Biomedical subjects

J Bardach

Publications and source records attributed to J Bardach.

At least 55 records · Page 3Linked to original sources

PubMed1984

Late results of primary veloplasty: the Marburg Project.

Forty-five randomly selected patients with unilateral cleft lip, alveolus, and palate, all operated upon by Dr. Wolfram Schweckendiek were evaluated by three American specialists to assess the validity of primary veloplasty. Examination revealed an unusually high incidence of short palate and poor mobility of the soft palate. Facial growth was found to be highly acceptable in the majority of the patients. Unusually high incidence of velopharyngeal incompetence was found in these patients.

Adolescent↗

PubMed1984

The relationship between lip pressure following lip repair and craniofacial growth: an experimental study in beagles.

In the present study with beagles, various states of lip pressure (decreased and increased) following surgical creation of the lip and palatal defects and subsequent lip repair were found to be significantly related to craniofacial growth aberrations and disproportions. These aberrations are discussed in terms of an imbalanced functional skeletal-soft-tissue matrix. Significantly elevated lip pressure following lip repair in group III animals was found to be more detrimental to craniofacial growth than decreased lip pressure resulting from the surgical creation of a defect left unrepaired. Results of the study present, for the first time, documented evidence of a significant relationship between lip pressure following lip repair and craniofacial growth. Caution should be employed in extending these conclusions to the clinical setting, yet the findings underscore the need for well-controlled clinical studies designed to assess the influence of cleft lip repair on craniofacial growth.

Alveoloplasty↗

PubMed1984

Lip pressure changes following lip repair in infants with unilateral clefts of the lip and palate.

The present study was designed to quantitatively assess lip pressure changes following cleft lip repair in infants with unilateral cleft lip, alveolus, and palate. Lip pressure measurements were taken using an electronic transducer system developed especially for this study. Lip pressure was monitored from 3 months (preoperatively) through 2 years of age in cleft and normal control children. Findings from the present study confirm the hypothesis that lip repair in infants with unilateral cleft lip and palate significantly increases lip pressure and that increased lip pressure remains significantly higher than in normal control children for the 2-year duration of the study. Thus increased lip pressure when the palate is unrepaired has to be considered as a factor modulating subsequent craniofacial growth.

Child, Preschool↗

PubMed1982

Titanium tray mandibular reconstruction.

Mandibular reconstructions still present a difficult and challenging problem. Failures experienced in using rib or iliac bone grafts stimulated clinical and research activities in evaluating the following new techniques: composite myocutaneous bone flaps, bone transplants with microvascular anastomoses, and freeze-dried homografts. This article describes the usefulness of the titanium tray with or without cancellous iliac bone grafts for mandibular reconstruction. The series presented herein includes 12 patients who underwent mandibular reconstruction after trauma or ablative cancer surgery, No immediate or delayed extrusion of the titanium tray was observed with follow-up as long as eight years after surgery. Advantages and disadvantages of this technique will be discussed.

Bone Transplantation↗

PubMed1982

Skull preparation using the exzyme-active detergent technique.

With the increasing use and need for macerated skulls and bony structures in medical research and resident and medical student studies, an economical, easy, and efficient method of obtaining cleaned and bleached specimens has been developed. The process requires short-term skeletal simmering in a 10% solution of commercially available enzymatic detergent and water. Over 50 skulls have been macerated in our laboratory resulting in substantial saving in research money, time, and effort.

Animals↗

PubMed1982

The significance of distal arteriovenous shunting on skin flap survival an experimental study in pigs.

Skin flap survival was studied experimentally in porcine flaps of constant width and varied lengths. No significant differences in flap surviving lengths were noted between 4 by 12 cm and 4 by 18 cm flaps. The concept that arteriovenous shunting in the distal portion of the flap adversely affects flap survival leads to the expectation longer flaps will have shorter surviving lengths than shorter flaps of the same width. Results of this study contradicted this hypothesis. If skin flap survival is determined by a progressive decrease in perfusion pressure as distance from the base of a flap increases, then vascular demand distal to the line of capillary perfusion should be of no consequence. Results of this study are consistent with this hypothesis.

