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Biomedical subjects

J C Posnick

Publications and source records attributed to J C Posnick.

At least 19 recordsLinked to original sources
PubMed1995

Syndrome of proximal interstitial deletion 4p15: report of three cases and review of the literature.

We report on two boys and a girl with interstitial deletion in the short arm of chromosome 4 including the segment p15.2p15.33. All had normal growth with psychomotor retardation, multiple minor congenital anomalies, and a characteristic face distinct from that of the Wolf-Hirschhorn syndrome. One of the patients had congenitally enlarged penis. These patients resemble some of the previously reported patients with similar cytogenetic abnormalities and suggests the recognition of a specific clinical chromosome deletion syndrome.

Abnormalities, Multiple↗
PubMed1995

Monobloc and facial bipartition osteotomies: quantitative assessment of presenting deformity and surgical results based on computed tomography scans.

PURPOSE: The results of monobloc (MB) or facial bipartition (FB) osteotomies on 23 consecutive patients operated on between 1987 and 1991 were evaluated. PATIENTS AND METHODS: A previously described method of clinically relevant linear measurements taken from preoperative and postoperative computed tomographic scans of these patients was used to document their presenting dysmorphology and the results of surgical correction initially and 1 year after operation. These data were compared with control values, and a percentage of normal for each measurement was derived for each patient. RESULTS: In the patients with craniofacial dysostosis undergoing an MB osteotomy, the initial cranial vault length (87% of normal), medial orbital wall length (87%), zygomatic arch length (84%), and extent of globe protrusion (134%) all indicated horizontal (anterior-posterior) deficiency of the upper and middle face. After surgery, these measurements moved closer to age-matched control values. At the 1-year interval a minor degree of relapse was evident. In the patients with craniofacial dysostosis who were believed to need an FB osteotomy, the globe protrusion (142% of normal), medial orbital wall length (85%), and zygomatic arch lengths (83%) all indicated horizontal (anterior-posterior) deficiency in the upper and middle face. In addition, the anterior interorbital distance (123% of normal), mid-interorbital distance (122%), and intertemporal distance (126%) all indicated upper face hypertelorism. As a result of the FB osteotomy, anterior bony projection was achieved, and the hypertelorism was improved, but fell short of age-matched normal values. In the patients with frontonasal dysplasia, cranio-orbital clefting, and isolated orbital hypertelorism who underwent an FB osteotomy, preoperative measurements showed a distinct widening of the whole upper midface with forward projection of the medial relative to the lateral orbital walls. The orbital measurements revealed a substantially widened anterior interorbital distance (175% of normal), increased mid-interorbital distance (123%), and an increased distance between the lateral orbital walls (106%). After the surgical procedure, these measurements were improved and relatively stable but not completely normalized. CONCLUSION: The use of quantitative measurements in the initial evaluation, intraoperative skeletal reshaping, and assessment of early and late reconstructive results provides useful benchmarks.

Acrocephalosyndactylia↗
PubMed1995

The in vivo response of foetal tendons to sutures.

The in vivo response of foetal flexor digitorum profundus tendons to tendon sutures was studied macroscopically and microscopically in foetal lambs. No tendon adhesions were noted at any of the examination intervals. 4 days after injury, a mild inflammatory reaction was noted around the suture. The tendon examined at the 4-week interval showed evidence of migration of epitenon cells from the outer surface of the tendon into the suture track. The tendon examined at the 6-week interval showed normal tendon fibres surrounding the suture site. Differences between foetal skin and foetal tendon healing are discussed along with the possible role of amniotic fluid in modulating the healing process in the foetus.

Animals↗
PubMed1995

The detection and management of intracranial hypertension after initial suture release and decompression for craniofacial dysostosis syndromes.

We performed a retrospective study of 107 consecutive patients with syndromic forms of craniosynostosis (craniofacial dysostosis) seen by the craniofacial team at the Hospital for Sick Children between 1986 and 1992. There were 51 patients with Crouzon's syndrome, 33 with Apert's syndrome, 8 with Pfeiffer syndrome, 11 with Saethre-Chotzen syndrome, and 4 with kleeblättschadel anomaly. Six patients developed raised intracranial pressure (ICP) after initial suture release and decompression (Apert's syndrome, three patients; Pfeiffer syndrome, one patient; Saethre-Chotzen syndrome, two patients). Raised ICP was considered in those children who returned with a bulging fontanelle, progressive frontal bone protrusion, intermittent headaches, irritability, and vomiting. The diagnosis of raised ICP was based on papilledema (four patients), progressive macrocephaly (one patient), and ICP monitoring (one patient). No child in this group had hydrocephalus requiring cerebrospinal fluid diversion. Once raised ICP was detected in these children, a second operation was immediately performed to reduce the ICP with the intention of expanding the volume of the cranial cavity. The second procedures included: anterior cranial vault and upper orbital reshaping (four patients), posterior cranial vault reshaping (one patient), and total cranial vault reshaping (one patient). There were no perioperative complications in these patients, although one patient showed subsequent recurrence of raised ICP requiring further cranial vault re-expansion. At follow-up, ranging from 3 to 7 years, all six patients were asymptomatic without evidence of raised ICP. In our series, raised ICP occurred in 6% of the children with a craniofacial dysostosis syndrome after initial suture release and decompression.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1995

