3. 1935-1949 Charles Sidney Burwell
Dr. Burwell was a cardiologist who specialized
in circulation changes associated with heart
disease. He is credited with bringing attention to
obstructive sleep apnea syndrome.
In 1944, Dean
"Half of what we are going to teach you is
wrong, and half of it is right. Our problem is
that we don't know which half is which."
8. Adaptation
Mechanisms of Biological System when it exposed to many influences
Biological adaptation the adaptation
of living things to environmental
factors for the ultimate purpose of
survival, reproduction, and an optimal
level of functioning.
9. Compensation
Mechanisms of Biological System when it exposed to many influences
1. the counterbalancing of any defect of structure or
function.
2. a mental process that may be either conscious or
unconscious defense mechanism by which a
person attempts to make up for real or imagined
physical or psychological deficiencies.
3. in cardiology, the maintenance of an adequate
blood flow without distressing symptoms,
accomplished by such cardiac and circulatory
adjustments as tachycardia, cardiac hypertrophy,
and increase of blood volume by sodium and
water retention.
11. Dental treatment, including
functional prophylactic measures
Physiological structures or
progressive adaptation
Compensation
No definitive measures that affect the
occlusion without further diagnostic
clarification
Dental treatment that will not upset the
fragile equilibrium
Cause-related functional therapy prior
to definitive dental treatment
Decompensation
or
regressive adaptation
Functional therapy prior to definitive dental
treatment
No occlusal functional therapy if there
are no occlusal etiological influences
Symptomatic functional therapy for the
transition to a compensated status
1
3
2
12. The Role of Dentistry in Craniofacial Pain
psychological factors occlusal factors
Vs
21
13. Every patient with head and neck pain should be seen by a
dentist in order to clarify the following questions:
Do the symptoms arise from a structure in the masticatory
system (presence of a loading vector)?
Is the loading vector related to the occlusion?
Can the occlusion-related portion of the total loading vector be
reduced with reasonable effort and expense?
Would symptomatic treatment in the dental office be
reasonable?
The Role of Dentistry in Craniofacial Pain
27. Lateral Pterygoid
Muscle
1 Upper head
2 Lower head
EMG activity of the
muscles of
mastication at rest
and during jaw
EMG activity during
grinding of the teeth
Jaw-OpeningMucsles
?
28. the muscle becomes segmented into three
parts in week 12 of embryonic development
to form an upper (1), middle (2), and lower (3)
Lateral Pterygoid
Muscle
Jaw-OpeningMucsles
29. the upper head always inserts on the condyle (1),
and in 60% of joints it also inserts into the
anteromedial portion of the disk-capsule complex
(gray). The lower head always inserts into the
Jaw-OpeningMucsles
30. MRI showing the lateral pterygoid muscles (1)
in the horizontal plane.
Lateral Pterygoid
Muscle
Jaw-OpeningMucsles
31. Muscle origins and insertions on the
posterior mental protuberance
Histological preparation of the insertion of the
digastric muscle. The insertion of this muscle is primarily
periosteal, but it does have some regions of cartilaginous
Jaw-OpeningMucsles
32. The tendon
inserts on the
coronoid process
by means of
cartilaginous
structural
Histological
preparation of the
insertion of the
lateral pterygoid
muscle in the
pterygoid fovea.
33. Force Vectors of the
Muscle vectors in the
frontal plane
Muscle vectors in the
sagittal plane
36. Influence of head and body posture on the mandible . As an
example, the sternocleidomastoid muscle is always active
during bruxism; however, an activity level of 50% is necessary
in the masseter muscle before a 5% level is reached in the
37.
38. articular eminence (1) and at the far left is the external auditory meatus (2). In the posterior
portion of the fossa the squamotympanic fissure (3) is found laterally, and the
petrosquamous (4) and petrotympanic (5) fissures are found medially.
39. These fissures are ossified in more than 95% of patients with disk displacement, whereas in joints without
disk displacement normal fissure formation prevails (Bumann et al. 1991).
Squamotympanic fissure is
completely ossified
40. Inferior view of the temporal cartilaginous joint
surface and capsule attachment
41. Positional Relationships of the Bony Structures
The physiological (i.e. centric) condylar position is defined as the most
anterosuperior position with no lateral displacement (arrows), this
position depends upon the basic neuromuscular tonus.
Sagittal relationships
42. By applying artificial traction on the specimen, the anterior portions of the upper and lower joint
capsules (arrows) have been made more clearly visible. Posteriorly the joint spaces are bounded
by the superior stratum (1) and inferior stratum (2). The posterior capsule wall lies behind the
genu vasculosum. The type-Ill receptors of the capsule are only activated by heavy tensile loads
on the lateral ligament and serve then to stimulate the elevator muscles (Kraus 1994)
Joint capsule in the
sagittal plane
44. Overdistended capsule
Anterior disk displacement requires not only a stretching of the inferior stratum
(1), but also a distention of the lower anterior wall of the joint capsule (arrows).
