Christopher R Forrest

SickKids, Toronto, Ontario, Canada

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Publications (115)247.1 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective : To investigate the stability of major versus minor Le Fort I maxillary advancements in unilateral cleft lip and palate (UCLP) patients. Design : A retrospective longitudinal study was undertaken on 30 nonsyndromic UCLP patients treated with the same protocol at The Hospital for Sick Children, Toronto, Canada. Patients were grouped into major and minor movement groups based on planned surgical advancement. Standard lateral cephalometric radiographs were taken preoperatively (T1), immediately postoperatively (T2), and at least 1 year postoperatively (T3). Skeletal and dental variables were measured using cephalometric analysis. Stability was compared between groups using repeated-measures analysis of variance. Linear regression analysis was used to assess the relationship between advancement and relapse for the entire study population. Results : A mean maxillary advancement of 9.8 mm and 4.9 mm was seen for the major (n = 10) and minor (n = 20) movement groups, respectively. The mean skeletal horizontal relapse was 1.8 mm (18%) for the major advancement group and 1.5 mm (31%) for the minor advancement group. There was no significant difference in skeletal horizontal relapse between the groups (P > .05). The correlation coefficient (r) between linear horizontal advancement and relapse was calculated to be .31 (P > .05). Dental horizontal relapse was not significant for either the major or minor groups, and no significant difference was found between the groups (P > .05). Conclusion : Skeletal and dental relapse was found to be unrelated to the amount of maxillary linear advancement using conventional Le Fort I osteotomies in UCLP.
    The Cleft Palate-Craniofacial Journal 09/2014; DOI:10.1597/14-061.1 · 1.24 Impact Factor
  • Journal of Oral and Maxillofacial Surgery 09/2014; 72(9):e46-e47. DOI:10.1016/j.joms.2014.06.078 · 1.28 Impact Factor
  • Journal of Oral and Maxillofacial Surgery 09/2014; 72(9):e23. DOI:10.1016/j.joms.2014.06.040 · 1.28 Impact Factor
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    ABSTRACT: Hemifacial microsomia is a hypoplastic disorder of the first and second branchial arches that significantly impacts on the development of the jaws, leading to malocclusion and facial asymmetry. There is little in the literature regarding the application of orthodontic/orthognathic approaches to the correction of these deformities and the stability of the surgical results. To address this, a retrospective chart review of 10 patients with complete orthodontic records and greater than 1 year of follow-up was performed. Posteroanterior cephalograms were assessed by modified Grummons analysis to determine mandibular offset (deviation of the chin point from the skeletal midline) and occlusal cant. These measurements were performed at 3 time points (T1: preoperative, T2: immediate postoperative, T3: follow-up) to elucidate the surgical movement (T2-T1), the postoperative relapse (T3-T2), and the net gain movement (T3-T1). Maxillary movements were quantified, and the occlusal cant was expressed as a ratio between vertical heights of the maxilla at the first molar on each side. One sample t test demonstrated statistically significant surgical movement and net gain. Relapse was statistically insignificant. Repeated-measures analysis of variance demonstrated similar results for chin point position relative to the putative midline. Our results suggest that a combined orthodontic/orthognathic approach at skeletal maturity delivers improved occlusal outcomes in the long term as assessed by chin point deviation and occlusal cant, but secondary surgery rates are higher than those for orthognathic surgery in other patient groups. We advocate limiting surgery to skeletal maturity whenever possible to achieve stable long-term results while limiting morbidity and number of procedures.
