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MBT PHILOSOPHY OF ORTHODONTIC TREATMENT - A PERSONAL INTERVIEW
| Dr. Richard McLaughlin completed his orthodontic training at the University of Southern California in 1976. Since then he has been in the full time practice of orthodontics in San Diego, California. While developing his own practice, he was an associate of Dr. Lawrence F. Andrews for seven years. Dr. McLaughlin has lectured extensively on the pre-adjusted appliance in the United States, Europe, South America, Asia and Australia with orthodontic colleagues from London, England, Dr. John Bennett, and from Sao Paulo, Brazil, Dr. Hugo Trevisi. He is a member of the Pacific Coast Society of Orthodontists, the American Association of Orthodontists, a Diplomate of the American Board of Orthodontics, and a full member of the Edward H. Angle Society. In addition, Dr. McLaughlin is an associate clinical professor at the University of Southern California, Department of Orthodontics. |  |
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Dr. Masatada Koga is a graduate of Tokyo Dental Univeristy in 1970. He also completed his post-graduate work there. Since 1979, he has been assistant professor at the university. He is a member of the Edward H. Angle Society. |
1. Dr. Andrews developed the original SWA and formed the basis of the straight wire system through an epoch-making advancement of Edgewise technique, followed by Dr. Roth's contribution to a further development of this system. What was your main concept that you had in mind in developing the MBT system as the 3rd generation straight wire system?
After describing standardized goals of static and functional occlusion, Drs. Andrews and Roth developed their own straight wire appliance systems based on the mechanics that they used to achieve their goals. All of us in orthodontics are indebted to Drs. Andrews and Roth for providing us with these goals, which have truly stood the test of time. When Drs. Bennett, Trevisi and I began using the various straight wire systems, our goal was to determine if a more efficient system of mechanics could be developed with the preadjusted appliance. Our combined clinical observation was that when we began using lighter forces than we were accustomed to with the Edgewise appliance, some of the compensations that had been built into the straight wire system were not necessary with these force levels. We returned to the use of the original straight wire appliance system, began using light force mechanics, and began evaluating the preadjusted appliance according to the six stages of treatment. We determined that very few adjustments needed to be made from Andrews' original non-orthodontic normal measurements concerning tip and in-out compensation. However, the weakness of the preadjusted appliance was determined to be in the area of torque control and a number of very important compensations needed to be made in that dimension. These principles form the basis of the MBT Appliance System, which you have appropriately termed the 3rd generation straight wire system.
2. Next, I have questions on each of the four components of the MBT System:
A. Treatment Mechanics
B. The MBT Appliance
C. Arch Form and Archwire Sequencing, and
D. Bracket Placement.
A. Treatment Mechanics
1) Treatment mechanics has direct impact on treatment results in orthodontic treatment. Which maxillo-facial structures can be modified with orthodontic treatment? Can we produce orthopaedic changes? Are these questions important when we consider treatment mechanics?
There are two clinical observations that we have made relative to orthodontic treatment mechanics. First, the majority of change in orthodontics appears to be dento-alveolar in nature. While there may be some orthopaedic changes going on, these changes are obviously somewhat subtle in nature since no one has been able to conclusively demonstrate that such changes consistently occur. Rather than assuming that all those who have studied this over the years have some how failed to capture the nature of this orthopaedic change, it is more logical to assume that very little orthopaedic change does occur. In this regard, we can therefore focus our attention on directing appropriate forces at the dental structures that we are trying to move. Secondly, continuous forces appear to be far more efficient when it comes to orthodontic tooth movement than do intermittent forces. When we put these two clinical observations together, we are provided with a definite direction concerning treatment mechanics. That is, the most effective way to carry out orthodontic treatment is to try to place light continuous forces on those dental units that we are trying to correct, and, at the same time, take advantage of the inefficiency of intermittent forces placed on those dental units that we do not wish to move.
2) Some Japanese orthodontists claim that heavy forces are generated with .022 slot brackets. They say "It's anachronistic to use these brackets in the .018 Edgewise era". I believe .022 slot brackets are more effective in a preadjusted system. What is your view on .022 preadjusted appliances and the orthodontic forces used with these appliances?
