• Journal of the korean academy of Pediatric Dentistry
• /
• v.29 no.1
• /
• pp.44-50
• /
• 2002

Apert syndrome is a kind of congenital-acrocephalosyndactyly syndrome which was first reported by Apert in 1906 and characterized by its acrocephaly and syndactyly. Clinical characteristic features are cone-shaped skull morphology due to early fusion of coronal suture, fusion of fingers of hands and toes of feet. It is an autosomal dominant-heritable syndrome. Due to hypo-development of midface region, Apert syndrome patients have a tendency to have ocular proptosis, hypertelorism, maxillary deficiency. High palate and soft palate cleft are common findings in these patients. In general, mandibular growth pattern is normal, but relative maxillary deficiency exaggerates mandibular forward position, so relative mandibular prognathism is inevitable. Narrow maxillary and mandibular dental arch worsen teeth alignment and crowding. Skeletal malocclusion and open bite are also common. This is a case report of a Korean 3 year 1 month male Apert syndrome child referred by department of plastic surgeon for the possibility of orthodontic treatment. General features of Apert syndrome, patient's medical history, radiographic evaluation, clinical examination, orthodontic and surgical treatment planning are discussed in this report.

• Progress in Medical Physics
• /
• v.13 no.1
• /
• pp.9-14
• /
• 2002

We invented the newly developed Fractionated Stereotactic Radiotherapy(F.S.R.T) system using combined techniques of couch mounting and pedestal mounting system. Head fixation frame consists of a milled alluminium alloy(duralumin) and is placed to the couch. This frame immobilized patient head using the dental bite, 3.2 mm frontal and occipital thermoplastic mask. To evaluate the coordinate of target isocenter, Brown-Revert-Walls C.T localizer can be attached to this frame. And also, we developed the frame mounting system by developing the modification of pedestal mounting system. This system is fixed to couch floor and can be used to evaluate the isocenteric accuracy of gantry, couch and collimator in Q.A procedure. In order to measure the relocation accuracy, the acrylic phantom and the accurate pointers have been made. The repositioning of the targets in the phantom were estimated by comparing C.T coordinates and E.C.L portal films taken with anterior-posterior and right-left direction. From the results of experiments, the average distance errors between the target isocenter and its mean position were 0.71$\pm$0.19 for lateral, 0.45$\pm$0.15 for inferior-superior, 0.63$\pm$0.18 for anterior-posterior. And the maximum distance error was less than 1.3 mm. The new head fixation frame and frame mounting system were non-invasive, accurately relocatable, easy to use, very light and well tolerable by the results of phantom tests. The major advantage of using this frame mounting system is complete access to any point in the Patients cranium especially posterior direction

• The Korean Journal of Zoology
• /
• v.39 no.4
• /
• pp.437-446
• /
• 1996

The courtship and fighting behaviors and the sexual dimorphism of the salamander Hynohius leechil were studied. The parameters, snout vent length, body length (from snout to tail tip), and proportion of snout vent length to body size were larger in the female than the male. Five physical parameter in males were significantly correlated with one another, body length, snout vent length, head width, tail vent length, and tall depth, while all, except tail depth, were significantly correlated in females. Sexual behavior of H. leechIl involved external fertilization and consisted of three stages, identifying the female, aifrading the female, and insemination. The identification stage consisted of a positive advance by the male toward the female and display of snout contact. The male attracted the female with chin rubbing, tail undulation, smelling, and digging displays. The insemination process consisted of four phases, amplex, separating egg sacs from the female's cloacal, fertilizing eggs, and post fertilization. liighting behaviors were quite simple. The attacking male would generally bite the opposite male's upper chin or hind limbs and then shakes his head two or three times. The bitten male, which in most cases was of a dissimilar body size, quicidy escaped from the attacking male. After fighting, winning male usually displayed rapid tail undulation.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.13 no.1
• /
• pp.117-127
• /
• 1991

