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Biomedical subjects

J Bardach

Publications and source records attributed to J Bardach.

At least 37 records · Page 2Linked to original sources

Does interference with mucoperiosteum and palatal bone affect craniofacial growth? An experimental study in beagles.

This study was designed to assess the effects of raising mucoperiosteal flaps and exposing palatal bone at the time of palatoplasty. Using 62 beagle puppies as subjects, we tested the hypothesis that raising mucoperiosteal flaps does not interfere with craniofacial growth. We further hypothesized that the size of the area of bone exposed following palatoplasty does affect subsequent craniofacial growth. The animals were divided into four groups: two control groups (unoperated and unrepaired) and two experimental groups. In the first experimental group, two-flap palatoplasty was used to close the surgically induced palatal defect, leaving narrow strips (0 to 2.5 mm) of bone exposed lateral to the flaps. In the second group, one flap was raised to close the defect, leaving a wide area (5 to 6 mm) of palatal bone exposed on one side. Thirty-four direct craniometric measurements were analyzed. Animals that had elevation of both mucoperiosteal flaps with narrow strips of denuded bone on both sides had less severe craniofacial growth aberrations than those in which the defect was left unrepaired or was repaired with one mucoperiosteal flap leaving a wider area of bare bone exposed. These findings suggest that raising mucoperiosteal flaps is less detrimental to craniofacial growth than leaving large areas of exposed palatal bone.

Analysis of Variance↗

Association of genetic variation of the transforming growth factor-alpha gene with cleft lip and palate.

Complex segregation analysis of pedigrees having nonsyndromic cleft lip with or without cleft palate (CL/P) (Chung et al. 1986; Marazita et al. 1986) has shown that a major-locus model best explains the observed recurrence of CL/P in Caucasian families. To identify this major gene, we compared the frequencies of 12 RFLPs at five loci-epidermal growth factor, transforming growth factor-alpha, epidermal growth factor receptor, glucocorticoid receptor, and estrogen receptor-in both a group of 80 subjects with nonsyndromic CL/P and 102 controls. These candidate genes were selected because studies in rodents had suggested their possible involvement in palatogenesis. A significant association was observed between two RFLPs at the transforming-growth-factor-alpha (TGFA) locus and the occurrence of clefting (P = .0047 and P = .0052). This suggests that either the TGFA gene itself or DNA sequences in an adjacent region contribute to the development of a portion of cases of CL/P in humans and provides an opportunity to begin to examine the molecular events underlying lip and palate formation.

Adolescent↗

Cleft lip and palate and related disorders: issues for future research of high priority.

On October 14 to 17, 1987, a meeting entitled "State of the Art Conference: Multidisciplinary Management of Cleft Lip and Palate" was held in Iowa City. The major purpose of the conference was to review the available knowledge concerning management of unilateral cleft lip and palate from the perspectives of surgery, speech-language pathology, and orthodontics. The closing feature of the conference was the identification of issues for future research. Participants identified issues of high priority that were then discussed by the entire conference faculty. This paper reports the summary of that discussion and the recommendations of the Conference.

Cleft Lip↗

A comparative study of the skin envelope of the unilateral cleft lip nose subsequent to rotation-advancement and triangular flap lip repairs.

The secondary nasal skin envelope asymmetries were studied after unilateral cleft lip repair using the original (obsolete) rotation-advancement (Millard I) and the triangular flap techniques (Bardach's modification). Secondary correction of the nasal deformity was not performed in either group. Our findings indicated that in both groups, vertical asymmetries of the nasal skin envelope were similar. The alar dome on the cleft side was depressed, the columella was shorter on the cleft side, and there was hooding at the nostril apex. The principal difference between the two lip repairs was observed in the horizontal dimension of the nasal skin envelope. The position of the alar base was more normal following the Millard I repair, while the triangular flap repair left the alar base laterally displaced. When considered together with flattening of the cleft alar dome, a horizontal skin-envelope deficiency from middome to lateral alar crease was produced in the Millard I group. More lateral positioning of the alar base after the triangular flap technique minimized this horizontal skin deficiency. The triangular flap technique produced a secondary nasal deformity that looked worse but was easier to correct. The clinical implications of these findings are discussed.

Adolescent↗

Irradiated homologous cartilage grafts. Long-term results.

The use of irradiated homologous cartilage for the restoration of facial contour defects remains a controversial issue in reconstructive surgery. Both favorable and unfavorable reports can be found in the literature. Some basic research concerning the rate and mechanism of resorption has been completed but has failed to resolve the issue of the usefulness of this material in day-to-day practice. One frequently cited reference concerning the use of irradiated homologous cartilage in reconstructive surgery was coauthored by two of the present investigators ten years ago. In an effort to place this study in a long-term perspective, we examined 42 of the original 107 patients who formed the initial population base. Sixty-two of the original 145 irradiated homologous cartilage grafts have been followed up for an average of nine years, with an average resorption rate of approximately 75%. Eighteen of 24 grafts followed up from 11 to 16 years completely resorbed. In spite of complete graft resorption, some patients have maintained satisfactory facial contour with fibrous tissue replacement of the cartilage.

