Biomedical subjects

J L Marsh

Publications and source records attributed to J L Marsh.

At least 163 records · Page 9Linked to original sources

PubMed1990

Standardization for the reporting of nasopharyngoscopy and multiview videofluoroscopy: a report from an International Working Group.

A multidisciplinary International Working Group of scientists was assembled to address the question of standardizing reporting techniques for multiview videofluoroscopy and nasopharyngoscopy, the generally accepted standards for direct observation of the velopharyngeal valve. This report is a first attempt to propose standards while seeking feedback from the readership in order to further develop a common methodology.

Cineradiography↗

PubMed1990

Agnathia and associated malformations: a case report.

A case of a rare first branchial arch anomaly with severe hypoplasia of the mandible and fusion between the mandible and adjacent bones is presented. The patient also had intracranial, cardiac, and acral deformities. The craniofacial malformations may reflect incomplete separation of the first branchial arch into its maxillary and mandibular processes. The association between the craniofacial and other corporal anomalies is unknown.

Branchial Region↗

PubMed1990

External fixation for open tibia fractures. A management strategy.

The management of open tibia fractures with the Dynamic Axial Fixator, including the method of application and postoperative care, is described. This fixator is utilized until healing. Weight bearing and axial fracture site movement promote an early callus response. The results obtained in the first 35 cases in which it was used at our institution are presented. Thirty-three of the fractures were successfully treated until healing in the external fixator.

Fracture Fixation↗

PubMed1990

Mechanical analysis of the factors affecting dynamization of the Orthofix Dynamic Axial Fixator.

Loading trials were conducted to identify mechanical factors affecting dynamization of a commercially available external fixator (Orthofix) that is designed to undergo free telescopic motion when axially loaded. Angular variations between the proximal and distal screw clamps and the telescoping fixator body failed to produce fixator binding (failure to dynamize) in any of the loading trials. However, binding was produced by applying external torques in magnitudes that occasionally occur during routine ambulation. The specific torque necessary to induce binding (typically 3-4 Nm) was only a weak function of axial load magnitude, axial loading frequency, or simulated fracture stiffness. Among several geometrical variables of fixator application, only the pre-extension of the telescoping body and circumferential misalignment between proximal and distal pin clusters had an appreciable influence on the threshold binding torque. Axial fixator motions were also monitored in a small adjunct clinical series of 22 dynamized tibial fractures. The fixator dynamized appropriately in 15 cases (68%). Three patients (14%) showed evidence of fixator binding, and another four (18%) had less than predicted slider excursions. The role of several design factors implicated in torque-induced fixator binding is discussed in light of the benchtop and clinical observations.

Biomechanical Phenomena↗

PubMed1990

Craniofacial onlay bone grafting: a prospective evaluation of graft morphology, orientation, and embryonic origin.

A prospective study using 46 young adult New Zealand rabbits was designed to evaluate onlay bone grafts to the craniofacial skeleton with respect to embryonic origin (membranous or endochondral), gross morphology (unicortical or bicortical), and orientation (cortex-to-bed relationship). Quantitative and qualitative data were analyzed and contrasted at both periods of evaluation (1.5 and 3.0 months). The embryonic origin of onlay bone grafts to the rabbit snout is significantly correlated with graft surface area, volume, weight, and recipient bed union for up to 3 months postoperatively. Over this interval, membranous bone (calvaria) grafts either persist in their entirety or increase, whereas endochondral bone (iliac) grafts resorb. Neither the number of cortices (unicortical or bicortical) nor the orientation of unicortical grafts (cortex-to-bed relationship) affected graft fate regardless of embryonic origin. Bone density remained unaltered during both resorption and deposition. Osteogenesis, demonstrated by serial fluorochrome markers, occurs in both membranous and endochondral bone grafts. Histologically, bone grafts of membranous and endochondral origin differ greatly in their cortical to cancellous diploe ratios and architectural configuration. We hypothesize that the differences found are related to the three-dimensional osseous architecture rather than to the embryonic origin of bone per se.

Animals↗

PubMed1990

When is enough enough? Secondary surgery for cleft lip and palate patients.

