In the orthodontics process, intervention and sliding of an orthodontic bracket during the orthodontic process can arise large response of the labio-cheek soft tissue. Soft tissue damage and ulcers frequently happen at the early stage of orthodontic treatment. In the field of orthodontic medicine, qualitative analysis is always carried out through statistics of clinical cases, while quantitative explanation of bio-mechanical mechanism is lacking. For this purpose, finite element analysis of a three-dimensional labio-cheek-bracket-tooth model is conducted to quantify the bracket-induced mechanical response of the labio-cheek soft tissue, which involves complex coupling of contact nonlinearity, material nonlinearity and geometric nonlinearity. Firstly, based on the biological composition characteristics of labio-cheek, a second-order Ogden model is optimally selected to describe the adipose-like material of the labio-cheek soft tissue. Secondly, according to the characteristics of oral activity, a two-stage simulation model of bracket intervention and orthogonal sliding is established, and the key contact parameters are optimally set. Finally, the two-level analysis method of overall model and submodel is used to achieve efficient solution of high-precision strains in submodels based on the displacement boundary obtained from the overall model calculation. Calculation results with four typical tooth morphologies during orthodontic treatment show that: ① the maximum strain of soft tissue is distributed along the sharp edges of the bracket, consistent with the clinically observed profile of soft tissue deformation; ② the maximum strain of soft tissue is reduced as the teeth align, consistent with the clinical manifestation of common damage and ulcers at the beginning of orthodontic treatment and reduced patient discomfort at the end of treatment. The method in this paper can provide reference for relevant quantitative analysis studies in the field of orthodontic medical treatment at home and abroad, and further benefit to the product development analysis of new orthodontic devices.
Humans ; Periodontal Ligament/physiology* ; Orthodontic Wires ; Cheek ; Ulcer ; Tooth ; Finite Element Analysis

No abstract available.
Cheek ; Melanosis ; Neck

Merkel cell carcinoma (MCC) is a rare and highly aggressive neuroectodermal carcinoma arising from mechanoreceptor Merkel cells. Multiple MCCs are even rarer. We report a case of two independent MCCs simultaneously present in the cheek of a patient, which were effectively and esthetically treated using a cheek flap. Punch biopsy performed in a 60-year-old woman admitted with a chief complaint of two skin-colored hard nodules in her left cheek, accompanied by an itching sensation, was suggestive of MCC. Accordingly, we performed sentinel lymph node biopsy through the modified Blair incision under general anesthesia, in cooperation with the head and neck surgery department. The defect was covered with a cheek flap by slightly extending the existing incision following wide excision with a safety margin of 1 cm. This paper is significant in that it introduces an effective reconstruction technique that maintains function using a cheek flap for the management of this rare case. In addition, this paper is the first to classify multiple MCCs according to the time of onset. We believe that this paper presents an effective alternative reconstruction technique with sentinel node biopsy through the modified Blair incision.
Anesthesia, General ; Biopsy ; Carcinoma, Merkel Cell ; Cheek ; Female ; Head ; Humans ; Mechanoreceptors ; Merkel Cells ; Middle Aged ; Neck ; Neural Plate ; Pruritus ; Sensation ; Sentinel Lymph Node Biopsy ; Surgical Flaps

In branchial lymphoepithelial cyst (BLEC), which is also known as branchial cleft cyst, the remnants of a branchial arch develop into a cyst, causing swelling. The first case of BLEC in the parotid gland was reported by Hildebrant in 1895. Since then, BLEC in the parotid gland has continued to be reported, but in rare cases. A 45-year-old man presented to our hospital with a swelling of the left cheek of approximately 6 months’ duration. The patient underwent a superficial parotidectomy and was pathologically diagnosed with BLEC. Of note, this was the first case of non-human immunodeficiency virus (HIV)-related BLEC of the parotid gland in South Korea. BLEC is a benign condition, but its treatment depends on the presence of HIV infection. In HIV-negative patients, BLEC does not require a further work-up to evaluate metastasis. Our case report describes the diagnosis and treatment of BLEC in a patient without HIV.
Branchial Region ; Branchioma ; Cheek ; Diagnosis ; HIV ; HIV Infections ; Humans ; Korea ; Middle Aged ; Neoplasm Metastasis ; Parotid Gland ; Salivary Glands