Absorption↗

Basal cell carcinoma arising in a sebaceous nevus during childhood.

It is uncommon for malignancy to develop in a sebaceous nevus before puberty. We report a case of basal cell carcinoma arising in a sebaceous nevus during childhood in a normal-appearing lesion. Periodic evaluation to detect malignant degeneration is recommended for children even if removal is encouraged at a future date.

Age Factors↗

The influence of lip repair with and without soft-tissue undermining on facial growth in beagles.

The present study was designed to test the hypothesis that undermining of the soft tissues on the surface of the maxilla at the time of lip repair in unilateral cleft lip, alveolus, and palate results in more severe craniofacial growth aberrations than lip repair alone. Sixty-seven purebred beagles were used in this experiment. The animals were divided into four groups: two control groups (unoperated and unrepaired) and two experimental groups (lip repair without undermining and lip repair with undermining). Lip pressures were monitored in all groups. Significantly higher lip pressures were observed in animals with soft-tissue undermining. Cephalometric measurements were analyzed using univariate and multivariate techniques. The results of this study indicate that lip repair performed with soft-tissue undermining results in more severe craniofacial growth aberrations than lip repair performed alone.

Analysis of Variance↗

Role of animal models in experimental studies of craniofacial growth following cleft lip and palate repair.

The present study was designed to examine the role of the animal model on investigations of craniofacial growth. Identical experimental protocols were followed using 6-week-old rabbits and 8-week-old beagles. Three groups were used for each species, two control groups and one experimental group. The groups within each experimental model were compared for lip pressure, occlusion, and cephalometrics. Statistical analyses including analyses of correlations were used to evaluate dimensional craniofacial relations. The results of this study revealed that dimensional relations were significantly different in rabbits and beagles despite the similarities observed in overall craniofacial growth aberrations. Analysis of the results does not allow strong conclusions about which animal model (rabbits or beagles) is more appropriate for studying craniofacial growth.

Animals↗

Simultaneous cleft lip and palate repair: an experimental study in beagles.

This study was designed to test the hypothesis that simultaneous lip and palate repair results in more severe craniofacial growth aberrations than lip repair or palate repair performed separately. Seventy-six purebred beagles were divided into five groups. Two of these groups were controls (unoperated and unrepaired animals); the three remaining groups were experimental (in one group only the lip was repaired, in another only the palate was repaired, and in the last the lip and palate were repaired simultaneously). Cephalometric measurements were analyzed using univariate and multivariate statistical techniques. In multivariate analysis, stepwise multiple regression and discrimination were applied to precisely assess the effects of the various surgical procedures. The results of this study indicate that simultaneous lip and palate repair results in more severe craniofacial growth aberrations than lip repair or palate repair performed separately.

Animals↗

Implantation of human keloid into athymic mice.

In the interest of developing an animal model for keloids, human keloid dermis was implanted in the subcutaneous tissues of athymic (nude) mice. Subsequent growth resulted in a lesion with histology similar to the original keloid. Fibroblasts were cultured from keloid dermis. When the fibroblasts alone were implanted in the subcutaneous tissues of nude mice, growth of a visible lesion was again produced. The fibroblasts had proliferated and deposited collagen in an abnormal fashion with the histology resembling the parent keloid. Further research could develop this into a reliable animal model to allow in vivo experimentation.

Adult↗

Enhancement of tissue expansion by anticontractile agents.

To evaluate the effect of anticontractile agents on the rate of tissue expansion, guinea pig back skin was expanded while being treated with various anticontractile agents. Expansion was carried out using standard percutaneous inflatable skin expanders modified by the addition of a catheter to deliver the anticontractile agents papaverine or cytochalasin D. Expansion proceeded for 25 days with one or other of the substances being infused through the catheter; saline was used in a separate control group. Measurements of the rate and extent of expansion showed that there was a statistically significant increase in these parameters for the experimental groups as compared with saline controls. Histologic examination of the expanded tissue suggests that the cellular basis for this phenomenon may involve the relaxation or inactivation of contractile fibroblasts in the fibrous capsule surrounding the expander.

Animals↗

Late results of multidisciplinary management of unilateral cleft lip and palate.

A model was designed for evaluating protocol and management strategies in the multidisciplinary approach to cleft lip and palate treatment. The treatment history and present status of 45 patients 14 to 22 years of age were evaluated by a plastic surgeon, orthodontist, and speech pathologist. Results indicated that only about half of these patients had completed treatment by one of the specialties by the time they were 14 years or older. Even more surprisingly, only 7 patients (16%) had completed treatment by all three specialties by this age. Factors that may contribute to this low percentage of completed treatments are discussed.

Adolescent↗