Effect of untreated and treated temporomandibular joint arthritis on mandibular volume development in growing rabbits.

OBJECTIVES: The goal of this work was to investigate the volume development of the mandible in growing rabbits with bilaterally induced temporomandibular joint (TMJ) arthritis that was either left untreated or treated with the tumor necrosis factor-alpha (TNF-α) antagonist etanercept. METHODS: A total of 18 New Zealand White rabbits aged 8 weeks were randomized to three groups of 6 animals each. Two of these groups were used as arthritis groups by sensitizing the 12 animals to ovalbumin (OA) at 10 weeks, followed by intraarticular OA injections to induce bilateral TMJ arthritis and repeating these injections every 3 weeks to maintain the inflammation. One of the two arthritis groups was treated by weekly subcutaneous etanercept injections, whereas the other group was left untreated. The remaining 6 animals served as controls. Maxillofacial CT scans were obtained at 3-week intervals (from week 10 of the rabbits' lives to the end of the experiment at 22 weeks) to volumetrically track the development of the mandibles after segmentation. RESULTS: The mandibles did not grow at a continuous rate, but the rate of development was found to decrease in all groups over the course of the study (weeks 10-22). The most extensive volume increases were noted during weeks 10-13. Severe growth deficiencies, especially of the condylar processes, were observed in the arthritis group not receiving treatment. The arthritis group treated with etanercept showed better rates of growth without, however, reaching the normal range of the control group. CONCLUSION: Antigen-induced TMJ arthritis was found to involve severe problems of growth similar to those in juvenile idiopathic arthritis. Etanercept can improve the volume development but does not reestablish an entirely normal rate of growth.

Investigation of bone conditions for orthodontic anchorage plates in the anterior mandible.

OBJECTIVES: The clinical success of orthodontic anchorage plates depends on the stability of the miniscrews used for fixation. For good stability, the application site must provide bone of good quantity and quality. This study was performed to analyze bone quantity for orthodontic anchorage plates in the anterior mandible. PATIENTS AND METHODS: A total of 51 computed tomography (CT) scans of fully dentate patients (mean age 24.0±8.1 years; 27 men and 24 women) were evaluated. Measurements were taken to analyze the total orovestibular and vestibular cortical thickness of the mandibular jawbone at different anterior locations and levels. RESULTS: Vestibular cortical thickness is generally thinnest within the incisor area on the apex level. Its thickness increases in basal and distal directions. The total orovestibular thickness is also the least on the level of the anterior mandibular apices, becoming thicker toward more basal levels and the posterior teeth. CONCLUSION: We can reasonably assume that the stability of anchorage plates can be optimized by selecting a position well basal to the apices of the lower incisors, as this area offers enhanced cortical and total jawbone thickness.

Size determination and response assessment of liver metastases with computed tomography--comparison of RECIST and volumetric algorithms.

OBJECTIVE: To compare different three-dimensional volumetric algorithms (3D-algorithms) and RECIST for size measurement and response assessment in liver metastases from colorectal and pancreatic cancer. METHODS: The volumes of a total of 102 liver metastases in 45 patients (pancreatic cancer, n=22; colon cancer, n=23) were estimated using three volumetric methods (seeded region growing method, slice-based segmentation, threshold-based segmentation) and the RECIST 1.1 method with volume calculation based on the largest axial diameter. Each measurement was performed three times by one observer. All four methods were applied to follow-up on 55 liver metastases in 29 patients undergoing systemic treatment (median follow-up, 3.5 months; range, 1-10 months). Analysis of variance (ANOVA) with post hoc tests was performed to analyze intraobserver variability and intermethod differences. RESULTS: ANOVA showed significant higher volumes calculated according to the RECIST guideline compared to the other measurement methods (p<0.001) with relative differences ranging from 0.4% to 41.1%. Intraobserver variability was significantly higher (p<0.001) for RECIST and threshold based segmentation (3.6-32.8%) compared with slice segmentation (0.4-13.7%) and seeded region growing method (0.6-10.8%). In the follow-up study, the 3D-algorithms and the assessment following RECIST 1.1 showed a discordant classification of treatment response in 10-21% of the patients. CONCLUSIONS: This study supports the use of volumetric measurement methods due to significant higher intraobserver reproducibility compared to RECIST. Substantial discrepancies in tumor response classification between RECIST and volumetric methods depending on applied thresholds confirm the requirement of a consensus concerning volumetric criteria for response assessment.

Comparison between logopedic and MRI findings in evaluating tongue function.

INTRODUCTION AND AIM: The logopedic examination according to Kittel (1998) is a method frequently used to diagnose tongue dysfunction. There has been a lack of reliable parameters to confirm this analysis. MR images visualize resting position and tongue movement as well as surrounding structures relevant to oral function. The aim of this study was to compare logopedic and MRI findings in evaluating tongue function and to assess whether MRI findings can replace logopedic examination for diagnostic purposes. MATERIAL AND METHODS: 56 subjects were examined by the following methods: - Logopedic examination according to Kittel (1998) - MR images of the tongue resting position (T1-weighted) and deglutition process (2D-FIESTA technique) - MRI analysis according to Fujiki et al. (2000) RESULTS: We observed marked differences between the logopedic and MRI findings, yet there were no significant correlations between the logopedic outcome and distances measured via MRI in tongue resting position and swallowing patterns. CONCLUSION: We noted little concordance between logopedic findings according to Kittel and MRI analysis according to Fujiki et al. Which of these findings correctly reflects the actual clinical situation remains unclear.