First of all, it is important to remember that the forces generated by archwires are determined by two factors: 1) wire size and 2) wire deflection. Given the same amount of deflection, obviously a larger archwire will generate a greater force. However, given the wide variety of archwire sizes that are available today, as well as the tremendous ranges in archwire flexibility and archwire stiffness, there is no reason that orthodontists using either the .018 or .022 should be generating excessive forces. If this is occurring, it is certainly more operator related than it is related to bracket slot size! Therefore, during the stages of levelling and aligning and overbite control, there should be relatively little difference between the two slot sizes if appropriate archwires are used. One of the real advantages of the preadjusted system is the ability to use sliding mechanics during the stage of space closure. Sliding mechanics cannot occur effectively if there is archwire deflection. It is our position, therefore, that because we can use a heavier and stiffer wire during space closure, there will be less deflection (this does not in any way imply that a greater force is being applied). Hence, the .022 slot does have an advantage over the .018 slot during this most important stage. Each case should be properly levelled and aligned so that when these heavier rectangular wires are placed, there is minimal deflection and hence a lack of heavy forces.
3) There has been a criticism that the SWA burns anchorage. Please give me your thoughts on anchorage control?
Andrews pointed out a number of years ago that many Edgewise cases were 20% under-treated. He further stated that if one is going to move teeth from one position to another, the same overall amount of energy is required no matter what bracket system or technique is used. We agree with this position. However, the energy needs at the various stages of treatment are different with the preadjusted appliance. There are two critical periods of anchorage with the preadjusted system. First, during the levelling and aligning stage when tip is being expressed. With the Edgewise appliance this tip was introduced more gradually and hence spread out over a greater period of time. With the preadjusted appliance this anchorage need occurs with the placement of the first archwire because of the tip built into the brackets (figure 1). The second critical time for anchorage control is during the stages of space closure and overjet reduction when torque control becomes such an important factor. If we are to achieve this additional 20% of correction concerning tip and torque control, then we must manage our anchorage carefully with the preadjusted appliance, especially during those two critical stages of treatment.
Figure 1 Effect of initial archwires on anterior teeth with the preadjusted appliance
4) What are the important points that we should pay attention to during levelling and aligning? Please explain the significance of lace-backs in particular.
During the stage of levelling and aligning it is our belief that it is important to avoid excessive tipping of the teeth, which eventually leads to an overall extrusive effect on the dentition. Very critical teeth in this regard (especially with extraction cases) are the upper and lower cuspids. It has been our experience that the most effective way to move cuspids distally without excessive tipping is to use a simple figure eight ligature wire (which we call a lace-back) rather than an elastic chain (figure 2). The figure eight ligature wire initially tips the tooth very slightly. However, when the archwire is then placed there is a gentle continuous force over a four to six week period of time which allows the root to catch up and therefore re-upright the tooth. When an elastic chain is used the tipping force continues and there is inadequate time for the roots to catch-up. Hence the tipping tends to continue. This is the most important aspect of levelling and aligning with the MBT technique.
Figure 2 Illustration of lacebacks used to control cuspids during extraction treatment
5) What are the important things that we should keep in mind in controlling overbite?
Overbite control (and here we are referring to the deep overbite) goes hand in hand with the concept of levelling. We believe that it is important from the beginning of the case to avoid tipping of teeth which causes extrusion and in particular anterior bite deepening. Hence, the main principle of overbite control is to avoid excessive tipping of teeth. Other very important factors related to overbite control are the use of bite plates and most importantly the early banding of the second molars. Cases that are level from first molar to first molar will still show a deep overbite. It is the important inclusion of the second molars in the archwire system that allows for final levelling of the curve of Spee and opening of the deep bite.
6) Many Japanese orthodontic patients seem to require extraction treatment, making space closing mechanics particularly important for us. I have several questions on space closing mechanics.
a) Which is more advantageous or effective with a preadjusted system, sliding mechanics or closing loop mechanics?
Closing loop mechanics can certainly be an effective method of space closure with the preadjusted appliance. However, it is more time consuming to construct closing loops on all of our patients. Secondly, the break in the archwire where the loop is positioned causes a flexibility in that area which can lead to collapse of the arch form in that area and bite deepening. For this reason, additional second order compensation must be placed either in the brackets or in the archwire. This requires either additional bracket inventory or additional wire bending time. Therefore, sliding mechanics, when used properly without excessive archwire deflection, can be very effective and also advantageous in terms of saving time.
b) Do unbent, straight wires suffice for sliding mechanics? Or does wire bending raise the efficiency of sliding mechanics? If so, why?
It is our belief that the most effective way to slide an archwire through the posterior brackets is to have the archwire completely flat as opposed to having compensating curves placed in the archwire. These curves cause friction and hence reduce the efficiency of sliding mechanics. It is often recommended that some compensating torque be placed in the incisor area of the archwires during sliding mechanics. This helps to keep the incisors at the proper inclination during space closure.
c) What size of main archwires do you use for space closure with .022 slot preadjusted brackets?
