Retromandibular reduction of medially dislocated condylar process fractures

BACKGROUND Condylar process fractures account for one-third of all mandibular fractures, and the distal fragment is prone to dislocate to the medial side due to the pulling of the lateral pterygoid muscle. Retromandibular approaches are commonly used, but the intraoperative view becomes limited in medially dislocated fractures. This study summarized a series of cases of retromandibular reduction for medially dislocated condylar process fractures and described our supplementary procedure to realign the dislocated condylar process. METHODS Nine patients with medially dislocated condylar process fractures underwent surgical correction from January 2012 to December 2016. In 6 of them, it was possible to realign the fractures with a conventional retromandibular approach, but for 3 cases of severe dislocation to the middle cranial fossa, a supplementary transoral procedure was carried out. The angle difference between the ramus and condyle, ramus height, and maximal mouth opening (MMO) were evaluated. RESULTS All 9 cases were restored to the proper anatomical alignment without any major complications, and postoperative images revealed successful union. The angle difference was 8.94°±4.11° preoperatively, and 0.99±0.49° at the 6-month follow-up. The pretreatment ramus height difference was 6.12±6.09 mm, and the postoperative difference was 0.18±0.10 mm. These changes after surgery were statistically significant. The MMO before surgery was 11.44±3.0 mm, and the postoperative MMO was 37.2±2.9 mm, reflecting a significant increase after reduction. CONCLUSIONS Retromandibular reduction is a useful method in medially dislocated condylar process fractures, and additional transoral assistance should be considered to realign condylar processes that severely dislocate to the middle cranial fossa.