• The Journal of Advanced Prosthodontics
• /
• v.5 no.3
• /
• pp.326-332
• /
• 2013

PURPOSE. The purpose of this study was to compare stress distributions of implant-supported crown placed in fibula bone model with those in intact mandible model using three-dimensional finite element analysis. MATERIALS AND METHODS. Two three-dimensional finite element models were created to analyze biomechanical behaviors of implant-supported crowns placed in intact mandible and fibula model. The finite element models were generated from patient's computed tomography data. The model for grafted fibula was composed of fibula block, dental implant system, and implant-supported crown. In the mandible model, same components with identical geometries with the fibula model were used except that the mandible replaced the fibula. Vertical and oblique loadings were applied on the crowns. The highest von Mises stresses were investigated and stress distributions of the two models were analyzed. RESULTS. Overall stress distributions in the two models were similar. The highest von Mises stress values were higher in the mandible model than in the fibula model. In the individual prosthodontic components there was no prominent difference between models. The stress concentrations occurred in cortical bones in both models and the effect of bicortical anchorage could be found in the fibula model. CONCLUSION. Using finite element analysis it was shown that the implant-supported crown placed in free fibula graft might function successfully in terms of biomechanical behavior.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.35 no.1
• /
• pp.55-59
• /
• 2013

In the oral and maxillofacial area, bone defects are created by various reasons and demand for bone grafts, while dental implant implantation has been increased consistently. To solve these problems, there has been development of autogenous tooth-bone graft material (AutoBT$^{(R)}$, Korea Tooth Bank Co., Korea), and we have collected ground reasons to substitute free autobone graft with this material in clinical use. This autogenous tooth-bone graft material is produced in powder type and block type. Block type is useful in esthetic reconstruction of the defect site and vertical and horizontal augmentation of alveolar bone because this type has high strength value, well maintained shape and is less absorbed. Therefore, the author of this study gained favorable result by grafting the block type autogenous tooth-bone graft material after dental implant implantation on the bone defects of the mandibular molar extraction site. Moreover, the author represents this case with literature review after confirming bone remodeling on the computed tomography image and by histological analysis.

• Archives of Craniofacial Surgery
• /
• v.18 no.2
• /
• pp.132-136
• /
• 2017

Frey's syndrome and infra-auricular depressed deformities are the ones of the most common complications that can occur after total parotidectomy. We report 1 case of pleomorphic adenoma occurred in the deep lobe that obtained good results from using acellular dermal matrix (ADM) after total parotidectomy. A 24-year-old man visited the hospital with oval shape mass in right mandibular angle which of 4 cm in size was found in the deep lobe of right parotid gland from Magnetic resonance imaging scanning and a pleomorphic adenoma was suspected. A total parotidectomy was performed while preserving the facial nerve. The material known as ADM were placed in the depressed part from where the mass was removed, and the site was sutured. The surgery site was healed well without any complications such as Frey's syndrome or infra-auricular depressed deformities. The pathological result was confirmed as pleomorphic adenoma. In addition to these advantages, it does not have little potential of deformation by the gravity after the surgery, and there is no restraint on circulation, which makes fabrication free and each deformation into various shapes can be described as another advantage of the reconstruction using the ADM.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.17 no.3
• /
• pp.220-230
• /
• 1995

In this report, a case is presented in which resected mandible was reconstructed immediately with vascularized bone graft and adjunctive implantation of osseointegrated dental implants. The primary was central odontogenic myxoma of mandible extending from symphysis to the left condylar neck. The hemimandibulectomy defect was restored with free fibular flap. Three months after 1st surgery, the transplant received five $IMZ^{(R)}$ implants. The masticatory function was restored with the implant borne denture. The result including facial appearance was very satisfactory.

