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 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.

Identification of condylar anatomy affects the evaluation of mandibular growth: guidelines for accurate reporting and research.

Mandibular length is measured on cephalographs to depict changes during growth and after orthodontic treatment, and is often defined between condylion (Co, most posterior superior point on the condylar outline) and pogonion (Pog, most anterior point on the chin). The aim of this study was to assess the accuracy of identifying condylar anatomy, thus the validity of using Co-Pog to evaluate mandibular growth. The sample included 34 children from a prospective study on the early treatment of distoclusions. Two lateral head films were taken of each child, the first with the mouth closed (MC), the second with the mouth open (MO). Three examiners, two orthodontists (U.H. and K.H.) and a dental radiologist (R.B.), rated the condyle as identifiable, nonidentifiable, and interpreted. The rating was applied to the left (L) and right (R) condyles, or to only one outline (O) when the R and L structures appeared superimposed and were not distinguished separately. Besides Co-Pog, the orthodontists traced sella-nasion (SN) and incisor tip-menton (I-Me) to evaluate variability in measurements that do not include Co. One operator (J.G.) measured all distances. Agreement among the three examiners was best in rating the MO radiographs (50%): 4.1% identifiable, 5.9% nonidentifiable or interpreted; in the MC films, they agreed in 32.3% of the cases, but only one of the ratings was identifiable (2.9%). The highest agreement was in identifying the left condyle on the MO film (35.3%). Intraclass correlation coefficients for CO-Pog ranged from r = 0.73 (L side) to r = 0.92 (O) for one orthodontist, and for the other from r = 0.76 (O) to r = 0.85 (L). Both orthodontists had high correlations for SN and I-Me between MC and MO (0.94 < r < 0.98). The variability between examiners in recognizing condylar anatomy, particularly on radiographs taken with the mouth closed, suggests that the identification of condylar anatomy must be rated in studies of mandibular growth. Researchers measuring mandibular length in investigations of mandibular growth after orthodontic therapy should differentiate between cases where the condyle is readily identified, and those where condylar anatomy is interpreted.

Monitoring growth during orthodontic treatment.

The relationship between somatic growth and orthodontic treatment has been limited to the evaluation of body height and skeletal age relative to craniofacial development. The aim of this study was to evaluate the correlation of anthropometric and biochemical measures of general growth with facial and occlusal changes during the early treatment of Class II Division 1 malocclusion. Findings are reported from 46 children, ages 7.20 to 12.85 years (skeletal ages, 5.75 to 12.75 years), who are enrolled in a prospective clinical trial. Body and knee heights were measured monthly, with a Holtain stadiometer and a Knee Height Measuring Device, respectively. Every three months, serum levels were measured of the hormone dehydroepiandrosterone sulfate (DHEAS), an androgen associated with growth in midchildhood, and osteocalcin, an indicator of bone turnover. Significant correlations existed between knee height and various occlusal measurements, but mandibular length was not significantly correlated with knee height and DHEAS levels. Knee height correlated significantly (P < .05) with DHEAS and osteocalcin only in 46% and 37% of the children, respectively. The results indicate that the evaluated biochemical measures, at the time intervals considered, may not increase the accuracy of growth depiction by physical measures alone (height and skeletal maturation).

Initial study of guided tissue regeneration in Class II furcation defects after use of a biodegradable barrier.

This study evaluated guided tissue regeneration in Class II furcation defects after use of a polylactic acid biodegradable barrier in nine patients with mandibular molar defects. Following an initial hygienic phase, surgical flaps were elevated, and the sites were scaled and root planed. Defect perimeter was measured, and a customized barrier (600 to 750 mm thick) that adhered directly to tooth and bone was applied. At baseline, sites were measured for probing depth (6.2 +/- 0.5 mm), gingival margin location (-0.6 +/- 0.6 mm), and attachment level both vertically (6.9 +/- 0.7 mm) and horizontally (5.3 +/- 0.5 mm). Clinically, barriers fragmented and became displaced in 3 to 6 weeks. Substantial granulation tissue was sometimes present between barrier and root surfaces. Six months postsurgery, gingival margin location was close to the presurgical level (-0.4 +/- 0.8 mm). There was clinically and statistically significant improvement in all other parameters: a mean reduction of 3.1 mm in probing depth, a gain of 3.3 mm in vertical attachment level, and a gain of 3.0 mm in horizontal attachment level. These results suggested favorable regenerative outcomes.

