Biomedical subjects

M G Grace

Publications and source records attributed to M G Grace.

At least 19 recordsLinked to original sources

PubMed2000

Relationship of intracanal pressure with viscosity of endodontic sealer during warm Gutta-Percha vertical compaction.

OBJECTIVE: To test the association between endodontic sealer viscosity and intracanal pressure during warm gutta-percha vertical compaction. STUDY DESIGN: An artificial tooth model and pressure-sensing apparatus were developed so that reproducible, quantitative measurements could be determined. Intracanal pressure was measured at 3 phases of obturation: cone insertion, heat application, and force application. Samples were randomly assigned to 3 sealer viscosity groups (most viscous, normal, least viscous) and to a no-sealer group. Evaluations were blinded to group assignments (4 groups, 15 samples per group). RESULTS: Differences in intracanal pressure were detected between sealer viscosity groups. The most viscous group had the largest intracanal pressure. Throughout the phases of obturation, intracanal pressure did not remain constant; values at the time of heat application were lower than at cone insertion and force application. CONCLUSIONS: The results indicate that intracanal pressure increases as sealer viscosity is increased, and that intracanal pressure does not remain constant during obturation.

Analysis of Variance↗

PubMed1999

Age and gender differences in temporomandibular joint radiographic findings before orthodontic treatment in adolescents.

OBJECTIVE: The purpose of this study was to determine whether there is a relationship between abnormal temporomandibular joint radiographic findings and age or gender in a sample of young preorthodontic patients. STUDY DESIGN: A total of 491 consecutive patients, aged 9 to 15 years, were referred for orthodontic records. Routine preorthodontic radiographs, including corrected sagittal tomographs, were taken for each patient and viewed by an observer blinded to clinical records. Temporomandibular joint radiographic findings were classified as normal or abnormal. For comparative purposes, the study population was divided into 2 age groups (9-11 years and 12-15 years). RESULTS: Frequency of abnormal findings ranged from 2.4% to 11.5% and was similar for both sides. Temporal component abnormalities correlated with abnormalities of condylar position, joint space, and condylar osseous morphology. The frequency of osseous abnormalities was higher in girls and highest in older girls. CONCLUSIONS: There are significant differences between genders for some temporomandibular joint radiographic abnormalities, and in our study sample the frequency of abnormalities was highest in 12-to-15-year-old girls.

Adolescent↗

PubMed1998

Orthodontists' views of justification for cost of orthognathic surgery.

PURPOSE: This study evaluated whether orthodontists' treatment of patients was influenced by their perception of the justification for the cost of orthognathic surgery. MATERIALS AND METHODS: A survey of 334 Canadian orthodontists was used to determine what factors influenced views of cost justification. RESULTS: Approximately 80%, 49%, and 9% of orthodontists perceived cost of surgery to be justified for severely, moderately, and mildly compromised patients, respectively. Whether the compromise was functional or aesthetic did not particularly affect their views. Least experienced orthodontists were more likely than more experienced orthodontists to perceive cost of surgery as justified for patients with moderate functional compromise (P < .01). Most experienced orthodontists were more likely than less experienced orthodontists to perceive cost of surgery as unjustified for patients with moderate aesthetic compromise (P < .01). Orthodontists who did not believe cost of surgery to be justified for patients with mild or moderate compromise tended to recommend orthognathic surgery less frequently than camouflage orthodontics for borderline surgery patients (P < .05). CONCLUSIONS: The findings suggest that costs may be contained by orthodontists rationing surgery on the basis of severity of facial skeletal malrelationship and perception of justification of cost. Less experienced orthodontists are less likely to contain costs for patients with moderate functional and aesthetic compromise. Most experienced orthodontists are less likely to contain costs for patients with severe functional compromise. Patient satisfaction may be affected by rationing, which affects the treatment approach and thus the outcome.

Adult↗

PubMed1998

Oral acyclovir in prevention of herpes labialis. A randomized, double-blind, multi-centered clinical trial.

