3D Digital Dentistry
Dr. Gamboa and the Hidden Tooth
These days, oral implant clinicians have access to different image modalities. However when it comes to which type of radiograph to use, the computated tomograph, CT, is the superior modality. Ralph Gamboa, D.D.S., a Reno Nevada periodontist and experienced user of SimPlant, can testify to the advantages of CT over panographic or periapical radiographs. Dr. Gamboa is currently enrolled in the Misch Institute's bone augmentation course.
A fully edentulous patient presented to his office and based on clinical examination and panographic radiographs, Dr. Gamboa decided this patient would be an ideal candidate for bilateral sinus graft and ridge augmentation. After consultation with Dr. Carl Misch, it was decided that prior to the ridge augmentation, a bone harvest surgery from the patient's hip would be necessary. Patient and clinician both looked forward to a successful surgery with lasting results. Protocol at the Misch Institute requires that treatment planning for each implant case must be based on data derived from a CT scan converted into a SimPlant study.
SimPlant study clearly showing the “Hidden Tooth”.
When Dr. Gamboa combined the technology of CT images and SimPlant software, an otherwise unobservable maxillary tooth was discovered, oriented at a ninety-degree angle from its normal position. The three dimensional qualities which characterize a SimPlant study, consisting of panoramic, transverse-axial, and cross-sectional images, clearly showed that a revised treatment plan was needed for this case. Had Dr. Gamboa proceeded with the original treatment plan, a very unwelcome surprise would have complicated the augmentation procedure. It may have led to an extremely invasive bone harvesting procedure that was ineffective for augmenting the ridge. The consequences of treatment plans based on inadequate information can range from annoying to disastrous. The benefits of viewing images in three dimensions, such as location of anatomic boundaries, image enhancements, and accurate measurements, greatly reduce the amount of guesswork and unpleasant surprises.
Sonick, et al, Int J Max Implants, 1994; (9).
Sonick, et al. (1994) reported on a study conducted at Yale University. Diagnostic radiologist Dr. James Abrahams compared distortion and magnification factors inherent in radiographs and CT scans. The study exposed cadaver mandibles to different radiation techniques and compared them to actual measurements by dissection. A significant difference in levels of distortion and magnification was found. According to the Sonick article, CT has 13 times less distortion than a panoramic radiograph and 8 times less distortion than a periapical radiograph. In addition, the panoramic image is characterized by variable magnification, both vertically and horizontally. It is even possible for this type of radiograph to contain both areas of magnification as well as minification.