TONGUE MOTOR CONTROL IS IMPAIRED IN PATIENTS WITH TEMPOROMANDIBULAR DISORDER: A PROOF-OF-CONCEPT CONTROL-CASE STUDY

C. Alvarado¹, A. Arminjon¹, C. Damieux‐Verdeaux^1,2, C. Lhotte¹, C. Condemine¹, P. Bouletreau³, S. Mateo^4,5,6

¹Cabinet de Kinésithérapie Saint‐Alexandre, Lyon, France, ²Hospices Civils de Lyon, Hôpital de la Croix Rousse, Lyon, France, ³Hospices Civils de Lyon, Groupement Hospitalier Sud, Chirurgie Maxillo‐Faciale, Pierre‐Bénite, France, ⁴Université Claude Bernard Lyon 1, UFR de Médecine, Lyon, France, ⁵Université de Lyon, Université Lyon 1, Lyon Neuroscience Research Center, Trajectoires Team, CNRS UMR 5292, INSERM U 1028, Lyon, France, ⁶Hospices Civils de Lyon, Hôpital Henry Gabrielle, Plate‐forme Mouvement et Handicap, Lyon, France

Background: Tongue is essential for oro-facial functions which requires both strength and accuracy during its movements. However, tongue motor control is widely reduced to a matter of strength and studies evidenced the relationship between tongue strength deficit and diseases (e.g., swallowing difficulties, temporomandibular disorder - TMD). To date, there is no existing clinical assessment investigating the tongue accuracy.

Purpose: We investigated the accuracy of the tongue placement as a measure of tongue motor control in patients with TMD compared with age‐ and sex‐matched healthy participants.

Methods: This proof‐of‐concept case‐control study was prospective, observational, and part of the TMIQ study (NCT04102306). Each participant pointed against a wood stick while maintaining its tongue as sharp as possible. The examinator drew the contour of the tongue print on the wood stick immediately after pointing before the saliva dry. The stick and contour then scanned for image analyses to compute the area of the tongue print for each participant using ImageJ. Because of the non-parametric nature of the data, the tongue area were compared between groups using paired Wilcoxon's test and result are reported median and interquartile range (IQR) or 95% confidence interval of the medial (95%CI). Statistical significance was set at 5% (p < .05). All statistical analyses were performed using R 4.0.0.

Results: A total of 94 participants were included. Mean age was 38 years (SD=16) and there was 32 women (68%) et 15 men (32%) in each group. Among patients with TMD, all were diagnosed with myalgia, 61% with intra‐articular joint disorder accordingly to the DC/TMD. The median (IQR) tongue print area was significantly higher in the TMD group (area=117 (111) mm2) than in the control group (area=93.5 (76.2) mm2, V = 352, p = .04) and the median [95% CI] difference between TMD and control group was 25.4 [1.3; 51.0] mm². For patients with TMD, there was no significant difference in tongue print area between the categories of the DC/TMD.

Conclusions: The results suggest that TMD impairs the motor control of the tongue. Future studies are welcomed to investigate the psychometric properties related to this measurement in conjonction with other existing and validated tool.

Implications: The sharpest tongue pointing test may constitute a simple and accessible clinical tool to assess the accuracy of tongue placement in TMD patients and can be used in clinical setting to assess tonghe motor control.

Keywords:
Tongue
Motor control
Oro-facial function

Topics:
Musculoskeletal
Disability & rehabilitation

Did this work require ethics approval? Yes

Institution: HOSPICES CIVILS DE LYON

Committee: CPP Sud‐Ouest et Outre‐Mer III

Ethics number: 2018‐A02195‐50