Facial Projection Research Articles

Three-Dimensional Composite Heatmaps of Unilateral Lambdoid Synostosis and Deformational Plagiocephaly

Background: The differentiation of unilateral lambdoid synostosis (ULS) and deformational plagiocephaly (DP) is vital to provide appropriate treatment intervention. Three-dimensional (3D) photo grammetry provides rapid, reproducible image capture without radiation exposure. Advanced analytical methods can help identify distinctive features to differentiate the two craniofacial conditions. This study uses 3D photogrammetry of ULS and DP patients to analyze the global cranial morphology for diagnostic differentiation. Methods: A retrospective review of 3D photogrammetry of 19 ULS and 25 DP patients were analyzed. Cranial vault asymmetry index, oblique cranial length ratio, and diagonal difference were measured. 3D photogrammetry-based composites were created and overlaid on age and gender-matched controls to generate heat maps representing morphologic differences in contour. Results: Cranial vault asymmetry index and oblique cranial length ratio were significantly different between ULS and DP (0.019; 0.022). 3D photogrammetry ULS composite showed retrusion in the ipsilateral occipitoparietal area, contralateral posterior parietal projection, contralateral frontal projection, relative ipsilateral mastoid bulge, and facial projection. DP composite showed unilateral occipital projection and contralateral anterior projection. The contralateral occipital regions in the occipital and anterior areas remained equivocal to control patients. Conclusions: Diagnostic differentiation of ULS and DP has previously relied on observation and linear measurements of cranial asymmetry in a single plane. 3D photogrammetry composites provide a global contour evaluation for diagnosis and longitudinal outcome analysis.

A New Virtual Reconstruction of the Ndutu Cranium

The Ndutu cranium is a partial, fragmented, and distorted hominin specimen from the Lake Ndutu site in Tanzania. It was first reconstructed by R. J. Clarke in 1976 and later revisited using now-outdated techniques. Consequently, features such as facial projection, cranial height/length, and cranial flexion are contestable. Here, we present a new virtual reconstruction following a transparent and replicable approach that employs virtual anthropology techniques to reassemble, mirror, digitally align, complete the cranium, and remove the effect of plastic deformation. Before deciding on an approach to align the unarticulated fragments, we tested the effects of symmetrization and the use of surface semilandmarks on the performance of our tool of choice: the digital alignment tool (DTA), developed by A. Profico and colleagues in 2019. Upon completion, we compare our reconstruction to a sample of Pleistocene hominin crania via geometric morphometrics. Test results reveal that DTA performance varies by fragment and that the use of surface semilandmarks bears no statistically significant advantage. We found our reconstruction to boast a more prognate and narrower face with a less flexed cranium overall than previous reconstruction efforts. The shape of the reconstructed cranial vault of Ndutu resulted closest to Sima de los Huesos (SH) 5, while its sagittal profile was most similar to Kabwe’s, lending support to J. L. Arsuaga and colleagues’ 1997 work and to P. Rightmire’s, respectively. We warn that further work is necessary before settling the debate surrounding Ndutu’s phylogeny. However, if our reconstruction hypothesis is held, its inclusion in future morphological studies is granted.

Incorporating the Osseous Genioplasty Into Rejuvenation of the Lower Face.

The chin plays a critical role in the shape, projection, and soft tissue support of the lower face. Osseous genioplasty is a powerful tool in facial rejuvenation as it allows for optimal control of the resulting chin dimensions and improvement in submental and submandibular laxity. Osseous genioplasty can be used alone or in combination with other facial rejuvenation procedures to achieve an optimal result. The aim of this study was to present the senior author's approach to skeletal analysis of the lower facial third and propose an algorithm that can be used to optimize skeletal support of the overlying soft tissue laxity while maintaining an aesthetic facial shape and proportion of the chin. All patients undergoing cosmetic osseous genioplasty for soft tissue rejuvenation of the lower face and/or perioral region with the senior author between 2010 and 2021 were retrospectively reviewed. Complications, including infection, numbness, and prolonged ecchymosis, were recorded. A total of 37 patients underwent cosmetic osseous genioplasty. The average age of the cohort was 44.5 years. Twenty-six patients (70.3%) were female. Eleven patients (29.7%) underwent genioplasty alone. In addition to genioplasty, 8 patients (21.6%) underwent orthognathic surgery, 5 patients (13.5%) underwent platysmaplasty and liposuction, and 2 patients (5.4%) underwent facelift. The authors propose an algorithm to guide evaluation of the lower facial third to help determine the possible role of osseous genioplasty for facial rejuvenation based on each patient's unique facial characteristics. In properly selected patients, osseous genioplasty can improve lower facial projection, submandibular laxity, and perioral soft tissue support while also optimizing facial shape and proportion.

