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1.
J Robot Surg ; 18(1): 254, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38878229

RESUMEN

The role of robotics has grown exponentially. There is an active interest amongst practitioners in the transferability of the potential benefits into plastic and reconstructive surgery; however, many plastic surgeons report lack of widespread implementation, training, or clinical exposure. We report the current evidence base, and surgical opportunities, alongside key barriers, and limitations to overcome, to develop the use of robotics within the field. This systematic review of PubMed, Medline, and Embase has been conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PROSPERO (ID: CRD42024524237). Preclinical, educational, and clinical articles were included, within the scope of plastic and reconstructive surgery. 2, 181, articles were screened; 176 articles met the inclusion criteria across lymph node dissection, flap and microsurgery, vaginoplasty, craniofacial reconstruction, abdominal wall reconstruction and transoral robotic surgery (TOR). A number of benefits have been reported including technical advantages such as better visualisation, improved precision and accuracy, and tremor reduction. Patient benefits include lower rate of complications and quicker recovery; however, there is a longer operative duration in some categories. Cost presents a significant barrier to implementation. Robotic surgery presents an exciting opportunity to improve patient outcomes and surgical ease of use, with feasibility for many subspecialities demonstrated in this review. However, further higher quality comparative research with careful case selection, which is adequately powered, as well as the inclusion of cost-analysis, is necessary to fully understand the true benefit for patient care, and justification for resource utilisation.


Asunto(s)
Procedimientos de Cirugía Plástica , Procedimientos Quirúrgicos Robotizados , Femenino , Humanos , Pared Abdominal/cirugía , Escisión del Ganglio Linfático/métodos , Microcirugia/métodos , Tempo Operativo , Procedimientos de Cirugía Plástica/métodos , Procedimientos Quirúrgicos Robotizados/métodos
2.
Plast Reconstr Surg Glob Open ; 12(1): e5382, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38204867

RESUMEN

Background: The pursuit of understanding facial beauty has been the subject of scientific interest since time immemorial. How beauty is associated with other perceived attributes that affect human interaction remains elusive. This article aims to explore how facial attractiveness correlates with health, happiness, femininity, and perceived age. We review the existing literature and report an empirical study using expert raters. Methods: A peer-reviewed database of 2870 aesthetic female faces with a global ethnic distribution was created. Twenty-one raters were asked to score frontal images on the attributes of health, happiness, femininity, perceived age, and attractiveness, on a Likert scale of 0-100. Results: Pearson correlation coefficients ("r") were calculated to correlate attributes, with multiple regression analyses and P values calculated. Strong positive correlation was found between attractiveness and health (r = 0.61, P < 0.05), attractiveness and femininity (r = 0.7, P < 0.05), and health and femininity (r = 0.57, P < 0.05); medium positive correlation between health and happiness (r = 0.31, P < 0.05); and small positive correlation between happiness and femininity (r = 0.21, P < 0.05). A neutral relationship was observed between perceived age and happiness (0.01, P = 0.75), and medium negative correlation between perceived age and attractiveness (-0.32, P < 0.05), health (-0.36, P < 0.05), and femininity (-0.31, P < 0.05). Conclusions: Our study illustrates a positive correlation between the positive attributes of health, happiness, femininity and attractiveness, with a negative correlation of all characteristics with increasing perceived age. This provides insight into the complexity of human interaction and provides a holistic view of attraction as being a gateway to the reflexive perception of other attributes. The implications encourage an aesthetic focus on facial reconstruction.

