David Dunaway

A 3D Morphable Model Learnt from 10,000 Faces

We present Large Scale Facial Model (LSFM) - a 3D Morphable Model (3DMM) automatically constructed from 9,663 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. The dataset that LSFM is trained on includes rich demographic information about each subject, allowing for the construction of not only a global 3DMM but also models tailored for specific age, gender or ethnicity groups. As an application example, we utilise the proposed model to perform age classification from 3D shape alone. Furthermore, we perform a systematic analysis of the constructed 3DMMs 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. In addition, the constructed global 3DMM and a variety of bespoke models tailored by age, gender and ethnicity are available on application to researchers involved in medically oriented research.

Raised intracranial pressure in Apert syndrome.

Background: Raised intracranial pressure is a well-known complication of Apert syndrome. The current policy in the authors’ unit is to monitor these patients and only perform surgery when raised intracranial pressure has been diagnosed. The authors present their experience with this protocol, as it allows a more accurate picture of the natural history of raised intracranial pressure in Apert syndrome. Methods: The records of 24 patients, aged between 7 and 14 years, with Apert syndrome who had been managed expectantly (i.e., with no routine “automatic” early surgery) were reviewed. Data were collected on the incidence, timing, and management of raised intracranial pressure. Results: Twenty of 24 patients (83 percent) developed raised intracranial pressure. The average age of the first episode was 18 months (range, 1 month to 4 years 5 months). Raised intracranial pressure was managed with surgery in 18 patients, including two patients who underwent shunt procedures for hydrocephalus. Two patients had their raised intracranial pressure treated successfully by correcting coexisting upper airway obstruction alone. Seven of the 20 patients (35 percent) developed a second episode of raised intracranial pressure, on average 3 years 4 months later (range, 1 year 11 months to 5 years 9 months). Conclusions: In Apert syndrome, there is a high incidence of raised intracranial pressure, which can first occur at any age up to 5 years and may recur despite initial successful treatment. Causes of raised intracranial pressure include craniocerebral disproportion, venous hypertension, upper airway obstruction, and hydrocephalus. Careful clinical, ophthalmologic, respiratory, and radiologic monitoring will allow raised intracranial pressure to be diagnosed accurately when it occurs and then treated most appropriately.

Functional outcomes in monobloc advancement by distraction using the rigid external distractor device.

Background: Craniofacial dysostosis syndromes produce multisutural synostoses combined with severe midfacial retrusion. This may cause serious functional problems, including airway obstruction, exposure of the eyes, visual pathway dysfunction, and raised intracranial pressure. Early midface advancement may be necessary to address these issues. Distraction osteogenesis has provided the facility to achieve significant advances safely and is often in excess of that which is achievable by conventional means. Methods: A retrospective study of 20 patients with craniofacial dysostosis and severe midface hypoplasia who underwent monobloc advancement osteotomies using the rigid external distractor system principally for functional reasons was undertaken. The multidisciplinary management and outcome measures of these patients were recorded. Results: The midface was distracted an average of 16.4 mm, with a range of 12 to 22 mm. Ocular protection was achieved in all patients with preoperative exposure keratopathy and/or globe subluxation. Improvements in optic disc swelling and pattern visually evoked potentials were seen in those patients with threatened visual impairment. Improvement in airway obstruction was seen in those patients with abnormal polysomnography. Decannulation was achieved in five of the seven patients with tracheostomies. Fifty percent had a reduction in hyponasality, and the visual appearance of speech was improved. Complications included persistent cerebrospinal fluid leakage, acquired hypernasality in 25 percent, cranial bone loss, and sinus formation requiring surgical revision. Conclusions: Monobloc distraction osteogenesis results in good aesthetic and functional outcomes. The relatively high rate of complications remains a concern, and further adaptations of technique are needed to reduce the risks of this procedure.

Spectrum of Antley-Bixler syndrome.

