Dr. Horowitz is a graduate of the Medical University of South Carolina. In 1992, he founded the Carolina Center for Advanced Dentistry, a multi-disciplinary group practice in the Conway/Myrtle Beach, SC, area. He is founder and clinical director of Advanced Sleep and TMJ Centers, a past member of the Academy of General Dentistry’s Dental Education Council, a mentor at the Kois Center, and a co-founder, lecturer, and key opinion leader for Dentists IN the Know.
As a perpetual student and clinical instructor in the disciplines of dental function, I am too often reminded that most dentists are never taught to view the structure and health of the temporomandibular joint (TMJ) as a primary source of malocclusion, muscle dysfunction, and restorative failure. CBCT is perhaps the single most important technology to make comprehensive screening for TMJ disorders available to virtually all dentists.
Case in Point
A 76-year-old woman presented for initial consultation with a primary complaint of right-sided TMJ popping and associated right temporal and facial headaches, symptoms that had progressed significantly in recent weeks. Despite mentioning these symptoms to other dentists, she had not been offered a diagnosis or solution to help resolve them other than a hard fl at plane splint, which was of little help.
A full field of view (15×16) scan in standard mode was captured with a single pass on a PreXion3D Explorer PRO CBCT and the data were analyzed using the PreXion3D Viewer software. Gross exam revealed a Class II skeletal pattern (Figure 1) and multiple restored lower posterior teeth, although no recent dental work had been done. There was a right posterior occlusal prematurity. The right joint was tender to physical loading and the mandible deviated to the right on opening until a mid to late opening “pop” was heard and felt. Physical symptoms were then correlated to the CBCT findings.
Sagittal, axial, and coronal views were all corrected for angulation by adjusting the colored line crosshairs (Figure 2). Views of the condyle and articular fossae relationship were observed at the lateral and medial poles for morphology, positioning, and pathology on a CBCT TMJ screening form (Advanced Sleep and TMJ Centers). The following observations were made:
Right: Coronal view (Figure 3) shows decreased lateral intracapsular space, significant flattening to the lateral, and evidence of a subchondral cyst. Superior to inferior condylar height shortened 8.5 mm compared to 11.5 mm on the left (Figures 4 & 5). Sagittal view shows significant flattening noted at lateral pole (Figure 6) and posterior condylar positioning at the medial pole with increased intracapsular space anteriorly (Figure 7).
Left: Coronal view (Figure 5) shows relatively normal morphology and cortical plate integrity. Intracapsular space more regular lateral to medial than that of right (Figure 4). Sagittal view shows a more notably distalized condyle at the medial pole (Figure 8) with increased anterior intracapsular space. The lateral pole (Figure 9) shows significant remodeling and osteophytic change.
By correlating the CBCT data with the clinical information, it was understood that anterior repositioning of the mandible with posterior support could be of benefit for the clinical symptoms, as well as the physiologic function of the joint complex by creating a more favorable condyle/disk relationship. A lower orthotic resin appliance was fabricated in the simulated bite and delivered to the patient for full-time wear (Figures 10 & 11). She has been free of pain and loud joint sounds; after 3 months occlusion will be restored posteriorly to support the new condyle/disk/fossae relationship.
The Power of 3D Imaging
Without having 3D CBCT images, I would not have felt comfortable repositioning this patient’s mandible and potentially compressing the articular eminence and condyle. With this information, sound treatment planning with a more predictable result can be offered, creating patient satisfaction along with a better bottom line.
