Children are a special
case because they are growing. This makes them ideal subjects
for orthopedic intervention. ("Ortho" means to straighten
and "pedo" means child.) Because they are fairly pliable
and the bone is relatively soft and always growing and changing,
it is easy to guide the bone growth in children through external
means. An oak tree, tied in a knot when it is a tiny sapling,
will grow in a hundred years into a huge oak tree with a knot
tied in its trunk. What was possible when the tree was immature
becomes impossible in maturity. (There is some argument about
whether the movement of children's teeth is actually faster
than that of adults, but there is no argument about the ease
of movement due to the growth factor.)
As every mother knows,
their children grow faster at some ages than at others. Therefore,
orthodontic practioners want to time their treatments for the
ages when the child is mature enough to cooperate with treatment,
and also when the bone is growing most rapidly. The optimum
age for beginning treatment depends upon the specific deformity
that the orthodontic practioner needs to correct, but the best
age for evaluation of that specific deformity is usually age
7 because that is the age when both factors tend to coincide
for the treatment of certain skeletal deformities. A major growth
spurt takes place at puberty, and orthodontists like to take
advantage of this as well. When deformities are assessed early
and treated prior to the time that they have fully developed,
we have "intercepted" the problem and this is referred
to as interceptive orthodontics.
For those patients who have
clear indications for early orthodontic intervention, early
treatment presents an opportunity to:
1- guide the growth of the jaw,
2- regulate the width of the upper and lower dental arches (the
arch-shaped jaw bone that supports the teeth),
3- guide incoming permanent teeth into desirable positions,
4- lower risk of trauma (accidents) to protruded upper incisors
(front teeth),
5- correct harmful oral habits such as thumb- or finger-sucking,
6- reduce or eliminate abnormal swallowing or speech problems,
7- improve personal appearance and self-esteem,
8- potentially simplify and/or shorten treatment time for later
corrective - orthodontics,
9- reduce likelihood of impacted permanent teeth (teeth that
should have come in, but have not), and
10- preserve or gain space for permanent teeth that are coming
in.
The congenital
skeletal deformities
Class
I
Congenital skeletal deformities
are conditions occurring at birth and are usually caused by
genetic factors. In order to understand what constitutes a deformity,
however, it is necessary to understand what constitutes the
generally accepted standards of normality.
In
the diagram, the central image shows the most normal facial
profile. In dentistry, we look at the way the top and bottom
teeth come together to determine the exact nature of the profile.
This type of profile is called a Class I occlusion (occlusion
means the way the top and bottom teeth line up together) and
it is characterized by the relative positions of the upper and
lower first molars (the molars are the large back teeth, and
the first molars are the large back teeth that are furthest
forward). The detail of the teeth under the main images show
how the first molars line up in each case. From the point of
view of appearance, the class I occlusion yields the best profile.
Class I occlusion is considered the standard for "normality".
Class I deformities are generally the result of crowding, extra
space, or from developmental deformities.
Class
II
The image to the right
shows the class II profile. This is probably the most common
skeletal deformity (deviation from "normal"). This
occlusion yields a "weak" chin, or retruded chin profile.
Extreme cases give an "Andy Gump" appearance. While
this represents a deformity, in fact it can be quite attractive
on some women.
It
can have the overall effect of drawing attention to the eyes,
and can account for the "all eyes" attractiveness
that some women possess. No matter what you think of the appearance
of the profile, this occlusion does leave the patient with functional
problems involving the position of the front teeth (incisors).
The lower incisors frequently do not touch the upper incisors
when the back teeth are together, and this allows the lower
incisors to erupt up into the gums at the roof of the mouth,
and allows the top incisors to erupt into an unattractively
"long" and "gummy" appearance, well beyond
the edge of the top lip.
ClassIII
Class III deformities
yield a "prognathic", or "strong chin" appearance.
This could be caused by over development of the lower jaw, or
by underdevelopment of the upper jaw . This profile is not usually
considered attractive on women, however it can be an asset to
men, depending on the image they wish to project.