Cranio-orbito-zygomatic measurements from standard CT scans in unoperated Treacher Collins syndrome patients: comparison with normal controls.

Fourteen reproducible cranio-orbito-zygomatic measurements taken from 26 standard axial computed tomographic (CT) scans of unoperated individuals with symmetric forms of Treacher Collins syndrome (TCS) were compared to age-matched controls. The interorbital measurements of the TCS patients were at the mean when compared to their cohort group (medial and lateral orbital wall separation), while the zygomatic measurements were significantly less than normal confirming the extent of malar hypoplasia. The congenitally deficient lateral aspect of the orbits in TCS patients was confirmed by the greater than normal values measured for globe protrusion and medial orbital wall protrusion in conjunction with the diminished lateral orbital wall lengths, all of which use the lateral orbital rim as a reference point. The abnormal shape of the anterior cranial vault in patients with TCS was documented as a diminished intercoronal distance (width) and decreased cephalic length when compared to normal age-matched controls.

Adolescent↗
PubMed1995

Cleft-orthognathic surgery: complications and long-term results.

We reviewed the complications and long-term results of a consecutive series of adolescents (67 males, 49 females; age range 15 to 25 years; mean 18 years) born with a cleft who underwent primary repair in childhood and later developed a jaw deformity and malocclusion that required orthognathic surgery. Between 1986 and 1992, 116 adolescents with either unilateral cleft lip and palate (n = 66), bilateral cleft lip and palate (n = 33), or isolated cleft palate (n = 17) underwent an orthognathic procedure that included a Le Fort I osteotomy; 32 also underwent simultaneous sagittal split osteotomies of the mandible; and 87 underwent osteoplastic genioplasty. Clinical follow-up ranged from 1 to 7 years (mean 40 months) at the close of the study. The preoperative clinical examination varied according to cleft type and individual variation, but all patients had maxillary hypoplasia. Additional cleft-related deformities included residual oronasal fistula and bony defects, clefted alveolar ridges that retained dental gaps, and mobile premaxilla that lacked union to the lateral segments. Overall, 89 percent of residual fistulas underwent successful closure as part of the orthognathic procedure. Surgical cleft dental gap closure was achieved and maintained to the extent planned at 92 percent of the cleft sites. A fixed (prosthetic) bridge was used successfully for dental rehabilitation to close the gap in all other patients at each cleft site (n = 9). All patients with alveolar clefts (n = 99) maintained keratinized mucosa along the labial surface of the cleft-adjacent teeth (n = 264 teeth). Complications were few and generally not serious. There was no segmental bone loss of teeth because of aseptic necrosis or infection. Only 5 percent of cleft adjacent teeth underwent a degree of gingival recession and root exposure as a result of the maxillary osteotomy procedure; all were retained long term. The long-term maintenance of overjet and overbite measured directly from the late (> 1 year) postoperative lateral cephalometric radiograph indicated that 97 percent of patients maintained a positive overjet and 89 percent maintained a positive overbite; 5 percent shifted to a neutral overbite. The methods used to manage jaw deformity, malocclusion, residual oronasal fistula, and bony defects in adolescents born with a cleft are safe and reliable and offer the patient an enhanced quality of life. They also provide a stable foundation in which final soft-tissue lip and nose revisions may be carried out.

Adolescent↗
PubMed1995

Metopic and sagittal synostosis: intracranial volume measurements prior to and after cranio-orbital reshaping in childhood.

