Evaluation of the Antimicrobial Functions of N-halamine Dental Unit Waterline Tubing for One Year.

OBJECTIVES: The objective of this study was to test the biofilm-controlling properties of N-halamine antimicrobial dental unit waterline (DUWL) tubing (T) tubing, without recharging over one year, compared to a control line (C). METHODS: A simulated clinical model was used to pump ultrapure water through T and C lines at a rate of 1.4 mL/min, five minutes on, 15 minutes off, eight hours/day, five days a week. Samples of source water, effluent from T and C, and from the stagnant water in the carboy (liquid container) after bench work was completed (S2), were collected aseptically, serially diluted, and cultured on R2A agar for seven days every six weeks. SEM images of the inside surfaces of detached tubing sections were also taken. The carboy was rinsed with a 1:10 dilution of sodium hypochlorite after six months. Means of log transformed CFU values obtained in triplicate were paired by T and C lines across months for comparison by paired Student's t-tests. RESULTS: An increase in effluent and carboy bacterial counts were noted after six months, but decreased after bleach rinse of the carboy. No significant difference (p > 0.25) between T and C lines were observed; similarly, T and carboy were not significantly different (p > 0.30). SEM images showed biofilm attachment on the inside surface of C after two months, but not on T. Organisms identified in the effluent reflected those in the source carboy. CONCLUSIONS: No biofilm attachment was detected on the N-halamine test line after 12 months, indicating its antimicrobial properties were retained. Further evaluation is recommended to determine the optimal recharge interval for N-halamine DUWL tubing when ultrapure source water is used.

Regeneration of periodontal tissues in non-human primates with rhGDF-5 and beta-tricalcium phosphate.

The application of growth factors has been advocated in support of periodontal regeneration. Recombinant human growth and differentiation factor-5 (rhGDF-5), a member of the bone morphogenetic protein family, has been used to encourage periodontal tissue regeneration. This study evaluated the dose response of rhGDF-5 lyophilized onto beta-tricalcium phosphate (bTCP) granules for periodontal tissue regeneration in a baboon model. Periodontal defects were created bilaterally in 12 baboons by a split-mouth design. Plaque was allowed to accumulate around wire ligatures to create chronic disease. After 2 mos, the ligatures were removed, and a notch was placed at the base of the defect. Two teeth on each side of the mouth were randomly treated with bTCP only, 0.5, 1.0, or 2.0 mg rhGDF-5/g bTCP. Animals were sacrificed 5 mos post-treatment, with micro-CT and histomorphometric analysis performed. After 5 mos, analysis showed alveolar bone, cementum, and periodontal ligament formation in all treatment groups, with a dose-dependent increase in rhGDF-5-treated groups. Height of periodontal tissues also increased with the addition of rhGDF-5, and the amount of residual graft material decreased with rhGDF-5 treatment. Therefore, rhGDF-5 delivered on bTCP demonstrated effective regeneration of all 3 tissues critical for periodontal repair.

Oscillometric blood pressure standards for children.

We previously reported blood pressure (BP) readings obtained by the Dinamap (DIN) (Model 8100) were 10 mmHg higher than those obtained by auscultatory methods and thus were not interchangeable. DIN BP data on 7208 schoolchildren ages 5 to 17 were analyzed to generate normative DIN BP standards and to examine the rational for presenting BP standards according to age and height percentiles. Three BP measurements were taken in the sitting position using a BP cuff width 40% to 50% of the circumference of the arm. Boys' systolic pressures (SP) were significantly (p < 0.05) greater (up to 11 mmHg) than those of the girls in subjects age 13 to 17 years. SP levels were most closely correlated with weight (r = 0.595), followed by height (r = 0.560) and age (r = 0.518). When BP levels were adjusted for age and weight, the correlation coefficient of DIN SP with height was negligible (r = 0.026 for boys; r = 0.085 for girls), whereas when adjusted for age and height, the correlation of SP with weight remained high (r = 0.303 for boys; r = 0.216 for girls), indicating that height is not an important independent predictor of BP levels. In conclusion, Dinamap-specific BP standards presented in this report are the only standards that have been generated according to the current BP guidelines recommended by national committees. We found no rational for presenting BP standards according to age and height percentiles.

The effect of enamel matrix proteins on periodontal regeneration as determined by histological analyses.

