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mandibular anterior centrals are not allowed behind the acrylic pad in the normal maxillary and mandibular relaxed position. The tip of the acrylic pad is curved and behind the pre-treatment positioned mandible. It is very comfortable with a narrow, thin, small anterior acrylic plate (Figure 3). It is strong, durable and, with the anterior thin fixed ramp, no wider than the middle of the maxillary lateral incisors, the LCR is excellent at correcting mandibular deficiency and anterior tongue thrust. 4. Careful pre-treatment analysis, diagnosis and treatment planning needs to be done to ensure that the mandible, when placed forward, will enhance the profile of the patient. The anterior alignment must be in the exact desired position to achieve the results wanted by the dentist and the patient. It also has to be precluded with proper maxillary anterior positioning, widening and correcting maxillary anterior arch form. That segment of maxillary treatment needs to be done before the LCR Appliance is placed. If the closed mandible is not in the preplanned position, and the treatment places the mandible in a less desired place, then the final fixed position of the mandible may require much more treatment. Careful pre-treatment analysis and planning is necessary to insure an esthetic, functional and pleasing final position. One necessary part of that planning is to have the Class II patient move his/her lower mandible forward to the desired post-treatment position during the initial interview. Observe the lateral profile of the patient from the side, as well as have any parents/guardians observe the desired post-treatment position. Be sure to get the parents/guardians consent before proceeding. Also, in planning the use of the LCR Appliance, it is necessary to determine the position of the maxillary anterior segment. This can best be done with your diagnosis which includes the ceph analysis, overbite measurement, and Mew indicator or Petit measurement line. If the maxillary anterior segment needs intruding, retruding, widening or other correcting, then these functions should be performed before you begin with the mandibular arch treatment. 5. The patient absolutely has to breathe through his/her nose with the teeth together and the mouth closed. Patients wearing any anterior mandibular protraction appliance will not respond to proper direction of growht nor to the controlled amount of growth while mouth breathing. It has been reported many times that at least six different adverse problems can occur with mouth breathers. a. The patient obtains no growth. Or, mouth breathing may deter both growth and proper growth changes. b. Mouth breathing can change the direction of and location of growth. This can cause an irreversible change to the glenoid fossa and posterior and superior condylar areas, plus a steeper, higher mandibular gonial angle. c. Open anterior configuration: Mouth breathers who wear an anterior protraction appliance sometimes end up with an anterior open bite. This is coupled with a more severe increase in tongue thrust and “open bite� swallowing. The LCR Appliance, if used correctly, will prevent this. d. Posterior prematurities may result, especially on protrusive and balancing movements, if the maxillary arch is not widened to compensate for the anterior advancement. 24

Figure 3

e. If a patient does not keep the teeth together and the mouth closed at night while wearing triangular elastics, it places the dentition in a difficult configuration making progressive therapy much more difficult. Note: The author and inventor of the LCR Appliance wants to emphasize here that triangular elastics should always be worn at, night to position the teeth closed at night or while sleeping. Elastics greatly enhance the growth potential and direction as it would in similar cases with the Twin Block, Rick-a-Nator; or Keller appliances. Age Of Patient The Loudon Chateau Repositioning (LCR) Appliance should be used before the age of 16 years to insure optimum success. Use after age 16 may be unpredictable. The success rate may drop off very dramatically, an acquired or dual bite may result, or the time for treatment may be increased substantially. While Brendan Stack has shown that remodeling of the glenoid fossa occurs with permanent condylar repositioning, he does not say that growth of the mandible can or will occur after 16 years of age. The author has viewed records of adult patients who have worn appliances similar to the LCR Appliance. In some of these adult patients after 2-3 years of proper repositioning treatment, permanent anterior repositioning and growth has occurred. However, treatment time was extended from 10 months to 24-36 months, and was not guaranteed to be stable. After adult protraction treatment, many practitioners use a retainer with an anterior guide ramp which holds the patient in the anterior position. Preparation Of The Maxillary Arch Prior To The Loudon Chateau Repositioning (LCR) Appliance Treatment We must remember that the greatest maxillary/mandibular discrepancies are in Class II, division 1 children who have a tongue thrust. This appliance helps direct the tongue in correcting the tongue thrust swallow, and holds the tongue in place 24 hours a day to train the tongue at the same time. It should be noted that when the anterior maxillary teeth are flared, one or two pretreatment widening and retruding (2 X 4 utility arch) appliances may be used for maxillary arch preparation and development, before the Loudon Chateau Repositioning (LCR) Appliance is placed. In most instances it IJO

VOL. 25

NO. 3

FALL 2014

International Journal of Orthodontics  
International Journal of Orthodontics