Mandibular fractures: repercussion on the atlanto-axial joint and acute cervical sprain

Objective - Our previous research on facial dysmorphic pathology were able to show that maxillofacial asymmetries are associated with tridimensional modifications of the cranio-axial-cervical structures. These studies also showed that such cranio-cervical alterations, which can lead to arthropathies of the small vertebral articulations and scoliosis, may cause cervical pain syndromes. Facial fractures result in an acute musculoskeletal asymmetry characterized by the spatial modification of the muscular vectors which causes a post-traumatic pathological and asymmetrical rearrangement of facial structures. Therefore we hypothesized that, as in asymmetrical dysmorphosis , in facial fractures the musculoskeletal displacement can also cause cranio-axial modifications that could expose patients to subsequent cervical clinical disorders. Methods - 315 non consecutive cases of displaced mandibular fractures, 193 males (61.26%) and 122 females (38.74%), 18-36 years of age, treated from June 2006 to June 2012, were selected according to the following criteria: absence of direct cervical trauma, absence of preexisting cervical pathologies and facial asymmetric dysmorphosis. Single fractures amounted to 220 cases (69.84%), multiple fractures to 95 cases (30.16%). Results - In all cases CT showed a rotation of the atlas, ipsilateral to the side of single fractures, and the subluxation of the cranio-cervical joint (Kappa Coefficient = 1,000). Parasymphisis fractures showed greater joint dislocation than fractures of the angle and ramus (p = 0,0001). In bilateral fractures, joint displacement appeared in the side of greater muscular imbalance. Vertical derangement of the joint has been observed in 79.65% of single fractures and in 20.35% of multiple fractures (p = 0,0046). A Control Group made up of 20 patients, 10 males and 10 females, aged from 19-24 (mean-range: 21.6) suffering from acute isolated cervical sprain (whiplash) showed no spatial alterations of the atlanto-axial joint. Conclusions - Our research showed and delineated the physiopathology of cervical sprain in mandibular fractures. It appears that 16.19 % of all patients with displaced mandibular fractures showed cervical disorders at long-term follow-up ( p=0.0002).