3.
Aesthet Surg J Open Forum ; 5: ojad082, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37780530

RESUMEN

Background: Facial reconstruction surgery is often a complex and staged process, leading to lengthy reconstructive journeys for patients. The integration of a clinical pathway can give patients a clearer understanding of what to expect at each stage of their reconstructive journey. Objectives: The authors demonstrate how the incorporation of multidisciplinary team clinics, three-dimensional (3D) photography, and 3D modeling into an integrated pathway can streamline the process for patients undergoing facial reconstructive surgeries and aid their understanding of their surgeries. Methods: A novel clinical pathway was developed for patients undergoing facial reconstructive surgery at a tertiary reconstructive unit in London. A case series was collated of 35 patients who had been through the integrated pathway. Patient-reported outcome measures (PROMs) were assessed using FACE-Q scales, Global Aesthetic Improvement Scale, Self-Perception of Age score, and Ordinal Rank change in facial aesthetic appearance, determined subjectively and objectively. Statistical analysis was performed to calculate mean averages for each scale and PROM. Results: High patient satisfaction with overall facial appearance, aging appearance, and the decision-making process was demonstrated. The average perceived improvement in age-related facial appearance was -7.7 years postreconstruction compared with prereconstruction. The Ordinal Rank improvement on facial aesthetic appearance showed considerable improvement, both subjectively and objectively. Conclusions: The authors advocate the implementation of an integrated clinical pathway for facial reconstruction, with positive impacts observed in terms of patient satisfaction and objective assessments of facial appearance. Similar principles can be extrapolated to other aspects of reconstructive surgery.

4.
Aesthet Surg J ; 44(1): NP1-NP15, 2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-37695808

RESUMEN

BACKGROUND: To achieve the goal of enhancing facial beauty it is crucial for aesthetic physicians and plastic surgeons to have a deep understanding of aesthetic ideals. Although numerous aesthetic criteria have been proposed over the years, there is a lack of empirical analysis supporting many of these standards. OBJECTIVES: This aim of this review was to undertake the first exploration of the empirical evidence concerning the aesthetic ideals of the face in the existing literature. METHODS: A comprehensive search in MEDLINE, Embase, Scopus and CENTRAL databases was conducted for primary clinical studies reporting on the classification of the facial aesthetic units as per the Gonzales-Ulloa facial aesthetic unit classification from January 1962 to November 2022. RESULTS: A total of 36 articles were included in the final review: 12 case series, 14 cohort studies, and 10 comparative studies. These described the aesthetic ideals of the following areas: forehead (6 studies; mean level of evidence, 3.33); nose (9 studies; mean level of evidence, 3.6); orbit (6 studies; mean level of evidence, 3); cheek (4 studies; mean level of evidence, 4.07); lips (6 studies; mean level of evidence, 3.33); chin (4 studies; mean level of evidence, 3.75); ear (1 study; level of evidence, 4). CONCLUSIONS: The units that were most extensively studied were the nose, forehead, and lip, and these studies also appeared in journals with higher impact factors than other subunits. Conversely, the chin and ear subunits had the fewest studies conducted on them and had lower impact factors. To provide a useful resource for readers, it would be prudent to identify and discuss influential papers for each subunit.


Asunto(s)
Frente , Nariz , Humanos , Estética , Mejilla , Labio/cirugía
5.
Aesthet Surg J Open Forum ; 5: ojad072, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37638342

RESUMEN

Background: Understanding the differences in facial shapes in individuals from different races is relevant across several fields, from cosmetic and reconstructive medicine to anthropometric studies. Objectives: To determine whether there are features shared by the faces of an aesthetic female face database and if they correlate to their racial demographics using novel computer modeling. Methods: The database was formed using the "top 100 most beautiful women" lists released by "For Him Magazine" for the last 15 years. Principal component analysis (PCA) of 158 parameters was carried out to check for clustering or racial correlation with these clusters. PCA is a machine-learning tool used to reduce the number of variables in a large data set, allowing for easier analysis of the data while retaining as much information as possible from the original data set. A review of the literature on craniofacial anthropometric differences across ethnicities was also undertaken to complement the computer data. Results: Two thousand eight hundred and seventy aesthetic faces formed the database in the same racial proportion as 10,000 faces from the general population as a baseline. PCA clustering illustrated grouping by latent space parameters for facial dimensions but showed no correlation with racial demographics. There was a commonality of facial features within the aesthetic cohort, which differed from the general population. Fourteen papers were included in the review which contained 8142 individuals. Conclusions: Aesthetic female faces have commonalities in facial features regardless of racial demographic, and the dimensions of these features vary from the baseline population. There may even be a common human aesthetic proportion that transcends racial boundaries, but this is yet to be elucidated.

