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Biomedical subjects

S R Cohen

Publications and source records attributed to S R Cohen.

At least 37 records · Page 2Linked to original sources
PubMed1999

Craniofacial distraction with a modular internal distraction system: evolution of design and surgical techniques.

The present report summarizes the evolution of design for a modular internal distraction system that is applicable throughout the craniofacial region. Eleven patients (5 boys, 6 girls), whose ages ranged from 4 months to 10 years at the time of distraction, constitute the basis for this study. The clinical indications for distraction were exorbitism with corneal exposure (n = 1), obstructive sleep apnea (n = 4), tracheostomy decannulation (n = 1), severe maxillary hypoplasia with class III malocclusion (n = 3), severe vertical and sagittal maxillary deficiency with anophthalmia (n = 1), and relapse following frontoorbital advancement in a case of rare craniofacial clefting (n = 1). Twenty-two distraction devices were used in these 11 patients. Two initial prototypes were tested (prototype 1 = 8 devices; prototype 2 = 2 devices) until the modular internal distraction system (MIDS, Howmedica-Leibinger, Inc.) was developed (n = 12 devices). The craniofacial osteotomies used were Le Fort III (n = 4), monobloc (n = 3), mandibular (n = 3), Le Fort I (n = 2), and cranial (n = 1). The distraction distances ranged from 11 to 28 mm. One patient undergoing mandibular distraction developed transient swelling in the left mandibular region, which responded to antibiotics. There were no other complications. Depending on the age of the patient and the length of distraction, the distraction gap was allowed to consolidate from 6 weeks to 3 months. The devices were then removed on either an outpatient or a 23-hour-stay basis. The modular internal distraction system permits widespread application of easily customizable, buried distraction devices throughout the craniofacial region.

Child↗
PubMed1999

The use of hydroxyapatite cement in secondary craniofacial reconstruction.

Sixty-one patients underwent secondary craniofacial reconstruction for contour defects using hydroxyapatite cement over a 3-year period (20-month mean follow-up). There were 56 children, aged 2.2 to 18 years (mean, 10.7 years), 21 boys and 35 girls. This is the first series of pediatric patients in whom the use of hydroxyapatite cement has been reported. There were five adults aged 21 to 46 years (mean, 32 years), 3 men and 2 women. Thirty-one patients underwent reconstruction for secondary orbitocranial defects after surgery for synostosis, 7 after surgery for hypertelorism, 10 for posttraumatic skull defects, and 13 for a variety of other facial skeletal defects. There were seven complications (11 percent), ranging from a retained drain to postoperative seromas, all of which required reoperation without loss of the contour correction. All of the complications occurred in the first 18 months of our study. There has been excellent retention of implant volume with no recurrence of contour defects to date. We have not found any visible evidence of interference with craniofacial growth over the study period. We conclude that hydroxyapatite cement is a versatile and safe biomaterial when used for the correction of secondary craniofacial contour defects in children and adults. The coupling of antibiotics with this biomaterial may have applications in the treatment of osteomyelitis.

Adolescent↗
PubMed1999

An anatomic evaluation of the furlow double opposing Z-plasty technique of cleft palate repair.

The aim of this investigation was to examine velar anatomy following the Furlow double opposing Z-plasty in order to analyse the theoretical effects of this technique. Thirty patients with cleft lip and/or cleft palate who underwent primary Furlow palatoplasties between 1989 and 1994 were reviewed. The mean age at the time of surgery was 6.4 months. Evaluation was performed at a mean time of 2.9 years postoperatively, and consisted of oral examination of the position of the velar dimple and measurements of velar dimensions from standard lateral cephalograms. A comparative statistical analysis of velar length (n = 17) and thickness (n = 14) was performed using 2 historical control groups (non-cleft norms and non-Furlow cleft palate repairs). The Furlow procedure produced posterior dimples in 19 of 26 patients adequately rated on oral examination, suggesting successful repositioning of the velar musculature in transverse orientation. The mean velar length was not significantly different from that of norms (being 0.72 mm less), suggesting that the Furlow Z-plasty results in the attainment of near normal velar length. In contrast, the mean velar length was 0.46 mm greater compared to non-Furlow repairs. Although this difference was not statistically significant, it suggests that the Furlow Z-plasty may be more effective in increasing velar length compared to non-Furlow palatoplasty techniques. Velar thickness was significantly greater compared to both norms (P = 0.002) and non-Furlow repairs (P = 0.001). These data suggest that the Furlow double opposing Z-plasty repositions the velar muscles in transverse orientation, and increases both velar length and thickness, lending weight to the theoretical effects of this procedure. The anatomic basis of these changes and their functional implications are discussed.

