
FAQFrequently Asked Questions· From Dr. R. G. "Wick" Alexander: · FREQUENTLY ASKED QUESTIONS in orthodontics · As I travel around the world sharing my philosophy of
orthodontics to many audiences, I am always asked many questions concerning
the various subjects.Often these are noteworthy
questions whose answers should be in the text of the lecture. Since our web
site is read by hundreds of orthodontists around the world, I felt it would
be an interesting idea to create this column to share these questions and
answers with each other. It is my desire that you will not only read this
information, but also question me on subjects that are of interest to you.
One thing you can be for sure … if I know the answer, I will attempt to
explain it in such a manner that it will be easy to understand. If I do NOT
know the answer, I am very good at saying, “I don’t know.” · So what questions do you have about our technique … or orthodontics in general? I look forward to sharing my thoughts with you. F.A.Q. ·
Is
it possible to determine the most suitable age for starting an orthodontic
treatment and if it is, why? ·
Remember that there are exceptions
to every rule, but in general this is my advice. The most suitable age for
starting orthodontic is when all primary teeth have exfoliated, except the
primary mandibular second molars. Why? In many
borderline cases, utilizing the "E Space" will allow the case to be
treated nonextraction.This space of approximately 3
- 4 mm can be captured by placing a lingual arch and hold until the permanent
second bicuspids have erupted. If additional space is needed, a lip bumper
can gain another of 3 - 4 mm. ·
Which
malformations do you start treating early dentition and which do you monitor
until permanent dentition? ·
One of the most common mistakes we
make in orthodontics is starting treatment too early. Although it is
difficult to resist that initial down payment, in the long run, everyone will
be better off if treatment is delayed. Certain cases, however, should be
treated early. If delaying treatment will cause the malocclusion to
deteriorate, if it will get worse without treatment, early treatment is
desired. Such cases include anterior crossbites.
Posterior crossbites, unless severe, can be treated
later.Also, if an extreme overjet
is present, treatment is indicated to protect the teeth as well as possibly
improve the patient's self-esteem. Extracting primary mandibular
cupids prematurely is a BIG mistake ... unless you plan to extract permanent
teeth later. My advice is to not extract these teeth early. They are
"holding" the bone where the permanent cupids will erupt. ·
What
is the risk of relapse by an early orthodontic treatment? Should it then be
considered as an unsuccessful treatment? What should we clarify to the
parents of a young patient before we start the treatment? ·
The risk of relapse in early
treatment is very high. Asking a patient to wear retainers during this
interim period between fist and second phase is very difficult and time
consuming for patient and doctor. Parents should be aware that this early
phase is just the beginning. Final results will be not achieved until the
patient is approximately fourteen years old. Total cost is greater than
delaying treatment and treating only one phase, when permanent teeth have
erupted. "Timing is everything." As I reflect on my early treatment
history, there were many times when I should have delayed treatment but
instead ending up treating the patient for 5 to 6 years. Upon evaluation, I
could have achieved similar results by delaying treatment and treating in one
phase only. ·
How
do you analyze the causes of a relapse case, are you searching for your own
mistakes in the treatment plan; is it unfavorable skeletal growth; or is it
inadequate choise of appliance and treatment
approach? ·
Relapse: The eternal question ...
what causes orthodontic relapse? We
like to blame it on unfavorable growth, muscular habits, wisdom teeth, poor
cooperation, mesial drift.
