Scientific Abstract Presentations: Craniomaxillofacial 10 Sunday, October 29 Sun, Oct 29 2:30-3:30 p.m. CDT

Introduction: Premature fusion is termed sagittal craniosynostosis (SC) and is described by a classic dysmorphology, scaphocephaly. Scaphocephaly results as bi-parietal expansion is inhibited and anterior and posterior compensatory elongation occurs. We recently used surface imaging modalities to develop regional measures quantifying elongation in the frontal bossing index (FBI) and occipital bullet index (OBI). Creating a width based measure, would allow the isolated measurement of the fundamental pathology of scaphocephaly. Further, it would allow for the creation of a global metric which could easily replace the familiar cephalic index. This combined system would allow surgeons to identify both global and regional morphology in scaphocephaly.

Methods: Surface imaging from CT scans or 3D photographs of 360 individuals with sagittal craniosynostosis and 221 normocephalic individuals was obtained. Cartesian grids were created on each individual's surface mesh using equidistant sagittal and coronal planes. Grid intersections were used as reproducible landmarks to identify patterns in width restriction. Area under the curve (AUC) analyses was performed to identify trends in regional morphology and create measures capturing population differences. The most distinct was then used to create a vertex narrowing index (VNI). Using the FBI, OBI, and VNI, a measure of W/L analogous to the cephalic index was created (Scaphocephalic Index, SCI). Measure performance was evaluated using area under the curve (AUC) analyses. Finally, measurement was then automated.

Results: With regard to width, control crania were observed to round while those with SC consistently slope inward, with a more triangular appearance. Population differences increased as more superior regions were evaluated, with difference peaking just posterior to the AP midline at a height 70% of the way between the tragion and vertex. The VNI performed well with an AUC of 0.97, a sensitivity of 91.2% and a specificity of 92.2%. Index score is independent of age (<5 years), sex, and imaging modality. The measures can be simply combined to form a SCI. SCI measure performance was nearly perfect (AUC >0.999, Sensitivity >99%, Specificity >99%) in distinguishing control vs SC patients. The population means were 63(±5) and 88(±5) for the SC and control populations respectively.

Conclusion: The VNI allows surgeons to measure and track the primary pathology of SC. Allowing for the isolated measurement of the width abnormality of sagittal craniosynostosis, vertex narrowing. The VNI in combination with the FBI and OBI create regional cranial shape indices which allow for superior differentiation of SC and control patients compared with other systems as it approaches the accuracy of CT imaging. The system may be further utilized for comparison of operative techniques for SC over time as it avoids the need for serial radiation for long-term shape evaluation and is automatable without prohibitive technologic requirements.

INTRODUCTION: In light of the increasing use of standing electric scooters on a nationwide scale, no study has specifically evaluated craniofacial injuries associated with their use to date.1-3 This study explored the incidence, demographics, and craniofacial injuries of standing e-scooter-related trauma in the United States over the past decade.

METHODS: The U.S. Consumer Product Safety Commission's National Electronic Injury Surveillance System (NEISS) was queried for trends in craniofacial, standing e-scooter injuries between 2012 and 2021. Data collected included patient demographics, injury diagnoses, use of alcohol and helmet, and disposition. The NEISS weight variable was used to calculate the estimated national incidence of these factors. Cases involving, mobility scooters, gasoline-powered scooters, mopeds, electric skateboards, or non-rider pedestrians were excluded.

RESULTS: 1193 patients resulted for treatment of standing, e-scooter-related craniofacial injuries at hospitals in the United States between 2012 and 2021, representing a 12.4-fold increase in cases over this decade. Patients were predominately male (65.5%) with ages ranging from 2 to 87 years (average 28.3 years). The most common craniofacial injuries were lacerations (30.91%), contusions or abrasions (17.39%), and concussions (14.44%). Of the head and neck injuries, lacerations most often occurred on the face (70.04%) while fractures most commonly affected the face (75.86%) and head (16.67%). The majority of patients were discharged home or observed in the emergency department (91.26%) with the remainder being admitted to the hospital (8.74%). Of patients 21 years or older, 22.87% were injured under the influence of alcohol. Helmet usage was specified in 5.69% and not found to affect concussions (OR: 1.48 95% CI [0.85,2.11]).

