Feature An Introduction to

Cranial Movement and Orthodontics

This article has been peer reviewed.

By: Gavin A. James, M.D.S., F.D.S. and Dennis Strokon, DDS

n our recent article (International Journal of Orthodontics, of factors contributing to the malocclusion.

I Fall 2003), we presented evidence for the idea of cra-

nial movement and suggested that this was associated
with malocclusion. Such an idea is a radical departure from
The timing of treatment is reassessed in the light of
cranial movement and new work in the field of complexity
and chaos theory. Finally, the implications of resonance
current orthodontic thinking and it is tempting to dismiss and electromagnetic field theory with regard to the force
the concept as irrelevant. However, the framework of ideas systems used in orthodontics is examined.
and methods, which have evolved from the cranial concept, This is an ambitious and controversial undertaking. As
is of fundamental importance to orthodontics and indeed Kuhn1 has pointed out, for a scientific community to
to dentistry. A summary of the principles underlying this change the ideas and methods which it holds in common,
new philosophy appears in the box below. i.e., its paradigm, can be a painful and slow process.
By invitation of the Editor, we propose to develop these However, if the new paradigm offers a better explanation of
ideas in a series of articles. In these articles the cranial, known facts and can also take into account facts which
facial and postural characteristics of each strain are have been ignored or dismissed under the old paradigm,
described together with the malocclusion which results then eventually the community accepts it. Good science
from this. The adaptive and functional behavior, which usu- requires that we be prepared to change our minds if evi-
ally develops, is also discussed with particular emphasis on dence can be shown to call for this. It is our hope that we
temporomandibular joint dysfunction. This is followed by a can provide this evidence.
rationale for treatment, which recognizes the combination Since the series will extend over time, readers might

1. Rhythmic movement of the cranium is a physiologi- cranial strains. Treatment then is aimed at resolving
cal characteristic throughout life. This movement is the cranial factors as far as possible, then correcting
transmitted to the whole body and in particular to the the maxilla and maxillary dentition, then addressing
facial structures. the mandibular arch.
2. Distortions of the cranial structures can occur, espe- 6. Given the reality of cranial movement, the forces
cially during the birth process, but also due to subse- used in orthodontics must be designed to correlate
quent trauma. Once formed, these distortions can be with or enhance the cranial rhythm and not over-
reinforced by soft tissue adaptation. Faulty swallow- whelm it. In practice, this means a much more subtle
ing patterns can perpetuate the distortion. application of force designed to stimulate the innate
3. These distortions or strains, to use the osteopathic capacity of the body to self-adjust and self-correct.
term, fall into two categories: (a) as an exaggeration 7. The existence of cranial movement as a naturally
of physiological movement (Hyperflexion, Hyperex- occurring phenomenon leads to identification of a fun-
tension, Superior Vertical Strain, Inferior Vertical damental inconsistency in current orthodontic think-
Strain) or (b) as disturbances along an anteroposterior ing, namely, that with the application of Newtonian
axis (Torsion, Sidebend, Lateral Strains). mechanics we can expect a predictable linear response
4. Each cranial strain predisposes towards a type of mal- consistent with Newtonian principles. This may not be
occlusion. The importance of the airway, swallowing the case because a complex dynamic system such as
patterns, tongue position and hereditary factors, etc., the human body may not react in this way.
is acknowledged, but an understanding of cranial dis- 8. Current thinking in physics and biology offers a radi-
tortions puts these factors into perspective. cally different approach which incorporates cranial
5. Malocclusion must be seen as an integral part of the concepts and which validates the above statement.
total body picture. Using this approach provides a 9. The anatomical and physiological basis for this new
much more individual and sophisticated diagnosis. approach is presented together with clinical evidence
Treatment planning begins with the identification of of its efficacy.

