No abstract available.

This study was undertaken to investigate the relation between orthodontic force magnitude and the amount of tooth movement. And more light force application for reducing root resorption. Twenty-four rats were divided into three experimental groups(A, B, C) based on force magnitude and application method. Springs of 50g force were applied to A group, spring of 100g force were applied to B group and springs of 25g force were applied to C group initially, and after 4 days springs of C group were changed to springs of 50g force. Two kinds of sentalloy(R) (GAC U.S.A) closed coil spring, 50g and 100g, were used. And we made 25g springs by heat treatment process of 50g spring. Each spring was inserted between the maxillary central incisor and the maxillary left first molar. Amounts of tooth movement were measured everyday by digital caliper(Digimatic(R) , Mitutoyo, Japan) under inhalation anesthesia for 15 days, all rats were sacrificed and histological sample were obtained with Hematoxyline-Eosin stan and Masson's trichrome stain. Following conclusion were made : 1. Group B showed the mean cumulative tooth movement of 2.19+/-0.41mm at 15th day, which was greatest among three groups, followed by group C(2.06+/-0101mm), group A(1.90+/-0.49mm) respectively. However, there was no statistically difference among three groups. 2. All groups showed general tooth movement pattern and A, B, C group finished lag phase at 9th, 8th, 7th day, but three was no statistical significance. 3. Group A, B, C showed root resorption and especially group B showed the most severe root resorption and group C showed milder root resorpting than other groups. According to the above results, large initial force with the development of a fairly widespread hyalinized zone may cause severe root resorption, so initial force should be applied lightly to reduce hyalinized area and eventually root resorption and then increased force will induce efficient tooth movement.
Anesthesia, Inhalation ; Animals ; Hot Temperature ; Hyalin ; Incisor ; Molar ; Rats* ; Root Resorption* ; Tooth Movement* ; Tooth*

Decompression ; Follow-Up Studies ; Head ; Headache ; Humans ; Incidence ; Inflammation ; Jaw ; Joints ; Mandibular Condyle ; Recurrence ; Synovial Fluid ; Temporomandibular Joint

Malocclusion

Female ; Follow-Up Studies ; Headache ; Humans ; Incidence ; Neck ; Neck Pain ; Shoulder Pain ; Temporomandibular Joint

No abstract available.
Teratoma*

Matrix metalloproteinases (MMPs) play an important role in the normal morphogenesis, maintenance, and repair of matrix and also have important functions in pathologic conditions characterized by excessive degradation of extracellular matrix, such as rheumatoid arthritis, osteoarthritis, periodontitis and in tumor invasion and metastasis. In this study, expression of MMP-1 and -2 mRNA in retrodiscal tissue of the temporomandibular joint (TMJ) was examined and compared with magnetic resonance imaging (MRI) and surgical findings. MMP mRNAs in the retrodiscal tissue samples were detected by reverse transcription - polymerase chain reaction. TMJ internal derangement (ID) was categorized as normal disc position, disc displacement with reduction, early stage of disc displacement without reduction (DDsR) and late stage of DDsR. TMJ osteoarthrosis (OA) was classified with normal, mild and advanced OA. The amount of synovial fluid collection was divided into not detected, small, large and extremely large amount on MR T2-weighted imaging. Perforation and adhesion were examined during open surgery of the TMJ. Six out of 37 samples were excluded because of little amount of extracted total mRNA. MMP-2 mRNA was detected whole joints, and so the MMP-2 mRNA seems to be expressed normally in retrodiscal tissue. However, MMP-1 mRNA was expressed in 8 of 31 joints. Frequencies of MMP-1 mRNA expression according to the TMJ IDs, amount of synovial fluid and surgical findings made no significant difference. MMP-1 mRNA was detected more frequently in OA groups (7/16 joints, 43.8%) than in normal bony structure group (1/15,joints, 6.7%). Expression of MMP-1 mRNA in retrodiscal tissue might be related with OA of the TMJ.
Arthritis, Rheumatoid ; Collagenases ; Extracellular Matrix ; Gelatinases ; Joints ; Magnetic Resonance Imaging ; Matrix Metalloproteinase 1* ; Matrix Metalloproteinases ; Morphogenesis ; Neoplasm Metastasis ; Osteoarthritis ; Periodontitis ; Polymerase Chain Reaction ; Reverse Transcription ; RNA, Messenger* ; Synovial Fluid ; Temporomandibular Joint*

Lesions of the skull vault are often incidentally encountered during in plain radiography, CT, and MR imaging of the brain and benign lesions are more common than primary malignancies. The usefulness of plain skull films is limited, but when combined with CT or MRI, there is a high probability of accurate diagnosis. The aim of this essay is to describe a wide range of cranial lesions and to illustrate their distinguishing features.
Brain ; Diagnosis ; Magnetic Resonance Imaging ; Radiography ; Skull*