Changes of arch width in the early treatment of Class II, division 1 malocclusions.

Changes in arch width during the early correction of Class II, Division 1 malocclusions with either the Fränkel functional appliance or headgear are compared in an ongoing prospective randomized clinical trial. The data were collected from 43 children, ages 7.5 to 12.85 years, who met strict dental and cephalometric criteria for inclusion in the study. They were assigned at random to treatment with either a headgear (n = 21) or a Fränkel appliance (n = 22). Occlusal measurements included the maxillary and mandibular intermolar distances (buccal and palatal/lingual) and intercanine distances. Measurements (millimeters) were performed on casts taken every 2 months, with digital calipers accurate to 0.01 mm. Four months after the initiation of treatment, the mean maxillary intermolar distance was larger in the Fränkel group (palatal: 1.58, SE: 0.22; buccal: 1.58, SE: 0.20) than the headgear group (palatal: -0.39, SE: 0.21; buccal: 0.26, SE: 0.23), and the difference was statistically significant (palatal: p < 0.0001 and buccal: p = 0.0001). The mean maxillary intercanine distance increased more with the headgear (1.62, SE: 0.19) than the Fränkel appliance (0.62, SE: 0.23) p = 0.003. As treatment progressed, the average intermolar distance in the headgear group increased, but was still higher in the Fränkel group by more than 1 mm. The intercanine distance remained larger in the headgear group. The mandibular intermolar and intercanine distances were higher after Fränkel therapy than with headgear.(ABSTRACT TRUNCATED AT 250 WORDS)

Repeated measurement designs with random selections.

We consider repeated measurement designs with a single group as well as with multiple groups. Conventionally, the repeated measurements are made at fixed, often evenly spaced times. The first and second moment conditions needed for an exact F test are not satisfied in general, but with random permutation of the times, a probability measure results that does satisfy these moment conditions, unconditionally. As a consequence, unfortunately, we lose the asymptotic normality that is also essential to justify an F test. We introduce a class of designs and estimators for which both the moment conditions and asymptotic normality are satisfied. The times are the same for all subjects and they are chosen in such a way that they are mutually independent and identically distributed. It is important to understand that our conditions are satisfied only unconditionally--that is, if we do not condition by the randomly chosen times. There is a small probability that the randomly sampled times could be very unevenly allocated. Since we are not conditioning by the times, strictly speaking, this does not matter. It is possible to impose a mild condition of "spread," as we show, at small cost in terms of the P-value. Our method of design makes it possible to do regression analysis, interval estimation, and hypothesis testing on the mean response as a function of time. Because we have mutual independence and identical distributions of times we can form confidence bands.

Clinical efficacy of a dentifrice and oral rinse containing sanguinaria extract and zinc chloride during 6 months of use.

The efficacy of combined use of toothpaste and oral rinse containing sanguinaria extract and zinc chloride was compared to placebo products in a 6-month clinical trial. Sixty subjects with moderate levels of plaque and gingivitis were randomly assigned to active and placebo groups. Noninvasive measures of plaque and gingivitis were assessed at baseline and at 2, 6, 8, 14, 20, and 28 weeks. Bleeding on probing was measured at baseline and 6, 14, and 28 weeks. Active group scores were significantly lower (P less than .0001) than placebo scores at each post-baseline time point for all indices, with the exception of plaque at 2 weeks. The 28 week active group scores were 21% lower than the placebo group for plaque, 25% lower for gingivitis, and 43% lower for bleeding on probing. No dental staining or taste alteration was reported in the active group. Three of 30 active group subjects exhibited minor soft tissue irritations that resolved spontaneously without discontinuation of product use. Results indicate that the test products showed good levels of safety and efficacy when administered in a combined use regimen for 6 months.

Effect of 6 months use of a dentifrice and oral rinse containing sanguinaria extract and zinc chloride upon the microflora of the dental plaque and oral soft tissues.