It
is associated with the "tough guy" or "bulldog"
image projected by the 1940's movies, and gives a singularly
masculine appearance that we associate with football players
today. As with class II occlusions, this profile is associated
with functional and esthetic problems. Since the lower incisors
are located in front of the upper incisors, they too can erupt
to unattractive lengths. This profile can be associated with
a "smooth cheekbone" appearance and a tendency not
to show the upper front teeth when talking or even when smiling.
Biting can be a real problem for these people in extreme cases,
because while class I and II profiles can stick their lower
jaws out further to bite off a piece of food, it is impossible
for the class III profile to draw his lower jaw any further
back to make the front teeth meet.
What
is all that "equipment" that the patient wears during
treatment?
Orthodontic practioners
use lots of complicated wires, jack screws, elastics and "retainer-like"
appliances to accomplish their orthodontic/orthopedic goals.If
you have specific questions regarding the purposes of things
like headgear, bionators, palatal expansion devices and various
other stuff that looks like it was invented by someone in Dracula's
dungeons, the best thing to do is to corner your orthodontist
and ask why you or your child needs it. He or she knows your
child's needs specifically and can speak directly to your concerns.
If this is not possible, click on the icon to the right to proceed
to a site that goes into the technical reasons for these devices.
This link brings you to an internal page at the site with a
good navigation bar that allows you to go directly to your point
of interest.
The
developmental deformities
Developmental deformities
treated by orthodontist practioners are caused by environmental
factors such as thumb sucking and lip habits, as well as by
other physical errors such as an inability to breath through
the nose due to sinus and allergy problems, or the failure of
some of the teeth to develop. These deformities are often associated
with narrow upper arches, and/or an open anterior bite such
as that seen in the image of the thumb sucking habit below.
This category also includes crowded, crooked teeth since in
this case there is a discrepancy between the size of the teeth
and the space available in the dental arches to accommodate
them. Of course, all these problems often occur in combination
and there is frequently no neat division between them in any
given case. Therefore, every case is unique and must be handled
with completely different treatment plans.
Thumb
sucking
Thumb sucking is a habit
that will generally subside on its own. By the time the child
is in grade school, he or she wants to stop because it has already
become a social liability.
If stopped by age 6 or
7, even the open bite pictured above will revert back to normal.
Upon occasion, a child will want to stop, but be unable to break
the habit. Under these circumstances, it can be helpful to insert
a fixed (not removable) habit breaking device as a "reminder"
not to put the thumb into the mouth. These work well provided
that the child wants to stop the habit. If the habit persistspast
the age of 12, the skeletal deformity you see on the left can
persist for the rest of that person's life.
The picture at the left
of this page is of a child who will likely develop a open bite
as a result of a persistent tongue thrust habit which is similar
to the habit of "reverse swallowing" in which the
tongue is pushed out between the teeth every time the child
swallows. Note also that the habit of persistently biting or
sucking on the lower lip can produce similar deformities. These
habits are all handled with their own habit breaking appliance
designs.
Mouth
breathing
The normal development
of the oral structures depends upon the ability of the child
to breath through the nose without obstruction, especially at
night. This does NOT mean that if your child gets an occasional
cold and can't breath through his nose he will grow up with
oral abnormalities. However, chronic obstruction of the nasal
airway due to deviated septum, persistent allergies or other
anatomic abnormality will tend to cause the roof of the mouth
(the hard palate) to rise and the back upper right and left
teeth to collapse toward each other. We call this condition
a constricted arch. The teeth are arranged in arches.
The picture on the right
is a model of a constricted arch. The model on the left has
a more normal arch form. A patient with the teeth on the right
will have a smile that shows mostly the two prominent front
teeth, with the others in shadow. The one on the left shows
a normally shaped archform resulting in a broader smile
Crossbites
In most instances, the
constriction of the upper arch is accompanied by some degree
of constriction in the lower arch caused by the tilting of the
lower teeth toward the tongue. However, the degree of lower
constriction is not enough to keep the upper and lower back
teeth in the correct relationship with each other. This produces
a condition known as crossbite in which the top back teeth hit
on the inside cusps of the lower back teeth instead of on the
outside cusps which is the normal relationship.
