The Impact on Airway Space Following Mandibular Condylar Replacement Surgery

Objectives: Evaluate the relationship of bilateral condylar replacement and mandibular advancement surgery on the upper airway.
Methods: Thirty subjects exhibiting retrognathic chin positions due to degenerative joint disease had bilateral condylar replacement (TMJ Concepts, Ventura, CA) and mandibular advancement surgery by one surgeon. Oropharyngeal airway space (volume and minimum cross-sectional area) were measured utilizing acquired 3D-CBCT’s pre-operatively -T1, post-operatively -T2, and one year after surgery -T3 utilizing InVivo5 advanced 3D imaging software (Anatomage, San Jose, CA) at the level of C1, C2, and C3 cervical vertebrae. Mandibular advancement changes were obtained through cephalometric superimposition also utilizing the InVivo software Four categories of advancement were established: 1 (0-2mm); 2 (2-10mm), 3 (10-15mm) and 4 (more than 15mm).
Results: All oropharyngeal airway measurements increased, T1-T3 (p<0.05). ANOVA test showed that mandibular advancement was significantly associated with increase in airway volume (p=0.03). Similar observations were attained comparing the percentage volume change over time with mandibular advancement (Kruskal-Wallis test; p=0.04). Inter-operator measurements correlated significantly as shown by the analysis of intra-class correlation coefficients (ICC) which were all greater than 99%.
Conclusions: Oropharyngeal airway space increased after bilateral condylar replacement and mandibular advancement surgery.