Treacher collins syndrome- A case report

Treacher Collins syndrome (TCS), mandibulofacial dysostosis, or Franceschetti–Zwahlen–Klein syndrome, is a rare genetic disorder characterised by dysgenesis of the hard and soft tissues of first and second branchial arches. Bimaxillary surgery can improve the maxillomandibular facial projection. In this article we shows maxillofacial management of 23 year old male with Treacher Collins Syndrome. Keywords: Treacher, Collins, Syndrome..

Objective evaluation of orbito-zygomatic reconstruction with scapular tip free flaps to restore facial projection and orbital volume

BackgroundRestoring anatomical contour and position of the malar eminence and orbital rim following ablative mid-face procedures is critical in maintaining facial contour and orbit position. ObjectiveTo report our reconstructive approach using the scapular tip free-flap (STFF) for orbito-zygomatic defects, evaluating contour and overall shape restoration. MethodsThe study included 2 series: a clinical cohort of 15 consecutive patients who underwent an orbito-zygomatic reconstruction with a STFF and a cohort of 10 patients who had CT scan imaging but did not have orbito-zygomatic surgical resection or reconstruction. Using a 3D software, overall conformance (OC) and contour conformance (CC) with respect to the mirrored contralateral (clinical cohort) or native zygoma (preclinical cohort) were analyzed. Postoperative orbital volumes were also measured in the clinical cohort. Mean, median, root-mean-square (RMS), minimum and maximum measurements were obtained both for OC and CC. Conformance values of clinical and preclinical cohort were compared to objectively evaluate the quality of reconstruction in terms of orbito-zygomatic framework restoration (Mann-Whitney test). ResultsAll measurements for OC and CC between scapular tip and the zygoma showed no differences, both on the clinical (RMS: OC 3.29 mm vs CC 3.32 mm -p = NS-) and preclinical (RMS: OC 2.03 mm and CC 2.31 mm -p = NS-) cohorts. Moreover, there were no differences in post-operative orbital volumes in the clinical cohort. Clinical outcomes of the case-series are also reported. ConclusionThe STFF is highly effective in restoring facial projection and orbital volume in orbito-zygomatic reconstruction.

Osteotomized folded scapular tip free flap for complex midfacial reconstruction.

Aim:To describe a novel technique for the reconstruction of geometrically complex defects of the midface using an osteotomized folded scapular tip-free flap.Methods:Five patients underwent maxillectomy with defects disrupting two or more of the following facial axes: orbital, nasofacial, and palatal axes. Patients underwent primary reconstruction using an angular artery-based scapular tip-free flap with an osteotomy to fold the flap. Harvest techniques, including placement of osteotomies, folding and plating, surgical esthetic, and functional outcomes, are presented.Results:Osteotomies placed in the scapular tip-free flap allowed folding of the osseous flap and improved restoration of all three facial axes with a single flap. In one patient, the tip of the scapula was used to reconstruct the nasofacial axis, while the body and lateral border were used to reconstruct the palate. In four patients, the tip of the scapula was used to reconstruct the orbital axis, while the body and lateral border were used to reconstruct the nasofacial axis. Patients had successful oronasal separation, healed wounds withstanding adjuvant therapy, satisfactory orbital positioning and facial projection, preserved masticatory surfaces and opportunity for dental implants.Conclusion:The midface is geometrically complex and is one of the most challenging head and neck sites to reconstruct. Ablative defects in this area can disrupt facial axes resulting in poor esthetic and functional outcomes. This study demonstrates the reconstructive advantages of a novel osteotomized folded scapular tip-free flap.

