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Biomedical subjects

R K Hong

Publications and source records attributed to R K Hong.

10 recordsLinked to original sources
PubMed2001

Effect of reverse curve mushroom archwire on lower incisors in adult patients: a prospective study.

This prospective clinical study was undertaken to analyze adult skeletodental changes induced by a reverse curve mushroom archwire during the initial stage of treatment. Lateral cephalograms from before treatment and immediately after bite opening were evaluated from 8 female adult patients who were undergoing lingual orthodontic treatment. Before treatment the patients had a mean overbite of 3.9 mm. Six linear and 5 angular measurements were selected for cephalometric analysis. The mean change in the cephalometric parameters was subjected to paired t-tests to determine whether the change was significant. There was a highly significant overbite reduction (-1.9 mm, P < .001) leaving a postintrusion overbite of 2.0 mm. The lower incisors were intruded 1.5 mm (P < .001) and the lower incisor edge was in an approximately stable sagittal position (L1 to NPg = -0.2 mm, NS). Some lower incisor proclination (L1 to MP = 1.2 degrees) was seen, which was not of significance. The mandibular molars were not significantly extruded. After bite opening the mandibular plane angle was not significantly altered. Consequently, the lower anterior face height was not significantly increased. The results of this study revealed that the use of reverse curve mushroom archwire is capable of intruding the lower incisors with minimal side effects on the posterior teeth.

Adult↗
PubMed1992

The effect of orthodontic retention on the mechanical properties of the periodontal ligament in the rat maxillary first molar.

The load-deformation curves obtained by extraction of the rat maxillary first molar from its socket in the dissected jaw were analyzed so that the effect of orthodontic retention on the mechanical properties of the periodontal ligament could be examined. An elastic band was inserted between the rat maxillary first and second molars for four days, and then the interdental space was filled with resin for four or eight days. The average interdental spaces between the teeth ranged from 315 to 398 microns during the experimental period. The maximum shear load, elastic stiffness, and failure energy in shear decreased markedly following application of an orthodontic force, but they increased gradually and reached control levels on the 8th day after the retention. Maximum shear deformation at maximum load was not significantly different between the experimental and control teeth during the experimental period. It is suggested that, following orthodontic tooth movement, occlusal function was restored after a relatively short retention period, as was the impaired mechanical strength of the periodontal ligament.

Alveolar Process↗
PubMed1992

A new design of internal fixation for scoliosis and its preliminary clinical application.

A new scoliotone composed of screw, socket, distraction rod, lateral mass and compression rod can produce free movement in three different planes and fix the vertebral column in three-dimensions. The instrument has a strong force of fixation, distraction, compression and anti-rotation and it can be locked in any degree angle. Preliminary clinical application in 10 cases showed that when the spinal curvature (Cobb's angle) was less than 50, the average correction rate of scoliosis was 78.2% and that of the hump was 90%; when Cobb's angle was within 50-100 degrees, the average curve correction was 68.2%, and the hump correction 87.7%; when Cobb's angle was 100 degrees, the average curve correction was 63.3%, and the hump correction 82%. The vertebral column needed no external fixation after the operation. Biomechanical characteristics of the vertebral pedicle, and the technical features are discussed.

Humans↗