Effects of intervertebral disc disorders of low back on the mandibular kinematic: kinesiographic study

BACKGROUND: Intervertebral disc disorders are one of the most common causes of low back pain. Neuromuscular dysfunction frequently is present in patients with lumbar disc herniation. When considering joint dysfunction, it is important to remember that the spine functions as a unit. Dysfunction on one level can trigger compensatory changes in other spinal levels or in other areas of the musculoskeleton. Findings demonstrated the relationship between stomatognathic and postural systems justifying the hypothesis that muscular-skeletal impairment in one system could affect the other one. However, evidence that a lumbar intervertebral disc herniation could influence the mandibular kinematics is still lacking. Aim of this study was to analyse the effects that intervertebral disc herniation of low back could have on the mandibular kinematics. FINDINGS: Kinesiographic evaluations of the mandibular dynamics of 23 adult patients suffering L4/L5 and L5/S1 lumbosacral disc hernation were compared with a non pathological control group. A statistically significant difference of maximal mouth opening (p < .05) and of maximal mouth opening velocity (p < .03) was found comparing the study patients with the control subjects. CONCLUSION: Lumbosacral disc herniation appears to be associated with changes in the activity of mandibular kinematics both in rate and quality of movement. The study suggests the existence of connections between masticatory system and lumbar disk herniation.