The statistical shape model as a quality assurance measure in the treatment of complex midface fractures: a case control study

Background Complex bilateral midface fractures necessitate a surgically challenging procedure to preserve or restore the occlusion and the sensitive eye area. In this case control study, we aim to show the potential of a statistical shape model (SSM) for measuring the quality of the midface reconstruction, compared to the estimated preoperative situation. Methods An individualized SSM was postoperatively registered on 19 reconstructed complex bilateral midface fractures. Using this SSM, the distances from the simulated preoperative situation to the postoperative positions of the fracture segments were calculated. The fracture lines for Le Fort II, Le Fort III, and NOE fractures were chosen as reference points for the distance measurements. Results The SSM could be registered on all 19 complex bilateral midface fractures. All analyzed fractures showed a dorsal impaction (negative values) of the midface. Le Fort II fractures showed deviation values of –0.98 ± 4.6 mm, Le Fort III fractures showed values of –3.68 ± 3.6 mm, NOE type 2 fractures showed values of –0.25 ± 4.6 mm, and NOE type 1 fractures showed values of –0.25 ± 4.6 mm. Conclusions The SSM can be used to measure the quality of the achieved reduction of complex bilateral midface fractures based on the estimated preoperative situation. Trial registration DRKS00009719.

Le Fort III Distraction Osteogenesis: Early Experience With an Internal Bilevel Midface Distraction System

Internal distraction devices for severe midface hypoplasia are often criticized for their distraction at a single pivot point, resulting in “mid-face tipping,” a phenomenon which is in part related to the differential resistance of the soft tissues at orbital and maxillary levels. To address this deficiency, we present our early experience with an internal bi-level midface distraction system. Four patients underwent midface advancement with an internal bi-level distraction system. The specifics of design, application, distraction, and removal are detailed. Hospital records were reviewed to capture patient demographics, length of stay, OR times, and complications. Relevant cephalometry was performed pre- and post-operatively, and compared. In 2015, 4 patients with severe mid-face hypoplasia were treated with an internal bi-level mid-face distraction system. The mean age was 13.5 ± 1.7 years. The mean operative time was 269.7 ± 67.4 min. The mean LOS was 10 ± 7.4 days. The on-table distraction was 5 mm. Distraction subsequently proceeded at a variable rate of 0.5 to 1.0 mm daily with a maximal distraction of 20 and 30 mm at orbital and maxillary levels, respectively. Mean time to distractor removal was 11.2 ± 1.1 weeks. Device design allowed facile removal through minimally invasive incisions. Cephalometry was seen to progress towards age-matched norms. There were no major complications. Minor complications included breakage of the vertical component of the maxillary arm at the time of device removal in 1 patient. By allowing real-time adjustment at the orbital and maxillary levels to combat differential resistance, early experience with our device maximizes occlusal advancement without overcompensating orbital translation.

Craniofacial Corrective Surgery in Syndromic Craniosynostosis

This surgical field has now progressed and becoming an established subspecialty involving various surgical disciplines worldwide. Various complex CMF syndromes reported in syndromic craniosynostosis include Crouzon, Apert and Pfeiffer syndromes. These syndromes carry specific functional discrepancies associated with the affected structural anomaly and may therefore have functional issues involving the brain, eye and airway among others. As corrective surgery is often indicated depending on the affected vital functions, other factors that need to be considered are patient’s age, comorbidities, urgency, available expertise and patient’s overall prognosis based on the degree of anomaly. As such, the corrective surgery can be categorized into; (1) intermediate which is performed at an early phase and aimed to improve or salvage important vital functions such as the brain, eye, airway or feeding which are important for the child’s development and, (2) definitive treatment aimed at permanently correct the functional discrepancies. Intermediate corrective surgery may include invasive procedures such as ventriculo-peritoneal (VP) shunts, tarsorrhaphy, adenotonsillectomy and tracheostomy whereas definitive corrective surgery may include surgical procedures such as monobloc, Le Fort III osteotomy, posterior cranial vault expansion and mandibular advancement. This chapter will elaborate on the indications, types, challenges in the management and the proposed prevention measures in corrective surgery for specifically for syndromic craniosynostosis patients.