CONCLUSION: The increasing frequency of craniofacial injuries involving standing e-scooters, alongside the expansion of e-scooter ridesharing services in the United States, suggests the continued evaluation of e-scooter injury patterns. This cross-sectional study describes the frequency, type, and distribution of these craniofacial injuries and explores trends regarding alcohol and helmet use, injury diagnosis, and disposition. This knowledge can guide management and possibly inform prevention strategies. Additional studies should investigate the severity of these injuries and correlate results with other databases that explore hospital course.

1 Shichman, I., Shaked, O., Factor, S., Weiss-Meilik, A., & Khoury, A. (2022). Emergency department electric scooter injuries after the introduction of shared e-scooter services: A retrospective review of 3,331 cases. World J Emerg Med, 13(1), 5-10. doi:10.5847/wjem.j.1920-8642.2022.002 2 Toofany, M., Mohsenian, S., Shum, L. K., Chan, H., & Brubacher, J. R. (2021). Injury patterns and circumstances associated with electric scooter collisions: a scoping review. Injury Prevention, 27(5), 490. doi:10.1136/injuryprev-2020-044085 3 Commission, U. C. P. S. (2021). Injuries Using E-Scooters, E-Bikes and Hoverboards Jump 70% During the Past Four Years. Retrieved 12/2022. Retrieved from https://www.cpsc.gov/Newsroom/News-Releases/2021/Injuries-Using-E-Scooters-E-Bikes-and-Hoverboards-Jump-70-During-the-Past-Four-Years

Background: Pierre Robin Sequence (PRS) presents as isolated PRS [iPRS] or in conjunction with a genetic syndrome [sPRS] that subsequently leads to feeding difficulties, respiratory dysfunction, and eventual failure to thrive. Mandibular distraction osteogenesis (MDO) has remained a mainstay of treatment to directly address the tongue-based airway obstruction in PRS patients. sPRS patients routinely have a more challenging clinical course, and there is a paucity of data comparing the effectiveness of MDO as a treatment for sPRS versus iPRS.

Methods: A single-institution, IRB-approved, retrospective review was conducted of all PRS patients who underwent MDO by a single surgeon between January 2015-February 2022. The patients were stratified into iPRS or sPRS based on genetic evaluation (N=50) with 36% classified as sPRS. Primary measures were demographic and situational data including length of stay, follow-up, and complications; airway outcome measures included avoidance of tracheostomy, Apnea-Hypoxia Index (AHI), and laryngeal view pre-distraction and at the time of distractor removal.

Results: Prior to distraction, patient characteristics of the iPRS (N=32) and sPRS group (N=18) showed no significant differences in patient age (105.1 ± 199.7 days; range 2-1051 days), AHI (17.3 ± 17.1; range 3.6-90), or laryngeal view (65% grade III or IV) (p>0.05). Six months post-distractor removal, 92% of both sPRS and iPRS avoided tracheostomy (p>0.05). Overall, post-MDO, there was a statistically significant decrease in mean AHI from 17.3 to 4.5 (p<0.001). sPRS patients in particular had a significant decrease in average AHI following MDO from 15.2 to 4.5 (p=0.028). Post-MDO, both groups had similar improvement of laryngeal view, growth curve, and avoidance of g-tube (p>0.05).

Conclusions: Despite the fact that sPRS patients typically have a more challenging clinical course, we found an equivalent clinical improvement in AHI and laryngeal view between sPRS and iPRS patients post-MDO. In our experience, MDO can effectively treat the functional limitations that arise in PRS, and we found significant benefit to MDO in both iPRS and sPRS patients without one subtype being favored. However, the decision to move forward with distraction remains a nuanced one and should be individualized to each patient and family.

Background: In the management of patients with craniomaxillofacial deformities, it is imperative to understand normal anthropometric growth of the cranium. Although there have been advances in three-dimensional (3D) computed tomography (CT) images, there is an absence of normative growth curves of intracranial volume (ICV) and cranial index (CI) in a diverse population of healthy children using current imaging technology. The goal of this study is to establish normative craniometric growth curves in a healthy population of children (ages 0-18 years).

