I too was taught in dental school that the midpalatal suture fuses after a person has stopped growing (around 18-23 years old). As with a number of other things I was taught in dental school, modern research has proven that this simply is NOT true. The midpalatal suture not only does NOT fuse after normal growth occurs but remains open for many years. I have successfully developed the palates of NUMEROUS adult patients with great success. Some will say I am only moving teeth but those people would be thinking and speaking with outdated paradigms. Current research and literature has actually used new 3-D imaging to measure and quantify the volume of NEW BONE that forms utilizing removable appliances that take advantage of the phenomena known as "sutural homeostasis" to actually develop the palate.The outdated paradigm is that once a patient stops growing they are stuck with whatever shape and size of palate they have. The new paradigm is that every person is born with a genetic potential and if a person's palate is underdeveloped (not enough room for their teeth to fit) then their genetic potential has not been met. This genetic potential can still be met using a comfortable appliance that stimulates BONE FORMATION along the midpalatal suture (taking advantage of "sutural homeostasis").As you can hopefully tell, I am passionate about this dental topic because there is so much misinformation being disseminated that is not only aesthetically compromising to patients (makes for far less attractive faces and smiles) but also potentially causes a myriad of medical problems, including TMJ Dysfunction and sleep apnea.Do your own research and then go with the treatment that makes the most sense to you. It won't take long to do a simple Internet search on "adult palatal expansion" and see how many doctors are successfully treating patients using newer dental technology and paradigms. I will caution you against "rapid palatal expansion" as this is damaging to the midpalatal suture. It will actually fracture the suture and cause scaring which will result in unwanted relapse. Palatal development must occur relatively slowly (no more than a quarter turn of an expansion screw every 5-7 days). The typical adult palatal development can be accomplished in a year or less using comfortable, easy-to-wear appliances.Good luck!