We have tried various sizes of wires for our sliding mechanics with an .022 slot. The .021 x .025 wire, while showing minimal deflection, does create excessive friction and therefore is not as effective for sliding through the posterior brackets. The .018 x .025 wire, on the other hand, has been shown to deflect more easily, creating friction in the system. Hence, we have chosen to use the middle size wire which is the .019 x .025 wire in the .022 slot. This wire size has demonstrated the best balance between minimal deflection and ability to slide through the posterior brackets.
d) Many orthodontists in Japan use .018 slot preadjusted brackets. Which is more effective .018 or .022?
As I previously stated, the levelling and aligning and overbite control stages of treatment can be accomplished nicely with either slot system. However, it is our belief that during the critical stage of space closure and sliding mechanics, a slightly heavier wire will show less deflection without actually creating an additional amount of force. If anything, less force is applied because of lack of deflection! Hence, we believe that the .022 slot is the preferred slot size for the preadjusted appliance system primarily because of its advantage during sliding mechanics. Other differences between the two slot systems are actually quite minimal and rather insignificant because of the advanced technology in archwires.
7) Please explain your finishing system:
Our finishing system emphasizes two main points. First, is the attention that must be played to over-correction and potential relapse problems, and, second, is the need to allow cases to settle in light wires prior to the placement of retainers. Let's briefly review these two areas. First, during finishing it is important to evaluate potential relapse problems and hence the areas where over-correction is needed. These areas are the following:
a) Periodontal - this is primarily related to rotation control and
avoiding excessive last minute extrusion of teeth.
b) Osseous - this relates to avoiding the excessive over-expansion of arches
against the cortical plates (which ultimately leads to relapse) and the
management of sutural relapse after maxillary expansion. Over expansion
is often needed
c) Muscular - this relates primarily to controlling tongue habits, mentalis
habits and buccinator muscle problems.
d) Growth - this is the most difficult area to deal with because growth
after orthodontic treatment can be very unpredictable. Cases can be slightly
over-corrected based on anticipated growth changes.
The second major aspect of finishing is related to allowing cases to settle at the end of treatment so that there is a more natural adjustment of the dentition relative to the muscle physiology of the patient.
8) What is your concept of retention?
At this time we generally prefer to use lower bonded retainers. A .019 multi-strand wire is placed behind the lower anterior teeth (and into the mesial fossa of the bicuspids in extraction cases) and secured with a strong adhesive to each of the anterior teeth. In the upper arch a wrap around retainer is utilized, which allows the upper teeth to settle into the lower dentition without wires bridging across the occlusion.
9) Please explain about the types and sequence of archwires used for levelling and aligning, sliding mechanics, bite opening and finishing.
The figures (figures 3 and 4) below shows the six traditional steel wires that are used in the sequence of levelling and aligning and some of the new heat-activated wires that can be substituted for these steel wires.
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Nitinol Heat-Activated .016" |
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Nitinol Heat-Activated .019 x .025 |
These substitutions have three main advantages:
a) They reduce the amount of chair time, because instead of changing
wires each visit we are often simply retying wires.
b) Patients can be seen less frequently because the wires continue to work
effectively over a longer period of time.
c) The new heat-activated wires actually move teeth more effectively than
do stainless steel wires.
Therefore, these substitutions have a very profound effect on the efficiency of an orthodontic practice. It must be pointed out, however, that these wires are flexible and are good for aligning procedures only. They are not effective for the final stage of levelling, for final bite opening and for overjet reduction or space closure. The working .019 x .025 rectangular stainless steel wires are preferred during these stages. And finally, during the finishing stage, using very light wires such as a .016 heat-activated wire in the lower arch and a .014 sectional wire in the upper anterior segment allows the case to settle into a final position quite nicely in most cases.
B. THE MBT APPLIANCE
1. I understand the measurements adopted for the MBT Appliance are on several studies including the Andrews' original study and the Japanese studies by Sebata, Watanabe and Koga. How did you use these basic research data in designing the MBT Appliance in terms of its prescription?
The tip measurements and most importantly, the anterior tip measurements in the MBT system are based on the original Andrews study, as well as those of Sebata, Watanabe and Koga (table 1).
