Methods: Patients who were scheduled for dental implants placement in the posterior jaws were examined. The distance from the bottom of the osteotom to nearest cortical bone (residual distance RD) was measured. Panoramic radiograph with the pilot drill inserted into the osteotom was taken. Than, using computer program (Planmeca Dimaxis®), the calibrated RD was measured from the end of the drill to the nearest cortical bone (resXR). The same RD was measured using the ultrasound (resUS). Student paired t-test and Pearson's correlation coefficient test were made for comparison between the measuring techniques.
Results: 26 implants were installed and examined in 20 patients.This include14 implants in the posterior mandible and 12 implants in the posterior maxilla. The mean resXR was 4.73mm (±1.84SD), while mean resUS was 5.41mm (±2.2SD). Paired t-test analysis showed no significant difference between the measurements (different 0.054mm, p=0.731). Pearson's correlation coefficient revealed significant positive correlation between these two measurements (r= 0.877, P=0.00).
When data was analyzed for implants in the mandible only (n=14), the mean resXR was 5.55mm (±2.1SD), while the mean resUS was 5.67mm (±2.2SD). Paired t-test analysis showed minor and not significant difference between the easurements (different 0.122mm, p=0.55). Again, significant and strong correlation was found between resXR and resUS (r= 0.942, p=0.00).
Conclusion: The results of this study suggest that the ultrasound device was capable of measuring the distance from the bottom of the osteotom to the mandibular canal or the maxillary sinus. The linear correlation between the JetGuidTM measurements and radiographic measurements imply that this device may give reliable information which might reduce the need for intra operative radiography. Further studies are still needed.