• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.278-288
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• 1998

An efficient and useful method to improve the local stress field in a displacement-formulated finite element solution has been proposed using the theory of conjugate approximations for a stress field and the Loubignac's iterative method for a displacement field. Validity of the proposed method has been tested through three test examples, to improve the stress field and displacement field in the whole domain and the local regions. As a result of analysis on the test examples, it is found that the stress field in the local regions are approximated to those in the whole domain within a few iterations which have satisfied the original finite element equilibrium equation. In addition, it is found that the local stress field are by far better approximated to the exact stress field than the displacement-based stress field with the reduction of the finite-element mesh-size.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.345-350
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• 2008

In children with Class III malocclusion, it is important to identify whether the etiology is functional, dental, skeletal. FR-III developed by Rolf Frankel in 1970, has been used during deciduous, mixed, and early permanent dentition to correct class III malocclusion characterized by maxillary skeletal retrusion. According Frankel, the vestibular shields and upper labial pads act to counteract the forces of the surrounding musculature that restrict forward maxillary development and cause a retrusion in maxillary tooth position. This can achieve favorable developments with the basal bone, teeth and alveolar bone. We report FR-III that can be applicated in cases of early mixed dentition with mild maxillary deficiency and deepbite before the eruption of permanent maxillary incisor.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.108-113
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• 2009

The functional regulator(FR) appliances act to remove the restrictive forces that prevent the normal maturation of the maxilla and mandible. FR appliances are different from other functional jaw orthopedic appliances(e.g., the twin block, bionator, and activator). $Fr{\ddot{a}}nkel$ has based his treatment philosophy on the concept that the capacity to regulate growth residues in the soft tissue environment, and that adequate space must be available for the proper development of the hard tissue. In class II malocclusion with mandibular retrusion, FR-II treatment is not only the change in the postural position of mandible, but also expansion of the dental arches. By balancing the neuromuscular environment, not only can severe malocclusions be treated successfully, but also the tendency toward relapse is minimized because the neural and soft tissue factors associated with the skeletal malocclusion have been addressed as well. We report cases using by FR-II that is applicated in cases of Class II malocclusion without fixed appliance, only FR-II and space supervision.