head and neck posture displaying excessive curvature of the cervical vertebrae from thrusting the chin forward to help open the airway is common. Flaccid lip musculature and narrow nares become observ-able due to the long-standing mouth breathing. Imagine the patient undergoes maxillary expansion treatment that effectively increases the total cross-sectional volumetric area of the airway, but no efforts are made to break the habit of mouth breathing. No efforts are made to improve the weak flaccid lip musculature or stop the teeth-apart, open-mouth resting posture. No reeducation effort is made to reverse prior indoctrination that nasal spray, nasal surgery, allergy testing and treatment, or other palliative care is necessary— with the implication that no cure is available. The unsaid message is often that such problems are genetic and, much like height, hair color and eye color, immutable. The patient’s unmet needs therefore result in preventable relapse and the return of malocclusion beginning the moment retainer wear ceases. Now, let’s imagine functional matrix-focused staging of treatment and consider possible improved outcomes. A hyrax-type maxillary expander creates maxillary expan-sion, but it does not cease when a crossbite is seen to be corrected or a specific inter-molar arch width is achieved. The expansion is contin-ued until full buccal crossbite can be observed. If two expanders are needed, then consecutive appli-ances should be planned to achieve the result. In some cases, the patient’s pre-existing deficiency may be so severe that only a smaller screw can be accommodated; in other cases, premature removal results due to cementation difficul-ties or the patient’s emotional state requiring a pause. These are reasons for further expansion. An intentional, functional matrix-focused treatment plan would consider the maximum lateral displacement of bicuspids and molars that would displace the buccinators, laterally changing the matrix. The goal would be to create a similar effect to that of the Frankel appliance’s buccal shields facilitating lower arch expansion. Since cone beam studies reveal that only about 30 percent skeletal expansion results from traditional RPEs, 50 percent results from splint style RPEs, and 60 percent results from MARPEs, it is prudent to plan to lose 70–40 percent of observed expansion from the relapse of tooth tipping and alveolar bending. The perception of expansion efforts to overcorrect deficient transverse growth appears exaggerated. Temporary full buccal crossbite occlusal is uncomfortable to see. Despite concern that a telescoping malocclusion may develop, it is not observed clinically due to changes in the functional matrix. Continuing the functional matrix-focused treatment plan, removal of the hyrax screw obstruc-tion should follow completion of expansion to facilitate a return to normal tongue position after no more than six to 10 weeks of having the screw in place after stop-ping activations. Providing an ESSIX-style retainer, leaving the palate unobstructed and beginning lip competency nasal-breathing exercises (i.e. taped lips practice) can establish a return to nasal breathing with normal tongue posi-tion. The lip-tape nasal breathing exercise will also alert and train the patient to keep the teeth together when he or she feels the tug of the tape as the jaw drops. In cases where patients’ pretreatment swal-low and tongue resting position was noted as TBT, the exercise will retrain the swallow. (An exception is in cases of large open bites where the tongue can still fit between the teeth even when clenching.) Two additional benefits result from including the lip-tape exercise in the treatment plan. The first is due to the distinct possibility that wear-ing a hyrax expander in the palate for several months may start or worsen a dropping of the jaw and abnormally low or TBT problem. The second benefit is that the lip-tape exercise serves as a functional test to confirm if nasal breathing is possible. This is helpful for borderline deci-sions whether to expand again or refer the patient to an ENT. Keep in mind that the lip-tape exercise is typically well-accepted when first introduced as a daytime exercise and followed only after success by attempted night wear. If a baseline sleep study is available, it could be repeated, or the patient could be referred to a myofunctional therapist. Many other waypoints occur along a comprehensive orthodontic treatment plan in which a func-tional focus may be beneficial. Some of these may be best if always included, and others can be deployed on an as-needed basis. Practitioners can use the new discoveries, advancements and tech-nologies to better tailor treatment plans for maximum patient satisfac-tion and better clinical results. www.orthodontics.com Winter 2025 17
Journal of the American Orthodontic Society Winter 2025: Page 17
