Comparison of CT scanograms and cephalometric radiographs in craniofacial imaging.

OBJECTIVE: To compare measurements from human skulls and their images from cephalometric radiographs (CR) and computed tomography (CT) scanograms, in order to gauge the potential clinical use of the latter. DESIGN: Based on specific inclusion criteria, including stable centric occlusion, 13 adult skulls were selected from a larger collection. The mandible was taped to the maxilla after securing the occlusion of teeth and condylar seating in the glenoid fossa. Lateral and posteroanterior cephalographs and CT 'scout views' were taken of each skull by standardized methods. Landmarks were identified on skulls and images. OUTCOME MEASURES: Linear measurements were made on all three records; angular measurements only on CR and CT images. Intraclass correlation coefficients (r) were calculated to assess similarity among records. Paired t-tests were used to compare differences between mean measurements. RESULTS: No statistically significant differences were noted between mean angular values on CR and CT views (P > 0.05). The highest correlations were observed for several vertical midline distances between CT and direct skull measures: 0.82 < r < 0.995-greatest for nasion-menton. For sagittal distances, the highest correlation was between the direct measure of condylion-pogonion and its CR image (r= 0.73). Correlations between CR and skull transverse measures were higher (0.46 < r < 0.80) than the corresponding skull vs. CT measures (0.06 < r < 0.38). CT and CR images are 2D slices and projections, respectively, of 3D structures. Vertical CT and skull measures correspond because the CT projection reflects a 1:1 ratio in the midsagittal plane; CT projected lateral images are smaller than the skull measures. The CR image reflects a distortion (approximately 8%) that brings Co-Pg closer to its anatomic distance, inadvertently contributing to better clinical planning, particularly in orthognathic surgery. The pattern of distortion of PA images was in opposite directions for CR and CT views. CONCLUSIONS: Cephalograms and CT scanograms are close in depicting angular relations of structures, but they differ in the accuracy of imaging linear measurements, because the location and size of an object within the imaged 3D structure varies with both records. Logistic and economic considerations favor the use of cephalographs.

Cardiac troponin I in the normal dog and cat.

Cardiac troponin I (cTnI) has proven to be a highly specific and sensitive marker for myocardial cellular damage in many mammalian species. The structure of cTnI is highly conserved across species, and assays for human cTnI (including the one used in the current study) have been validated in the dog. Blood concentrations of cTnI rise rapidly after cardiomyocyte damage, and assay of cTnI potentially may be valuable in many clinical diseases. The purpose of this study was to establish the normal range of cTnI in heparinized plasma of dogs and cats. Forty one clinically normal dogs and 21 cats were included in the study. One to 3 milliliters of blood were collected by venipuncture into lithium heparin vacutainers for analysis of cTnI (Stratusz CS). The range of plasma cTnI concentrations in dogs was <0.03 to 0.07 ng/mL with a mean of 0.02 ng/mL, with the upper tolerance limit (0.07 ng/mL) at the 90th percentile with 95% confidence. In cats, the range was <0.03 to 0.16 ng/mL with a mean of 0.04 ng/mL, and the upper tolerance limit (0.16 ng/mL) at the 90th percentile as well with 90% confidence. This study establishes preliminary normal ranges of plasma cTnI in normal dogs and cats for comparison to dogs and cats with myocardial injury or disease.

Effect of landmark identification on cephalometric measurements: guidelines for cephalometric analyses.

