Faculty Bibliography

The calvaria (top part of the skull) is made of pieces of bone as well as multiple soft tissue joints called sutures. The latter is crucial to the growth and morphogenesis of the skull, and thus a loss of calvarial sutures can lead to severe congenital defects in humans. During embryogenesis, the calvaria develops from the cranial mesenchyme covering the brain, which contains cells originating from the neural crest and the mesoderm. While the mechanism that patterns the cranial mesenchyme into bone and sutures is not well understood, function of Lmx1b, a gene encoding a LIM-domain homeodomain transcription factor, plays a key role in this process. In the current study, we investigated a difference in the function of Lmx1b in different parts of the calvaria using neural crest-specific and mesoderm-specific Lmx1b mutants. We found that Lmx1b was obligatory for development of the interfrontal suture and the anterior fontanel along the dorsal midline of the skull, but not for the posterior fontanel over the midbrain. Also, Lmx1b mutation in the neural crest-derived mesenchyme, but not the mesoderm-derived mesenchyme, had a non-cell autonomous effect on coronal suture development. Furthermore, overexpression of Lmx1b in the neural crest lineage had different effects on the position of the coronal suture on the apical part and the basal part. Other unexpected phenotypes of Lmx1b mutants led to an additional finding that the coronal suture and the sagittal suture are of dual embryonic origin. Together, our data reveal a remarkable level of regional specificity in regulation of calvarial development.

BACKGROUND:Many cleft centers incorporate NasoAlveolar Molding (NAM) into their presurgical treatment protocols. However, there are limited data on eligible patients who do not receive or complete NAM. This study characterizes the demographics associated with non-utilization or completion of NAM. METHODS:A single-institution retrospective review was performed of all patients with cleft lip and alveolus undergoing primary unilateral and bilateral cleft lip repair from 2012-2020. Patients were grouped based on utilization or non-utilization of NAM. Demographic and treatment data were collected, including documented reasons for not pursuing or completing NAM. RESULTS: < .001). CONCLUSIONS:Common reasons for non-utilization of NAM include well-aligned cleft alveolus, medical complexity, and late presentation. Early presentation is an important modifiable factor affecting rates of NAM utilization.

The purpose of this study was to evaluate the influence of implant design features on osseointegration parameters. Two different implant macrogeometries and surface treatments were evaluated as follows: (1) progressive buttress threads possessing the SLActive surface (SLactive/BL), and (2) inner and outer trapezoidal threads possessing nano-hydroxyapatite coating over a dual acid-etched surface (Nano/U). Implants were placed in the right ilium of 12 sheep, and histologic/metric analyses were conducted after 12 weeks in vivo. The percentage of bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) within the threads were quantified. Histologic observations showed more intimate BIC in the SLactive/BL group compared to the Nano/U group. In contrast, the Nano/U group depicted woven bone formation generated between the wall of the osteotomy and implant threads within the healing chambers, while bone remodeling was evident at the tip of the outer thread. The SLActive/BL group presented higher BIC than the Nano/U group. On the other hand, significantly higher BAFO was observed at 12 weeks in the Nano/U group compared to the SLactive/BL group (P < .042). Differences in implant design features influenced the osseointegration pathway, which supports the need for further investigations to describe the clinical performance and differences in a timely fashion.

As a biologic product derived from human tissue, acellular dermal matrices (ADMs) did not require pre-market approval for their initial use as a soft tissue support product. Since their first utilization in breast surgery, ADMs have allowed for numerous advances in breast reconstruction. ADMs quickly gained popularity in breast surgery and are frequently utilized in various applications. During an investigation into potential factors leading to breast implant-associated anaplastic large cell lymphoma, the United States Food and Drug Administration (FDA) made an official statement that ADMs were not approved for use in breast reconstruction and that using ADMs in breast surgery was considered off-label. This special topic article details the history of ADMs in breast surgery and describes the ongoing evolution of the relationship between the FDA and ADMs.