Hyperbaric Oxygen Therapy in the Management of Zygomatic Bone Osteomyelitis.

Zygomatic bone osteomyelitis is a rare condition having an incidence of 1.42%. Zygomatic osteomyelitis can be due to haematogenous infection with tubercle bacillus, facial bone fractures or very rarely due to an unknown aetiology like in our case. If surgically managed alone, it would lead to complete loss of zygomatic bone, causing high morbidity to the patient in terms of function and aesthetics like loss of globe support causing dystopia, loss of facial projection causing facial asymmetry. Restoration of facial symmetry and globe support would require extensive procedures such as non-vascular bone grafting or patient-specific implant placement or microvascular bone flap transfer. Hyperbaric oxygen therapy (HBOT) was used to try and preserve the zygoma by promoting revascularisation. The patient received 100% oxygen at 2.5 absolute atmospheric pressure for 90 min, one session per day for 5 days in a week using a mask system in a multiplace chamber. The patient was reviewed clinically and radiologically after each 5 dives of HBOT sessions. After a total of 30 dives of HBOT, CT examination was repeated. There was partial reconstitution of cortical bone without any additional residual bone lesion. Minimal residual sequestra were noted. At this stage, the patient underwent conservative sequestrectomy in contrast to extensive surgery if HBOT was not contemplated. HBOT has the potential to be a very useful adjunct in the treatment of osteomyelitis in head and neck surgery; however, there is a need for carefully designed trials, avoiding methodological bias due to the great variability of patients, infectious agents, antibiotic resistance, host factors, to broaden the evidence of this therapeutic modality.

Variants in the Hippo Signaling Pathway are Associated with Craniofacial Skeletal Form and BMI

Childhood obesity rates in the United States have demonstrated a marked increase since the late 20th century. Current research has suggested that obesity can cause increases in bone density and an acceleration of skeletal growth. While studies have shown that obesity may be associated with altered craniofacial form, the mechanism and associated factors through which this interaction operates remains poorly understood. This study explores a potential link between obesity and craniofacial skeletal form as a function of the Hippo signaling pathway, an important regulator of organ size, tissue development, and craniofacial development.Lateral cephalograms from a sample of n=64 patients between the ages 7 to 17 were obtained from the Midwestern University Multispecialty Clinic. BMI percentile was computed for all children in the study following CDC guidelines (normal weight n=37, overweight n=9, obese n=18). 45 2D landmarks were registered via Generalized Procrustes Analysis (GPA) in order to facilitate a geometric morphometric (GM) analysis. Healthy Eating Index (HEI) scores obtained from Block Food Frequency Questionnaire (FFQ) surveys were used to control for the effects of diet in all subsequent analyses. Shape residuals were submitted to Principal Components Analysis (PCA) and Canonical Variate Analysis (CVA) to identify which aspects of skeletal form differentiate individual phenotypes based on BMI. Finally, associations between these phenotypes and 23 single nucleotide polymorphisms (SNPs) in seven genes within the Hippo signaling pathway were explored.Principal Components (PCs) accounting for at least 1% of facial shape variation were examined in order to determine components that differentiate between normal and obese groups. Based on this, suggestive/significant differences were found in PC 8 (p=0.056) and PC12 (p=0.012) based on BMI category. PC 8 (accounting for 3.6% of the total shape variation) indicates that chin projection, nose length, and mandibular morphology differentiate between normal and obese children. SNPs in TEAD3 (p=0.04) and FAT4 (p = 0.02) were significantly associated with shape variation along PC8. PC 12 (2.6% of the total shape variation) showed significant variation in chin projection and decreased incisor size in the obese group relative to the normal weight group. Additionally, a SNP within LATS2 (p = 0.04) was significantly correlated with shape variation along PC12. Finally, results from the CVA identified two components with CV2 indicating a significant relationship with LEF1 (p= 0.02). CV2 demonstrates increased facial projection in individuals with obesity.Across all analyses, we found a consistent pattern in mandibular length, facial projection, and incisor size that differentiated between normal and obese individuals. SNPs within key genes in the Hippo signaling pathway were associated with these phenotypes, indicating a potential causative relationship. Future studies will explore this relationship further.