• Archives of Plastic Surgery
• /
• v.37 no.6
• /
• pp.819-822
• /
• 2010

Purpose: Basal cell nevus syndrome (BCNS), also known as Gorlin syndrome, is a rare autosomal dominant disorder. It is characterized by complex neoplastic syndrome with multisystemic manifestations, involving six major features. This article presents a rare genetic disorder and usage of the author's methods for odontogenic keratocyst, developed in the maxillary sinus. Methods: A 67-year-old man was presented with large calcified maxillary mass and multisystemic manifestations and findings that matched with basal cell nevus syndrome. The calcified maxillary mass was removed via the versatile maxillary window and maxillary bone segment was repositioned. Results: Histopathologic findings revealed that maxillary and mandibular lesions were odontogenic keratocysts and the skin lesions were basal cell carcinoma. Conclusion: Basal cell nevus syndrome is a rare genetic disease that requires surveillance and care for basal cell carcinoma and multisystemic problems. The author's method was satisfactory for maxillary odontogenic keratocyst in the aspect of the approach and reconstruction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.45 no.4
• /
• pp.180-185
• /
• 2019

Masson's tumor or intravascular papillary endothelial hyperplasia is an inflammatory soft tissue lesion that rarely occurs in the maxillofacial region and skeletal system. Precise clinical and para-clinical investigation is necessary for the accurate diagnosis and correct treatment of this lesion. This paper presents a massive intravascular papillary endothelial hyperplasia lesion in the bony tissue of the mandible. Histopathology features, clinical appearance, and suitable management are discussed, with a complete review of the literature. The patient underwent composite resection of the lesion as well as reconstruction. No recurrence was observed during 6 years of follow-up. To the best of our knowledge, this is the fourth case of Masson's tumor in mandibular skeletal tissue, which has unique and distinctive features due to its size and location. A rare occurrence in skeletal tissue, complex clinical presentations, and complicated histopathologic findings present diagnostic challenges for treatment of this lesion.

• Archives of Craniofacial Surgery
• /
• v.24 no.6
• /
• pp.251-259
• /
• 2023

Background: Periosteum-mediated bone regeneration (PMBR) is a recognized method for mandibular reconstruction. Despite its unpredictable nature and the limited degree to which it is understood, it does not share the concerns of developmental changes to donor and recipient tissues that other treatment options do. The definitive role of the periosteum in bone regeneration in any mammal remains largely unexplored. The purpose of this study was to identify the genetic determinants of PMBR in mammals through a systematic review. Methods: Our search methodology was designed in accordance with the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. We conducted a quality assessment of each publication, and evaluated the differences in gene expression between days 7 and 15. Results: A total of four studies satisfied the inclusion criteria. The subjects and tissues examined in these studies were Wistar rat calvaria in two studies, mini-pigs in one study, and calves and mice in one study. Three out of the four studies achieved the necessary quality score of ≥ 3. Gene expression analysis showed increased activity of genes responsible for angiogenesis, cytokine activities, and immune-inflammatory responses on day 7. Additionally, genes related to skeletal development and signaling pathways were upregulated on day 15. Conclusions: The results suggest that skeletal morphogenesis is regulated by genes associated with skeletal development, and the gene expression patterns of PMBR may be characterized by specific pathways.

• Restorative Dentistry and Endodontics
• /
• v.27 no.4
• /
• pp.421-431
• /
• 2002

C-shaped canal configuration is very difficult to treat because that clues about preoperative canal anatomy cannot be ascertained from clinical crown morphology and limited information can be derived from radiographic examination. This study was done to get more informations about the root and canal configuration of C-shape root by 3-dimensionally reconstructing for the purpose of enhancing success rate of endodontic treatment. 30 mandibular molars with C-shaped root were selected. Six photo images from occlusal, apical, mesial, distal, buccal, lingual directions and radiographic view were taken as preoperative ones to compare them with 3-D image. After crown reduction to the level of 1-2mm over pulpal floor was performed, teeth were stored in 5.25% sodium hypochlorite solution for the removal of pulp tissue and debris. They were cleaned under running water, allowed to bench dry and embedded in a self-curing resin. This resin block was serially ground with a microtome (Accutom-50, Struers, Denmark) and the image of each level was recorded by digital camera (FinePix S1-pro, Fuji Co., Japan). The thickness of each section was 0.25mm. Photographs of serial sections through all root canal were digitized using Adobe Photoshop 5.0 and then minimum thickness of open and closed sites were measured (open site is the surface containing occluso-apical groove closed site is oppsite). After dizitization using 3-D Doctor (Able software Corp, USA). 3D reconstruction of the outer surface of tooth and the inner surface of pulp space was made. Canal classsification of C-shaped roots was performed from this 3-D reconstructed image. The results were as follows : 1. Most C-shape rooted teeth showed lingual groove (28/30). 2 According to Vertuccis' calssification, type I, II, III, IV, VII were observed. but also new canal types suck as 2-3-2, 1-2-3-2. 2-3-2-1, 2-3-2-3 were shown. 3 There was little difference in minimum thickness on coronal and apical portions, but open site were thinner than closed site on mid portion. Conclusively, 3D reconstruction method could make the exact configurations of C-shape root possible to be visualized and analyzed from multi-directions. Data from minimum thickness recommend cleaning and shaping be more carefully done on dangerous mid portion.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.31 no.5
• /
• pp.409-416
• /
• 2005