    Journal of Craniofacial Surgery 07/2014; 25(5). DOI:10.1097/01.SCS.0000435808.91512.58 · 0.68 Impact Factor
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    ABSTRACT: Purpose To investigate the stability of single piece versus segmental (2-piece) maxillary advancement in unilateral cleft lip and palate (UCLP) patients treated using conventional Le Fort I orthognathic surgery. Methods A retrospective study was undertaken on 30 non-syndromic UCLP patients treated with the same surgical and orthodontic protocol between 2002 and 2011. Standard lateral cephalometric radiographs were taken preoperatively, immediately postoperatively, and at least 1 year postoperatively. Patients were divided into single piece and segmental Le Fort I groups based on planned surgical movement. Postoperative movements were compared between groups using repeated measure analysis of variance. Results The mean skeletal horizontal advancement was 7.3 and 7.5mm in the single piece and segmental groups, respectively. The skeletal horizontal relapse was 1.3mm (18%) for the single piece group and 1.9mm (25%) for the segmental group. The skeletal surgical extrusion was 2.7mm for both groups. The skeletal vertical relapse was 0.6mm (22%) and 1.5mm (56%) for the single piece and segmental groups, respectively. The mean dental horizontal postoperative movement for the single piece group was advancement of 0.4mm and for the segmental group a relapse of 0.2mm (3%). The mean dental vertical relapse was 0.1mm (4%) for the single piece and 0.3mm (11%) for the segmental group. There was no statistically significant difference in relapse between the single and segmental groups for all movements (p>0.05). Conclusion Skeletal and dental relapse was similar between single piece and segmental maxillary advancements using conventional Le Fort I orthognathic surgery in UCLP patients.
    Journal of Oral and Maxillofacial Surgery 07/2014; DOI:10.1016/j.joms.2014.07.005 · 1.28 Impact Factor
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    ABSTRACT: Recent reports of directed reprogramming have raised questions about the stability of cell lineages. Here, we have addressed this issue, focusing upon skin-derived precursors (SKPs), a dermally derived precursor cell. We show by lineage tracing that murine SKPs from dorsal skin originate from mesenchymal and not neural crest-derived cells. These mesenchymally derived SKPs can, without genetic manipulation, generate functional Schwann cells, a neural crest cell type, and are highly similar at the transcriptional level to Schwann cells isolated from the peripheral nerve. This is not a mouse-specific phenomenon, since human SKPs that are highly similar at the transcriptome level can be made from neural crest-derived facial and mesodermally derived foreskin dermis and the foreskin SKPs can make myelinating Schwann cells. Thus, nonneural crest-derived mesenchymal precursors can differentiate into bona fide peripheral glia in the absence of genetic manipulation, suggesting that developmentally defined lineage boundaries are more flexible than widely thought.
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    ABSTRACT: The purpose of this study is 2-fold: (1) to identify computed tomography (CT)-based morphometric parameters that differentiate the normal skull from one with sagittal synostosis and (2) to evaluate correction of sagittal synostosis with extended strip craniectomy and postoperative helmeting based on morphometric parameters. An institutional review board-approved, retrospective review was carried out at the Hospital for Sick Children for all patients who underwent an extended strip craniectomy and postoperative helmeting for sagittal synostosis from 1999 to 2005. Inclusion criteria consisted of patients who underwent a routine craniofacial CT preoperatively and 12 months postoperatively. Craniofacial CT scans of age-matched control subjects were used for preoperative and postoperative comparison. Thirty-nine patients with sagittal synostosis met inclusion criteria. Median age at preoperative CT was 3.0 months. Nine control subjects were identified, with a median age at CT scan of 5.0 months. Patients with sagittal synostosis preoperatively had a significantly longer maximum cranial length, smaller maximum cranial breadth, more acute frontal takeoff and occipital incline angles, lower cephalic index, and an anteriorly positioned vertex. Postoperative CT scans (median, 17.0 months) were compared with 10 control subjects (median, 19.0 months). Patients with sagittal synostosis postoperatively had equivalent maximum cranial breadth, frontal takeoff, and occipital incline angles as compared with controls. Sagittal synostosis patients remained with a significantly longer maximum cranial length, lower cephalic index, and anteriorly positioned vertex. Twelve months following extended strip craniectomy and helmeting for sagittal synostosis, CT-based morphometric analysis demonstrated correction of cranial breadth, frontal bossing, and occipital bulleting. Skull length and vertex position did not fully correct.
