New Trends and Advances in Oral and Maxillofacial Imaging

Can the lower rate of CT- or MRI-related adverse drug reactions to contrast media due to stricter limitations on patients undergoing contrast-enhanced CT or MRI?

OBJECTIVE

The aim of this study was to examine whether a decreased occurrence rate of adverse drug reactions (ADRs) to contrast media in contrast-enhanced CT and MRI was attributable to appropriate criteria for patients with some diseases. A secondary aim was to elucidate safety profiles for contrast media and factors influencing the occurrence of ADRs.

METHODS

Clinical data of patients who underwent contrast-enhanced CT (5576 cases) or MRI (3357 cases) were retrospectively analyzed to evaluate rates of ADRs to contrast media, symptoms of ADRs, treatments for ADRs, and differences in medical history, blood test results, and other factors between patients with and without ADRs in a dental hospital.

RESULTS

The rate of ADRs to contrast media was 0.54% for CT and 0.09% for MRI. The most frequent ADRs in contrast-enhanced CT or MRI were nausea and vomiting as physiologic reactions. Two serious reactions were seen for CT, but none for MRI. Significant differences between patients with and without ADRs were seen in liver function according to blood tests for CT, and in digestive disorders elicited from medical interviews for MRI.

CONCLUSION

The lower occurrence rate of ADRs to contrast media in dental hospitals could be due to the adoption of appropriate criteria for patients with some diseases undergoing enhanced CT or MRI. Complete suppression of ADRs to contrast media for CT or MRI is unrealistic, so attention is warranted for patients with decreased liver function when performing enhanced CT, and for patients with digestive disorders when performing enhanced MRI.

A spatial association between odontomas and the gubernaculum tracts

OBJECTIVES

The purpose of this study was to identify the spatial relationship and/or association between odontomas and the gubernaculum tract or the dental sac and the characteristic findings for radiographic diagnosis of odontomas.

STUDY DESIGN

The visualizations of the odontomas and the gubernaculum tract were retrospectively analyzed using cone beam computed tomography or multidetector computed tomography.

RESULTS

Most of odontomas were within the gubernaculum tract or dental sac of unerupted permanent teeth on computed tomography. In some odontomas, the gubernaculum tract existed as a well-defined low density tract extending from the top of odontomas on computed tomography.

CONCLUSIONS

A close spatial relationship and/or association between odontomas and the gubernaculum tract or dental sac on computed tomography may be used as one of the criteria for radiographic diagnosis of odontomas. Development of odontomas may be associated with the gubernaculum tract or dental sac of unerupted permanent teeth.

Detection and imaging characteristics of the gubernacular tract in children on cone beam and multidetector computed tomography

PURPOSE

To elucidate the appearance and imaging characteristics of the gubernacular tract (GT) during the growth stage of children. Furthermore, this study evaluated the significance of the appearance of the GT.

STUDY DESIGN

The visualizations of the GT were retrospectively analyzed by using panoramic radiographs and computed tomography (CT) in children.

RESULTS

In patients with normal eruption who had unerupted permanent teeth, except maxillary central supernumerary teeth, the GT was clearly visualized as a well-defined low-density tract on CT but not on panoramic radiographs. In patients with obstructive eruption, including impaction, the GT was deformed and not visible on CT.

CONCLUSIONS

This paper describes the frequency of detection and appearance of the GT in unerupted teeth. Preliminary data suggest that any alteration to the GT may be used to predict abnormal eruption of permanent teeth.

A Diagnosis of Maxillary Sinus Fracture with Cone-Beam CT: Case Report and Literature Review

The purpose of this article is to present the case of maxillofacial trauma patient with maxillary sinus fracture diagnosed with cone-beam computed tomography (CBCT) and to explore the applications of this technique in evaluating the maxillofacial region. A 23-year-old male patient attempted to our clinic who had an injury at midface with complaints of swelling, numbness. The patient was examined before in emergency center but any diagnosis was made about the maxillofacial trauma. The patient re-examined clinically and radiographically. A fracture on the frontal wall of maxillary sinus is determined with the aid of CBCT. The patient consulted with the department of maxillofacial surgery and it is decided that any surgical treatment was not necessary. The emerging technique CBCT would not be the primary choice of imaging maxillofacial trauma. Nevertheless, when advantages considered this imaging procedure could be the modality of choice according to the case.

The effect of 3 T MRI on microleakage of amalgam restorations

OBJECTIVES

To evaluate the effects of 3 T magnetic field on microleakage of amalgam restorations containing three different types of silver (Ag).

METHODS

60 extracted teeth were restored with three different types of amalgam filling materials. Restored teeth were sectioned mesiodistally and divided into experimental and control groups. Experimental groups were exposed to a magnetic field of 3 T for 20 min. All samples were plunged into 2% basic fuchsin solution and examined under a digital microscope by three different observers with regard to microleakage.

RESULTS

Statistical analysis showed significant differences in microleakage between the groups exposed to MRI and controls, whereas differences in microleakage between amalgam types were insignificant.

CONCLUSIONS

The primary risk of MRI systems arises from the effects of its strong magnetic field on objects containing ferromagnetic materials. An MRI of 1.5 T is known to be safe for amalgam restorations. However, our research indicates that MRI is not completely devoid of any effects on amalgam restorations.