Zygomaticomaxillary complex fractures : aspects of diagnosis, treatment and sequelae

<p dir="ltr">Zygomaticomaxillary Complex (ZMC) fractures are common types of midfacial fractures and are mostly sustained by young males. Surgical repair consists of either anatomical reconstruction with plates and screws or reduction without internal fixation. In the absence of functional sequelae, many reconstructions are purely cosmetic and are performed to restore facial symmetry. The main purpose of this thesis was to present novel findings and new perspectives to aid surgeons in deciding whether to reconstruct ZMC fractures.</p><p dir="ltr">Paper I presented the loss of lower eyelid bags as a previously unknown complication to orbital floor reconstructions. Sixty adult patients with surgical reconstruction of isolated blow-out fractures using either pre- or retro-septal transconjunctival incisions were included and compared with a control group of 47 adult patients with conservative management. The patients were all photographed and a grading system was created to describe bags of the lower eyelids. All 25 patients with surgical treatment and a visible lower eyelid bag on the non-injured side of the face suffered lower eyelid bag asymmetry compared to 1 out of 11 patients with conservative management (p < 0.001). Patients with asymmetry appeared to have lost the lower eyelid bag on the operated side of the face and there was no association with the type of transconjunctival incision.</p><p dir="ltr">Paper II introduced the Volume Difference Along the External Surface (VDAES) as a novel method of measuring zygomatic bone asymmetry. The computer tomography (CT) scans of 50 male and 50 female patients without fractures or deformities to the facial skeleton were analyzed using iPlan Cranial (Brainlab AG, Germany). Measuring consisted of image alignment, creation of a 3-dimensional (3D) object of the zygomatic bone, mirroring across the midline and manual highlighting of asymmetry on axial image cuts. Median VDAES was 1.48 cm³ with a significant difference between males and females (p=0.003). There was no significant association with zygomatic bone volume. The inter-class coefficient (ICC) value for both intra- and inter-rater reliability was 0.99, suggesting that the method, if further developed, has the potential of aiding surgeons in evaluating zygomatic bone asymmetry.</p><p dir="ltr">Paper III described long-term outcomes of patients with ZMC fractures and different treatments by accounting for the perspectives of both patients and surgeons. Patients with unilateral ZMC fractures between 2007-2018 were invited to follow-ups where they submitted a questionnaire, underwent a clinical examination and were photographed. A review panel consisting of three experienced facial fracture surgeons evaluated all photographs and CT scans. The study sample had a follow-up duration of more than 6 years and consisted of 180 patients, of which 137 were treated by surgery. There were marked differences in the ways patients and surgeons perceived sensory disturbance, trismus and diplopia. Surgeons were more prone to detect malar asymmetry on photographs (28.9%) or to predict asymmetry on CT scans (28.9%) compared to patient's reports (11.7%). Predicted asymmetry on CT scans did not correlate to photo-detected or patient-reported asymmetry.</p><p dir="ltr">Paper IV described long-term outcomes of patients with ZMC fractures and surgical treatment. Patients with unilateral ZMC fractures between 2007-2018 were invited to follow-ups where they submitted a questionnaire, underwent a clinical examination and were photographed. A review panel consisting of three experienced facial fracture surgeons evaluated all photographs and CT scans. The study sample had a follow-up duration of more than 6 years and consisted of 137 patients, of which 108 were treated by open reduction with internal fixation (ORIF) and 28 by closed reduction (CR). Patient satisfaction was high (97.8%) and dissatisfaction was mainly related to hypesthesia. On CT scans, surgeons predicted higher rates of malar asymmetry in patients with 1-point fixations (31.6%). On questionnaires and photographs, malar asymmetry was more common in patients with 3-point fixations (14.5% and 38.2%, respectively).</p><p dir="ltr">Paper V explored the loss of lower eyelid bags and resulting lower eyelid bag asymmetry in patients with ZMC fractures and different treatments. Patients with unilateral ZMC fractures between 2007-2018 were invited to follow-ups where they submitted a questionnaire and were photographed. The study sample had a follow-up duration of more than 6 years and consisted of 104 patients with a visible lower eyelid bag on the non-injured side of the face. Lower eyelid bag asymmetry was seen in 42 patients (40.4%) and was significantly associated with a lower eyelid incision (p=0.008). Among patients with lower eyelid bag asymmetry, 16 were not treated with a lower eyelid incision.</p><p dir="ltr">In conclusion, this thesis presented lower eyelid bag loss as a cosmetic complication that is primarily associated with the lower eyelid incision and introduced a concept by which zygomatic surface anatomy can be evaluated. Furthermore, differences were observed in the ways long-term sequelae were perceived, in particular malar asymmetry. Overall, the findings suggest that selected ZMC fractures can be treated using less invasive methods. More knowledge is needed to understand the dynamics of soft tissue changes and the different ways skin and subcutaneous tissue react to trauma and surgery.</p><h3>List of scientific papers</h3><p dir="ltr">I. <b>Rahbin S,</b> Liakos A, Alinasab B. Loss of Malar Bags in Lower Eyelid in Orbital Blow Out Fracture Reconstruction Following Pre- or Retro-Septal Transconjunctival Incision. J Craniofac Surg. 2020 May/Jun;31(3):769-771. <a href="https://doi.org/10.1097/scs.0000000000006103" rel="noreferrer" target="_blank">https://doi.org/10.1097/scs.0000000000006103</a></p><p dir="ltr">II. <b>Rahbin S,</b> Toufani T, Al-Khabbaz AM, Lindblom J, Sunnergren O, Darabi H, Qureshi AR, Alinasab B. The Volume Difference Along the External Surface of the Zygomatic Bone: A Novel Method of Measuring Zygomatic Bone Asymmetry. J Craniofac Surg. 2022 Mar-Apr 01;33(2):463-468. <a href="https://doi.org/10.1097/scs.0000000000008186" rel="noreferrer" target="_blank">https://doi.org/10.1097/scs.0000000000008186</a></p><p dir="ltr">III. <b>Rahbin S,</b> Sunnergren O, McBride E, Darabi H, Alinasab B. Differences Between Patient and Surgeon Perspectives: A Long-Term Follow-Up of 180 Patients With Zygomaticomaxillary Complex Fractures Following Either Conservative or Surgical Treatment. Craniomaxillofac Trauma Reconstr. 2024 Dec;17(4):NP121-NP130. <a href="https://doi.org/10.1177/19433875231208463" rel="noreferrer" target="_blank">https://doi.org/10.1177/19433875231208463</a></p><p dir="ltr">IV. <b>Rahbin S,</b> Sunnergren O, McBride E, Darabi H, Alinasab B. Does More Invasive Surgery Result in Higher Patient Satisfaction? A Long-Term Follow-Up of 136 Zygomaticomaxillary Complex Fractures. Craniomaxillofac Trauma Reconstr. 2024 Dec;17(4):NP271-NP280. <a href="https://doi.org/10.1177/19433875241286544" rel="noreferrer" target="_blank">https://doi.org/10.1177/19433875241286544</a></p><p dir="ltr">V. <b>Rahbin S,</b> Sunnergren O, Darabi H, Alinasab B. Loss of lower eyelid bags in patients with zygomaticomaxillary complex fractures. [Manuscript]</p>