6.
Aesthet Surg J Open Forum ; 5: ojad062, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37575889

RESUMEN

Background: Reconstructive surgery operations are often complex, staged, and have a steep learning curve. As a vocational training requiring thorough three-dimensional (3D) understanding of reconstructive techniques, the use of 3D photography and computer modeling can accelerate this learning for surgical trainees. Objectives: The authors illustrate the benefits of introducing a streamlined reconstructive pathway that integrates 3D photography and computer modeling, to create a learning database for use by trainees and patients alike, to improve learning and comprehension. Methods: A computer database of 3D photographs and associated computer models was developed for 35 patients undergoing reconstructive facial surgery at the Royal Free Hospital, London, UK. This was used as a training and teaching tool for 20 surgical trainees, with an MCQ questionnaire assessing knowledge and a Likert scale questionnaire assessing satisfaction with the understanding of core reconstructive techniques, given before and after teaching sessions. Data were analyzed using the Mann-Whitney U test for trainee knowledge and Wilcoxon rank sum test for trainee satisfaction. Results: Trainee (n = 20) knowledge showed a statistically significant improvement, P < .01, as did trainee satisfaction, P < .05, after a teaching session using 3D photography and computer models for facial reconstruction. Conclusions: Three-dimensional photography and computer modeling are useful teaching and training tools for reconstructive facial surgery. The authors advocate the implementation of an integrated pathway for patients with facial defects to include 3D photography and computer modeling wherever possible, to develop internal databases for training trainees as well as patients. This algorithm can be extrapolated to other aspects of reconstructive surgery.

8.
J Oral Biol Craniofac Res ; 12(5): 512-515, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35774231

RESUMEN

Advances in high resolution 3D photography and computer modelling are revolutionising patient workup, surgical planning, patient satisfaction, clinical outcomes, and surgical training. We present a case in which this technology is utilised for a patient undergoing a forehead flap for reconstruction of a nasal defect, allowing us to develop a novel reconstructive algorithm. 3D photographs were taken pre-operatively, a computer model rendered and follow up photographs taken at each stage of the reconstruction using a Vectra XT camera. Patient satisfaction was measured qualitatively postoperatively. Prior to each stage we were able to use the 3D photographs to make thorough preoperative plans whilst minimising the number of outpatient appointments the patient required. With the images always at hand, we had much more time to make measurements and consider alterations. Utilising the 3D models in clinic and MDT allowed us to have more insightful outpatient appointments, in which we were able to discuss and illustrate each subsequent stage. The use of 3D photography and computer modelling allows for a greater level of care to patients by improving understanding and satisfaction and alleviating anxiety. It also reduced operative time, improves surgical planning, and acts as an excellent resource for surgical trainees and future patients.

9.
BMJ Case Rep ; 15(4)2022 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-35418372

RESUMEN

We describe the case of a patient with the rare complication of a chronic postaural fistula following repeated and extensive surgery and adjuvant radiotherapy to the head and neck for a pleomorphic adenoma of the parotid gland. This case demonstrates the importance and value of thorough preoperative planning for major head and neck reconstruction, particularly if the area for reconstruction has distorted anatomy due to prior treatment or damage. In complex free flap reconstruction, it is important to investigate the recipient site with the help of arteriography and give due consideration to the donor site and its postoperative management. We highlight the importance of multidisciplinary work for the care of these patients not only intraoperatively, but also in the preoperative planning stage, and perhaps most importantly in the postoperative care.


Asunto(s)
Fístula , Colgajos Tisulares Libres , Neoplasias de Cabeza y Cuello , Mastoiditis , Procedimientos de Cirugía Plástica , Fístula/etiología , Fístula/cirugía , Antebrazo/cirugía , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Mastoiditis/cirugía , Estudios Retrospectivos
10.
Sci Rep ; 12(1): 2230, 2022 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-35140239

RESUMEN

Clinical diagnosis of craniofacial anomalies requires expert knowledge. Recent studies have shown that artificial intelligence (AI) based facial analysis can match the diagnostic capabilities of expert clinicians in syndrome identification. In general, these systems use 2D images and analyse texture and colour. They are powerful tools for photographic analysis but are not suitable for use with medical imaging modalities such as ultrasound, MRI or CT, and are unable to take shape information into consideration when making a diagnostic prediction. 3D morphable models (3DMMs), and their recently proposed successors, mesh autoencoders, analyse surface topography rather than texture enabling analysis from photography and all common medical imaging modalities and present an alternative to image-based analysis. We present a craniofacial analysis framework for syndrome identification using Convolutional Mesh Autoencoders (CMAs). The models were trained using 3D photographs of the general population (LSFM and LYHM), computed tomography data (CT) scans from healthy infants and patients with 3 genetically distinct craniofacial syndromes (Muenke, Crouzon, Apert). Machine diagnosis outperformed expert clinical diagnosis with an accuracy of 99.98%, sensitivity of 99.95% and specificity of 100%. The diagnostic precision of this technique supports its potential inclusion in clinical decision support systems. Its reliance on 3D topography characterisation make it suitable for AI assisted diagnosis in medical imaging as well as photographic analysis in the clinical setting.