Reconstruction of Complex Zygomatic Bone Defects Using Mirroring Coupled with EBM Fabrication of Titanium Implant

Reconstruction of zygomatic complex defects is a surgical challenge, owing to the accurate restoration of structural symmetry as well as facial projection. Generally, there are many available techniques for zygomatic reconstruction, but they hardly achieve aesthetic and functional properties. To our knowledge, there is no such study on zygomatic titanium bone reconstruction, which involves the complete steps from patient computed tomography scan to the fabrication of titanium zygomatic implant and evaluation of implant accuracy. The objective of this study is to propose an integrated system methodology for the reconstruction of complex zygomatic bony defects using titanium comprising several steps, right from the patient scan to implant fabrication while maintaining proper aesthetic and facial symmetry. The integrated system methodology involves computer-assisted implant design based on the patient computed tomography data, the implant fitting accuracy using three-dimensional comparison techniques, finite element analysis to investigate the biomechanical behavior under loading conditions, and finally titanium fabrication of the zygomatic implant using state-of-the-art electron beam melting technology. The resulting titanium implant has a superior aesthetic appearance and preferable biocompatibility. The customized mirrored implant accurately fit on the defective area and restored the tumor region with inconsequential inconsistency. Moreover, the outcome from the two-dimensional analysis provided a good accuracy within 2 mm as established through physical prototyping. Thus, the designed implant produced faultless fitting, favorable symmetry, and satisfying aesthetics. The simulation results also demonstrated the load resistant ability of the implant with max stress within 1.76 MPa. Certainly, the mirrored and electron beam melted titanium implant can be considered as the practical alternative for a bone substitute of complex zygomatic reconstruction.

Anthropometric Evaluation of Periorbital Region and Facial Projection Using Three-Dimensional Photogrammetry.

Direct anthropometric and three-dimensional (3D) photogrammetry measurements have been used extensively in cleft/craniofacial surgery to assess morphological changes and surgical outcomes. Craniofacial procedures alter the sagittal projection of periorbital bony prominences. Mulliken described a method of measuring their projection relative to the corneal plane but is impractical in clinical practice. Three-dimensional photogrammetry may offer a solution; however, the cornea is not visualized on this. The authors propose to develop new normative measurements of facial projection relative to the pupil. Five 3D photographs were taken of 5 individuals using Vectra M5 camera. Facial projection measurements were taken of the sagittal projection of the bilateral periorbital landmarks and nasal radix relative to the pupil using Mirror 3D analysis. Standard deviations (SD) were determined for each subject and laterality. Chi-square tests confirmed all SD <1 mm. Intra and inter-rater reliability were confirmed with an intraclass correlation coefficient assessment. Three male and 2 female subjects were photographed with 5 unique images. Standard deviations of repeat measures of all landmarks were <0.5 mm. Chi-square tests confirmed with statistical significance that SD for all values except for the radix was <1 mm (P<0.05). Intrarater reliability was high for all landmarks (intraclass correlation coefficient coefficients 0.93-0.99). Inter-rater reliability was good for the lateral canthi and excellent for all others. This technique demonstrates repeatability with high reliability on serial photographs and is applicable to measuring surgery effects and growth on facial projection. Establishment of age-specific normative values for landmark projection will refine usage applicability in operative planning.

The Unicorn exists! A remarkable new genus and species of Perilissini (Hymenoptera: Ichneumonidae) from South East Asia

Abstract Gilen gen. nov. (type species G. orientalis sp. nov.) from South East Asia is described and illustrated. The new taxon has a produced mid-longitudinal facial projection, which differentiates it from all other known genera of Ichneumonidae. It belongs to the tribe Perilissini in the subfamily Ctenopelmatinae (Hymenoptera, Ichneumonidae) and is recorded from Laos, Northern Thailand and Vietnam.

