Is Counterclockwise rotation With Double Jaw Orthognathic Surgery Stable Long Term in Hyperdivergent Class iii Patients?

Publication date: Available online 15 March 2018
Source:Journal of Oral and Maxillofacial Surgery
Author(s): Yasemin Bahar Acar, Necip Fazıl Erdem, Ahmet Hüseyin Acar, Ahmet Nejat Erverdi, Kemal Ugurlu
PurposeTo evaluate long-term post-surgical stability of counterclockwise rotation of occlusal plane (OP) with double-jaw orthognathic surgery in hyperdivergent Class III patients.MethodsThis retrospective cohort study evaluated postsurgical stability of orthognathic surgery in patients with skeletal Class III malocclusion and counterclockwise rotation of the maxillomandibular complex with an occlusal plane change of ≥ -2°. Patients were evaluated with lateral cephalometric analysis at pre-surgery (T0), immediately post-surgery (T1) and at longest follow-up (T2). Primary predictor variable was the change in OP-Frankfurt horizontal angle post-surgery. Primary outcome variable was stability of occlusal plane at longest follow-up. Other study variables were age, sex and the following cephalometric measurements: mandibular plane angle, gonial angle, SNB, maxillary height, angle of palatal plane to sella-nasion, distances of posterior nasal spine and A-point to FH, and A-point to the vertical line passing from nasion. The Mann-Whitney U test was used to compare stability groups since variables were not normally distributed. The Bonferroni correction was used to evaluate p values. Chi-Square and Fisher's exact test, where appopriate, was used to compare proportions of the groups. P<0.05 was accepted as statistically significant.ResultsThe sample was composed of 15 adult patients, mean age at surgery was 23.5 years, and 40% were male. The median duration of follow-up was 48 months (IQR: 36-60). The groups had similar demographic properties and similar surgical changes. 10 patients showed very stable results with OP-FH change ≤1°. 4 patients were considered unstable with an 2.25±0.5° change of OP-FH in the follow-up period. Change in mandibular plane angle was significant between stable and unstable subjects, being the variable that was affected the most from relapse of the OP.ConclusionThis study demonstrated long-term post-surgical skeletal stability of counterclockwise rotation of occlusal plane with double-jaw orthognathic surgery in high angle Class III patients with a median of 48 months follow-up.



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