OBJECTIVE: A three-center, randomized, double-blind, placebo-controlled acyclovir clinical trial was conducted among Canadian skiers over a 2-year period. STUDY DESIGN: All patients enrolled in the study reported a history of recurrent herpes labialis with a greater-than-50% chance of a sun-induced trigger. There were 239 patients enrolled, and 237 of these were included in the analysis. For a minimum of 3 days and a maximum of 7 days, each patient received 800 mg of oral acyclovir twice daily (1600 mg/day) 12 to 24 hours before exposure to the sun. A minimum of 3 hours of outdoor activity was required each day. RESULTS: No differences were detected in baseline and outcome measures among the centers, and results from all three centers were combined for further analysis. There was no difference in healing rate between the acyclovir and placebo groups for the first 4 days. Patients using acyclovir healed slightly faster on days 5 and 6, and nearly all patients in both the acyclovir and placebo groups were healed by day 7. Adverse events were evenly distributed; no withdrawals were required in either group. CONCLUSION: 800-mg oral acyclovir taken twice a day was not significantly better than a placebo either in effectiveness and prevention of recurrent herpes labialis or in adverse effects.

Acyclovir↗

PubMed1998

Interobserver variability in pediatric radiographic quality assessment.

Programs to monitor radiographic quality have been established in several Canadian provinces. These quality assurance programs depend in part on the evaluation of technical radiographic errors. Interobserver variability in the assessment of these errors reduces the reliability of such information. This study examined the interobserver variability of three dental specialists involved in documenting radiographic technical errors, and the need for retakes following the initial radiographic surveys of 200 children. Observers were trained and calibrated to standardize the evaluation of errors. The overall frequency at which errors were found in bitewing radiographs was consistent with the results of previous studies, but the number of periapical and panoramic technical errors was low. Interobserver variability occurred in the recording of radiographic technical errors, primarily in the recording of bitewing errors. There was also interobserver variability in the ordering of retakes. The interobserver variability in the assessment of radiographic quality could not be eliminated, despite prior observer training. This could indicate that the decision to retake a radiograph may be based on subjective criteria, especially in the absence of clinical information.

Adolescent↗

PubMed1997

Herpes labialis in skiers: randomized clinical trial of acyclovir cream versus placebo.

OBJECTIVE: A randomized, double-blind trial at seven ski sites in Canada and the United States was conducted to compare the effectiveness and the patient tolerance of topically applied 5% acyclovir cream (MAC III formulation) with those of a placebo cream in the prevention of sun-induced herpes labialis lesions. STUDY DESIGN: All subjects had experienced more than three episodes of sun-induced herpes labialis during the previous year. There were 196 subjects enrolled; 5 did not receive medication, and 10 were excluded from the efficacy analysis for protocol violations. There were 191 subjects in the intent-to-treat analysis, and a separate efficacy analysis was done on 181 subjects. Log rank and Fisher exact tests were used in the analysis. RESULTS: There was no difference between the two groups at baseline with respect to any clinical or demographic factor. There was no substantial difference between the groups with respect to adverse experiences (15 for acyclovir; 13 for the placebo). The acyclovir group had significantly fewer lesions (p < 0.01) than the placebo group (21% vs. 40%) during the 4-day follow-up period. CONCLUSION: The acyclovir group was significantly better than the placebo group during the follow-up period. The safety record of the drug was satisfactory; there was no difference between acyclovir and the placebo in side effects or pain. Topically applied 5% acyclovir cream is an effective preventive step for those who are active and exposed to the sun.

Acyclovir↗

PubMed1997

Caremap management for postoperative prostatectomy care at home: a comparative study.

