Search PubMed⌕ Search

Biomedical subjects

L B Kaban

Publications and source records attributed to L B Kaban.

At least 73 records · Page 4Linked to original sources
PubMed1993

Diagnosis and treatment of fractures of the facial bones in children 1943-1993.

It is clear that the foundations for diagnosis and the basic principles of management have changed little since 1943 and probably since the work of Kazanjian in World War I. Major advances have occurred, with modern techniques of airway management (particularly fiberoptic laryngoscopy), anesthesia, and an understanding of fluid and electrolyte balance and behavioral issues in children. In addition, the advent of antibiotics; new imaging techniques (particularly CT), and availability of new instrumentation and rigid internal fixation have all revolutionized the specific treatment of pediatric facial fractures. Craniofacial techniques, pioneered by Dr Paul Tessler, have significantly altered and improved treatment of pediatric midface fractures. Progress in the biology of bone healing will surely mark the next 50 years.

Accidents, Traffic↗
PubMed1993

Long-term viability of the temporalis muscle/fascia flap used for temporomandibular joint reconstruction.

Temporalis muscle/fascia axial flaps (TFs) were used in 115 temporomandibular joints (TMJs) in 81 patients to correct ankylosis (n = 25 joints), traumatic defects (n = 8), congenital anomalies (n = 4), defects resulting from tumor resection (n = 2), degenerative joint disease (n = 52), autoimmune arthritides (n = 21), and lateral capsule flaccidity (n = 3). The follow-up period ranged from 6 months to 5.5 years. Seven patients (8.6% of the group; 10 TMJs) were reevaluated for recurrent symptoms (pain and decreased motion), with a mean of 1.7 years (range = 1 to 3 years) postoperatively. Four of these patients (seven TMJs) had magnetic resonance imaging (MRI) as part of their diagnostic workup and four patients (five TMJs) required a second operative procedure. This study reports the results of the MRI, intraoperative, and histologic evaluations of the TFs in these seven patients. The MRIs showed vascularized tissue between the condyle and roof of the glenoid fossa in all seven joints examined. The signal was consistent with muscle and/or fat as opposed to scar tissue. All flaps examined at the time of surgery (arthroscopy, n = 1; arthrotomy, n = 4) were in place and had the gross appearance of normal muscle. Histologic examination of biopsies of four flaps indicated the presence of viable muscle with normal-appearing nuclei. The results of this study indicate that the TF does survive when it is carefully dissected and inferiorly based to preserve blood supply.

Fascia↗
PubMed1993

Fetal cleft lip repair in lambs: histologic characteristics of the healing wound.

Sequential surgical procedures in cleft lip/palate (CL/P) patients result in scar formation that is believed to be associated with midface growth retardation. By use of a previously developed fetal lamb model, wound healing characteristics were investigated after in utero CL repair. It is hypothesized that scarless healing after fetal CL repair occurs without inflammation and scar formation. CL wounds were created in mid-second-trimester fetal lambs and either repaired in three layers (mucosa, muscle, and skin) or left unrepaired. Fetuses were then harvested at 7, 14, and 21 days postoperatively, and the wound site was examined microscopically. When created at 75 days' gestation (term = 145 days), fetal lamb CL wounds heal rapidly without inflammation and scar formation. By day 21 postoperatively, there was complete regeneration of skin, muscle, and mucosa, as well as epidermal appendages. With this model, it will be possible to compare the effects of scarless fetal CL repair with those of postnatal repair on midface growth.

Animals↗
PubMed1993

Fetal cleft lip repair in rabbits: long-term clinical and cephalometric results.

We have developed a model for fetal cleft lip (CL) repair in rabbits. To date, the in utero CL procedure has been performed on 174 fetuses in 98 pregnant does. Details of the model, wound healing characteristics, and early growth results have been published previously. In this study, we report long-term clinical and cephalometric findings in 23 fetuses who underwent the fetal CL procedure, were born alive, and survived until completion of growth. The surgically created and repaired CL in fetal rabbits described here resulted in healing without scar formation. The deformity varies from an incomplete to a severe complete cleft, resembling the clinical spectrum of spontaneous clefts in humans. Cephalometric studies indicate that there were no statistically significant differences in premaxillary width, anterior maxillary length, or anterior and posterior maxillary width among control, unrepaired, and repaired animals. Documentation of this phenomenon in higher animals is necessary before the technique can be applied to humans with cleft lip.

Animals↗
PubMed1993

Injuries to the inferior alveolar and lingual nerves.

Both the inferior alveolar and the lingual nerve are at risk for damage following various surgical procedures. Sensory nerve function following potential damage should be tested and evaluated for treatment, with microneurosurgery considered under certain conditions. Repair between three and six months following injury has the best results. A study of 43 patients who underwent microneurosurgery for various types of injuries, and have been followed for at least one year, found four (9.3 percent) with essentially complete return of sensation; five (11.6 percent) with good return; 19 (44.2 percent) with some return; 13 (30.2 percent) with no return; and two (4.6 percent) with a decrease in sensation.