This study applied a proven method for obtaining intracranial volume measurements using CT scans to (1) measure the intracranial volume of a consecutive series of children with either metopic or sagittal synostosis prior to any craniofacial procedure, (2) perform a standard cranio-orbital operation in each child, follow them longitudinally, and remeasure their intracranial volume 1 year later, and (3) compare their intracranial volumes with those of an age- and gender-matched cohort and review their cranial growth velocity. The study included 18 children who presented sequentially with untreated isolated nonsyndromic sagittal (n = 8) and metopic (n = 10) synostosis between 1987 and 1990 and who subsequently underwent cranio-orbital reconstruction by the senior author (Posnick) in conjunction with a pediatric neurosurgeon. The primary method of osteotomy and bone-graft fixation varied (i.e., wires, miniplates and microplates and screws). The series included 5 females and 13 males with an average age at the time of operation of 27 months (range 6 to 87 months). The postoperative clinical follow-up ranged from 13 to 47 months at the close of the study. Comparison of our patients' preoperative intracranial volumes with age- and gender-matched volumes available through Lichtenberg showed that 16 of 18 (89 percent) had volumes at or greater than the mean, with 44 percent (7 of 16) exceeding 2 standard deviations above the mean. When comparing our patients' late postoperative volumes with the Lichtenberg normative measurements, 94 percent achieved values at or greater than the mean. All patients achieved increased intracranial volume in association with the surgery performed and the time that lapsed between scan intervals. The majority of our patients (16 of 18) followed an intracranial volume growth curve that closely approximated the norm but with a starting point determined by the preoperative value. Two of 18 followed a growth curve that exceeded the rate of expansion expected for normal children. Our findings suggest that premature closure of either the sagittal or metopic suture does not result in diminished intracranial volume prior to or after the cranio-orbital procedures carried out in childhood. For the majority of the children in our study, both the preoperative intracranial volume and the rate of cranial expansion approximated or surpassed that of children without synostosis. The surgical techniques of skull and upper orbital reshaping with varied forms of osteotomy and graft fixation did not result in a global form of growth restriction. These findings are contrary to standard thinking about the biologic effects of craniosynostosis and raise new questions about our rationale for treatment.

Case-Control Studies↗
PubMed1995

Crouzon and Apert syndromes: intracranial volume measurements before and after cranio-orbital reshaping in childhood.

This study applied a proven method for obtaining intracranial volume (ICV) measurements using computed tomographic scans to document ICVs in children with Crouzon and Apert syndrome before and after cranio-orbital reshaping procedures. Their ICV also was compared with those of an age- and gender-matched cohort and reviewed their rate of cranial expansion. The study included 21 children who presented sequentially with Crouzon (n = 13) or Apert (n = 8) syndrome between 1987 and 1991 and who subsequently underwent a standard first-stage cranio-orbital reconstruction by the senior author (J.C.P.) in conjunction with a pediatric neurosurgeon. The primary method of osteotomy and bone graft fixation varied (i.e., wires, microplates, miniplates, and screws). The series included 16 females and 5 males with an average age at the time of operation of 13 months (range, 6 to 46 months). The postoperative clinical follow-up ranged from 12 to 60 months at the time of the study's completion. Comparison of the IVCs of the Apert patients preoperatively and postoperative with age and gender control volumes showed that six of eight had volumes at least 2 SD above the mean. Postoperatively, the trend continued with all eight patients followed longitudinally; all maintained volumes in excess of 2 standard deviations above the mean. Preoperatively, for the Crouzon children evaluated, 12 of 13 had ICV values greater than the mean. When comparing the patients' postoperative volumes to the normative data, all 13 maintained values at or greater than the mean at the time of their postoperative determination. Ten of the 13 achieved ICVs at or greater than 2 SD above the mean. When reviewing each Crouzon patient's cranial capacity over time, 5 of the 13 approximated the normal growth curve whereas 6 of the 13 exceeded it. This study confirms that Apert patients are macrocephalic before and after standard cranio-orbital procedures carried out in childhood. For the majority of children born with Crouzon syndrome, the cranial capacity will exceed the mean early in life and expand at a rapid rate after cranio-orbital decompression. The biologic explanation for these findings remain unclear.

Acrocephalosyndactylia↗
PubMed1994

Maxillofacial considerations for diagnosis and treatment in Gorlin's syndrome: access osteotomies for cyst removal and orthognathic surgery.

Gorlin's syndrome is a complex hamartomatous/neoplastic syndrome with multisystemic manifestations involving the skin, central nervous system, and bony skeleton. The purpose of this article is to describe how a patient with Gorlin's syndrome was managed with a multipronged approach that included exposure osteotomies for keratocyst removal combined with orthognathic surgery. This case demonstrates the advantages of standard maxillofacial osteotomies to gain access for the removal of odontogenic cysts and benign tumors.

Adult↗
PubMed1994

Nasal dermoid sinus cysts: an unusual presentation, computed tomographic scan findings, and surgical results.

