Cortical Cloaking

The primary mode of radiographic visualization within the dental environment utilizes the bitewing, periapical, or orthopantomographic image, viewed either digitally, or by film equivalent. Many of us where trained, licensed, and have been in dental practice prior to the now present incorporation of CBCT technology.

Over the past number of years the integration of CBCT technology has enormously benefited dental implantology. All the while this same CBCT technology can vastly improve our ability to view, and therefore diagnose an endodontic case.

Seltzer and Bender in the J.O.E. November 2003 described the interpretative challenge of visualizing pathology unless it has progressed and eroded into the cortical bone. In other words the density of the cortical bone impedes our visualization of pathology contained within the less dense medullary or cancellous osseous tissue. I have taken the liberty to label this anatomic reality as “cortical cloaking”. Any sized lesions or dentinal defects contained within the cancellous bone are generally “cloaked”, therefore not visualized well with a routine periapical radiograph, unless the defect has removed a significant portion of the adjacent cortical architecture. “Cloaked” visualization also presents with root resorption patterns amongst other dental situations, such as significant fractures, and secondary anatomy.

CBCT slices yield digital visual information of cancellous osseous tissue allowing us in dentistry to remove this “cortical cloaking” and vastly improve our ability to render, for our patients benefit, the nature and extent of their actual condition.

This case presented in my office with considerable discomfort stemming from maxillary quadrant. Percussion sensitivity and radiographic information determined the consideration for endodontic intervention #2 and #3. We went ahead and suggested a CBCT scan to visualize further information. Surprisingly, though not apparent on the periapical radiograph, the MB buccal aspect of #3 presented with a 4x5mm. resorption defect, demarcated by the green arrow in this anatomic slice.

This coronal slice gives further visual evidence as to the extent of the MB root resorption pattern, apical lesion, as well as medullary osseous tissue loss from the furcation of #2 along with maxillary antrum thickening.

Here another case was referred, due to generalized discomfort, with a possible suspicious maxillary osseous lesion between the roots of teeth #1 and #2. The decision was made to acquire a CBCT scan.

The sagittal view also displays the apical lesion along with a view of the cortical osseous density.

This coronal slice gives further visual evidence as to the extent of the MB root resorption pattern, apical lesion, as well as medullary osseous tissue loss from the furcation of #2 along with maxillary antrum thickening.

CASE #3

Fracture patterns can also be visualized in certain cases. Here the foreshortened periapical radiograph was noncontributory, and the decision was made to acquire a low volume CBCT scan of the anterior maxilla.

Every working day we as dental clinicians are asked to diagnosis, and therefore interpret radiographs, trying to determine etiologies of our patient’s symptoms. The density of the cortical bone has often been a “cloaking” tissue preventing clinician’s visualization of pathology contained within the cancellous osseous anatomy. The incorporation of CBCT scanning technology within the dental environment has unveiled the “cortical cloaking” making way for 3-D imaging of the osseous medullary space. Many of us now have access to this technology, and when appropriate we best serve our patient’s needs, visualizing more diagnostic information. Familiarize yourself, and your staff with the low exposure levels of these modern machines, integrating them into an “uncloaked” standard of care within our profession.

Dr. Jeffrey Krupp, a Board-Certified Diplomate of the American Association of Endodontics, has been in full-time endodontic practice for more than 35 years in San Jose, California. He earned a DDS degree at UCLA dental school and received his postgraduate endodontic certificate and MS at Marquette University. His passionate interest in education and sharing knowledge is the energy behind “Success In Endodontics 2.0” an endodontic interactive self-study CE program created by Dr. Krupp at www.successinendodontics.com.