Methods: CT scans of 115 patients who underwent cranial imaging at a tertiary children's hospital were included. Patients with head trauma, hydrocephalus or pathologic cranial dysmorphology (plagiocephaly/craniosynostosis) were excluded. Patients were stratified into 23 age groups of 5 patients each (0-2 months, 3-5 months, 6-8 months, 9-11 months, 12-17 months, 18-23 months, and yearly from 2-18 years). Primary outcomes of total intracranial volume and cranial index were analyzed using CT scans. Primary outcomes were plotted across age intervals, along with best-fit logarithmic curves.

Results: Cranial index ranged from 75.44 to 83.55 in our cohort overall. The mean cranial index was 80.28 at birth, peaked to 83.55 at the 6–8 month period, and then returned to 80.96 at 3 years of age. The cranial index then continued to slowly decrease over time, reaching a nadir at age 18 years. In contrast, intracranial volume rapidly increased in the first 6-8 months of life, and then continued to slowly increase at each age interval throughout childhood, adolescence and into early adulthood.

Conclusion: Establishing normal cranial volumetric growth curves and changes in cranial indices during development is important in contextualizing cranial pathology. These data will enable us to compare pathologic cranial morphology, like craniosynostosis, to established normative growth curves.

INTRODUCTION Syndrome of the Trephined (SoT), or "sinking flap syndrome" refers to the neurological deterioration that occurs after a large craniectomy. This syndrome has various symptoms including headaches, worsened hemisyndrome, or cognitive disorders with or without an orthostatic component; that improve or resolve entirely as early as 3 to 4 days after a cranioplasty procedure. Previous studies have proposed that SoT may be underdiagnosed because it is often difficult to discern SoT from the congruent neurological insults present in these patients. Thus, this study aims to evaluate the frequency of SoT symptomatology in patients undergoing cranioplasty using Activity Measure for Post-Acute Care (AM-PAC) scores which is a validated, physical therapist-administered metric of patient basic mobility and activity. Further, this study aims to evaluate risk factors associated with the development of SoT.

METHODS A retrospective chart review was performed on 113 patients undergoing 172 cranioplasties between April 2016 to January 2022. Pertinent demographic, initial insult for craniectomy, cranial deficient size and surgical data was extracted from patients' charts. AM-PAC scores below 17 indicates >50% of impairments and a score of 24 implies no impairment. SoT was defined as ≥2 points of improvement in AM-PAC score 3-7 days after cranioplasty. If a patient met the criteria for SoT charts were investigated for the mention or diagnosis of SoT. Paired sample t-test and ANOVA was used to determine statistical significance.

RESULTS
Sixty-four patients (females; n=27, males; n=37) were seen by a physical therapist before and after their cranioplasty procedure and had their mobility/activitiy evaluated by AM-PAC scoring. The average pre-cranioplasty AM-PAC score was 11 and the average post-cranioplasty AM-PAC score was 13. Twenty-four patients met the criteria for SoT with an average improvement in AM-PAC score of 4.5 points (11.75 to 16.25 p=0.0125). The most significant improvement in scores occurred within 3.6 days (p=0.031). The major indication for the acquired cranial defect was decompressive craniectomy due to a large vessel stroke (n=26) followed by decompressive craniectomy due to a traumatic brain injury (n=12). There was no significant difference between the indication for the cranial defect and the development of SoT (p=0.4151). Although patients who met the criteria for SoT had larger cranial defects this was not significant (119.23cm^3 vs. 137.16cm^3 p=0.333). Notably, only three patients were diagnosed with SoT by a plastic surgeon.

CONCLUSION These results suggest an underdiagnosis of SoT in patients with large-size skull defects. It is important for surgeons to be astute in recognizing and diagnosing SoT since earlier cranioplasty may be warranted for these patients. It is crucial that we utilize of multidisciplinary approach including Plastic Surgeons, Neurosurgeons, Physical therapists and other medical professionals to prevent the worsening of SoT symptomatology towards improving patient outcomes.