BACKGROUND: Therapeutic approaches to periodontal regeneration in the past have utilized bone replacement grafts, growth factors, barrier membranes, or combinations of these approaches. More recently, enamel extracellular matrix proteins have been introduced to stimulate periodontal regeneration. One factor thought to have an impact on the outcome of the regenerative process is the initial size of the periodontal defect. This is particularly the case when using proteins to stimulate regeneration, because the concepts of guided tissue regeneration emphasize the need for space maintenance to allow for selected cell repopulation. The goal of this study was to evaluate periodontal regeneration in intrabony defects of various sizes treated with enamel matrix proteins. METHODS: Periodontal defects ranging in size from 1 to 6 mm were created bilaterally around 3 teeth in the mandibles of baboons. Plaque was allowed to accumulate around ligatures placed into the defects. After 2 months, the ligatures were removed, the teeth were scaled and root planed, and a notch was placed at the base of the defect. On one side of the mandible, neutral ethylene diamine tetracetic acid and enamel matrix proteins were used to treat the defects. The other side served as a control, with neutral ethylene diamine tetracetic acid treatment alone after scaling and root planing. Flaps were sutured and the animals were allowed to heal without oral hygiene procedures. After 5 months, the animals were sacrificed and the teeth were processed for histological evaluation. RESULTS: Periodontal regeneration occurred in all sizes of the periodontal defects. Qualitatively, new cementum, periodontal ligament with Sharpey's fibers, and new bone tissue were observed. In general, enamel matrix protein treatment resulted in greater tissue formation than controls. In many instances, dramatic tissue formation occurred far coronal to the base of the defects. In addition, horizontal bone fill occurred in defects that were initially 4 or 6 mm wide. The resultant width of the periodontal ligament was similar in all defects regardless of the original defect width. The cementum width was slightly greater in the wider (4 and 6 mm) defects compared to the more narrow (1 and 2 mm) defects. When evaluating the combined 1 and 2 mm defects, the height of new cementum with enamel matrix protein treatment was 45% greater than the control, with 31% greater new bone height versus the control. In the combined wider defects (4 and 6 mm), new tissue height was more similar between enamel matrix protein-treated defects and control defects. The results from the wider defects must be interpreted cautiously, because the interproximal bone heights were resorbed more adjacent to the wider defects during the plaque accumulation period and likely limited the potential for regeneration. CONCLUSIONS: The treatment of various sized periodontal defects with enamel matrix proteins stimulated substantial periodontal regeneration. In many cases, dramatic amounts of new cementum, Sharpey's fibers, periodontal ligament, and bone tissue were formed far coronal to the notch at the base of the defect, especially considering the width of the original defects. This periodontal regeneration occurred in the absence of exogenous growth factors, bone replacement grafts, barrier membranes, or their combination.

Biologic Width around one- and two-piece titanium implants.

Gingival esthetics around natural teeth is based upon a constant vertical dimension of healthy periodontal soft tissues, the Biologic Width. When placing endosseous implants, however, several factors influence periimplant soft and crestal hard tissue reactions, which are not well understood as of today. Therefore, the purpose of this study was to histometrically examine periimplant soft tissue dimensions dependent on varying locations of a rough/smooth implant border in one-piece implants or a microgap (interface) in two-piece implants in relation to the crest of the bone, with two-piece implants being placed according to either a submerged or a nonsubmerged technique. Thus, 59 implants were placed in edentulous mandibular areas of five foxhounds in a side-by-side comparison. At the time of sacrifice, six months after implant placement, the Biologic Width dimension for one-piece implants, with the rough/smooth border located at the bone crest level, was significantly smaller (P<0.05) compared to two-piece implants with a microgap (interface) located at or below the crest of the bone. In addition, for one-piece implants, the tip of the gingival margin (GM) was located significantly more coronally (P<0.005) compared to two-piece implants. These findings, as evaluated by nondecalcified histology under unloaded conditions in the canine mandible, suggest that the gingival margin (GM) is located more coronally and Biologic Width (BW) dimensions are more similar to natural teeth around one-piece nonsubmerged implants compared to either two-piece nonsubmerged or two-piece submerged implants.

Influence of the size of the microgap on crestal bone changes around titanium implants. A histometric evaluation of unloaded non-submerged implants in the canine mandible.