Of course, each of these factors can have a negative influence on the
patient's stability. But the reality is that with most patients, if the
proper goals are achieved in treatment, the possibilities for stable results
are very real. The reason most cases relapse is that the teeth are placed in
unstable positions during treatment. ·
Should
the orthodontist be afraid when entering the room of truth, finding our
faults he had made in a treatment or should this help him expand his
knowledge? Do you think that mistakes, when analyzed, lead to the further
development of Orthodontics? ·
Do not be afraid of the "Room
of Truth." It should be just the opposite! With 10,000 sets of
diagnostic records to study, we are finding more and more evidence-based
knowledge that is telling the "truth." Often, we learn more from
our mistakes than from the excellent results. The door is always open to
anyone, regardless of their beliefs, to evaluate these cases. I want to
discover the truth, regardless of any particular technique or belief system. ·
What
reasons made you innovate the “Alexander System”? ·
This is almost a question regarding
my "purpose in life." :) The
Alexander Discipline has been evolving throughout my orthodontic career. My
early training in the ·
Would
you clarify the advantages of the “Alexander System” compared to the other
vestibular fixed techniques? ·
The Advantages of the Alexander
System: "Begin with the end in mind." To my knowledge, no technique
has had more research (over 50 studies) using the author's own cases to
demonstrate its long term results. If
used as instructed, this technique produces the most stable results in
orthodontics. But what makes it so nice is that achieving these results is
quite simple. All that is necessary is to "follow the rules. "These rules are specified in my new book,
"The 20 Principles of The Alexander Discipline," published by
Quintessence. Like everything in life, it does take discipline! For example,
you should learn how to bend omega loops and tie back the archwire
with a ligature tying pliers. Early in treatment, the flexible archwire with the additional interbracket
space will produce a very low friction force on the teeth. At the end of
treatment, the 17x25 ss archwire
in the .018 slot will produce high friction for proper torque control, tooth angulation and off-sets. If the Alexander brackets are
placed properly, beautiful results will routinely be achieved. In the near
future, I am hoping to design a self-ligation
bracket for our system. But rest assured that I will not sacrifice quality
for expedience. It will still produce the same results we are achieving now. Patient
compliance is critical. Motivating patients to achieve their goals is one of
the joys of my life. Not only does this improve the final results, but it is
a tremendous learning experience for the patient. Effort = Results. · Which recommendations would you pass on to the orthodontics so that they could obtain a steady and lasting treatment? · 1. Control lower intercanine
width · 2. Ideal mandibular incisor
position · Where
is the most stable positing? During years of my clinical observation,
“stable” is the position in which the patients presents. A stable range for mandibular incisors can be from 70 degrees to 110
degrees. Many orthodontists do not pay sufficient attention to torque control
of the mandibular incisors. When the mandibular incisors are indiscriminately tipped or
advanced, the doctor is creating a danger for potential relapse. The health
of the dentition and gingival tissue are also affected when the mandibular incisors are not positioned well. Some
orthodontists retract the teeth lingually. This
retraction creates an aesthetic problem with the facial profile resulting in
a dished appearance. · 3. Control flaring of lower incisors · The
flaring of lower incisors is prevented by – 5 degree lingual crown torque of
labial root torque in the lower incisor brackets. The initial rectangular archwire placed on the arch should be .17” x .25” D-Rect multi-stranded archwire or
.17” x .25” CuNiTi archwire
to give an appropriated torque on the lower anterior brackets. The effect of -5 degree torque, the rectangular initial wire and -6
degree angulation on the first molar are to
hold the mandibular incisors in their original
position. If the mandibular incisors are tipped lingually before treatment, a zero degree torque brackets
should be placed on the lower incisors. Anytime the doctor does not require
this negative torque, it can easily be deactivated using smaller rectangular
or round archwire. Another way to control flaring
of lower incisor is to make IER on the anterior teeth, mainly in the lower
incisors crowding cases. When the mandibular
incisors are tipped labially, the doctor can place
class 3 elastics to hold lower incisors. This should be addressed the day of
bracket placement. (Keep in mind vertical anchorage to maintain maxillary
posterior teeth in their position using Extra Oral Appliance(High
Pull), transpalatal bar and other appliances for
vertical control). · 4. Spread apart the roots of the lower anteriors · The
mandibular laterals should be positioned with more angulation(+6 degree) in order to improve stability.