Cephalometry↗
PubMed1999

The role of distraction osteogenesis in the management of craniofacial disorders.

Since its introduction in the medical literature in 1992 by McCarthy, distraction osteogenesis of the craniofacial skeleton has become a standard surgical therapy. The present report attempts to trace the development of craniofacial distraction from the perspective of one of the early proponents of the technique. Although the earliest application of distraction was in children with severe unilateral or bilateral mandibular deficiency, its use for functional abnormalities such as apnoea were especially appealing. Distraction osteogenesis for the midface began with external appliances that were attached to the teeth. Newer, buried devices have eliminated the need for external devices in all LeFort III and monobloc cases. For LeFort I and mandibular cases, the ideal internal device has not been manufactured.

Child↗
PubMed1998

Activity of the soft gelatin formulation of saquinavir in combination therapy in antiretroviral-naive patients. NV15355 Study Team.

OBJECTIVE: A Phase II, open-label, randomized, parallel-arm, multicentre trial to compare the antiviral activity and safety of two formulations of saquinavir (SQV), soft gelatin (SQV-SGC) and hard gelatin (SQV-HGC) capsules, in combination with two nucleoside reverse transcriptase inhibitors (NRTI), in antiretroviral-naive, HIV-1-infected individuals. PARTICIPANTS: A total of 171 people of > or = 13 years, with plasma HIV-1 RNA levels > or = 5000 copies/ml, who had received no protease inhibitor therapy, < or = 4 weeks NRTI therapy and no antiretroviral treatment within 28 days of screening. Eighty-one people were randomized to the SQV-HGC group and 90 to the SQV-SGC group. A total of 148 patients completed 16 weeks of therapy. INTERVENTION: Therapy for 16 weeks with either SQV-SGC 1200 mg or SQV-HGC 600 mg, both three times a day, in combination with two NRTI. RESULTS: Using an on-treatment analysis, patients taking SQV-SGC had a larger reduction in plasma HIV-1 RNA than those taking SQV-HGC (-2.0 versus -1.6 log10 copies/ml). Eighty per cent of those on SQV-SGC had < 400 copies HIV RNA/ml, compared with 43% in the SQV-HGC group (P = 0.001). A statistically significant difference in the area under the curve (AUC) values between the SQV-SGC and SQV-HGC arms (-1.7 versus -1.5 log10 copies/ml, respectively; P = 0.0054) was observed when withdrawals prior to week 12, major protocol violators and patients with < 75% compliance were excluded from the analysis; however, the difference between the values for the intent-to-treat population was not significant (P = 0.1929). Adverse events (mostly mild) included diarrhoea and nausea. CONCLUSIONS: SQV-SGC was generally well tolerated and gave significantly more potent suppression of plasma HIV-1 RNA in antiretroviral-naive patients than SQVHGC.

Adolescent↗
PubMed1998

Pemphigus vegetans-Neumann variant associated with intranasal heroin abuse.

Pemphigus vegetans is variant of pemphigus vulgaris accounting for 5% of all patients with pemphigus disorders. We describe a case of pemphigus vegetans-Neumann type associated with intranasal heroin abuse, restricted to the modified mucous membranes. The results of routine histology and direct and indirect immunofluorescence studies confirmed the diagnosis. The patient responded to oral prednisone of 40 mg daily for 1 month, followed by reduction to a maintenance dose of 15 mg daily. A complete remission was sustained for 6 months. The relationship between intranasal heroin use and the development of pemphigus vegetans remains uncertain but appears to be an intriguing possibility in this patient.

