Biomedical subjects

G E Pron

Publications and source records attributed to G E Pron.

11 recordsLinked to original sources

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

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↗

PubMed1994

Facial sensibility in adolescents born with cleft lip after undergoing repair in infancy.

Values for facial sensibility measured in 68 adolescents born with cleft lip who had undergone repair in infancy (39 unilateral cleft patients with a mean age of 17 years and 29 bilateral cleft patients with a mean age of 19 years) were compared to values of 22 noncleft controls (mean age 18 years). Static two-point discrimination results and cutaneous pressure thresholds were similar between controls and cleft patients. Vibratory threshold values were lower in cleft patients, with significant differences (p < 0.05) in the nasolabial and upper lip skin areas. These differences might indicate minor sensory abnormalities of the quickly adapting fibers, differences in the ability of the deformed maxillary bone of cleft patients to conduct impulses, or other potential errors in the vibrometer.

Adolescent↗

PubMed1993

Pediatric facial fractures: evolving patterns of treatment.

This study reviews the treatment of facial trauma between October 1986 and December 1990 at a major pediatric referral center. The mechanism of injury, location and pattern of facial fractures, pattern of facial injury, soft tissue injuries, and any associated injuries to other organ systems were recorded, and fracture management and perioperative complications reviewed. The study population consisted of 137 patients who sustained 318 facial fractures. Eighty-one patients (171 fractures) were seen in the acute stage, and 56 patients (147 fractures) were seen for reconstruction of a secondary deformity. Injuries in boys were more prevalent than in girls (63% versus 37%), and the 6- to 12-year cohort made up the largest group (42%). Most fractures resulted from traffic-related accidents (50%), falls (23%), or sports-related injuries (15%). Mandibular (34%) and orbital fractures (23%) predominated; fewer midfacial fractures (7%) were sustained than would be expected in a similar adult population. Three quarters of the patients with acute fractures required operative intervention. Closed reduction techniques with maxillomandibular fixation were frequently chosen for mandibular condyle fractures and open reduction techniques (35%) for other regions of the facial skeleton. When open reduction was indicated, plate-and-screw fixation was the preferred method of stabilization (65%). The long-term effects of the injuries and the treatment given on facial growth remain undetermined. Perioperative complication rates directly related to the surgery were low.

Accidents, Traffic↗

PubMed1993

Extremity osteosarcoma in childhood: prognostic value of radiologic imaging.

PURPOSE: To evaluate previously described radiologic prognostic factors in extremity osteosarcoma. MATERIALS AND METHODS: In 47 pediatric patients, available images were evaluated for seven prognostic factors at diagnosis and seven additional factors after preoperative chemotherapy. These factors were correlated with histopathologic response and clinical outcome. The association of histopathologic response and outcome was also evaluated. RESULTS: Metastases at presentation and a > 20-cm-diameter soft-tissue mass were predictive of a poor outcome but occurred in few patients. Factors most predictive of < 90% tumor necrosis after chemotherapy included an increase or no change in soft-tissue mass size and increased bone destruction. Although a significant relationship (P < .05) was found between histopathologic response and outcome, no factors predictive of histopathologic response were also predictive of outcome. The accuracy of pathologic response in predicting outcome was 66%. CONCLUSION: Radiologic studies are of only limited use in predicting which patients with extremity osteosarcoma will have a poor response to chemotherapy or a poor outcome, and are not useful in predicting a good response or outcome.

Adolescent↗

PubMed1992

Craniofacial skeletal measurements based on computed tomography: Part I. Accuracy and reproducibility.

Computed tomography (CT) is a useful modality for the management of craniofacial anomalies. A study was undertaken to assess whether CT measurements of the upper craniofacial skeleton accurately represent the bony region imaged. Measurements taken directly from five dry skulls (approximate ages: adults, over 18 years; child, 4 years; infant, 6 months) were compared to those from axial CT scans of these skulls. Excellent agreement was found between the direct (dry skull) and indirect (CT) measurements. The effect of head tilt on the accuracy of these measurements was investigated. The error was within clinically acceptable limits (less than 5 percent) if the angle was no more than +/- 4 degrees from baseline (0 degrees). Objective standardized information gained from CT should complement the subjective clinical data usually collected for the treatment of craniofacial deformities.

Adult↗

PubMed1992

Craniofacial skeletal measurements based on computed tomography: Part II. Normal values and growth trends.

Current diagnosis and surgical correction of craniofacial anomalies would benefit from accurate quantitative and standardized points of reference. A retrospective study was undertaken to define normal values for a series of craniofacial measurements and to evaluate the growth patterns of the craniofacial complex through axial computed tomography (CT). Fifteen measurements were taken from 542 CT scan series of skeletally normal subjects. The measurement values were then divided into 1-year age categories from 1 to 17 years, and into four age groups for those under 1 year of age. The normal range and growth pattern of measurement values for the cranial vault, orbital region, and upper midface are presented. The overall size of the cranio-orbito-zygomatic skeleton reaches more than 85 percent of adult size by age 5 years. The cranial vault grows rapidly in the first year of life but growth levels off early. The upper midface grows at a slower rate in infancy, but continues to grow later in childhood and early adolescence. Knowledge of the differential growth patterns and normal measurement values in the craniofacial region will help improve diagnostic accuracy, staging of reconstruction, precision of corrective surgery, and follow-up of patients.