Thus, the lower lateral roots will be aligned more parallel to the cuspid root, decreasing the rate of relapse. Clinical
observation of my post–treatment patients over the years had led me to agree
that one of the causes of relapse in the mandibular
anterior arch has been the poor artistic positioning of the mandibular lateral incisors. · 5. Good interincisal angle · An
ideal interincisal angle must be established during
treatment by controlling torque on the mandibular
and maxillary incisors. · 6. Upright lower 1st molars · The
long-term stability of deep bite cases is also related to the ability to
upright, or tip back, the mandibular first molars
achieved by placing an angulation of -6 degree on
the 1st molars. By uprighting the first molars, the
anterior arch length is increased, the second premolars are simultaneously
extruded to help level the mandibular arch, and the
posterior occlusal stops are established to prevent
anterior overbite relapse. · 7. Obtain good buccal
occlusion by sectioning posterior archwires and
using finishing elastics. · 8. Retain until through growth due to remanescent cranial base growth · 9. Enamel reduction of lower anteriors
after removal of 3 x 3 · This
procedure allows for future anterior and lingual migration of the cuspids without concurrent mandibular
anterior recrowding. Furthermore, slenderizing
remodels the mandibular anterior interporximal contact points into contact surfaces. This
situation helps to maintain mandibular anterior
alignment. · 10. Musculature · The
question is “Can muscle pressure influence tooth position?” Many studies( ) have been shown that tooth stability are
directly influenced by muscle balance existed between the tongue on the inner
side of the dental arches and the muscles surrounding the outer side of the
dental arches. Muscle function must be regarded as a dominant factor to keep
tooth in their balanced position. Muscular habits, such as tight lip
musculature, placid lip musculature, mouth breathing, tongue thrusting, and
sucking habits(thumb sucking lip biting, nail
biting) can place abnormal forces upon the dentition to cause significant
relapse. This is the reason to eliminate these habits as early as possible in
treatment. · 11. Overcorrection of rotation & Circumferential Supracrestal Fiberotomy · After
correction, a severely rotated tooth has a tendency to return to their
original position due to the memory of transeptal
fibers. These fibers are stretched during treatment and after appliances are
removed, the fibers tend to contract returning the teeth toward to their
original position. Post-treatment and post-retention relapse are minimized in
adolescent patients with crowded pretreatment conditions, holding their teeth
with retainers after treatment. The fibers seem to reshape to a new dental
configuration easily. However, when maxillary laterals are positioned lingually prior to treatment, a significant tendency for
relapse remains. Another case include a severe
rotated teeth and previously impacted teeth. In adult patients a
reconfiguration of the transseptal fibers is slow
compared to adolescent patients during active treatment and retention. For
this reason the circumferential supracrestal fiberotomy is a routine procedure. This surgery is
preformed six weeks prior to appliance removal. Thus, the transseptal
fiber memory is reduced, preventing significant relapse. Circumferential Supracrestal Fiberotomy should
be done after correction of any preorthodontically
rotated teeth, especially maxillary and mandibular
anterior teeth. The procedure should be done before debonding
after mild(3 degree to 5 degree) overcorrection. · 12. PRAY! · Considering your professional way of acting clinically, which duties do you consider of importance besides the diagnosis and treatment plan and which ones would you delegate to the auxiliary staff? · One
of the most appealing things about orthodontics is the ability to DELEGATE.
The problem occurs when this opportunity is abused. In general, my thinking
has always been to delegate anything that I can train a staff member to do as
well or better than I can do. · This
includes removing the archwire and bending omega
loops in the new wire, then ligating the archwire into the patient’s brackets after the doctor has
checked it. BUT the doctor must be in charge! Bracket placement and cementing
orthodontic bands is critical and should not be delegated. Developing the
arch form, placing curve, etc., can only be accomplished by the doctor. · After
the doctor has adjusted the facebow, the assistant
can instruct the patient on the placement of the facebow,
elastics, and strap. · Oral
hygiene education is the job of everyone on the staff. · The
key is to find a person who has “good hands” and enjoy working with people,
then train them properly before they begin to work on patients. Then
supervise them closely until you are confident in their ability. A well
trained staff is a key component to a successful orthodontic practice, but it
is like all other things ins life… it takes EFFORT! · What would your advice be to the young orthodontist in the beginning of their careers, in the sense of achieving a good clinical level and credit on their clinical function? · Have
priorities in your life. What are really the most important things in your
life? Health, family, religion, profession. · Learn
the fundamental of orthodontics …understand functional occlusion and the
MECHANICS of bending wire to produce torque, tip, offsets, up & down. How
to correct skeletal discrepancies in growing patients. · Understand growth and development so that you can DIAGNOSIS the
problem accurately. · TREATMENT PLANNING – know what works to achieve your goals and
how to reach them. · Learn
the GOALS for long term stability and strive to achieve them in every case. · The
last 6 months of treatment is the most critical. Learn how to FINISH the
case! · Learn
how to MOTIVATE the patient to follow your instructions. The orthodontist is
only as good as his/her patient. · Don’t
be misled by the promoters who say things that sound too good to be true…
