Morphometrics of alveolar process and anatomical structures around inferior maxillary sinus for maxillary implantation / 대한치과보철학회지

STATEMENT OF PROBLEM: Following tooth loss, the edentulous alveolar process of maxilla is affected by irreversible reabsorption process, with progressive sinus pneumatization leads to leaving inadquate bone height for placement of endosseous implants. Grafting the floor of maxillary sinus by sinus lifting surgery and augmentation of autologous bone or alternative bone material is a method of attaining sufficient bone height for maxillary implants placement and has proven to be a highty successful. PURPOSE: This study was undertaken to clarify the morphometric characteristics of inferior maxillary sinus and alveolar process for installation of implants. MATERIAL AND METHOD: Nineteen skulls (37 sinuses, 10M / 9F) obtained from the collection of the department of anatomy and cell biology of Hanyang medical school were studied. The mean age of the deceased was 69.9 years (range 44 to 88 years). The distance between alveolar border and inferior sinus margin at each tooth, the height of alveolar process and the thickness of cortical bone of the outer and inner table of alveolar process and the inferior wall of maxillary sinus were measured. RESULTS AND CONCLUSION: 1. The septum of inferior maxillary sinus were observe 28 sides (76.%) and located at the third molar (52.6%) and the second molar (26.3%). The deepest points of inferior border of maxillary sinus were located the first or second molar. The distance between alveolar margin and the deepest point of inferior maxillary sinus is 9.7 +/- 4.9 mm. 2. The length of the outer table of alveolar process were 4.9-28.2 mm and the shortest point was between the first and the second molors. The thickness of them were 0.9-3.2 mm. The length of the inner table of alveolar process were 7.4-25.8 mm and the shortest point was between the first and the second molars. The thickness of the were 0.9-4.6 mm. The results of this study are useful anatomical data for installing of maxillary implants.

Alterations of PKC theta, NF-kappa B, and AP-1 in Ischemic-reperfused Tibialis Anterior and Soleus Muscles of Rats / 체질인류학회지

Ischemic-reperfusion injury of skeletal muscles takes place in the phase of reperfusion and induces cellular damages through activating various transcription factors and genes, which initiate signal transduction. The purpose of this study was to observe changes of expression of NF-kappa B and AP-1, which are known as a redox sensitive transcription factors in ischemic-reperfused rat skeletal muscles, and PKC theta which activate NF-kappa B and AP-1. Sprague-Dawley male rats of nine, thirty, and sixty-five weeks old were divided into control and ischemia groups. Ischemia was performed by occlusion of left common iliac artery for 4 hours using rodent vascular clamps. The animals were sacrificed at hours 0, 1, 3 and 6 after onset of reperfusion and tibialis anterior and soleus muscles were removed. The distributions of PKC theta, NF-kappa B, and AP-1 immunoreactivity (IMR) were examined using immunohistochemical methods. The results as follows; In control groups, PKC theta IMR was decreased with age and was higher in tibialis anterior than that in soleus muscles. In ischemia groups, PKC theta IMR was increased with age and was higher in soleus than that in tibialis anterior muscles. In control groups, NF-kappa B IMR was decreased with age. In ischemia groups, NF-kappa B IMR was increased with age and was higher in soleus than that in tibialis anterior muscles. In control groups, AP-1 IMR was decreased with age. In ischemia groups, AP-1 IMR was increased with age and was higher in tibialis anterior than that in soleus muscles. Increase or decrease of PKC theta IMR was associated with the increase or decrease of NF-kappa B and AP-1 IMR in ischemic-reperfused rat skeletal muscles, respectively. These results suggested that the increased expression of PKC theta may induce the upregulations of NF-kappa B and AP-1 in ischemic-reperfusion injury of rat skeletal muscle. It is also suggested that the ischemic injury may be increased with age, and tibialis anterior muscle is more susceptabile to ischemic-reperfusion injury than soleus muscle.

A study on the various implant systems using the finite element stress analysis / 대한치과보철학회지

STATEMENT OF PROBLEM: To conduct a successful function of implant prosthesis in oral cavity for a long time, it is important that not only structure materials must have the biocompatibility, but also the prosthesis must be designed for the stress, which is occurred in occlusion, to scatter adequately within the limitation of alveolar bone around implant and bio-capacity of load support. Now implant which is used in clinical part has a very various shapes, recently, the fixture that has tapered form of internal connection is often selected. However, the stress analysis of fixtures still requires more studies. PURPOSE: The purpose of this study is to stress analysis of the implant prosthesis according to the different implant systems using finite element method. MATERIAL AND METHODS: This study we make the finite element models that three type implant fixture; Branemark, Camlog, Frialit-2 were placed in the area of mandibular first premolar and prosthesis fabricated, which we compared with stress distribution using the finite element analysis under two loading condition. CONCLUSION: The conclusions were as follows: 1. In all implant system, oblique loading of maximum Von mises stress of implant, alveolar bone and crown is higher than vertical loading of those. 2. Regardless of loading conditions and the type of system, cortical bone which contacts with implant fixture top area has high stress, and cancellous bone has a little stress. 3. Under the vertical loading, maximum Von mises stress of Branemark system with external connection type and tapered form is lower than Camlog and Frialit-2 system with internal connection type and tapered form, but under oblique loading Camlog and Frialit-2 system is lower than Branemark system.