Midline nasal dermoid cysts are congenital lesions resulting from aberrant embryological development. Accurate diagnosis and effective treatment are essential to avoid craniofacial skeletal deformations, cyst rupture, and infection that could cause cutaneous, ocular, or intracranial complications. We report an unusual case of congenital midline nasal dermoid cysts in which an 18-month-old child presented to a hospital emergency department with periorbital cellulitis. It resulted from multiple midline nasal dermoid cysts involving the nasal, forehead, and both orbital regions but without intracranial extension. The patient was successfully managed with a craniofacial approach.

Bone Transplantation↗
PubMed1994

Management of facial fractures in children and adolescents.

The surgical management of facial fractures in children has evolved gradually. Children sustaining facial fractures have not benefited equally as their adult counterparts from the rapid refinements in the management of facial trauma. Only recently have the distinct advantages of accurate primary repair of facial fractures been applied to the rehabilitation of the injured child. The pattern of craniomaxillofacial fractures seen in children and adolescents varies with their evolving skeletal anatomy and socioenvironmental factors. A personal philosophy for the effective management of the craniomaxillofacial injuries that tend to occur in facially traumatized children and adolescents is reviewed.

Adolescent↗
PubMed1994

Ocular manifestations of frontonasal dysplasia.

The ophthalmologic findings associated with frontonasal dysplasia have not been defined previously in a large series of untreated children. We reviewed the ophthalmic manifestations of a series of patients with frontonasal dysplasia who were seen as part of their craniofacial evaluation. All had undergone a complete ophthalmologic examination before any manipulation of either the orbits or the soft tissues of the orbital contents. From 1986 to 1991, 23 patients with frontonasal dysplasia were seen; ophthalmologic abnormalities were found in 20 (87 percent). Abnormalities included significant refractive errors, strabismus, nystagmus, and eyelid ptosis. Three patients had amblyopia, a treatable cause of visual loss, from strabismus or anisometropia. Ten eyes in seven patients (30 percent) had severe structural anomalies, such as optic nerve hypoplasia, optic nerve colobomas, microphthalmia, cataract, corneal dermoid, or inflammatory retinopathy, that resulted in an acuity of 20/100 or worse. The high incidence of ocular abnormalities indicates that early assessment by an ophthalmologist should be part of the initial evaluation of patients with frontonasal dysplasia to detect treatable visual or ocular problems.

Abnormalities, Multiple↗
PubMed1994

Skeletal stability and relapse patterns after Le Fort I osteotomy using miniplate fixation in patients with isolated cleft palate.

We present a series of 14 consecutive isolated cleft palate patients aged 17 to 25 years (mean 19 years) who underwent Le Fort I maxillary advancement fixed with miniplates by the senior author (Posnick) over the period 1987-1991. Ten of the patients underwent autogenous bone grafting; all were stabilized intraoperatively with four miniplates, a prefabricated acrylic splint, and intermaxillary fixation. The patients were analyzed to determine amount and timing of horizontal and anterior and posterior vertical relapse, correlation between advancement and relapse, effect of a pharyngoplasty in place at time of osteotomy, effect of performing multiple jaw procedures, and maintenance of overjet and overbite. Tracings of preoperative and serial postoperative lateral cephalograms (immediate, 6 to 8 weeks, and 1 year) were analyzed to calculate horizontal and vertical maxillary changes and the amount of overjet and overbite maintained. Clinical follow-up ranged from 1.5 to 5.5 years (mean 2.5 years). No significant difference was seen in vertical or horizontal change or relapse between patients who had maxillary surgery alone (n = 10) and those who had operations in both jaws (n = 4), nor did outcome vary significantly for those who had a pharyngoplasty in place (n = 8) at the time of their Le Fort I osteotomy. The mean "effective" maxillary advancement for the group was 6.4 mm, with 5.4 mm maintained 1 year later (mean relapse 1.0 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

An assessment of postnatal growth after in utero long bone osteotomy with fixation.

