Re-exposure in cone beam CT of the dentomaxillofacial region: a retrospective study.

METHODS:: In a retrospective cohort study CBCT images of 4986 patients from the patient database from the Department of Oral Radiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany were included and the rate of re-exposures was counted. Patients were stratified into those who received a scan with the small field-of-view CBCT or the large field-of-view CBCT. The effect of patient-related parameters as age and gender was implicated. As a further device-specific parameter, the statistical analysis included whether the selection of the field of view due to the device type had a significant influence on the occurrence of re-exposures. Furthermore, the rescans were analyzed with regard to their causes. RESULTS:: In total, CBCT images of 82 (1.6%) patients had to be repeated. Looking at the two different devices, in 42 (1.3%) patients that received a scan with the large field-of-view CBCT and in 40 (2.3%) patients that received a scan with the small field-of-view CBCT respectively needed a retake. There was no statistically significant correlation between age and gender to retakes. For the small field-of-view-size significantly more retakes were observed than for the large one. With 46% motion artifacts were the most frequent causes for a re-exposure of the patient. CONCLUSIONS:: Gender and age did not have an impact on the occurrence of re-exposures. Patients who received a scan with the small field-of-view CBCT were significantly more often rescanned than those with the large field-of-view CBCT.

Risk factors for tooth loss in middle and older age after up to 10 years: An observational cohort study.

OBJECTIVE: The objective of this research was to identify risk factors for tooth loss in two birth cohorts, quinquagenarians and septuagenarians, after up to 10 years of clinical observation. DESIGN: One hundred and twenty-three participants were recruited from the Interdisciplinary Study of Adult Development (ILSE) and examined at baseline and up to 10 years after. Thirty-nine and 84 participants belonged to the older (OC; born in 1930/32) cohort and younger (YC; born in 1950/52) cohort, respectively. Each participant underwent a dental examination comprising evaluation of the dental status (number of teeth, prosthetic restorations), Plaque Index (PI), Gingival Index (GI), DMF-S, periodontal probing depths (PD) and tooth mobility (TM). Incidence of tooth loss over the study period was calculated for both cohorts as well as for the grouped dental target variables. A logistic regression model for tooth loss (0=tooth present/1=tooth lost) was compiled with possible binary confounders. RESULTS: During the study period (eight years in mean), 1.2 (1.9) and 2.6 (2.6) teeth were lost in YC and OC, respectively, reflecting correspondent loss rates of 5% and 14% (p<0.001). However, primarily TM >1 merged into substantial tooth loss (60% lost). The regression analysis confirmed the bivariate findings. Older age and worse oral health issues were identified as risk factors for tooth loss(p<0.05). CONCLUSIONS: Both quinquagenarians and septuagenarians show relevant tooth loss over a period of up to 10 years but more in septuagenarians. The predominant predictor for tooth loss seems to be greater tooth mobility. With the rising challenges due to aging in several societies, knowing the risks might help clinicians when weighing treatment strategies and should encourage refining preventive measures for older patients.