Background: Effectiveness of continuous positive airway pressure (CPAP) in obstructive sleep apnea (OSA) may be compromised for patients who are intolerant of CPAP, have inadequate CPAP fit, or possess upper airway abnormalities.1 In these patients, maxillomandibular advancement (MMA) is a powerful surgical option. Kent et al2 demonstrated interventions like MMA resulted in significant changes in OSA outcomes such as reduction in apnea-hypopnea index (AHI) and respiratory disturbance index (RDI). However, there are no clear guidelines on how much advancement to perform to adequately treat OSA beyond anecdote. We conducted a systematic review to evaluate the amount of improvement on polysomnography outcomes following MMA and to correlate morphological adjustments to changes in OSA severity.     Method: Pubmed and Embase were our search engines for this PRISMA-compliant systematic review.3 Inclusion criteria were English-language studies that examined adult patients before and after isolated MMA for OSA. Studies were excluded if patients had syndromic diagnoses, previous history of jaw surgery, or combined surgical interventions for OSA treatment.  Two researchers independently reviewed each of these studies by first screening titles and abstracts. All remaining articles were subjected to full-text review by the same reviewers. Study variables included study design, location, year, and sample size. Patient variables included age, BMI, comorbidities, history of other OSA interventions, as well as pre- and post-treatment OSA assessment. Intervention variables included degree of mandibular and maxillary advancement as well as length of follow up.
  Results: 5904 titles were identified from initial search and 39 full-text articles were included evaluating a total of 898 patients. We found a significant reduction in AHI and RDI following MMA (46.1 to 9.5, and 42.7 to 6.5, respectively; p<0.05). The mean improvement in AHI was 36.59 ±17.27 and mean improvement in RDI was 36.17 ±23.00. MMA also led to significant increases in airway volume (11.0mL vs 17.6mL, p<0.001) and airway length (12.4mm vs 18.2mm, p<0.001). Overall, 22 studies reported an average mandibular advancement of 9.3 ±2.7 mm and 21 studies reported an average maxillary advancement of 7.8 ± 2.2 mm. Meta-regression analysis did not yield a correlation between the amount of improvement in AHI/RDI and jaw advancement.
  Conclusion: MMA is an effective treatment for patients with OSA, leading to significant improvements in polysomnography outcomes. There does not appear to be a clear correlation between the amount of advancement and degree of improvement in OSA, at least at the level of measuring study-level mean data.

References:

1. Kent D, Stanley J, Aurora RN, et al. Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2021;17(12):2499-2505. doi:10.5664/jcsm.9592

2. Kent D, Stanley J, Aurora RN, et al. Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2021;17(12):2507-2531. doi:10.5664/jcsm.9594

3. Page MJ, Moher D, Bossuyt PM, et al. PRISMA 2020 explanation and elaboration: updated guidance and exemplars for reporting systematic reviews. BMJ. 2021;372:n160. Published 2021 Mar 29. doi:10.1136/bmj.n160

Objective: It has been debated whether stripping the masticatory muscles during a bilateral sagittal split osteotomy (BSSO) causes significant resorption of the inferior mandibular border, leading to unfavorable aesthetic changes. The aim of this study is to assess the level of resorption of the mandible and the resulting aesthetic changes following BSSO with complete stripping.

Method: Pre-operative, 4-8 week post-operative, and minimum 6 month post-operative cone beam CT scans were obtained for 29 patients who underwent BSSO (27 advancement, 31 setback). All patients had complete stripping of the pterygomasseteric sling intraoperatively. 27 linear, angular and volumetric measurements were performed on scans using Mimics 24.0 (Materialise NV, Lueven, Belgium). Paired and unpaired t-test were performed to determine differences in measurements at the late postoperative time point.

Results: Mean advancement was 2.67mm and setback was -2.47mm with no significant amount of mean relapse. Antegonial notch height did not change significantly regardless of movement amount or direction. The mandibular body height decreased significantly with a mean change of -2.06mm ± 2.71 for advancements (p=0.002) and -2.11mm ± 2.92 for setbacks (p=0.004) in the late post-operative period. Additionally, the mandibular ramus had a significant loss in height with a mean change of -2.25mm ± 3.17 for advancements (p<0.001) and -1.63mm ± 3.61 for setback (p<0.05). The mandibular angle volume significantly increased with a mean change of 426.69mm3 ± 690.48 for advancements (p=0.004) and 476.08mm3 ± 1059.48 for setbacks (p=0.018) in the late post-operative period.