Secondary cleft surgery differs from the primary surgery in two important respects: (1) the patient can participate in the choices of whether and how to proceed and (2) there is no universal consensus among professionals and lay persons alike that intervention is necessary. This article condenses a personal experience with secondary cleft surgery and attempts to answer "when is enough enough?"

Adolescent↗

PubMed1990

Indium-111-leukocyte/technetium-99m-MDP bone and magnetic resonance imaging: difficulty of diagnosing osteomyelitis in patients with neuropathic osteoarthropathy.

Fourteen patients (16 sites) with clinical and/or radiographic evidence of neuropathic osteoarthropathy (Charcot joints) were evaluated with combined indium-111-leukocyte (111In-WBC) and technetium-99m-methylene diphosphonate (99mTc-MDP) bone imaging for suspected osteomyelitis. Magnetic resonance (MR) images were obtained in seven patients. Using a positive bone culture as the criterion for the presence of osteomyelitis, there were four true-positive studies, six true-negative sites, and one false-negative 111In-WBC study. Five of 16 sites (31%) had false-positive 111In-WBC uptake at noninfected sites. There were four true-positive and three false-positive MR studies. All false-positives showed at least moderately abnormal findings by both techniques at sites of rapidly progressing osteoarthropathy of recent onset. In this preliminary study, both techniques appear to be sensitive for detection of osteomyelitis, and a negative study makes osteomyelitis unlikely. However, the findings of 111In-WBC/99mTc-MDP and MR images at sites of rapidly progressing, noninfected neuropathic osteoarthropathy may be indistinguishable from those of osteomyelitis.

Adult↗

PubMed1989

Soft tissue cervical spinal injuries in motor vehicle accidents.

Soft tissue cervical spinal injuries occurred in 179 out of 1197 consecutive victims of road traffic accidents who needed to attend hospital; an incidence of 15 per cent. It was most common in female (P less than 0.01), restrained car occupants (P less than 0.05) in the 40-49 years age group (P less than 0.025). It was less common in rear seat passengers (P less than 0.001). Most were victims of collisions from the rear but significant numbers also occurred in other types of accidents. The incidence of associated injuries was low.

Accidents, Traffic↗

PubMed1989

Craniosynostosis: diagnostic value of three-dimensional CT reconstruction.

Three-dimensional computed tomography (CT) has an important role in determining the presence and extent of congenital and acquired craniofacial deformities. The authors compared the sensitivity and specificity of three-dimensional CT in the detection and characterization of craniosynostosis with that of planar CT and skull radiography. Eighty-two patients with isolated and syndromal synostoses were imaged with CT and three-dimensional CT, and 42 with skull radiography. Three-dimensional CT scan processing was performed by shaded-surface reconstruction, volumetric, and depth-coded methods. Two trained observers read each scan series in a blinded fashion. Diagnostic utility of the images was determined with receiver operating characteristic analysis. The observers ranked three-dimensional shaded images higher than the other types, with three-dimensional volumetric images second and three-dimensional surface images ranked third. Results of this study demonstrate that three-dimensional shaded-surface reconstruction from CT scans is superior to conventional plain radiographs and CT scans in diagnosing craniosynostosis.

Adolescent↗

PubMed1989

Craniosynostosis: image quality, confidence, and correctness in diagnosis.

The authors used the diagnosis of craniosynostosis to compare subjective evaluation of image quality with objective diagnostic utility. They studied in detail the responses of one observer, who read plain radiographs, computed tomographic (CT) scans, and three-dimensional reconstructions of CT scans (obtained with three different methods) for 82 patients with this diagnosis. The observer rated image quality and certainty in diagnosis made from each image. Subjective and objective performances were found to be strongly linked. High-quality images served as the basis for more accurate diagnoses than low-quality images. The increase in diagnostic performance results primarily from increased specificity, a fact that suggests that specificity and the concomitant diagnosis of normalcy are the focus of attention when image quality is evaluated.

Adolescent↗

PubMed1989

Detection of osteomyelitis at fracture nonunion sites: comparison of two scintigraphic methods.