This study documented the effect upon the oral flora of twice daily brushing with a dentifrice containing 0.075% sanguinaria extract and 2% zinc chloride, followed by use of a mouthrinse containing 0.03% sanguinaria extract and 0.2% zinc chloride. Sixty subjects were randomly assigned to treatment or placebo groups and monitored in a 6-month double-blind clinical trial. Bacteriological samples from the tongue, buccal mucosa, and supra- and subgingival plaque were characterized at 0, 14, and 28 weeks. Microbiological monitoring showed no increases in populations of yeast, staphylococci, coliform organisms, or Pseudomonas. Total Gram-negative counts in supragingival plaque samples decreased 83% in the active group compared to a 232% increase for the control group. Populations of B. intermedius in supragingival plaque were significantly lower in the active group at 3 months and significantly lower counts of Fusobacterium sp. were observed at 3 and 6 months. Results indicate that use of the test products did not promote opportunistic overgrowth of pathogens in the oral flora. Additionally, the alterations in organisms associated with gingivitis may account for reductions in gingivitis seen in the active group.

Influence of parental serum immunoglobulins on morbidity and mortality of beagles and their offspring.

Serum IgA, IgG, and IgM concentrations were determined for Beagle sires and dams of 717 matings to assess the relationship of parental immunoglobulins with the morbidity and mortality of their pups. A significant relationship was not found between parental immunoglobulins and pup mortality. Pups born to dams with low serum IgA (P less than 0.001) and IgM (P less than 0.02) concentrations, however, were found to have an increased incidence of sneezing, coughing, nasal discharge, and conjunctivitis. Thirty-eight percent of pups born to dams with IgA less than or equal to 40 mg/dl developed these same conditions during the first 18 weeks of life, compared with 32% of pups of dams with IgA of 41 to 65 mg/dl and 27% of pups of dams with IgA greater than 65 mg/dl. Similarly, 41% of pups born to dams with low IgM (less than or equal to 135 mg/dl) developed abnormal respiratory tract signs, compared with 34% and 30% of pups born to dams with medium (136 to 175 mg/dl) and high (greater than 175 mg/dl) IgM, respectively. Serum IgA concentrations of the sires were also associated with abnormal respiratory tract signs in pups, but this influence was evident only at 10 to 18 weeks of age. To determine biologic variability of serum IgA, 60 Beagle dams were selected from 3 serum IgA categories, low (10 to 21 mg/dl), medium (60 to 80 mg/dl), and high (125 to 210 mg/dl). A second serum IgA was determined from a sample taken 2 years later.(ABSTRACT TRUNCATED AT 250 WORDS)

New perspectives on Sanguinaria clinicals: individual toothpaste and oral rinse testing.

Clinical studies conducted since 1983 on oral care products containing sanguinaria extract have yielded a variety of results. A careful review of these trials suggests that the designs used to conduct many of these trials may have had affected the study outcomes. Review of these trials suggests that studies testing the efficacy of anti-plaque products exercise the following guidelines: 1) use parallel instead of crossover designs, 2) select appropriate study populations, 3) use sufficient numbers of subjects to ensure statistical power, 4) select appropriate controls, 5) ensure intra- or inter-rater reliability prior to the start of the study, and 6) use proper statistical methodology. This review was undertaken to provide perspective into the results of these early studies, and furnish the rationale for the planning of subsequent clinical testing of sanguinaria-containing products.

Histopathologic and dietary prognostic factors for canine mammary carcinoma.

Histologic and dietary prognostic factors for survival following naturally occurring breast cancer were studied for 145 pet dogs. Information was collected from the dog's owner and veterinarian regarding medical and reproductive history, nutritional status, treatment, tumor recurrence, and length of survival. The usual intake of all dog and table foods consumed 1 year prior to diagnosis was obtained using a validated quantitative food frequency questionnaire. A histologic malignancy score was derived based on 7 histopathologic criteria. The mean age of the dogs was 10.4 +/- 2.5 years; 37% had been ovariohysterectomized prior to diagnosis. Product-limit estimates of survival indicated that 6 factors, namely body conformation 1 year prior to diagnosis (p = 0.03), histologic tumor type (p = 0.004), histologic malignancy score (p = 0.02), histologic invasion (p = 0.002), tumor recurrence (p less than 0.0001), and completeness of surgery (p = 0.01) were of prognostic significance. In addition, when dogs were characterized by the percent of total calories they derived from fat and protein, the median survival time for dogs in the low fat group (less than 39%) with protein greater than 27%, 23-27%, and less than 23% was 3 years, 1.2 years, and 6 months, respectively (p = 0.008). For dogs in the high fat group (greater than or equal to 39%), there was no difference in survival for the different intake levels of dietary protein (p = 0.84). When these data were fitted to a proportional hazards model, recurrence, histologic score, tumor type, percent of calories derived from protein, fat group, and a protein-fat group interaction term were statistically significant. Predicted 1 year survival for dogs on a low fat diet with 15%, 25%, and 35% of total calories derived from protein was 17%, 69%, and 93%, respectively.

