- Meeting abstract
- Open Access
Surgery first - prediction of surgical movements based on untreated cases
© Stamm et al; licensee BioMed Central Ltd. 2014
- Published: 12 December 2014
- Patient Record
- Valid Predictor
- Blinded Trial
- Mandibular Advancement
- Untreated Case
The aim of the study was to test the following hypothesis: There is no difference in orthognathic surgery protocols planned on pre-treatment patient records (Surgery First protocols) compared to surgery protocols planned on patient records after orthodontic preparation (Surgery Late protocols).
Study type: Prospective, randomised, semi blinded trial. One hundred fifteen traditional treated orthognathic surgery cases were included based on inclusion and exclusion criteria. Pre-treatment records of the 115 cases were presented to a surgery team (surgeons, orthodontists) to generate a Surgery First protocol. The Surgery First protocols were then compared with the true (Surgery Late) protocols of the treated cases. The statistical power was 95%.
Surgery First and Surgery Late protocols of the same cases differ significantly. Impaction of the maxilla is the most predictable surgical movement with a mean error radius of 2.4 mm ± 1.9 mm for each measurement landmark. Maxillary advancement showed an error radius of 3.2 mm ± 2.9 mm. The highest errors were found in mandibular advancement / set back with 6.3 mm ± 4.3 mm on each side. Overall the errors add up to 14.8 mm ± 6.8 mm. Angle classes do not differ significantly concerning the planning errors.
The hypothesis that there is no difference between Surgery First and Surgery Late protocols must be rejected. Planning errors with the Surgery First concept are not predictable. The post-operative malocclusion generated with Surgery First could lead to situations which are not manageable with orthodontics. There is a high risk of unfavourable occlusion and further corrective surgery at the end of treatment. The initial Angle class is not a valid predictor of low or high planning errors.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.