Treatment Effects of the Mandibular Anterior Repositioning Appliance (MARA) and Conventional Orthodontic Mechanics on Temporomandibular Joint Morphology: A Comparison Using Cone Beam Computed Tomography

Introduction: An ongoing debate exists in orthodontics about the amount of condylefossa remodeling and growth seen in Class II patients using functional appliance therapy. Some clinicians and researchers have found that that the use of functional appliances increases the amount of condylar growth and subsequent Class II skeletal correction; others believe that the mandible has a preset amount of growth and that conventional orthodontics will result in a similar amount of condylar growth to functional appliance therapy. Purpose: The aim of this study was to compare condylar remodeling in functional appliance treatment using the mandibular anterior repositioning appliance (MARA) to conventional fixed orthodontic therapy by measuring changes using Cone Beam Computed Tomography (CBCT). Methods: This retrospective study was an analysis of cone beam computed tomography images taken on 65 subjects with Class II division 1 malocclusions at the beginning and end of their comprehensive orthodontic treatment. Thirty-three subjects (13 females, 20 males; average age 11.93 years) were treated with the MARA plus edgewise mechanics, and a sample of thirtyone subjects (18 females, 13 males; average age 12.37 years) were treated with full fixed conventional orthodontic appliances and class II intermaxillary elastics. The CBCT scans were evaluated using Dolphin3D©. Temporomandibular joint (TMJ) measurements were recorded in the sagittal, axial, and coronal axes, and lateral cephalograms were extracted to compare groups and evaluate treatment differences. A total of 98 variables were measured. Results: Slightly more mandibular advancement was seen in the MARA group versus the conventional group. In looking at the TMJ dimensions, the joint spaces were relatively constant throughout treatment, but more resorption of the condylar head was observed in the MARA group versus conventional treatment. The condylar head angle decreased for both treatment groups, showing a forward remodeling. Lengthening of the condylar process was statistically greater in the MARA group than the conventional Edgewise treatment group, although both increased on average. The slope of the posterior border of the articular eminence became more acute in the MARA group and more obtuse in the conventional Edgewise group. Overall, there was a relative increase and forward advancement of the temporomandibular apparatus in both treatment groups. Conclusions: Both treatment groups were successful in correcting the Class II malocclusion skeletally and dentally. However, the MARA group had slightly more mandibular advancement and condylar growth than the conventional treatment group. In both groups, the TMJ structures increased and came downward and forward partly due to treatment and, to some extent, growth in the adolescent subjects

Robotic conveyance of artillery projectiles for remote ammunition resupply operations

The U.S. Army`s Project Manager, Advanced Field Artillery System/Future Armored Resupply Vehicle has given Oak Ridge National Laboratory the task of developing a robotic conveyance system which will provide automated artillery ammunition transfer. This technology is currently being developed and will be demonstrated in the summer of 1995. This paper describes the development of an ammunition transfer arm to date. The arm consists of three sections and 6 D.F. which will allow the Future Armored Resupply Vehicle to dock and mate with the Advanced Field Artillery System on terrain varying from {+-}10{degrees} in pitch, yaw, and roll and will allow for alignment of the fuel and propellant transfer ports. This arm will deliver the ammunition to the AFAS, where it will be received by an automatic handling and storage system inside the AFAS

A new species of <i>Pagurus</i> (Crustacea: Decapoda: Paguridae), new records and a redescription of hermit crabs from the Mexican Pacific

New records are provided for three species of little-known pagurids. All the material reported was collected by the R/V “El Puma” in the central Gulf of California during the GUAYTEC II cruise. New material is reported for Iridopagurus haigae García-Gómez, 1983, Enallopagurus spinicarpus (Glassell, 1937), and Solenopagurus diomedeae (Faxon, 1893), and these two latter species are redescribed. A new species of hermit crab of the genus Pagurus Fabricius, 1775, is described and illustrated in detail. Among the eastern Pacific species of Pagurus, this new species resembles Pagurus meloi Lemaitre and Cruz Castaño, 2004, P. imarpe Haig, 1974 and P. delsolari Haig, 1974, but differs from these three species in the armature and setation of the chelipeds and second and third pereopods, the shape and armature of the telson, and the number of rows of scales on pereopodal rasp and the presence of a preungual process

