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Biomedical subjects

J Bardach

Publications and source records attributed to J Bardach.

At least 19 recordsLinked to original sources
PubMed1992

Demineralized perforated bone implants in craniofacial surgery.

Between July 1990 and September 1991, demineralized perforated allogeneic bone implants (Pacific Coast Tissue Bank, Los Angeles, CA) were placed in 72 patients. Because many patients received more than one implant, a total of 248 implants were used in 80 procedures. The technology of processing demineralized bone implants is described in detail. All patients were operated on by one surgeon (K.E.S.) at the Humana Craniofacial Institute in Dallas, Texas. Forty-one patients had craniofacial deformities, 16 had secondary deformities following cleft lip and palate repair, 8 had bony defects following removal of tumors, and 10 had various skeletal deformities following trauma. Of the 72 patients, 6 had two surgical procedures during which additional implants were inserted. Implants placed in the cranial vault and the maxillary complex, including alveolar grafts, were inlay grafts, whereas implants placed in the orbital, nasal, paranasal, temporal, and malar areas were onlay grafts used for contouring, augmentation, or both. Complications were limited to delayed wound healing in 6 patients. According to our observations, demineralized perforated bone implants represent an encouraging alternative to autogenous bone grafting. Further clinical and experimental studies are necessary to obtain more information about this material.

Adolescent↗
PubMed1992

Results of multidisciplinary management of bilateral cleft lip and palate at the Iowa Cleft Palate Center.

Bilateral cleft of the lip and palate is by many standards the most complex and severe form of the defect. The complexity and severity of the defect require an unusual degree of cooperation among all specialists and especially between the surgeon and the orthodontist. There are no published findings that we know about in which comprehensive data from a number of disciplines are reported for the same group of bilateral cleft patients. Fifty randomly selected patients with bilateral complete clefts were examined by the Iowa team and two orthodontists from other institutions. The evaluations revealed that a large number of patients over the age of 10 have multiple residual problems requiring further treatment. Only 23 percent of the older patients studied were judged to have had treatment completed by the surgeon, speech pathologist, and orthodontist. It is very difficult to state whether the results obtained by our team can be considered satisfactory because there are no comparable studies that have attempted to evaluate the same parameters in multidisciplinary management.

Adolescent↗
PubMed1991

Blood flow in expanded tissue treated with an anticontractile agent.

The present study investigates blood flow at several stages of expansion with and without enhancement by anticontractile agents (papaverine). Twelve 1-kg guinea pigs were divided into two groups. In group 1 were six animals undergoing tissue expansion without anticontractile agents, and in group 2 were six animals treated with a saturated solution of papaverine prior to expansion. Laser-Doppler velocimetry was used to monitor the changes in blood perfusion that occurred with each expansion. Animals pretreated with papaverine (group 2) maintained higher blood flow following inflation of the expander than untreated animals (group 1). This study provides physiologic evidence of the benefits of pharmacologic enhancement of the expansion process. Agents of this type may have a future role in the prevention of ischemic complications.

Animals↗
PubMed1991

Reflections on research.

The authors present their reflections on several of the major topics related to research. The subjects discussed include the quantity and quality of research; the motivation for research; the research process; research paradigm; restraints of research; and freedom to research. They point out that the haste to achieve success and to publish in most cases has precluded the learning process about the substance and methodology of research. An attempt is made to relate general problems of research and its methodology to research in the area of congenital facial deformities.

Cleft Lip↗
PubMed1990

Enhancement of expansion of guinea pig skin by local delivery of an anticontractile agent using a new bilumen expander.

We have shown previously that anticontractile agents used with tissue expanders provide significantly more rapid expansion in an animal model than in controls without these agents. We describe an improved method of delivery involving a perforated concentric envelope enclosing a tissue expander (type 2) in place of the single circumferential perforated catheter (type 1) used previously by us. Eleven guinea pigs received a type 1 expander and ten received a type 2 expander. The anticontractile agent theophylline was delivered in saline around each expander, and all the expanders from both groups were inflated to a similar pressure every three days for twelve days. Significantly greater expansion, in terms of total volume delivered to the expander, was noted using the type 2 expander. We conclude that the concentric device offers further improvement, probably as a result of more uniform distribution of the agent in the tissue around the expander.

Animals↗
PubMed1990

Serial measurement of blood flow in expanded tissue by laser Doppler velocimetry.

This study provides additional information about changes in blood flow in expanded tissue as measured by laser Doppler. Five one-kilogram albino Hartley guinea pigs were implanted with commercially available hemispheric expanders. The expanders were inflated every 3 days on four successive occasions. Blood flow measurements were taken on each animal just before each inflation, immediately after inflation, and then at 1, 2, 3, 4, and 24 hours after expansion. Measurement of flow changes immediately after each inflation of the expander showed that, initially, blood flow in the tissue overlying the expander recovered quickly, but as the expansion process was continued, the flow did not return to baseline values so rapidly. This might be an indication that tissue expansion in patients could be carried out more rapidly during the initial inflations, with increasing recovery periods between inflations as the expansion process continued.

Animals↗
PubMed1990

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↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1979

The relationship between lip pressure and facial growth after cleft lip repair: an experimental study.

Two different methods of lip repair were used on rabbits with surgically created unilateral clefts of the lip, alveolus, and palate. Control groups involved both unoperated animals and those with unrepaired surgically created clefts. The resulting lip pressure in the rabbits with repaired cleft lips was found to be significantly higher than in the control groups. Direct skull measurements showed that the rabbits whose lips had been surgically repaired also had significantly shorter maxillae that did the control groups. The correlation found between the amount of lip pressure and the degree of growth inhibition indicated a causal relationship.

Animals↗
PubMed1979

Influence of two-flap paltoplasty on facial growth in rabbits.

Three groups of rabbits were used in this study. Group I consisted of control rabbits who had had no surgery. Group II had surgically created but unrepaired clefts of the lip, alveolus, and palate. Group III had surgically created clefts of the lip, alveolus, and palate with the palatal clept having been repaired using a two-flap palatoplasty. At the end of the twentieth postoperative week, all animals were sacrificed. Results of the direct cephalometry of the skulls did not confirm the hypothesis that palatal repair inhibits overall facial growth. At the same time, certain asymmetries of the maxilla and mandible were found. These may have resulted from selective inhibition of certain growth processes.

Alveolar Process↗