Forty-nine patients with 50 fracture nonunions 4-48 months after injury underwent technetium-99m methylene diphosphonate (99mTc-MDP) scintigraphy on day 1, combined 99mTc-MDP and indium-111 leukocyte (111In-WBC) scintigraphy on day 2, and gallium-67 (67Ga) scintigraphy on day 3. The results were compared to evaluate the relative abilities of these scintigraphic techniques to detect osteomyelitis. Nine patients had clinical evidence of infection at the time of imaging, and 40 patients (41 fractures) did not. Open-biopsy cultures were performed at all fracture sites and were positive at 21 (42%) of the 50 sites. Combined 99mTc-MDP/111In-WBC images were interpreted with the use of two criteria. A positive study by the first criterion required 111In-WBC localization in the region of the nonunion fracture. A positive study by the second criterion required 111In-WBC localization in bone at the fracture site. The first criterion yielded a sensitivity of 84%, specificity of 72%, and accuracy of 74%; the specificity improved to 97% with an accuracy of 88% when the second criterion was used. Ten (25%) of the 40 patients thought not to have osteomyelitis by clinical criteria at the time of imaging had true-positive 99mTc-MDP/111In-WBC studies by biopsy culture results. Gallium-67 studies were interpreted as nondiagnostic if localization of radioisotope at fracture sites was equal to that with 99mTc-MDP, positive if 67Ga localization was greater than that of 99mTc-MDP, and negative if it was less than that of 99mTc-MDP. Twenty-one 67Ga studies were interpreted as nondiagnostic; 11 (52%) of the 21 had culture-positive fracture sites. The accuracy of 67Ga/99mTc-MDP imaging was 39%. Combined 99mTc-MDP/111In-WBC imaging is useful in the detection of osteomyelitis at fracture nonunion sites and improves the specificity of 111In-WBC imaging by differentiating inflammation/infection in adjacent soft tissue from osteomyelitis at the fracture site. Gallium-67 with 99mTc-MDP imaging is not sufficiently reliable in this clinical setting to be useful as an indicator for osteomyelitis.

Adult↗

PubMed1989

Three-dimensional surface imaging from CT scans for the study of craniofacial dysmorphology.

Computer-assisted medical imaging technologies provide new tools for the study of congenital craniofacial deformities. Three-dimensional surface reconstructions have been developed to simplify the interpretation and improve the utility of CT scans of the head. While 3-D reconstructions initially were applied to assist clinical management of craniofacial deformities, these images now are finding utility in the study of unique anomalies, the definition of group characteristics for dysmorphic heads, the differentiation of similar phenotypes, and the documentation of the effects of cranial surgery on craniofacial growth. These findings should assist the formulation and evaluation of hypotheses regarding mechanisms of congenital malformation and deformation.

Adolescent↗

PubMed1989

Maxillofacial osteotomies for patients with cleft lip and palate.

A variety of dental malocclusions may be found in the patient with cleft lip and palate. These range from trivial dental rotation to major dentoskeletal disharmonies. Some of these deformities are intrinsic to the cleft malformation whereas others are secondary deformations resultant from specific management options taken in childhood. In most cases, a combination of orthodontics and orthognathic surgery is necessary to correct the deformity, that is, normalize the dentition, the facial skeleton, and the facial appearance. The timing of intervention, dependent upon the specific problem, is chosen to minimize negative secondary effects. Stability of mobilized and repositioned maxillary segments remains a problem in spite of the use of rigid internal fixation miniplates. The role of bone grafting when miniplates are used is unclear. While it is clear that movement of the maxilla, segmentally or in toto, can correct major dentoskeletal deformities in cleft patients, much remains to be learned regarding the best means of executing such operations.

Cleft Lip↗

PubMed1989

Internal fixation of malar fractures: an experimental biophysical study.

Open reduction and internal fixation of displaced zygoma fractures are necessary to avoid immediate and delayed facial disfigurement. Interosseous wires, Kirschner wires, and more recently, rigid metallic miniplates have been recommended for fixation of these and other midfacial fractures. However, the precise physical stability of the zygoma with respect to wire versus miniplate fixation methods and with respect to the number and location of miniplates applied is not known. Noncomminuted zygoma fractures were simulated by saw osteotomy in eight fresh human cadaver heads (16 zygoma "fractures"). Each zygoma was sequentially fixated with three miniplates, two miniplates, one miniplate, and three interosseous wires across the orbital rim and arch "fractures". Static and oscillating loads simulating maximal physiologic masticatory stresses were applied to the fixated zygoma along the lines of action of the masseter muscle by means of a tensometer. The stability and adequacy of each pattern of fixation were recorded. Double-miniplate fixation across the orbital rim of simulated noncomminuted zygoma "fractures" is sufficient to withstand static and oscillating loading similar to physiologic masticatory forces. Neither single-miniplate fixation nor triple-wire fixation are sufficient to stabilize the zygoma against similar forces.