BACKGROUND: Age-related changes in facial skin is a major concern in women. This study aimed to objectively evaluate normal skin elasticity and age-related differences in the faces of East Asian women. There are no standard values for data related to normal skin on East Asian women. METHODS: We studied 129 healthy East Asian women without a history of cosmetic procedures or surgeries. Skin elasticity was assessed at the cheek and lower eyelid points, which were assessed on both the right and left sides of the face. RESULTS: The age of the subjects showed significant negative correlations with the R2 and R7 parameters, which represent skin elasticity after deformation. CONCLUSION: We therefore concluded that the primary decrease in skin elasticity in East Asian women occurs in the midface region.
Asian Continental Ancestry Group ; Cheek ; Elasticity ; Eyelids ; Female ; Humans ; Rejuvenation ; Skin Aging ; Skin

Dysplastic nevus is common and affects about 10% of the northern European-descendent population. Studies over the past several decades have identified dysplastic nevi as a risk factor for malignant melanoma. Furthermore, in rare cases, they confirmed that dysplastic nevi have progressed to melanoma. Cases in which dysplastic nevi progressed to malignant melanoma in multiple studies are not uncommon. A 35-year-old woman presented with the major symptom of multiple itchy brown nodules (2.0 cm× 1.3 cm) in the left cheek that had first appeared 20 years earlier. Complete excision was performed at the first visit; subsequent biopsy confirmed that they were dysplastic nevi. They recurred three times over 3 years at the same site, all of which were histologically diagnosed as dysplastic nevi. Five years after the final excision, a brownish nodule developed in the left cheek, with others at the left temporal region, right retroauricular region, and left shoulder at the same time. These lesions were histologically diagnosed as malignant melanoma. We experienced a case of malignant melanoma that occurred at the same site after three recurrences of dysplastic nevi. Although rare, the possibility of malignant melanoma should be considered in follow-ups in cases involving repeatedly recurrent dysplastic nevi.
Adult ; Biopsy ; Cheek ; Dysplastic Nevus Syndrome ; Female ; Follow-Up Studies ; Humans ; Melanoma ; Recurrence ; Risk Factors ; Shoulder ; Temporal Lobe

Intraorbital infection shows a low incidence, but it might cause blindness or even death. This case is unusual in that its origin from a craniofacial bone fracture prior to infection of the maxillary sinus. A 33-year-old female patient was referred for right cheek swelling. When she visited the emergency room, we removed right cheek hematoma and bacterial examination was done. In the past, she had craniofacial bone surgical history due to a traffic accident 6 years ago. Next day, the swelling had remained with proptosis and pus was recognized in the conjunctiva. We planned an emergency operation and removed the pus which was already spread inside the orbit. And the evaluation for sinusitis was consulted to the otorhinolaryngology department simultaneously. There were Prevotella oralis and methicillin-resistant Staphylococcus epidermidis bacterial infection in the intraorbital and sinus respectively. Afterwards, the vigorous dressing was done for over a month with intravenous antibiotics. Though the intraorbital infection was resolved, blindness and extraocular movement limitation were inevitable. In conclusion, close follow up of the maxillary sinus in facial bone fracture patients is important and aggressive treatment is needed when an infection is diagnosed.
Accidents, Traffic ; Adult ; Anti-Bacterial Agents ; Bacterial Infections ; Bandages ; Blindness ; Cheek ; Conjunctiva ; Emergencies ; Emergency Service, Hospital ; Exophthalmos ; Eye Infections ; Facial Bones ; Female ; Follow-Up Studies ; Fractures, Bone ; Hematoma ; Humans ; Incidence ; Maxillary Sinus ; Methicillin Resistance ; Orbit ; Otolaryngology ; Prevotella ; Sinusitis ; Staphylococcus epidermidis ; Suppuration