    The Journal of craniofacial surgery 01/2014; 25(1):42-7. DOI:10.1097/SCS.0000000000000478 · 0.68 Impact Factor
  • Plastic &amp Reconstructive Surgery 01/2014; 133:166-167. DOI:10.1097/01.prs.0000444978.37313.56 · 3.33 Impact Factor
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    ABSTRACT: Although symmetry is hailed as a fundamental goal of aesthetic and reconstructive surgery, our tools for measuring this outcome have been limited and subjective. With the advent of three-dimensional photogrammetry, surface geometry can be captured, manipulated, and measured quantitatively. Until now, few normative data existed with regard to facial surface symmetry. Here, we present a method for reproducibly calculating overall facial symmetry and present normative data on 100 subjects. We enrolled 100 volunteers who underwent three-dimensional photogrammetry of their faces in repose. We collected demographic data on age, sex, and race and subjectively scored facial symmetry. We calculated the root mean square deviation (RMSD) between the native and reflected faces, reflecting about a plane of maximum symmetry. We analyzed the interobserver reliability of the subjective assessment of facial asymmetry and the quantitative measurements and compared the subjective and objective values. We also classified areas of greatest asymmetry as localized to the upper, middle, or lower facial thirds. This cluster of normative data was compared with a group of patients with subtle but increasing amounts of facial asymmetry. We imaged 100 subjects by three-dimensional photogrammetry. There was a poor interobserver correlation between subjective assessments of asymmetry (r = 0.56). There was a high interobserver reliability for quantitative measurements of facial symmetry RMSD calculations (r = 0.91-0.95). The mean RMSD for this normative population was found to be 0.80 ± 0.24 mm. Areas of greatest asymmetry were distributed as follows: 10% upper facial third, 49% central facial third, and 41% lower facial third. Precise measurement permitted discrimination of subtle facial asymmetry within this normative group and distinguished norms from patients with subtle facial asymmetry, with placement of RMSDs along an asymmetry ruler. Facial surface symmetry, which is poorly assessed subjectively, can be easily and reproducibly measured using three-dimensional photogrammetry. The RMSD for facial asymmetry of healthy volunteers clusters at approximately 0.80 ± 0.24 mm. Patients with facial asymmetry due to a pathologic process can be differentiated from normative facial asymmetry based on their RMSDs. Diagnostic, II.
    The Journal of craniofacial surgery 01/2014; 25(1):124-8. DOI:10.1097/SCS.0b013e3182a2e99d · 0.68 Impact Factor
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    ABSTRACT: Cranio-orbital reshaping for anterior cranial-vault deformities associated with craniosynostosis traditionally relies on the surgeon's subjective estimate of the shape and appearance of a normal forehead. Computer-aided design/computer-aided manufacture (CAD/CAM) bandeau templates to guide reconstruction were introduced in our centre to eliminate this subjectivity and to effect more reproducible surgical results. The aim of this study was to compare two groups of patients (template, n = 14 vs. no template, n = 23) to measure surgical outcomes. The virtual, computational version of the template was used as an outcome assessment tool. It was used to calculate an intervening area under the curve (AUC) between the normative template and the patient's reconstructed supra-orbital bar on a representative computed tomography (CT) axial section. A comprehensive chart review was conducted of patients in both groups to examine the preoperative and postoperative variables. Based on the analysis performed on the immediate postoperative CT scans, in the template group - as compared to the control, no-template group - the use of the bandeau template led to a greater reduction in AUC (74% vs. 56%, p = 0.016), indicating a better conformity between the reconstructed supra-orbital bar and the ideal, normal bandeau shape. The duration of operation was significantly reduced with the use of the template (212 vs. 258 min, p < 0.001). The application of prefabricated templates in cranio-orbital reshaping is highly useful for accurate preoperative planning; reproducible and efficient intra-operative correction of dysmorphology; and objective surgical outcomes assessment. Therapeutic Level III.
