Therapy of a lateral open bite using an occlusal splint with anterior jig and botulinum toxin after surgical repositioning of a unilateral mandibular neck fracture

Condylar fractures are the type of jaw fractures that occur most frequently. Complications such as abnormal or malfunctional occlusion can arise from the treatment of condylar fractures. These, in turn, can cause severe symptoms that may require corrective surgery. The etiology of this postoperative complication has not yet been fully clarified; one possible cause is considered to be the protrusive traction of the masticatory musculature. In the case reported here, the patient presented with a lateral open bite and limited mouth opening after the repositioning of a unilateral fracture of the mandibular condyle. Bilaterally, the muscles of mastication were prominently developed. Imaging procedures revealed a postoperative anterior condylar position. The patient had a forced bite, probably of muscular origin, and received multimodal treatment based on an occlusal splint with an anterior jig and botulinum toxin injections. The lateral open bite was slightly reduced, and mouth opening was still slightly limited after injection of the toxin. A few days after the use of the anterior jig, the lateral open bite was closed, and a normal range of mouth opening was achieved. This multimodal therapy could be a possible strategy for the correction of post-interventional malocclusion resulting from a mandibular neck fracture. Keywords: condylar fracture, mandibular neck, lateral open bite, malocclusion, limited mouth opening, masseter muscle hypertrophy, occlusal splint, anterior jig, botulinum toxin