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Upper Anterior Tip |
Lower Anterior Tip |
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Central |
Lateral |
Cuspid |
Central |
Lateral |
Cuspid |
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| Andrew's norms |
3.59 |
8.04 |
8.4 |
0.53 |
0.38 |
2.5 |
| Sebata's data |
4.25 |
7.74 |
7.7 |
-0.48 |
-1.2 |
1.5 |
| Watanabe's data |
3.11 |
3.99 |
7.7 |
1.98 |
2.28 |
5.4 |
| MBT Versatile |
4.0 |
8.0 |
8.0 |
0 |
0 |
3.0 |
| Original SWA |
5.0 |
9.0 |
11.0 |
2.0 |
2.0 |
5.0 |
| Roth SWA |
5.0 |
9.0 |
13.0 |
2.0 |
2.0 |
7.0 |
Because tip appears to be the strength of the preadjusted appliance and because with light forces there is no need for second order compensation with our mechanics, it was determined that the original Andrews anterior tip figures, supported by those of the other studies, were the most ideal tip measurements for the MBT Appliance. Secondly, the in/out measurements of these studies were quite satisfactory and for the most part, were used in the MBT Appliance. The only modification that was made in the in/out dimension was the addition of 0.5 of in/out in the upper second bicuspid bracket. This is recommended for those cases with smaller upper second bicuspids relative to the upper first bicuspids (figure 5).
Figure 5. An upper second bicuspid bracket with an additional .5 mm of in-out compensation is provided for the common situation in which upper second bicuspids are smaller than upper first bicuspids.
The torque measurements carried out in these studies were reviewed; however, because torque is the weak link in the preadjusted appliance, torque modifications were needed in the MBT Appliance and these modifications are described below.
2. Upper and lower anterior tip is reduced for the MBT Appliance. Why?
As I stated above, upper and lower anterior tip was reduced in the MBT Appliance to correspond with the studies of Andrews, Sebata, Watanabe and Koga. Tip compensation is not needed with the light force mechanics that we are using. This change has dramatically reduced the anchorage needs of our cases. By using additional tip in the anterior brackets, anywhere from 2 to 3 mm of molar anchorage can be lost in bringing the roots of the anterior teeth to this over-angulated position. We have eliminated that anchorage need without compromising any aspects of static or functional occlusion (figures 6 and 7).
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3. The MBT Appliance has O° upper posterior molar tip to achieve 5° of effective tip on the upper molars. What do you mean by "effective tip"?
According to Andrews study, the buccal groove of the upper first and second molar lies 5° off a line drawn perpendicular to the occlusal plane. This is what is meant when one says that the upper first and second molars have 5° of tip. We agree with this tip measurement. This 5° of "effective tip" can be achieved in two ways.
The first way is by placing a 5° tip bracket with the bracket wings parallel to the buccal groove. This means that the band and bracket must be seated more gingivally on the mesial aspect to achieve the effective 5° of tip (figure 8a). If a band with a 5° bracket is placed parallel to the occlusal surface of the molar, then an effective 10° of tip is expressed (figure 8b). This, of course is excessive. The second way to achieve 5° of effective tip (the choice we made) is to place the band with a 0° bracket parallel to the occlusal plane, which then will place the buccal groove in its correct 5° position (figure 8c). This was done because the band is designed to fit in a parallel manner on the first and second molars.
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4. How did you decide tip measurements for the lower molars? Andrews' and Roth's measurements are +2 and -1°, respectively.
The buccal groove measurement for the lower molars was determined in a manner similar to that for the upper molars. The buccal groove on the lower molars lies 2° off the perpendicular to the occlusal plane. Therefore, with the MBT Appliance the same principal was used for lower molar brackets. 0° of tip was placed in the lower molar brackets, and these brackets and bands are placed parallel to the occlusal plane, providing an effective 2° of tip in the lower molars. Andrews' measurement of 2° represents the same tip in his study, and Roth -0° provides 3° of uprighting or "tip back" in the lower molars. It is our belief once again that second order compensation is not needed with light force mechanics.
5. Why was palatal root torque increased for the upper incisors in the MBT system?
The most common torque need for the upper incisors during orthodontic treatment is increased palatal root torque. This torque tends to be lost during the stages of overjet reduction and space closure. Therefore, an additional 10° of palatal root torque was added to the upper central incisors (to +17°) and an additional 7° of palatal root torque was added to the upper lateral incisors (+10°) (figure 9a and b).