Asunto(s)
Inteligencia Artificial , Craneosinostosis/clasificación , Craneosinostosis/diagnóstico , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Simulación por Computador , Craneosinostosis/diagnóstico por imagen , Cara/anomalías , Cabeza/anomalías , Humanos , Lactante , Tomografía Computarizada por Rayos X
12.
JPRAS Open ; 21: 28-34, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32158883

RESUMEN

Arhinia (congenital absence of the nose) is a congenital rare disease, which has been reported in less than 60 cases in the literature. It consists of the absence of external nose, nasal cavities and olfactory apparatus and is generally associated with midline defects, microphthalmia, blepharophimosis and hypotelorism. Aesthetic problems as well as associated functional anomalies can potentially impact on the development and interpersonal relationships of the child at a later stage in life. Arhinia requires extensive management in early life in order to ensure airway patency and protection by means of tracheostomy, and to allow adequate pharyngeal and feeding function to the child. Aesthetic issues are managed with reconstructive surgery or an external prosthesis. There is no previous description in Literature of internal prosthetic devices used to sequentially shape soft tissues in complex reconstruction. We present an example of design and manufacturing of a bespoke nose implant produced by means of 3D printing and directly assessed on-table by means of 3D surface scanning.

13.
Int J Comput Vis ; 126(2): 233-254, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31983806

RESUMEN

We present large scale facial model (LSFM)-a 3D Morphable Model (3DMM) automatically constructed from 9663 distinct facial identities. To the best of our knowledge LSFM is the largest-scale Morphable Model ever constructed, containing statistical information from a huge variety of the human population. To build such a large model we introduce a novel fully automated and robust Morphable Model construction pipeline, informed by an evaluation of state-of-the-art dense correspondence techniques. The dataset that LSFM is trained on includes rich demographic information about each subject, allowing for the construction of not only a global 3DMM model but also models tailored for specific age, gender or ethnicity groups. We utilize the proposed model to perform age classification from 3D shape alone and to reconstruct noisy out-of-sample data in the low-dimensional model space. Furthermore, we perform a systematic analysis of the constructed 3DMM models that showcases their quality and descriptive power. The presented extensive qualitative and quantitative evaluations reveal that the proposed 3DMM achieves state-of-the-art results, outperforming existing models by a large margin. Finally, for the benefit of the research community, we make publicly available the source code of the proposed automatic 3DMM construction pipeline, as well as the constructed global 3DMM and a variety of bespoke models tailored by age, gender and ethnicity.

14.
J Craniofac Surg ; 29(1): 45-48, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29040141

RESUMEN

Treatment of unicoronal craniosynostosis is a surgically challenging problem, due to the involvement of coronal suture and cranial base, with complex asymmetries of the calvarium and orbit. Several techniques for correction have been described, including surgical bony remodeling, early strip craniotomy with orthotic helmet remodeling and distraction. Current distraction devices provide unidirectional forces and have had very limited success. Nitinol is a shape memory alloy that can be programmed to the shape of a patient-specific anatomy by means of thermal treatment.In this work, a methodology to produce a nitinol patient-specific distractor is presented: computer tomography images of a 16-month-old patient with unicoronal craniosynostosis were processed to create a 3-dimensional model of his skull and define the ideal shape postsurgery. A mesh was produced from a nitinol sheet, formed to the ideal skull shape and heat treated to be malleable at room temperature. The mesh was afterward deformed to be attached to a rapid prototyped plastic skull, replica of the patient initial anatomy. The mesh/skull construct was placed in hot water to activate the mesh shape memory property: the deformed plastic skull was computed tomography scanned for comparison of its shape with the initial anatomy and with the desired shape, showing that the nitinol mesh had been able to distract the plastic skull to a shape close to the desired one.The shape-memory properties of nitinol allow for the design and production of patient-specific devices able to deliver complex, preprogrammable shape changes.


