Faculty Bibliography

Background/Purpose: For the past 25 years computer-based simulation of cleft lip repair has been an elusive goal. To date, interactive 3D models have allowed students to make preoperative incision markings. Animation generated blend shapes allow premodeled surgical animations to be played back in 3D video game format. Neither of these efforts allow the student to actually perform his/her own lip repair. This article presents what we believe to be the first cleft lip simulator to allow the student to prospectively do complete cleft lip/ nose corrections. Historical procedures and proposed new ones can be performed. A deeper level of understanding can be obtained using this cognitive experiential approach without injuring a real patient. Methods/Description: A 3D solid model of a complete unilateral cleft lip/nose has been prepared based on a laser scan of an actual patient. Procedures are performed using a surgical toolkit consisting of (1) skin hooks, (2) skin/mucosa scalpel, (3) skin and periosteal undermine tool, (4) deep cut tool for cutting through muscle, fat, and cartilage, and (5) a suture tool. First order biologically accurate physics are provided by modeling the solids as a half million tetrahedra. Projective dynamics are used to implement biphasic tissue behavior in which at low strain Hooke's law elasticity is provided, but as strain exceeds 14% the tissue becomes much stiffer to model the commonly observed the flap won't reach phenomenon. Collision is modeled between the teeth and bone of the maxilla and the undersurface of the lip using a Schur complement approach. Near real-time performance is provided on a laptop computer in 3D video game format. A history files may be recorded of the sequence of actions performed by the surgeon.
Result(s): A demonstration of the model and the surgical toolset will be performed in real time. A full cleft lip/nose repair using the simulator will be demonstrated using its history feature.
Conclusion(s): A first order biophysically accurate simulator of cleft lip and nose repair has been developed. It permits the student to cognitively explore different methods of repair and store his/her surgical sequence. This simulator has application in experiential education, proficiency testing, and the design of new surgical procedures

Pierre Robin sequence is defined by the clinical triad: mandibular hypoplasia, glossoptosis, and airway obstruction. Mandibular distraction osteogenesis (MDO) is a standard treatment of Robin sequence associated with severe airway obstruction and is the only intervention that directly corrects the underlying anatomic pathologic condition. Compared with tongue-lip adhesion, MDO has demonstrated more success in treating airway obstruction in infants with Pierre Robin sequence, including patients with syndromic diagnoses and concomitant anomalies. This article provides a current, comprehensive review of neonatal mandibular distraction and offers treatment guidelines based on a combined surgical experience of more than 400 patients.

The Le Fort III advancement was first described in 1950 and has since become a key technique in the armamentarium of craniofacial surgeons. The application of distraction osteogenesis to the craniofacial skeleton has allowed for large movements to be performed safely in young patients. This technique is valuable for correcting exorbitism, airway obstruction owing to midface retrusion, and class III malocclusion. It can be performed with either an external distractor or internal distractors. Although serious complications have been reported, these occur rarely when performed by experienced providers.

OBJECTIVE/UNASSIGNED:Utilize 3-dimensional (3D) photography to evaluate the nasolabial changes in infants with bilateral cleft lip and palate (BCLP) who underwent nasoalveolar molding (NAM) and primary reconstructive surgery. DESIGN/UNASSIGNED:coordinates to obtain the linear and angular measurements. Nasal form changes were measured and analyzed between T1 (0.5 months old), T2 (5 months old), and T3 (6 months old). Intraclass correlation coefficient was performed for intrarater reliability. Averaged data from the 3D images was statistically analyzed from T1 to T2 and T2 to T3 with Wilcoxon tests. Unaffected infant norms from the Farkas publication were used as a control sample. RESULTS/UNASSIGNED:After NAM therapy, statistically significant changes in the position of subnasale and labius superius improved nasolabial symmetry. Both retruded after NAM were displaced downward after NAM and surgical correction with respect to soft tissue nasion. The nasal tip's projection was maintained with NAM and surgical correction. The columella lengthened from 1.4 to 4.71 mm following NAM. CONCLUSIONS/UNASSIGNED:There was a significant improvement in the nasolabial anatomy after NAM, and this was further enhanced after primary reconstructive surgery.

STUDY OBJECTIVES/OBJECTIVE:Identifying optimal treatment for infants with Robin sequence (RS) is challenging due to substantial variability in the presentation of upper airway obstruction (UAO) in this population. Objective assessments of UAO and treatments are not standardized. A systematic review of objective measures of UAO was conducted as step towards evidence based clinical decision making for RS. METHODS:A literature search was performed in Pubmed and Embase databases (1990-2020) following PRISMA-guidelines. Articles reporting on RS and UAO-treatment were included if the following objective measures were studied: oximetry, polysomnography and blood gas. Quality was appraised by methodological index for non-randomized studies (MINORS, range:0-24). RESULTS:A total of 91 articles met inclusion criteria. Mean MINORS-score was 7.1 (range:3-14). Polysomnography was most frequently used (76%) followed by oximetry (20%) and blood gas (11%). Sleep position of the infant was reported in 35% of studies, with supine position most frequently, and monitoring time in 42%, including overnight recordings in more than half. Of 71 studies that evaluated UAO-interventions, the majority used polysomnography (90%), of which 61% did not specify the polysomnography technique. Reported polysomnography metrics included oxygen saturation (61%), apnea-hypopnea index (52%), carbon dioxide levels (31%), obstructive-apnea-hypopnea index (27%), and oxygen-desaturation-index (16%). Only 42 studies reported indications for UAO-intervention, with oximetry and polysomnography thresholds used equally (both 40%). In total, 34 distinct indications for treatment were identified. CONCLUSIONS:This systematic review demonstrates a lack of standardization, interpretation and reporting of assessment and treatment indications for UAO in RS. An international, multidisciplinary consensus protocol is needed to guide clinicians on optimal UAO assessment in RS.