Antley-Bixler syndrome (ABS) is an exceptionally rare craniosynostosis syndrome characterized by radiohumeral synostosis present from the perinatal period. There is a wide spectrum of anomalies seen within ABS, and other features include midface hypoplasia; choanal stenosis or atresia; multiple joint contractures; visceral anomalies, particularly of the genitourinary system; and impaired steroidogenesis.The condition of ABS is curious in that mutations of 2 separate genes have been identified and that there seem to be subtle phenotypic differences between the 2 genotypes. Mutations of the P450 oxidoreductase gene have been reported in those patients with genital anomalies and/or impaired steroidogenesis, and the S351C mutation of the fibroblast growth factor receptor 2 gene has been reported predominantly in those patients with normal genitalia and steroidogenesis. We report a series of 4 patients with ABS and review their main findings and management.

Mandibular reconstruction in the growing patient with unilateral craniofacial microsomia: a systematic review

The purpose of this systematic review is to provide an overview of the surgical correction of the mandible in unilateral craniofacial microsomia (UCM) performed in the growing patient, and its long-term outcome and stability. The following databases were searched: PubMed, Embase, Cochrane, and Web of Science. Articles reporting prospective and retrospective studies of patients not older than 16 years (N ≥ 4) who had undergone surgical correction of a craniofacial microsomia spectrum condition using grafts, osteotomies, distraction, or combinations of these, were reviewed. The period of follow-up was selected to be ≥1 year. After inclusion, the articles were evaluated on short- and long-term outcomes, relapse, and any increase in asymmetry following treatment. Thirty of 1611 articles were included in the qualitative synthesis. Analysis of the surgical mandibular correction of UCM showed that the outcome is not so much treatment-dependent, but patient-dependent, i.e. deformity gradation-dependent. The type I-IIa Pruzansky-Kaban patient had the best results with regard to minimal relapse and/or minimal increase in asymmetry. Single-stage correction of the asymmetry should be postponed until the permanent dentition stage. It can be concluded that in the treatment of the severely hypoplastic mandible, the patient will benefit from a multi-stage treatment protocol if indicated for functional or psychological problems.

Frontofacial monobloc distraction in the very young: a review of 12 consecutive cases

Background: Frontofacial monobloc advancement by distraction osteogenesis is now accepted as an effective treatment for children with syndromic and other complex forms of craniosynostosis because it combines cosmetic advantages with the ability to treat such complications as raised intracranial pressure, advancing exorbitism, and upper airway obstruction in one procedure. In the severely affected child, these complications may be present at an early age, but because of the scale of monobloc surgery, surgeons have been reluctant to perform it on very young children. Methods: The authors report a series of 12 children younger than 30 months with various craniosynostosis-associated syndromes complicated by multiple functional problems—including raised intracranial pressure, exposure of the eyes, airway obstruction, and feeding problems—who underwent frontofacial monobloc surgery by distraction osteogenesis. Results: The mean age at operation was 18 months. Mean advancement achieved was 16.6 mm for the upper face and 17 mm for the midface. Ocular protection and reduction of intracranial pressure (when raised) were achieved in all children. Airway improvement was achieved in all but one child. Although not the primary indication for surgery, there was also a marked improvement in every patients appearance. Complications included two cerebrospinal fluid leaks, pin-site infections, frame slippage requiring replacement, and enophthalmos in one patient. Conclusion: The frontofacial monobloc advance incorporating distraction osteogenesis can be undertaken with acceptable morbidity even in the very young child and good functional outcomes achieved with one operation where previously more were required. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Three-dimensional image analysis of facial skeletal changes after monobloc and bipartition distraction.

