Background: Longitudinal melanonychia (LM) is a common clinical finding. Most cases of LM are benign, and a waitand-see approach is preferred in the management of this condition. Nevertheless, it is important for clinicians to distinguish subungual melanoma (SUM) from other benign LMs. Objective: To evaluate the demographic and clinicopathologic characteristics of LM in the Korean population and to identify the predictor of SUM against other benign conditions. Methods: This was a single-center retrospective cohort study including patients who underwent nail biopsy for LM from January 2000 to May 2019. To identify the predictor of SUM, receiver operating characteristic (ROC) analyses was performed. Results: A total of 68 cases of biopsy-proven LM were included in the analysis. Among the 68 cases, 8 were SUM. In univariable analysis, patients diagnosed with SUM were older (p=0.035) and had a longer disease duration (p=0.004).They also showed multicolor pigmentation of LM (p=0.022),a larger width of LM (p＜0.001), and associated nail plate dystrophy (p=0.010) than patients diagnosed with benign conditions. In multivariable logistic regression, width of LM showed statistical significance (odds ratio, 1.083; 95% confidence interval, 1.018∼1.153). ROC analysis suggested that an LM width ＞28% of the whole nail was the predictor of SUM (area under the curve=0.883; p＜0.001). Conclusion SUM has distinct demographic and clinical features. The width of LM can predict SUM against other benign LMs.

Cystic lesions on the jaws with expansion can invade the adjacent anatomical structure, infiltrate and expand the jaws, cause facial deformity, etc. There is great potential for pathologic fractures after cyst enucleation, and damage to the major structures like the nerve, artery. For these reasons, marsupialization and decompression are commonly used to reduce the cystic size. In 1947, Thomas first mentioned decompression that reduces the osmotic pressure in a cyst by making a hole in the cyst and insert a drain. In our cases, a large sized cystic lesion was treated with a specific device made from an orthodontic band and spinal needle. This device is easy and effective for applications and self irrigation.
Arteries ; Congenital Abnormalities ; Decompression ; Decompression, Surgical ; Fractures, Spontaneous ; Jaw ; Mandibular Diseases ; Needles ; Osmotic Pressure ; Radicular Cyst ; Treatment Outcome

Because sublingual region is well-vascularized and sublingual artery is passed throughout this region, it should be careful not to perforate lingual cortex when placing dental implant on mandible. A 83-years-old male complained severe sublingual hematoma, hemorrhage and dyspnea came our outpatient department. He had received dental implant placement in the same day. He needed hemostasis and airway control. If soft tissue of sublingual region and the artery are injured, it may result in life-threatening excessive hemorrhage. In dental implant surgery, especially mandible, we should recognize the accurate shape of mandible and anatomy of sublingual region. It is important to stop anticoagulant agent before surgery. When a patient has airway obstruction, the operator should manage airway quickly.
Airway Management ; Airway Obstruction ; Arteries ; Dental Implants ; Dyspnea ; Hematoma ; Hemorrhage ; Hemostasis ; Humans ; Male ; Mandible ; Mouth Floor ; Outpatients ; Porphyrins ; Tracheotomy

OBJECTIVES: We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 (137Cs) in Seoul. METHODS: Using information regarding the frequency and duration of passing via the 137Cs contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. RESULTS: Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. CONCLUSIONS: An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of 137Cs contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.
Epidemiologic Studies* ; Humans ; Korea* ; Radiation Exposure* ; Seoul*

OBJECTIVES: We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 (137Cs) in Seoul. METHODS: Using information regarding the frequency and duration of passing via the 137Cs contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. RESULTS: Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. CONCLUSIONS: An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of 137Cs contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.
Epidemiologic Studies* ; Humans ; Korea* ; Radiation Exposure* ; Seoul*

INTRODUCTION: In today's society, the rapid and appropriate care of the dental emergency patients is much more important. So, a retrospective study on the characteristics of emergency dental injuries and diseases will be very meaningful. MATERIALS AND METHODS: This retrospective clinical study was carried by reviewing the radiographic films and emergency chart of 11,493 patients who had visited the emergency room of Hallym Sacred heart Hospital and were treated in the Department of Oral and Maxillofacial Surgery from January 2006 to December 2010. RESULTS: The male to female ratio was 1.9:1. The highest monthly incidence was observed in May (10.4%) and June (8.9%) and the peak age distribution was the first decade (56.0%), followed by the second decade (16.0%). Trauma was the most common cause in dental emergency patients, followed in order by toothache, odontogenic infection, temporomandibular joint (TMJ) disorder and oral hemorrhage. Soft tissue injury was most prevalent in the trauma group, followed by tooth injury and facial bone fractures. In the tooth injury group, tooth fracture (56.7%) showed the highest incidence followed in order by tooth subluxation (18.2%), tooth concussion (16.9%), tooth avulsion (11.5%) and alveolar bone fractures (3.7%). In the facial bone fracture group, mandibular fractures (81.8%) showed the highest incidence followed in order by maxilla fractures (15.7%), nasal bone fractures (9.0%), zygomaticomaxillary complex fractures (5.4%), orbital bone fractures (2.5%). In mandibular bone fractures, the most common location was the symphysis (70.1%), followed in order by the mandibular angle (33.0%), mandibular condyle (22.8%) and mandibular body (13.6%). In the infection group, a submandibular space abscess (46.2%) was most common followed in order by a buccal space abscess (17.4%), canine space abscess (16.9%) and submental space abscess (12.3%). TMJ dislocation (89.3%) showed the highest incidence in the TMJ disorder group, followed by TMJ derangement (10.7%). In the other group, a range of specific symptoms due to post operation complications, trigeminal neuralgia, chemical burns and foreign body aspiration were reported. CONCLUSION: For the rapid and appropriate care of the dental emergency patients, well-organized system should be presented in oral and maxillofacial surgery. And it is possible under analysis of pattern and the variation of the dental emergency patients.
Abscess ; Age Distribution ; Burns, Chemical ; Dislocations ; Emergencies ; Facial Bones ; Female ; Foreign Bodies ; Fractures, Bone ; Heart ; Humans ; Incidence ; Male ; Mandibular Condyle ; Mandibular Fractures ; Maxilla ; Nasal Bone ; Oral Hemorrhage ; Orbit ; Retrospective Studies ; Soft Tissue Injuries ; Surgery, Oral ; Temporomandibular Joint ; Temporomandibular Joint Disorders ; Tooth ; Tooth Avulsion ; Tooth Fractures ; Tooth Injuries ; Toothache ; Trigeminal Neuralgia ; X-Ray Film