| dc.description.abstract | Purpose
To evaluate and compare the skeletal and dentoalveolar effects produced by two maxillary expansion protocols in skeletally mature, non-growing adults.
Materials and Methods
The study sample included 40 (15 female, 25 male) treated subjects with an average age of 32.4 ± 12.2 years at initial records (T0). All subjects were treated by two practitioners in a private practice setting. Upon recruitment, subjects were placed into three different surgical expansion groups, initially based on sex and age. Preoperative CBCT scans acquired at the initial appointment were utilized to further classify treatment groups based on radiographic modifiers. The two protocols, Type II and Type III, used the same micro-implant skeletal expander type-2 design (MSE-2, Great Lakes Orthodontics). Type II protocol consisted of an expander with four bi-cortical micro-implant screws, midline corticopunctures approximately 2 mm apart, and a vertical midline osteotomy. Type III protocol consisted of Type II protocol in adjunct with horizontal anterior maxillary osteotomies. Following adequate expansion and prior to appliance removal, post-expansion CBCT scans were acquired for T1 records. The average time difference between pre- and post-expansion scans was 0.6 ± 0.5 years. The scans were evaluated to determine the skeletal and dentoalveolar changes.
Results
Type II and Type III protocols showed significant increase from pre- to post-expansion for all variables except IOW. Anteriorly, AABW, AABWI, and AAPW showed significantly greater changes in Type III compared to Type II. Posteriorly, there were no significant differences between the changes. Dentally, ICW showed significantly more changes in Type III than Type II; however, the difference in changes at IMW was not significant.
Conclusions
Type II and Type III protocols are equally effective and successful at achieving expansion in the posterior region. Type III protocol can produce more significant expansion in the anterior region than Type II protocol; however, significant anterior changes, especially at ICW, are not usually desired for orthodontic purposes. This suggests that the less invasive Type II protocol is sufficient in producing significant changes in the region of interest for maxillary deficient skeletally mature, non-growing individuals. | |
