Xi Gong

Zygomatic Surface Marker-Assisted Surgical Navigation: A New Computer-Assisted Navigation Method for Accurate Treatment of Delayed Zygomatic Fractures

PURPOSE To describe a new method of zygomatic surface marker navigation to treat delayed unilateral zygomatic fractures. PATIENTS AND METHODS The computed tomography (CT) data for 6 patients were obtained before surgery and imported into the surgical planning software. After 3-dimensional (3D) construction and segmentation, 3D cylindrical-shaped objects in stereolithographic format were placed in position and merged with the data from the fractured segments to mark the area for surface reduction. Data from the unaffected side were used to guide the reduction data for the segments with markers. During surgery, the surface markers were marked by drilling holes in the fractured bones in a process guided by the surgical navigation plan established before osteotomy. The segments were then reduced to the predetermined places using the positions of the hole markers as guides. 3D image comparisons and axial CT measurements were used to evaluate navigation accuracy and bone symmetry. RESULTS Six patients with unilateral delayed zygomatic fractures were treated using this approach. The mean deviation between the postoperative 3D images and the reduction navigation plan for the 6 patients was +1.24 mm and -1.4 mm. The mean width deviation between the affected and unaffected sides was 1.28 mm, and the mean eminence deviation was 1.22 mm. All patients were followed up for at least 3 months and experienced no obvious complications. CONCLUSIONS Zygomatic surface marker-assisted surgical navigation can simplify the navigation planning for surgery and avoid the complex protocols needed to create the surgical templates. The navigation accuracy was acceptable, and all 6 patients obtained good facial symmetry.

Risk Factors for Life-Threatening Complications of Maxillofacial Space Infection.

AbstractThe purpose of this study was to review the clinical features of maxillofacial space infection (MSI), and to identify the potential risk factors predisposing to life-threatening complications. A retrospective review of the medical charts of patients with MSI treated at Peking University School and Hospital of Stomatology from August 2008 to September 2013 was conducted. A total of 127 patients [75 men (59.1%) and 52 women (40.9%); mean age, 45.39 ± 21.18 years, with a range of 1–85 years] formed the study cohort. The most common cause of MSI was odontogenic infection (57.5%). The most common space involved was the submandibular space. All patients were treated by antibiotics as well as surgical incision and drainage. Sixteen patients developed life-threatening complications, and the dominant complication was respiratory obstruction. Multivariate logistic regression analysis revealed the percentage of neutrophils (NEUT%) upon hospital admission ≥85.0% to be associated with life-threatening complications (P < 0.05). Even though adequate antibiotic therapy and incision and drainage of abscess were given, MSI patients with NEUT% upon hospital admission ≥85.0% carry a higher risk of life-threatening complications. In these patients, an aggressive treatment strategy is mandatory.

Comparative Study of Four Maxillofacial Trauma Scoring Systems and Expert Score

PURPOSE To select a scoring system suitable for the scoring of maxillofacial trauma by comparing 4 commonly used scoring systems according to expert scoring. PATIENTS AND METHODS Twenty-eight subjects who had experienced maxillofacial trauma constituted the study cohort. Four commonly used systems were selected: New Injury Severity Score (NISS), Facial Injury Severity Scale (FISS), Maxillofacial Injury Severity Score (MFISS), and Maxillofacial Injury Severity Score (MISS). Each patient was graded using these 4 systems. From the experience of our trauma center, an expert scoring table was created. After the purpose and scheme of the study had been explained, 35 experts in maxillofacial surgery were invited to grade the injury of the 28 patients using the expert scoring table according to their clinical experience. The results of the 4 scoring systems and expert score were compared. RESULTS The results of the 4 scoring systems and expert score demonstrated a normal distribution. All results demonstrated significant differences (P < .01). The Pearson correlation coefficient between the MFISS and expert score was the greatest (0.801). The correlation coefficient between the NISS, FISS, and MISS and the expert score was 0.714, 0.699, and 0.729, respectively. Agreement between the standardized scores and the expert score was evaluated using Bland-Altman plots; the agreement between the standardized MFISS and expert score was the best. CONCLUSIONS Compared with the other 3 scoring systems, the correlation and agreement between the MFISS and expert score was greater. This finding suggests that the MFISS is more suitable for scoring maxillofacial injuries.