• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.35 no.2
• /
• pp.73-81
• /
• 2013

Purpose: Smad4 is a central mediator for transforming growth factor-${\beta}$/bone morphogenetic protein ($TGF-{\beta}/BMP$) signals, which are involved in regulating cranial neural crest cell formation, migration, proliferation, and fate determination. Accumulated evidences indicate that $TGF-{\beta}/BMP$ signaling plays key roles in the early tooth morphogenesis. However, their roles in the late tooth formation, such as cellular differentiation and matrix formation are not clearly understood. The objective of this study is to understand the roles of Smad4 in vivo during enamel and dentin formation through tissue-specific inactivation of Smad4. Methods: We generated and analyzed mice with dental epithelium-specific inactivation of the Smad4 gene (K14-Cre:$Smad4^{fl/fl}$) and dental mesenchyme-specific inactivation of Smad4 gene (Osr2Ires-Cre:$Smad4^{fl/fl}$). Results: In the tooth germs of K14-Cre:$Smad4^{fl/fl}$, ameloblast differentiation was not detectable in inner enamel epithelial cells, however, dentin-like structure was formed in dental mesenchymal cells. In the tooth germs of Osr2Ires-Cre:$Smad4^{fl/fl}$ mice, ameloblasts were normally differentiated from inner enamel epithelial cells. Interestingly, we found that bone-like structures, with cellular inclusion, were formed in the dentin region of Osr2Ires-Cre:$Smad4^{fl/fl}$ mice. Conclusion: Taken together, our study demonstrates that Smad4 plays a crucial role in regulating ameloblast and odontoblast differentiation, as well as in regulating epithelial-mesenchymal interactions during tooth development.

• Journal of Oral Medicine and Pain
• /
• v.17 no.2
• /
• pp.37-49
• /
• 1992

80 patients who presented at Wonkwang University Dental Hospital with craniomandibular disorders were collected for this study. To observe the occlusal contact pattern such as contact numbers, contact force and presence or absence of anterior occlusal contact, the author used T-Scan system (Tekscan, Inc, U.S.A.) with are computerized occlusal analysing system. And to study the correlation between craniofacial profile and occlusal contact pattern, cephalogram were also taken, The cephalometric items related to growth pattern, jaw bone relation and denture pattern were measured and analysed according to routine method by computerized program. The obtained data were statistically processed with SPSS/PC+ package about anterior contact pattern and its craniofacial relationship. The obtained results were as follows : 1. In terms of growth pattern, patients without anterior tooth contacts showed a tendency to downward growth of craniofacial profile. The value in this subjects were significantly different from the value of patients with anterior tooth contacts in items of low gonial angle, Jarabak ratio, SN to GoMe angle, FMA, occlusal plane to mandibular plane angle and ramus height. 2. In terms of jaw bone relationship, patients without anterior tooth contacts showed a tendency to backward growth of craniofacial profile. The value of this patients were significantly different from the value of patients with anterior tooth contacts in items of SNB, ANB, mandibular plane to anterior cranial base ratio, SNPo, NAPo and APDI items. 3. But in denture pattern, no statistically significant difference by the presence or absence of anterior tooth contacts were showed between this patients groups. 4. From this study, it could be proposed that anterior open bite in the patients with craniomandibular disorders would be originated from not dental discrepancy but skeletal discrepancy.

• Korean Journal of Veterinary Research
• /
• v.40 no.1
• /
• pp.27-34
• /
• 2000

A 20-day-old female Diprosopia in Holstein calf was observsd macroscopically and radiographically. Anterior head duplication(Diprosopia) was observed and all structures caudal to it were normal. She had two muzzles, three eyes, two ears and two tongues. The tongues were joined at their base just posterior and had one hyoid bone. Schistognathia and cleft lips were also observed in the lower jaws. She had an oral cavity, single epiglottis and a laryngeal cavity communicated with one trachea. The cerebral hemispheres were duplicated and fused together in the caudal region. The olfactory and optic nerves were duplicated. The incisive, nasal, pterygoid, parietal, ethmoid bones and vomer were duplicated, respectively. The skull of Diprosopia was shared by an occipital bone. The mandibules, palatines and sphenoid bones were duplicated incompletely. Three orbits and two fontanelles were observed. The medial lacrimal bones and maxillae were duplicated incompletely and fused with each other, respectively. Cleft palates were observed. Medial mandibular mass which was fused together and was duplicated incompletely at the part of its cranial, was shown synchondrosis with the left mandible, but not with the right.

