Faculty Bibliography

BACKGROUND:Nerve regeneration after an injury should occur in a timely fashion for function to be restored. Current methods cannot monitor regeneration prior to muscle reinnervation. Diffusion tensor imaging has been previously shown to provide quantitative indices after nerve recovery. The goal of this study was to validate the use of this technology following nerve injury via a series of rat sciatic nerve injury/repair studies. METHODS:Sprague-Dawley rats were prospectively divided by procedure (sham, crush, or cut/repair) and time points (1, 2, 4, and 12 weeks after surgery). At the appropriate time point, each animal was euthanized and the sciatic nerve was harvested and fixed. Data were obtained using a 7-Tesla magnetic resonance imaging system. For validation, findings were compared to behavioral testing (foot fault asymmetry and sciatic function index) and cross-sectional axonal counting of toluidine blue-stained sections examined under light microscopy. RESULTS:Sixty-three rats were divided into three treatment groups (sham, n = 21; crush, n = 23; and cut/repair, n = 19). Fractional anisotropy was able to differentiate between recovery following sham, crush, and cut/repair injuries as early as 2 weeks (p < 0.05), with more accurate differentiation thereafter. More importantly, the difference in anisotropy between distal and proximal regions recognized animals with successful and failed recoveries according to behavioral analysis, especially at 12 weeks. In addition, diffusion tension imaging-based tractography provided a visual representation of nerve continuity in all treatment groups. CONCLUSIONS:Diffuse tensor imaging is an objective and noninvasive tool for monitoring nerve regeneration. Its use could facilitate earlier detection of failed repairs to potentially help improve outcomes.

Osteocutaneous reconstruction can be challenging because of concomitant injuries and limited donor sites. There is a paucity of data on limb salvage outcomes following combined soft-tissue reconstruction and bone transport or Masquelet procedures. The authors reviewed a consecutive series of open tibia fracture patients undergoing soft-tissue reconstruction with either distraction osteogenesis or Masquelet technique. Endpoints were perioperative flap complications and bone union. Fourteen patients with Gustilo type IIIB open tibia fractures were included. Half of the group received muscle flaps and the remaining half received fasciocutaneous flaps. Ten patients (71.4 percent) underwent distraction osteogenesis and the remaining patients underwent Masquelet technique. Average bone gap length was 65.7 ± 31.3 mm (range, 20 to 120 mm). In the bone transport group, the average external fixation duration was 245 days (range, 47 to 686 days). In the Masquelet group, the average duration of the first stage of this two-stage procedure (i.e., time from cement spacer placement to bone grafting) was 95 days (range, 42 to 181 days). Bone union rate, as determined by radiographic evidence, was 85.7 percent. There was one complete flap failure (7.1 percent). One patient underwent below-knee amputation after failing bone transport and developing chronic osteomyelitis and subsequent infected nonunion. Our case series demonstrates that nonosteocutaneous flap methods of limb reconstruction are a viable option in patients with segmental long bone defects, with a bone union rate of 85 percent and a limb salvage rate over 90 percent in patients with Gustilo type IIIB fractures. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.

Pierre Robin sequence is the constellation of micrognathia, glossoptosis, and tongue-based airway obstruction. When airway obstruction is severe, feeding, growth, and respiratory demise are at risk. Neonatal mandibular distraction osteogenesis is a technique which improves tongue-based airway obstruction and avoids tracheostomy in patients with severe expressions of Pierre Robin sequence. Its efficacy in relieving airway obstruction is well documented, and it has become the surgical intervention of choice at many craniofacial centers. However, this is an uncommon procedure which can be performed within the first weeks of life, offering little space for a learning curve. The success of neonatal distraction and avoidance of complications is highly dependent on proper surgical technique. This report provides a brief overview of the disease, details the technique of the senior surgeon with captioned videos, describes the protocol used at our institution and reports long-term outcomes with a case description.