Dental Care↗
PubMed1992

Fetal cleft lip repair in rabbits: histology and role of hyaluronic acid.

This study examines the histologic and biochemical features of wound healing in a cleft lip model in the mid-third-trimester fetal rabbit. At days 1, 2, and 4 after the procedure, control, unrepaired, and repaired fetal heads were obtained, sectioned, and stained for histologic examination. The localization of hyaluronic acid in the wound was documented using a cartilage-derived hyaluronic acid-binding protein. In both repaired and unrepaired wounds, the fetal cleft healed without inflammatory cell infiltration or scar formation. Six months after birth, the repaired cleft showed complete regeneration of muscle across the wound and the collagen fibers were of normal density and orientation. Decreased hyaluronic acid deposition was observed in unrepaired clefts as compared with adjacent tissue; no such difference was detected in repaired clefts. Our findings support the hypothesis that a cleft lip repaired in utero heals without the scarring that accompanies postnatal repair. This may explain the lack of maxillary growth restriction after in utero cleft lip repair.

Animals↗
PubMed1992

The use of fresh frozen allogeneic bone for maxillary and mandibular reconstruction.

The use of fresh frozen bone (FFB) alone, or in combination with autogenous bone (AB), for bony augmentation of the maxilla and mandible in preparation for dental reconstruction with endosseous implants has been studied. Ten patients received FFB +/- AB for augmentation of a severely atrophic mandible (n = 6) or for reconstruction of a jaw defect secondary to trauma or tumor resection (n = 4). Average follow-up was 26.3 +/- 5.4 months. At the time of implant placement, the bone grafts were found to be firm in consistency, well incorporated, and well vascularized in all 10 patients. Twenty-nine endosseous implants were placed an average of 8.3 +/- 3.1 months following bone grafting. One implant failed and was replaced, and one implant remains buried as a nonfunctional unit. All patients have been restored prosthetically by means of 28 of the 29 implants. This preliminary study indicates that FFB may be used alone or in combination with autogenous bone for augmentation or reconstruction of the atrophic maxilla and mandible. The resultant ridge is adequate to support loaded endosseous implants. A potential disadvantage is the minimal risk of disease transmission.

Bone Transplantation↗
PubMed1992

An in utero model of craniosynostosis.

To define better the pathophysiology of craniosynostosis, we developed an in utero model in rabbits. Premature fusion of the sutures was achieved by osteoinduction using demineralized bone matrix (DBM). Thirty-six fetuses from 18 time-dated pregnant rabbits underwent coronal strip craniectomies and implantation of DBM at 25 days of gestation (term = 31 days). Seventeen (47%) survived vaginal delivery and 10 (28%) survived for long-term follow-up. Surviving, operated animals demonstrated bony fusion across the coronal sutures presumably due to osteoinduction by the DBM. Coronal computed tomographic scans with sagittal reconstructions revealed that experimental animals had taller and wider skulls than nonoperated control animals. We conclude that employing DBM to create craniosynostosis in the fetal rabbit is technically feasible. Such a model may be used to more clearly define the pathophysiology of craniosynostosis and to evaluate methods of treatment.

Animals↗
PubMed1992

A model for fetal cleft lip repair in lambs.

Fetal wounds heal without inflammation and scar formation. This phenomenon may, in the future, be applicable to human cleft lip and palate repair. However, extensive experimental work must first be done to document the benefits of in utero repair. We developed a large animal model for creation and repair of a complete cleft lip and alveolus using fetal lambs. The cleft lip and alveolus deformity was created in eight 75-day-gestation fetuses (term = 145 days) and either repaired in three layers or left unrepaired. There were four sham-operated fetuses, and all animals were alive at harvest. Repaired, unrepaired, and control fetuses were harvested at 7, 14, 21, and 70 days following surgery. The unrepaired fetuses demonstrated a complete cleft lip and alveolus with an oronasal fistula. The maxilla was asymmetrical, with the greater segment deviated toward the cleft and with decreased anterior maxillary width. In contrast, repaired cleft lip and alveolus animals showed no scar, normal thickness of the lip, and a symmetrical maxilla. Histologic analysis of the repaired wounds showed evidence of tissue regeneration without scar formation. The results of this preliminary study indicate that the fetal lamb cleft lip and alveolus model is technically feasible with an excellent survival rate. Healing occurs without scar formation. In the repaired animals, the maxilla was symmetrical. This model will be used to document facial growth following in utero repair of a cleft lip and alveolus.

Alveolar Process↗
PubMed1992

Surgically assisted rapid maxillary expansion in adults.

Twelve adults with maxillary width discrepancy of greater than 5 mm were treated by surgically assisted rapid maxillary expansion. The procedure consisted of bilateral zygomatic buttress and midpalatal osteotomies combined with the use of a tooth-borne orthopedic device postoperatively. Mean palatal expansion of 7.5 mm (range of 6 to 13 mm), measured in the first molar region, was achieved within 3 weeks in all patients. Expansion remained stable during the 12-month study period, with a mean relapse for the entire group of 0.88 +/- 0.48 mm. Morbidity was limited to mild postoperative discomfort. The results of this preliminary study indicated that surgically assisted rapid maxillary expansion is a safe, simple, and reliable procedure for achieving a permanent increase in skeletal maxillary width in adults. Further study is necessary to document the three-dimensional movements of the maxillary segments and long-term stability of the skeletal and dental changes.