BACKGROUND:The authors present outcomes analysis of the nasoalveolar molding treatment protocol in patients with a cleft followed from birth to facial maturity. METHODS:A single-institution retrospective review was conducted of cleft patients who underwent nasoalveolar molding between 1990 and 2000. Collected data included surgical and orthodontic outcomes and incidence of gingivoperiosteoplasty, alveolar bone grafting, surgery for velopharyngeal insufficiency, palatal fistula repair, orthognathic surgery, nose and/or lip revision, and facial growth. RESULTS:One hundred seven patients met inclusion criteria (69 with unilateral and 38 with bilateral cleft lip and palate). Eighty-five percent (91 of 107) underwent gingivoperiosteoplasty (unilateral: 78 percent, 54 of 69; bilateral: 97 percent, 37 of 38). Of those patients, 57 percent (52 of 91) did not require alveolar bone grafting (unilateral: 59 percent, 32 of 54; bilateral: 54 percent, 20 of 37). Twelve percent (13 of 107) of all study patients underwent revision surgery to the lip and/or nose before facial maturity (unilateral: 9 percent, six of 69; bilateral: 18 percent, seven of 38). Nineteen percent (20 of 107) did not require a revision surgery, alveolar bone grafting, or orthognathic surgery (unilateral: 20 percent, 14 of 69; bilateral: 16 percent, six of 38). Cephalometric analysis was performed on all patients with unilateral cleft lip and palate. No significant statistical difference was found in maxillary position or facial proportion. Average age at last follow-up was 20 years (range, 15 years 4 months to 26 years 10 months). CONCLUSIONS:Nasoalveolar molding demonstrates a low rate of soft-tissue revision and alveolar bone grafting, and a low number of total operations per patient from birth to facial maturity. Facial growth analysis at facial maturity in patients who underwent gingivoperiosteoplasty and nasoalveolar molding suggests that this proposal may not hinder midface growth. CLINICAL QUESTION/LEVEL OF EVIDENCE/METHODS:Therapeutic, IV.

OBJECTIVE/UNASSIGNED:This study evaluates skeletal and dental outcomes of LeFort I advancement surgery in patients with cleft lip and palate (CLP) with varying degrees of maxillary skeletal hypoplasia. DESIGN/UNASSIGNED:Retrospective study. METHOD/UNASSIGNED:: ≤-10 mm. PARTICIPANTS/UNASSIGNED:Fifty-one patients with nonsyndromic CLP with hypoplastic maxilla who met inclusion criteria. INTERVENTION/UNASSIGNED:LeFort I advancement. MAIN OUTCOME MEASURE/UNASSIGNED:Skeletal and dental stability post-LeFort I surgery at a 1-year follow-up. RESULTS/UNASSIGNED:At T2, LeFort I surgery produced an average correction of maxillary hypoplasia by 6.4 ± 0.6, 8.1 ± 0.4, and 10.7 ± 0.8 mm in the mild, moderate, and severe groups, respectively. There was a mean relapse of 1 to 1.5 mm observed in all groups. At T3, no statistically significant differences were observed between the surgical groups and controls at angle Sella, Nasion, A point (SNA), A point, Nasion, B point (ANB), and overjet outcome measures. CONCLUSIONS/UNASSIGNED:LeFort I advancement produces a stable correction in mild, moderate, and severe skeletal maxillary hypoplasia. Overcorrection is recommended in all patients with CLP to compensate for the expected postsurgical skeletal relapse.

The basic concepts from the fields of biology and engineering are integrated into tissue engineering to develop constructs for the repair of damaged and/or absent tissues, respectively. The field has grown substantially over the past two decades, with particular interest in bone tissue engineering (BTE). Clinically, there are circumstances in which the quantity of bone that is necessary to restore form and function either exceeds the patient's healing capacity or bone's intrinsic regenerative capabilities. Vascularized osseous or osteocutaneous free flaps are the standard of care with autologous bone remaining the gold standard, but is commonly associated with donor site morbidity, graft resorption, increased operating time, and cost. Regardless of the size of a craniofacial defect, from trauma, pathology, and osteonecrosis, surgeons and engineers involved with reconstruction need to consider the complex three-dimensional (3D) geometry of the defect and its relationship to local structures. Three-dimensional printing has garnered significant attention and presents opportunities to use craniofacial BTE as a technology that offers a personalized approach to bony reconstruction. Clinicians and engineers are able to work together to produce patient-specific space-maintaining scaffolds tailored to site-specific defects, which are osteogenic, osseoconductive, osseoinductive, encourage angiogenesis/vasculogenesis, and mechanically stable upon implantation to prevent immediate failure. In this work, we review biological and engineering principles important in applying 3D printing technology to BTE for craniofacial reconstruction as well as present recent translational advancements in 3D printed bioactive ceramic scaffold technology.