Asunto(s)
Aleaciones , Craneosinostosis/cirugía , Diseño de Equipo/métodos , Osteogénesis por Distracción/instrumentación , Mallas Quirúrgicas , Suturas Craneales/cirugía , Humanos , Lactante , Masculino , Modelos Anatómicos , Órbita/diagnóstico por imagen , Impresión Tridimensional , Prueba de Estudio Conceptual , Base del Cráneo/diagnóstico por imagen , Tomografía Computarizada por Rayos X
15.
J Neurosurg Pediatr ; 20(5): 400-409, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28841110

RESUMEN

OBJECTIVE Scaphocephaly secondary to sagittal craniosynostosis has been treated in recent years with spring-assisted cranioplasty, an innovative approach that leverages the use of metallic spring distractors to reshape the patient skull. In this study, a population of patients who had undergone spring cranioplasty for the correction of scaphocephaly at the Great Ormond Street Hospital for Children was retrospectively analyzed to systematically assess spring biomechanical performance and kinematics in relation to spring model, patient age, and outcomes over time. METHODS Data from 60 patients (49 males, mean age at surgery 5.2 ± 0.9 months) who had received 2 springs for the treatment of isolated sagittal craniosynostosis were analyzed. The opening distance of the springs at the time of insertion and removal was retrieved from the surgical notes and, during the implantation period, from planar radiographs obtained at 1 day postoperatively and at the 3-week follow-up. The force exerted by the spring to the patient skull at each time point was derived after mechanical testing of each spring model-3 devices with the same geometry but different wire thicknesses. Changes in the cephalic index between preoperatively and the 3-week follow-up were recorded. RESULTS Stiffer springs were implanted in older patients (p < 0.05) to achieve the same opening on-table as in younger patients, but this entailed significantly different-higher-forces exerted on the skull when combinations of stiffer springs were used (p < 0.001). After initial force differences between spring models, however, the devices all plateaued. Indeed, regardless of patient age or spring model, after 10 days from insertion, all the devices were open. CONCLUSIONS Results in this study provide biomechanical insights into spring-assisted cranioplasty and could help to improve spring design and follow-up strategy in the future.


Asunto(s)
Craneosinostosis/cirugía , Craneotomía/instrumentación , Procedimientos de Cirugía Plástica/métodos , Cráneo/cirugía , Cuidados Posteriores , Factores de Edad , Fenómenos Biomecánicos , Craneosinostosis/diagnóstico por imagen , Craneosinostosis/fisiopatología , Elasticidad , Femenino , Humanos , Lactante , Masculino , Estudios Retrospectivos , Cráneo/diagnóstico por imagen , Cráneo/fisiopatología
16.
Plast Reconstr Surg ; 140(1): 125-134, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28338584

RESUMEN

BACKGROUND: Spring-assisted cranioplasty has been proposed as an alternative to total calvarial remodeling for sagittal craniosynostosis. Advantages include its minimally invasive nature, and reduced morbidity and hospital stay. Potential drawbacks include the need for a second procedure for removal and the lack of published long-term follow-up. The authors present a single-institution experience of 100 consecutive cases using a novel spring design. METHODS: All patients treated at the authors' institution between April of 2010 and September of 2014 were evaluated retrospectively. Patients with isolated nonsyndromic sagittal craniosynostosis were included. Data were collected for operative time, anesthetic time, hospital stay, transfusion requirement, and complications in addition to cephalic index preoperatively and at 1 day, 3 weeks, and 6 months postoperatively. RESULTS: One hundred patients were included. Mean cephalic index was 68 preoperatively, 71 at day 1, and 72 at 3 weeks and 6 months postoperatively. Nine patients required transfusion. Two patients developed a cerebrospinal fluid leak requiring intervention. One patient required early removal of springs because of infection. One patient had a wound dehiscence over the spring and one patient sustained a venous infarct with hemiplegia. Five patients required further calvarial remodeling surgery. CONCLUSIONS: The authors' modified spring design and protocol represents an effective strategy in the management of single-suture sagittal craniosynostosis with reduced total operative time and blood loss compared with alternative treatment strategies. In patients referred within the first 6 months of birth, this technique has become the authors' procedure of choice. In a minority of cases, especially in the older age groups, further remodeling surgery is required. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


