Zygomatic fractures and infraorbital nerve disturbances. Miniplate osteosynthesis vs. other treatment modalities.

Abstract

The present paper reviews the results obtained with different modalities of treatment employed in isolated fractures of the zygomatic complex. Seventy-three patients were re-examined with respect to infraorbital nerve function. The results obtained suggest that the incidence of hypoaesthesia of the infraorbital nerve following fracture of the zygomatic complex can be reduced if rigid fixation is applied on the infraorbital rim. The zygomatic bone is a protruding part of the human skeleton and is therefore easily affected by trauma to the facial region. The etiology and clinical appearance of fractures of the zygomatic complex are well known and previously described in detail (Afzelius and Rosen 1980, Ellis et al. 1985, Jungell and Lindqvist 1987). Fractures of the zygomatic complex are rarely fractures of the zygoma itself but of its connection to the skull and facial skeleton, e.g. the frontozygomatic suture, the zygomatico-maxillary suture, the zygomatic arch and the infraorbital rim. A fracture of the infraorbital rim usually involves the infraorbital foramen or bone close to it. Such a fracture also extends into the orbital floor through or adjacent to the infraorbital canal. Dislocation of the fractured zygomatic complex may thus result in injury to or compression of the infraorbital nerve. Such an injury may cause numbness/hypoaesthesia/dysaesthesia in the distribution of the nerve. Accordingly, reduced infraorbital nerve function is a frequently reported sequela of fractures of the zygomatic complex. Thus impaired infraorbital nerve function prior to treatment has been reported to occur in approximately 80% of such cases (Table 1). With respect to persistent impaired function of the infraorbital nerve, the literature demonstrates varying results following different types of treatment, ranging from 22% to 50% persistent hypoaesthesia (Table 1). Interestingly, the return of infraorbital nerve function continues with an extended observation period between treatment and follow-up and it has been claimed that infraorbital nerve function may continue to improve even after one year following injury/surgery (Afzelius and Rosen 1980). Cases with persistent and disturbing impaired function of the infraorbital nerve may be considered for decompressive nerve surgery or microsurgical reconstruction of the infraorbital nerve (Mozsary and Middleton 1983). The present report is a retrospective study and aimed to evaluate the recovery of infraorbital nerve function obtained with different modalities of treatment of isolated fractures of the zygomatic complex.