Biomedical subjects
Publications and source records attributed to R L Christiansen.
This article concerns one of the major problems of all implants: the risk for latent potential infections. A case report involving latent infection of a mandibular implant is presented.
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This article describes two cases of condylar penetration into the middle cranial fossa in which a similar surgical procedure is used, namely, a rib graft for closure of the fossa. The rib graft, being an autogenous substance, does not present the problems associated with alloplastic materials. If care is taken not to contaminate the graft, and if the bone used has adequate thickness to prevent penetration and resorption, the graft will prove a superior option to repair damage in the middle cranial fossa.
A computerized craniofacial patient record reinforces the link between clinical research and the treatment process. The availability of microcomputers and appropriate software has made it feasible for most craniofacial groups to organize patient data for easy retrieval and analysis. Selection of the computer system and programs follows careful planning and systematic delineation of the desired functions of the system. An example of a working computerized craniofacial patient record system is described.
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A skull was described possessing posterior cranial base defect and resultant asymmetric growth of this structure. It was hypothesized that compensatory restraining influences of surrounding soft tissues prevented a more severe facial malformation from occurring.
A specially-designed force transducer was used to measure lateral resting-tongue pressure in 23 subjects. Seventeen subjects had normal occlusion and six had dental open-bite conditions. Three sensing tips with different contact areas were used to study the relationship between sensor area and measured force. The average force of the resting tongue was 0.8 g when measured with a 4.9 mm diameter sensor (pressure = 0.039 g/mm2). When the size of the sensor tip was increased, the force of the tongue increased in a nonlinear manner. Controlled incremental lingual constrictions of 6 mm resulted in an average increase in lingual force of 230 percent. The mean rate of change, measured in deflection gradient, was 0.34 g/mm. The mean stiffness of the lingual musculature was 2.30 g/mm. A correlation of r = --0.4 was found between resting-tongue pressure and mandibular intercanine width.
To assess the wide clinical ramifications of control of craniofacial morphogenesis, a State-of-the-Art Workshop was conducted by the National Institute of Dental Research at the initiative of Richard L. Christiansen, Chief of the Craniofacial Anomalies Program. In conjunction with the authors listed above, the format for the workshop was developed and participants were selected. The workshop was designed to provide an in-depth review of present knowledge and to identify future goals and directions for research on guiding, altering, and thus controlling growth and development of the cranofacial skeleton. The agenda for discussion ranged from molecular biology to clinical arts such as orthopedics and surgery. It was evident during the workshop that the mechanisms and procedures for controlling craniofacial morphogenesis must be derived from many biologic, physical, and clinical fields of knowledge. It is hoped that there will evolve an interdisciplinary clinical art which is aimed at preventing and correcting craniofacial deformities. Substantial biologic information has already been accumulated on the craniofacial skeleton. The clinical art of correcting malocclusion through mechanical forces is now applicable to the entire skull. The outstanding technical accomplishments of radical surgery in the correction of congenital craniofacial anomalies show that the needed surgical skills are now available. When these resources are combined, an area of knowledge and a clinical discipline which might be called "orthocephalics" is already identifiable. The workshop was held at the National Institutes of Health in Bethesda, Maryland, on Feb. 12 and 13, 1974. The ideas exchanged were integrated and summarized by the planning committee to produce this report.
Dental pulpal and mandibular marrow vascular pressures were studied with a tonometric method under conditions of autoperfusion and step flow controlled perfusion. The tonometric pulpal and marrow pressures averaged 17 +/- 5 mm Hg and 20 +/- 6 mm Hg, respectively. The venous end pressure was 16 +/- 8 mm Hg at a perfusion pressure of 156 +/- 28 mm Hg. The tonometric pulpal pressures were lower and were less variable than the comparable canulation pulpal pressures.
Specific anomalies of the skull in eight family members affected with Saethre-Chotzen syndrome were documented by cephalometric analysis of standardized skull radiographs. The most severe deviations included reduced length and abnormal position of the posterior cranial base, low position of the sella turcica, reduced mandibular ramus length, steep mandibular plane angle, and, in adults, reduced facial depth. A feature of the syndrome may be the absence or reduced size of cranial sinuses.
The following report on assessing research on variation in dental occlusion was based in part on a workshop conducted by the National Institute of Dental Research at the initiative of Richard L. Christiansen, Chief, Craniofacial Anomalies Program. The meeting was planned and developed by Robert J. Isaacson, Chairman, Touro M. Graber, Richard A. Riedel, and Richard L. Christiansen. This report is designed to provide a review of the achievements, directions, and needs of research concerning variations in dental occlusion. The workshop was held at the National Institutes of Health, Bethesda, Maryland, on Nov 22 and 23, 1972. The material presented by the workshop participants has been summarized and incorporated in this report. The subject of research related to the field of malocclusion was discussed in an article published in the American Journal of Orthodontics in January, 1971.
Three NIDR-sponsored workshops were conducted with the goal of identifying research needs in treatment and basic sciences relating to a group of severe craniofacial anomalies that are now correctable by new radical surgical procedures. Experts in the fields of developmental biology, neurosurgery and reconstructive craniofacial surgery discussed areas of investigation dealing with etiology, prevention and treatment that are most likely to result in clincally-useful information. In addition the establishment of craniofacial anomalies centers for data collection, treatment and research was examined.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.