Adolescent↗

PubMed1992

Growth patterns in the orbital region: a morphometric study.

Data for analysis of age-related changes in growth in the intercanthal (en-en) and biocular (ex-ex) widths were obtained from 1,594 healthy North American Caucasians in age groups from 1 to 18 years, divided equally between males and females. At 1 year, the degree of development of the intercanthal width reached 84.1%, and that of the biocular width 85.9% of adults in both sexes. The levels of growth achieved by 5 years of age rose to 93.3% in the intercanthal width and 88.1% in the biocular width, in both sexes. The average total growth increments achieved between ages 1 and 18 years were 5.2 mm in the intercanthal width and 12.5 mm in the biocular. The intercanthal width showed very little growth after 1 year of age; in contrast, the biocular width showed significantly greater growth increments both before and after 5 years of age. Rapid growth was observed between 3 and 4 years in the intercanthal width of both sexes. The age-related growth observed in the biocular width was small but continuous up to maturation time. The intercanthal width reached full maturation at 8 years in females and 11 years in males, and the biocular width at 13 years in females and 15 years in males.

Adolescent↗

PubMed1992

Growth patterns of the nasolabial region: a morphometric study.

Age-related growth changes in the nasolabial region were analyzed through six measurements taken between 1 year and 18 years of age in 1,593 North American Caucasians. By 1 year of age, the length of the cutaneous portion of the upper lip and the width of the nose showed the highest levels of development compared with their adult size, 80.3 and 79.5%, respectively. By 5 years, the developmental level of the nasolabial region except nasal tip protrusion approached their maturation level. Our nasal measurements indicated that growth of the nose between 5 and 18 years was significantly greater than that of the upper lip, which revealed significantly greater growth increments between 1 and 5 years of age. The cutaneous upper lip height reached its adult size in 3-year-old females (12.7 mm) and 6-year-old males (14.4 mm). Nose width and height were fully developed in females by age 12 and in males by age 14 or 15. Rapid growth occurred in the upper lip, nose height, and nasal tip protrusion between the ages of 1 and 4 years. Knowledge of these age-related morphologic variations within the nose and upper lip may be useful in planning the time and type of reconstructive surgery and in anticipating further change in the operated regions after the surgical reconstruction.

Adolescent↗

PubMed1988

The reliability of passive smoking histories reported in a case-control study of lung cancer.

A test-retest design has been used to examine the reliability of passive smoking histories reported in personal interviews. A total of 117 control subjects initially interviewed in a lung cancer case-control study conducted in metropolitan Toronto, Canada, between 1983 and 1984 were reinterviewed on average six months later. Responses to initial screening questions used to detect a person's exposure to passive smoke were more reliable for residential than for occupational exposure. Respondents also more reliably reported residential exposure to spouse's passive smoke than to the passive smoke of others at home. Quantitative measures of exposure to passive smoke, i.e., number and duration of exposure, were even less reliably reported. Nonsmoking respondents gave the most reliable information. The low reliability of self-reported duration of exposure to passive smoke is consistent with the inability of several studies to detect a significant dose-response relation with lung cancer risk when measures of dose that depend solely on duration are used.

Data Collection↗

PubMedDate not supplied

Image-guided insertion of the Uldall tunneled hemodialysis catheter: technical success and clinical follow-up.

PURPOSE: To evaluate the technical success, complication rates, and survival time of the Uldall double-lumen catheter placed by interventional radiologists in patients presenting to a hemodialysis clinic. MATERIALS AND METHODS: Patients eligible for this study included those with end-stage renal disease (ESRD) who had failed peripheral vascular access or who were awaiting access at a hemodialysis unit between June 1993 and March 1996. All catheters were placed under fluoroscopic and ultrasound guidance in the angiography suite. RESULTS: Attempts were made to insert 130 catheters into jugular veins in a consecutive series of 61 patients with ESRD. The accumulated catheter experience in this cohort was 15,380 days and the median survival time was 141 days (95% confidence interval [CI]; 116 days-166 days). One hundred twenty-one catheters (93%) were successfully inserted, mainly (94%) into the internal jugular vein. Excellent dialysis blood flow rate was obtained-on average 365 mL/min (95% CI; 350-379 mL/min). The overall infection rate, including exit site (n = 13), sepsis (n = 19), and clavicular osteomyelitis (n = 1), was 2.1 episodes per 1,000 catheter days. CONCLUSIONS: This catheter is recommended for acute and longer term hemodialysis for patients without peripheral vascular access. It can be inserted percutaneously, the same internal jugular vein can be used repeatedly with few complications and good blood flow, and the technique can be easily learned by any experienced angiographer.

Adult↗