Evaluation of the compatibility of C2, C3, and C4 fractal dimension values with hand-wrist and cervical vertebra maturation methods in determining skeletal maturation.

OBJECTIVES: To examine the correlation between the fractal dimension (FD) values of cervical vertebrae (C2, C3, and C4) and hand-wrist maturation (HWM) and cervical vertebra maturation (CVM) methods. In addition, the correlation between the pubertal growth spurt (PGS) and FD values was examined. METHODS: The lateral cephalometric and hand-wrist radiographs of 120 subjects (61 females and 59 males) aged 8-18 years with a mean age of 13 years, were evaluated retrospectively. The CVM stages were determined in accordance with Hassel-Farman's modification of Lamparski criteria. The HWM stages were determined in accordance with Björk and Grave-Brown criteria. Both HWM and CVM stages were divided into two according to PGS. Fractal analysis of cervical vertebrae was performed according to the White-Rudolph method. The relationships between HWM stages, CVM stages and other variables were evaluated by Spearman's rank-order correlation coefficient. The relationships between FD values, chronological age, and divided stages were evaluated by the Pearson correlation coefficient. The Mann-Whitney U test was used to compare the FD values of two divided stages. RESULTS: There were positive and statistically significant positive correlations between chronological age and both HWM and CVM stages. There was a positive and statistically significant correlation between CVM and HWM stages. In females and total, there were negative and statistically significant correlations between C4 FD values and divided HWM stages, and the differences between C4 FD values of divided HWM stages were also statistically significant. In total, there was a negative and statistically significant correlation between C4 FD values and divided CVM stages, and the difference between C4 FD values of divided CVM stages was also statistically significant. CONCLUSION: The negative correlations found between C4 FD values and divided HWM and CVM stages suggest the fractal analysis of cervical vertebrae, especially of C4, may be used as an objective tool for evaluating the PGS.

Effect of enveloping and disinfection methods on artefact formation on enveloped PSP plate images.

OBJECTIVES: To investigate the artefacts caused by different disinfection and protection methods that can be used for infection control of photostimulable phosphor (PSP) plates. METHODS: The plates that were enveloped with single or double envelopes were sprayed with an alcohol-containing solution or wiped with an alcohol-containing tissue. Four PSP groups with two plates in each group were formed (A = wiping single envelope, B = wiping double envelopes, C = spraying onto single envelope, and D = spraying onto double envelopes). Any artefacts (1 = no artefact, 2 = presence of artefact less than 0.5 cm wide, and 3 = presence of artefact larger than 0.5 cm wide) on the 12 acquired images were evaluated. RESULTS: Artefacts (score-3) occurred on the images of Group C-2 PSP plate after the 3rd exposure. According to the Kruskal-Wallis test the difference between the artefact score of the four methods was found significant. Post-hoc comparisons showed the Group C artefact scores were higher than the others and the difference was significant. The total time of enveloping and disinfection processes for groups was; A = 6.30 min, B = 7.58 min, C = 5.48 min, and D = 7.14 min. CONCLUSIONS: Regardless of the number of envelopes, wiping with a tissue was less likely to cause artefacts, while spraying was reliable only when double envelopes were used. However, using a tissue and double envelopes, which are less risky in terms of artefact, causes time loss, difficulty in manipulation, environmental pollution and high cost.