Asunto(s)
Craneosinostosis/cirugía , Procedimientos de Cirugía Plástica/instrumentación , Procedimientos de Cirugía Plástica/métodos , Cráneo/cirugía , Diseño de Equipo , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos
17.
Plast Reconstr Surg ; 139(2): 477e-487e, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28121883

RESUMEN

BACKGROUND: Crouzon-Pfeiffer syndrome is caused by mutations predominantly in the FGFR2 gene leading to syndromic craniosynostosis and midfacial hypoplasia. Monobloc distraction aims to correct both functional and aesthetic disharmony as a result of midfacial hypoplasia. This study evaluates the corrective effects and effectiveness of monobloc distraction in Crouzon-Pfeiffer patients. METHODS: Preoperative and postoperative scans were collected from 20 Crouzon and two Pfeiffer patients aged 7 to 20 years. Fifty-six normal skulls were used as a control group. Geometric morphometrics using 52 frontofacial landmarks were used to analyze the normal skull and preoperative and postoperative patient skulls. Color maps were created to visualize differences among the average normal, preoperative, and postoperative Crouzon-Pfeiffer patients. RESULTS: In the studied patient population, monobloc distraction with the use of an external distractor advanced the upper half of the midface more than the lower half of the midface. There was an anteroinferior rotation in the monobloc segment. The zygomatic arch length improved on average to 88 and 90 percent of normal (right and left, respectively), whereas globe protrusion was corrected from 134 percent to 84 percent and from 131 percent to 87 percent of normal (right and left, respectively) in the studied patient population. Compared with a normal skull, the maxillary region remained retruded. CONCLUSIONS: The advancement achieved by monobloc distraction is effective in the upper half of the midface; the lower half of the midface is advanced but remains retruded in comparison with the normal population. The midface is rotated anteroinferiorly. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


Asunto(s)
Acrocefalosindactilia/cirugía , Osteogénesis por Distracción/métodos , Acrocefalosindactilia/diagnóstico por imagen , Adolescente , Niño , Femenino , Humanos , Masculino , Resultado del Tratamiento , Adulto Joven
18.
J Craniofac Surg ; 27(1): 188-90, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26674894

RESUMEN

Forehead skin is widely acknowledged as a good donor site for total nasal reconstruction, thanks to its matching color, texture, and abundant vascularity. The forehead flap technique uses an axial pattern flap forehead skin to replace missing nasal tissue. To increase the amount of available tissue and reduce the size of the tissue defect after flap mobilization, tissue expanders may be used. Although this is a relatively established technique, limitations include reduced moldability of the forehead skin (which is thicker than the nasal skin), and the need for multiple sessions of expansion to achieve a sufficient yield to close the forehead.Shape-memory metals, such as nitinol, can be programmed to "remember" complex shapes. In this work, the methodology for producing a prototype of nitinol tissue expander able to mold the skin in a predetermined patient-specific skin shape is described. A realistic nose mold was manufactured using metal rapid prototyping; nitinol sheet and mesh were molded into nose-shape constructs, having hyperelastic as well as shape-memory capability. Computed tomography scanning was performed to assess the ability of the structure to regain its shape after phase transformation upon cooling within 2% of initial dimensions. The prototypes were implanted in a pig forehead to test its ability to impose a nose shape to the forehead skin.The shape-memory properties of nitinol offer the possibility of producing bespoke tissue expanders able to deliver complex, precisely designed skin envelopes. The hyperelastic properties of nitinol allow constant preprogrammed expansion forces to be generated throughout the expansion process.


Asunto(s)
Diseño Asistido por Computadora , Diseño de Prótesis , Rinoplastia/instrumentación , Trasplante de Piel/instrumentación , Colgajos Quirúrgicos/trasplante , Mallas Quirúrgicas , Dispositivos de Expansión Tisular , Adulto , Aleaciones/química , Animales , Módulo de Elasticidad , Femenino , Frente/cirugía , Humanos , Imagenología Tridimensional/métodos , Ensayo de Materiales , Modelación Específica para el Paciente , Rinoplastia/métodos , Propiedades de Superficie , Porcinos , Tomografía Computarizada por Rayos X/métodos
19.
J Craniomaxillofac Surg ; 43(4): 528-36, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25792443

