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

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

Lipoma is one of the most common benign tumors in the human body. However, they are uncommon in the oral cavity. Oral lipomas can occur on the cheeks, tongue, lips, gums and rarely on the floor of the mouth. Clinical symptoms are usually asymptomatic yellow masses. Sometimes the tumor grows and can have difficulty speaking and mastication. The treatment of lipoma is surgical excision, and recurrence is rare. We present a case of oral lipoma in an unusal location on the floor of mouth which is rare in the literature.
Cheek ; Gingiva ; Human Body ; Lip ; Lipoma ; Mastication ; Mouth Floor ; Mouth ; Recurrence ; Tongue

cheek pressures and suprahyoid and buccinator muscle activities at various head rotations and tilts, as independent variables. The data were subjected to one-way analysis of variance and post-hoc (linear contrast) testing. Tongue elevation pressures differed significantly when the head was flexed or extended compared to the neutral position (P<0.01). Suprahyoid muscle activity varied significantly when the head was rotated left or right compared to neutral, or tilted with the tongue elevated (P<0.01). Cheek pressure varied significantly when the head was rotated left or right compared to neutral, or tilted (P<0.01). Both tongue and cheek pressures increased significantly when the head was extended or rotated contralaterally compared to the neutral position. Suprahyoid muscle activity increased when the head was flexed or extended, or contralaterally or ipsilaterally rotated compared to the neutral position. Therefore, we suggest that head rotation or tilting could be used to vary oral pressure and muscle activity.]]>
Adult ; Cheek ; Female ; Head ; Humans ; Male ; Muscles ; Tongue

Salivary gland tumors usually appear in solitary mass in single salivary gland. The coexistence of tumors with different histological types occurring within a unilateral parotid gland is an extremely rare event. We experienced a case which two different types of malignant tumors developed at different time points in same gland; metachronous tumors. The second tumor was excised widely and reconstruction was performed by free tissue transfer. Sensory and motor nerve to the left cheek appeared to be intact, and circulation was adequate. This rare case was presented in this article.
Adenocarcinoma ; Cheek ; Neoplasms, Second Primary ; Parotid Gland ; Salivary Glands

Merkel cell carcinoma (MCC) is a relatively rare and aggressive cutaneous neuroendocrine malignancy. It is characterized by high rates of recurrence and metastasis, both to regional lymph nodes and to distant locations. Its characteristic clinical manifestation is a single, painless, hard, erythematous nodule on a sun-exposed area, particularly in older men. Surgical management of both the primary site and the sentinel lymph node is the standard of care. In this article, we describe the diagnosis and treatment of a case of MCC in the left cheek.
Carcinoma, Merkel Cell ; Cheek ; Diagnosis ; Head ; Humans ; Lymph Nodes ; Male ; Merkel Cells ; Neck ; Neoplasm Metastasis ; Recurrence ; Skin Neoplasms ; Standard of Care