Purpose of study: The temporomandibular joint (TMJ) occupies a key functional role in mastication and contributes to normal deglutition, speech as well as cosmesis. When a large amount of mandible including the condyle head is resected, it is very difficult to reconstruct it as a functional unit. In this retrospective study, we present the functional, radiographic and cosmetic results of reconstructed temporomandibular joint using free fibular flap. Patients and Methods: Total 12 patients (M:F = 6:6) who underwent condylar reconstruction with the fibular flap were interviewed and examined by radiographs and Bio-PAK$^{(R)}$. Mean follow up periods was $47.7{\pm}20.0$ months and the average age was $38.7{\pm}15.3$ years. Remodeling of condyle and function of TMJ were evaluated and facial contour was judged subjectively. Results: All flaps were viable and no immediate postoperative complication had happened. One patient showed decreased mouth opening, so interpositional gap arthroplasty was performed. The resorption rates of reconstructed fibular were minimal and the condyle heads were changed into domeshaped neocondyle after 2 years. All patients had normal diet and no speech difficulty was reported. Nine patients were satisfied with their facial contour but three patients complained about the depression of cheek. Conclusion: The reconstruction of TMJ with free fibular flap was reliable methods and very effective means of restoring mandibular function. The functional and morphologic results were excellent and showed little complications.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.28 no.1
• /
• pp.47-58
• /
• 1998

The purpose of this study was to investigate an influence of the change of central panoramic curves on the image reconstruction in the dental implant CT. The author designed three experimental groups according to the location of central panoramic curve. In group A, central panoramic curve was determined as the curve connecting the center of roots from the first premolar to the first molar. In group B, central panoramic curve was determined as the line connecting the lingual cortical plate at the level of the mesial aspect of the first premolar with the buccal cortical plate at the level of the mesial aspect of the first molar. In Group C, central panoramic curve was determined as the line connecting the buccal cortical plate at the level of the mesial aspect of the first premolar with the lingual cortical plate at the level of the mesial aspect of the first molar. Twenty four reformatted CT images was acquired from four mandibles embedded in the resin block and twenty four contact radiographs of dog specimens were acquired. Each Image was processed under Adobe Photoshop program analysed by MSPA(mandible/maxilla shape pattern analysis) variables such as MXVD, MXHD, UHD, MHD, and LHD. The obtained results were as follows ; 1. The mean of MXVD variable was 19.9, 20.2, and 20.0 in group A, B, and C, respectively, which were smaller than actual value 20.5. But, there was no significant difference among 3 groups (p>0.05). 2. The mean of MXHD, UHD, MHD, and LHD variables in group A, B, and C was 11.9, 12.2, and 12.3; 9.3, 9.5, and 9.6; 10.0, 10.3, and 10.3; 9.2, 9.3, and 9.4 respectively which were equal to or greater than the actual value 11.8, 9.3, 10.0, and 9.2. But, there was no significant difference among 3 groups (p>0.05). 3. The number of noneffective observations with difference over or under 1 mm with comparison to the actual value was 24(20％), 58(48.3％), and 52(43.3％), respectively, in group A, B, and C. 4. In group A, the number of observations over 1 mm and under 1 mm was 9 and 15, respectively, but in group Band C, the number of observations over 1 mm was more than under 1 mm.