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Biomedical subjects

J Caton

Publications and source records attributed to J Caton.

At least 55 records · Page 3Linked to original sources
PubMed1985

[Long-term course of lumbar curvature following Harrington instrumentation for thoracic or double major idiopathic scoliosis].

A long-term follow-up study has been made of 276 patients with thoracic or double major idiopathic curves treated by Harrington rodding between 1963 and 1971. 82 patients were able to be followed up to the present date, including 24 double major idiopathic curves and 58 thoracic or thoracolumbar curves. The average follow-up was 15 years with a maximum of 20 years. There were 71 female and 11 male patients. It was concluded that the lumbar curve associated with a thoracic or thoraco-lumbar curve lost about 9.9 degrees when the lower point of insertion of the rod was higher than L3. When it was at L3 or L4 loss of correction was only 3.6 degrees. During the same period the loss of correction of the main grafted curve was 13.6 degrees. In double major curves, the best results were obtained when the lumbar curve was completely or almost completely fused, with an average correction of 17.2 degrees. The results were good when the fixation extended to the apex of the lumbar curve, with an average correction of 11.6 degrees and was moderate when it extended to a higher level with an average correction of 10.9 degrees. It is concluded that in almost all cases, instrumentation needs to be extended to a low level at L3 or L4 to provide greater stability. A study on all 276 cases showed that the morphological adaptation beneath the grafts was satisfactory and long lasting. When the instrumentation stopped at the level of T12, L1 or L2 there was a danger of the development of secondary lumbar kyphosis. Low back pain was not made worse in any cases of low lumbar fixation.

Adolescent↗
PubMed1984

Histologic comparisons of interproximal gingival tissues related to the presence or absence of bleeding.

Interproximal gingival tissues were compared histologically relative to the presence or absence of bleeding after stimulation with a wooden interdental cleaner. Fifteen bleeding and 15 nonbleeding interproximal gingival biopsy specimens were obtained from 30 patients and processed for light microscopic evaluation. Morphometric analysis of tissue components revealed that bleeding areas had a significantly greater per cent of inflamed connective tissue. The inflammatory lesion in the bleeding specimens was primarily in the midinterproximal area. From a diagnostic standpoint, this information provides a rationale for the use of bleeding to detect inflammatory lesions in the midinterproximal region.

Adult↗
PubMed1984

Periodontal response after tooth movement into intrabony defects.

The present study was undertaken since conflicting evidence exists regarding the effect of such tooth movement on levels of connective tissue attachment. Localized intrabony pockets were produced around isolated incisors in four rhesus monkeys. The root surfaces were planned to the level of the bone at the base of the angular bony defects. An oral hygiene regime was begun and continued for the remainder of the study. The experimental teeth were moved orthodontically into, and through, the original area of the intrabony defect. Two months after cessation of active tooth movement, block specimens were removed for histologic analysis. Control specimens comprised those teeth with induced periodontal defects, but without tooth movement. In specimens not subjected to tooth movement, angular bony defects were present and epithelium lined the root surface to the apical extent of instrumentation. The alveolar bone adjacent to the orthodontically moved teeth no longer had angular defect morphology. On the pressure side, epithelium lined the root surface, was interposed between root surface and bone and terminated at the apical limit of root instrumentation. On the tension side, the crest of the bone was located apical to the level of root planing, and epithelium lined the instrumented portion of the root surface. It was concluded that orthodontic tooth movement into intrabony periodontal defects was without effect upon the levels of connective tissue attachment.

Alveolar Process↗
PubMed1984

[Importance of the E. Luque technic in the surgery of major spondylolisthesis in children].

Following a brief summary of results of surgery of major spondylolisthesis of children using Harrington's technique, the outcome in 15 cases operated upon between 1967 and 1983 is discussed. Satisfactory short-term results (reduction perfect in 40% and fair in 60%) were not maintained and a relapse of sliding occurred in 50% at a later stage. In order to improve long-term stability. Harrington's classical procedure was combined with Luque's technique with binding of posterior arches of L3 and L4 to metallic spars in major L5-S1 spondylolisthesis. Two adolescents with very disabling L4-L5 spondylolisthesis were operated upon by Luque's original method combining partial resection of supra- and sub-jacent articular surfaces and isthmic reconstruction by grafts with excellent immediate results. This method is also discussed.