• Imaging Science in Dentistry
• /
• v.33 no.1
• /
• pp.5-14
• /
• 2003

Purpose: To observe the histologic pattern of healing in molar tooth extraction sockets of streptozotocin-induced diabetic rats following irradiation. Materials and Methods: Mature Sprague-Dawley rats were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced by injecting streptozotocin. Control rats were injected with a citrate buffer only. After 5 days, the right maxillary first molar was extracted under general anesthesia from each of the rats. After the extraction, rats in the diabetic-irradiated group were irradiated with a single absorbed dose of 10 Gy to the head and neck region. The rats were killed at 1, 3, 7, 14, 21, and 28 days after treatment. Tissue sections were stained with hematoxylin-eosin and Masson's trichrome. Results: In the diabetic and diabetic-irradiated groups, the early healing process of the socket extraction was similar to the control group, but bone formation was delayed at 7 days after the treatment. In the diabetic-irradiated group, alveolar bone surrounding the extraction socket showed signs of necrosis at 3 days after treatment, and hemorrhage was observed in connective tissue within the extraction socket at 14 days after treatment. Conclusion: This experiment revealed that the healing process of the extraction socket was severely delayed and retarded by irradiation in the diabetic state.

• Archives of Craniofacial Surgery
• /
• v.13 no.1
• /
• pp.50-53
• /
• 2012

Purpose: The Dyke-Davidoff-Masson syndrome is a rare disease entity that was first reported in 1993, and it is characterized by not only the cerebral hemiatrophy that is accompanied by the ipsilateral ventriculomegaly and ipsilateral compensatory osseous hypertrophy, but also the overgrowth of the paranasal sinuses. No studies have attempted to examine it from perspectives of the skull deformity and plastic surgery. Here, we report our case with a review of the literatures. Methods: A 45-year-old man with Dyke-Davidoff-Masson visited our medical institution with nasal bone fracture. Based on the previously taken brain MRI scans, we measured the degree of craniofacial deformity, and the horizontal distance, which is based on the margin of the skull, as well as the falx cerebri. Results: We made a comparison of the degree of craniofacial deformity. This showed that the mean horizontal distance on the axial view was shorter by approximately 28.46%, as compared with that of the left unaffected side. Conclusion: The Dyke-Davidoff-Masson is characterized by a concurrent presence of the atrophy of the cerebral hemisphere, with the cranial deformity. For the reconstruction of the bone and soft-tissue deformity with Dyke-Davidoff-Masson syndrome, it is needed to perform objective assessments.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.42
• /
• pp.31.1-31.7
• /
• 2020

Background: Fibrous dysplasia (FD) is a rare, sporadic, and benign congenital condition in which normal cancellous bone is replaced by fibro-osseous tissue with immature osteogenesis. FD localized in the cranial and facial bones is called craniofacial fibrous dysplasia (CFD). Cystic degeneration in CFD cases is rare; cystic degeneration appearing in both the maxilla and the mandible FD lesion is even rarer. The aim of this article was to report a case of fibrous dysplasia of the mandible and maxilla complicated by nonspecific cystic degeneration. Case presentation: A 30-year-old woman presented with a rare case of non-specific cystic degeneration in a mandible and maxilla FD lesion that occurred 11 years after surgery. She was diagnosed with polyostotic CFD and underwent maxillary and mandibular bone contouring. Cyst enucleation under general anesthesia was performed in the mandibular region due to pain and discomfort. Conclusions: In cases involving non-aggressive and non-invasive FD cystic degeneration in focal areas, conservative treatment is recommended. However, if cystic degeneration of FD develops rapidly and causes discomfort, pain, or dysfunction, surgical treatment should be considered.