Figure
A shows a schematic view from the front of the mouth with teeth
in a normal biting situation. Figure B shows the teeth in a
crossbite situation. Posterior crossbites like this can have
pronounced effect on the overall facial appearance, especially
when they are unilateral (on one side of the mouth only). When
a unilateral posterior crossbite is present in a young person,
it can cause asymmetric development of the facial muscles and
the jaw joint which means that one side of the face may grow
larger than the other.
Crowded
and missing teeth
Nature tries to fit the
teeth into the space available. The teeth always end up in their
most stable position within the dental arch, whether they are
crowded, or have extra space between them. Stability is the
name of the game. There is always a balance between the various
forces that affect any given tooth, as well as the amount and
position of bone available, that helps determine where that
tooth is most stable. If a dentist tries simply to move the
teeth into better looking positions, Nature may move them right
back where they started. This is why an orthodontc practioner
must play certain tricks to make sure the local forces effecting
each tooth will cancel each other out after treatment so that
the tooth will stay put once it is moved.
This is why the orthodontic
practioners must usually treat both upper and lower teeth, even
if only the appearance of the top teeth are of concern to the
patient. Unless the position of the lower teeth coincide with
the position of the uppers, the biting forces produced by the
ill fitting lowers will create instabilities that will move
the uppers back into crooked positions over time. This is also
the reason that the orthodontist will order the extraction of
some teeth. The extra room created by the removal of these teeth
changes the stability equation in favor of the preferred new
tooth positions.
In
the diagram, the central image shows the most normal facial
profile. In dentistry, we look at the way the top and bottom
teeth come together to determine the exact nature of the profile.
This type of profile is called a Class I occlusion (occlusion
means the way the top and bottom teeth line up together) and
it is characterized by the relative positions of the upper and
lower first molars (the molars are the large back teeth, and
the first molars are the large back teeth that are furthest
forward). The detail of the teeth under the main images show
how the first molars line up in each case. From the point of
view of appearance, the class I occlusion yields the best profile.
Class I occlusion is considered the standard for "normality".
Class I deformities are generally the result of crowding, extra
space, or from developmental deformities.
It
can have the overall effect of drawing attention to the eyes,
and can account for the "all eyes" attractiveness
that some women possess. No matter what you think of the appearance
of the profile, this occlusion does leave the patient with functional
problems involving the position of the front teeth (incisors).
The lower incisors frequently do not touch the upper incisors
when the back teeth are together, and this allows the lower
incisors to erupt up into the gums at the roof of the mouth,
and allows the top incisors to erupt into an unattractively
"long" and "gummy" appearance, well beyond
the edge of the top lip. 
It
is associated with the "tough guy" or "bulldog"
image projected by the 1940's movies, and gives a singularly
masculine appearance that we associate with football players
today. As with class II occlusions, this profile is associated
with functional and esthetic problems. Since the lower incisors
are located in front of the upper incisors, they too can erupt
to unattractive lengths. This profile can be associated with
a "smooth cheekbone" appearance and a tendency not
to show the upper front teeth when talking or even when smiling.
Biting can be a real problem for these people in extreme cases,
because while class I and II profiles can stick their lower
jaws out further to bite off a piece of food, it is impossible
for the class III profile to draw his lower jaw any further
back to make the front teeth meet. 
If
you have specific questions regarding the purposes of things
like headgear, bionators, palatal expansion devices and various
other stuff that looks like it was invented by someone in Dracula's
dungeons, the best thing to do is to corner your orthodontist
and ask why you or your child needs it. He or she knows your
child's needs specifically and can speak directly to your concerns.
If this is not possible, click on the icon to the right to proceed
to a site that goes into the technical reasons for these devices.
This link brings you to an internal page at the site with a
good navigation bar that allows you to go directly to your point
of interest.
past
the age of 12, the skeletal deformity you see on the left can
persist for the rest of that person's life.
Figure
A shows a schematic view from the front of the mouth with teeth
in a normal biting situation. Figure B shows the teeth in a
crossbite situation. Posterior crossbites like this can have
pronounced effect on the overall facial appearance, especially
when they are unilateral (on one side of the mouth only). When
a unilateral posterior crossbite is present in a young person,
it can cause asymmetric development of the facial muscles and
the jaw joint which means that one side of the face may grow
larger than the other. 