However, because the connective tissue of the anterior capsule wall is much
looser, disk displacement depends almost exclusively on posterior loading
vectors and the adaptability of the inferior stratum. A downward movement of the
condyle as shown here without downward movement of the disk is possible only
with extensive stretching of the inferior stratum.
45. (Solberg et al, 1985, Bermejo et al. 1992) identify two separate
connective tissue structures for attachment to the condyle, one for
the disk (1) and the other for the capsule (2).
Diskandcapuleattachmentsinthe
frontalplane
"diskocapsular system" (Dauber 1987)
46. Dr.Samer F.Mheissen
Macroscopicanatomicalpreparation
With the jaws closed the bilaminar zone (1) fills the space
posterior to both the pars posterior (2) and the condyle (3).
The inferior stratum stabilizes the disk on the condyle in
the sagittal plane. An overextension of the bilaminar zone
through posterosuperior displacement of the condyle is an
essential precondition for an anterior disk displacement to
occur.
With the mouth open the genu
vasculosum (1) fills with blood. The
superior stratum (2) and inferior
.stratum (3) can be easily identified
49. Anterosuperior aspect of the
disk-condyle complex
Anterolateral aspect of the disk-
condyle complex
50. With the jaws closed the bilaminar zone (1) fills the
space posterior to both the pars posterior (2) and
the condyle (3). The inferior stratum stabilizes the
disk on the condyle in the sagittal plane. An
overextension of the bilaminar zone through
posterosuperior displacement of the condyle is an
essential precondition for an anterior disk
displacement to occur.
With the mouth open the genu vasculosum
(1) fills with blood. The superior stratum (2)
and inferior stratum (3) can be easily
.identified
BilaminarZone
51.
52. Three Main Functions:
1. Stabilization
2. Guidance of Movement.
3. Limitation of Movement
Ligaments
What is the most important function ???
54. Lateral ligament
The lateral ligament (arrows). The initial rotation during an opening movement
is limited by the superficial part of the lateral ligament (von Hayek 1937, Burch
and Lundeen 1971). Further opening of the jaws can occur only after
protrusion has relieved tension on the ligament, following which the ligament
is again stressed by renewed rotation (Osborn 1989).
Situation with jaws closed
55. Lateral ligament
Situation with jaws open
Jaw opening is restricted by the length of the lateral ligament from its origin to its
insertion. However, if the condyle can slip past the apex of the tubercle (eminence), the
ligament (arrows) will no longer have this limiting effect. In addition, the lateral ligament
will now impede retrusive and laterotrusive movements of the condyle (Posselt 1958,
Brown 1975, Osborn 1989).
59. Initial phase
The condyle makes a rotational movement with a small translational component,
changing its position relative to the fossa only slightly. Because of the condylar
rotation, the disk moves posteriorly relative to the condyle. The only part of the
lateral pterygoid muscle that is active is its lower head (1).
Jaw-OpeningMovement
60. Intermediate phase
The disk moves anteriorly relative to the fossa, but posteriorly in relation to the
condyle. Tension becomes steadily increased in the superior stratum of the
bilaminar zone and in the lower anterior wall of the joint capsule. The inferior
stratum relaxes to the same extent. The venous plexus of the genu vasculosum
expands, creating a negative pressure, and fills with blood.
Jaw-OpeningMovement
61. The condyle reaches the maximum extent of its rotation and translation. The
translational component passively moves the disk farther forward, while the
rotation makes it lie farther posteriorly on the condyle. The superior stratum and
the lower anterior capsule wall are now stretched to their maximum. The
retrocondylar space is filled by the blood flowing into the genu vasculosum. The
inferior stratum is completely relaxed.
Terminal phase
Jaw-OpeningMovement
62. Initial phase
The upper head (1) of the lateral pterygoid muscle retards distal movement of the
condyle through eccentric muscle activity. The disk can only be passively guided
posteriorly. In the initial phase this is brought about by the tension in the elastic
superior stratum. A physiological positive pressure arises in the genu vasculosum
Jaw-ClosingMovement
63. Tension in the superior stratum steadily diminishes, and the disk, because of the
bulge of its pars posterior, is passively carried farther distally. A nonphysiological
increase of pressure in the genu vasculosum due to sympathetic or hormonal
influences would exert an anteriorly directed force on the disk (Ward et al. 1990).
This can lead to increased tension in the inferior stratum and flattening of the disk.
Intermediate phase
Jaw-ClosingMovement
64. Terminal phase
The inferior stratum becomes increasingly tense and finally prevents anterior disk
displacement in case the condyle moves too far distally. Anterior disk
displacement can occur only in the presence of an overstretched inferior stratum,
with or without flattening of the pars posterior (Eriksson et al. 1992).
Jaw-ClosingMovement
