Page 78 - Journal of Special Operations Medicine - Fall 2014

and muscle spindles of jaw closing muscles facilitate ad- The wear that occurs on the occlusal surface of the de-
renal nerve activity. 23 vice from bruxing will cause the symptoms (NMs, SDs,
etc.) to recur after varying periods of time. Restoration
In addition, it has been concluded that gradual increase of the original vertical dimension of occlusion (origi-
of intraoral vertical dimension of occlusion may result in nal RNM distance) brings the same clinical result as
decreased masseter muscle sensitivity. This suggests that the original device. This may support the idea that the
peripheral sensory plasticity may occur after changes jaw muscle spindles play the most important role in the
in occlusal vertical dimension. The effects of varying physiological action of this device.
37
the vertical thickness of an occlusal splint on nocturnal
electromyographic activities of the masseter and tempo- Sample size, although small, represents a group of PTSD/
ralis muscles has been measured. It is possible that the mTBI subjects with significant manifestation of comor bid
33
neurons of the trigeminal mesencephalic nucleus play disorder processes (i.e., HAs, NMs, and SDs), which rep-
an important role in the regulation of occlusal vertical resents a legitimate statistical representation to measure
dimension (distance between the jaws) because this response to this therapy as a pilot study for further research.
nucleus receives projection from the jaw-closing muscle Certainly, future research, including true experiment de-
spindles and periodontal mechanoreceptors. 31 signs, should be conducted to define a cause-and-effect
relationship between the RMN and the reduction in sleep
It is also suggested that changes in sympathetic outflow symptomology in PTSD subjects. Additional use of this
to muscle spindles can change rhythmic movement pat- device as an adjunct to cognitive-behavioral therapy and
terns in the masticatory systems of rabbits. This research acute resolution therapy should be explored.
has important implications for the control of motor
functions in states of high sympathetic activity. 30
Conclusions
Masseter length has also been found to determine muscle The use of an RMN is positively correlated with a re-
spindle reflex excitability during jaw closing movements. duction in the experience of PTSD-related sleep symp-
In a study using lateral cephalometric radiographs to toms independent of psychological and pharmaceutical
establish facial heights in patients, it was found that therapies. Scores for nighttime HAs, NMs, and diffi-
shorter facial heights were associated with stronger spin- culties falling and staying asleep significantly lessened
dle reflexes. 36 while the device was in use. Reductions were seen in
both frequency and intensity. Participants commonly re-
The RMN increases the vertical dimension of occlusion ported that improvements in symptoms were immediate
and may change the jaw muscle spindle discharge char- and did not diminish over time.
acteristics. It also may decrease the periodontal mech-
anoreceptor feedback to the trigeminal nucleus The Disclosures
trigeminocervical nucleus is the largest nucleus in the The authors have nothing to disclose.
brain, and its tracts radiate widely to include the thala-
mus and the dorsal prefrontal cortex. Increased output
from the trigeminocervical nucleus may radiate to the Funding and Affiliation
prefrontal cortex, where dreaming occurs. Clinically, This original research was not affiliated with any uni-
the patients report that their NMs are transformed to versity or other institution. Primary financial support
nonthreatening military-themed dreams. was provided by Dr Donald Moeller and secondary
support by research staff. All research materials were
There may also exist a positive feedback loop between generated and constructed by Dr Moeller and staff. No
the bruxism causing pain, which may in turn cause third-party manufacturers were involved in this study.
an increase in output from sympathetic upregulation, The authors have no financial relationships relevant to
which in turn increases the sensitivity of the jaw muscle this article to disclose.
spindles, which then causes the bruxism to increase. The
increased upregulation of the trigimenal nucleus from References
jaw muscle spindle and periodontal output tracts may
cause increase in output to the reticular activating sys- 1. Seal KH, Metzler TJ, Gima KS, et al. Trends and risk fac-
tors for mental health diagnosis among Iraq and Afghani-
tem. This may account for the high number of patients stan veterans using Department of Veterans Affairs health
falling asleep immediately after RNM placement. The care, 2002–2008. Am J Public Health. 2009;99:1651–
shorter facial height patients, many of whom have deep 1658. doi:10.2105/AJPH.2008.150284.
bites (upper incisors well overlapping the mandibular 2. US Department of Veterans Affairs. Symptoms of PTSD.
incisors), seem to have some of the most dramatic re- 3 January 2014. http://www.ptsd.va.gov/public/PTSD-over
sults from use of this device. view/basics/symptoms_of_ptsd.asp.

70 Journal of Special Operations Medicine Volume 14, Edition 3/Fall 2014