A Proposed Modified Version of the Helkimo Dysfunction Index

Objectives: To evaluate a modified Helkimo Dysfunction Index (mHDI) considering a varaition in the number of painful muscles inspected in patients with Temporomandibular Disorders (TMD).
Methods: 40 consecutive participants (13 men and 27 women, mean age 35.7 +/- 20.96) with TMD were selected from patients who attended the Linares Oral Rehabilitation Institute. Written informed consent was obtained from all participants prior to their enrollment. Axis I protocol of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) was used. A trained examiner performed the procedure. Part 9 of the DC/TMD examination form (Muscle & TMJ Pain with palpation) was used instead the Helkimo muscle exam protocol. Muscle palpation was performed using 1 kg of force. Scores were adapted to such index. According to DC/TMD, 12 muscle fascicles were palpated (temporalis and masseter). Our muscle pain index was defined as: 0=no pain; 1=pain in one to four fascicles; 5=pain in five to twelve fascicles. The other data from the DC/TMD index are used in a similar way with the Helkimo Dysfunction Index. All the data obtained was used with our mHDI. We compared sex and type of diagnosis (Axis I DC/TMD) in order to support our results. Data were analyzed using the Chi-Square test and Rho of Spearman.
Results: Women showed a higher value of the mHDI compared with men (P=0.0247) as well as a greater number of symptomatic muscle fascicles (P=0.03). Patients with headache attributed to TMD and any other TMD diagnoses showed a higher mHDI (P=0.0069). A correlation of r=0.398 between the number of symptomatic fascicles of the masticatory muscles and mHDI was observed (P=0.011). These results demonstrate a moderate relationship between the number of masticatory muscle fascicles and the mHDI.
Conclusions: Our results support the modification of the Helkimo Dysfunction Index based on the Axis I DC/TMD, protocol which requires validation in future.