Survey of serum IgA, IgG, and IgM concentrations in a large beagle population in which IgA deficiency had been identified.

Concentrations of serum IgA, IgG, and IgM were determined for 829 adult Beagles from a commercial kennel in which several IgA-deficient dogs had been identified previously (index kennel). These values were compared with measurements of 100 adult dogs from another Beagle kennel (control kennel). After adjustment for differences in the ages and gender of the dogs, dogs from the index kennel had significantly (P less than 0.0001) lower IgA concentrations (mean, 46 mg/dl) than dogs from the control kennel (mean, 68 mg/dl). Regardless of kennel, males had significantly (P less than 0.01) higher IgA concentrations than did females. Dogs in the control kennel had significantly (P less than 0.04) higher IgG concentrations (mean, 2,649 mg/dl) than did dogs in the index kennel (mean, 2,478 mg/dl), and female dogs in the control kennel had significantly (P less than 0.05) higher IgM concentrations (mean, 189 mg/dl) than dogs of either sex in the index kennel (mean, 162 mg/dl) or male dogs in the control kennel (mean, 163 mg/dl). For both sexes, concentrations of IgA, IgG, and IgM increased with age.

Cephalometric superimposition on the cranial base: a review and a comparison of four methods.

Spatial change in the jaws of growing persons is often evaluated by superimposing cephalometric tracings made at different points in time. Methods of superimposition vary according to structures used as references within the skull. This study compares four different superimposition methods. The sample consisted of 26 patients (13 boys, 13 girls) treated for Class II, Division 1 malocclusions with extraction of the four first premolars. Tracings of pretreatment (average age for boys, 12.5 years; for girls, 12.2 years) and posttreatment (average age for boys, 15.4 years; for girls, 14.9 years) cephalograms were superimposed according to the following methods: (1) best fit of anterior cranial base anatomy, (2) superimposition on SN line, registered at S, (3) superimposition on registration point R with Bolton-nasion planes parallel, and (4) superimposition on basion-nasion (Ricketts), registered at point CC (4) and point N (4a). Differences in amount of change among the superimposition methods were assessed independently for each of the following landmarks: PNS, ANS, A, B, Pog, Gon. On each patient and for each landmark, ten distances--the paired differences of five posttreatment positions obtained by methods 1, 2, 3, 4, and 4a--were evaluated. Two methods were compared at a time. A t test examined the average difference for each comparison. Because all differences between all paired methods were significant (P less than 0.01), t tests were then viewed under the hypothesis that a difference less than or equal to 1 mm was insignificant clinically. Clinically-statistically significant differences were found only for boys and for the total sample between methods 4a and each of methods 1, 2, and 3. As method 4a is advocated to assess changes of point A (Ricketts), this method gives, for the same person, an interpretation of anterior maxillary change in position different from the other methods. Conclusions about facial changes may be made only in reference to the superimposition method.

Diabetes mellitus and periodontal disease.

A sample of 54 patients with diabetes mellitus were subjects to detailed assessment of periodontal disease levels using standard indices. In order to determine whether the severity of periodontal disease was related to the severity of diabets mellitus, a series of parameters of the diabetes mellitus population was simultaneously studied. There were no significant relationships between the levels of periodontal disease and the duration of diabetes, the type of treatment and the frequency of systemic complications. Periodontal disease in the diabetic appeared to the affected by the same etiologic factors [plaque, calculus, neglect] as would be expected in nondiabetic patients. Further studies with larger population samples would be appropriate.