Palatal expansion in adults: the nonsurgical approach.

A The discerning orthodontist has a treatment regimen that preferentially deals with arch deficiencies and might not necessitate extractions. Orthodontic expansion has been shown to be predictably unstable, and interproximal reduction is effective only up to a point, and so most of us use skeletal expansion in some form or another. This article is an effort to gather from the literature and personal experience a strategy for expansion in adults that is workable, predictable, and stable. I intend to demonstrate that there are benefits to expansion through surgery that are not obtainable otherwise. Although nonsurgical expansion is preferred for some adult patients, surgically assisted rapid maxillary expansion is the clear choice for others. The discussion should not culminate in yes or no but, rather, an effort to find the tipping point, a point on either side of which a superior result might be achieved. In any effort to find the difference between success and shortcoming, age should be a primary consideration. Haas indicated that orthopedic expansionwould invariably open the midpalatine suture until age 16 or 17. Melsen demonstrated histologically that, after the ages of 15 in girls and 17 in boys, both sutures consist of a narrow sheet of connective tissue with inactive osteoblasts. As the patient matures, increasingly, Sharpey’s fibers could be followed uninterruptedly across the suture. Using metal implants, Krebs showed that orthopedic expansion resulted in a ratio of sutural expansion to dental expansion of about 50% until age 13; this dropped to approximately 30% and progressively less as boys approach age 14 and older. Among girls, the drop occurred earlier and more profoundly. A healthy periodontium might be the ultimate harbinger of a successful dental response. Claffey and Shanley studied gingival thickness (thin vs thick), correlated it with the tendency toward bleeding on