because they are. · In
summery, apply the knowledge you have acquired, go slowly, study your own
results and find what works vest for you. And always remember to treat each
patient as if they were your own child! · Which recommendations would you pass onto the orthodontists so that they could obtain a steady and lasting treatment? · STABILITY · Obtain a good buccal occlusion · In
my technique, certain procedures are essential to create an ideal buccal occlusion at the end of treatment. The final
detailing and settling in the posterior and anterior area is carried out by
sectioning the archwire and wearing up-and-down
finishing elastics. The maxillary and mandibular
arch is sectioned usually between the cuspids and
first bicuspids depending on the individual case. After sectioning, the archwire is removed posterior to the cuspids
on both sides of the arch in order to leave these teeth free to move
vertically. The anterior sections remain in the arch allowing correction of remanescent torque control and rotations. Zig-zag elastics are wearing depending on the case. · If
the original malocclusion was a Class II deep bite case, the lower arch only
is sectioned. The archwire is bent distal to the cuspids. A ¾ inch, 2 ounces round elastic I attached in
each posterior segment. In a Class II case, these up-and-down elastics are
attached on the maxillary lateral incisor(extraction
case), or the maxillary cuspids(non-extraction) and
continues through the second maxillary and mandibular
bicuspids creating a “W with tail” elastic configuration. The posterior
up-and-down elastics will deliver an extrusive force to the mandibular bicuspids and molars area in order to help
improve or maintain a level lower arch. It is important to understand that
most of deep bite cases demonstrated a severe curve of Spee.
· Consequently, the bite will be stabilized so that the overbite will
be less likely to relapse after treatment. This design creates a Class II
vector in order to close down the buccal segments.
The up-and-down elastics should be wearing for two weeks before sectioning
the upper archwire. The elastics should be worn for
two weeks and the appliance can be removed. · In an open bite or Class III tendency, the upper archwire is first sectioned. Some curve of Spee have been placed in the lower and upper arch. The up-and-down elastics are worn in the “M with a tail” design creating a Class III vector. The up-and-down elastics are attached on the mandibular canine, continue through maxillary canine until upper second bicuspid and worn for two weeks. The same procedure is carried out as observed for Class II cases. In a Class I case, both arches may be sectioned and the patient wears an “M with a tail” or “W without a tail” depending upon the need. The doctors will decide which posterior segment should be extruded before sectioning the archwire. The anterior overbite/overjet relationship is corrected wearing anterior up-and-down elastics with a Class II or a Class III vector, or anterior box elastics. · Why use Single Brackets rather than Twins? · In
orthodontics, the amount of force placed upon the teeth will affect the
movement of these teeth. Teeth will move in three dimensions … 1) Labio-lingually, 2) Inciso-gingivally,
and 3) Mesio-distally. The challenge is to move the
teeth into their desired positions in a direct path with the smallest amount
of force possible. · The
first decision is to determine where the teeth should be at the end of
treatment …your treatment goals. Then proper mechanics should be employed to
gently move those teeth into these predetermined positions. · In
a “fixed” appliance, teeth can be moved by first placing brackets on the
teeth, then inserting an archwire into these
bracket slots. The archwire will deliver the forces
to move the teeth. So, the amount of movement and direction of movement of
the teeth is determined by the bracket design and the archwires
used. · Another factor that may have a limited effect upon the tooth
movement could be the intraoral muscular forces. It
is well known that orthodontic forces can overpower the muscular forces
during treatment; however, after treatment and retention, the muscles will
move the teeth back to their balanced positions. · The Value of Interbracket Space · What is the difference in using twin brackets and single brackets? · Basically, it is the difference in the amount of space between the brackets. This is called interbracket space. Why is this important? · Does it really make any difference if the space between brackets is greater or less? · Clinically, I routinely see that early in treatment the teeth align themselves very quickly with little discomfort to the patient. · Is this a result of interbracket space? If so, why? · Mechanical engineers will tell you that the rate between the load (Force) and application distance (d) is inversely proportional to the 3rd power of the distance (1/d)³. If the other variables remain constant (wire stiffness, length, elasticity modulus), when the distance between brackets is increased two times, the force applied would decrease EIGHT times. F= (1/d) ³ = (1/2) ³ = 1/8 “Load /Deflection rate of any wire is directly proportional to the diameter of the wire and inversely proportional to the third power of the length of the spring (longer wire = less stiffness to the 3rd power)” – Dr. Marcotte Clinically, this means that by using the same archwire on two patients, one using twin brackets and the other using single brackets, doubling the interbracket space, the amount of force placed on the teeth could be eight times less on the single bracket patients. This less force reduces undermining resorption and discomfort to the patient. The other advantages include: this archwire is more simple to engage and ligate; and/or a larger archwire could be placed with no more discomfort to the patient. · WHAT ABOUT TORQUE? · This
increased space also allows for additional torsion control because a larger
rectangular archwire can be engaged with no more
force. The flexibility allows for fewer archwire
changes – getting into finishing archwires sooner.
