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Dentoskeletal effects of mini-screw assisted, non-surgical palatal expansion in adults using a modified
Priyanka Ponna1,2, Nour Eldin Tarraf1, Kerem Dalci1
1Discipline of Orthodontics and Paediatric Dentistry, School of Dentistry, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2010, Australia.
Objectives:
This study assessed the dental and skeletal effects of pure bone-borne, non-surgical maxillary expansion, using a modified force-controlled polycyclic protocol.
Methods:
Records of 17 adult patients, mean age 24.1 years; range 18-39 years, who had undergone maxillary expansion using a bone-borne Quad-expander (with 4 mini-screws), were analysed. In all patients, 0.17 mm/day of expansion was completed for 1 week, followed by a cyclic protocol of expansion of forward and backward turns until the force needed to turn the expander was below 400 cN, assessed weekly. After this, expansion continued at a rate of 0.17 mm/day until the desired amount of expansion was achieved. Cone beam computer tomography scans were taken pre- and post-expansion.
Results:
The mid-palatal suture was successfully opened in 100% of patients included in this study. Axially, the amount of skeletal opening at the posterior nasal spine was 61% of the anterior nasal spine. Expansion was pyramidal in the coronal plane. Significant increases at the dental and skeletal levels were achieved, with changes at the skeletal level reaching 73%. The alveolar bone angle increased more than the angular changes at the molars and premolars.
Limitations:
This is a retrospective study with short-term results.
Conclusion:
The Quad-expander, with a force-controlled polycyclic expansion protocol, effectively produced a significant increase in maxillary width in skeletally mature subjects in the short term.