IJO • VOL. 16 • NO. 1 • SPRING 2005 23

find it useful to consult the DVD made of our presentation In this sense teeth are riders on a system, responding to
at the IAO Convention in Savannah, Georgia, in April of variations throughout the articulations of cranial and
2004.2 The DVD gives an overview of the whole concept facial bones. At the centre of the variable dynamic system
and is available at www.dubking.com. The articles will of bones and sutural movement is the spheno-occipital
allow us to develop the ideas in depth. articulation. In osteopathic literature this is known as the
sphenobasilar symphysis (S.B.S.). The articulation is not the
Hyperflexion and Hyperextension: cause of the problem but is a reference point to describe the
A Comparison variations in skull formation types. This articulation in the
In our previous article we outlined the pattern of rhyth- skull acts as a stress breaker, where a shift or adjustment
mic movement of the cranium and we touched on the phe- can occur in order to accommodate strain in the overall sys-
nomenon of cranial distortion or strain which may develop. tem, comparable to the action of the keel of a ship.
The challenge for the dentist is to understand how this distor- In order to demonstrate this process we have, in this arti-
tion of the cranial base structures can relate to malocclusion. cle, combined an initial examination of the first two of the
The availability of the lateral skull radiograph has seven cranial strains to be discussed in this series. By compar-
encouraged many attempts to identify various features of ing them side by side, the dramatic contrast highlights the
the cranial base that might influence facial structures. These need to understand and include the characteristics of the var-
have recently been reviewed by Andrea et al.3 Most cephalo- ious strains in our observation of patients.
metric analyses incorporate various parts of cranial base The flexion/extension movement of the cranium centers
structures into their evaluation or use them for superimposi- in the sphenobasilar symphysis. A common pattern of distor-
tion purposes, but this is of limited value in diagnosis. tion or strain is where there has been an exaggerated movement
The most interesting attempt to correlate cranial form into either flexion or extension and this becomes a persistent
with facial and dental features is that described by Enlow feature (Diagrams 1 and 2). These strains are called hyperflex-
and Hans.4 They use the Cephalic Index, an anthropologi- ion and hyperextension. While there may be a hereditary
cal technique for measuring skulls. This gives rise to the component they can also develop during the birth process.
familiar grouping of dolichocephalic (long head), brachy- They may even be imposed in utero or by trauma subsequent
cephalic (broad head), and mesocephalic (intermediate to birth.7 Accompanying each strain pattern is a characteristic
head). This classification holds up in broad ethnic terms,5 group of cranial, facial, dental and postural features.
but as Enlow et al readily point out, there are wide varia- Figures 1 and 2 show full-face and profile views of rep-
tions within each group. While the Cephalic Index has resentative hyperflexion and hyperextension individuals.
merit in identifying ethnic variations, there are serious prob- These will now be discussed.
lems in attempting to use it as a basis for understanding
malocclusion. The purpose of any classification should be Full Face Characteristics
to clarify a subject and thereby assist the clinician in his Cranial outline: In the hyperflexion example the later-
approach to diagnosis and treatment. Unfortunately, the al expansion of the skull has brought about a flattening of
use of the Cephalic Index can lead to complex and at times the cranium along the sagittal suture and a widening of the
contradictory conclusions when applied to malocclusion. cranium laterally. In the hyperextension example the lateral
In contrast, the classification developed by the osteo- contraction of the cranial bones leads to an elevation along
pathic profession has proved to be very practical from sever- the sagittal suture and a narrowing of the cranium.
al aspects. It pinpoints the underlying etiology of the cra- Ears: As the skull expands laterally in hyperflexion, the
nial/facial variations. It explains the presence of asymme- squamous portion of the temporal bones rotate outwards. The
tries, which are present in every individual. It enables a effect of this is to carry the ears laterally giving the flared
highly specific diagnosis to be made for each patient. It pro- appearance seen in this individual. Since the axis of rotation
vides a systematic approach to treatment planning by recog- around which the temporal bone rotates runs diagonally to the
nizing the contribution made by the cranial structures. cranial mid-line, the glenoid fossae tend to move distally as the
The brilliance of Sutherland’s achievement6 was not just ears go laterally. This in turn carries the mandible distally. This
to recognize that the skull moves but that the key to identify- feature will be discussed in more detail in the next article.
ing craniofacial variation is the relationship between the One ear may be more flared than the other. The more
sphenoid and the occiput. With this insight the relevance of flared ear indicates that the temporal bone is more outward-
the cranial base to malocclusion can be understood. ly rotated on that side. The result is that the mandible is
Essentially, we are changing our focus away from diag- carried back more on that side and thus is displaced
nosing and categorizing the arrangement of teeth within towards the more flared ear. This relationship of flared ear
the oral cavity. Think instead of describing the dental struc- to distally displaced mandible is a consistent finding that
tures as components within the entire cranium, responding can be applied as a diagnostic clue. It may occur unilateral-
to differences in the overall morphogenetic pattern. ly or bilaterally depending on the underlying strain pattern.