Computer-Assisted Reconstruction of the Hemimaxillectomy Defects With a Composite Iliac Crest Bone Free Flap: Case Reports

The authors present a revised application of the composite iliac crest bone free flap for hemimaxillectomy defects. This flap solely can give a support to the eye globe and the dental implants without osteotomies and titanium meshes. The upper ridge of the flap can be shaped to replicate the curvature of the orbital floor. The inner oblique muscle and the deep fascia can serve as an additional material for separation of the oral cavity from the nasal airway. Utilization of the Customized Contour Implants gives a surgeon a refining instrument for aesthetic correction of facial projection.

Functional Anatomic Computer Engineered Surgery Protocol for the Management of Self-Inflicted Gunshot Wounds to the Maxillofacial Skeleton

Virtual surgical planning (VSP) is an indispensable aid in craniomaxillofacial reconstruction, yet no protocol is established in facial gunshot wounds. We review our experience with computer-aided reconstruction of self-inflicted facial gunshot wounds (SIGSW'S) and propose a protocol for the staged repair. A retrospective case series enrolling patients with SIGSW's managed with the Functional Anatomic Computer Engineered Surgical protocol (FACES) was implemented. Subjects were evaluated at least one month postoperatively. Outcome variables were jaw position, facial projection, oro-nasal communication, lip competence, feeding tube and tracheostomy dependence, descriptive statistics were computed. The FACES protocol implemented during the initial hospitalization is as follows 1) damage control; 2) selective debridement; 3) VSP reconstruction back converted into navigation software 4) navigation assisted midfacial skeletal reconstruction; 5) computer aided oro-mandibular reconstruction with or without microvascular free flaps using custom cutting guides/hardware; 6) navigation assisted, computer aided palatomaxillary reconstruction with or without microvascular free flaps using cutting guides/hardware; 7) navigation assisted reconstruction of the internal orbit; 8) and confirmation of accurate reconstruction using intraoperative CT. The sample was composed of 10 patients, mean age of 43 years (range, 28 - 62 years, 70% M), 100% with SIGSW's to the submental/submandibular region. All had satisfactory facial projection (n=10), nine had satisfactory jaw position, were decannulated by one month's follow up and were feeding tube independent (90%). All traumatic oro-antral communications were closed (n=8, 7 surgical, 1 obturator), seven had adequate lip competence (70%). Complications included fibula malunion (n=1), plate exposure (n=2) infection (n=2), intracranial abscess (n=1) and microstomia (n=2). Computer-aided surgery is an indispensable tool in the reconstruction of SIGSW's. Successfully implemented, it proved to be a useful adjunct for: the restoration of orbital volume, facial projection and symmetry; the inset of composite tissue, and the facilitation of dental implant supported prosthetic rehabilitation.

Makeup Lamps: Live Augmentation of Human Faces via Projection

We propose the first system for live dynamic augmentation of human faces. Using projector-based illumination, we alter the appearance of human performers during novel performances. The key challenge of live augmentation is latency - an image is generated according to a specific pose, but is displayed on a different facial configuration by the time it is projected. Therefore, our system aims at reducing latency during every step of the process, from capture, through processing, to projection. Using infrared illumination, an optically and computationally aligned high-speed camera detects facial orientation as well as expression. The estimated expression blendshapes are mapped onto a lower dimensional space, and the facial motion and non-rigid deformation are estimated, smoothed and predicted through adaptive Kalman filtering. Finally, the desired appearance is generated interpolating precomputed offset textures according to time, global position, and expression. We have evaluated our system through an optimized CPU and GPU prototype, and demonstrated successful low latency augmentation for different performers and performances with varying facial play and motion speed. In contrast to existing methods, the presented system is the first method which fully supports dynamic facial projection mapping without the requirement of any physical tracking markers and incorporates facial expressions.

Evolution of a Surgical Philosophy in Orthognathic Surgery.

A surgical philosophy of orthognathic surgery is presented. It has evolved over an entire surgical career as orthognathic surgical goals have evolved to become primarily aesthetic. In this context, the occlusal result serves as a means of achieving the aesthetic ends. It relies on the physical examination, using qualitative concepts of facial appearance, to be the most important determinant of treatment plans. It makes a distinction between a quantitatively normal face and one that is visually well proportioned and emphasizes the attributes of the soft tissue. The emotional expression of the patient is also considered in treatment planning. By using surgical tactics that provide control of facial projection and height, this philosophy affords the surgeon an opportunity to manipulate the skeletal elements to the extent that one can simultaneously achieve a well-proportioned face and favorably influence the appearance of the soft tissues and facial countenance.

