Background: Epidermoid cysts are benign tumors derived from the infundibular portion of hair follicles and thus have a flattened surface epithelium and keratohyaline granules. They can occur at any age but are most frequently reported in adults, and more often occur in men than women. Most epidermoid cyst operations are performed for cosmetic purposes, or to relieve inflammation. The definitive treatment is complete excision or destruction of the cyst. The aim of this study was to improve understanding of epidermoid cysts. Methods: We analyzed 432 cases of epidermoid cyst in 398 patients that underwent complete excision and biopsy between April 2001 and March 2020, according to patient age, patient gender, and lesion location. Results: From all epidermoid cyst excisions performed, 17.6% were for patients in their 40s and 50s, 16.8% for those in their 20s, 16.1% for those in their 30s, 14.6% for those aged 60 or older, 5.0% for teenagers, and 0.5% for those under 10 years. Cases of epidermoid cysts occurred at a men-to-women ratio of about 3:2, with 59.5% of cases in men and 40.5% in women. By lesion location, 65.0% of cases were on the face, 10.9% on the trunk, 7.9% on the scalp, 7.9% on the neck, 4.3% on lower extremities, 3.9% on upper extremities, and 0.2% on genitalia. On the face, 20.8% of cases were on the cheek, 12.7% on the periauricular area, 10.9% on the periorbital area, 6.0% on the frontal area, 5.6% on the mental area, 3.7% on the perioral area, 2.8% on the nasal area, and 2.5% on the temporal area. Conclusion The proportion of women with epidermoid cysts was higher in our study than in previous studies. Moreover, the results showed that surgery has been on the rise in recent years, with facial surgery being the most common.

Mucosa-associated lymphoid tissue (MALT) lymphoma is an uncommon form of non-Hodgkin lymphoma involving the mucosa-associated lymphoid tissue. Most commonly affected organ is the stomach. But, it could affect almost every organ in the whole body. If they have suspicious lesion, excision biopsy could be made. For staging, blood test including blood smear, abdomen and chest tomography or scan will be checked. Also, bone marrow test can be done if it is needed. The patient had visited the clinic for palpable mass on right lower eyelid. With excisional biopsy, it was diagnosed as lymphoid hyperplasia on pathologic test. But 2 years later, the patient came with recurrent symptom for our department with worry. At that time, we recommended excisional soft tissue biopsy under general anesthesia. Unfortunately, it was revealed MALT lymphoma on pathologic finding. It turned out to be stage 3 in Ann Arbor staging system without B symptoms. Hematologic consultation was made and she was treated with adjuvant chemotherapy for eight cycles to complete remission. We report a case of MALT lymphoma on subcutaneous tissue at right lower eyelid previously diagnosed as lymphoid hyperplasia.
Abdomen ; Anesthesia, General ; Biopsy ; Bone Marrow ; Chemotherapy, Adjuvant ; Eyelids ; Hematologic Tests ; Humans ; Hyperplasia ; Lymphoid Tissue ; Lymphoma ; Lymphoma, B-Cell, Marginal Zone ; Lymphoma, Non-Hodgkin ; Stomach ; Subcutaneous Tissue ; Thorax

BACKGROUND: Topical hemostatic agents are used when ligation, electrocauterization, or other conventional hemostatic methods are impractical. Because a hemostatic agent is a foreign body, it can cause foreign body reactions, inflammation, and infections that can interfere with the wound healing process. Therefore, we should select hemostatic agents after considering their effects on wound healing. Here, we compared the effects of hemostatic agents on wound healing in a rectus abdominis muscle defect in rats. METHODS: Twelve Sprague Dawley rats were subjected to creation of a 6 × 6 mm defect in the rectus abdominis muscle and divided into four groups: control group; group A, Tachosil fibrin sealant patch; group B, Surgicel Fibrillar oxidized regenerated cellulose; and group C, Surgicel Snow oxidized regenerated cellulose. For the histologic analysis, biopsies were performed on the 3rd, 7th, and 27th days. RESULTS: The foreign body reaction was the weakest in group A and most significant in group C. The inflammatory cell infiltration was the weakest in group A and similar in groups B and C. Muscle regeneration differed among periods. The rats in group A were the most active initially, while those in group C showed prolonged activity. CONCLUSION: Tachosil and Surgicel administration increased inflammation via foreign body reactions, but the overall wound healing process was not significantly affected. The increased inflammation in the Surgicel groups was due to a low pH. We recommend using Tachosil, because it results in less intense foreign body reactions than Surgicel and faster wound healing due to the fibrin action.
Animals ; Biopsy ; Cellulose ; Cellulose, Oxidized ; Fibrin Tissue Adhesive ; Fibrin ; Fibrinogen ; Foreign Bodies ; Foreign-Body Reaction ; Hemostatics ; Hydrogen-Ion Concentration ; Inflammation ; Ligation ; Rats ; Rats, Sprague-Dawley ; Rectus Abdominis ; Regeneration ; Snow ; Thrombin ; Wound Healing ; Wounds and Injuries

