Surgery first for orthognathic patients?
Huang CS, Hsu SS, Chen YR. Systematic review of the surgery-first approach in orthognathic surgery. Biomed J 2014;37:184-90
Traditionally, comprehensive orthodontic treatment for alignment of the dental occlusion, incisor decompensation, tooth rotation, and arch coordination is done before orthognathic surgery. Recently, there has been a trend toward the surgery-first approach, in which the preoperative orthodontic setup is done 1 to 2 months or immediately before the surgery. Three retrospective cohort analyses and 11 case reports for the surgery-first approach were reviewed. The overall conclusions for the long-term outcomes of the surgery-first approach were the following: (1) the patients’ facial esthetics and dental functions were improved early in treatment rather than after a period of possibly years; (2) the patients’ swallowing and speech functions improved after surgery; (3) there were faster rates of orthodontic tooth movement immediately after surgery, thus reducing overall treatment times; (4) the patients’ cooperation improved during the rest of the orthodontic treatment; (5) orthodontic tooth movement was easier after restoration of the normal functional and anatomic relationships of the bony skeleton and surrounding soft tissues; and (6) stability of the skeletal results in the transverse, vertical, and sagittal dimensions was equal to, or in some cases superior to, that achieved with the more traditional orthodontics-first approach. Some disadvantages of the surgery-first approach were a higher bond failure rate, difficulty in bending the surgical wire to fit into the unleveled dentition, the requirement for more surgical movement to compensate for postoperative orthodontic movement, the impacted mandibular third molars, and the postsurgical occlusal instability. In surgery-first patients, it is important to obtain a precise diagnosis coupled with detailed treatment planning, including an accurate prediction of the postoperative orthodontic dental alignment; provide appropriate incisor decompensation and arch coordination; and allow for occlusal settling to take place. Further studies, especially prospective cohort studies or randomized controlled trials, are needed to provide additional clinical evidence.
Reviewd by Khushbu Patel
Kuroda S, Tanaka E. Risks and complications of miniscrew anchorage in clinical orthodontics. Jpn Dent Sci Rev 2014;50:79-85
Miniscrews have been overwhelmingly accepted in orthodontic practice over the past 15 years. New inventions and better ways to use and improve existing products are associated not only with benefits, but also with certain risks and complications. The purpose of this article was to let practitioners know about the risks and complications associated with miniscrews. Fracture, failure, tissue damage, and pain are associated with miniscrews and should be considered by the clinician and carefully explained to the patient before treatment. Fractures can occur with both insertion and removal of the miniscrews and are closely associated with excessive torque. Where cortical bone is thicker in the mandible vs the maxilla, more torque is needed to insert the screws; therefore, they have a higher fracture rate. To help prevent fractures, the screwdriver head must be (1) positioned on the same axis of the screw, (2) turned slowly, and (3) turned by using a driver with a torque limiter. Screw failure has a long list of host factors, and failure typically occurs within the first week after placing the screw. Cortical bone and the proximity to adjacent roots have been shown to be 2 major factors. Oblique placement increases the percentage of cortical bone contact and decreases the chance of contacting any roots. Hard tissue damage is mostly associated with root damage. Recommendations are placement in wide interradicular areas, with a smaller screw size and an oblique path of insertion. Soft tissue damage occurs with slippage during insertion, miniscrew auxiliary irritation, and placement into nonkeratinized tissue. Pain and discomfort are limited to less than 10% of patients 1 day after placing miniscrews with a flapless procedure. Increases in success rates are closely associated with decreases in risk factors.
Reviewed by Kevin Walker