Background: Both monobloc and facial bipartition distraction are important tools for correcting functional and aesthetic problems in patients with syndromic craniosynostosis. Three-dimensional computed tomographic reconstructions have become increasingly useful in planning and analyzing surgical results. This study measured the differential deformation of the facial skeleton following distraction osteogenesis with the rigid external distractor frame, looking especially at correction of the midface concavity. Correction of the midface concavity aims to not only improve the appearance but also increase the upper airway volume. Methods: Ten children with syndromic craniosynostoses were studied. Seven children with Crouzon syndrome underwent monobloc distraction and three with Apert syndrome underwent facial bipartition distraction using the rigid external distractor frame. The patients’ ages ranged from 4 months to 15 years. The medial advancement and the lateral advancement of the facial skeleton were compared by landmarking three-dimensional computed tomographic reconstructions using the sella turcica as the fixed point. To compare the shape of the monobloc segment from the preoperative to postoperative scans, a color map was generated. Results: Of the seven patients who underwent monobloc distraction, the mean medial advancement of the face was 4.9 mm greater than the lateral advancement. With the bipartition distraction, the mean central area advancement was 11.4 mm farther than the lateral aspect of the facial skeleton. Conclusions: Both monobloc and in particular the facial bipartition distraction differentially advance the central part of the face more than the lateral areas. This bending of the face appears to have both cosmetic and functional advantages.

Adverse events of local treatment in long-term head and neck rhabdomyosarcoma survivors after external beam radiotherapy or AMORE treatment

BACKGROUND Radiotherapy is a well-known cause of adverse events (AEs). To reduce AEs, an innovative local treatment was developed in Amsterdam: Ablative surgery, MOuld brachytherapy and surgical REconstruction (AMORE). AIMS (1) to determine the prevalence of AEs in HNRMS survivors and (2) to compare AEs between survivors treated with the international standard: external beam radiotherapy (EBRT-based: London) and survivors treated with AMORE if feasible, otherwise EBRT (AMORE-based: Amsterdam). METHODS All HNRMS survivors, treated in London or Amsterdam between January 1990 and December 2010 (n = 153), and alive ⩾ 2 years post-treatment were eligible (n = 113). A predefined list of AEs was assessed in a multidisciplinary clinic and graded according to the Common Terminology Criteria for Adverse Events. RESULTS Eighty HNRMS survivors attended the clinic (median follow-up 10.5 years); 63% experienced ⩾ 1 severe or disabling event, and 76% had ⩾ 5 AEs (any grade). Survivors with EBRT-based treatment were, after adjustment for site, age at diagnosis, and follow-up duration, at increased risk to develop any grade 3/4 event or ⩾ 5 AEs (any grade) compared with survivors with AMORE-based treatments (p = 0.032 and 0.01, respectively). Five year overall survival (source population) after EBRT-based treatment was 75.0%, after AMORE-based treatment 76.9%, p = 0.56. CONCLUSION This study may serve as a baseline inventory and can be used in future studies for prospective assessments of AEs following the introduction of novel local treatment modalities. AMORE-based local treatment resulted in similar overall survival and a reduction of AEs secondary to local treatment.

Describing Crouzon and Pfeiffer syndrome based on principal component analysis

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.

Midface osteotomy versus distraction: The effect on speech, nasality, and velopharyngeal function in craniofacial dysostosis

Objective: To assess speech outcomes following midface advancement and to explore whether the type of advancement surgery affects speech differently in patients with craniofacial dysostosis. Design: Prospective, before-after group design. Subjects: Fifteen consecutive patients were included in the study. Eight underwent advancement by osteotomy and seven by distraction. All patients were seen preoperatively and at least once postoperatively. Main Outcome Measures: Percentage of consonants correct, nature and type of articulation errors, nasalance score, severity ratings of resonance and of velopharyngeal function using nasendoscopy and lateral videofluoroscopy, and amount of forward advancement. Results: No statistically significant differences were found between groups for pre- and postoperative changes of percentage of consonants correct (p  =  .755, median difference 3.0, 95% confidence interval for median difference [−14.22, 20.22]) and nasalance (p  =  .171, median difference  =  −12.00, 95% confidence interval for median differences [−30.46, 6.46]). There was no statistically significant correlation between amount of forward advancement and nasalance (r  =  .87, p  =  .799) and percentage of consonants correct (r  =  −.550, p  =  .064). Findings from lateral videofluoroscopy and nasendoscopy are described. Individual changes of speech outcomes are reported. Conclusions: In view of the small sample size, results need to be interpreted with caution. However, the study adds to current limited knowledge with this clinical group. Further research with bigger sample sizes and randomization of patients into the different surgical groups is warranted.