Optimization of orthodontic microimplant thread design / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to optimize the thread pattern of orthodontic microimplants. METHODS: In search of an optimal thread for orthodontic microimplants, an objective function stability quotient (SQ) was built and solved which will help increase the stability and torsional strength of microimplants while reducing the bone damage during insertion. Selecting the AbsoAnchor SH1312-7 microimplant (Dentos Inc., Daegu, Korea) as a control, and using the thread height (h) and pitch (p) as design parameters, new thread designs with optimal combination of h and p combination were developed. Design soundness of the new threads were examined through insertion strain analyses using 3D finite element simulation, torque test, and clinical test. RESULTS: Solving the function SQ, four new models with optimized thread designs were developed (h200p6, h225p7, h250p8, and h275p8). Finite element analysis has shown that these new designs may cause less bone damage during insertion. The torsional strength of two models h200p6 and h225p7 were significantly higher than the control. On the other hand, clinical test of models h200p6 and h250p8 had similar success rates when compared to the control. CONCLUSIONS: Overall, the new thread designs exhibited better performance than the control which indicated that the optimization methodology may be a useful tool when designing orthodontic microimplant threads.

Subdural Strip Electrode Studies in Temporal Lobe Epilepsy: Relation between Interhemispheric Propagation Time and Surgical Outcome

BACKGROUND: We evaluated whether the time required for a seizure to spread contralaterally, interhemispheric propagation time (IHSPT) could be related to post-surgical outcome in temporal lobectomy. METHODS: We performed a retrospective study of 28 patients. All patients had previously undergone a phase I presurgical evaluation including MRI and video-EEG monitoring with scalp and sphenoidal electrodes, which strongly suggested the diagnosis of mesial temporal lobe epilepsy, but proved inadequate to lateralize the epileptogenic zone. All patients performed the video-EEG monitoring with bilateral subdural strip electrodes on their basal and mesial temporal area and unilateral temporal lobectomy with a minimum of 1-year follow up postoperatively. IHSPT was divided into two categories, 0~5.0 seconds, 5.1 seconds or longer. RESULTS: Sixteen patients (57.1%) were seizure free and 12 suffered persistent seizures. A prolonged IHSPT (> 5.0sec) significantly correlated with a favorable surgical outcome (P = 0.05). Hippocampal atrophy on MRI significantly correlated with prolonged IHSPT (P<0.05). CONCLUSIONS: Our result suggests that hippocampal atrophy on MRI and IHSPT can predict the surgical outcome and may be used as the selection criteria of temporal lobectomy for patients with intractable temporal lobe epilepsy.

A Case of Recurrent Bickerstaff's Brainstem Encephalitis with an Overlap of Guillain-Barre Syndrome

Bickerstaff 's brainstem encephalitis (BBE) is characterized by acute ophthalmoplegia and ataxia. Some patients with BBE show mental changes, pyramidal signs and sensory disturbance. A forty-three year old woman was diagnosed as BBE in 1996. In 2000, she admitted again with complaints of ataxia and ophthalmoplegia. She was diagnosed as recurrent BBE and an overlap of Guillain-Barre syndrome (GBS). This is the first case of an overlap of BBE and GBS, as well as BBE in Korea.

The effect of a static magnetic field on the bone nodule formation of MC3T3-E1 cells / 대한치과교정학회지

To evaluate the effect of a static magnetic field on the bone producing potential of MC3T3 El cells, the alkaline phosphatase activity was measured after the cells having been cultured under 76.4mT static magnetic field using a SmCos magnets for 5days, 7days, lldays, 15days and 2ldays for each cell culture group. Also, the amount of bone nodule stained with Alizarin red S was observed. The results were as follows. · The alkaline phosphatase activity of the 7, 11, and 15 days group among the experimental groups was decreased as compared with the control groups, and the decrease of alkaline phosphatase activity in the 11 days group was the most evident among them. · Any stained bone nodules of both groups had not been observed until the 11th day. The stained bone nodules in the control groups were found on the 15th day, but not in the experimental groups. The stained bone nodules were observed in both groups on the 21st day, but the control groups have more bone nodules than the experimental groups.

Papineau's Cancellous Bone Graft: 3 Cases Report / 대한정형외과학회잡지

2 cases of extensive open tibia fracture and 1 case of infecture of tibia were treated by Papineaus cancellous bone graft at department of orthopedic surgery, Inchon Christian Hospital from Dec. 1982 to Dec. 1984. 1. Bony stability was obtained by pin and resin method in 1 case, and the others were fixed by Hoffmanns external fixator. 2. Wound was healed spontaneously in case 1 and by skin graft in 2 cases. 3. Initial weight bearing started after evidence of radiological union about 12 weeks after bone graft with the supply of long leg brace in 2 cases and one was not supported.