OBJECTIVE: To evaluate early discharge from hospital with community-based care as an alternative to hospital-based care for patients who have undergone transurethral resection of the prostate (TURP). DESIGN: Prospective comparative study. SETTING: A major urban hospital and the urban community. PATIENTS: Of 198 patients who underwent TURP between Jan. 10, 1994 and Sept. 30, 1994, 81, discharged on postoperative day 1, received the caremap method of health care delivery at home. They were compared with 85 patients who were discharged on postoperative day 2 or 3 and received standard hospital-based care. MAIN OUTCOME MEASURES: Readmission to hospital, reuse of health care services, complications and patient satisfaction. RESULTS: Comparison of the 2 groups revealed no significant differences in readmissions to hospital, reutilization of health care services or complications. Following these initial results, the early discharge program was expanded to include all acute care hospitals and the surrounding community. CONCLUSIONS: Postoperative care for TURP can be delivered in the home. A critical success factor was the ability to provide quality care in the community without adverse effects.

Alberta↗

PubMed1996

Stability of maxilla downgrafting after rigid or wire fixation.

PURPOSE: This article compares the long-term outcomes of rigid internal fixation with wire fixation. PATIENTS AND METHODS: In this retrospective study, nine cases of vertical midface augmentation in which rigid fixation was used were compared with 11 cases with wire fixation. One surgeon completed all cases for the rigid fixation group, and another surgeon completed the cases in the wire fixation group. RESULTS: Follow-up was 16 +/- 11 months for the rigid fixation group and 20 +/- 12 months for the wire fixation group. Inferior movement at the anterior portion of the maxilla was 7.0 +/- 2.9 mm with rigid fixation and 4.5 +/- 3.6 mm with wire fixation (P < .05). Postsurgical superior movement (relapse) was 0.4 +/- 0.4 mm with rigid fixation and 2.4 +/- 2.4 mm with wire fixation (P < .01). Inferior movement at the posterior maxilla was 3.1 +/- 0.2 mm with rigid fixation and 2.8 +/- 2.3 mm with wire fixation. Postsurgical superior movement (relapse) was 0.8 +/- 0.4 mm with rigid fixation and 0.5 +/- 2.3 mm with wire fixation, which was not significantly different. CONCLUSION: This comparison showed downgrafting of the maxilla using autogenous bone harvested from the iliac crest and rigid internal fixation to be a predictable and stable procedure.

Adolescent↗

PubMed1996

Post-imaging temporomandibular joint space analysis.

The objective of this study was to develop and test a quantifiable method of temporomandibular (TM) joint space analysis (JSA) unaffected by head rotation. Sixteen female TM joints were imaged using multidirectional axially corrected tomography. Lateral, central and medial image slices were obtained from each joint, traced three times each, and triplicated for drafting. Tracings and draftings were randomized, blinded, and measured manually with digital calipers. Simulated head rotations of +/-10 degrees were applied and the process repeated. Multiple comparisons were done within and between patients by analysis of variance. Based on this study, we found there was no difference for tracing, drafting, and measurement error within and between patients. There were no significant differences between -10, 0, and +10 degrees of head rotation. Our conclusion is that this method for TM-JSA has a high level of reliability as determined by analysis of tracing, drafting, and measurement error for each joint space position and simulated rotation.

Adolescent↗

PubMed1996

Temporomandibular joint radiographic findings in adolescents.

Radiographic findings in temporomandibular joints (TMJ) of asymptomatic adolescents have been reported, probably because such patients are unlikely to undergo routine TMJ radiography. The purpose of this prospective study was to document radiographic findings in TMJ's of adolescents without a history of TMJ dysfunction to determine prevalence of osseous, positional and functional abnormalities. Corrected sagittal TMJ tomographs in closed and open positions from pre-orthodontic records of 498 adolescent patients aged 8 to 15 years old were studied by one observer. Positional, functional or osseous abnormalities were each found in less than 10% of TMJ's. One percent of joints demonstrated marked limited mobility. There was no significant difference between right and left sides. Our results suggest that routine radiography of TMJ's in adolescents is not a useful screening too although longitudinal studies are necessary to determine whether asymptomatic adolescent patients with radiographic abnormalities will develop signs and symptoms of TMJ dysfunction.