Malignant pilomatricoma (pilomatrical carcinoma) is a rare, locally occurring malignant tumor with a high rate of recurrence in the case of incomplete excision. This tumor has two characteristics. First, recurrences of pilomatrical carcinoma are common; second, distant metastasis is rare, but if it occurs, it is very fatal. It has characteristic features of high mitotic counts, cellular atypia, and local invasion. Although fine needle aspiration and excisional biopsy could help to confirm this tumor diagnosis, pathologic findings are critical. Pilomatricomas have some characteristic features in histological aspect, such as epithelial islands of basaloid cells and shadow cells or ghost cell. Also, various types of immunohistochemical staining are used to confirm the diagnosis. Despite the lack of clear surgical criteria, treatment is a wide local excision with histologically clear resection margins with or without adjuvant radiotherapy.
Biopsy ; Biopsy, Fine-Needle ; Cheek* ; Diagnosis ; Facial Neoplasms ; Humans ; Infant* ; Islands ; Neoplasm Metastasis ; Pilomatrixoma* ; Radiotherapy, Adjuvant ; Recurrence

PURPOSE: This study was performed to evaluate condylar surface changes and remodeling after orthognathic surgery using three-dimensional computed tomography (3D CT) imaging, including comparisons between the right and left sides and between the sexes. MATERIALS AND METHODS: Forty patients (20 males and 20 females) who underwent multi-detector CT examinations before and after surgery were selected. Three-dimensional images comprising thousands of points on the condylar surface were obtained before and after surgery. For the quantitative assessment of condylar surface changes, point-to-point (preoperative-to-postoperative) distances were calculated using D processing software. These point-to-point distances were converted to a color map. In order to evaluate the types of condylar remodeling, the condylar head was divided into six areas (anteromedial, anteromiddle, anterolateral, posteromedial, posteromiddle, and posterolateral areas) and each area was classified into three types of condylar remodeling (bone formation, no change, and bone resorption) based on the color map. Additionally, comparative analyses were performed between the right and left sides and according to sex. RESULTS: The mean of the average point-to-point distances on condylar surface was 0.11±0.03 mm. Bone resorption occurred more frequently than other types of condylar remodeling, especially in the lateral areas. However, bone formation in the anteromedial area was particularly prominent. No significant difference was found between the right and left condyles, but condylar surface changes in males were significantly larger than in females. CONCLUSION: This study revealed that condylar remodeling exhibited a tendency towards bone resorption, especially in the lateral areas. Condylar surface changes occurred, but were small.
Bone Remodeling ; Bone Resorption ; Female ; Head ; Humans ; Imaging, Three-Dimensional ; Male ; Mandibular Condyle ; Multidetector Computed Tomography ; Orthognathic Surgery* ; Osteogenesis

PURPOSE: The current study investigates the feasibility of a platform for a nationwide dose monitoring system for dental radiography. The essential elements for an unerring system are also assessed. MATERIALS AND METHODS: An intraoral radiographic machine with 14 X-ray generators and five sensors, 45 panoramic radiographic machines, and 23 cone-beam computed tomography (CBCT) models used in Korean dental clinics were surveyed to investigate the type of dose report. A main server for storing the dose data from each radiographic machine was prepared. The dose report transfer pathways from the radiographic machine to the main sever were constructed. An effective dose calculation method was created based on the machine specifications and the exposure parameters of three intraoral radiographic machines, five panoramic radiographic machines, and four CBCTs. A viewing system was developed for both dentists and patients to view the calculated effective dose. Each procedure and the main server were integrated into one system. RESULTS: The dose data from each type of radiographic machine was successfully transferred to the main server and converted into an effective dose. The effective dose stored in the main server is automatically connected to a viewing program for dentist and patient access. CONCLUSION: A patient radiation dose monitoring system is feasible for dental clinics. Future research in cooperation with clinicians, industry, and radiologists is needed to ensure format convertibility for an efficient dose monitoring system to monitor unexpected radiation dose.
Cone-Beam Computed Tomography ; Dental Clinics ; Dentists ; Humans ; Methods ; Radiation Dosage ; Radiation Monitoring ; Radiography ; Radiography, Dental*