Administration, Intranasal↗
PubMed1998

Periumbilical pseudoxanthoma elasticum associated with chronic renal failure and angioid streaks--apparent regression with hemodialysis.

Pseudoxanthoma elasticum (PXE) is a heritable connective tissue disease involving progressive fragmentation and dystrophic calcification of elastic fibers. Periumbilical disease as the exclusive site of cutaneous involvement is most commonly seen in the rare entity termed periumbilical perforating pseudoxanthoma elasticum (PPPXE). Patients with this disorder are generally obese, middle aged, multiparous black women with hypertension. The cutaneous lesions are well-demarcated, hyperpigmented, periumbilical plaques with keratotic papules on the periphery. Extracutaneous manifestations have rarely been described. We describe a patient with periumbilical PXE associated with chronic renal failure and bilateral angioid streaks. Histopathologic examination demonstrated typical calcification of elastic fibers with additional amorphous calcium deposits in the superficial dermis. Transepidermal elimination was not present. Normalization of the serum calcium-phosphate product resulted in regression of the lesions--both clinically and histopathologically. The relation between PPPXE and hereditary PXE is discussed. The role of chronic renal failure in precipitating PPPXE is considered.

Aged↗
PubMed1998

Skeletal expansion combined with soft-tissue reduction in the treatment of obstructive sleep apnea in children: physiologic results.

Twenty consecutive children, ranging in age from 6 days to 18 years, were treated with skeletal expansion, in addition to soft-tissue reduction, for medically refractory obstructive sleep apnea. The underlying diagnoses were craniofacial microsomia (n = 6), Down syndrome (n = 3), Pierre Robin syndrome (n = 3), cerebral palsy (n = 3), Nager's syndrome (n = 1), Treacher Collins syndrome (n = 1), cri du chat syndrome (n = 1), juvenile rheumatoid arthritis (n = 1), and temporomandibular joint ankylosis (n = 1). Fourteen children had severe medically refractory sleep apnea and were tracheostomy candidates; in the remaining six, tracheostomies were placed shortly after birth and could not be decannulated. Overnight, 12-channel polysomnography was obtained before and after surgery. The mean apnea index improved from 7.42 to 1.26, the mean respiratory disturbance index improved from 25.24 to 1.72, and the mean lowest apnea-related oxygen saturation improved from 68% to 88%. Of the 14 children with medically refractory obstructive sleep apnea, two required tracheostomies. Of the six patients with tracheostomies, five have been decannulated at the time of this writing. Skeletal expansion in conjunction with soft-tissue reduction in the pediatric population permits substantial increases in the volume of both the nasopharynx and oropharynx. Creative use of conventional osteotomies and the application of distraction osteogenesis have enabled surgeons to apply maxillofacial and craniofacial techniques in treating children with obstructive sleep apnea.

Adolescent↗
PubMed1998

Endoscopic surgical treatment for congenital muscular torticollis.

Muscular torticollis, if untreated, may result in significant permanent craniofacial deformities. Surgical release of the sternocleidomastoid muscle is recommended for patients who fail to respond to physical therapy. Current surgical techniques all leave noticeable scars, and provide limited exposure. These limitations make complete muscular release and visualization of the spinal accessory nerve difficult. We have applied a new technique of endoscopic release of the sternocleidomastoid muscle in 12 infants and children ages 4 to 18 months and one adolescent with muscular torticollis. Complete muscular release was achieved in all patients with one minor complication. The spinal accessory nerve was preserved in all cases. Our endoscopic approach allows precise division of the muscle fibers and preservation of neurovascular structures, leaving an inconspicuous scar in the scalp.

Adolescent↗
PubMed1998

Mandibular distraction osteogenesis in the treatment of upper airway obstruction in children with craniofacial deformities.