6. Why was lower anterior labial root torque increased in the MBT system?
Once again, the most common torque need for the lower incisors is labial root torque to bring them into a more upright position. This is because they tend to be inclined labially due to elimination of crowding, leveling of the curve of Spee, and the use of Class II mechanics elastics. Hence, an additional 5° of labial root torque was added to the lower incisors, providing them with -6° of torque (figure 9c).
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7. How did you decide about upper molar torque for the MBT Appliance?
The most common torque need in the upper molars is the need for additional buccal root torque. This buccal root torque tends to be lost with expansion procedures in the upper arch. When this buccal root torque is lost, there are frequently interferences between the palatal cusps of the upper molars and the lower molars. As Dr. Roth did a number of years ago to aid in the correction of this problem, an additional 5° of buccal root torque was added to the upper molars, providing them with -14° of buccal root torque (figure 10).
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8. How did you decide about lower molar torque for the MBT Appliance?
The most common torque need for the lower molars is buccal uprighting. Frequently these molars tend to roll in lingually, as a result of treatment mechanics and in particular, the position of the lower second molar in the developing ramus. Therefore, progressive buccal crown torque was added to the entire lower posterior segment with a 10° reduction of torque for the lower first molars, bringing it to -20°, and a full 25° reduction of torque for the lower second molars, bringing them to -10° of torque (figure 11a and b).
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C. ARCH FORM
1. You have proposed 3 different arch forms. What are the reasons for your decision on the 3 arch forms? Some orthodontists use only one arch form in 3 different sizes: small, medium and large.
While there have been attempts to find the perfect arch form for all patients, research indicates that there is a great deal of variation in human arch form. Therefore, the use of a single arch form in three different sizes does not take into account for this variation in human arch form. It was felt that a system was needed for selecting the most ideal performed arch form for each patient, followed by some minor customizing. This system we selected was based on an evaluation of the four parts of the arch form as follows:
1. The anterior curvature - This curvature is based primarily on inter-cuspid width, with its shape being more tapered when inter-cuspid width is narrow and more flattened or square when the inter-cuspid width is wide. Archforms have been generally classified as tapered, ovoid and square based primarily on the anterior curvature. Superimposition of these arch forms is shown in figure 12.
Figure 12.
2. Inter-cuspid width - This seems to be a very critical factor in arch form, since research indicates that when inter-cuspid width is increased, there is approximately a 70% chance of relapse to the original inter-cuspid width. The average range of inter-cuspid width is approximately 6 mm and if an arch form system can provide this range, then it is suitable for the orthodontic practice.
3. Posterior curvature - The posterior shape of the dental arch has been described in the literature as a straight line (the Bonwill-Hawley arch form) and a rather dramatic curvature (the Brader arch form). It is our belief that the bicuspids can be slightly wider than the inter-cuspid width to provide better function during protrusive movement as Roth has described. Therefore, we have decided upon a very gentle curvature from the cuspid back to the second molar with the bicuspids being slightly wider than the cuspids.
4. Inter-molar width - There is obviously a great deal of variation in inter-molar width from patient to patient. However, it is impractical for manufacturers to make a significant number of arch forms with varying intermolar widths, because the process of making pre-formed arches is quite expensive. Therefore, we have selected arch forms that are the same width in the molar area (figure 12), and we suggest that the inter-molar width be adjusted in the arch form prior to placement of the archwires. This minor adjustment is quite easy, as opposed to adjustments made from cuspid to cuspid in the arch form. For this reason we have selected three arch forms (tapered, ovoid and square) that provide approximately a 6 mm range of inter-cuspid width for selection in the treatment of our patients. We then suggest that the posterior part of the arch form be adjusted to correspond to the proper inter-molar width.
2. What criteria should we use in selecting a proper arch form for each patient?
Our system calls for the use of three clear templates that can be placed over the lower study model, allowing us to select the arch form with the proper inter-cuspid width and anterior curvature.
D. BRACKET PLACEMENT
1. Please talk about how you have come up with the idea of using a bracket placement chart and preadjusted Dougherty gauges?
In general, placing the bracket in the center of the clinical crown is an idea described by Andrews. It is our belief that this concept is correct if orthodontists are going to accept average measurements made on ideal occlusions and then place brackets in the position where the measurements were made. However, there are numerous difficulties in finding the center of the clinical crown. These include:
Thus, having a more accurate method of locating the center of the clinical crown was felt to be necessary. This was accomplished by developing a bracket placement chart. Studies were done to establish the average distance from the incisal or occlusal surface of the tooth to the center of the clinical crown. These average figures were placed in the middle row of a chart for the upper and lower arches. Increments of 1/2 mm and 1 mm were added above and below these average rows on the chart (figure 13). This provided a method of selecting the most appropriate row for the upper and lower arches, and then placing brackets with gauges at these distances.
