OBJECTIVE: The orbital floor is frequently involved in head trauma. Current evidence on the use of reconstruction materials for orbital floor repair is inconclusive. Accordingly, this study aimed to compare the impact of polydioxanone (PDS) foil thickness on reconstruction of the orbital geometry after isolated orbital floor fractures.
METHODS: Standardized isolated orbital floor fractures were symmetrically created in 11 cadaver heads that provided 22 orbits. PDS foils with thicknesses of 0.25-0.5 mm were inserted. Computed tomography (CT) scans of the native, fractured, and reconstructed orbits were obtained, and orbital volume, orbital height, and foil bending were measured.
RESULTS: Orbital volume and height significantly (p < 0.01) increased after the creation of isolated orbital floor fractures and significantly (p = 0.001) decreased with overcorrection of the orbital geometry after orbital floor reconstruction with PDS 0.25 mm or PDS 0.5 mm. The orbital geometry reconstruction rate did not differ significantly with respect to foil thickness. However, compared to PDS 0.5 mm, the use of PDS 0.25 mm resulted in quantitatively higher reconstructive accuracy and a restored orbital volume that did not significantly differ from the initial volume.
CONCLUSIONS: Orbital floors subjected to isolated fractures were successfully reconstructed using PDS regardless of foil thickness, with overcorrection of the orbital geometry. Due to its lower flexural stiffness, PDS 0.25 mm appeared to provide more accurate orbital geometry reconstruction than PDS 0.5 mm, although no significant difference in reconstructive accuracy between PDS 0.25 mm and PDS 0.5 mm was observed in this cadaveric study.

OBJECTIVE: To determine the 30-day postoperative emergency room (ER) visit rate following ambulatory orbital fracture repair with same-day discharge, and the causes and risk factors associated with ER visit.
METHODS: Database study.
METHODS: State Ambulatory Surgery and Services Database (SASD) and State Emergency Department Database (SEDD) for California, New York, and Florida for 2011.
METHODS: We identified orbital fracture repair procedures among adults from the SASD, which was linked to the SEDD to identify the incidence and causes of ER visits within 30 days. Univariate and multivariable logistic regression models were used to determine the factors associated with ER visit.
RESULTS: Among 762 patients, the 30-day postoperative ER visit rate was 4.5%. Most ER visits (58.9%) occurred during the first week after surgery. The most common reasons for ER visits were related to pain, swelling, headache, dizziness, and fatigue (29.4%), followed by ophthalmologic etiologies including visual disturbances and infection of the eye (14.7%). There was no case of retrobulbar hematoma. In the multivariate analysis, patients living in Florida were at a significantly higher risk for ER visit compared to those in California (odds ratio: 4.48 [1.43-14.10], p = .010).
CONCLUSIONS: Ambulatory orbital fracture repair appears to be safe. Common reasons for ER visit included pain, swelling, and ophthalmic symptoms. An increased risk for ER visit was seen with certain geographic regions but not with medical comorbidities or concurrent facial fractures or procedures.

This first part of a two-part study examines perceived applications for and barriers to using printed titanium in light of current caseloads, funding pathways, and use of digital planning. It aims to demonstrate the scope for printed titanium in modern practice and to guide industry about the needs of UK surgeons. A cross-sectional study over 14 weeks was performed electronically with support from the British Association of Oral and Maxillofacial Surgeons (BAOMS) and a national trainee-led recruitment team. Ethics approval was obtained at the lead centre. A total of 132 participants joined the study (70% consultants, 25% specialty registrars, and 5% other), approximating a 29% response rate from consultant/registrar BAOMS members throughout mainland UK. Eighty-eight per cent used CAD-CAM design, with highly variable funding/access, design/manufacturing workflows (in-house/outsourced). Eighty-eight per cent were involved with trauma, 61% with orthognathic, and 52% with oncology-reconstruction surgery. Favourite applications for printed titanium were orbital floor repair (89%) and free-flap jaw reconstruction (87%). Most participants also cited maxillary/zygomatic osteotomies and cranioplasty (range 61%-73%). Although a popular application (78%), the evidence base in temporomandibular joint surgery is limited. Those performing orthognathic surgery perceived more indications than those who did not (p=0.013). Key barriers included cost, turnaround time and logistics, and the need to be trained in traditional techniques. Printed titanium was useful for both common and niche procedures, but was specifically limited in emergency trauma. Most surgeons had experience in CAD-CAM surgery but technical understanding appeared unclear. Limiting factors included variable funding and production pathways, perceived costs, and logistics, but in-house design can minimise them. In part II, we quantify perceived benefits and limitations and whether surgeons\' understanding and knowledge are sufficient to rationalise them.

Composite materials of photo-crosslinked poly(trimethylene carbonate) and nanoscale hydroxyapatite were prepared and their mechanical characteristics for application as orbital floor implants were assessed. The composites were prepared by solvent casting poly(trimethylene carbonate) macromers with varying amounts of nano-hydroxyapatite and subsequent photo-crosslinking. The incorporation of the nano-hydroxyapatite into the composites was examined by thermogravimetric analysis, scanning electron microscopy and gel content measurements. The mechanical properties were investigated by tensile testing and trouser tearing experiments. Our results show that nano-hydroxyapatite particles can readily be incorporated into photo-crosslinked poly(trimethylene carbonate) networks. Compared to the networks without nano-hydroxyapatite, incorporation of 36.3 wt.% of the apatite resulted in an increase of the E modulus, yield strength and tensile strength from 2.2 MPa to 51 MPa, 0.5 to 1.4 N/mm2 and from 1.3 to 3.9 N/mm2, respectively. We found that composites containing 12.4 wt.% nano-hydroxyapatite had the highest values of strain at break, toughness and average tear propagation strength (376% , 777 N/mm2 and 3.1 N/mm2, respectively).