Effects of occlusal splints on shoulder strength and activation

Abstract

Introduction: The use of oral appliances to enhance sports performance has been advocated by some authors, however, studies addressing the effectiveness of these strategies are inconclusive. Methods: Here we investigate the effects of dental occlusions on shoulder strength. Fourteen healthy male subjects (age ¼ 21.67 ± 0.86 years) without temporomandibular joint (TMJ) disorder participated in this study. Isokinetic strength was evaluated in shoulder abduction/adduction and arm external/internal rotation tests. Three randomised conditions were assessed: (1) occlusal splint (OS), which repositioned the TMJ in centric relation; (2) placebo splint (PS); and (3) no-splint (N). The strength tests were performed at a speed of 60 /sec in concentric mode. Muscle activity was measured by surface electromyography (EMG) in the main muscles engaged in the movements. Results: Significant differences in peak torque between OS and both of the other experimental conditions were found in some of the analyzed variables. Moreover, there was significantly higher muscular EMG activation in the OS condition when compared to the other conditions for some of the tested muscles. These data suggest that splints may have a positive ergogenic effect on shoulder muscular strength in healthy male subjects. Conclusion: OS may provide an advantage for healthy subjects engaged in sports whereby shoulder and arm strength are important for performance. KEY MESSAGES Occlusal splints in centric relation position have an ergogenic effect, by increasing strength and muscle activation on shoulder in healthy subjects. These results could have implications for sports or other physical activities were arm and shoulder strength are important.

Occlusal Splints and Exercise Performance: A Systematic Review of Current Evidence

“…Athletic performance is the result of the joint interaction of a multitude of factors [ 1 , 2 ]. In-field and laboratory research, as well as clinical experience, led to the observation of the frequent symptomatic connections between the constitutive elements of the postural chain, and on how alterations of these connections may influence athletic performance through postural adaptations [ 3 , 4 , 5 , 6 , 7 ]. Thus, different interventions have been performed in order to analyze, and better understand the impact of postural chain connection alterations, on human performance [ 8 , 9 ].…”

“…In this regard, the application of different mandibular orthopedic repositioning appliance (MORA) devices, as the occlusal splints (OS), in order to enhance or re-establish athletes’ performance level, represented object of increasing interest in the scientific community. The principle behind the application of MORA, and in particular of the OS, is based on the observations by which dental occlusion (i.e., dynamic relationship between the maxillary and mandibular teeth when they approach each other) may affect physical performance by improvements of the temporomandibular joint (TMJ) alignment in the vertical dimension of occlusion, which under remote voluntary contraction (RVC) of the temporomandibular system (TMS) muscles (jaw clenching), may contribute to the phenomenon called concurrent activation potentiation (CAP) [ 4 , 18 , 19 ]. The neuromuscular effects of jaw repositioning and contraction of the TMS muscles may translate to improved neuromuscular responses in active exercise movers and consequently contribute to strengthen movements [ 4 , 15 ].…”

“…When a part of the motor cortex is active, connections to the other areas of the motor cortex are also affected [ 19 ]. Moreover, improvements in neuromuscular connections with jaw repositioning have been observed in muscular activation and proprioceptive feedbacks from the TMJ, projected via afferent fibers to accessory nerve nuclei, and influencing the extent of the neuromuscular response [ 4 , 15 , 18 ]. The current understanding is that the TMS and the whole-body neuromuscular system are connected via the central nervous system (CNS), and that changes in dental occlusion may affect both, static, dynamic muscle balance, and body posture, through output signals transmitted in the trigeminal nerve, which is associated to the mandibular proprioception [ 20 , 21 ].…”

Effect of a sports mouthguard on the functional range of motion of the spine and the upper body posture in taekwondo

“…Beside the protective function, bite splints are intended to generate a more harmonious posture and thus positively promote sporting performance. This interdisciplinary approach to compensate for temporomandibular dysfunctions (TMD), to alleviate acute pain phases and avoid unphysiological tooth contact on the one hand, and to positively change body posture on the other hand, has been analyzed in different studies [6][7][8][9][10][11][12][13][14][15][16][17]. As early as 1926 Schwarz [18] discovered that the lower jaw adapts to the head movements.…”

Systematic changes of the static upper body posture with a symmetric occlusion condition

“…To understand the link between specific occlusion condition and body posture better, investigations were initiated on immediate effects of different occlusion conditions of the body posture [4,[9][10][11][16][17][18][19][20][21][22][23][24][25][26][27]. In a pilot study, März et al [10] could demonstrate that the fleche lombaire and the Kyphotic angle changed slightly with a symmetrical occlusal interference with cotton rolls compared to habitual bite position.…”