Adolescent↗

PubMed1996

Interobserver variability in radiographic interpretation of pediatric dental diseases: a pilot study.

Interobserver variability in radiographic interpretation of dental disease may be a result of clinical bias, education, training, experience or other factors, and may potentially lead to misdiagnosis of disease. Few studies have investigated variability related to dental specialty. The purpose of this pilot study was to determine interob-server variability in radiographic interpretation of pediatric dental diseases using a small number of observers, consisting of a pedodontist, an orthodontist and an oral radiologist. These specialists interpreted initial radiographic surveys of 200 pediatric patients (4.5 to 15.5 years old). The results showed no differences in interpretations of radiographic signs of dental abnormalities except for caries, abnormal primary root resorption due to the eruptive path of a permanent tooth and presence of a congenital/developmental tooth abnormality. These findings will be used to design future studies which will include a larger number of observers from different dental specialties.

Adolescent↗

PubMed1995

Requirements for admission to medical school: how many years of university study are necessary?

OBJECTIVE: To assess whether students admitted to medical school after completing 2 years of undergraduate study performed as well as those admitted after longer periods of undergraduate study in terms of broad patient-care skills measured at the time of graduation. DESIGN: Retrospective study. SETTING: University of Alberta, Edmonton. PARTICIPANTS: Graduates of the classes of 1990 and 1991, of the 226 graduates 133 had entered medical school after 2 years of undergraduate training, 39 after 3 years and 54 after 4 or more years. Eight students had been excluded because they were either transfer students or international students. OUTCOME MEASURES: Objective and subjective assessments of the main clinical rotations (internal medicine, obstetrics and gynecology, pediatrics, psychiatry, radiology and surgery), results of the faculty's final comprehensive examination and of the Medical Council of Canada's Qualifying Examination. RESULTS: The students who had completed 2 years of undergraduate study before medical school were significantly younger than those who had completed 3 years and those who had completed 4 or more years (mean age [and standard deviation (SD)] 20.5 [2.1], 21.5 [2.4] and 25.1 [4.4] years respectively, p < 0.001). They also had a significantly higher mean grade point average (GPA) for the prerequisite courses for admission to medical school than those with 3 years and those with 4 or more years of undergraduate study (8.26 [SD 0.3], 7.95 [SD 0.3] and 7.80 [SD 0.5] respectively, p < 0.001). The overall mean GPA for the best 2 years of undergraduate study did not differ significantly between the three groups. The students with 2 years of undergraduate study had a significantly lower mean score for the pre-entry interview than those who had 4 or more years of undergraduate study (32.1 [SD 7.6] v. 38.3 [SD 8.5], p < 0.001). There were no significant differences between the three groups in the results of any of the subjective or objective outcome measures. CONCLUSION: Students who completed 2 years of undergraduate study before admission to medical school were able to achieve a satisfactory level of competency and maturity by the end of medical school. The 2-year option for entrance into medical school should be reconsidered.

Adult↗

PubMed1995

Neurodevelopmental outcome after neonatal extracorporeal membrane oxygenation.