Adolescent↗
PubMed1983

A periodontal attachment mechanism without alveolar bone. Case report.

A 22-year-old black male was referred for periodontal therapy because of radiographic evidence of advanced bone loss associated with the posterior teeth. Clinical examination revealed gingivitis, normal sulcus depths, and minimal loss of clinical attachment. Complete blood counts, serum chemistry, and neutrophil function were within normal limits. Histological, histochemical and ultrastructural analysis of an extracted tooth revealed no loss of attachment; large areas of the cementum were collagen-poor and, ultrastructurally, resembled afibrillar cementum. It is proposed that the periodontal attachment mechanism present in this case was associated with a localized failure in normal periodontal development.

Adult↗
PubMed1982

Factors influencing periodontal repair and regeneration.

The purpose of the present study was to evaluate independently the regeneration capacity of a reduced periodontium, and the potential for new connective tissue attachment to a periodontally exposed root surface. A reduced periodontium was produced around a maxillary central incisor in two Rhesus monkeys using orthodontic elastics. The regeneration capacity of this reduced peridontium was investigated by extracting the periodontally involved tooth and transplanting into the socket the contralateral incisor which had a normal periodontium. The potential for new connective tissue attachment to a periodontally exposed root surface was evaluated by transplanting an exposed root into a normal periodontium. These exposed roots were the incisors extracted from the reduced peridontium. Control specimens were obtained by extracting and reimplanting or transplanting the remaining maxillary and mandibular incisors. Forty days after the experimental procedures, block sections were removed and prepared for histologic analysis. The exposed root surface that had been put into the normal periodontium was lined with epithelium interposed between root surface and alveolar bone. The normal root surface that had been put into the reduced periodontium had connective tissue reattachment in the periodontal ligament and supracrestal regions. Areas of ankylosis and root resorption were present in all specimens, as was new cementum in the periodontal ligament region. The results indicated that root surface alterations, rather than presence of a reduced periodontium, inhibited new connective tissue attachment.

Animals↗
PubMed1982

Initial healing of periodontal pockets after a single episode of root planing monitored by controlled probing forces.

THE PURPOSE OF the present study was to evaluate, using controlled probing forces, the response of periodontal pockets to a single episode of root planing. The clinical characteristics of 128 pockets (3-7 mm depth) distributed in ten subjects, were monitored immediately before and 1, 2, 3, and 4 weeks after a single episode of subgingival root planing. The clinical parameters measured were: pocket depth and bleeding after probing with 15 gm, 25 gm, 50 gm of controlled probing force and manual probing, gingival margin location, loss of attachment, gingival and plaque indices. Oral hygiene instruction and supragingival prophylaxis were given at each time point. An average aggregated score for each subject for each parameter was calculated at each time point. A repeated measure all-within analysis of variance was done, and the Tukey multiple range test was used to assess the significance of differences among and between the means. Plaque and gingival indices decreased significantly after 1 week. Significant pocket depth reduction (initial) occurred 1 week after root planing, and reduced further (secondary) at 3 weeks. Initial pocket reduction was associated with significant gingival recession, whereas secondary pocket reduction was associated with significant gain of clinical attachment. Bleeding upon probing was virtually absent after 3 weeks. All probing changes were detected more consistently using controlled insertion pressures. It was concluded that substantial reduction in pocket depth occurs within 3 weeks after a single episode of root planing owing to initial gingival recession and secondary gain in clinical attachment.

Adult↗
PubMed1982

Maintenance of healed periodontal pockets after a single episode of root planing.

