An electronic, computerized pantographic reproducibility index for diagnosing temporomandibular joint dysfunction

One of the signs and symptoms of TMJ dysfunction is incoordinated mandibular movements. The PRI quantitates the incoordinated movements and gives a muscle dysfunction score and the relative severity of TMJ dysfunction. An electronic, computerized pantograph (Pantronic) has been developed that can be used in place of the mechanical pantograph. This study was undertaken to determine if the Pantronic can be programmed to produce PRI scores that are comparable to the M-pantograph PRI scores. Several programs were written for the computer until the Pantronic PRI was comparable to the M-pantograph PRI. The Pantronic PRI was within zero to 5 points of the M-pantograph PRI in all of the 25 patients studied. Because of this close comparison, studies used to validate the M-pantograph PRI also validate the Pantronic PRI. There was, however, a statistically significant difference (.05 level) between the two PRI scores. In spite of this difference the categories of TMJ dysfunction remained the same. The Pantronic PRI can be determined clinically in 20 to 30 minutes. It can be used to determine the presence and, more important, the absence of TMJ dysfunction; the success of occlusal splint therapy, occlusal adjustment, and restorative treatment; the changes in dysfunction over time; the success of other treatment modalities; and the level of dysfunction in TMJ dysfunction research.