3D x-ray helps 81st DS diagnosis, treatment

  • Published
  • By Steve Pivnick
  • 81st Medical Group Public Affairs
KEESLER AIR FORCE BASE, Miss. --  "It's not your daddy's x-ray!"

The 81st Dental Squadron offers state-of-the-art three-dimensional images to aid in diagnosis and treatment of a wide range of dental conditions, including reconstructive surgery.

Maj. (Dr.) Jeffrey Ford, chief of orthodontics and officer-in-charge of radiology for the dental clinic, has two x-ray systems available, each producing 3-D images.

"The cone-beam computed tomography does not provide images as detailed as a medical grade CT, but they are very detailed for what we do in dentistry. One of our systems, the Planmeca, produces panoramic and cephalometric (a side-view radiograph of the head and neck used to gauge the size and spacial relationships of the teeth, jaws and cranium) x-rays.

We are fortunate the equipment, which costs between $80,000 and $100,000, was already in the clinic. The manufacturer was able to produce add-on circuitry allowing it to produce 3-D images. It can also do standard 2-D x-rays without having to swap out sensors."

Ford mentioned several 2-D images can be created from a single CBCT and he is able to increase and decrease the resolution, although higher resolution requires more radiation at the time of the scan.

He noted 3-D images are useful for several dental specialties.
Endodontists, who perform root canals, prefer smaller volumes (amount of image) and high resolution images, while prosthodontists, who replace multiple teeth, want to see the area in question to provide detailed information to the surgeons.

Oral surgeons use the images for several reasons, such as pathology and locating nerves in bones. This allows them to determine how to remove teeth while limiting or avoiding nerve damage.

"It can help reduce the time a patient is under anesthesia and assists the surgeon in producing radiographic guides," said Ford.

Finally, the 3-D images help orthodontists diagnose and treat patients by using all three views: side-to-side, up-and-down front- to-back (sagittal, axial and coronal views also known as multi-planar reconstructions [MPRs]).

"We are able to locate impacted teeth and are provided increased accuracy in diagnosis by scrolling through several views and locating 'landmarks' in the mid-face and lower jaw. "

Ford said he uses the 3-D images to diagnose occlusions (the way a person bites), impacted teeth and to predict surgery outcomes for craniofacial orthopedic patients.
He pointed out the cone beam equipment provides images with 1:1 ratios, meaning there is no image distortion.

To assist in repairing physically-damaged faces, the 3dMD camera creates 3-D pictures that are exact medical-grade representations of a patient, Ford explained.

"Everyone is asymmetric from the left to right side of their face. By combining the cone beam of the skull with a 3-D picture of a physically-damaged face, we can closely predict what the repaired face might look like. This aids the oral and maxillofacial surgeon who can use the computer to plan an entire surgery."

Another useful devise is the 3-D model scanner.

"This is a three-shape model scanner which scans impressions or models. It can send data and reproduce a 3-D image (or a physical model from a 3-D printer) and also can merge with a 3-D picture. However, it can't merge all three (MPRs, 3-D picture of the face and 3-D image of the cast); there's just too much data in the field of view."

Ford continued, "The 3-D images also allow teams of specialists to diagnose, plan treatment and help predict surgical outcomes by collaborating digitally from anywhere on the planet. The data is digital so it is convenient to augment and transport or send. For example, an oral surgeon and orthodontist can coordinate their respective treatments. Both can perform most procedures digitally first to help in the treatment planning process. The orthodontist moves teeth and the surgeon moves the jaw and vice versa. This is a helpful tool and another element in our diagnostic tool box."

He also has the benefit of being able to call upon an expert dental radiologist at Joint Base San Antonio-Lackland, Texas, to review images when necessary.

Ford is no stranger to Mississippi or Keesler. He earned a bachelor of science degree in biology from Mississippi College in Clinton and his doctorate of dental medicine degree from the University of Mississippi School Of Dentistry in Jackson.

His first Air Force assignment was to Keesler where from 2003-2005 he completed the Advanced Education in General Dentistry (AEGD) one-year program and then served on the 81st DS staff. He returned to Keesler in 2010 after completing a two-year residency in orthodontics at then-Wilford Hall Medical Center at Lackland Air Force Base, Texas.
In addition to his role as a staff orthodontist, he is a faculty member of the Bethesda, Md.,-based Uniformed Services University of the Health Sciences teaching the orthodontics module to Keesler's two-year AEGD residents.