Animals↗

PubMed1982

Changes in quantitative norepinephrine levels in delayed pig flank flaps.

A quantitative norepinephrine assay was used to follow tissue norepinephrine concentrations serially in bipedicle delayed pig flank flaps. In contrast to a previous study by Palmer, norepinephrine concentration decreased significantly after 24 hr, but then gradually returned to normal at 10 days. This suggests that the pig flank flap maintains much of its adrenergic innervation following bipedicle delay. It appears unlikely that adrenergic denervation explains the delay phenomenon in this model. The combined results of this study and others suggest that the degree of adrenergic denervation of a flap is determined by the anatomic layout of the flap with respect to the underlying cutaneous adrenergic neural anatomy. This experiment suggests that the effectiveness of adrenergic blocking agents in improving flap survival is dependent on the degree of adrenergic denervation of the flap.

Animals↗

PubMed1982

A comparative study of facial growth following cleft lip repair with or without soft-tissue undermining: an experimental study in rabbits.

The present study was performed in rabbits to test the hypothesis that incisions in the sulcus and soft-tissue undermining at the time of cleft lip repair contribute more to midfacial growth inhibition and aberrations than lip repair only. The design of this study, using three control groups, permitted assessment of the effects of soft-tissue undermining independently of the other surgical procedures. This study revealed that lip repair combined without soft-tissue undermining. Direct cephalometry on the skulls indicated that anteroposterior facial growth was most severely affected mean quantitative assessment revealed that anteroposterior facial growth inhibition was significantly greater when lip repair was combined with soft-tissue undermining than without. Maxillary width was found to be the greatest in groups 3 and 4 compared with the other two groups. Mean quantitative assessment revealed that lip repair with or without soft-tissue undermining was shown to overcorrect normal transversal growth. Significant growth aberrations also were found in maxillary height, posterior facial height, and nasal deflection. Constant high lip pressure can be explained as a result of an interaction of lip repair and scar contraction from soft tissue undermining. Results of this study cannot be readily transferred to the clinical setting, but they present the first documented evidence elucidating the influence of soft-tissue undermining on facial growth. Further experimental and clinical research is needed to determine the extent of growth inhibition that may be related to the use of this procedure.

Animals↗

PubMed1982

The influence of two-flap palatoplasty on facial growth in beagles.

This study was designed to test the hypothesis that palate repair in beagles inhibits overall facial growth, primarily in the transversal dimension. Direct cephalometry of the skulls at 28 weeks postoperatively showed that two-flap palatoplasty did not inhibit overall facial growth in animals with surgically created cleft lip, alveolus, and palate. In many cases, facial growth in animals with palate repair was indistinguishable from that in unoperated control animals. The unexpected finding in this study was that two-flap palatoplasty seemed to stimulate intensive new bone formation in the surgically created alveolar and palatal defects. Bony remodeling may be responsible for the enhanced anteroposterior and transversal facial growth in animals with palate repair (group 3). The results of this study validate findings from our previous studies in the rabbit model; yet caution should be employed in extrapolation of these findings to the clinical setting. For the first time, evidence is presented that in normal beagles with surgically created alveolar and palatal defects, two-flap palatoplasty stimulated substantial and, significant new bone formation in the site of the defects. Studies should be designed to determine the nature and time course of bony palatal wound healing.

Animals↗

PubMed1981

Haemodynamics of the delayed skin flap: a total blood-flow study.

Pedicle skin flaps in dogs were delayed and venous outflow measured at various times following a delay procedure. An initial small but significant decrease in blood flow was noted in the first 48 hours postoperatively in several flaps suggesting that a denervation supersensitivity-arteriovenous shunt mechanism may be active at this time. In all flaps after the second day, total flap blood flow markedly increased compared to the initial measurement. This suggests that the most significant haemodynamic event occurring during the delay period is the development of vascular collaterals.

Animals↗

PubMed1980

Skin flap delay procedures: proximal delay versus distal delay.

