Risk factors for fractures after marginal mandibulectomy for head and neck cancer multicentre study

Marginal mandibulectomy (MM), which involves partially interrupting the height of a mandibular segment, is discussed when head and neck cancer is located close to the mandible because of the potential risk of secondary mandibular fracture. To determine the incidence of secondary mandibular fracture after MM and the associated risk factors we conducted a multicentre study in 3 tertiary cancer care centers. We included all patients with a malignancy requiring MM who completed treatment between January 2013 and December 2023. Of the 432 identified patients, 190 patients were included. 24 patients (12.7 %) experienced a secondary mandibular fracture within 23.5 [13.8; 36.6] months following the MM. The majority of patients were male(74.2 %) with an average age of 62 years (±10.70). In multivariate analysis, posterior location of the MM (OR = 4.08, IC 95 % 1.28 to 13.02), residual mandibular height of less than 10 mm (OR = 3.25, IC 95 % 1.05 to 10.05), and MM length of greater than 45 mm (OR = 4.23, IC 95 % 1.35 to 13.22) were statistically associated with secondary mandibular fractures. Segmental mandibulectomy, consisting of a complete interruption of a mandibular segment should be considered as an alternative to MM in cases of posterior location, significant length of MM or residual mandibular height less than 10 mm.