The timing of orthodontic treatment, including dentofacial orthopedics, has variable opinions expressed in the specialty. The literature supports early treatment for many, but not all, conditions. Early intervention with rapid palatal expansion has support that is based on both anatomical and dental development. Five key reasons for early expansion are discussed in this article, which gives additional support for early application of this beneficial procedure.
1. Anatomy studies of the mid palatal suture document that the suture becomes more complex with maturity. The suture system of younger patients is very responsive to the orthopedic intervention of the expander. This benefits the maxillary complex because less pressure is needed to achieve the desired skeletal expansion. When less pressure is used we reduce the risks for negative consequences to the buccal bone. As a patient matures, there is more risk of teeth tipping with expansion and less stable orthodontic expansion rather than orthopedic expansion.
2. Use of an expander during the early mixed dentition allows the use of the primary teeth to serve as anchors for the expansion appliance. This has important benefits to the permanent dentition that eliminates the potential negative effects that can include dehiscence of the buccal bone, gingival recession and root resorption. Expansion appliances use the strength of the roots and surrounding bone of the teeth they are attached to. In consequence, those teeth and supporting bone carry the lateral pressure of the expansion as the suture opens. When primary teeth are used to support the expander, the succedaneous bicuspids and canines have not borne any of the expansion pressure. The newly erupting teeth only benefit from the additional space development the expander has created. The acrylic bonded expander is easily constructed to adapt exclusively to the primary dentition, and has the added benefit of spreading the attachment over several teeth on each side. A banded hyrax appliance can be attached to second primary molars and canines, or the permanent first molar and primary first molar. Studies have reported using a Haas expansion appliance attached to the second primary molars and primary canines is successful and stable.
3. In most cases the reason for expansion is because of the maxillary constriction or crossbite. The expansion appliance is placed into the palatal vault area as deeply as possible without impinging on palatal tissues. As a consequence the appliance will create a temporary interference with speech and swallowing. The adaptation of the neuromuscular system in younger patients is faster and will adapt more readily than older adolescent patients.
4. When teeth erupt into a prepared site with adequate bone and soft tissue support, it is the ideal scenario for long-term stability and sound periodontal support. A similar protocol is followed when preparing a site with a graft for receiving an implant or grafting in an alveolar cleft site to receive the erupting canine. To prepare the space with expansion follows the same principles for site preparation. In a crowded developing dentition, the plan to develop eruption space will decrease the risk of ectopic eruption with a compromised gingival attachment
5. The effects of a constricted maxilla goes well beyond the dentition. We are finding more evidence that maxillary constriction can be a factor in airway restriction in children. The effects of a rapid maxillary expander can include an increase in nasal airway and improved respiratory function. As airway evaluation becomes more a part of our dental exams, the benefit of early expansion can include the improvements in airway and sleep.
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Donna J. Stenberg DDS, MS, PA, Spear Visiting Faculty and Contributing Author. firstname.lastname@example.org
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