Disk displacement, eccentric condylar position, osteoarthrosis – misnomers for variations of normality? Results and interpretations from an MRI study in two age cohorts

Abstract

BackgroundClinical decision-making and prognostic statements in individuals with manifest or suspected temporomandibular disorders (TMDs) may involve assessment of (a) the position of articular disc relative to the mandibular condyle, (b) the location of the condyle relative to the temporal joint surfaces, and (c) the depth of the glenoid fossa of the temporomandibular joints (TMJs). The aim of this study was twofold: (1) Determination of the prevalence of these variables in two representative population-based birth cohorts. (2) Reinterpretation of the clinical significance of the findings.MethodsFrom existing magnetic resonance imaging (MRI) scans of the TMJs that had been taken in 2005 and 2006 from 72 subjects born between 1930 and 1932 and between 1950 and 1952, respectively, the condylar position at closed jaw was calculated as percentage displacement of the condyle from absolute centricity. By using the criteria introduced by Orsini et al. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 86:489-97, 1998), a textbook-like disc position at closed jaw was distinguished from an anterior location. TMJ morphology of the temporal joint surfaces was assessed at open jaw by measuring the depth of the glenoid fossa, using the method proposed by Muto et al. (J Oral Maxillofac Surg 52:1269-72, 1994).Frequency distributions were recorded for the condylar and disc positions at closed jaw.Student’s t-test with independent samples was used as test of significance to detect differences of condylar positions between the age cohorts (1930 vs. 1950) and the sexes. The significance levels were set at 5%. First, the results from the measurement of the age cohorts were compared without differentiation of sexes, i.e., age cohort 1930–1932 versus age cohort 1950–1952. Subsequently, the age cohorts were compared by sex, i.e., men in cohort 1930–1932 versus men in cohort 1950–1952, and women in cohort 1930–1932 women men in cohort 1950–1952.ResultsIn both cohorts, condylar position was characterized by great variability. About 50% of the condyles were located centrically, while the other half was either in an anterior or in a posterior position. In both female cohorts, a posterior position predominated, whereas a centric position prevailed among men. Around 75% of the discs were positioned textbook-like, while the remaining forth was located anteriorly. Age had no statistically significant influence on condylar or on disc position. Conversely, comparison between the age groups revealed a statistically significant decrease of the depth of the glenoid fossa in both older cohorts. This age-dependent changes may be interpreted as flattening of the temporal joint surfaces.ConclusionsWe call for a re-interpretation of imaging findings because they may insinuate pathology which usually is not present. Instead, anterior or posterior positions of the mandibular condyle as well as an anterior location of the articular disc should be construed as a variation of normalcy. Likewise, flattening of articular surfaces of the TMJs may be considered ...

Temporomandibular disorders: a review of current concepts in aetiology, diagnosis and management

“…The estimated prevalence of TMD degenerative joint disease (DJD) diagnosis, also associated with TMJ noises, is 17%. Of note, TMJ DD, the presumed cause of TMJ ‘clicking’, has been argued to be a normal anatomical variant of TMJ disc position, given its high prevalence in asymptomatic populations. A meta‐analysis of non‐patient studies estimated the need for TMD treatment in adults is 16%, with higher values for studies of older individuals (≥46 years) and those where need was clinically assessed (vs. perceived by participants).…”

Pain Management Associated with Posttraumatic Unilateral Temporomandibular Joint Anterior Disc Displacement: A Case Report and Literature Review

“…This examination process in children with suspected TMD, and particularly ADDR, should involve the careful assessment of three main anatomical joint structures: (a) the position of articular disc relative to the mandibular condyle; (b) the location of the condyle relative to the temporal joint surfaces; and (c) the depth of the glenoid fossa. It is also important to collect information about previous direct or indirect trauma (sometimes also called “macrotrauma”) in the orofacial area, particularly chin or TMJ injuries [ 19 , 20 ]. Additionally, it is imperative an exhaustive clinical assessment: mandibular range of motion evaluation, temporomandibular joint palpation including ligaments and capsule structures, masticatory musculature (temporalis and masseter) pain under pressure, load testing, sound detection (clicking, crepitus, and hard-tissue grating); this process should be complemented with diverse auxiliary imaging (e.g., panoramic X-ray, panoramic TMJ images, cone beam computed tomography, and magnetic resonance imaging) [ 9 ].…”

Undergraduate Students’ Knowledge on Temporomandibular Disorders in Croatia

“…Cooper and Kleinberg 7 noted that TMDs decreased with age if the patient population was observed without diff erentiating particular diagnoses. Namely, the general term TMD is used very often, which leads to obscuring the suppositions of the Research Diagnostic Criteria for TMD (Axis I) usage, which enables classifi cation of individual myogenic and/or arthrogenic diagnoses [41][42][43][44] . Th erefore, when observing particular diagnoses, there is diff erentiation between disc displacement diagnosis where the mean age is closer to 30, whereas the age peak for patients with osteoarthritis of TMJ moves to the mean age between 50 and 60 5 .…”