BACKGROUND: Endosseous implants can be placed according to a non-submerged or submerged approach and in 1- or 2-piece configurations. Recently, it was shown that peri-implant crestal bone changes differ significantly under such conditions and are dependent on a rough/smooth implant border in 1-piece implants and on the location of an interface (microgap) between the implant and abutment/restoration in 2-piece configurations. Several factors may influence the resultant level of the crestal bone under these conditions, including movements between implant components and the size of the microgap (interface) between the implant and abutment. However, no data are available on the impact of possible movements between these components or the impact of the size of the microgap (interface). The purpose of this study was to histometrically evaluate crestal bone changes around unloaded, 2-piece non-submerged titanium implants with 3 different microgap (interface) dimensions and between implants with components welded together or held together by a transocclusal screw. METHODS: A total of 60 titanium implants were randomly placed in edentulous mandibular areas of 5 hounds forming 6 different implant subgroups (A through F). In general, all implants had a relatively smooth, machined suprabony portion 1 mm long, as well as a rough, sandblasted, and acid-etched (SLA) endosseous portion, all placed with their interface (microgap) 1 mm above the bone crest level and having abutments connected at the time of first-stage surgery. Implant types A, B, and C had a microgap of < 10 microns, approximately 50 microns, or approximately 100 microns between implant components as did types D, E, and F, respectively. As a major difference, however, abutments and implants of types A, B, and C were laser-welded together, not allowing for any movements between components, as opposed to types D, E, and F, where abutments and implants were held together by abutment screws. Three months after implant placement, all animals were sacrificed. Non-decalcified histology was analyzed histometrically by evaluating peri-implant crestal bone changes. RESULTS: For implants in the laser-welded group (A, B, and C), mean crestal bone levels were located at a distance from the interface (IF; microgap) to the first bone-to-implant contact (fBIC) of 1.06 +/- 0.46 mm (standard deviation) for type A, 1.28 +/- 0.47 mm for type B, and 1.17 +/- 0.51 mm for type C. All implants of the non-welded group (D, E, and F) had significantly increased amounts of crestal bone loss, with 1.72 +/- 0.49 mm for type D (P < 0.01 compared to type A), 1.71 +/- 0.43 mm for type E (P < 0.02 compared to type B), and 1.65 +/- 0.37 mm for type F (P < 0.01 compared to type C). CONCLUSIONS: These findings demonstrate, as evaluated by non-decalcified histology under unloaded conditions in the canine mandible, that crestal bone changes around 2-piece, non-submerged titanium implants are significantly influenced by possible movements between implants and abutments, but not by the size of the microgap (interface). Thus, significant crestal bone loss occurs in 2-piece implant configurations even with the smallest-sized microgaps (< 10 microns) in combination with possible movements between implant components.

Lower extremity bypass graft revision in diabetics.

Revision of lower extremity bypass graft stenoses identified by surveillance duplex scanning is frequently required in diabetic patients. The authors evaluated (1) the value of routine angiography before graft revision in diabetics, (2) factors that predict patients in whom angiography alters management, and (3) the incidence of recurrent stenosis and factors that might predict it. Forty-two infrainguinal primary vein bypasses undergoing primary revision were retrospectively studied. The initial graft stenosis was detected at a mean of 11.5 +/-3.6 months after the original bypass. Angiograms were obtained in 38 cases, revealing additional findings in 29 of 38 cases (76%), with a resultant alteration of the operative plan in 27 cases (71%). The most frequent additional angiographic finding was the identification or localization of a lesion in the inflow or outflow tracts (18 of 27 cases). Cases where the angiogram altered the management plan had a mean systolic velocity ratio across the stenosis (Vr) of 7.3 +/-6.1, versus a Vr of 4.8 +/-1.3 for cases where the angiogram did not alter the management plan (p<0.04). Duplex scanning identified 4 lesions that were not seen on angiography; 3 of 4 were confirmed as webs at surgery. Twenty of 42 grafts (48%) developed recurrent stenoses at a mean of 4.9 +/-3.8 months from initial revision. Restenosis occurred in 69% of female limbs as compared to 38% of male limbs (p=0.06). Recurrent stenosis was not a predictor of ultimate graft failure, unless left untreated. Four of 10 untreated grafts ultimately failed. A total of 9 of the 42 grafts eventually failed (21%), leading to 3 amputations (7%). The authors conclude that failing infrainguinal bypass grafts identified by duplex in diabetics should undergo a detailed angiographic evaluation. This frequently leads to an alteration in the management plan, especially in the presence of a high Vr across stenoses. High rates of limb salvage (93%) and assisted primary graft patency (79%) despite a high recurrent stenoses rate (48%) justify routine duplex surveillance, preoperative angiography, and aggressive graft revision in diabetic patients with infrainguinal grafts.