Identification of craniofacial landmarks, particularly condylar anatomy, on the lateral cephalometric radiograph is erratic. The accuracy of recognition is critical for proper diagnosis of malocclusion and for assessing growth and orthodontic treatment. The aim of this study was to evaluate the identification of condylion and other cephalometric landmarks commonly used, or thought to be easily identifiable. A lateral cephalograph was taken on each of 34 adult subjects. Five examiners, three orthodontists, a dental radiologist and a second-year orthodontic resident rated the condyle, along with sella (S), nasion (Na), point A (A), infradentale (I), pogonion (Pog) and menton (Me) as identifiable, non-identifiable and interpreted. In addition, distances between several of these landmarks were measured. The left condyle, subject to less magnification than the right condyle because it is closer to the film, was more identifiable than the right condyle, which had the highest rating as non-identifiable. Among other landmarks, nasion and point A were the least identifiable, Pog and Me the most. Correlation coefficients for measurements between identifiable landmarks (I-Me) were greater than coefficients for distances involving less identifiable landmarks (S-A). Interestingly, linear measurements were less variable than the identification of corresponding landmarks. These findings corroborate the previous conclusions that clearly identifiable (and the least amount of interpreted) landmarks should be used for proper evaluation of dentofacial relationships. They also suggest, on average, precision in landmark identification is more critical for research purposes than in routine clinical cephalomteric measurements, which serve only as a guide to diagnosis.

The stroke impact scale version 2.0. Evaluation of reliability, validity, and sensitivity to change.

BACKGROUND AND PURPOSE: To be useful for clinical research, an outcome measure must be feasible to administer and have sound psychometric attributes, including reliability, validity, and sensitivity to change. This study characterizes the psychometric properties of the Stroke Impact Scale (SIS) Version 2.0. METHODS: Version 2.0 of the SIS is a self-report measure that includes 64 items and assesses 8 domains (strength, hand function, ADL/IADL, mobility, communication, emotion, memory and thinking, and participation). Subjects with mild and moderate strokes completed the SIS at 1 month (n=91), at 3 months (n=80), and at 6 months after stroke (n=69). Twenty-five subjects had a replicate administration of the SIS 1 week after the 3-month or 6-month test. We evaluated internal consistency and test-retest reliability. The validity of the SIS domains was examined by comparing the SIS to existing stroke measures and by comparing differences in SIS scores across Rankin scale levels. The mixed model procedure was used to evaluate responsiveness of the SIS domain scores to change. RESULTS: Each of the 8 domains met or approached the standard of 0.9 alpha-coefficient for comparing the same patients across time. The intraclass correlation coefficients for test-retest reliability of SIS domains ranged from 0.70 to 0.92, except for the emotion domain (0.57). When the domains were compared with established outcome measures, the correlations were moderate to strong (0.44 to 0.84). The participation domain was most strongly associated with SF-36 social role function. SIS domain scores discriminated across 4 Rankin levels. SIS domains are responsive to change due to ongoing recovery. Responsiveness to change is affected by stroke severity and time since stroke. CONCLUSIONS: This new, stroke-specific outcome measure is reliable, valid, and sensitive to change. We are optimistic about the utility of measure. More studies are required to evaluate the SIS in larger and more heterogeneous populations and to evaluate the feasibility and validity of proxy responses for the most severely impaired patients.

Effect of sampling site, repeated sampling, pH, and PCO2 on plasma lactate concentration in healthy dogs.

OBJECTIVE: To characterize the variation in plasma lactate concentration among samples from commonly used blood sampling sites in conscious, healthy dogs. ANIMALS: 60 healthy dogs. PROCEDURE: Cross-sectional study using a replicated Latin square design. Each dog was assigned to 1 of 6 groups (n = 10) representing all possible orders for 3 sites (cephalic vein, jugular vein, and femoral artery) used to obtain blood. Samples were analyzed immediately, by use of direct amperometry for pH, PO2, Pco2, glucose, and lactate concentration. RESULTS: Significant differences in plasma lactate concentrations were detected among blood samples from the cephalic vein (highest), femoral artery, and jugular vein (lowest). Mean plasma lactate concentration in the first sample obtained, irrespective of sampling site, was lower than in subsequent samples. Covariation was identified among plasma lactate concentration, pH, and PCO2, but correlation coefficients were low. CONCLUSIONS AND CLINICAL RELEVANCE: Plasma lactate concentrations differed among blood samples from various sites. A reference range for plasma lactate concentration was 0.3 to 2.5 mmol/L. Differences in plasma lactate concentrations among samples from various sites and with repeated sampling, in healthy dogs, are small. Use of the reference range may facilitate the clinical use of plasma lactate concentration in dogs.