An experimental study was designed to determine which portion of a flap, distal or proximal, contributes more to the delay phenomenon. (Since flap necrosis usually occurs in it distal portion, it is often assumed that only this portion of a flap must be delayed to improve flap survival.) Random-pattern pig flank flaps (16 X 3 cm) were used. All control flaps survived to at least 8 cm. Survival of flaps in which the distal half was delayed was not significantly different from that of controls. Survival of flaps in which the proximal half was delayed was significantly greater than undelayed controls. Completely delayed flaps, however, had significantly better survival than any other group. These findings are inconsistent with the metabolic adaptation hypothesis. They suggest that the denervation supersensitivity-arteriovenous anastomosis hypothesis is incorrect. They are consistent with the vascular collateral hypothesis and the new basal capillary shunting hypothesis.

Animals↗

PubMed1980

The influence of simultaneous cleft lip and palate repair on facial growth in rabbits.

This study was designed to test the influence of simultaneous cleft lip and palate repair on facial growth in rabbits. Three groups of rabbits were used. Group I consisted of control rabbits who had no surgery; Group II had surgically created, but unrepaired, clefts of the lip, alveolus, and palate; and Group III had surgically created clefts of the lip, alveolus, and palate followed by immediate simultaneous lip and palate repair. In Group III, the lip was repaired using the Millare technique and the palate using two-flap palatoplasty, leaving no bare bone exposed. All animals were sacrificed after twenty weeks. Results of the direct cephalometry of the skulls confirmed that simultaneous lip and palate repair results in inhibition of anterior-posterior and transverse maxillary growth. Some significant changes were also found in mandibular length and nasal deflection. All 15 rabbits with simultaneous cleft lip and palate repair developed anterior crossbites and functional shifts to the left or cleft side. Further analysis comparing the results of facial growth inhibition in this study with inhibition following lip repair only or palate repair only will be necessary to assess the severity of secondary maxillo-facial deformities resulting from lip and palate repair.

Animals↗

PubMed1980

Preserved irradiated homolgous cartilage for orbital reconstruction.

Human costal cartilage is an excellent implant material for orbital and periorbital reconstruction because of its light weight, strength, homogeneous consistency and the ease with which it can be carved. Its use has been limited by the necessity of a separate surgical procedure to obtain the material. Preserved irradiated homologous cartilage has been shown to have almost all the autogenous cartilage and is concenient to use. Preserved irradiated homologous cartilage transplants do not elicit rejection reactions, resist infection and rarely undergo absorption.

Adolescent↗

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↗

PubMed1977

Irradiated homologous costal cartilate for facial contour restoration.

This study represents a retrospective evaluation of 145 implants of irradiated homologous costal cartilage used over a three-year period for facial contour restoration in a variety of anatomic sites. In this series, the immediate complication rate was 5.5%, the late complication rate was 2.1% and the partial resorption rate was 1.4%. The infection rate for the implants inserted intraorally onto the face of the maxilla did not have a statistically significant difference from the infection rate for the entire series, thus demonstrating that this implant is not easily infected. These results establish irradiated homologous costal cartilage as a valid implant material.

Adolescent↗

PubMed1977

Reconstruction of intraoral defects with the free groin flap.

A free flap has been defined as an island flap that has been completely detached from the body and transferred to a distant recipient site, where microvascular anastomoses are done to reestablish its essential intravascular circulation. The groin flap, based on its superficial circumflex iliac artery and venae comitantes, was utilized as a free flap to close large intraoral defects in six patients following ablative cancer operations. All patients received preoperative or postoperative irradiation therapy. Four of the six free groin flap operations were clinically successful. One flap became necrotic unexpectedly after 3 1/2 weeks. Infection played a major part in necrosis of the other flap. The use of the free flap in oral cavity reconstruction offers certain advantages over regional vascular flaps but definite limitations exist.

Adult↗

PubMed1977

Microsurgical techniques in free flap reconstruction.

Free flap reconstruction is discussed with emphasis on microsurgical technique utilized in union of blood vessels 1 mm in external diameter. Proper microsurgical instrumentation, magnification and small vessel suture technique are all of importance in achieving a successful microvascular anastomosis. Technical maneuvers employed in identifying and avoiding small vessel thrombosis are presented. Surgical techniques, as presented here, have allowed us to successfully use free flaps to reconstruct large oral cavity defects following ablative cancer operations.

Blood Coagulation↗