RESUMEN

UNLABELLED: Crouzon and Pfeiffer syndrome are syndromic craniosynostosis caused by specific mutations in the FGFR genes. Patients share the characteristics of a tall, flattened forehead, exorbitism, hypertelorism, maxillary hypoplasia and mandibular prognathism. Geometric morphometrics allows the identification of the global shape changes within and between the normal and syndromic population. METHODS: Data from 27 Crouzon-Pfeiffer and 33 normal subjects were landmarked in order to compare both populations. With principal component analysis the variation within both groups was visualized and the vector of change was calculated. This model normalized a Crouzon-Pfeiffer skull and was compared to age-matched normative control data. RESULTS: PCA defined a vector that described the shape changes between both populations. Movies showed how the normal skull transformed into a Crouzon-Pfeiffer phenotype and vice versa. Comparing these results to established age-matched normal control data confirmed that our model could normalize a Crouzon-Pfeiffer skull. CONCLUSIONS: PCA was able to describe deformities associated with Crouzon-Pfeiffer syndrome and is a promising method to analyse variability in syndromic craniosynostosis. The virtual normalization of a Crouzon-Pfeiffer skull is useful to delineate the phenotypic changes required for correction, can help surgeons plan reconstructive surgery and is a potentially promising surgical outcome measure.


Asunto(s)
Acrocefalosindactilia/clasificación , Disostosis Craneofacial/clasificación , Análisis de Componente Principal , Acrocefalosindactilia/diagnóstico por imagen , Adolescente , Puntos Anatómicos de Referencia/diagnóstico por imagen , Estudios de Casos y Controles , Cefalometría/métodos , Niño , Disostosis Craneofacial/diagnóstico por imagen , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Masculino , Películas Cinematográficas , Planificación de Atención al Paciente , Fenotipo , Procedimientos de Cirugía Plástica/métodos , Cráneo/patología , Tomografía Computarizada Espiral/métodos , Interfaz Usuario-Computador
20.
J Plast Reconstr Aesthet Surg ; 67(6): e151-61, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24709088

RESUMEN

UNLABELLED: Apert syndrome is a congenital disorder characterized by craniosynostosis and midface hypoplasia. This study looks to identify to what extent bipartition distraction corrects the morphological abnormalities of this condition. Preoperative and postoperative three-dimensional computed tomography (3DCT) scans of 10 patients with Apert syndrome (12-21 years) were identified from the Great Ormond Street Hospital database. To analyse preoperative and postoperative scans, 98 landmarks and 13 normal skulls were used. Principal component analysis (PCA) was used to analyse patterns in the datasets. Within each group, eigenvectors were identified that demonstrated the aspects of the skull where most variations were found. The analysis allowed both global shape measurement and local proportions. Postoperative and normal scans both showed the same first three principal components. Warping from preoperative to postoperative illustrates midface advancement and inward rotation of the orbits. Postoperative to normal warps demonstrate some remaining differences. The reliability of the used land marks varied between 77% and 95% for the highly reproducible landmarks between the two observers. 95% versus 100% were at least acceptable reproducible landmarks. This study allows us to understand the way bipartition distraction corrects the abnormalities of the Apert skull. Analysing the surgical outcome of facial bipartition with geometric morphometrics shows that some major Apert characteristics are corrected. Using the data and the output of further studies, surgical procedures can be adapted in order to achieve a postoperative result closer to the normal population. LEVEL OF EVIDENCE: Therapeutic clinical question Level IV.


Asunto(s)
Acrocefalosindactilia/diagnóstico por imagen , Acrocefalosindactilia/cirugía , Huesos Faciales/diagnóstico por imagen , Imagenología Tridimensional/métodos , Tomografía Computarizada Multidetector/métodos , Interpretación de Imagen Radiográfica Asistida por Computador , Acrocefalosindactilia/diagnóstico , Adolescente , Puntos Anatómicos de Referencia , Estudios de Casos y Controles , Cefalometría/métodos , Niño , Huesos Faciales/anomalías , Huesos Faciales/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Osteogénesis por Distracción/métodos , Cuidados Posoperatorios/métodos , Cuidados Preoperatorios/métodos , Procedimientos de Cirugía Plástica/métodos , Reproducibilidad de los Resultados , Resultado del Tratamiento
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