Headgear versus function regulator in the early treatment of Class II, division 1 malocclusion: a randomized clinical trial.

A prospective randomized clinical trial was conducted to evaluate the early treatment of Class II, Division 1 malocclusion in prepubertal children. Facial and occlusal changes after treatment with either a headgear or a Fränkel function regulator are reported. Molar and canine relationships, overjet, intermolar and intercanine distances were measured from casts taken every 2 months, and mounted on a SAM II articulator. Cephalometric radiographs were taken annually. The results indicate that both the headgear and function regulator were effective in correcting the malocclusion. A common mode of action of these appliances is the possibility to generate differential growth between the jaws. The extent and nature of this effect, as well as other skeletal and occlusal responses differ. Treatment in late childhood was as effective as that in midchildhood. This finding suggests that timing of treatment in developing malocclusions may be optimal in the late mixed dentition, thus avoiding a retention phase before a later stage of orthodontic treatment with fixed appliances. However, a number of conditions may dictate an earlier intervention in the individual patient.

Efficacy of outpatient intensive treatment for drug abuse.

OBJECTIVE: Outpatient intensive treatment for drug and alcohol abuse has become an alternative approach to management of substance abuse. We evaluated the efficacy of an outpatient intensive treatment program for crack cocaine; and the impact of psychiatric diagnosis on outcome variables. METHOD: Subjects participating in an outpatient intensive treatment program underwent descriptive testing at entry and at six-month followup. Outcome variables included Addiction Severity Index composite scores and retention in treatment. RESULTS: Subjects demonstrated significant improvement in ASI scales, over time, with an interaction effect of time and scale. Minimal interaction of psychiatric diagnosis and outcome was found. CONCLUSION: Outpatient intensive treatment demonstrated efficacy in reduction of ASI composite scores. Comparison with standard outpatient treatment and inpatient treatment is needed.

Periodontal pocket treatment in beagle dogs using subgingival doxycycline from a biodegradable system. I. Initial clinical responses.

The present study evaluated the clinical response of periodontal pockets in beagle dogs after treatment with a biodegradable delivery system containing 10% doxycycline hyclate (ABDS-D). Eight adult, female beagle dogs had generalized, severe periodontitis with plaque and calculus-laden pockets. In each animal, 3 teeth with multiple pocket sites > or = 4 mm (mean depth = 6.0 mm) associated with attachment loss (mean = 5.4 mm) and which bled on probing (mean score = 2.5) were treated with a single application of either ABDS-D (experimental group) or the delivery system alone without the doxycycline (control group). Residual polymer was removed at day 7. Bioassay of doxycycline in gingival crevicular fluid associated with presence of ABDS-D gave mean levels of bioactivity of approximately 250 micrograms/ml. Levels of bioactive doxycycline were detected for approximately 7 days after ABDS-D removal. Periodontal maintenance consisted of thrice-weekly toothbrushing the treated sites. Clinical responses were evaluated at 2 weeks, and at bi-weekly intervals thereafter for 4 months. Analyses of the data from the control group showed that there was only slight clinical improvement. In contrast, in the experimental group, bleeding on probing and probing depths were significantly reduced from baseline at all post-treatment time points. At 1 month, mean probing depth reduction was 2.4 mm and this was maintained at 4 months (mean reduction = 2.5 mm). These probing depth reductions occurred primarily through gain of clinical attachment which was 2.0 mm at 4 months. Bleeding had been virtually eliminated (mean = 0.2). It was concluded that, for the beagle dogs with severely infected periodontal pockets in this study, treatment with subgingival doxycycline using the delivery system resulted in substantial improvement in periodontal health.