BACKGROUND:As facial feminization surgery (FFS) continues to grow in access and popularity, the need for secondary FFS can be expected to increase. The purpose of this study was to identify reasons for FFS reoperation and offer recommendations to minimize secondary surgery. METHODS:A retrospective cohort study of patients who underwent FFS from October 2017 to 2021 was performed. Patients who underwent nonstaged secondary surgery were identified and sorted in 2 non-mutually exclusive surgical cohorts: additional surgery, defined as unplanned additional feminization surgery on previously unoperated facial units, and revision surgery, defined as redo surgery on previously operated facial units. Reasons for secondary surgery were examined in the context of the senior author's experience. RESULTS:Of 161 patients who underwent FFS, 41 (25.5%) underwent secondary surgery consisting of additional surgery (n = 32) and/or revision surgery (n = 30). There were no significant differences in clinical or demographic data between the secondary surgery and total FFS cohorts. Among additional surgery patients, facial units that had been previously operated on were as follows: nose (46.3%), trachea (31.7%), forehead/brow (22.0%), chin (12.2%), lips (9.8%), and cheeks (7.3%). Among revision patients, facial units revised were as follows: nose (36.6%), forehead/brow (26.8%), cheeks (17.1%), chin (17.1%), lips (12.5%), and trachea (2.4%). The main indication for revision for all facial units was undercorrection to feminine ideals. CONCLUSIONS:One-quarter of patients who underwent FFS had prior FFS and/or sought revision. Keeping in mind that the dominant indication for revision was undercorrection, FFS surgeons can minimize the need for secondary surgery in the future.

The aim of this study was to clinically evaluate the guided bone regeneration (GBR) potential of allograft, xenograft, and alloplastic materials in combination with resorbable membranes in extraction sockets. The qualitative and quantitative assessments of this prospective study were accomplished through histologic and histomorphometric analysis. Three experimental groups and 1 control group for comparison (n = 8) received either an allograft (human cancellous bone, freeze dried, Deutsches Institut für Zell und Gewebeersatz, Berlin, Germany), xenograft (BioOss, Geistlich Pharma AG, Wolhusen, Switzerland), or alloplast (biphasic calcium sulphate, Bondbone, MIS Implants Technologies Ltd., Charlotte, NC). The negative control group received no regenerative material. Tissue samples were then qualitatively and quantitatively evaluated as a function of percentage of new vital bone, graft particles content, soft tissue, and bone marrow over time. All 3 study groups presented bone volume suitable for the successful placement of a dental implant. The xenograft group yielded significantly less amount of vital bone compared with the allograft and alloplast groups. When comparing the percentage of residual graft particles, there was significantly greater amounts associated with the xenograft group in contrast to the allograft and alloplast groups. Similarly, a significantly increased amount of soft tissue percentage was observed within the xenograft group relative to all other groups. No significant differences were observed in the percentage of residual graft particles between the allograft and alloplast groups. There were also no significant differences detected in vital bone percentage between the allograft, alloplast, and control groups. When evaluating the bone marrow percentage, the only significant difference detected was between the xenograft and alloplast materials. Overall, no complications (ie, fever, malaise, purulence or fistula) were observed during the entirety of clinical trial among all patients. The greatest GBR potential was associated with the allograft material because of the greater degree of vital bone and the lowest percentage of residual graft particles. All studied bone substitute materials resulted in bone apposition for efficient use in alveolar ridge preservation procedures.

Leukocyte-platelet-rich fibrin (L-PRF) has been suggested for gap management for immediate implant placement when the distance is greater than 2 mm. However, there remains a paucity in hierarchically designed research to support this application. The present study aimed to evaluate the effect of L-PRF on the osseointegration parameters of dental implants placed after conventional osteotomy of surgically created bone defects that simulate post extraction sockets in a canine model after 3, 6, and 12 weeks in vivo. Eighty dental implants (Intra-Lock, Boca Raton, FL) were placed in the radius of 13 beagle dogs. The experiment consisted of 4 groups (n = 20 implants/group): 1) Regular osteotomy (Reg n/L-PRF); 2) Regular osteotomy and implant placement with L-PRF membrane (Reg L-PRF); 3) Wide osteotomy with no gap management performed, where an osteotomy/bony defect (6 mm of diameter and ~5 mm deep) was created to simulate immediate implant placement in post-extraction sockets, and the gap was left for spontaneous healing (Wide nL-PRF); and 4) Wide osteotomy with L-PRF gap management (Wide L-PRF). L-PRF membranes were obtained by blood drawn from each subject and centrifuged at 2700 rpm (408 RCF-clot) for 12 min. In the experimental groups where L-PRF was utilized, the membrane was inserted into the osteotomy site prior to implant placement. Six dogs had implants placed in the radius for 3 weeks; and 7 dogs had implants placed in the left radius for 6 weeks and in the right radius for 12 weeks. At the corresponding experimental time points, samples were harvested, and subjected to histological processing for qualitative and quantitative analyses, via bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO). Qualitative analysis demonstrated increased amounts of bone formation around the implant and within the healing chambers over time for all groups. While comparable histological features were observed for both Reg groups (L-PRF and nL-PRF), the gap management performed in Wide L-PRF group resulted in effective gap filling with improved bone growth in close proximity to the implant surface. Quantitative analyses of BIC and BAFO yielded higher values for both variables at 3 weeks for Wide L-PRF (~38% and ~56% respectively) compared to Wide nL-PRF (~20% for BIC and BAFO) (p < .03). No statistical differences were detected between Wide groups at 6 and 12 weeks, neither between Reg groups, independent of the association with or without the L-PRF membrane at all healing times. L-PRF placed within wide osteotomies, prior to implant placement, resulted in increased early bone formation compared to unfilled wide osteotomies at the early healing time (3 weeks in vivo).