Over the past 3 years, 16 patients (12 males, 4 females) have undergone mandibular distraction osteogenesis in conjunction with soft-tissue procedures to treat medically refractory obstructive sleep apnea. Thirty distraction devices were placed for bilateral distraction in 14 children and unilateral distraction in 2. The mean age of treatment was 4 years and 8 months (range 14 weeks to 12 years and 8 months). Eight of the patients had failed conventional medical and surgical treatment of obstructive sleep apnea and were considered tracheostomy candidates, whereas the remaining eight had tracheostomies placed shortly after birth for upper airway obstruction. These eight children could not be decannulated by standard protocols. The average distraction distance was 25 mm (range 18 to 35 mm). To date, seven of the eight patients with tracheostomies have been decannulated, and one is still in progress. Clinical improvement in the signs and symptoms of sleep apnea and reduction or elimination of preoperative oxygen requirements occurred in seven of the eight children with medically refractory sleep apnea. Twelve-channel polysomnograms were obtained preoperatively and postoperatively in each of the eight patients without tracheostomies. Respiratory disturbance index decreased from a mean of 7.1 to 1.7 after surgery. Lowest oxygen saturation rose from a mean of 0.70 to 0.89 after surgery. Application of mandibular distraction osteogenesis is an important component in the treatment of obstructive sleep apnea and permits mandibular advancement in the younger child. As more experience is gained with distraction osteogenesis in the treatment of children with obstructive sleep apnea, the role of distraction will become better defined.

Airway Obstruction↗
PubMed1998

Applications of endoscopic surgery in pediatric patients.

Although the advent of endoscopic technology is expanding the fields of reconstructive and aesthetic surgery in adults, there have been few reports of the use of this technology in the pediatric population. Because of their minimally invasive nature, yet wide range of exposure, endoscopic techniques have much appeal for this age group. Here we present our experience with endoscopic pediatric plastic surgery. From February of 1995 to August of 1997, 104 patients underwent 139 procedures utilizing 5- and 10-mm endoscopes. There were 58 male and 46 female patients. The mean age at surgery was 5.6 years (range, 3 weeks to 19 years). The most common type of procedures performed were insertion of tissue expanders (n = 34), excision of benign head and neck masses (n = 27), torticollis release (n = 20), excision of vascular lesions (n = 13), and miscellaneous procedures, (n = 10). There were 26 complications in 139 procedures (19 percent). Seventeen (65 percent) were in the tissue expander group. The rest were scattered among the groups with other diagnoses. Although there did not appear to be a specific type of complication associated with endoscopy, 77 percent occurred in the first 2 months of our study. This suggests a relatively steep technical learning curve. These results demonstrate that endoscopic techniques are eminently applicable in the pediatric population, providing the benefits of small and remote incisional wounds, with complication rates that are comparable with those of conventional open surgical treatment.

Adolescent↗
PubMed1998

Sleep apnea surgery versus tracheostomy in children: an exploratory study of the comparative effects on quality of life.

Successful surgery for medically refractory obstructive sleep apnea in children has prevented tracheostomy in many cases. However, sleep apnea surgery requires postoperative ventilatory support and intensive care, and the magnitude of the surgery may be substantial. Tracheostomy, in contrast, is a simple procedure that is considered the standard of care for relief of upper airway obstruction. To determine their relative benefits, the posttreatment quality of life in children with airway obstruction who underwent either sleep apnea surgery or tracheostomy was evaluated and compared in this exploratory study. A 76-item questionnaire was developed to assess the quality of life in this population, including an investigation of physical symptoms, psychosocial function, and costs. Forty-four parent questionnaires were returned; 16 of these parents had children who had had clinically successful sleep apnea surgery and 6 had children who had had tracheostomies placed for obstructive sleep apnea. Results revealed that the parents of children in the tracheostomy group ranked 95 percent of all items on the questionnaire as worse than the parents of children in the surgery group. These rankings included statistically significant group differences (p < 0.05) on number of hospital, emergency room, and physician visits, and hours per day spent on their child's respiratory care. In addition, parents of the successful sleep apnea surgery group reported significant improvement (p < 0.05) in 100 percent of symptom variables (i.e., choking, snoring, and daytime sleepiness), 75 percent of parental care variables (i.e., assisting with their child's breathing, suctioning), 67 percent of medical visit items, and 75 percent of the stress and coping variables (i.e., perception of child's distress, worrying about their child's breathing, level of family stress), indicating substantial gains in quality of life. Despite initially higher costs, successful surgery for obstructive sleep apnea was associated with substantial benefits in quality of life, health, and psychosocial outcomes when compared with tracheostomy.