PURPOSE: We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). MATERIALS AND METHODS: The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. RESULTS: VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05). CONCLUSION: It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method.
Absorbable Implants ; Absorption ; Image Processing, Computer-Assisted ; Osseointegration ; X-Ray Microtomography

PURPOSE: This study was performed to identify correlations between keratocystic odontogenic tumor (KCOT) data from CT sections, and data on the KCOT clinical manifestation and resulting dental expenses. MATERIALS AND METHODS: Following local Institutional Review Board (IRB) approval, a seven-years of retrospective study was performed regarding patients with KCOTs treated at the Seoul National University Dental Hospital. A total of 180 KCOT were included in this study. The following information was collected: age, gender, location and size of the lesion, radiological features, surgical treatment provided and dental expenses. RESULTS: There was no significant association between the size of the KCOT and age, gender, and presenting preoperative symptoms. In both jaws, it was unusual to find KCOTs under 10 mm. The correlation between the number of teeth removed and the size of the KCOT in the tooth bearing area was statistically significant in the mandible, whereas in the maxilla, no significant relationship was found. Dental expenses compared with the size of the KCOT were found to be significant in both jaws. CONCLUSION: The size of KCOT was associated with a significant increase in dental expenses for both jaws and the number of teeth removed from the mandible. These findings emphasize the importance of routine examinations and early detection of lesions, which in turn helps preserving anatomical structures and reducing dental expenses.
Cost of Illness ; Ethics Committees, Research ; Humans ; Jaw ; Mandible ; Maxilla ; Odontogenic Cysts ; Odontogenic Tumors ; Retrospective Studies ; Tooth ; Ursidae

PURPOSE: This study was performed to suggest reference line-pair values of panoramic images with clinically desirable qualities using an arch-form phantom stand. MATERIALS AND METHODS: The line-pair test phantom was chosen. A real skull model was selected for setting the arch-form model of the phantom stand. The phantom stand had slits in four regions (incisor, premolar, molar, TMJ). Four raw images of the test phantom in each region and one raw image of the real skull were converted into 50 test phantom images and 50 skull phantom images with various line-pair values. 50 post-processed real skull phantom images were divided into 4 groups and were randomly submitted to 14 evaluators. Image quality was graded on a 4 point scale (1. good, 2. normal, 3. poor but interpretable, and 4. not interpretable). The reference line pair was determined as the first line-pair value scored less than 2 points. RESULT: The mean scores tended to decrease as the line-pair values increased. The reference line-pair values were 3.19 LP/mm in the incisor, 2.32 LP/mm in the premolar and TMJ, and 1.88 LP/mm in the molar region. CONCLUSION: Image quality evaluation methods and criteria should be able to assess various regions considering the characteristics of panoramic systems. This study suggested overall and regional reference line-pair values and established a set of standard values for them.
Bicuspid ; Incisor ; Molar ; Phantoms, Imaging ; Radiography, Panoramic ; Skull ; Temporomandibular Joint

A ranula is a bluish, transparent, and thin-walled swelling in the floor of the mouth. They originate from the extravasation and subsequent accumulation of saliva from the sublingual gland. Ranulas are usually limited to the sublingual space but they sometimes extend to the submandibular space and parapharyngeal space, which is defined as a plunging ranula. A 21-year-old woman presented with a complaint of a large swelling in the left submandibular region. On contrast-enhanced CT images, it dissected across the midline, and extended to the parapharyngeal space posteriorly and to the submandibular space inferiorly. Several septa and a fluid-fluid level within the lesion were also demonstrated. We diagnosed this lesion as a ranula rather than cystic hygroma due to the location of its center and its sublingual tail sign. As plunging ranula and cystic hygroma are managed with different surgical approaches, it is important to differentiate them radiologically.
Contrast Media ; Female ; Floors and Floorcoverings ; Humans ; Lymphangioma, Cystic ; Mouth ; Mouth Floor ; Ranula ; Saliva ; Sublingual Gland ; Tomography, X-Ray Computed