Biophysical Phenomena↗

PubMed1989

Reliability of flexible fiberoptic nasopharyngoscopy for evaluation of velopharyngeal function in a clinical population.

Flexible fiberoptic nasopharyngoscopy (FFN) has become a popular clinical tool for evaluating velopharyngeal function. The literature contains numerous reports of FFN methodology and findings. However, there are few published reports that address clinical rating and reporting schemes or that evaluate viewer reliability. This study was designed to evaluate the reliability of visual perceptual ratings of FFN video images for assessing velopharyngeal structure and function in a clinical population. Ninety-five videotaped clinical evaluations were presented to and judged by three expert raters and nine novice raters from the fields of speech pathology, otolaryngology, and plastic surgery, using a standard rating form. A clinical rating scheme was used for quantifying perceptual judgments of velopharyngeal activity. Results suggest that videotaped FFN evaluations may be rated reliably, that expert raters working as a group are more reliable than novice raters working individually, and that the 125 evaluations presented without feedback are insufficient to improve the novices' reliability. The combined auditory and visual perceptual evaluation inherent in FFN may be its most significant asset for both clinical and research applications.

Adolescent↗

PubMed1989

Facial musculoskeletal asymmetry in hemifacial microsomia.

Computer-assisted medical imaging--transaxial computed tomography (CT) scans and three-dimensional surface reconstructions--was used to study the muscles of mastication and their osseous origins and insertions in 24 patients with untreated unilateral hemifacial microsomia (HFM). The relationship between the volume of a muscle of mastication and the shape and size of its origin and insertion in such patients varies widely. Comparison of mean volumes of specific muscles documents a statistically significant decrease among patients who have moderate to marked mandibular dysmorphology as compared with those with minimally dysmorphic mandibles. This study supports the hypothesis that the shape and size of the mandible are related to the muscles that originate and insert upon it. However, the variation among individual patients means that assumptions regarding muscle mass and, in turn, function cannot be made regarding an individual patient on the basis of osseous dysmorphology that has been demonstrated on skull radiographs alone.

Adolescent↗

PubMed1989

Intravelar veloplasty: a prospective study.

Preliminary results are reported from a prospective, alternated, single-institution study of the effect of intravelar veloplasty (IVV) upon postpalatoplasty velopharyngeal incompetence. Two senior surgeons standardized their operative procedures and then performed or directly supervised all surgery. Patients alternately had palatoplasty with or without IVV. One speech pathologist conducted all perceptual speech and language evaluations without knowledge of the surgical procedure when the children were 3 years of age. The IVV and non-IVV groups were similar with respect to cleft anatomy, mean age at palatoplasty, and audiograms at 1 and 3 years of age. The findings from a sample of 51 patients were that surgical retropositioning and approximation of the levator muscles during initial palatoplasty (1) did not demonstrably affect the incidence of postpalatoplasty auditory perceptual symptoms of velopharyngeal incompetence; (2) required a significantly longer operating time; (3) were costlier than the control procedure; and (4) did not have greater morbidity than the control procedure. These findings suggest either that there is no beneficial effect of IVV upon postpalatoplasty velopharyngeal competence or that the effect, if present, is of small magnitude.

Audiometry↗

PubMed1989

The use of the Wurtzberg system to facilitate fixation in facial osteotomies.

Results of the use of titanium miniplates for the management of fractures and elective osteotomies in the craniofacial region in 40 patients over the past 24 months are reported. Titanium as a biomaterial, the benefits and liabilities of rigid internal fixation, and the effects of using miniplates upon surgical practice are discussed. Clinical examples are provided to illustrate actual usage of craniomaxillofacial miniplates.

Bone Plates↗