    Journal of Plastic Reconstructive & Aesthetic Surgery 09/2013; 67(1). DOI:10.1016/j.bjps.2013.09.009 · 1.47 Impact Factor
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    ABSTRACT: Craniofacial fibrous dysplasia is a benign developmental anomaly in which normal bone is replaced by fibro-osseous tissue. The aim of this study was to audit the patient population at a tertiary paediatric centre and report our treatment protocols. A retrospective chart review of all patients with craniofacial fibrous dysplasia treated at the Hospital for Sick Children between 1999 and 2010 was performed. The treatment algorithm used by our centre is presented. A total of 55 patient records were reviewed; 37 patients had sufficient documentation for study; 27 (16 male, 11 female) patients underwent surgery at our institution, of these patients, 26 had post-operative follow up of greater than one year (mean 41 months; median 24 months). Mean age at presentation was 9.9 years (median 10 years) and mean age of surgery was 13 years. Ten patients underwent surgery on the fronto-orbital region, 7 of the calvarium, 2 the skull base and 8 upon tooth-bearing bones. Fourteen cases underwent debulking surgery as their primary therapy whereas 13 patients had complete resection. Nine patients experienced recurrence and all but one case of these occurred in patients that underwent debulking therapy. When age of surgery is considered, total resection and reconstruction or debulking surgery after skeletal maturity has a lower recurrence rate (1/7 cases) than earlier surgery (8/16). Complete resection at any age and debulking surgery once skeletal maturity has been reached may be associated with lower recurrence rates than incomplete resections at an earlier age. Patients with McCune-Albright syndrome may benefit from repeated debulking procedures rather than complex resections and reconstructions.
    Journal of Plastic Reconstructive & Aesthetic Surgery 07/2013; 66(10). DOI:10.1016/j.bjps.2013.05.031 · 1.47 Impact Factor
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    ABSTRACT: This article discusses the measurement of outcomes in craniofacial and pediatric plastic surgery, using examples of craniosynostosis and cleft lip and/or palate (CLP). The challenges in measuring the standard outcomes of function, aesthetics, and health-related quality of life are discussed, along with the importance of developing evidence and studying quality improvement in this specialty. The need to define specific and comprehensive goals is discussed with a focus on patient-reported outcomes (PROs). Examples from the development of the CLEFT-Q, a PRO instrument for patients with CLP, are provided to support the need to seek the patient perspective.
    Clinics in plastic surgery 04/2013; 40(2):305-312. DOI:10.1016/j.cps.2012.11.005 · 1.35 Impact Factor
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    ABSTRACT: : In autogenous muscle transplantation, unpredictable complications can cause prolonged ischemia, resulting in ischemia-reperfusion injury. The authors investigated the efficacy and mechanism of nicorandil, a nitrovasodilator and adenosine triphosphate-sensitive potassium channel opener, in inducing perioperative protection of muscle flaps from ischemia-reperfusion injury. : Pigs (18.2 ± 2.4 kg) were assigned to one control and eight treatment groups. Bilateral latissimus dorsi muscle flaps were raised after saline administration (control) and 0, 4, 8, 12, 24, 48, 72, and 96 hours after nicorandil administration. Subsequently, flaps were subjected to 4 hours of ischemia and 48 hours of reperfusion. Viability was assessed, and biochemical probes were used to study nicorandil-induced infarct protection. : Protection by nicorandil was biphasic. Infarction reduced from 40.2 ± 1.9 percent (control) to 27.3 ± 1.7 percent and 24.0 ± 2.3 percent (p < 0.05) 0 and 4 hours after nicorandil administration, respectively (early phase protection). No difference was seen between control and treatment groups between 8 and 12 hours after nicorandil administration compared with the control. Infarct protection increased again (p < 0.05) at 24 (22.4 ± 2.0 percent), 48 (25.1 ± 2.1 percent), and 72 hours (28.5 ± 2.1 percent) but not at 96 hours (43.9 ± 4.6 percent) compared with control (late phase protection). The sarcolemmal and mitochondrial channels played a central role in the trigger and mediator mechanisms, respectively. Late protection was associated with lower myeloperoxidase activity and mitochondrial calcium overload and higher adenosine triphosphate content (p < 0.05). : Nicorandil induced 48-hour uninterrupted muscle infarct protection, starting 24 hours after intravenous administration. This category of clinical drug is a potential prophylactic treatment against skeletal muscle ischemia-reperfusion injury in reconstructive surgery.