Crestal bone changes around titanium implants: a methodologic study comparing linear radiographic with histometric measurements.

Generally, endosseous implants can be placed according to a nonsubmerged or a submerged technique and in 1-piece or 2-piece configurations. Recently, it has been shown that peri-implant crestal bone reactions differ significantly radiographically as well as histometrically under such conditions and are dependent on a rough/smooth implant border in 1-piece implants and on the location of a microgap (interface) between the implant and the abutment/restoration in 2-piece configurations. The purpose of this study was to evaluate whether standardized radiography as a noninvasive clinical diagnostic method correlates with peri-implant crestal bone levels as determined by histometric analysis. Fifty-nine implants were placed in edentulous mandibular areas of 5 foxhounds in a side-by-side comparison in both submerged and nonsubmerged techniques. Three months after implant placement, abutment connection was performed in the submerged implant sites. At 6 months, all animals were sacrificed, and evaluations of the first bone-to-implant contact (fBIC), determined on standardized periapical radiographs, were compared to similar analyses made from nondecalcified histology. It was shown that both techniques provide the same information (Pearson correlation coefficient = 0.993; P < .001). The precision of the radiographs was within 0.1 mm of the histometry in 73.4% of the evaluations, while the level of agreement fell to between 0.1 and 0.2 mm in 15.9% of the cases. These data demonstrate in an experimental study that standardized periapical radiography can evaluate crestal bone levels around implants clinically accurately (within 0.2 mm) in a high percentage (89%) of cases. These findings are significant because crestal bone levels can be determined using a noninvasive technique, and block sectioning or sacrifice of the animal subject is not required. In addition, longitudinal evaluations can be made accurately such that bone changes over various time periods can be assessed. Such analyses may prove beneficial when trying to distinguish physiologic changes from pathologic changes or when trying to determine causes and effects of bone changes around dental implants.

Prevalence of overweight in a triethnic pediatric population of San Antonio, Texas.

OBJECTIVES: To investigate the prevalence of overweight among different ethnic and gender groups of children and adolescents in the San Antonio, Texas, area and to compare the prevalence with that of the US national figures. DESIGN: Cross-sectional study SUBJECTS: A total of 7208 schoolchildren in kindergarten through 12th grade. There were 4215 Mexican American (MA) (58.5%), 2040 non-Hispanic white (NHW) (28.3%) and 953 African American (AA) (13.2%) subjects. MEASUREMENTS: Weight, height and skinfold thicknesses. RESULTS: The body mass index (BMI, kg/m2) values of MA boys were almost consistently and significantly (P<0.05) larger than NHW boys and showed a tendency to be larger than AA boys, beginning as early as age 6 and continuing through age 17. Although rarely significant, a similar trend in ethnic difference was also noted for girls, with the smallest BMI seen in NHW girls. The subscapular skinfold thickness (SST) for MA boys and girls was significantly (P<0.05) larger than that for NHW counterparts and showed a tendency to be larger than AA counterparts. No significant ethnic differences were present in the triceps skinfold thickness (TST) for girls, but MA boys' TST were occasionally larger (P<0.05) than other ethnic-gender groups. Girls' TST were frequently larger (P<0.05) than boys for each ethnic groups. Using the population data from the National Health and Nutrition Examination Survey (NHANES) I as reference, the prevalence of overweight (BMI> or =95th percentile) was greater in MA (15-28%) and AA (11-29%) boys and girls than in NHW (7-17%) counterparts. The combined prevalence of overweight and 'at risk of overweight' (BMI>85th percentile) was much larger in MA boys (40-50%), MA girls (34-52%), and AA girls (33-51%) than other subgroups. The onset of overweight is quite early, starting at 5-6 y of age, especially in girls. Compared to the data from national surveys, the prevalence of overweight found in this study is higher than reported nationally. We found a marked increase in the skinfold thickness, especially SST for boys, but the increase is less for girls. CONCLUSIONS: The prevalence of overweight is higher in MA boys and girls and AA girls than other ethnic-gender groups in the San Antonio, Texas, area. The prevalence of childhood overweight in the San Antonio area is higher than national figures. The findings of increasing prevalence and early onset of childhood overweight are concerning, because these are known risk factors for diabetes and diseases of many other organ systems. Measures to prevent, reduce or treat childhood obesity are urgently needed.