Clinical Observation on Tuberculosis of the Bone and Joint / 대한정형외과학회잡지

One hundred and seventy-two cases of tuberculosis of the bones and joints were treated at the department of orthopedic surgery, Inchon Christian Hospital during the 3 years and 10 months from March, 1979, to December, 1982. The results obtained were as followings: 1. The incidence was decreased progressively 1.92% in 1980 to 1.18 in 1982. 2. Tuberculous lesions involved spine(50.58%), knee(16.28%), hip(13.37%), ankle(2.33%) and greater trochanter(2.33%) in order. 3. Age and sex distribution were not remarkable. 4. The main associated tuberculous lesions were pulmonary tuberculosis and tuberculous pleurisy (20.65%). Therefore, pulmonary problems should be always carefully investigated in every case of skeletal tuberculosis. 5. Average duration of disease was one year and 3.5 months, average hospital days was one month. 6. Initial miss diagnosis of lesions ultimately proved to be tuberculosis. Rheumatoid arthritis:13 cases, Osteoarthritis : 3 cases, Herniated lumbar disc: 3 cases, Cellulitis :2 cases, Neoplasm :2 cases. Early diagnosis is essential since proper therapy is available and far advanced destruction, long suffering and disability can be avoided. 7. Post operative complication was mainly due to failure of bone graft in tuberculous spondylitis and was draining sinus formation and wound disruption in other skeletal tuberculosis. 8. The result of treatment of skeletal tuberculosis from conservative methods were relatively poor. The corroboratory care of skeletal tuberculosis can be obtained by extensive surgery.

A Clinical Study of the Ankle Fractures / 대한정형외과학회잡지

A clinical analysis was done on 129 patients (131 cases) of the ankle fractures that were admitted and treated in Orthopedic Department, Inchon Christian Hospital from January 1973 to December 1980. The following results were obtained: l. Of the 129 patients, male was 104 patients and female 25 patients, the average age of the patients was 37. 2. The main cause of the injuries was traffic accident (38.2%), and the remain causes were industrial accident (28.2%), fall down (18.3%), slip down (11.5%), and sports injury (3.8%) in order. 3. The most common type by Lauge-Hansen classification was supination-external rotation type (37.4%). 4. In method of treatment, operative treatment was done in 72 cases and nonoperative in 59 cases. 5 The average duration of the cast immobilization in nonoperative treatment was 8 weeks and operative 7 weeks. 6. The better result was obtained by operative treatment than nonoperative one. 7. The most poor result was noticed in pronation-external rotation type according to Lauge-Hansen classification. 8. We agree that the accurate reduction of the lateral malleolus make the talus in good anatomic position in ankle joint. 9. We agree that Lauge-Hansen classification is useful in diagnosis and treatment of ankle fracture.

A Case of Dislocation of the Hamte Bone / 대한정형외과학회잡지

Dislocation of the hemate bone is very rare. There is no reported case in Korea. The mechanism of injury may be attributed to direct trauma. We have experiened a case of dislocation of the hamate bone, treated it by open reduction and internal fixation using two Kirschner wires. The result was satisfactory. A case of dislocation of the hamte bone is reported with brief review of literature.

Clinical Observation on Children's Fractures / 대한정형외과학회잡지

The present study is an observation of 678 cases of children's fractures; which was treated in the Dept. of Orthopedic Surgery, inchon Christian Hospital, for the past ten years, from 1968 to 1978. The peak age was in from 5 years to 6 years. The sex ratio was 2.9 male to 1 female. The ratio between the right and left extremity was nearly equal. The frequency of fracture of the upper extermity was silghtly dominant then lower extremity. The cause of fracture was fall down Injury in nealy 70% of all cases. The epiphyseal Injury was noted as 16.8% of total orthapedic cases. The most common type of Salter & Harris Classiflcation was type II or 56.1%. Mostly all of children's fractures were treated by closed method, and others were treated by open reduction. Complication Included 29 cases of changed carring angle 18 cases of traumatic arthritis and 8 cases of malunlted supracondylar fracture and 3 cases of postoperative Infections and 2 cases of radial nerve palsy and 3 cases of delayed ulnar nerve palsy of the elbow. In fractures of the femur, 3 cases of the peroneal nerve palsy and 2 cases of leg longth discrepancy was noted. Brief discussion and review of Iiterature is presented.

Fracture of the Coracoid Process Associated with Acromioclavicular Dislocation: A Case Report / 대한정형외과학회잡지

Fracture of the coracoid process are rare and those associating with a complete acromioclavlcular separation is even more rare. The mechanism of injury may be attributed to either direct or indirect trauma. Most coracoid fractures are minimally displaced because It is by maintained by the coracoclavicular ligament and coracoacromial ligaments. Usually good result is obtained In the coracoid fracture by non-operative treatment. On the other hand open reduction Is rarely Indicated. The case we are reporting was treated by open reduction and Internal fixation of the acromloclavicular joint using two Kirschner wires, and screw fixation was done for the fracture of the base of the coracoid process. Review of the literature ls also done.