When open reduction of maxilla fractures is postponed due to concurrent life-threatening injuries, delayed union may result with malunion or nonunion. If delayed malunion is occurred, significant facial deformity may result, including a dished-out face, irregular retromaxillism with Angle's class III malocclusion, open anterior bite, nasal collapse, telecanthus and malar flattening. The treatment planning for this problem includes cephalometric evaluation anterior and lateral tomograms, dental casts, orthodontic planning, dental planning and use of impression tray to rupture the fibrous tissue casts, orthodontic planning, dental planning and use of impression tray to rupture the fibrous tissue attachment at the fracture site. In this paper, one case presented a 58-year-old female patient with maxilla retrusion after comminuted fracture, who was treated with orthodontic methods of maxillary protraction headgear and Plaster headcap, whereas the other two cases were about male patients who were treated principally with surgically open reduction or Le Fort I-controlled transverse osteotomy with iliac bone graft.

• The Journal of Korean Academy of Prosthodontics
• /
• v.54 no.1
• /
• pp.49-56
• /
• 2016

Excessive occlusal wear can result in unacceptable damage to the residual teeth structure, anterior guidance and masticatory function. An 86-year-old man presented with worn dentition and anterior deep bite due to loss of the posterior support. Two implants covered by Korean national health insurance, fixed partial denture and direct composite resin were used to restore the dentition, instead of removable prosthesis. The occlusal vertical dimension was increased by 2 mm in the premolar area and shortened dental arch concept was applied. This treatment was a less expensive alternative to full-mouth rehabilitation with positive esthetic and functional outcomes after 7 months of follow-up.

• The Journal of Korean Academy of Prosthodontics
• /
• v.35 no.3
• /
• pp.517-534
• /
• 1997

It has been held that excessive mechanical forces to the osseous and soft tissues of the TMJ result in joint dysfunction. Understanding the stress pattern on TMJ is very important in TMJ research. But, it is very difficult to measure directly the biomechanical stress distribution in the TMJ when the mandible is loaded. Therefore, stress distribution in the TMJ during functional movement was studied through animal experiment or mathematical model. It was observed and compared the stress distribution occuring in the working and balancing condyle when lower right canine, lower right first molar and lower right second molar were clenched by the three dimensional finite element analysis. Also, stress distribution in the working and balancing condyles were observed and compared when $20^{\circ}$ forward and buccal bite forces were applied to the first molar. The results were as follows : 1. Stress distribution in the condyles during unilateral clenching of the first molar, second molar, canine showed no difference. In the working condyle, tensile force was concentrated on the lateral aspect of the condylar articular surface and condylar neck. And compressive force was concentrated on the anteromedial and lateral aspect of condyle. In the balancing condyle, tensile and compressive forces were concentrated on the lateral aspect of the condylar articular surface and stress transmission to the temporal bone was not observed. 2. When lateral forces were applied to the first molar, tensile forces were concentrated on the medial aspect of the condylar neck and condylar posterior surface in working and balancing condyle. Compressive force was concentrated on the anteromedial and lateral surface of the condyle and stress transmission to the temporal bone was not observed. 3. During unilateral clenching, stress in the working condyle decreased as the occlusal load moved posteriorly while the stress in the balancing condyle increased. when lateral force was applied to first molar, the incremental amount of stress was greater than vertical load. 4. During unilateral clenching, the average balancing/working condyle stress ratio was 2.52. There was a greater concentration of stress in the balancing condyle. The ratio increased as the occlusal load moved posteriorly and decreased considerably when lateral forces were applied to the first molar.

• Restorative Dentistry and Endodontics
• /
• v.35 no.6
• /
• pp.436-444
• /
• 2010

