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Purpose. There is a lack of identifying suitable regions in the head that can be used for three-dimensional superimposition techniques. For this reason, with the use of cone-beam computed tomography (CBCT), the ear canals were analyzed to verify changes during a period of three years in the adolescent years.Methods. CBCTs from fifty-six patients (ages: 10 to 20) were used to landmark the anatomy of the ear canals. Each patient was analyzed using two CBCT reconstructions that were taken approximately three years apart. AVIZO® software was used to locate 28 landmarks distributed following the ear canal path and foramina (ovale, spinosum, rotundum, etc.) in the cranial base to obtain spatial relationships. Three-dimensional coordinates were obtained from the landmarks, and the average distance between various landmark pairings was calculated. The repeated measure ANCOVA was used to determine statistical significance.Results. In the main data set, the largest mean distance change was found to be 4.37 mm ± 18.29 mm between the left foramen ovale and the left superior medial ear canal opening. The smallest mean distance change was 0.18 mm ± 3.25 mm between the right inferior lateral ear canal opening and the right inferior medial ear canal opening.Conclusions. During the adolescent years, the ear canal presents dimensional changes. Even though in different areas throughout the canal, the average distances were minor, still, large standard deviations were present; thus, caution should be taken when trying to use this structure for superimposition of CBCTs.

Cold in-place recycling (CIR) is one of the most popular rehabilitation techniques in Iowa. The Iowa Department of Transportation has increased the minimum moisture criterion from 1.5% to 2.0% because many overlays have been successfully applied on the CIR layer with moisture contents above 2.0%. However, a contractor must make daily measurements of the moisture content with a nuclear gauge. It is difficult to achieve 2.0% moisture content during a rainy summer in Iowa. For the curing issue to be addressed systematically, the moisture contents and temperatures of one project of CIR with emulsified asphalt and four projects of CIR with foamed asphalt were monitored. Capacitance moisture and temperature sensors were embedded at the midpoint of the CIR layer to measure moisture contents and pavement temperature. A GeoGauge was used to measure the stiffness. The field data obtained from the embedded moisture sensors and from a weather station were used to develop a moisture prediction model as a function of the initial moisture content, CIR layer temperature, wind speed, and humidity. With the developed moisture prediction model, a contractor can predict optimal timing for placement of the wearing surface without continually measuring moisture contents of the CIR layer with a nuclear gauge. The stiffness of the CIR layer measured with the GeoGauge was found to continue to increase as the curing period increased, despite an increase in moisture content caused by rainfall. The stiffness measured by the GeoGauge steadily increased during the curing period until it reached a value of 30 MN/m. For the optimal timing of an overlay to be determined, the stiffness, rather than the moisture, of the CIR layer should be measured.

Study Design. Retrospective case series.Objective. To document the clinical utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion for patients diagnosed with sacroiliac joint dysfunction (as a direct result of sacroiliac joint disruptions or degenerative sacroiliitis) and determine stimulated electromyography thresholds reflective of favorable implant position.Summary of Background Data. Intraoperative neuromonitoring is a well-accepted adjunct to minimally invasive pedicle screw placement. The utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion using a series of triangular, titanium porous plasma coated implants has not been evaluated.Methods. A medical chart review of consecutive patients treated with minimally invasive surgical sacroiliac joint fusion was undertaken at a single center. Baseline patient demographics and medical history, intraoperative electromyography thresholds, and perioperative adverse events were collected after obtaining IRB approval.Results. 111 implants were placed in 37 patients. Sensitivity of EMG was 80% and specificity was 97%. Intraoperative neuromonitoring potentially avoided neurologic sequelae as a result of improper positioning in 7% of implants.Conclusions. The results of this study suggest that intraoperative neuromonitoring may be a useful adjunct to minimally invasive surgical sacroiliac joint fusion in avoiding nerve injury during implant placement.