Orthodontic
problems |
Fabio Savastano, M.D., M.S. Orth
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Orthodontics or more specifically orthognathodontics
is the branch of dentistry that studies and corrects teeth malpositions,
both from aesthetical and functional viewpoint, so that our mouth
has not only a beautiful look but also a "functioning" occlusion.
The conformation of face bones and the size (sometimes the number)
of teeth are common problems associated with the need for orthodontic
care. Maxillo-facial surgery is sometimes the only issue to the
solution of this problem. As already seen elsewhere in these pages,
improper alignment of the dental arches may be a primary cause of
gnathologic problems and Mother Nature, too, may force our
mouth to a physiologically distorted adaptation, resulting in pathologic
disorders .
A correct mastication model shall respond to the following three
basic principles:
1) The upper molars and premolars shall overlap the lower by about
half a tooth.
2) The upper central incisors shall overlap the lower by about 1/3
of their height.
3) All teeth of the upper and lower jaws shall meet with two antagonists,
i.e. the teeth of the opposite arch. Just like the bricks of a wall,
probably providing more stability to the "palissade". .
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A
proper centric occlusion shall have the following features:
the upper teeth slightly externally overlapping the lower and the
incisors overlapping their antagonists by about 1/3. Each tooth
shall meet with two teeth of the opposite arch.
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Deep
bite occurs when the upper incisors deeply - sometimes completely
- overlap the lower and are bent backward. This situation may affect
jaw movement, forcing the mandible to recede.
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Deep
bite also occurs when the upper incisors deeply - sometimes
completely - overlap the lower and are projecting. This situation
inhibits closing the lips and forces the tongue to an abnormal activity
whenever saliva is swallowed.
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Open
bite occurs when there is much space between upper and lower
incisors. Besides making lip seal impossible, this disorder also
involves "infantile" swallowing, in which the tongue pushes violently
against the front teeth, probably in an attempt to find a closure
providing the depression required for swallowing.
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Dental
crowding: this "disorder" usually stems from a discrepancy
between space available in each jaw and the size of the teeth. Apart
from the fact the "one-to-two teeth" contact is missing and causes
a real occlusion instability, there is poor specific dental function.
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In
this case, the right canine guide is missing whereas the left is
reversed. These conditions may well be predisposing factors for
bruxism and mandibular joint overload. The muscles of mastication
are tense.
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Edge-to-edge
occlusion occurs when the "one-to-two teeth" contact is
missing, which causes an unstable occlusal contact. Many patients
refer that they feel like "standing on eggs". Frequently the patient
has the impression not to fit a stable bite and attempts to compensate
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the problem by wedging his/her tongue so as to form a sort of resting
pad. It ensues that its border becomes indented and exhibits the
impression of the teeth. Swallowing is abnormal and associated with
a severely altered and tense facial musculature.
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Dental
extrusion:
occurs when antagonist teeth are since long missing and the remaining,
which do not meet with anything, have grown to close the whole existing
space and sometimes touch the gingiva of the opposite arch.
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Under
these conditions, the posterior masticatory plane - which is a real
support for the joints - is completely missing. This will result
in compression, early wear and derangement of the disk. The ipsilateral
face muscles are particularly tense and overstrained.
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Embedded
dental extrusion: it occurs when antagonist teeth are since
long missing and the remaining, which do not meet with anything,
have grown embedding in the opposite mucosal area.
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Under
these conditions, the range of masticatory functional movements
of the mandible is severely impaired. This will cause an abnormal
muscle contraction which will restrain jaw movement, to prevent
it from hitting against the adjacent teeth. The face muscles are
particularly tense and overstrained
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Monolateral
cross-bite occurs when there is an abnormal reversed occlusal
relationship on one side. This will result in a deviated smile
midline and quite often the mandible deviates, too.
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The
figure shows a deviation to the right. This problem may easily cause
joint overload on the deviated side and asymmetric muscular contracture.
Visually, the chin, too, deviates to the right.
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Bilateral
cross-bite occurs when there is an abnormal reversed occlusal
relationship of teeth on both sides, except for the two front incisors
of the upper arch.
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The
result is that symmetry may be maintained but the "scissors-type"
occlusion will limit the range of functional movements of the mandible
and cause spasm to the facial muscles. |
Autotest
problemi Ortodontici
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Si
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No
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1.
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Do
you have a deep overbite with retruded incisors? |
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2.
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Do
you have a deep overbite with protruding incisors? |
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3.
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Do
you have an open bite? |
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4.
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Do
you have severe dental crowding? |
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5.
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Do
you have an edge-to-edge occlusion at least monolaterally? |
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6.
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Do
you have a dental extrusion in the posterior quadrant? |
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7.
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Do
you have an embedded dental extrusion? |
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8.
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Do
you have a monolateral cross-bite? |
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9.
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Do
you have a bilateral cross-bite? |
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10.
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Do
you have a "scissors" tooth? |
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Examine
these figures carefully and answer the above questions. If you identify
yourself in at least two of these situations, you are probably affected
by a tooth borne gnathologic disorder. If your answer to either
question is YES, you might be more predisposed to gnathologic disorders
than a person with no malocclusion problems. This might be related
to temporomandibular joint disorders like popping, clicks, locks,
restricted opening, stuffed ears, vertigo or head and neck pains,
such as headaches, wryneck, cervical pain.
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