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This is a case where we have space just in the midline between the two maxillary incisors.
It's probably due to a discrepancy between the arch length and the size of the teeth.
Often timesů people think the ideologic cause of such a midline diastema is the frenulum.
As you can see the frenulum in this case does not blanche the tissue between the incisors
when we raise the upper lip. Most of the evidence supports the fact that the frenulum is not
related to the cause in that if we close the space and remove the frenulum it seems to
open the same amount as if we hadn't removed the frenulum.
The treatment procedures that can be used in such a case would be to put orthodontic
bands on the first molar teeth and bands on the four incisor teeth. These could be done
either with conventional bands or the new direct bonded acrylic brackets. This might
be recommended if we wanted to move teeth sideways along an arch wire or if we felt
that we needed control over the root apices. However, in this case, we feel there is sufficient
room to merely tip the teeth posteriorly and close the space in this manner. In which case,
Hawley appliance that we will show you after going off-camera for a while is the appliance
of choice in that we also run into a retention problem with any midline closure and our choices
of retention after closing the space would either be pin-ledge inlays on the lingual
surface of the maxillary incisor teeth which would hold the teeth together once the space
has been closed or periodic wearing of a retainer, a removable like a Hawley perhaps once a week
for the duration of the time that the teeth tend to move apart which may be actually a
lifetime permanent retention. Because we have room to tip the teeth back I'd like to demonstrate
that at this moment.
If you can look in the mirror, you see that there is space behind the maxillary incisor
teeth. There is no contact in centric occlusion or centric relation. I'll position her mandible
in centric relation at this moment. Just relax Carla.
Okay back down the other way.
If we can have that same close-up.
So the space is available for us to tip the maxillary incisor teeth palatally and the
angulation of the tooth is such that we can afford a little tipping. This time we'll go
off-camera and come back with the appliance and show you the insertion and the activation.
We return back on camera with the Hawley appliance completely constructed. I'd like to point
out that we used a circumferential labial wire. This wire must be embedded firmly in
the acrylic so as not to pull during the length of time the appliance is worn. By contacting
the terminal molar tooth just under the distal height of contour we gain the posterior retention
that we need for the appliance. The wire is of an old three, six,ů .036 diameter size
that's made with loops just distal to the cuspids and they should be of sufficient length
to give us enough wire for gentle activation over the maximum length that we can use. It
contacts the incisor teeth.
And due to the length of the wire we put an O-1-6 wire between the bicuspids to stabilize
the labial arch wire and occlusal gingival direction.
Looking at the models we'll refresh you on the fact that we're trying to tip the maxillary
incisor teeth to the lingual. We have space available.
Therefore we need the wire contacting both central incisor teeth and sitting passively
inside the mouth at first before activation.
We'll try the appliance at this time to make sure it fits properly.
The appliance does fit properly. So we'll remove the appliance because we'll need to
remove the acrylic just lingual to the maxillary incisor teeth.
This needs to be done so that the acrylic bur lies parallel to the lingual, the acrylic
that is adjacent to the lingual surface of the maxillary teeth.
After removing the acrylic, seat the appliance back on the cast to make sure that we've removed
enough acrylic just lingual to the incisor teeth. We've outlined the free gingival margin
behind the incisor teeth with a pencil and as you can see there is a space behind maxillary
teeth.
This time we're ready to activate the appliance. For the first appointment we use a small activation,
a three-prong plier is ideal for this procedure. By placing theů plier at the top of the loop
we can squeeze the appliance gently which moves the labial bow towards the lingual surface.
You need to do this on both sides and that move lowers the labial bow across
the anterior segment. So we need to make a compensating bend in the anterior portion
of the bow. These are general activations. We'll have the patient back every three weeks
to slightly activate the appliance again until the space is closed.
Carly, do you feel any pressure on any of the teeth?
Right here in the front.
We do want the patient to tell us that she's experiences a little pressure on the incisor
teeth and not on any of the other teeth. It is not uncommon after an adjustment to perhaps
have the loop around the cuspid area impinge upon the gingiva and in this case a small
compensating bend should be made so that the appliance is comfortable on all the teeth
except for a slight feeling of pressure on the incisor teeth. If the appliance is not
comfortable and the patient will not wear it and the appliance must be worn 24 hours
a day except at meal time and sports activities.
When the patient removes the appliance at mealtime we instruct him to clean the appliance
either with lukewarm water or cold water and a tooth brush. We also give them a case to
put the appliance in at mealtime or whenever it is removed from the mouth so that it does
not get lost or broken. Before the patient leaves the office she should be instructed
on the proper way to insert and remove the appliance and practice this two or three times.
Carla would you put this in for us?
I'll work with Carla on the insertion and the removal and bring her back when the case
is completed.
It's been six weeks since we delivered the Hawley retainer to Carla Brown to close a
midline diastema.
During that time we made two adjustments. Now I'd like to show you our end result.
As you can see the space between the central incisor teeth is fully closed and we are still
free from occlusal interferences. This same Hawley appliance will now be used as our retention
appliance. The program will vary slightly but chances are we will have her wearing the
appliance full-time for three months. Every other day for the second three months, every
third day for another three months and then only as it's required to keep the space closed.
The difficulty with treating a midline diastema is the retention part of the treatment. The
space closes fairly easily but there's a great tendency for it to open so in almost every
case where we treat midline diastema we inform the patient of the possibility of permanent
retention.
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