BACKGROUND:We describe the technique of robotic vaginectomy, anterior vaginal flap urethroplasty, and use of a longitudinally split pedicled gracilis muscle flap to recreate the bulbar urethra and help fill the vaginal defect in female-to-male gender affirming phalloplasty. METHODS:Vaginectomy is performed via robotic assisted laparoscopic transabdominal approach. Concurrently, gracilis muscle is harvested and passed through a tunnel between the groin and vaginal cavity. It is then split longitudinally and the inferior half is passed into the vaginal cavity, where it is inset into the vaginal cavity. Following urethroplasty, the superior half of the gracilis flap is placed around the vaginal flap to buttress this suture line with well-vascularized tissue. RESULTS:From May 2016 to March 2018, 16 patients underwent this procedure, of average age 35.1 ± 8.8 years, BMI 31.4 ± 5.5, and ASA class 1.8 ± 0.6. The average length of operation was 423.6 ± 84.6 minutes, with an estimated blood loss of 246.9 ± 84.9 mL. Patients were generally out of bed on post-operative day 1, ambulating on post-operative day 2, and discharged home on post-operative day 3 (average day of discharge 3.4 ± 1.4 days). At mean follow-up time of 361.1 ± 175.5 days, no patients developed urinary fistula at the urethroplasty site. CONCLUSIONS:Our use of the longitudinally split gracilis muscle in first stage phalloplasty represents a novel approach to providing well-vascularized tissue to achieve both urethral support and closure of intra-pelvic dead space, with a single flap, in a safe, efficient, and reproducible manner.

BACKGROUND:The authors present an institutional experience treating congenital and acquired temporomandibular joint (TMJ) ankylosis, detailing outcomes and potential risk factors of recurrence. METHODS:Retrospective chart review identified patients with TMJ ankylosis (1976-2019). Clinical records, operative reports, and imaging studies were reviewed for demographics, surgical operations, and ankylosis including maximal interincisal opening (MIO) and re-ankylosis. RESULTS:Forty-four TMJs with bony ankylosis were identified in 28 patients (mean age at any initial mandibular surgery: 3.7; range:0-14 years). Follow-up was 13.7 ± 5.9 years. Sixteen (57.1%) patients had bilateral ankylosis; 27(96.4%) had syndromes. Nine patients had congenital ankylosis, 16 had iatrogenic ankylosis (4.5 ± 3.7 years from initial distraction osteogenesis or autologous mandibular reconstruction) referred from outside institutions in 6 instances, and 3 had post-infectious ankylosis. Patients having their first mandibular operation at a younger age had more frequent reoperations for recurrent TMJ ankylosis, although this did not reach statistical significance. Mean improvement in MIO was 21.4 ± 7.3 mm. Ankylosis recurred in 21 (75%) patients. Five patients with congenital TMJ ankylosis required gastrostomy and remained at least partially dependent. Five patients had tracheostomy at the time of TMJ ankylosis surgery: 2 were eventually decannulated and 3 required repeat tracheostomy after ankylosis recurrence and remained tracheostomy-dependent. CONCLUSION/CONCLUSIONS:The clinical course of TMJ ankylosis in children affected by craniofacial differences is complex and typically involves a high rate of recurrence and multiple reoperations despite initial improvement in postoperative MIO. Younger age at initial mandibular surgery and number of operations require further investigation as potential predictors of recurrent TMJ ankylosis as well as tracheostomy and gastrostomy dependence.