The aim of this study was to evaluate the in vivo performance of two different deproteinized bovine bone (DBB) grafting materials: DBBB (Bio-Oss®) and DBBL (Laddec®), for the regeneration of critically sized (8 mm) defects in rabbit's calvaria. Three round-shaped defects were surgically created in the calvaria of 13 New Zealand White rabbits proximal to the coronal suture in the parietal bone. Two of the defects were filled with one of the grafting materials while a third was left empty to serve as a negative control. Bone regeneration properties were evaluated at 4- and 8-weeks after implantation by means of histological and histomorphometrical analyses. Statistical analyses were performed through a mixed model analysis with fixed factors of time and material. Histological evaluation of the control group evidenced a lack of bridging bone formation across the defect sites at both evaluation time points. For the experimental groups, new bone formation was observed around the defect periphery and to progress radially inwards to the center of the defect site, regardless of the grafting material. Histomorphometric analyses at 4 weeks demonstrated higher amount of bone formation through the defect for DBBB group. However, at 8 weeks, DBBL and DBBB demonstrated osteoconductivity and low resorption rates with evidence of statistically similar bone regeneration through the complete boney defect. Finally, DBBB presented lower soft tissue migration within the defect when compared to DBBL at both evaluation time points. DBBB and DBBL presented similar bone regeneration performance and slow resorption rates. Although both materials promoted bone regeneration through the complete defect, DBBB presented lower soft tissue migration within the defects at 4- and 8-weeks.

While the majority of the initial attention to symptomatic COVID-19 focused on adult patients as well as adult critical care and first responders, the pandemic drastically altered care throughout the entire health care industry. COVID-19 has had a profound effect on the treatment and care of pediatric patients within pediatric otolaryngology. The objective of this article is to highlight the unique ramifications of COVID-19 in general and its effect within pediatric otolaryngology, with a focus on the immediate and potential long-term shifts in practice. This article addresses several aspects of care within pediatric otolaryngology including safety, diagnosis, and treatment of COVID-19 detailing the unique effects of the pandemic on the pediatric otolaryngology specialty and opportunities.

Computerised surgical planning (CSP) and computer-aided design and manufacturing (CAD/CAM) have been demonstrated to increase surgical accuracy and reduce operative time in free flap mandibular reconstruction, but evidence is lacking as to their impact on patient-centred outcomes. Implant-supported dental prostheses, however, have been associated with improved quality of life outcomes following free flap mandibular reconstruction. We aim to review reported patient-centred outcomes in mandibular reconstruction with CSP and CAD/CAM and determine whether use of these technologies is associated with higher rates of dental implant placement following free flap mandibular reconstruction. On December 20, 2020, a systematic review and meta-analysis were conducted according to PRISMA guidelines for studies reporting quality of life, functional outcomes, and rates of dental implant placement in computer-aided free flap mandibular reconstruction. A random-effects meta-analysis was performed to compare dental implant placement rates between surgeries using CSP and those using conventional freehand techniques. A total of 767 articles were screened. Nine articles reporting patient-centred outcomes and 16 articles reporting dental implant outcomes were reviewed. Of those reporting dental implant outcomes, five articles, representing a total of 302 cases, were included in the meta-analysis. Use of CSP was associated with a significant increase in the likelihood of dental implant placement, with an odds ratio of 2.70 (95% CI 1.52 to 4.79, p = 0.0007). Standardised reporting methods and controlled studies are needed to further investigate the impact of CSP and CAD/CAM technologies on functional outcomes and patient-reported quality of life in free flap mandibular reconstruction. Use of CSP and CAD/CAM technologies is associated with higher rates of dental implant placement in patients undergoing free flap mandibular reconstruction when compared to conventional freehand techniques.