# Use of Tens in the Diagnosis of Functional Mandibular Lateral Deviation
###### Abstract  
Introduction: The traditional diagnosis of functional lateral deviation is based on a clinical evaluation and dental casts, supported by an instrumental analysis through X-rays; however, these diagnostic techniques do not provide any information about the neuromuscular system. Several years ago, some authors stressed the importance of the mandibular rest position and its reproducibility as a diagnostic reference, and this became possible with the development of the Myomonitor, TENS. Aim: The aim of this study was to compare mandible position before and after the use of ultra-low-frequency transcutaneous electric nervous stimulation (ULFTENS) in children with diagnosed functional mandibular lateral deviation. Methods: This study was performed on 60 children, aged between 8 and 13 years, with a mean age of 10.1 years (SD 0.81), and with functional mandibular lateral deviation diagnosed clinically, who were referred to the dental clinic for pediatric dental care. Diagnostic neuromuscular registrations were made for all children, and their casts were mounted on a Galeti articulator at the myocentric position. These casts were then compared to those provided by a wax bite registration in the intercuspidal position. Results: Compared with the existing intercuspidal position, neuromuscular registration showed improvement in 30 (50%) patients, 18 patients (30%) showed no changes, and worsening of the tooth midline discrepancy was assessed in the remaining 12 (20%). The molar relationship did not follow the same trend of the midline because of the three-dimensional changes in the maxilla-mandibular relationship induced by TENS. After TENS, there was a significant correlation between the midline and right side deviation (r > 0.65); there was no correlation between the midline and the left side (r < 0.65). Furthermore, the right molar movement showed no correlation with the contralateral molar (r < 0.65). The posterior areas of the arch moved in a very unpredictable way, resulting in the diagnosis and prognosis of mandibular lateral deviation as absolutely individual and unpredictable. Conclusions: This study suggests that TENS-recorded occlusion is an interesting diagnostic approach in orthodontics since it allows for visualizing the trends of the neuromuscular system. TENS; lateral deviation; myocentric position; growing patients +
Footnote †: journal: Medical  
neuromuscular asymmetry because of birth trauma associated with muscular torticollis and/or ocular defects [3; 4; 5; 6; 7]. The traditional diagnosis of functional lateral deviation is based on a clinical evaluation and dental casts, supported by an instrumental analysis through X-rays in the postero-anterior projection; however, these diagnostic techniques do not provide any information about the neuromuscular system [8; 9]. Among the parameters used for orthodontic diagnostic evaluation, the vertical dimension of occlusion, the antero-posterior and latero-lateral reciprocal relationship of the dental arches are of fundamental clinical importance. Variations in the spatial relationship between the upper and lower arches, compared to ideal standards, are relevant factors in the design of the orthodontic treatment plan [10]  
Typically, orthodontic treatment of a functional lateral deviation consists of therapy with different devices that align the jaw. Often, orthodontic treatment, despite possible immediate aesthetic success, determines a constrained occlusal position that could determine long-term stability problems; occlusion does not require neuromuscular adaptation, but rather, orthodontic treatment must adapt to the neuromuscular system and not vice versa [11; 12]. One of the possible hypotheses regarding the instability of orthodontic results could be that the neuromuscular balance was not taken into account during the diagnosis and treatment of laterodeviations. Thus, orthodontic treatment could achieve an aesthetic result at the expense of neuromuscular balance. This could lead to instability of the result in the medium and long term.