Noninvasive localization of infrainguinal arterial occlusive disease in diabetics.

A retrospective review of 101 diabetics without aortoiliac disease was carried out to analyze the ability of various noninvasive tests to predict the level of significant (>50% stenosis) infrainguinal arterial disease. Patients were studied with anklebrachial indices (ABI), toebrachial indices (TBI), segmental pulse volume recordings (PVR), segmental pressures (SEGP), segmental Doppler waveforms (DWF), and arteriography. Results were classified as normal, disease at the femoropopliteal level, infrapopliteal level, or both levels (multilevel), or noninterpretable. Our findings for the entire study showed that, as a single test, DWF appears to have the best angiographic correlation, although the summed diagnosis of combined DWF and PVR data is superior in distinguishing multilevel disease from isolated tibial disease. SEGP are of very limited use in diabetics, even in multimodality testing, and we no longer include that test in our routine evaluation of diabetics.

Relationships of cortisol, perceived stress, genitourinary infections, and fetal fibronectin to gestational age at birth.

The authors investigated the role of stress and cortisol with patients having preterm labor (PTL) and preterm birth (PTB). The relationships of maternal cortisol, perceived stress, fetal fibronectin (fFN), and genitourinary infections to PTL and PTB were studied. A prospective, longitudinal, observational study (n = 78) was conducted in a private practice in central Texas. Subjects had 4 blood draws for cortisol measurements grouped by 15-19, 20-22, 23-26, 27-30, and 31-35 weeks of gestation. Subjects had 2 vaginal swabs forfFN, chlamydia, and bacterial vaginosis screens at 23-26 and 27-30 weeks with assessment of psychosocial stress at 23-26 and 31-35 weeks. Statistical analysis was by analysis of variance, Pearson correlations, Fisher exact test, and logistic regression. There were no significant differences between the PTB, PTL, and term groups on cortisol levels at any of the gestational periods. Cortisol concentrations at any gestational stage did not correlate with gestational age at birth. A relationship of cortisol to race was observed when comparing Caucasians to other ethnic groups. A correlation (r = 0.42, P < 0.001) between the change in Perceived Stress Scale (PSS) score and gestational age was observed. The greater the decrease in PSS scores, the longer was the gestational age. A significant increase in cortisol at 19-21 weeks (P < 0.04), 23-26 weeks (P < 0.05), and 31-35 weeks (P < 0.01) was observed in patients having genitourinary infection. PTL was also significantly increased in subjects having positive genitourinary infections at either 23-26 weeks or 27-30 weeks (P < 0.01). The sensitivity of fFN to predict PTL collected at 27-30 weeks was 40%, specificity 86%, positive predictive value 55%, and negative predictive value 83%. These results indicate that cortisol is a poor predictor of either PTL or PTB. A decrease in perceived stress during the 2nd trimester was associated with an increase in length of gestation, suggesting the possibility of stress reduction as an appropriate intervention for lengthening gestational age.

The outcome index and system outcome score: a method of quality assurance through outcome analysis in the special care area.

A scoring system intended to assess mortality risk and permit surveillance, evaluation and comparison of medical care was developed in our Surgical Intensive Care Unit. Five simple clinical components were identified and assigned scores according to their statistically validated relationship to mortality and the summation of the component scores resulted in a daily System Outcome Score (SOS). Cluster analysis was used to divide the creation data set of 2,777 patients into suitable groupings of scores to predict mortality and the clustering was confirmed for reproducibility with a validation set of an additional 2,860 patients. Two patient care surveillance techniques were then developed. The first involved the definition of three unfavourable SOS patterns evolving during the course of a patient's admission and detection of one or more of these patterns permits identification of specific patients for whom review of care delivered may be appropriate. The second involves a global assessment of care utilizing the Outcome Index (OI) which relates overall mortality risk in the unit to the actual mortality rate over a given time period. The effectiveness of care can then be compared between different time periods within the one unit or between different units with similar patient mix. A simple menu driven program has been developed for the IBM personal computer and clones that facilitates data storage and retrieval, production of outcome reports and customization of the scoring ranges to meet local standards of performance.