OBJECTIVE: To determine the neurodevelopmental outcome of neonates who underwent extracorporeal membrane oxygenation (ECMO group) and similarly critically ill newborns with a lower Oxygenation Index who underwent conventional treatment (comparison group), and to determine whether factors such as the underlying diagnosis and the distance transported from outlying areas affect outcome. DESIGN: Multicentre prospective longitudinal comparative outcome study. SETTING: An ECMO centre providing services to all of western Canada and four tertiary care neonatal follow-up clinics. SUBJECTS: All neonates who received treatment between February 1989 and January 1992 at the Western Canadian Regional ECMO Center and who were alive at 2 years of age; 38 (95%) of the 40 surviving ECMO-treated subjects and 26 (87%) of the 30 surviving comparison subjects were available for follow-up. INTERVENTIONS: ECMO or conventional therapy for respiratory failure. OUTCOME MEASURES: Neurodevelopmental disability (one or more of cerebral palsy, visual or hearing loss, seizures, severe cognitive disability), and mental and performance developmental indexes of the Bayley Scales of Infant Development. RESULTS: Six (16%) of the ECMO-treated children had neurodevelopmental disabilities at 2 years of age, as compared with 1 (4%) of the comparison subjects; the difference was not statistically significant. The mean mental developmental index (91.8 [standard deviation (SD) 19.5] v. 100.5 [SD 25.4]) and the mean performance developmental index (87.2 [SD 20.0] v. 96.4 [SD 20.9]) did not differ significantly between the ECMO group and the comparison group respectively. Among the ECMO-treated subjects those whose underlying diagnosis was sepsis had the lowest Bayley indexes, significantly lower than those whose underlying diagnosis was meconium aspiration syndrome. The distance transported did not affect outcome. CONCLUSIONS: Neurodevelopmental disability and delay occurred in both groups. The underlying diagnosis appears to affect outcome, whereas distance transported does not. These findings support early transfer for ECMO of critically ill neonates with respiratory failure who do not respond to conventional treatment. Larger multicentre studies involving long-term follow-up are needed to confirm these findings.

Developmental Disabilities↗

PubMed1995

Radiographic differentiation of osteogenic sarcoma, osteomyelitis, and fibrous dysplasia of the jaws.

UNLABELLED: Biopsy and histopathologic analysis may fail to consistently separate osteogenic sarcoma, osteomyelitis, and fibrous dysplasia. OBJECTIVES: To establish useful radiographic characteristics to differentiate these diseases, an objective preliminary study of radiographs of 30 cases of these diseases was done. STUDY DESIGN: After precisely defining several radiographic characteristics and completing a calibration study, three observers unaware of the diagnosis examined study cases that were randomly ordered. RESULTS: Despite using trained observers and strict criteria, differentiation of the three conditions is difficult on the basis of radiographic features alone. In osteogenic sarcoma, the distinguishing features were: permeative lesion borders, stippled bone pattern, destruction of cortical outlines, perpendicular spiculations of periosteal new bone, destruction of lamina dura, and widening of the entire periodontal ligament space. Presence of sequestra and laminations of periosteal new bone were the most useful distinguishing features in cases of osteomyelitis that otherwise resemble fibrous dysplasia. In fibrous dysplasia, superior displacement of the mandibular canal and a fingerprint bone pattern were pathognomonic. Displacement of the maxillary sinus cortex, alteration of lamina dura to the abnormal bone pattern, and narrowing of the periodontal ligament space were also useful distinguishing features. CONCLUSIONS: Our findings indicate that diagnosis cannot rely on radiographic characteristics alone, although some radiographic findings were more useful than others.

Diagnosis, Differential↗

PubMed1995

Caremap management in low-severity surgery: a comparative trial.

BACKGROUND: Caremap management refers to the management of defined patient groups using multidisciplinary clinical guidelines developed through literature review and expert opinion. STUDY DESIGN: Using a prospective preintervention and postintervention comparison model, this controlled study compared caremap management and traditional treatment in patients undergoing inguinal herniorrhaphy. Preintervention (n = 141) and postintervention (n = 110) groups were compared for hospital length of stay, resource consumption, and outcomes. RESULTS: Patients cared for by caremap management compared with traditional treatment showed a significant reduction in average length of stay (0.6 compared to 1.6 days, p < 0.01). Laboratory testing decreased by 60 percent in the caremap management group relative to traditional treatment (p < 0.01) and standardization of medication profiles was achieved. There were no significant differences in readmission rate, reutilization of health care services, or complications. Patients in the caremap management group indicated a preference for additional length of stay. CONCLUSIONS: Caremap management offers the potential for achieving effective patient care while using resources efficiently. Further evidence is required to demonstrate that caremap management can fulfill the promise of improving health status outcomes in varied types of patients.

