Radiographic Length Research Articles

Endodontic working length assessment: Comparison of storage phosphor digital imaging and radiographic film

Objective. This study compared the difference in interpretation of the position of endodontic file tips between two imaging systems: photostimulable storage phosphor luminescence imaging versus radiographic film. Study design. Thirteen patients were selected at random. Preoperative and trial file length radiographs were made with a dual image receptor composed of a Digora Digital Imaging Plate and a piece of Ektaspeed Plus film. Exposure techniques for E-speed film were used. Root length and file length measurements were made from digital images with the Digora system's measuring tools. Measurements were also made on radiographic film with a 7× measuring magnifier. Root length, file length, and their difference were compared for both film and digital images. Results. Differences were found to be less in digital than in film images. Photostimulable storage phosphor luminescence imaging performed similarly to Ektaspeed Plus film for measuring root lengths, but file tip positions (especially of small file sizes) were difficult to visualize with E-speed film. Conclusions. The smaller difference between file tip and root apex found with digital imaging suggests that this technique is more accurate to assess trial file length. This imaging modality for assessing file positions during root canal treatment may be beneficial to the practitioner.

An evaluation of ektaspeed plus film versus ultraspeed film for endodontic working length determination

Thirteen teeth in human cadaver sections were accessed and #15 K-files were placed at various lengths in one root canal of each tooth. Using a positioner to ensure duplicate views, radiographs were taken with both Ultraspeed and Ektaspeed Plus X-ray film. Each of the 26 radiographs was coded and then placed in random order. Six endodontic specialists measured the distance from the file tip to the radiographic apex on each film. The results were analyzed by analysis of variance and Cronbach's generalizability theory. It was found that 94% of the variance in measurements was due to differences among the viewers, whereas 5% was due to a combination of viewers and tooth. Only 1% was due to differences between the two types of film. It was concluded that Ektaspeed Plus film may be used for working length radiographs because it requires only approximately 50% of the radiation needed for Ultraspeed film.

OR 31 Effect of lossy compression on DDI working length radiographs

OR 31 Effect of lossy compression on DDI working length radiographs

Measurements of tooth length in panoramic radiographs. 2: Observer performance.

Observer performance in tooth-length measurements in panoramic radiography has been examined. Sixty-four teeth, evenly distributed between maxillary first molars, second premolars and mandibular first and second premolars, were fixed in plastic moulds. Each cast was radiographed with an Orthopantomograph, twice with steel balls indicating the cusps and apices of the teeth and once without them. One observer measured the radiographic tooth length twice in both radiographs with indicators in order to estimate the true radiographic tooth length and the repositioning error, and twice in the radiographs without indicators. Seven other observers measured the tooth length on the radiographs without indicators, twice applying their own criteria and twice using defined criteria. The accuracy of the tooth-length measurements was calculated by comparing the true radiographic tooth length with the measurements of the seven observers. The intra-observer variation was defined as the difference between two measurements on the same radiograph. The accuracy and the precision of the tooth-length measurements were highly influenced by the observer performance. The mean radiographic tooth length of the seven observers was closer to the true radiographic tooth length when the observers applied the defined criteria. The inter- and intra-observer variation was higher for the measurements of the maxillary teeth (0.3-1.9 mm) compared with the mandibular teeth (0.3-0.9 mm) for most observers. The highest intra-observer variation was found for the palatal root of the maxillary first molar. The intra-observer variation of four observers decreased somewhat when the defined criteria were used; for the other three observers, however, the variation increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Human growth plate development in the fetal and neonatal period

The development of the normal human upper tibial growth plate was studied at autopsy in 46 stillborns and 79 newborns of 20-41 weeks gestational age. During this time period, the histology of this plate evolves from a highly cellular structure with relatively poor columnar organization and matrix development to the well known structure seen later in postnatal life. The thickness of the growth plate, assessed in the area surrounding the longitudinal tibial axis, decreases continuously from 1.15 mm on the 20th week to 0.6 mm on the 38th week. This decrease results from losses of both matrix and cellular components, mostly of the latter. However, the relative fraction of area occupied by the matrix significantly increased (12%) and matrix area per cell increased 1.5 times over the last half of gestation, indicating a maturation process of the plate towards a more matrix-oriented structure with age. In this maturation process the number of cells per unit area does not change and the average size of the cells appears to decrease. Plate thickness does not decrease further in the final 3 weeks of pregnancy and increases in early neonatal life; this has no apparent influence on the tibial growth rate. In the period under study the relative anatomical participation of the upper tibial growth plate decreases from approximately 4% of the radiographic length of the tibia on the 20th week to less than 1% at term. Present data will provide fetal and neonatal growth plate standards needed to obtain a better understanding of this structure during both normal and abnormal conditions.