    Plastic and Reconstructive Surgery 03/2013; 131(3):473-85. DOI:10.1097/PRS.0b013e31827c6e0b · 3.33 Impact Factor
  • Plastic &amp Reconstructive Surgery 01/2013; 131:105. DOI:10.1097/01.prs.0000430080.26061.ec · 3.33 Impact Factor
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    ABSTRACT: Deformational plagiocephaly (DP) is a multifactorial non-synostotic cranial deformity with a reported incidence as high as 1 in 7 infants in North America. Treatment options have focused on non-operative interventions including head repositioning and the use of an orthotic helmet device. Previous studies have used linear and two dimensional outcome measures to assess changes in cranial symmetry after helmet therapy. Our objective was to demonstrate improvement in head shape after treatment with a cranial molding helmet by using Root Mean Square (RMS), a measure unique to 3D photogrammetry, which takes into account both changes in volume and shape over time. Three dimensional photographs were obtained before and after molding helmet treatment in 40 infants (4–10 months old) with deformational plagiocephaly. Anatomical reference planes and measurements were recorded using the 3dMD Vultus® analysis software. RMS was used to quantify symmetry by superimposing left and right quadrants and calculating the mean value of aggregate distances between surfaces. Over 95% of the patients demonstrated an improvement in symmetry with helmet therapy. Furthermore, when the sample of infants was divided into two treatment subgroups, a statistically significant correlation was found between the age at the beginning of treatment and the change in the RMS value. When helmet therapy was started before 7 months of age a greater improvement in symmetry was seen. This work represents application of the technique of RMS analysis to demonstrate the efficacy of treatment of deformational plagiocephaly with a cranial molding helmet.
    Journal of Plastic Reconstructive & Aesthetic Surgery 01/2013; 67(2). DOI:10.1016/j.bjps.2013.09.036 · 1.47 Impact Factor
  • Christopher R Forrest, Richard A Hopper
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    ABSTRACT: LEARNING OBJECTIVES:: After studying this article, the participant should be able to: 1. Understand craniofacial dysmorphology and identify basic pediatric craniofacial syndromes. 2. Understand the functional concerns associated with these syndromes. 3. Achieve familiarity with the management protocols for the treatment of pediatric craniofacial syndromes. SUMMARY:: This article provides an overview of the diagnosis and management of infants and children with craniofacial syndromes. Treatment protocols from The Hospital for Sick Children, Toronto, Ontario, Canada, and Seattle Children's Hospital, Seattle, Washington, are highlighted.
    Plastic and Reconstructive Surgery 01/2013; 131(1):86e-109e. DOI:10.1097/PRS.0b013e318272c12b · 3.33 Impact Factor
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    ABSTRACT: We previously demonstrated that hypoxic preconditioning (HPreC) or postconditioning (HPostC) protected ex vivo human skeletal muscle from hypoxia/reoxygenation injury. Here, we investigated if combined HPreC and HPostC could convey additive protection. Human rectus abdominis muscle strips were cultured in normoxic Krebs buffer for 5 hours (control) or in 3 hours hypoxic/2 hours normoxic buffer (treatment groups). HPreC and HPostC were induced by 1 cycle of 5 minutes hypoxia/5 minutes reoxygenation immediately before or after 3 hours hypoxia, respectively. Muscle injury, viability, and adenosine triphosphate (ATP) synthesis were assessed by measuring lactate dehydrogenase release, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide reduction, and ATP content, respectively. Hypoxia/reoxygenation caused lactate dehydrogenase to increase and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide reduction and ATP content to decrease (P < 0.05; n = 7). HPreC, HPostC, and combination of both were equally effective in protection of muscle from hypoxia/reoxygenation injury. Atractyloside (5 × 10 M), a mitochondrial permeability transition pore opener, abolished the protective effect of HPreC or HPostC. We conclude that HPreC and HPostC protect ex vivo human skeletal muscle against hypoxia/reoxygenation injury by closing the mitochondrial permeability transition pore. For that reason, they are equally effective and do not demonstrate an additive effect. Moreover, the potent effect of HPostC indicates ischemic postconditioning as an effective clinical intervention against reperfusion injury in autogenous skeletal muscle transplantation and replantation surgery.