The present study evaluated the clinical stability of healed periodontal pockets over a 3 month time period to determine whether this time interval is appropriate for periodontal maintenance therapy. The clinical characteristics of 128 pockets (3-7 mm depth) distributed in 10 patients, were monitored immediately before and 4, 8 and 16 weeks after a single episode of subgingival root planing. The clinical parameters measured were: pocket depth and bleeding after probing with 15, 25 and 50 gm and manual probing, gingival margin location, clinical attachment level, and gingival and plaque indices. Oral hygiene instruction and supragingival cleaning were given at each time point. An average aggregated score for each subject and for each parameter was calculated at each time point. A repeated measure all within analysis of variance was done, and the Tukey multiple range test was used to assess the significance of differences among and between the means. The significant decreases in plaque, gingival and bleeding indices, and pocket depth as well as the significant gingival recession and gain of clinical attachment which were present at the 4 week point were maintained at 8 and 16 weeks after root planing. It was concluded that the favorable clinical changes which occur in periodontal pockets within 1 month after a single episode of subgingival root planing combined with improved oral hygiene can be maintained for an additional 3 month time period.

Dental Plaque↗
PubMed1982

[Patella infera. Apropos of 128 cases].

A low patella is frequently a complication of a lesion of the knee but it can also present secondary symptoms of its own. The authors describe an original method for assessment of the vertical level of the patella. They have tried to establish a relationship between the low situation of the patella and pain of a certain type associated with limited flexion of the knee. Physiopathological and biomechanical evidence is taken into account. In most instances, a low patella is secondary either to a mechanical cause, natural or iatrogenic, or to an inflammatory cause such as algodystrophia. 29 patients out of 128 observed cases have been operated on. 17 of these were due to excessive transplantation of the anterior tibial tubercle. In most of the cases the tibial tubercle was transplanted upwards in association with a joint release. In only 3 cases a patellectomy was done. The results were excellent or good in half of the cases and unsatisfactory in the other half.

Adult↗
PubMed1981

Depth of periodontal probe penetration related to clinical and histologic signs of gingival inflammation.

The purpose of this study was to determine if the depth of periodontal probe penetration into the gingival sulcus was related to bleeding after probing with a standardized force, visual signs of gingival inflammation, and histological parameters of gingival inflammation. Sixty midfacial gingival sites in 26 persons were evaluated for presence or absence of visible inflammation and bleeding after probing using a controlled insertion pressure of 25 gm. In order to delineate the area for histologic analysis, a reference incision was made on the facial surface of the gingiva which corresponded to the depth and mesio-distal extent of the area probed and evaluated for visual signs of inflammation. Gingival biopsy specimens were histometrically analyzed to determine the depth of probe penetration and percentage of inflamed connective tissue. Statistical analysis of the data demonstrated that probe penetration was significantly greater in the presence of visible inflammation, but not with bleeding after probing. Furthermore, only a weak correlation existed between depth of probe penetration and percentage of inflamed connective tissue adjacent to the area probed.

Adult↗
PubMed1981

Relationships between epithelium and connective tissue in inflamed gingiva.

Since chronic inflammation has been associated with degenerative and proliferative responses in connective tissue and epithelium, it was decided to investigate quantitatively the proportions of epithelium and connective tissue in inflamed gingiva. Forty-five midfacial gingival sites were assessed prior to biopsy for the presence or absence of bleeding after probing using a controlled insertion force fo 25 g. In order to delineate the corresponding area for histologic analysis, a reference incision was made on the facial surface of the gingiva which demarcated the depth and mesio-distal extent of the area probed. Step-serial bucco-lingual sections were morphometrically analyzed to determine the percentages of epithelium, inflamed, and noninflamed connective tissues coronal to the reference incision. The data was compared with respect to the presence or absence of bleeding after probing. Specimens which bled after probing had significantly less epithelium and more connective tissue. The increase in overall connective tissue was due to a significant increase in the inflamed component, and it appeared that the decrease in epithelium corresponded to the increase in inflamed connective tissue. The findings of diminished epithelium overlying inflamed connective tissue reinforces the concept that connective tissue status is important for determining structure and function of epithelium.

