Straight-Wire Appliance® has made articulators practical for orthodontists;
the quality of the occlusion can be evaluated more precisely than it can
be clinically; most patients want an occlusion that will pass articulator
scrutiny; approximately 500 orthodontists are now routinely using them;
their use leads to higher standards; when articulators are state-of-the-science,
they may discourage treatment by those not qualified; good dentists favor
referring to orthodontists that use articulators.
It is the first articulator system designed specifically for the needs of the
orthodontist; it can be used to help diagnose anterior border goals;
it is manufactured to tolerances of .005 of an inch; it is made of space-age
plastic which will not distort if dropped; it is as accurate as any
articulator with the same settings; it has mounting plates that slip
on/off (no screws) and are accurately interchangeable among all other
Simulator™ articulators; it can display all border treatment goals,
not just the distal; it is easy to use; it takes no more time to cast
mount than it does to prepare hand-held casts; it is inexpensive enough
to have one for every patient; it takes no more shelf space to fit 200
Simulator™ articulators than it does to hold 200 casts that are mounted
but not installed on an articulator. Gnathologists and Prosthodontists
need adjustable articulators to harmonize reconstructed teeth to deteriorating
TMJ's; orthodontists do not need adjustable articulators to construct
malposed teeth and to harmonize them with normal TMJ's.
will not willingly bite in CR if that is not where the teeth fit best.
clinical assessment of occlusal interfacing, even in CR, is suspect
because of tooth mobility. Mobile teeth that deflect or intrude when
a person clinches can result in the occlusion looking better than
range of border movements.
head and neck muscles.
directly with patients to learn their concerns.
lingual perspective of teeth.
casts are set on their trimmed distal borders, only the facial perspective
of the static occlusion can be seen. If the casts are held in the
hands without the wax bite, what is seen cannot be relied on because
all three vertical restraints are exclusively dental rather than two
of the three being the temporomandibular joints.
teeth interrelate when functioning cannot be assessed with hand-held
crowns from the lingual perspective.
does not come into play when impressions of each arch are made with
materials soft enough to not cause their deflection, and tooth positions
are recorded with wax softened enough that it will also not cause
them to deflect. When patients are instructed and directed to close
into the softened wax in CR it is also important to instruct them
not to bite through the wax, for if teeth touch they can deflect if
mobile, or if they are not mobile they can cause the path of closure
impressions are poured, the plaster teeth are not mobile, the plaster
teeth have no proprioceptors, and the articulator has no brain. So
once the casts are mounted and the articulator is manipulated, an
uncompromised picture of the occlusal conditions can be observed.
become state-of-the-science by orthodontists, it may reduce the amount
of orthodontics done by general practitioners because it will more
objectively show they may not be practicing to the standards of the
of casts is a discipline that leads to higher standards.
of casts is an educational and a reassuring experience for the orthodontist
as well as the patient. Patients learn before treatment is started
the importance you place on treating to centric relation, to functional
goals, and to health of the TMJ's.
respect and appreciate orthodontists that give high priority to occlusion.
casts are a better value for the orthodontist. They provide more information
for virtually the same amount of office time and cost.
Mounted casts lead to better diagnosis, better results, and to fewer retention problems.
interface in centric relation (CR) and when functioning can be seen
facially and lingually without having to deal with the patient's avoidance
CASTS MADE TO ABO STANDARDS
Take impressions and wax bite
Take impressions and wax bite
Rough trim to specified angles
Fill holes and fine trim plaster
Rough trim and mount casts
Fill and smooth the mounting plaster
out of 10
out of 10
Mounted casts take approximately the same total amount of operatory and
laboratory time to produce as do hand-held casts, but they provide better
COMPARISON OF HAND-HELD AND MOUNTED CASTS
After the initial investment of the articulator system
the materials cost of cast mounting exceeds that of hand-held casts
by the cost of the mounting plates and for the bitefork wax. Depending
on the system this cost can range from two to five dollars.
TRADITIONAL ARTICULATORS ARE IMPRACTICAL FOR MOST ORTHODONTIC PATIENTS
AND MOST ORTHODONTIC OFFICES
and Prosthodontists designed traditional articulators for their needs.
Orthodontists have adopted them because, until the Andrews™ Occlusofacial
Simulator™ Articulator System, there have been none designed by an
orthodontist for the specific needs of the orthodontist.
articulator systems recommend orienting the facebow to Frankfort.
This means the bitefork is also oriented to Frankfort. When the facebow
is transferred to the articulator, it is oriented to the articulator's
upper member, which is parallel to the articulator's transverse plane,
not to the articulator's Frankfort plane, because articulators have
no Frankfort plane. In the population the range for the angle between
the head's transverse plane and Frankfort is reported to be 30°. The
SI distance between those two planes at the front of the face can
be 50 mm. This means that the SI position of the front end of the
cast's occlusal plane can be 50 mm different on the articulator than
it is on the patient. The occlusal plane orientation to Frankfort
is satisfactory for those in dentistry that deal with dental reconstruction,
but not for those involved in improving the harmony of the entire
articulators are too costly for orthodontists to have one for each
patient. This means that one or several articulators are used for
all patients. An orthodontist may see 30 or more patients in an afternoon,
a gnathologist may only see a few. With only one or two articulators,
the orthodontist must remove and replace casts numerous times throughout
the day. This involves presumably adjusting the articulator to each
person's customized settings, retrieving the casts from a cabinet,
removal of rubber bands that hold casts together, screwing them on
the articulator, unscrewing them from the articulator, replacing the
rubber bands, and refiling each patient's casts. This is time-consuming
and involves extensive handling of casts-which is potentially hazardous
lingual perspective of the teeth is partly obstructed by the design
of most traditional articulators currently available.
articulators display only the posterior border goal for the dentition
(TMJ) because gnathologists do not deal with the other borders. Orthodontists
and surgeons do deal with all borders, and for them, it is very helpful
to have all border goals displayed.
If dropped, traditional metal articulators can be permanently damaged.
Traditional articulators are impractical for ABO presentations, because ABO Directors will not remove and place casts. For those that cast mount this means a minimum of three articulators is needed for each patient. That many articulators is cost prohibitive and difficult to borrow.
Traditional articulator systems are not designed to assist in AP diagnosis.
How to use the Simulator™ articulator can be learned from a manual, courses, by appointment in Dr. Andrews' office in San Diego, or by appointment in your office.