    Journal of cardiovascular pharmacology 06/2012; 60(4):347-56. DOI:10.1097/FJC.0b013e318262c961 · 2.11 Impact Factor
  • Kim Tiemens, David B Nicholas, Christopher R Forrest
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    ABSTRACT: Abstract Objective: This study explored the experiences of adolescent girls with cleft lip and palate who were preparing for orthognathic surgery. Design: A qualitative study, based on a phenomenological approach, explored adolescents' experiences. Two one hour long semi-structured interviews were conducted before surgery, and member checking was employed to verify findings with each participant. Setting: A tertiary care pediatric hospital in central Canada. Participants: A criterion sampling technique was used to recruit a sample of seven participants with cleft lip and palate ranging in age from 15 to 20 years who were scheduled for cleft orthognathic surgery. Results: Participants described experiencing teasing, bullying and stares. In many cases, participants sought to resist and dismiss negative social attitudes about their visible difference while working to combat this with a positive view of who they really are. To varying degrees, participants felt constricted in engaging in the community as they were worried what others thought of their visible difference. They worked at finding ways to reduce the impact of social stigma through coping strategies, social supports and reconstructive surgery. Conclusions: Adolescent girls can experience strain associated with living with a facial difference; however, they find strategies to cope with the perception of difference. Reconstructive surgery is viewed as a means to increase confidence. Further intervention is needed in understanding and addressing stigma and fostering resiliency related to female adolescents living with a facial difference. Key Words: craniofacial, cleft lip and palate, adolescents, qualitative research, orthognathic surgery, social stigma.
    The Cleft Palate-Craniofacial Journal 05/2012; DOI:10.1597/10-278 · 1.11 Impact Factor
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    ABSTRACT: The authors previously established an animal model of radiation-induced craniofacial bone growth inhibition and demonstrated the effectiveness of cytoprotection in preserving growth using amifostine, but the mechanism is unclear. The objective of this study was to investigate the acute and long-term histopathologic effects of single-dose orthovoltage irradiation on craniofacial bone with and without cytoprotection. Sixty infant New Zealand White rabbits (7-week-old) were randomized into three groups (n = 20 per group): group 1, 0-Gy, sham irradiation; group 2, 35-Gy single-dose orthovoltage irradiation; and group 3, cytoprotection with amifostine before irradiation. Orbitozygomatic complex bone was harvested from animals 12 hours after irradiation and at skeletal maturity (21 weeks of age). Histologic parameters measured included native bone cell (osteoblast, osteoclast, and osteocyte) populations, periosteal proliferation indices (MIB-1 stains), bone turnover rates [triple fluorochromes: tetracycline administered at 7 weeks of age (before irradiation), alizarin complexone at 12 weeks, and calcein at 16 weeks of age], and endosteal space fibrosis levels. Orthovoltage irradiation significantly (p < 0.05) reduced osteoblast and osteoclast counts 12 hours after irradiation (age, 7 weeks) with or without pretreatment with amifostine but had no effect on osteocyte populations. Long-term analysis at age 21 weeks demonstrated significantly (p < 0.05) increased osteoblast counts, reduced endosteal space fibrosis, reduced periosteal proliferation indices, and improved bone turnover (fluorochrome stains) in amifostine-treated animals. This study suggests that amifostine cytoprotection is mediated through a combination of reduced cellular injury with enhanced promotion of cellular bone rebuilding potential.
    Plastic and Reconstructive Surgery 04/2012; 129(4):636e-45e. DOI:10.1097/PRS.0b013e31824421b6 · 3.33 Impact Factor

Publication Stats

2k Citations
247.10 Total Impact Points

Institutions

  • 1988–2014
    • SickKids
      • • Program in Neurosciences and Mental Health (NMH)
      • • Division of Plastic Surgery
      • • Department of Surgery
      Toronto, Ontario, Canada
  • 1987–2014
    • University of Toronto
      • • Department of Surgery
      • • Hospital for Sick Children
      Toronto, Ontario, Canada
  • 2011
    • Case Western Reserve University School of Medicine
      Cleveland, Ohio, United States
  • 1993
    • St. Michael's Hospital
      Toronto, Ontario, Canada
  • 1991–1993
    • Sunnybrook Health Sciences Centre
      • Department of Plastic Surgery
      Toronto, Ontario, Canada