Adult↗
PubMed1981

Histometric evaluation of periodontal surgery. III. The effect of bone resection on the connective tissue attachment level.

The purpose of this study was to evaluate the effect of surgical elimination of the osseous walls of angular bony defects on the connective tissue attachment and alveolar bone levels. Using a Rhesus monkey model, 36 periodontal pockets in four animals were operated on while the contralateral pockets served as unoperated controls. Plaque control was maintained until the animals were killed 1 year after surgery. Following routine processing, the interdental tissues were analyzed histometrically. Comparing measurements of surgically treated and untreated sites, resection of the osseous walls of interdentally located angular bony defects caused not only a reduction in the height of the alveolar bone but also a significant loss of connective tissue attachment. The procedure also resulted in the elimination of angular bony defects, intrabony pockets, and in addition, reduced the height of the interdental soft tissue.

Alveolar Process↗
PubMed1981

Histologic characteristics associated with bleeding after probing and visual signs of inflammation.

This study was designed to characterize histologically the gingival lesion associated with visual signs of inflammation and bleeding after probing. Sixty midfacial gingival sites in 26 persons were evaluated for visual presence of absence of inflammation and bleeding after probing using a controlled insertion pressure of 25 gm. In order to delineate the area for histologic analysis, a reference incision was made on the facial surface of the gingiva which corresponded to the depth and mesio-distal extent of the area probed and evaluated for signs of inflammation. Gingival biopsy specimens were morphometrically analyzed to determine the percentages of cell rich--collagen poor connective tissue and blood vessel lumens. Histometric data were grouped and compared with respect to the presence or absence of inflammation and bleeding. Specimens associated visually with inflammation had significantly greater percentages of both cell rich--collagen poor connective tissue and blood vessel lumens. Bleeding upon probing was associated with a significantly greater percentage of cell rich--collagen poor connective tissue without an increase of blood vessel lumens. It was concluded that both observed signs of inflammation and bleeding after probing can be used to detect inflammatory lesions in the gingiva. However, in areas inaccessible for evaluation of inflammation, bleeding determinations using controlled insertion pressures provided an objective diagnostic method for detecting the presence of an inflammatory lesion.

Adult↗
PubMed1981

[Ligamentous tears associated with tibial condylar fractures (author's transl)].

In fractures of the tibial condyles, associated ligamentous tears may be discovered by the presence of additional bone fragments, by stress radiographs or by tomography. Two types of lesion were found among the 25 cases treated by the authors. In the first group there was a uni-condylar fracture associated with a tear of the medial or lateral ligament. In the second group, there was a uni-condylar fracture associated with a fracture of the tibial spine. After a review of their results, the authors consider that ligamentous lesion should be treated surgically as well as the bony lesions which must be repaired first. Post-operative immobilisation was continued for one month followed by rehabilitation. An arthrolysis may be done five months later if necessary.

Humans↗
PubMed1980

Histometric evaluation of periodontal surgery. I. The modified Widman flap procedure.

The present investigation was performed in the Rhesus monkey to determine the effect of the modified Widman flap procedure on the level of the connective tissue attachment and supporting alveolar bone. Two adult male Rhesus monkeys were used. Eighteen contralateral pairs of periodontal pockets were produced in a standardized manner. Surgical treatment of the pockets was performed around experimental teeth and the contralateral teeth were used as the unoperated controls. Twelve months following treatment the animals were sacrificed and histological sections obtained. Using the cemento-enamel junction (CEJ) as a fixed reference point, linear measurements along the root surface were made to the most apical cells of the junctional epithelium (JE), to the crest of the interproximal alveolar bone (CR), and to the apical extent of angular bony defects (AAD). These measurements from operated and unoperated pockets were then compared. The data revealed that treatment of periodontal pockets using the modified Widman flap procedure produced no gain in connective tissue attachment and no increase in crestal bone height. In angular bony defects a certain degree "bone fill" was noted. This bone repair was never accompanied by new connective tissue attachment.

Alveolar Process↗