Thirty-one patients had a clockwise rotation of the proximal mandible and 27 had a counterclockwise rotation with a mean rotation of 3.65deg ± 1.86 and -3.72deg ± 3.19, respectively. The antegonial notch height did not significantly change. The mandibular body height significantly decreased for the clockwise group with a mean change of -1.56mm ± 2.79 (p<0.005) and increased for the counterclockwise group with a mean change of 2.69mm ± 2.74 (p<0.001). The mandibular ramus height significantly decreased for the counterclockwise group with a mean change of -3.02mm ± 2.96 (p<0.05). The mandibular angle volume significantly increased with a mean change of 226.14mm3 ± 605.01 for the clockwise group (p<0.05) and 713.65mm3 ± 1104.09 for the counterclockwise group (p=0.002).

There was a significant soft tissue difference at the antegonial notch between the setback and advancement groups with a greater change occurring in the setback group from the coronal and axial views. In the coronal view, the antegonial notch height difference was 1.81mm ± 1.38 for the advancement group and 3.25mm ± 2.09 for the setback group (p=0.005). In the axial view, the antegonial notch height difference was 1.88mm ± 1.80 for the advancement group and 3.69mm ± 2.44 for the setback group (p=0.002). However, a regression analysis performed on the soft tissue changes as they related to the hard tissue changes at the antegonial notch showed no correlation at the coronal view (R2=0.044) or axial view (R2=0.018).

Conclusion: While changes to the mandibular contour do occur after BSSO, these changes do not appear to be large enough to be aesthetically significant. Complete stripping of the pterygomasseteric sling appears to be a safe maneuver if needed.

PURPOSE: Single-stage bilateral cleft lip repair is frequently espoused as the gold standard for bilateral cleft lip repair procedures. Two-stage bilateral cleft lip repair is an alternative method that, while not as universally accepted, may result in acceptable functional and aesthetic long-term outcomes. We propose and provide long-term follow-up for a different approach to bilateral cleft lip repair following the principles used for the unilateral cleft deformity. Although the downside of this surgical technique is that it involves an additional operation, in the long-term it may be an acceptable alternative to one-stage repairs.

METHODS: This is a 16-year retrospective review of all patients that underwent two-stage repair for complete bilateral cleft lip deformity, performed by a single surgeon (S.A.W). Patients meeting inclusion criteria were in mixed dentition and were treated with the following protocol: (1) Pre-surgical naso-alveolar molding and approximation of alveolar segments, (2) Staged rotation advancements with gingivosupraperiosteoplasty and closure of alveolar defect extending back to closure of the anterior palate, (3) McComb nasal correction, (4) Rotation advancement lip repair just as is done in a unilateral cleft, (5) Repetition of the procedure on the contralateral side after 3 months, (6) Closure of the remaining hard palate and soft palate with levator muscle retroposition at 18 months. Cephalometric and anthropometric evaluation at mixed dentition was conducted to evaluate midface growth. Mean Farkas anthropometric measurements for patients in our cohort were compared to mean values for non-cleft patients (nasolabial angle, cutaneous/total upper lip height and nasal tip protrusion/nose height). Mean cephalometric values (SNA, SNB, ANB) for our cohort were compared to values for non-cleft patients.

RESULTS: Thirty-two patients were identified via retrospective review who met inclusion criteria. There was no significant difference between anthropometric values for normal versus cleft lip and palate patients for nasolabial angle, cutaneous/total upper lip height, and nasal tip protrusion/nose height (p > 0.05). Anthropometric measurements fell within 1-2 standard deviations of the norm. Cephalometric films were evaluated for 15 patients. Mean SNA was 78.9±4.3, SNB was 74.1±3.8, and ANB was 5.0±3.4, with no significant difference between SNA (80.0±3.7), SNB (74.0±3.4) and ANB (4.0±1.4) for non-cleft patients (p > 0.05).

CONCLUSION: Using the staged method, noses are normal with a normal nasolabial angle and a normal columella. Lips are full and pouting. There is no ventroflexion of the premaxilla. The results that can be obtained with the use of the staged rotation advancement procedure justify continuing its use. The long-term follow-up of this patient population has proven to have results that resemble the dimensions and ratios of the lip and nose of unaffected children.