Usefulness of Preoperative Preparation in Using Gore-Tex / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Gore-Tex is a popular graft material used in rhinoplasty. But there are several complications such as infection, seroma, and persistent swelling. Infection is the most common complication. The aim of this study was the evaluation of various protocols for Gore-Tex decontamination. SUBJECTS AND METHOD: Gore-Tex specimens were sectioned and separated into six groups. These were treated with povidone-iodine or antibiotics solution. Nasal cavity swab was performed both in the control group and patient group of chronic sinusitis. The culture of swab specimens incubated in agar plates were compared statistically. RESULTS: Povidone-iodine groups revealed significant decrease in the bacterial colony counts. CONCLUSION: The results suggested that impregnation of povidone-iodine supports the efficacy of decontamination Gore-Tex Implant.

Two Cases of Meatoplasty and Otoplasty Simultaneously in Patients with Auricular Deformities and External Auricular Canal Stenosis / 대한이비인후과학회지

As the auricle is a very complex structure covered with thin, sensitive skin, the best reconstruction requires a great deal of skill and the use of diverse approaches. Otolaryngologists should give greater consideration to otoplasty because patients do not want their self-confidence impaired by auricular deformities. When treating external auditory canal (EAC) cholesteatoma caused by EAC stenosis, the blood circulation may be deleteriously affected if the retroauricular incision is made first, and thus the otoplasty must be first carried out. We report two cases of otoplasty performed simultaneously with meatoplasty without the aid of plastic surgeons. The first case involved a 33-year-old woman with cholesteatoma due to congenital auricular atresia and microtia. The second case was a 64-year-old man with traumatic auricular amputation and EAC stenosis due to scar contracture. Simultaneous otoplasty and meatoplasty should be of benefit to patients because it reduces the number of operations and has a high success rate.

A Case of Malignant Peripheral Nerve Sheath Tumor in Nasal Cavity / 대한이비인후과학회지

The malignant peripheral nerve sheath tumor (MPNST) is an extremely rare soft tissue sarcoma of ectomesenchyme. It is a highly malignant sarcoma, which is locally invasive, frequently leading to multiple recurrences and eventual metastatic spread. The peak incidence of this disease is known to arise in the seventh decades. In human body, trunk and extremities are the most commonly involved site, and only 8-14% of all lesions appears in head and neck region. Because of its non-specific clinical and histopathological presentation, the diagnosis of MPNST has been described as one of the most difficult diagnosis. But this difficulty of diagnosis was solved by the use of immunohistochemistry. The authors report a case of malignant peripheral nerve sheath tumor in nasal cavity with a review of the literature.

Clinical Study of Facial Skin Cancer / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Malignant skin cancer is the most common type of malignancy, and is frequently found and increasing nowadays. Surgery for removal of skin cancer is very important. The authors had good results from surgery and reconstruction of facial defect. The effective surgical method and variable method of reconstruction are described here with a clinical analysis. SUBJECTS AND METHOD: 19 patients who were diagnosed facial skin cancer were divided by age, sex, type of cancer, region, and reconstruction method, and they were analyzed retrospectively. RESULTS: Of the 19 patients, squamous cell carcinomas were 5, basal cell carcinomas 11, and Merkel cell carcinoma 2. One patient had basosquamous cell carcinoma. Sites of skin cancer occurrence was nasal region (11 patients), auricular region (4 patients), cheek (2 patients) and preauricle (2 patients). Reconstruction was done right after the excision. There was no recurrence cases to date. CONCLUSION: The authors had good results regarding reconstruction following the excision of the skin cancer. Therefore, every physician have to consider this method as a treatment of skin cancer, and think of as many reconstruction methods as possible for the patient.

In vitro study of tooth temperature change during polymerization reaction of the cold-cured resins used in provisional crown and fixed partial dentures / 대한치과보철학회지

STATEMENT OF THE PROBLEM: The cold-cured resins used in fabrication of the provisional crown and fixed partial dentures could cause pulpal damage by heat generated during exothermic polymerization reactions. PURPOSE: In this in vitro study investigates the how external conditions such as material of the matrix, thickness of the matrix and thickness of dentin affect the temperature of the tooth during polymerization reaction of the cold-cured resins. MATERIAL AND METHODS: To measure the temperature of the resin, metal die was maintained to the temperature of 37 degrees C with water bath to simulate the temperature of thetooth and thermocouple was placed in the center of the metal die. Acrylic pipe was cut in height of 1, 2, 3, 6, 10 mm and placed on the metal die and mixed resin was pored in the acrylic pipe. As the resin polymerized temperature was recorded with the thermometer. Temperature of the resin using matrix was recorded by using the individual tray relieved in different thickness 2, 5, 7, 10 mm. The material of the matrix was irreversible hydrocolloid impression material, vinyl polysilloxane impression material and vacuum-formed template. Temperature rise of the resin using different thickness of tooth section was recorded by placing tooth section on the metal die and placing resin over the tooth section. RESULTS: [Table]. CONCLUSION: 1. Temperature rise increased as the thickness of the resin increased but there was no significant differences over 3 mm thickness of the resin. 2. The lowest temperature rise was showed in irreversible hydrocolloid impression material and vinyl polysilloxane impression material, vacuum-formed template as in orders. 3. Temperature rise of the resin decreased regardless of the thickness of the matrix when vinyl polysilloxane impression material was used as the matrix. 4. When irreversible hydrocolloid impressionmaterial was used as matrix, the temperature rise of the resin decreased as the thickness of the matrix increased and there was no temperature rise when thickness of the matrix reached 10 mm. 5. The temperature rise of the resin did not decreased when Polypropylene vacuum-formed template was used as the matrix. 6. The temperature of the resin increased as the thickness of the dentin decreased.

Finite element analysis on maxillary molar implant under different C/R ratio / 대한치과보철학회지

STATEMENT OF THE PROBLEM: In cases of low bone level in maxilla followed by extraction due to severe periodontitis or enlarged maxillary sinus, crown-root ratio of implant prosthesis will increase. The prognosis of these cases is not good as expected. PURPOSE: The purpose is to compare stress distribution due to crown-root ratio and effect of splinting between two implants in maxillary molar area under different loads MATERIAL AND METHODS: Using ITI(4.1 x 10 mm) implant, two finite element models were made(model S: two parallel implants, model A: one of two is 20 degree inclined). Each model was designed in different crown-root ratio(0.7:1, 1:1, 1.25:1) and set cement type gold crown to make it splinted or non-splinted clinical situations. After that, 300 N force was loaded to each model in four ways.(load 1 : middle of occlusal table, load 2 : middle of buccal cusp, load 3 : middle of lingual cusp, load 4 : horizontal load to middle of buccal cusp), and stress distribution was analyzed. RESULTS: On all occasions, stress was concentrated on neck of implant near cortical bone. In the case of inclined implant, stress was increased compared with parallel implants. Under load 1, 2, 3, stress was not increased even when crown-root ratio increases, but under load 4, when crown-root ratio increases, stress also increased. And more stress was concentrated under load 1 than load 2, 3. When crown-root ratio was same, stress under load 1, 2, 3 decreased when splinting, but under load 4, stress did not really decrease. CONCLUSION: Under vertical load, stress distribution related to crown-root ratio did not change. But under horizontal load, stress increased as crown-root ratio increases. Under vertical load, splinting decreased stress but under horizontal load, effect of splinting was decreased as condition of implant changes for the worse such as increase of crown-root ratio, inclined implant.