Researchers have recently suggested that rigid fixation of the immature bony skeleton may restrict growth and development. This study assesses the effect on postnatal growth of an in utero tibial osteotomy fixed with a miniplate in fetal sheep. A midshaft osteotomy was performed on fetal sheep tibia (n = 5) at 95 days' gestation (term 145 days). One tibia was reduced and fixed with a titanium miniplate and screws, while the contralateral hindlimb served as a control. The newborns were vaginally delivered and sacrificed at 2 months of age. The hindlimbs, control and fractured, were harvested, stripped of soft tissue, and the tibia, femur, and distal metatarsal were each measured and weighed. Each tibia also underwent radiographic analysis and histologic examination (after decalcification) using hematoxylin and eosin, Sirius red, and Alcian blue stains. No prenatal, postnatal, or perioperative medical complications occurred. Apart from a slight angulation in one operated tibia, no gross morphologic differences, either visible or palpable, were found between the operated and control limbs. This was confirmed radiographically where no remnant of the osteotomy site was visible. Measurements of the operated and control tibias, femurs, and metatarsal bones were not statistically different. Histologic analysis showed a total incorporation of bone at the osteotomy site with appositional growth present. All bone was lamellar with longitudinal orientation. In the area of the screw sites, the surrounding bone shaft was the same width as its neighboring bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Facial sensibility in adolescents with and without clefts 1 year after undergoing Le Fort I osteotomy.

Static two-point discrimination, pressure, and vibratory threshold values were measured at standard coordinates in the area corresponding to the infraorbital nerve distribution in 59 adolescents 1 year after undergoing LeFort I osteotomy. The patients were divided into three groups: those born with unilateral cleft lip and palate (n = 30; mean age, 18 years; SD = 2); those with bilateral cleft lip and palate (n = 12; mean age, 19 years; SD = 3); and those without a cleft (n = 17; mean age, 19 years; SD = 3). One year after the osteotomy, none of the patients complained of altered sensibility in the maxillary vestibular mucosa, gingiva, or upper lip and cheek regions. No significant differences were found between the mean postoperative sensibility values of patients with and without clefts, indicating that the presence of clefting did not affect sensory recovery. Mean postoperative static two-point discrimination values were higher than preoperative values in all areas tested and in all patient groups. These results suggest that the sensory recovery, although incomplete, was strong enough to mask any subjective feelings of changes in sensory function.

Adolescent↗
PubMed1994

Skeletal stability and relapse patterns after Le Fort I maxillary osteotomy fixed with miniplates: the unilateral cleft lip and palate deformity.

The outcomes of a consecutive series of 35 adults and adolescents judged to be skeletally mature (mean 18 years) who had unilateral cleft lip and palate and had undergone Le Fort I advancement fixed with miniplates were investigated. All patients had received grafts of autogenous iliac bone and were stabilized intraoperatively with four miniplates. The amount and timing of horizontal and vertical relapse, correlation between advancement and relapse, effect of a pharyngoplasty in place at the time of osteotomy, effect of performing multiple jaw procedures, and maintenance of overjet and overbite were analyzed. Tracings of preoperative and serial postoperative lateral cephalograms (taken immediately and at 6 to 8 weeks and 1 year) were analyzed to calculate horizontal and vertical maxillary change and the amount of overjet and overbite maintained. Clinical follow-up ranged from 1.5 to 4.5 years (mean 1.5 years). No significant difference was seen in horizontal or vertical surgical change or relapse between patients who had maxillary surgery alone (n = 24) and those who had operations on both jaws (n = 11), nor did outcome vary significantly for those with a pharyngoplasty in place (n = 13) at the time of their Le Fort I osteotomy (p < 0.05). The mean effective horizontal advancement achieved for the group was 6.9 mm, with 5.3 mm maintained 1 year later (mean relapse of 1.6 mm). The mean effective vertical change of the maxilla was 2.1 mm initially and 1.7 mm 1 year later (mean relapse of 0.4 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Frontonasal and craniofrontonasal dysplasia: preoperative quantitative description of the cranio-orbito-zygomatic region based on computed and conventional tomography.

The unoperated crano-orbito-zygomatic complex of 18 children (mean 4.7 years) with frontonasal dysplasia (FND) and 12 children (mean 1.1 years) with crainofrontonasal dysplasia (CFND) was quantified by 15 standard measurements performed on either computed tomography scans or facial tomograms. The results were compared with age-matched control values. In the FND group, the mean anterior interorbital and mid-interorbital distances were significantly increased at 148% and 118% of normal, and in the CFND patients, at 177% and 140% of normal. Excessive medial orbital wall protrusion (mean, 145% of normal in FND and 177% in CFND), shortened zygomatic arch lengths (mean, 94% of normal in FND and 91% in CFND), and reduced cephalic lengths (mean, 96% of normal in FND and 83% in CFND) were all observed. An expanded interzygomatic buttress distance was documented only in the CFND group, at 11% of normal. The clinical presentation of craniofacial deformities such as FND and CFND can be objectively described by a numerical analysis of the bony pathology.

Adolescent↗