• Journal of Korean Neurosurgical Society
• /
• v.48 no.4
• /
• pp.383-387
• /
• 2010

Complete removal of three-compartment trigeminal schwannomas is a challenge to neurosurgeons. To expand exposure of each compartment, the combination and modification of skull base approaches are necessary. The 61-year-old woman was admitted with chronic headache. Preoperative magnetic resonance imaging showed $47{\times}50{\times}40\;mm$-sized tumor originating primarily in the middle cranial fossa extended to the posterior and the infratemporal fossa. We performed operation in five stage; 1. Zygomatic osteotomy, 2. Inferior temporal fossa plate removal and foramen ovale opening, 3. Cavernous sinus opening, 4. Tailored anterior petrosectomy, 5. Meckel's cave opening. Combination of skull base surgery should be concerned according to the patient. In this study, extradural basal extension with zygomatic osteotomy, interdural posterior extension with tailored anterior petrosectomy, and intracavemous exploration are reasonable options for remodeling three-compartment lesion into a single compartment. Tailoring of bone resection and exploring through natural pathway between meningeal layers accomplish single-stage operation for complete removal of tumors.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.16 no.4
• /
• pp.515-520
• /
• 1994

Herpes Zoster is an acute viral infection characterized by the appearance of vesicles that occur on the skin and mucous membrane along the pathway of an involved sensory nerve. Although Herpes zoster is usually as benign viral infection, complications may occur especially when cranial nerves are involved. There are few reports of bony and dental complications by Herpes Zoster infection, all of which were isolated in a single quadrant. These include devitalized teeth, abnormal development of permanent teeth, internal resoption and spontaneous exfoliation of teeth with osteonecrosis of the alveolar bone. No agreement has been reached concerning the pathogenesis of osteonecrosis and tooth exfoliation associated with herpes zoster infection. We recently experienced series of maxillary osteonecrosis and spontaneous teeth exfoliation in patients with Herpes Zoster infection and present two cases with review of literature.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.27 no.1
• /
• pp.263-271
• /
• 1997

The authors diagnosed a 54-year-old male as central mucoepidennoid carcinoma after undergoing clinical, radiological and histopathological examinations. The characteristics were as followed : 1. Clinically, the patient complained of the painless unilateral swelling of the left mandibular molar region and had a pus discharge through the fistula. Painful nodule was palpated on the scalp of the left frontal area and it was regarded as a metastatic lesion. 2. Plain radiographs showed the ill-defined permeative radiolucent lesion. The osteolytic lesions were also detected in the cranial bone, number 9 and 11 ribs, scapula, and vertebral bodies. 3. The mandibular CT and PNS MRI showed the swelling of the left mandible and the enlargement of the several lymph nodes of 1.5 cm in size. 4. Histopathologically, many solid epidermoid type cells were mixed with mucus-secreting cells and they were arranged in duct-like structure. Most of them were epidermoid type, which indicates a high grade tumor. Mucins could be found in mucicamrine staining.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.33 no.6
• /
• pp.540-548
• /
• 2011

Proteus syndrome is a congenital hamartomatous malformation that is characterized by a wide range of deformities, including craniofacial deformities. Proteus syndrome features partial gigantism and asymmetry of the limbs, plantar hyperplasia, hemangiomas, lipomas, lymphangiomas, varicosities, verrucous epidermal nevi, macrocephaly, cranial hyperostosis, and long bone overgrowth. We diagnosed Proteus syndrome in a male patient who visited our hospital with a chief complaint of limited mouth opening and report the case because we obtained a good healing outcome after treating the condition with a corrective osteotomy.