One of the major problems in diagnosing and interpreting symptoms at TMD is the difficulty of properly visualizing and understanding what is happening within them. This is due to the fact that this complex structure includes hard tissues (bone) and soft tissues (disc, ligaments, synovial membrane). These structures have different densities and are difficult to visualize with a single imaging technique (exploration). ‘Standard’ panoramic radiography with and without shims allows visualization of dense bone structures.

Modern imaging techniques offer more precision in this case such as MRI which is considered the gold standard in complementary examinations. Axiography is no exception and is also used as a means of dynamic exploration in TMD [1]. These two examinations can be used jointly or separately in the diagnosis of TMD. The aim of this article is to highlight the approach following the non-coincidence of techniques for exploring TMD through a clinical case.

A 14-year-old child consults for musculoskeletal pain in TMJ. His large physique of 1.85 m, thin body with long and thin fingers attracts our attention. The properly conducted anamnesis revealed that the patient has scoliosis. For this purpose, we suspect the presence of a syndrome and we decide to push our clinical examination by orienting the patient to a rheumatologist. The latter following other explorations at its level, confirms us that the patient is suffering from Marfan syndrome. This syndrome is an autosomal dominant genetic disease of connective tissue that affects the heart, skeleton and eyes [2].

The occlusal static and dynamic examination reveals a skeletal class II with the presence of positioning, guidance and mandibular centering (Figure 1).

The dynamic occlusion realized on the patient or on a semi-adaptable articulator showed unproductive protrusive interferences between the 16 and the 17 upper molar and their antagonists the 36 and the 37, and the 26 and 27 and their antagonists 36 and 37. Canine function has straight and a function from group to left . The mouth opening limited to 25 mm deflected to the right side (Figures 2 and 3).

Two additional tests (MRI, axiography) were performed to support the clinical diagnosis and according to the reports we moved to orthopedic treatment in the form of occlusal orthosis, this last well obviously is personalized and realized on semi adaptable articulator (Figures 4-6).

Our clinical diagnosis was an internal disturbance of the meniscus within the TMJ. To our great surprise the additional examinations carried out did not coincide, the examination by MRI T1 and T2 was in favor of a healthy ATM without any abnormality, on the contrary, the axiographic examination showed us a typical trace of an acute irreducible disk displacement.

Axiography is now an integral part of the instrumental and manual functional analysis of the ATM, but the interpretation of the plots must be careful [3-5]. So our plot obtained for the clinical case is similar to those of Dupas. Thanks to the latter’s work carried out in 1992, 1998, 2005 and 2011 respectively and 2015 can be taken as a scientific reference of great importance (Figure 7) [6].

The axiographic record is punctual; indeed, several records taken a few days apart can change the clinical judgment [6]. The patient’s MRI image shows a physiological joint position; comparing it to other MRI images typical of an acute irreducible disk displacement; we find ourselves with the diagnostic criteria of healthy TMD (Figure 8).

Several studies and publications have been done regarding the comparison between MRI imaging and axiography in the diagnosis of internal disturbances of the TMJ. The study carried out in Italy, which received the best poster award and was subsequently published in the international journal of stomatology and occlusion medicine, with an average age of 33 years and whose coincidence between the two complementary examinations was 78.57%; Kappa 13% [7].

Rammelsberg et al. estimates axiography sensitivity of 86% and specificity of 90% and MRI sensitivity between 67%-100% [8]. Piehslinger et al. reported that in 45% of reducible and irreductible disc displacement cases, axiography and MRI gave the same results [9]. Gsellmann et al. in their investigations have deduced that morphological anomalies could be detected by MRI, and axiography determines the dysfunctional dynamics more clearly [10].

Advances in the functional and structural evaluation of TMJ through axiography and MRI enable accurate diagnostic categories to be defined. Although there is no systematic match between functional (possibly axiographic) and structural (possibly MRI) abnormalities [11,12].

Some authors proposed the creation of dynamic MRI with sequences during pseudo-dynamic oral opening and closing movements; unfortunately, they had unreadable images with artifacts and leaks and signal loss during image acquisition [13,14]. The presence of this syndrome may also be a predisposing factor for problems of the mandibular and postural joints, the articular hyperlaxity affects the entire skeleton of the child and the ATMs are no exception with the presence of more or less of the trismus, it is perhaps for this reason that the MRI gave a false negative result of the case [15,16].

Under this situation of diagnostic confusion; we preferred the realization of a complete muscle reconditioning orthosis (occlusal splint) in order to relieve the patient and not to aggravate the initial situation. Unfortunately following the pandemic of covid -19, the checks could not be done as programmed and in addition to that we received no call from the parents of the child reporting an emergency or unbearable pain.

The complementary means used in the diagnosis of TMD such as axiography and MRI are very useful but sometimes they are contradictory, only a properly conducted clinical examination will be able to guide the practitioner in his/her therapeutic approach.