Adult↗

PubMed1993

Treatment of intraventricular hemorrhage with tissue plasminogen activator.

The patients with intraventricular hemorrhage (IVH) were treated with recombinant tissue plasminogen activator (rt-PA) injected directly into the lateral ventricles, followed by ventricular drainage. All had a decreased level of consciousness before treatment (Glasgow Coma Scale score 10 +/- 3.4). A total dose between 2 and 12 mg of rt-PA (6.4 +/- 3.3) was administered. For eight patients with aneurysmal IVH, treatment with rt-PA began with two patients the same day as the aneurysm clipping, and the day after with six patients. For a patient with an excision of a ruptured arteriovenous malformation and a patient with IVH resulting from a lateral ventricular catheterization during posterior fossa tumor surgery, treatment with rt-PA started 24 hours after surgery. After an injection of rt-PA, the ventricular drain was closed for 1 hour, followed by alternate-hourly drainage and intracranial pressure (ICP) monitoring. Five patients received a second injection of rt-PA on the second postoperative day, and one patient received a third dose on the third day. Among the eight patients given rt-PA the day after surgery, the volume of external cerebrospinal fluid (CSF) drainage for 24 +/- 8 hours before treatment was 61 +/- 57 ml, and the mean ICP was 22 +/- 5 mm Hg during this same time. Younger age and poorer neurological condition correlated with higher ICP before treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Comparison of intrathecal administration of urokinase and tissue plasminogen activator on subarachnoid clot and chronic vasospasm in a primate model.

Safety and efficacy of the thrombolytic agent urokinase (URO) in the elimination of subarachnoid clot and prevention of chronic vasospasm was compared with tissue-type plasminogen activator (rt-PA) in a blind, randomized placebo-controlled trial. Twenty monkeys were randomly assigned to one of five groups of four. Each group underwent baseline cerebral angiography followed by bilateral craniectomy and experimental subarachnoid hemorrhage. An Ommaya reservoir was inserted on the right side with its catheter placed into the ipsilateral subarachnoid space. Twenty-four hours later, depending upon group assignment, the animals received 100,000 IU URO, 200,000 IU URO, 1 mg rt-PA, 2 mg rt-PA, or the equivalent volume of normal saline (control group). On Day 7, angiography was repeated and the animals were killed. One animal died as a result of complications during the baseline angiography, presumably due to blood loss and prolonged anesthesia, and a replacement animal was obtained. No animals demonstrated any delayed neurological deficits. The study demonstrated that a single intracisternal bolus injection of rt-PA, 2.0 mg in 2 ml sterile water, or URO, 200,000 IU in 2 ml sterile water, 24 hours after induction of experimental subarachnoid hemorrhage in primates, was equally effective in thrombolysing ipsilateral clot, but neither dosage prevented angiographic vasospasm. Vasospasm occurred bilaterally in all groups. Whereas gross subarachnoid clot was found bilaterally in all animals in the placebo group and both smaller-dose URO and rt-PA groups, right-sided subarachnoid clot was virtually absent and left-sided clot reduced in both higher-dose URO and rt-PA groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Incomplete neural deficits in thoracolumbar and lumbar spine fractures. Reliability of Frankel and Sunnybrook scales.

Because neural status is used both as a treatment determiner and outcome measure, a universal, reliable scale is required. Experienced personnel, provided with concise definitions, demonstrated high inter-rater reliability of Frankel and Sunnybrook scales (Pearson correlation coefficients 0.71-0.91), with 94-100% intra-rater agreement. Both scales correspond to total sensory and motor function but are insensitive to walking and bladder function. Frankel's wide clinical use, reliability, and simplicity identify it to be the preferred measurement system until a better alternative is developed. Discussion of neural status must include description of bladder and walking function.

Adolescent↗