Recent trend and surgical management for panfacial fracture

Panfacial fracture is extremely difficult to manage facial injuries but concomitant injuries and severe complications including facial esthetic and functional problems can make it harder. Thorough evaluation and closed co-work with other specialists is needed when reduction and fixation cannot be achieved quickly. Emergency bony support and soft tissue key suture provide the patients with airway integrity, hard and soft tissue vitality. A systemic treatment plan must be made by 3D CT image. This plan include airway management for surgery, sequence of reduction and fixation, approach method, soft tissue resuspension and reconstruction of lost tissue like inferior orbital wall, zygomaic buttress and soft tissue. From known to unknown structures, accurate reduction and fixation will provide proper occlusion, facial projection, width, hight and function. Consideration about facial retaining ligaments must be given to prevent soft tissue sagging.

Cranial base topology and basic trends in the facial evolution of Homo

Facial prognathism and projection are important characteristics in human evolution but their three-dimensional (3D) architectonic relationships to basicranial morphology are not clear. We used geometric morphometrics and measured 51 3D-landmarks in a comparative sample of modern humans (N = 78) and fossil Pleistocene hominins (N = 10) to investigate the spatial features of covariation between basicranial and facial elements. The study reveals complex morphological integration patterns in craniofacial evolution of Middle and Late Pleistocene hominins. A downwards-orientated cranial base correlates with alveolar maxillary prognathism, relatively larger faces, and relatively larger distances between the anterior cranial base and the frontal bone (projection). This upper facial projection correlates with increased overall relative size of the maxillary alveolar process. Vertical facial height is associated with tall nasal cavities and is accommodated by an elevated anterior cranial base, possibly because of relations between the cribriform and the nasal cavity in relation to body size and energetics. Variation in upper- and mid-facial projection can further be produced by basicranial topology in which the midline base and nasal cavity are shifted anteriorly relative to retracted lateral parts of the base and the face. The zygomatics and the middle cranial fossae act together as bilateral vertical systems that are either projected or retracted relative to the midline facial elements, causing either midfacial flatness or midfacial projection correspondingly. We propose that facial flatness and facial projection reflect classical principles of craniofacial growth counterparts, while facial orientation relative to the basicranium as well as facial proportions reflect the complex interplay of head-body integration in the light of encephalization and body size decrease in Middle to Late Pleistocene hominin evolution. Developmental and evolutionary patterns of integration may only partially overlap morphologically, and traditional concepts taken from research on two-dimensional (2D) lateral X-rays and sections have led to oversimplified and overly mechanistic models of basicranial evolution.

Implications of the Relationship Between Basicranial Flexion and Facial Orientation for the Evolution of Hominid Craniofacial Structures

The basicranium and face have been linked through genetic, developmental, and functional relationships throughout their evolution. As a result, basicranial morphology most likely plays a major role in the evolution of facial structures. We describe the relationships between basicranial flexion and the face in Homo, Pan, and Gorilla to determine the role of cranial base angle reduction in the setup of the short and orthognathic face of Homo. We test the hypotheses that cranial base flexion plays a significant part in variation in facial orientation, length, and projection at the intraspecific level. The sample comprised 125 crania of adult specimens including 66 Homo sapiens, 32 Pan troglodytes, and 27 Gorilla gorilla. We described the cranial base and face using landmarks placed on scans of the surfaces and computed correlations between the cranial base angle and facial orientation, length, and projection. Our results support the hypotheses that cranial base flexion plays a significant part in facial orientation for Homo and Pan and in facial length for Pan. The hypothesis that basicranial flexion is related to a reduction of facial projection is not supported. The findings suggest that basicranial flexion can explain several anatomical specificities of hominins, including the reduction of prognathism and the reduction of the length of the nasopharynx. We found different patterns in the different genera, highlighting the fact that changes in the relationship between craniofacial structures may have occurred during hominid evolution.