Adolescent↗
PubMed1991

Predictors of outcome in children hospitalized with maxillofacial infections: a linear logistic model.

The purpose of this study was to determine factors predictive of clinical outcome for pediatric patients with maxillofacial infections. Using linear logistic regression, four important variables, age, admission temperature, admission white blood cell count, and source of infection, were identified. Relevant study variables were abstracted from the records of all children less than 15 years old admitted to San Francisco General Hospital (SFGH) with facial infections between 1982 and 1986 (n = 105). An unfavorable clinical outcome was defined as a length of hospital stay (LOS) greater than or equal to 4 days and/or the need for an operation to resolve the infection. A favorable outcome was a LOS less than 4 days and no operation. To develop and validate the linear logistic model, the original group of patients (n = 105) was divided into index and validation sets. The index set was created by randomly selecting 80 of the original patients. The model was then applied to a validation set of the 25 remaining children. The model predicted that 13.95 of the patients in the validation set would have an unfavorable outcome. The actual number of unfavorable outcomes was 16. To further test the model's validity, a third data set was collected. It was composed of pediatric patients admitted to SFGH between January 1, 1987 and June 30, 1989 (n = 24). The model predicted that 15.99 of these patients would have an unfavorable outcome; 17 patients actually did have an unfavorable outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Infections↗
PubMed1991

Fetal cleft lip repair in rabbits: postnatal facial growth after repair.

We have previously described a model for in utero cleft lip repair in rabbits. Cleft lip and alveolus (CL) were created in fetal rabbits at 24 days gestation (term, 31 days). In this study, postnatal maxillary growth was evaluated in three groups of animals: 1) unoperated controls, 2) unrepaired CL, and 2) repaired CL. The animals were killed at 4, 12, and 26 weeks after birth. Direct cephalometry was performed on dry skulls to evaluate premaxillary width, anterior maxillary length and width, and posterior maxillary width. The results of this study indicate that rabbits that undergo an in utero CL procedure, with or without repair, exhibit no significant decrease in maxillary length and width when compared with controls.

Alveolar Process↗
PubMed1991

Bicoronal flap approach to the temporomandibular joints.

The bicoronal scalp flap provides an excellent approach to the temporomandibular joint, particularly in cases where bilateral operation is required. It is also indicated when wide exposure is required and when previous surgery may make more conventional techniques difficult. In this report, the anatomy and indications for this approach are reviewed, the operative technique is described and complications are discussed.

Ankylosis↗
PubMed1991

[DNA cytophotometric studies of central giant-cell lesions of the jaw region].

Giant cell nuclear DNA, in 30 giant cell lesions of the jaws, was quantitated by computer-assisted image analysis. DNA content was then used to predict clinical behavior and outcome. Four.nuclei in each of 25 giant cells (total = 100 nuclei) were randomly selected and DNA content was quantitated by the LEITZ Texture-Analysis-System-Plus. DNA in nuclei of normal appearing stromal fibroblasts (n = 20) was similarly measured. DNA index was calculated as the mean nuclear DNA content of giant cells divided by mean DNA content of control fibroblasts. The mean DNA index of aggressive lesions (1.09, S. D. = 0.12) was not significantly different from that of non-aggressive lesions (1.18, S. D. = 0.15) (p = 0.093). The results indicate that nuclear DNA content of giant cells is not useful as a predictor of clinical behavior of giant-cell lesions of the jaws.

Adolescent↗
PubMed1991

Age effects on bone induction by demineralized bone powder.

It has been previously shown that osteoinduction by demineralized bone powder (DBP) in the rat decreases as the age of the recipient animal increases. In the present study, the effects of age on osteoinduction by DBP were evaluated in the rat by varying the age of the donor and the recipient animal. Cartilage and bone formation in subcutaneous pouches was assessed using a histologic grading technique in which a composite score was derived from analysis of multiple histologic sections from each specimen. The results confirm the previously reported decrease in osteoinduction in middle-aged adult animals compared with younger ones. However, DBP prepared from middle-aged adult rats was more inductive than that prepared from either prepubertal or young postpubertal animals. The latter result contradicts the widely held belief that demineralized bone matrix from younger animals is more inductive than that from older ones. This finding may help to further elucidate the mechanism of ectopic bone formation and lead to more inductive bone graft substitutes for human use.

Aging↗
PubMed1990

A rabbit model for fetal cleft lip repair.

Recent clinical and experimental data indicate that fetal wound healing occurs without the accompanying inflammation and scar formation typical of postnatal wounds. The lack of scar tissue may have significant implications for craniomaxillofacial surgery. This report documents the development of a model for fetal cleft lip repair in rabbits. The survival rate for the first 47 fetuses was 76.6%.

Animals↗