The laboratory telerobotic manipulator program

New opportunities for the application of telerobotic systems to enhance human intelligence and dexterity in the hazardous environment of space are presented by the NASA Space Station Program. Because of the need for significant increases in extravehicular activity and the potential increase in hazards associated with space programs, emphasis is being heightened on telerobotic systems research and development. The Laboratory Telerobotic Manipulator (LTM) program is performed to develop and demonstrate ground-based telerobotic manipulator system hardware for research and demonstrations aimed at future NASA applications. The LTM incorporates traction drives, modularity, redundant kinematics, and state-of-the-art hierarchical control techniques to form a basis for merging the diverse technological domains of robust, high-dexterity teleoperations and autonomous robotic operation into common hardware to further NASA's research

Telerobotic manipulator developments for ground-based space research

New opportunities for the application of telerobotic systems to enhance human intelligence and dexterity in the hazardous environment of space are presented by the National Aeronautics and Space Administration (NASA) Space Station Program. Because of the need for significant increases in extravehicular activity and the potential increase in hazards associated with space programs, emphasis is being heightened on telerobotic systems research and development. The Automation Technology Branch at NASA Langley Research Center currently is sponsoring the Laboratory Telerobotic Manipulator (LTM) program at Oak Ridge National Laboratory to develop and demonstrate ground-based telerobotic manipulator system hardware for research and demonstrations aimed at future NASA applications. The LTM incorporates traction drives, modularity, redundant kinematics, and state-of-the-art hierarchical control techniques to form a basis for merging the diverse technological domains of robust, high-dexterity teleoperations and autonomous robotic operation into common hardware to further NASA's research

Use of the Modified Light Duty Utility Arm to Perform Nuclear Waste Cleanup of Underground Waste Storage Tanks at Oak Ridge National Laboratory

The Modified Light Duty Utility Arm (MLDUA) is a selectable seven or eight degree-of-freedom robot arm with a 16.5 ft (5.03 m) reach and a payload capacity of 200 lb. (90.72 kg). The utility arm is controlled in either joystick-based telerobotic mode or auto sequence robotics mode. The MLDUA deployment system deploys the utility arm vertically into underground radioactive waste storage tanks located at Oak Ridge National Laboratory. These tanks are constructed of gunite material and consist of two 25 ft (7.62 m) diameter tanks in the North Tank Farm and six 50 ft (15.24 m) diameter tanks in the South Tank Farm. After deployment inside a tank, the utility arm reaches and grasps the confined sluicing end effecter (CSEE) which is attached to the hose management arm (HMA). The utility arm positions the CSEE within the tank to allow the HMA to sluice the tank's liquid and solid waste from the tank. The MLDUA is used to deploy the characterization end effecter (CEE) and gunite scarifying end effecter (GSEE) into the tank. The CEE is used to survey the tank wall's radiation levels and the physical condition of the walls. The GSEE is used to scarify the tank walls with high-pressure water to remove the wall scale buildup and a thin layer of gunite which reduces the radioactive contamination that is embedded into the gunite walls. The MLDUA is also used to support waste sampling and wall core-sampling operations. Other tools that have been developed for use by the MLDUA include a pipe-plugging end effecter, pipe-cutting end effecter, and pipe-cleaning end effecter. Washington University developed advance robotics path control algorithms for use in the tanks. The MLDUA was first deployed in June 1997 and has operated continuously since then. Operational experience in the first four tanks remediated is presented in this paper

Letter to H.B. Stenzel from Steve A. Glassell on 1934-08-20

Jackson School of Geoscience

A new stomatopod crustacean from the west coast of Mexico

Volume: 92Start Page: 53End Page: 5

Four new species of North American crabs of the genus Petrolisthes

Volume: 35Start Page: 223End Page: 22