OBJECTIVES: Endoscopic prelacrimal medial maxillectomy (EPMM) was previously reported to treat maxillary inverted papilloma. This study aimed to compare prelacrimal recess approach with the conventional Caldwell-Luc approach (CLA) to remove benign maxillary sinus tumors and to evaluate the usefulness of this approach based on our experience. METHODS: Ten patients who underwent EPMM at our hospital from January 2013 to December 2017 were reviewed. We also reviewed 30 patients who underwent benign maxillary sinus tumor resection via CLA during the same period. From medical records, postoperative pathological results, complications due to surgery, and recurrence rate were evaluated. RESULTS: There were eight inverted papilloma, one ameloblastoma, and one ossifying fibroma in the EPMM group. In the CLA group, all 30 cases were inverted papilloma. There were no cases of failure at gross total removal during surgery, and no recurrences were observed during follow-up in either groups. Mean follow-up period was 13.0 months in CLA group and 10.8 months in EPMM group. Regarding postoperative complications, 11 patients of the CLA group (37%) and three patients of the EPMM group (30%) had numbness around the cheek and upper lip area after surgery (P=0.715). In the CLA group, there were eight patients who had numbness lasting more than 3 months after surgery, and two patients had numbness for more than 1 year. However, facial numbness disappeared within 3 months in all patients in the EPMM group, in which epiphora was not observed. CONCLUSION: EPMM is the effective surgical approach for resecting benign maxillary sinus tumor compared with CLA. Although facial numbness was reported in EPMM, the duration of numbness was shorter than CLA.
Ameloblastoma ; Cheek ; Endoscopy ; Fibroma, Ossifying ; Follow-Up Studies ; Humans ; Hypesthesia ; Lacrimal Apparatus Diseases ; Lip ; Maxillary Sinus Neoplasms ; Maxillary Sinus ; Medical Records ; Papilloma, Inverted ; Postoperative Complications ; Recurrence

Odontoma is an asymptomatic slow-growing odontogenic tumor. It is usually found by chance in the maxilla or mandible on radiography, or when it deforms the adjacent teeth. It is commonly found in patients who are 30 years of age or younger. We report our encounter with an odontoma within a dentigerous cyst found incidentally in a 56-year-old man. He presented with abnormal fullness in the right infraorbital area of the cheek. During the evaluation of the mass, we incidentally detected the odontogenic tumor within a dentigerous cyst in the patient's maxilla. Under general anesthesia, complete surgical drainage of the infraorbital cystic mass was performed. Enucleation of the odontogenic tumor and a bone grafting from the iliac bone were also performed. The final diagnosis was odontoma. After 2 years of follow-up, there was no sign of recurrence of the tumor. In case of odontogenic tumors, even in old patients, it is important to suspect an odontoma. When odontoma accompanies a dentigerous cyst, surgical excisional biopsy should be performed to rule out malignancy. In case of a large bony defect after enucleation, autogenous bone grafting is essential for reconstruction.
Alveolar Bone Grafting ; Anesthesia, General ; Biopsy ; Bone Transplantation ; Cheek ; Dentigerous Cyst ; Diagnosis ; Drainage ; Follow-Up Studies ; Humans ; Mandible ; Maxilla ; Middle Aged ; Odontogenic Tumors ; Odontoma ; Radiography ; Recurrence ; Tooth

Pleomorphic adenoma is the most common benign tumor of the salivary gland. Pleomorphic adenoma occurs most commonly in the parotid gland but it may involve other salivary gland such as submandible or lingual. We report an ectopic pleomorphic adenoma in the subcutaneous layer of the face. A woman presented with a mass of the nasolabial fold. After excision of the mass, it was revealed as an pleomorphic adenoma pathologically. An ectopic pleomorphic adenoma which was located in the subcutaneous layer of the face is very rare in medical literature.
Adenoma ; Adenoma, Pleomorphic ; Cheek ; Female ; Humans ; Nasolabial Fold ; Parotid Gland ; Parotid Neoplasms ; Salivary Gland Neoplasms ; Salivary Glands ; Skin ; Subcutaneous Tissue