Adaptation, Psychological↗
PubMed1998

Two-piece occlusion rim for screw-retained implant prosthesis.

The record base for a multiple, implant-supported, fixed prosthesis may be attached to the implants by screws. The screw attachment provides a stable record base for recording maxillomandibular relationships. Extraoral adjustment of the occlusion rim requires that it be unscrewed to allow removal from the mouth. The rim must be reattached with screws for the next intraoral evaluation. Although this cycle of removal and replacement provides stability, retention, and accuracy, it is time-consuming and inefficient. To resolve this problem, a two-piece record base/occlusion rim can be used. The screw-retained record base remains intraoral for the duration of the clinical appointment. The occlusion rim is designed to fit over the record base, with retention and stability, without screw retention. Use of the two-piece record base/occlusion rim facilitates convenient removal, adjustment, and replacement of the occlusion rim.

Dental Prosthesis, Implant-Supported↗
PubMed1998

Multiple suture synostosis and increased intracranial pressure following repair of single suture, nonsyndromal craniosynostosis.

OBJECTIVE: Increased intracranial pressure, frequently associated with closure of multiple cranial sutures, has been reported to occur in 36% of cases following correction of syndromal craniosynostosis. Although much less common, multiple suture closure may occur following repair of single suture, nonsyndromal craniosynostosis and we present cases that concern two such children. RESULTS: Two children with nonsyndromal craniosynostosis, one metopic and one left-coronal, underwent fronto-orbital advancement at age 3 months. At age 19 months and at age 5 years, respectively, both patients re-presented with headaches, decrease in head circumference percentile, and acceptable cosmetic outcome. Both had computerized tomographic evidence of multiple closed cranial sutures and increased intracranial pressure (ICP) (determined by monitoring). Both patients improved following a cranial expansion procedure. CONCLUSION: Delayed closure of multiple sutures and resultant increased ICP may occur following correction of nonsyndromal, single suture craniosynostosis. This may be more likely when the initial suture is contiguous with the facial sutures. Children should be followed for many years following craniosynostosis repair with cranial, neurologic, and possibly funduscopic examinations as well as head circumference measurements to detect delayed closure of cranial sutures.

Age Factors↗
PubMed1998

Intracranial pressure in single-suture craniosynostosis.

In this paper, we review the incidence of increased intracranial pressure in children with single-suture craniosynostosis. The major studies in this area are presented, along with their limitations. A rational treatment plan including multidisciplinary team management is recommended. All patients with proven synostosis should be followed closely, whether or not surgery is chosen. Continued clinical and basic science research are necessary to further clarify the ramifications of asymptomatic elevations of intracranial pressure in these patients.

Child↗
PubMed1998

The differential diagnosis of abnormal head shapes: separating craniosynostosis from positional deformities and normal variants.

The correct differential diagnosis of an abnormal head shape in an infant or a child is vital to the management of this common condition. Establishing the presence of craniosynostosis, which warrants surgical correction, versus non-synostotic causes of head deformity, which do not, is not always straightforward. This paper deals with three groups of abnormal head shape that may cause diagnostic confusion: the spectrum of metopic synostosis; the dolichocephaly of prematurity versus sagittal synostosis; and the differential diagnosis of plagiocephaly. Special emphasis has been placed on the problem of posterior plagiocephaly, in the light of recent evidence demonstrating that lambdoid synostosis has been overdiagnosed. Metopic synostosis presents as a wide spectrum of severity. Although only severe forms of the disorder are corrected surgically, all cases should be monitored for evidence of developmental problems. The dolichocephalic head shape of preterm infants is non-synostotic in origin and is managed nonsurgically. The scaphocephalic head shape resulting from sagittal synostosis requires surgical intervention for correction. Posterior plagiocephaly may be due to unilambdoid synostosis or positional molding, which have very different clinical and imaging features. True lambdoid synostosis is rare. Most cases of posterior plagiocephaly are due to positional molding, which can usually be managed nonsurgically. Regardless of the suture(s) involved, all children with confirmed craniosynostosis should be monitored for increased intracranial pressure and developmental problems.

Bone Diseases↗