity and specificity PPV and NPV of the IOPAR vertical tube-shift technique was found to be highest for a lingual relationship (100%) followed by buccal (94.4%, 92.3%, 97.1%, and 85.7%) and in line with the apex relationship (88.9%, 95.0%, 80.0%, and 97.4%) of the IAN canal with the third molar root apex, respectively. A statistically significant association was observed between the IOPAR vertical tube-shift method and the CBCT with a P-value <0.01. Conclusion: The vertical tube-shift method can be used as an effective diagnostic tool in assessing the relationship of the IAN canal to the third molar root apex with high sensitivity, specificity, PPV, and NPV.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.44-56
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• 1990

This study was designed to assess the degree of the marginal leakage of posterior composite restorations with glass ionomer cement base and Scotchbond$^{(R)}$ by means of the dye penetration at the enamel and dentinal margins. 160 cavities of class V were prepared on the buccal and lingual surfaces of 80 extracted premolar and molar teeth, which were divided into two groups. The buccal cavities of one group were filled with GC lining cement$^{(R)}$, Scotchbond$^{(R)}$ and P 50$^{(R)}$ and the lingual cavities were filled with Scotchbond$^{(R)}$ and Heliomolar$^{(R)}$. The Buccal cavities of other group were filled with Logobond$^{(R)}$, Scotchbond$^{(R)}$ and Heliomolar$^{(R)}$ and lingual cavities were filled with Scotchbond$^{(R)}$ and P 50$^{(R)}$. After finishing, all specimens were subjected manually to 50 thermal cycles at $4^{\circ}C$ and $60^{\circ}C$. They were immersed in 0.5% methylene blue solution for 24 hours and buccolingually sectioned with diamond disc. The sectioned specimens were examined under light microscope. The following results were obtained. 1. The group filled with glass ionomer cement base showed less marginal leakage than the group filled without glass ionomer cement base. 2. The enamel margins showed less microleakage than the dentinal margins in both of the two groups. 3. No significant difference was showed in the microleakage, irrespective of two glass ionomer cement base and posterior composite resin.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.1
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• pp.17-24
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• 2016

Background: To evaluate the antimicrobial activity of lidocaine (LD) topical anesthetic spray against oral microflora. Methods: Antimicrobial effects of 10% LD spray were assessed against six bacterial cultures obtained from volunteers: Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, Streptococcus salivarius, Streptococcus pyogenes, and Streptococcus sanguinis. The filter papers contained $50-{\mu}l$ LD, brain heart infusion (BHI) broth, or 0.2% chlorhexidine. Papers were placed on the cultured blood plates for 1-3 min. After the papers were removed, plates were incubated for 24 h. Bacterial growth on the contact areas was recorded as the antimicrobial score. The split mouth technique was use in for sample collection in clinical study. Filter papers soaked with either BHI broth or LD were placed on the right or left buccal mucosa for 1 min, and replaced with other papers to imprint biofilms onto the contact areas. Papers were placed on blood plates, incubated for 24 h, and antimicrobial scores were determined. Experiments were conducted for 2- and 3-min exposure times with a 1-day washout period. Results: LD exhibited bactericidal effects against E. coli, S. sanguinis, and S. salivarius within 1 min but displayed no effect against S. aureus, E. faecalis, and S. pyogenes. The antimicrobial effect of LD on oral microflora depended upon exposure time, similar to the results obtained from the clinical study (P < 0.05). LD showed 60-95% biofilm reduction on buccal mucosa. Conclusions: Antimicrobial activity of 10% LD topical anesthetic spray was increased by exposure time. The 3 min application reduced oral microflora in the buccal mucosa.