Figure 13 The MBT bracket placement chart
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2. Please explain how to use the Dougherty gauges?
The Dougherty gauges (figure 14)are used by placing the long extension of the gauge on the incisor or occlusal edge of the tooth, and then using the shorter extension to determine the position of the bracket slot. Because the bracket is covering center point of the clinical crown, the shorter part of the Dougherty gauge cannot actually reach this point of the tooth. Thus, there is an angulation concern as this part of the gauge comes in contact with the bracket. For this reason the Dougherty gauges are used by placing them parallel to the anticipated occlusal plane. This method is used on the cuspids and all the posterior teeth. Because of the great deal of variation in incisor angulation, when using the gauges with the incisors we recommend that they be placed perpendicular to the tooth surface. Because the torque measurement for the lower incisors is -1°, this method actually places the gauges parallel to the anticipated occlusal plane. Because the upper incisors have positive torque, the brackets will be positioned slightly gingival when the gauge is placed perpendicular to the tooth's surface. This is a positive factor which provides just a slight increase in the amount of overbite.
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3. Please explain briefly your basic concept on mixed dentition treatment and appliances used.
In general, if treatment can be effectively carried out with a single phase, then this is recommended as opposed to mixed dentition treatment. However, there are certain clinical situations in which mixed dentition treatment greatly aids in the overall success of the case. This includes the following areas:
It is our belief that most anterior and posterior crossbites should be corrected in the mixed dentition phase, that severe crowding can be alleviated by the extraction of deciduous teeth, and in particular the deciduous cuspids, that when deciduous teeth are lost prematurely space maintenance should be considered, and that when skeletal problem are moderate to severe they can and should be corrected early.
Concerning skeletal correction, a combination of expansion when needed, fixed (2 X 4 appliances) to align teeth and advance upper incisors, and functional appliances to encourage early dental alveolar change are appropriate in the mixed dentition. While the authors have used various forms of fixed and removable functional appliances over the years, at this time the Twin Block appliance is the appliance of choice for the correction of most Class II skeletal problems.
4) Please explain briefly how you would treat orthodontic patients with TMD.
It is important to allow for stabilization and healing of patients with TMD prior to orthodontic treatment. The first phase of this process is carried out utilizing splint therapy, physical therapy, biofeedback therapy, and anti-inflammatory medication. If necessary, a second phase of evaluation and possibly surgery of the joints, is reviewed. Fortunately, this is only indicated in a very small percentage of patients. MRI studies can be done on the joints, followed by arthrocentesis , arthroscopy, and in the rare situation, open joint surgery. This can then be followed by a third phase which includes evaluation of the dental treatment options. This can range from no treatment whatsoever, to nighttime splint wear, or to restorative, orthodontic or surgical procedures.
5. Please explain briefly the objectives and contents of the two textbooks written by you and Dr. Bennett: "Orthodontic Treatment Mechanics and the Preadjusted Appliances" and "Orthodontic management of the Dentition with the Preadjusted Appliances". Particularly, the latter, your new book, is written from a unique perspective. I like the way the book is structured. What was your intention in writing the book in such a style?
Thank you for asking about our textbooks. Our first textbook, entitled, "Orthodontic Treatment Mechanics and the Preadjusted Appliances" deals with our basic philosophy of treatment mechanics, primarily with Class I extraction and non-extraction cases. The six stages of treatment, including anchorage control, leveling and aligning, overbite control, overjet reduction, space closure and finishing are reviewed in detail in this text. Treatment suggestions are made with the preadjusted appliance during each of these stages of treatment.
Our second book, entitled "Orthodontic Management of the Dentition"(reviewed in last issue of OC, see http://www.oc-j.com/issue7/mclaugh.htm) is in no way a second edition of book one. It presents an entirely different approach than the first book. While it does incorporate all aspects of the treatment mechanics described in the first book, in particular it takes each individual tooth in the dentition and evaluates common clinical concerns that are seen in everyday practice concerning that tooth. These concerns are discussed in detail with supporting literature wherever possible. The text has a number of case reports and clinical sequences that help the orthodontist in determining appropriate diagnosis, treatment planning and treatment methods. I have found in my practice that by having these two textbooks available, I am able to show patients virtually every possible situation that may come up in the treatment of their case. Patients find it most beneficial to have these visual aids in understanding the treatment that they need.
