LETTERS FROM OUR READERSTo: Editor, The Angle Orthodontist, RE: Handelman CS, Wang L, BeGole EA, Haas AJ. Nonsurgical rapid maxillary expansion in adults: report on 47 cases. Angle Orthod. 1999;70:129–144.
The article on this subject published in the April edition of your journal must surely be one of the most significant ever published on this subject. It confirms the beliefs of our mentor, Edward Angle, and confounds the pessimists who for many years have claimed that permanent expansion is a dream. Admittedly, the patients in this paper were selected, but the esthetic benefits of expansion were clearly demonstrated, and we must accept that this can be a permanent reality for some adults. Messrs Haas and Handleman should be congratulated for persisting with this development despite being rejected for so many years.
May I make an important point? Right through the last century, opinion was divided between those who recommended slow expansion of half a millimeter per week and those who recommended rapid expansion of 2 to 4 mm/wk. In 1977, on the basis of both biological and clinical evidence, I suggested a semirapid rate of 1 mm/wk as being ideal.1 Subsequently, I showed that this rate was very stable over a period of two and a half years in a consecutive series of 25 children and appears to avoid damage from excessive strains.2,3
I note that Dr Haas now recommends the same rate of expansion for adults but refers to it as “slow,” and I wonder if it might be best if we all used the same term, “semirapid,” to emphasize the significance of this precise rate when separating the palatal shelves.
In my experience, many orthodontists aim for 1 mm/wk, but because of noncompliance or loose screws finish with one-third or one half millimeter per week when measured over several weeks. This can make a crucial difference to the long-term results and may be one of the reasons why my findings on children and the current findings on adults appear to differ from almost all those of the past.
An additional benefit can be achieved if the screw is opened one-eighth of a turn every day rather than a quarter turn every other day. Not only does this provide a more continuous force, but also it is easier to remember and avoids the crushing of the periodontal membrane at each opening. The semirapid rate also enables the palatal vault to be covered on adults and children without inevitable soft tissue sores and permits the use of removable appliances on both groups with less tilting of the buccal segments.