Objectives: This study aimed to assess prospectively the clinical outcome of nonsurgical endodontic treatment and identify patient- and tooth-related factors, rather than treatment-related factors, that were the best predictors of this outcome. Materials and Methods: The inception cohort comprised 441 teeth (320 patients) and 175 teeth (123 patients) were followed up for 1-2 years. Age, gender, presence of medical disease, number of canals, previous endodontic treatment, presence of sensitivity and pain, pulp vitality, swelling or sinus tract of pulpal origin on the gingiva, periapical radiolucency and tendency of unilateral bite on the affected tooth were recorded at treatment start. Results: The outcome was classified on the basis of periapical radiolucency as healed or non healed. The overall healed rate in these cases, including nonsurgical retreatment, was 81.1%. Four tooth-related factors had a negative impact in the bivariate analysis: previous endodontic treatment, necrotic pulp, preoperative gingival swelling or sinus tract of pulpal origin, and preoperative periapical radiolucency. Stepwise logistic regression analysis including patient-, tooth-related factors and level of the root canal filling as a treatment-related factor showed that preoperative gingival lesion (odds ratio [OR]: 4.4; p = 0.005), preoperative periapical radiolucency (OR: 3.6; p = 0.011), and $\leq$ 1-2 mm under root filling length (OR: 9.6; p = 0.012) were significant predictors of failure. Conclusions: A preoperative gingival lesion of pulpal origin can influence the outcome of nonsurgical endodontic treatment in addition to preoperative periapical radiolucency.

• The Journal of Korean Academy of Prosthodontics
• /
• v.57 no.4
• /
• pp.448-455
• /
• 2019

Ameloblastoma is a benign odontogenic epithelial tumor with high recurrence rate and requires extensive resection of the surrounding tissue and reconstruction of defect site. Because of the anatomical limitation of the reconstruction site, prosthetic treatment with implants is the first recommendation. This is a case of prosthetic restoration of the reconstruction site with implant fixed prosthesis in patient who underwent mandibular resection and iliac bone reconstruction due to ameloblastoma. However 14 months after completion of implant prosthesis, adjacent natural tooth erupted unexpectedly, resulting in 1mm infra-occlusion occurred including posterior implant prosthesis and anterior natural teeth. In adults, implant infra-occlusion may occur due to residual growth after placement of the maxillary anterior implant. But this case, hypo-occlusion of molar implant and open bite of anterior natural teeth is occurred due to extrusion of adjacent tooth, is rare. Thus we report the treatment process including orthodontic treatment with intrusion of the posterior tooth, and investigate the causes of sudden, unexpected tooth extrusion.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.4
• /
• pp.478-486
• /
• 2021

This report demonstrates a method of generating a chair-side and computer-aided template for implant surgery based on the Top-Down and restoration-driven concept. Compared to the traditional CAD-CAM process which requires multiple steps to be taken between dental clinic and laboratory, this alternative procedure, VARO guide system (VARO Guide, CAD, Pre-Guide, VARO-mill, NeoBiotech, Seoul, South Korea) enables accurate and patient-friendly implant surgery as well as immediate provisional restoration in a single visit. First, bite-registration at centric jaw relation and CBCT were taken using the Pre-Guide. The CBCT data was then reorganized directly through the chair-side CAD, and we could determine the most appropriate 3-dimensional position of implant. The STL file was extracted and put into the chair-side CAM (VARO-mill) to fabricate a VARO. This surgical guide allowed the implants to be accurately positioned into the planned sites within an hour.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.2
• /
• pp.238-247
• /
• 2021

Congenital tooth agenesis is the most common developmental dental anomaly, of which oligodontia is defined as the absence of six or more permanent teeth, except the third molars. Tooth agenesis causes malocclusion, alveolar atrophy, aesthetic and psychosocial problems. This clinical report describes a multidisciplinary treatment for a patient diagnosed as oligodontia, who exhibited absence of 14 permanent teeth, atrophy of maxillary alveolar bone, and mandibular protrusion. Restoration space was secured and tooth axis was improved by the extraction of deciduous teeth and orthodontic treatment. However, edge-to-edge bite of posterior teeth and arch dimension discrepancy due to atrophic maxilla was remained. To restore the aesthetics and functionality, implant retained prosthesis was planned. Considering minimal bone grafts, location and number of dental implants and prostheses design were determined. Through the gradual adjustment of provisional restoration, the appropriate centric and eccentric occlusion was reflected into a definitive prosthesis. Currently, stable functional results were attained, however, regular follow up and maintenance care over lifetimes should be performed.