• Imaging Science in Dentistry
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• v.46 no.2
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• pp.117-125
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• 2016

Purpose: This study evaluated and compared interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns, using cone-beam computed tomography (CBCT). Materials and Methods: Pretreatment CBCT images of 24 Thai orthodontic patients with Class I and Class II skeletal patterns were included in the study. Three measurements were chosen for investigation: the mesiodistal distance between the roots, the width of the buccolingual alveolar process, and buccal cortical bone thickness. All distances were recorded at five different levels from the cementoenamel junction (CEJ). Descriptive statistical analysis and t-tests were performed, with the significance level for all tests set at p<0.05. Results: Patients with a Class II skeletal pattern showed significantly greater maxillary mesiodistal distances (between the first and second premolars) and widths of the buccolingual alveolar process (between the first and second molars) than Class I skeletal pattern patients at 10 mm above the CEJ. The maxillary buccal cortical bone thicknesses between the second premolar and first molar at 8 mm above the CEJ in Class II patients were likewise significantly greater than in Class I patients. Patients with a Class I skeletal pattern showed significantly wider mandibular buccolingual alveolar processes than did Class II patients (between the first and second molars) at 4, 6, and 8 mm below the CEJ. Conclusion: In both the maxilla and mandible, the mesiodistal distances, the width of the buccolingual alveolar process, and buccal cortical bone thickness tended to increase from the CEJ to the apex in both Class I and Class II skeletal patterns.

• Imaging Science in Dentistry
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• v.42 no.4
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• pp.219-224
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• 2012

Purpose: This study investigated the relationship between the roots of the maxillary molars and the maxillary sinus using cone beam computed tomography (CBCT), and measured the distances between the roots of the maxillary molars and the sinus floor as well as the thickness of the bone between the root and the alveolar cortical plate. Materials and Methods: The study sample consisted of 83 patients with normally erupted bilateral maxillary first and second molars. A total of 332 maxillary molars were examined using CBCT images. The vertical relationship of each root with the maxillary sinus was classified into four types on CBCT cross-sectional images. The distance between the sinus floor and root and the bone thickness between the root and alveolar cortical plate were measured. Results: In the buccal roots of the maxillary molars, a root protruding into the sinus occurred most frequently. A root projecting laterally along the sinus cavity was most common in the palatal roots of the maxillary first molars. The mesiobuccal roots of the maxillary second molar were closest to the sinus. The mesiobuccal roots of the first molars were closest to the cortical plate. Conclusion: The relationship between the roots of the maxillary molars and the sinus differed between the buccal and palatal roots. A root protruding into the sinus occurred more frequent in the buccal roots of the maxillary molars. The mesiobuccal root of the maxillary second molar was closest to the maxillary sinus floor and farthest from the alveolar cortical plate.

• Imaging Science in Dentistry
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• v.39 no.2
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• pp.81-87
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• 2009

Purpose: To evaluate the anteroposterior length and buccal angle of the anterior loop, and the size and location of the mental foramen using cone beam computed tomography (CBCT). Materials and Methods: 100 CBCT images from 87 adults (43 males and 44 females) ranging in age from 20 to 73 years (average 50 years) with edentulous ridge of the mandibular premolar region were obtained. Axial, sagittal, coronal images were reconstructed from Dental and Block Images of CBCT. The anteroposterior length, shape and buccal angle of the anterior loop, and the size and location of the mental foramen were calculated from reconstructed images of axial, sagittal and coronal CBCT. Results: The anteroposterior length and buccal angle of the mental canal was 4.0${\pm}$1.2mm, 37.8${\pm}$11.60$^{\circ}$respectively. The loop type with straight course was the most common shape of the mental canal. The location of the mental foramen below the apex of the lower second premolar (78%) was the most common. The maximum size of the mental foramen was 4.6${\pm}$1.0 mm in width and 3.0${\pm}$0.6 mm in height. The inner size of the mental canal was 2.6${\pm}$0.6 mm in width and 2.1 mm${\pm}$0.4 mm in height. Conclusion: CBCT is useful to evaluate the anterior loop and mental foramen of the mandibular canal. Safe guideline of 4 mm from the most anterior point of the mental foramen is recommended for implant and surgical treatment. (Korean J Oral Maxillofac Radiol 2009; 39: 81-7)

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.4
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• pp.818-839
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• 1996

