Rw. Katzberg et al., ORTHODONTICS AND TEMPOROMANDIBULAR-JOINT INTERNAL DERANGEMENT, American journal of orthodontics and dentofacial orthopedics, 109(5), 1996, pp. 515-520
The purpose of this investigation is to compare the prevalence of inte
rnal derangement of the temporomandibular joints (TMJ) in asymptomatic
volunteers versus symptomatic subjects using magnetic resonance imagi
ng (MRI), with a detailed comparison to clinical signs and symptoms an
d with attention to a prior history of orthodontic treatment. Bilatera
l MRI scans were obtained of the TMJs in 76 asymptomatic volunteers an
d 102 symptomatic patients. A comparison was made to the clinical sign
s and symptoms, a history of orthodontic treatment, and to the MR find
ings. The MRI scans were reviewed using established criteria for disk
displacement and the reviewers were blinded as to the clinical informa
tion. Our results show a prevalence of disk displacement in 25 of 76 (
33%) volunteers and 79 of 102 (77%) patients with a statistically sign
ificant difference (p < 0.001). No statistical link was noted between
a history of prior orthodontic treatment and internal derangement of t
he TMJ.