March 02, 2021
The temporomandibular joint (TMJ) is the joint that connects the lower jaw to the skull. This joint is unique for it allows the lower jaw to move in various directions that helps in normal functions of speech and chewing. The part of the TMJ that connects the jaw to the skull is called the condyle. The condyle is what moves about in the joint cavity and allows the movement of TMJ. The fluidic action of the TMJ is because of a liquid called the synovial fluid. The condyle moves smoothly because of the synovial fluid.
The actions of the condyle in various disorders of the TMJ should be known. In order to study the movements of the TMJ, various instruments and diagnostic aids were manufactured and developed in the past. These aids studied the TMJ at various axis and angles during the various motions of the lower jaw. They help in diagnosing problems related to improper bite (malocclusion), prosthetic rehabilitation (implants, dentures, bridges, etc) and skeletal discrepancies.
Articulators are such devices that help in replicating the condyle and its actions. Various advancements in articulators help in fabricating prosthesis based on condylar movements in all directions. There are also tracing methods which help in studying the extent to which a person can open or close the mouth, move it side to side and identify its functional rest position. These traces can also help in knowing the efficiency of condyles and ultimately the TMJ.
The major problem with articulators was that they were not too versatile and complex ones were time-consuming. Layering the motions of condyles in different directions produced not so accurate results geometrically.
Condylography is a diagnostic aid by Prof. Rudolf Slavicek. Condylography is a method to trace and record the motions of the condyles. It utilizes a complex articulator that is attached at various areas on the face. The patient is asked to make certain movements that are monitored. The aim is to replicate the natural jaw movements with this device. The results can be transferred to a digital device or onto am articulator on which the needed prosthesis can be fabricated.
Condylography can also be a powerful tool in diagnosing neuromuscular problems related to the face. These can be detected through the tracings made by the condylar movements. Any abnormality in the tracings means that the muscle attachments are dysfunctional.
Condylography utilizes hinges and axis. These can be imagined in vertical, horizontal and sagittal planes. Vertical axis of the condyle can help in recognizing if the patient is finding it difficult to move the jaw sideways. Horizontal axis helps in knowing about the extent of mouth opening and closing and returning back to the rest position. Sagittal plane helps in knowing if the lower jaw can slide forward and backward efficiently.
A flaw in the condylar movements in any of these planes can be suggestive of a TMJ disorder. This can have direct effects on speech and chewing. Records obtained from condylography are based on quantity and quality of movements on both left and right side. It also gives us an idea about the changing profile of the face while the condyle is in motion. In all planes, it is important to note from the findings whether the movements are symmetrical or not.
Precision has increased in condylography as it has become computerized. This non-invasive method has helped in correctly identifying both dental and skeletal problems. It helps in rectifying and improving the entire masticatory system (chewing organ). Condylography holds an edge over MRI and CBCT as one can get a better understanding and information of the fossa (where the condyle rests) and disc (helps in condyle movement).
Condylography helps visualize the TMJ in three-dimensions. The hardware involves an upper bow with digital flags and lower bow with double stili to help record the movements. This design helps in faster recording of the mandibular movements and thus quicker diagnosis. Condylography is thus a great tool that has evolved over the years in order to mimic the TMJ and surrounding structures as closely as possible. It eventually helps an individual better retain and adapt to the function and integrity of the oral musculature.