PURPOSE/OBJECTIVE:To synthesize a zirconia-toughened alumina (ZTA) composite with 85% alumina matrix reinforced by 15% zirconia and to characterize its optical and mechanical properties before and after artificial aging, to be compared with a conventional dental zirconia (3Y-TZP). MATERIAL AND METHODS/METHODS:After syntheses, ZTA and 3Y-TZP powders were uniaxially and isostatically pressed. Green-body samples were sintered and polished to obtain 80 disc-shaped specimens per group (12 × 1 mm, ISO 6872:2015). The crystalline content and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Optical properties were determined by the calculation of contrast ratio (CR) and translucency parameter (TP) using reflectance data. Mechanical properties were assessed by Vickers hardness, fracture toughness and biaxial flexural strength test (BFS). All analyses were conducted before and after artificial aging (20h, 134 °C, 0.22 MPa). Optical parameters and microhardness differences were evaluated through repeated-measures analysis of variance (p < 0.05). BFS data were analyzed using Weibull statistics (95% CI). RESULTS:The synthesis of the experimental ZTA composite was successful, with 98% of theoretical density, as shown in the SEM images. XRD patterns revealed typical zirconia and alumina crystalline phases. ZTA optical properties parameters showed no effect of aging, with a high CR and low TP values denoting a high masking-ability. 3Y-TZP presented lower masking-ability and aging significantly affected its optical properties. ZTA Vickers hardness, fracture toughness and Weibull parameters, including characteristic stress and Weibull modulus were not influenced by aging, while 3Y-TZP presented a significant decrease in characteristic stress and increase in fracture toughness after aging. The ZTA probability of survival for missions of 300 and 500 MPa was estimated at ~99% validating its use for 3-unit posterior fixed dental prostheses (FDP), and no different from conventional 3Y-TZP. At high-stress mission (800 MPa) a significant decrease in probability of survival was observed for aged 3Y-TZP (84%) and for immediate and aged ZTA (73 and 82% respectively). CONCLUSION/CONCLUSIONS:The ZTA composite presented a dense microstructure, with preservation of the crystalline content, optical and mechanical properties after artificial aging, which encourages future research to validate its potential use for large span FDP.

OBJECTIVES/OBJECTIVE:To examine racial/ethnic differences in type of SSB most frequently consumed and in correlates of youth sugar-sweetened beverage (SSB) intake. METHODS:Data were obtained from the National Health and Nutrition Examination Survey (NHANES), 2011-2016, for children and adolescents aged 5-17 years (n = 6507). The main outcome was SSB consumption (i.e., sodas, sweetened fruit drinks, nectars, sports and energy drinks, sweetened coffees and teas, enhanced waters). Mean and proportions of SSB intake were estimated accounting for complex sampling strategy and weighting. Multivariable regression models were developed for each race/ethnicity and age group. RESULTS:Two-thirds of children and adolescents reported consuming SSB on a given day. Among consumers, mean SSB consumption was greatest for Black children and White adolescents and lowest for Asian American children and adolescents. The most popular type of SSB consumed was sweetened fruit drinks among children and soda among adolescents, except among White and Mexican American children for whom soda and Black adolescents for whom sweetened fruit drinks were most popular. Female sex and water intake were negatively associated with SSB consumption across most races/ethnicities. Screen time, dentist visits, nativity, and guardian education were associated with SSB intake among a subset of races/ethnicities. CONCLUSIONS:Associations between covariates and SSB intake as well as types of beverages preferred vary by race/ethnicity, as such chronic disease policies should not be 'one size fits all'. Targeted interventions for specific groups of vulnerable youths hold promise for further reducing SSB consumption, including directing efforts towards reducing sweetened fruit drinks for Black children.

BACKGROUND:Current Procedural Terminology (CPT) codes are an important part of surgical documentation and billing for services provided within the United States. This limited coding language presents a challenge in the heterogenous and rapidly evolving field of craniofacial surgery. The authors aimed to survey members of the American Society of Maxillofacial Surgery (ASMS) to characterize the variability in coding practices in the surgical management of craniofacial trauma. METHODS:A cross-sectional of 500 members of the ASMS survey was carried out. Descriptive statistics were calculated. The effect of various practice characteristics on coding practices was evaluated using Chi-squared tests and Fisher's exact tests. RESULTS:In total, 79 participants responded including 77 plastic surgeons. About 75% worked in academic centers and 38% reported being in practice over 20 years. Coding practices were not significantly associated with training background or years in practice. Unilateral mandibular and unilateral nasoorbitoethmoid fractures demonstrated the greatest agreement with 99% and 88% of respondents agree upon a single coding strategy, respectively. Midface fractures, bilateral nasoorbitoethmoid fractures, and more complex mandibular demonstrated considerable variability in coding. CONCLUSION/CONCLUSIONS:There is a wide variability among members of the ASMS in CPT coding practices for the operative management of craniofacial trauma. To more accurately convey the complexity of craniofacial trauma reconstruction to billers and insurance companies, the authors must develop a more descriptive coding language that captures the heterogeneity of patient presentation and surgical procedures.