The role of double-step advancement genioplasty and bilateral coronoidectomy in Nager Syndrome: A case report

Aim: To report the surgical management of bilateral mandibular coronoid processes hyperplasia and mandibular retrognathism associated with trismus and convex facial profile in an individual diagnosed with Nager syndrome (NS).

Case report: A 21 years old female was referred to the Department of Oral and Maxillofacial Surgery, presenting limited mouth opening and an unpleasant convex facial profile. The tomography exhibited hyperplasia of mandibular coronoid processes with no evidence of intracapsular ankylosis of the temporomandibular joint. The treatment objectives were to increase mouth opening through a bilateral coronoidectomy and gain chin projection using the double-step advancement genioplasty technique. The 9-month postoperative follow-up revealed a 22.22% (6 mm) gain in jaw opening, improved masticatory function, and facial profile.

Conclusions: The NS is a complex craniofacial anomaly due to its clinical heterogeneity. Thus, treatment planning must be done individually, considering the patients' main complaints and respecting the limitations regarding anatomy and availability of proper surgical materials. In the present case, a bilateral coronoidectomy associated with immediate physiotherapy improved the patient's mouth opening, and the double-step genioplasty promoted a much more significant chin advancement than would be obtained with the single-step traditional osteotomy.