Torsion allows earlier placement of rectangular archwires
for faster torque control. · Advantages of Interbracket Space: · This additional space gives the archwire more resiliency and flexibility and will deliver a lighter force. When activated, the archwire is “alive.” There is less force applied to the teeth with the initial archwire due to the increased flexibility of the archwire allowed by the interbracket space. Energy is stored in this bent archwire and dispersed gradually over a longer period of time. Patient discomfort is then reduced. · INTRA-BRACKET SPACE · A.Inciso-gingival dimension: · Another issue to discuss is “intra” bracket space. This is the
space between the bracket slot and the engaged archwire.
In a round archwire, the dimension of the wire will
have an effect on the “friction” created while sliding through the slot. The
smaller the wire, the less friction will be present: therefore, the more
tooth movement will take place. · It is well known that for every .001 inch of space, 5degrees of torque is lost when using a rectangular archwire. This is assuming that the quality of the bracket and archwire manufactured is of high quality. When the objective is to control the torque of the teeth, then a greater amount of “friction” is required. This is accomplished by filling up the slot with a larger rectangular archwire. This prescription gives just the right amount of freedom. · B. Mesio-
distal dimension: · Some believe that a wider bracket is needed to control root angulation. In the Alexander Discipline this is not necessarily. Observe the panoramic radiographs in any of our finished cases in the lower anterior area and the only poor angulations you will find is the result of poor bracket placement! · Mechanics · The
philosophy of AD is “control” … when needed. Do we need less friction or more
friction? We can choose to have less friction or more friction not only in
the archwire selected but within the arch itself.
By choosing the type of ligation, friction can be
controlled within the same archwire. How is this
accomplished? When the archwire is engaged into the
bracket slot, the forces then come alive and begin to move the teeth. Because
of the flexibility of the archwire (new space age
materials and increased interbracket spaces), the
key is to “let it cook.” This has been one of our principles for many years!
This is especially true in the maxillary archwire.
The size of the archwire being placed into the
bracket slot is the key to the amount of freedom and/or control. NiTi .014 or .016 wires are common initial archwires. · The
design of the ligation can influence the amount of
friction on the archwire. The figure 8 ligation tie can reduce the friction. Steel ligation has less friction than elastomer
rings. · In the mandibular arch, a rectangular archwire will give a controlled, limited amount of tooth movement. This is because in most nonextraction cases the goal is to control the incisor torque as soon as possible. A flexible rectangular archwire is then often the wire of choice … CuNiTi or DRect. · Curve of Spee · When placing reverse curve into the mandibular archwire, the wire needs to be able to “slide” through the bracket as the teeth are leveled. Twin brackets will bind the wire much more than a single bracket because of the increased mesio-distal distance of these brackets. A simple test can demonstrate this fact. Compare how a typodont tooth will slide on an archwire using a twin bracket versus a single bracket. Add curve into the wire and the effect is even greater. The single bracket will slide much easier. · Archwire Sequences / Retainer Effect · The goal of sequencing archwires is to “get into the finishing archwire quickly, and let it cook.” (Principle # 13) This is accomplished within the first six months in most cases. As a result, the final archwire moves the teeth into their ideal positions, and then a “retainer effect” takes place. The archwire holds the teeth in their final positions for the remainder of treatment. As a result, after appliances are removed, the retainer is worn at night only. This can only have a positive effect on long term stability. · Send in any questions you may have about The Alexander Discipline to ejesj22@yahoo.com |