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Biomedical subjects

O Slagsvold

Publications and source records attributed to O Slagsvold.

8 recordsLinked to original sources

Applicability of autotransplantation in cases of missing upper anterior teeth.

No immunologic problems are involved in autotransplantation, as they are in allotransplantation. One is justified in stating that the prognosis for autotransplantation of teeth is favorable, at least in young persons. In this report six cases are presented to demonstrate that autotransplantation can contribute to more satisfactory solutions to the problem of missing anterior teeth than can otherwise be achieved. It is difficult to form general rules regarding the indications for autotransplantation in such cases. Each case must be assessed on its own premises: the substitution need, the availability of a transplant, the long-term prognosis, and the advantages and disadvantages of a solution with autotransplantation versus solutions without autotransplantation. It should be admitted that the applicability of autotransplantation is limited. However, the therapist who realizes that the applicability in young patients is primarily a question of the availability of transplants may find that this is greater than he has previously realized.

Anodontia

Indications for autotransplantation in cases of missing premolars.

The postoperative behavior of premolars transplanted before completion of root formation and the long-term prognosis for such teeth have recently been studied. After postoperative observation periods ranging between 3 years 4 months and 13 years 9 months, all of the thirty-four teeth in question were found to still be in place. Root formation had continued, supporting tissues had developed, and the teeth had erupted. In most instances they had functioned normally without giving rise to problems of any kind. Their status during the re-examination implied that most of them would function normally for many years to come, perhaps for a lifetime. Autotransplantation of missing premolars in many cases is the only alternative to prosthetic substitution, and it is our method of preference. However, substitution by autotransplantation cannot be applied unless a suitable transplant is available. Any premolar destined to be extracted for orthodontic reasons is a possible transplant. In young patients it is also a suitable one. In orthodontic extraction cases, therefore, suitable transplants are usually available. In nonextraction cases, none is available unless teeth in other dental arch quadrants are "sacrificed." In the present report six cases are presented as examples of solutions to the problem of missing premolars by autotransplantation. The main combinations of missing teeth and types of malocclusion in which premolars extracted for orthodontic reasons can advantageously be used as substitutes for other premolars are defined. Also, the justification for "sacrificing" a premolar in one quadrant to the advantage of another quadrant is discussed.

Adolescent

Gonial angle distortion in lateral head films: a methodologic study.

The distortion of the gonial angle in lateral roentgenographic head films was studied in skull material. The left and the right gonial angles were determined craniometrically and roentgenocephalometrically, and the observations were compared. Mean difference of 8.48 degrees and 5.15 degrees between the roentgenocephalometric and the craniometric registrations were found for the side closer to the film and the side farther away from it, respectively. For the intermediate gonial angle, the difference was 6.65 degrees. The differences were all statistically significant. It was demonstrated that they were mainly attributable to a systematic method error in the roentgenocephalometric method, involving a magnification of the gonial angles. The magnification was significantly larger on the side closer to the film than on the side farther away from it. A pronounced individual variation in gonial angle distortion was observed. For intermediate gonial angle it ranged between magnifications of 1.17 degrees and 17.54 degrees. The distortion is closely associated with the form of the mandible. It is largest in mandibles with a pronounced divergence of the two halves of the corpus and a pronounced upward convergence of the rami. It is smallest in mandibles with a modest divergence of the two halves of the corpus and a pronounced upward divergence of the rami. By some very special combinations of corpus divergence and ramus inclination, a correct reproduction may be obtained. No such cases were found in the sample studied, but there can hardly be any doubt that they exist. There is an association between corpus divergence and ramus inclination. Maximum magnifying effect of the forward-extending leg tends to coincide with the maximum magnifying effect of the upward-extending leg. Conversely, minimum magnifying effect of the forward-extending leg tends to coincide with a dimishing effect of the upward-extending leg. This is the clue to an understanding of the great individual variation in gonial angle distortion. Generally speaking, lateral head films do not permit reliable registrations of the gonial angle. At present no method is available for an exact assessment of the distortion in head films of the single living person.

Adult

Growth in width of the frontal bones after fusion of the metopic suture.

Rat frontal bones reportedly exhibit lateral surface growth many weeks after fusion of the frontal suture. This is histologically confirmed in the present study. The mean width of the cranial vault at the postorbital constriction increased by 10% between the age of 30 and 58 days. The increase must be ascribed to periosteal growth, as the lateral, external surfaces exhibited active growth. External apposition without concomittant internal resorption causes an increase in bone thickness. The cells on the internal surfaces were in a state of rest. The study was based on a limited material; therefore, definite conclusions cannot be drawn.

Animals