A clinical evaluation of the Endocater—An electronic apex locator

The purpose of this study was to evaluate the accuracy of an electronic apex locator, the Endocater, in determining the location of the apical constriction or cementodentinal junction (CDJ). Measurements made by the Endocater were also compared with the adjustments recommended by an experienced endodontist. A total of 69 teeth with 99 canals from nine patients were evaluated. The results indicated that the evaluator was 95.8% and the Endocater 67.7% accurate in positioning the probe within +/- 1.000 mm from the CDJ. Thirty-three canals or 34.4% appeared to be clinically acceptable radiographically and no adjustments were deemed necessary by the evaluator. There was a significant difference (p less than 0.003) between the evaluator's ability to adjust the electronically generated file length radiograph to acceptable clinical standards and the Endocater's ability to determine the location of the CDJ. A total of 59 canals (59.6%) of the electronically determined working lengths were beyond the CDJ (n = 99). In 27 canals, the tip of the probe was greater than 1 mm beyond the constriction. Without radiographs to confirm working lengths, many canals in this study would have been overinstrumented. Future research with electronic apex locators is needed before accepting the technique as a substitution for radiographic working length determination.

Late complications after femoral artery catheterization in children less than five years of age

Fifty-eight children who underwent diagnostic femoral artery catheterization before 5 years of age, from 5 to 14 years before the study, were randomly selected from approximately 300 surviving patients undergoing diagnostic femoral artery catheterization at our institution during the interval. Each patient underwent vascular laboratory segmental pressure and waveform examination and arterial duplex scanning, as well as lower extremity bone length radiographs, which were considered positive if the catheterized leg was ≥1.5 cm shorter than the opposite leg. Thirteen children who had only venous catheterization served as controls. No arterial abnormalities were present in the control patients (mean ankle/brachial index, 1.01). Arterial occlusion was present in both limbs of five patients who had bilateral diagnostic femoral artery catheterization and in 14 limbs of 51 patients who had unilateral diagnostic femoral artery catheterization. Thus arterial occlusion was present in 33% of patients (19 of 58) and in 37% of limbs (24 of 65). The mean ankle/brachial index in the catheterized limbs was 0.79. Leg growth retardation was present in four limbs (8%) of 51 children undergoing unilateral diagnostic femoral artery catheterization and in one (8%) control patient. The inverse relationship between ankle/brachial index and leg growth retardation was significant (R = 0.47, p < 0.0005). Only one patient had symptoms of arterial occlusion (claudication), and one patient had symptoms of leg growth retardation (gait disturbance). We conclude that arterial occlusion is common after diagnostic femoral artery catheterization in children less than 5 years of age, but that excellent collateral supply prevents leg growth retardation and/or symptomatic arterial insufficiency in most children. Children having diagnostic femoral artery catheterization should be monitored for arterial occlusion, and those detected should be monitored for leg growth retardation. Arterial repair in the absence of clinical symptoms appears unwarrented.

Rotational displacement of the distal epiphysis of the tibia without fracture

CASE REPORT In October 1085 a heavy Y-year-old girl fell while wearing roller boots injuring the right ankle. The ankle and foot lay 60” externally rotated in relation to the knee but there was no other obvious deformity and little swelling (Fig. 1). There was no wound and no vascular or nerve complication. Radiographs of the right ankle (Fig. 2) showed no fracture and no obvious displacement of the lower epiphysis of the tibia. There was, however, some mismatching of the diameters of the metaphysis and epiphysis as well as some broadening of the space and incongruity between the structures visible in both views. Full length radiographs of the lower leg were not taken as it was clinically apparent that the injury was one of external rotation of the distal epiphysis of the tibia with its attached intact fibula. Under general anaesthesia the foot and ankle were turned easily to the reduced position, there being an audible and palpable click as the fibula snapped back into the fibular notch of the tibia. The reduction was found to be very stable and a toes to knee plaster cast was applied. For 2 weeks she did not bear weight on the right leg and used crutches followed by 2 further weeks in a short leg walking plaster. At 4 weeks the plaster was discarded and radiographs taken (Fig. 3) showed slight ‘beaks’ of bone formation at the metaphyseal margins of the tibia and a layer of periosteal new bone on the lateral aspect of the distal tibia. The girl made a progressive return to normal activities over a few weeks. When reviewed at I.5 months there were no symptoms and no clinical deformity; the foot was in normal rotational relationship to the knee and lower leg. The radiographs were normal.

Electronic determination of root canal length

Root canal length was measured in an experimental model composed of the severed halves of porcine mandibles, using an electronic device for locating the apical foramen. The measurements, each taken independently by two or three observers, were compared with radiographic working length determinations, and with direct visual measurements made after the teeth were extracted. Under the conditions of the experiment, electronic determination of endodontic working length did not compare favorably with radiographic determination of working length.

Styloid process variation. Radiologic and clinical study.

In this study 484 panographic radiographs of hospitalized patients were evaluated in order to ascertain the normal radiographic length of the styloid process; incidence of elongation of the process; incidence of calcification in the associated ligaments; and presence or absence of segmentation. In addition, an attempt was made to correlate objective and subjective clinical findings to radiographic findings. According to methods described, the mean radiographic length of the styloid process of right and left sides was 29.9 mm and 29.5 mm, respectively. Incidence of elongation and calcification was 28%. Elongation and calcification affected the stylohyoid ligaments more frequently than the stylomandibular ligaments. There was no significant correlation of process elongation and calcification to age, or clinical symptomatology.