Dentaltown January 2017 - 58

More recent work has delved deeply
into force vectors in terms of direction
and magnitude, and it's now recognized
that the forces are related to the direction
of the muscle contraction as well as the
details of the dental contact-including
the observation that the more anterior the
posterior point of dental contact is, the less
force on the joint itself. 8, 9 It has also been
shown that there is no relationship between
"posterior support" and the development of
degenerative changes in the joint.10
Goodfriend, whom Costen references
for the "dental science," needed to support
his clinical fi ndings and assumptions of
mechanism. Both can truly be called pioneers,
but their work was performed and written
about without the use of the scientific
method. The map they created is now
outdated, yet its concepts are still taught.

reading list for many prosthetic graduate
programs to this day, as a result of being
part of the Navy Lit Review.
The work of Travell and Ramjford both
appear in the early 1960s.12-14 Ramjford's
1961 study involved occlusal adjustments
on 32 patients with pre- and post-EMG
studies with no control group. They reported
complete relief of all patients with both
intracapsular and extracapsular disorders by
occlusal adjustments. Conversely to Costen's
work, they suggested that vertical dimension
was not related to symptoms, but that "any
type of occlusal interference was found to
trigger muscle spasms and pain" and the
"the most significant interference was a
discrepancy between centric relation and
centric occlusion." They reported bruxism
in all 32 patients, and related the cause of
bruxism to both psychic and occlusal factors.

Relying on faulty "evidence"

Empirical versus
evidence-based studies

In 1956, Sears published a paper that
further cements the relationship between
occlusion and temporomandibular joint
"disturbances," reporting that the use of
pivot appliances had been so predictably
effective for resolving both dental and
nondental related symptoms that there had
been a hesitation to publish the findings.
Sears quotes McPhee, who writes, "In the
evaluation of this survey, there appears to
be a close relation between malocclusion
and insanity."11 The mechanism provided
includes a report that the condyles are "forced
into strained relations in the fossa" by the
teeth meshing and that anterior contact
creates a Class III lever, and suggests that
the cause of these dental and nondental
symptoms is the occlusion. Sears states,
"The tooth occlusion out of harmony with
jaw relation causes mechanical stress of
the temporomandibular joint." This paper
continues to be referenced and is on the

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JANUARY 2017 // dentaltown.com

The first area of concern is, of course,
the fact that the definition of centric relation
itself has undergone many changes, and the
definition itself remains an area of controversy
in dentistry. "It could be argued that the
progressive modifications in the definition
of CR have done more to eliminate centric
slides than 20 years of grudging acquiescence
of the precepts of gnathology."15
In addition is the predominance of
evidence that has led to the occlusion and
pain "disconnect." Pullinger states, "Belief
in and rejection of a relationship of occlusion and temporomandiublar joint (TMJ)
condyle-fossa position with normal and
abnormal function are still contentious
issues. Clinical opinions can be strong,
but support in most published data (mostly
univariate) is problematic."16
In her study in 2006, Michelotti introduced interferences into patients without
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Table of Contents for the Digital Edition of Dentaltown January 2017