24 IJO • VOL. 16 • NO. 1 • SPRING 2005

 Variations such as one ear being higher than the other or
Diagram 1. Hyperflexion
placed more forward than the other on an anteroposterior
plane will be discussed in relation to other strains. In the
hyperextension example, the squamous parts of the tempo-
ral bones move inwards carrying the ears closer to the skull.
The glenoid fossae are placed forward tending to give a
prognathic mandible.
Mid-facial Features: The mid-face shows striking dif-
ferences. The hyperflexion example has a wide face with
well-developed malar processes; the eyes are set wide apart
and the nares are also wide. In the hyperextension example
the mid-face is obviously constricted while the malar
Diagram 2. Hyperextension processes and the lower borders of the bony orbits are
retruded. This gives a mid-facial flatness or even a concave
mid-face. The eyes are close together and the nares are con-
stricted. The maxillae are carried up and back due to the
greater wings of the sphenoid rotating upward and back-
wards. There may be constriction of the nasal airway as
there is in this individual.
Lower Face: In the hyperflexion example there is a
reduced lower facial height. There is a rolled contour of the
lower lip. In the hyperextension individual there is an
increase in lower face height tending toward an open bite of
skeletal origin. Lips may be apart at rest due to the
increased height of the lower face.
Profile: The contrast in facial features between these
Figure 1
two cranial strains is also apparent in profile view. Taken as
a whole, the hyperflexion head is shortened in an A-P plane
and the posterior cranial outline is more vertical. The
hyperextension head is elongated from the posterior upper
outline down towards the mandible. The mandibular retru-
sion is obvious in the hyperflexion example, as is the
mandibular prognathism in the hyperextension example.
This appearance of mandibular prognathism is increased by
the maxillae also being drawn upward and backward.
We have deliberately delayed discussing the malocclu-
sions accompanying these two strains. This is to shift priori-
ties away from identifying the Angle classification as the
initial step in diagnosis. The dental characteristics should be
seen as a reflection of the craniofacial structures.
Eventually, with experience, the Angle classification
Figure 2
becomes almost redundant.
As readers may have anticipated, the hyperflexion indi-
vidual has an Angle Class II, Division II malocclusion and
the hyperextension subject has one type of Angle Class III
malocclusion, with a high narrow palate and bilateral cross-
bite. Both these craniofacial variations will be examined in
more depth in following articles as to how they come about,
how to recognize them and how to approach treatment.
Osteopaths diagnose the various cranial strains primari-
ly by palpation of the cranium. Handoll,8 an osteopath,
claims that the facial features cannot be used to determine
cranial strains. However, after eight years of clinical appli-
cation of facial evaluation we are confident that the visual

IJO • VOL. 16 • NO. 1 • SPRING 2005 25

approach has validity. Many of the patients we have diag- References
nosed in this way have also had an independent assessment 1. Kuhn, T.S., The Structure of Scientific Revolutions, 2nd Edition,
by osteopaths. Their findings support our hypothesis. University of Chicago Press, 1970.
2. Obtainable from Dubking Conference Videos, Telephone:
A reasonable question is why we should make the (210) 979-8779 or E-mail: www.dubking.com.
effort to understand the range of cranial strains which can 3. Andrea L., Leite L., Prevatter T., King L. “Correlation of the
occur. It is not just a matter of learning osteopathic termi- Cranial Base Angle and its Components with other
nology. It involves a major shift in almost every aspect of Dental/Skeletal Variables and Treatment Time.” Angle
orthodontic diagnosis and treatment. The reward is to reach Orthodont. 74 361-366, 2004.
4. Enlow D.H., Hans, M.G. Essentials of Facial Growth. Pub. W.
a far more penetrating understanding of how a malocclu- B. Saunders Co., 1996.
sion develops. This understanding leads to a radical change 5. Kuroe K., Rosas A. Molleson T. “Variations in Cranial Base
in treatment objectives and in the choice and delivery of Orientation and Facial Skeleton in Dry Skull Samples from
force systems. This results in more effective and long lasting Three Major Populations.” Europ. J. Orthodont. 26: 201-207,
2004.
benefits in our patients’ overall health, not just the correc-
6. Magoun H.I. Osteopathy in the Cranial Field. 3rd Ed. 1976.
tion of their malocclusion. Available from Sutherland Teaching Foundation, 4116
Hartwood Drive Fort Worth TX 76109.
7. Frymann V.M. Collected Papers 1998. Ed.
By H.H. King for the Amer. Acad. Osteopathy,
3500 DePauw Blvd. Suite 1080 Indianapolis IN
46268-1136.
8. Handoll N. The Anatomy of Potency.
Osteopathic Supplies Ltd. 2000. Distributed in
North America by Stillness Press L.L.C. Tel.
(503) 265-5002

Dr. James is an
Orthodontic Specialist in
Barrie, Ontario. A major
part of his practice is con-
cerned with the manage-
ment of temporomandibu-
lar joint and cranioman-
dibular disorders. His
Gavin A. James, MDS, FDS interest in cranial move-
ment has developed as a
part of a more comprehensive examination of the
problem of head and neck pain.

Dr. Strokon is a general

dentist in Ottawa,
Ontario. He received his
dental degree from the
University of Western
Ontario in 1972. For the
past twenty-five years he
has taken an interest in
Dennis Strokon, DDS treating symptomatic
patients using both restora-
tive and orthodontic techniques in his practice. Dr.
Strokon and Dr. James lecture on the philosophy,
treatment concepts and design of the ALF appli-
ance.

26 IJO • VOL. 16 • NO. 1 • SPRING 2005