Cephalometry in adults and children with neurofibromatosis type 1: Implications for the pathogenesis of sphenoid wing dysplasia and the “NF1 facies”

BackgroundNeurofibromatosis type 1 (NF1) is a common, autosomal dominant tumor-predisposition disorder that arises secondary to mutations in the tumor suppressor gene NF1. Cephalometry is an inexpensive, readily available and non-invasive technique that is under-utilized in studying the NF1 craniofacial phenotype. An analysis of NF1 cephalometry was first published by Heervä et al. in 2011. We expand here on that first investigation with a larger cohort of adult and pediatric patients affected with NF1 and sought objective insight into the NF1 facies, said to feature hypertelorism and a broad nasal base, from cephalometric analysis. MethodsWe obtained cephalograms from 101 patients with NF1 (78 adults and 23 children) from two NF1 protocols at the National Institutes of Health. Each subject had an age-, gender- and ethnicity-matched control. We used Dolphin software to make the cephalometric measurements. We assessed the normality of differences between paired samples using the Shapiro–Wilk test and evaluated the significance of mean differences using paired t-tests and adjusted for multiple testing. We explored the relationship between the cephalometric measurements and height, head circumference and interpupillary distance. ResultsIn this dataset of American whites with NF1, we confirmed in a modestly larger sample many of the findings found by Heerva et al. in an NF1 Finnish cohort. We found a shorter maxilla, mandible, cranial base, (especially anteriorly, p = 0.0001) and diminished facial height in adults, but not children, with NF1. Only one adult exhibited hypertelorism. ConclusionsThe cephalometric differences in adults arise in part from cranial base shortening and thus result in a shorter face, mid-face hypoplasia, reduced facial projection, smaller jaw, and increased braincase globularity. In addition, we suggest that NF1 sphenoid bone shortening, a common event, is consistent with an intrinsic NF1 bone cell defect, which renders the bone more vulnerable to a random “second hit” in NF1, leading to sphenoid wing dysplasia, a rare event.

Optimizing Hybrid Occlusion in Face-Jaw-Teeth Transplantation: A Preliminary Assessment of Real-Time Cephalometry as Part of the Computer-Assisted Planning and Execution Workstation for Craniomaxillofacial Surgery.

The aesthetic and functional outcomes surrounding Le Fort-based, face-jaw-teeth transplantation have been suboptimal, often leading to posttransplant class II/III skeletal profiles, palatal defects, and "hybrid malocclusion." Therefore, a novel technology-real-time cephalometry-was developed to provide the surgical team instantaneous, intraoperative knowledge of three-dimensional dentoskeletal parameters. Mock face-jaw-teeth transplantation operations were performed on plastic and cadaveric human donor/recipient pairs (n = 2). Preoperatively, cephalometric landmarks were identified on donor/recipient skeletons using segmented computed tomographic scans. The computer-assisted planning and execution workstation tracked the position of the donor face-jaw-teeth segment in real time during the placement/inset onto recipient, reporting pertinent hybrid cephalometric parameters from any movement of donor tissue. The intraoperative data measured through real-time cephalometry were compared to posttransplant measurements for accuracy assessment. In addition, posttransplant cephalometric relationships were compared to planned outcomes to determine face-jaw-teeth transplantation success. Compared with postoperative data, the real-time cephalometry-calculated intraoperative measurement errors were 1.37 ± 1.11 mm and 0.45 ± 0.28 degrees for the plastic skull and 2.99 ± 2.24 mm and 2.63 ± 1.33 degrees for the human cadaver experiments. These results were comparable to the posttransplant relations to planned outcome (human cadaver experiment, 1.39 ± 1.81 mm and 2.18 ± 1.88 degrees; plastic skull experiment, 1.06 ± 0.63 mm and 0.53 ± 0.39 degrees). Based on this preliminary testing, real-time cephalometry may be a valuable adjunct for adjusting and measuring "hybrid occlusion" in face-jaw-teeth transplantation and other orthognathic surgical procedures.