The strain gage, holographic and photoelastic analysis etc. have been used for stress analysis of prosthesis, orthodontic or orthopedic appliances and filling materials. But these methods has some limitation in analyzing the internal stress. The Finite Element Analysis has been proved to compensate this defect and widely used in this area. The purpose of this study was to compare the stress distributions of the various temporary filling methods being used in pulpotomy procedure. Three different models were designed according to temporary filling material and method: amalgam filling with ZOE base(Model I), amalgam filling with ZPC sub-base and ZOE(Model II), IRM filling only(Model III). The results of the experiment were as follows: 1. In model I under the load case 6 and 1, the significant stress was shown to be concentrated on the buccal portion of crown. 2. Model II showed the similar pattern of stress distribution to Model I. 3. In model III under load case 2, the stress was mainly distributed on the buccal cusp tip and buccal margin of filling material. In same model under the load case 3, the stress was distributed on the lingual cusp tip. 4. Based on the above data, IRM can be assumed to have advantage over the other tested materials in reducing the incidence of crown fracture by localized the stress within the filling materials.

• Archives of Craniofacial Surgery
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• v.21 no.3
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• pp.161-165
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• 2020

Background: Microstomia is defined as a condition with a small sized-mouth that results in functional impairment such as difficulty with food intake, pronunciation, and poor oral hygiene and cosmetic problems. Several treatment methods for microstomia have been proposed. None of them are universally applicable. This study aims at analyzing the cases treated at our institution critically reviewing the pertinent literature. Methods: The medical records of all microstomia patients treated in our hospital from November 2015 to April 2018 were reviewed retrospectively. Of these, all patients who received surgical treatment for microstomia were included in the study and analyzed for etiology, chief complaint, surgical method, and outcomes. The functional outcomes of mouth opening and intercommissure distance before and after the surgery were evaluated. The cosmetic results were assessed according to the patients' satisfaction. Results: Five patients with microstomia were corrected. Two cases were due to scar contracture after chemical burn, two cases derived from repeated excision of skin cancer, and one patient suffered sequela of Stevens-Johnson syndrome. The following surgical methods were applied: one full-thickness skin graft on the buccal mucosa, three buccal mucosal advancement flaps after triangular excision of the mouth corner, and one local buccal mucosal flap. Mouth opening was increased by 6.0 mm, and the intercommissure distance improved by 7.2 mm on average. Follow-up was 9.6 months (range, 5-14 months). Cosmetic assessment was as follows: two patients found the results excellent, three judged it as good. Conclusion: Microstomia has several causes. In order to achieve optimal functional recovery and aesthetic improvement it is important to precisely evaluate the etiologic factors and the severity of the impairment and to carefully choose the appropriate surgical method.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.2
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• pp.185-199
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• 1999

This study was peformed to investigate the distribution and magnitude of stress at supporting tissue of abutment teeth and residual ridge tissue with remaining unilateral posterior teeth. Four types of removable partial dentures that included clasp retained removable partial denture, attachment retained removable partial denture, telescopic removable partial denture, and swing-lock partial denture were designed, and strain gauge was used for stress analysis. Each prosthesis was subjected to simulated vertical and oblique load. The following conclusions were drawn from this study. 1. The clasp retained removable partial denture generally distributed simulated vertical force more evenly to the supporting structure. 2. The stress at buccal side of 1st premolar was the lowest in swing-lock partial denture and that was highest in attchment retained removable partial denture. The stress at lingual side of 1st premolar was the lowest in telescopic partial denture. 3. In clasp retained removable partial denture, stress was lower at load site and ridge crest at mid-line, but it was higher at 1st premolar area on vertical load. 4. In attachment removable partial denture, stresses at buccal side of 1st premolar. lingual side of 1st premolar on vertical load, and ridge crest at midline on oblique load were higher. 5. In telescopic removable partial denture, stress at lingual side of 1st premolar was the least in all removable partial dentures, but the stress at load site was higher. 6. In swing-lock removable partial denture, stress at buccal side of 1st premolar was the lowest, and stresses at load site and distal end of residual ridge crest were higher.