Impact of legal liability, family wishes, and other "external factors" on physicians' life-support decisions.

PURPOSE: The purpose of this study was to determine the impact of external factors on physicians' life-support decisions. "External factors" are those factors that promote the interests of people other than the patient. Examples of external factors include physician legal liability and family wishes about patient care. SUBJECTS AND METHODS: A nationwide sample consisted of 300 randomly selected physician-members from the American Society of Law and Medicine (ASLM) and 300 from the Society for Critical Care Medicine (SCCM); 179 ASLM physicians (60%) and 165 SCCM physicians (55%) responded. A mailed questionnaire presented three cases, each requiring the physician to make a life-support decision. For each case, the physician chose one of several life-support options and rated the importance to his or her decision of specific "decision factors," including some external factors. We assumed the physician would choose the management option supported by the decision factors that the physician considered most important. For this reason, we used discriminant analysis to identify the factors whose importance ratings best predicted management choices. RESULTS: In the first case, 46% of ASLM respondents and 55% of SCCM respondents chose to stop the ventilator of a chronically comatose patient with unknown preferences about life support. Thirty-one percent of ASLM and 27% of SCCM respondents chose to continue the ventilator, and 21% of ASLM and 14% of SCCM respondents chose to apply for a judicial decision. Importance ratings for the external factor, physician legal liability, best predicted management choices. In the second case, 95% of ASLM and 94% of SCCM respondents chose to resuscitate a cancer patient at the patient's request; 3% of ASLM and 4% of SCCM respondents chose no resuscitation. Importance ratings for patient preferences best predicted management choices. In the third case, 38% of ASLM and 35% of SCCM respondents honored a stroke patient's previous refusal of tube feedings, but 59% of ASLM and 62% of SCCM respondents authorized tube feedings in order to secure nursing home placement. Importance ratings for patient preferences best predicted management choices in this case. External factors impacted management choices considerably in the first case and more modestly in the second and third cases. CONCLUSION: External factors impact the life-support decisions of physicians. Physician legal liability may have an especially great impact on these decisions when patients' preferences are not known.

Modified system outcome score and outcome index--method of monitoring patient care in a special care area.

A scoring system intended both to assess mortality risk and permit surveillance, evaluation, and comparison of medical care was developed in our surgical ICU. Five simple clinical indices of organ system failure were selected and weighted according to their statistically validated relationship to mortality, resulting in a daily System Outcome Score (SOS). Cluster analysis was used to divide the creation data set of 2,777 patients into suitable groupings of scores to predict mortality; the clustering was confirmed for reproducibility with a validation set of an additional 2,860 patients. Based on this validation of the scoring system, two computer-controlled patient care surveillance techniques were developed. The first involved the definition of three unfavorable SOS patterns evolving during the course of a patient's admission. Detection of one or more of these patterns, described by the acronym SDL, permits review of the care administered to the specific patient generating the pattern. A global assessment of care is achieved with the Outcome Index (OI), which relates overall mortality risk in the ICU to the actual mortality rate over a given time period. Effectiveness of care can then be compared between different time periods within the one unit or between different units with similar patient mix. The overall system offers the potential for a surveillance-based quality assurance system with widespread applicability.

Correction of density changes caused by methodological errors in CADIA.

Quantitative evaluation of radiographic changes by computer-assisted densitometric image analysis (CADIA) requires exact knowledge about method errors. In the present study, density change errors were determined from pairs of films with "no change". From this distribution of error values, a series of threshold values for correction of changes due to method errors was selected. The threshold values were then applied to results from analysis of densitometric changes in sites with "known loss" or "no change" of the alveolar bone among films from cynomolgus monkeys. The density errors formed non-normal distributions with no difference in magnitudes between the absolute values expressing density decreases and density increases in the same areas. Calculation of sensitivity, specificity, type 1 and type 2 errors showed that these variables were clearly influenced by selection of different threshold values for correction of the density change errors. It is therefore recommended that threshold values be determined for each analytical system initially as well as following any equipment or computer program modification. Before selecting the threshold value for a specific radiographic analysis, the desired level of sensitivity and specificity should be evaluated.