Hyoid bone morphology in patients with isolated robin sequence - A case-control study utilizing 3D morphable models.

Background: Abnormalities of the hyoid bone are associated with impairment of oropharyngeal functions including feeding, swallowing, and breathing. Few studies have characterized anatomic abnormalities of the hyoid in patients with Robin sequence (RS), e.g. a less mineralized and voluminous hyoid. The purpose of this study was to compare normal hyoid bone morphology and hyoid bone morphology in children with isolated RS. Methods: Three-dimensional (3D) reconstructions of the hyoid bone were obtained from CT-imaging of children with RS and unaffected controls. A 3D morphable model was constructed using Principal Component Analysis (PCA). Partial least squares - Discriminant Analysis (PLS-DA) and multivariate analysis of variance (MANOVA) were used to characterize and compare hyoid shape differences between patients with RS and an age-matched control group. Results: The study included 23 subjects with RS (mean age 9.8 ± 10.3 months) and 46 age-matched control samples. A less voluminous hyoid was observed for the RS group with a larger lateral divergence of the greater horns compared to controls (MANOVA, p-value<0.001). The first shape variable from the PLS-DA model showed a significant correlation for the observed variance between the two groups (Spearman R = -0.56, p-value<0.001). The control samples and 151 CT-scans of subjects up to age 4 years were used to create a 3D morphable model of normal hyoid shape variation (n = 197, mean age 22.1 ± 13.1 months). For the normal 3D morphable model, a high degree of allometric shape variation was observed along the first principal component. Conclusions: The 3D morphable models provide a comprehensive and quantitative description of variation in normal hyoid bone morphology, and allow detection of distinct differences between patients with isolated RS and controls.

Velopharyngeal dysfunction and speech-related characteristics in craniofacial microsomia: a retrospective analysis of 223 patients.

This study aimed to document the prevalence, severity, and risk factors of velopharyngeal dysfunction (VPD) in craniofacial microsomia (CFM) and to analyse differences in VPD-related speech characteristics between CFM patients without cleft lip and/or palate (CL/P), CFM patients with CL/P, and CL/P patients without CFM (control). A total of 223 patients with CFM were included, of whom 59 had a CL/P. Thirty-four CFM patients had VPD, including 20 with a CL/P. VPD was significantly more prevalent in CFM with CL/P than in CFM without CL/P (odds ratio (OR) 4.1, 95% confidence interval (CI) 1.9-8.7; P < 0.001). Multivariate logistic regression showed a significant association between CL/P and VPD in CFM patients (OR 7.4, 95% CI 2.1-26.3; P = 0.002). The presence of VPD was not associated with sex, the laterality or severity of CFM. Speech problems related to VPD appeared to be similar among the different groups (CFM without CL/P, CFM with CL/P, CL/P without CFM). As 15.2% of all CFM patients and 8.5% of CFM patients without CL/P had VPD, it is proposed that all patients with CFM, with or without CL/P, should be assessed by a speech and language therapist for the potential risk of VPD.

Hearing impairment and ear anomalies in craniofacial microsomia: a systematic review.

The aim of this systematic review was to review the literature on hearing impairment and ear anomalies in patients with craniofacial microsomia and to determine their prevalence. Sixty-two records including 5122 patients were included. Ear anomalies were present in 52-100% of patients. The most reported external ear malformations were microtia, pre-auricular tags, and atresia of the external auditory canal. Ossicular anomalies were the most reported middle ear malformations, whereas the most reported inner ear malformations included oval window anomalies, cochlear anomalies, and anomalies of the semicircular canals. Hearing loss in general was reported in 29-100% of patients, which comprised conductive hearing loss, mixed hearing loss, and sensorineural hearing loss. Between 21% and 51% of patients used hearing aids, and 58% underwent a surgical intervention to improve hearing. The relationship between different phenotypes of craniofacial microsomia and the type and severity of hearing loss is mostly unclear. In conclusion, the high prevalence of ear and hearing anomalies in patients with craniofacial microsomia underlines the importance of audiological screening in order to facilitate individual treatment.

Extracraniofacial anomalies in Treacher Collins syndrome: A multicentre study of 248 patients.

Treacher Collins syndrome (TCS) is a congenital malformation of the craniofacial structures derived from the first and second pharyngeal arches. The craniofacial deformities are well described in the literature. However, little is known about whether there are associated extracraniofacial anomalies. A retrospective study was conducted using data from four craniofacial units. Medical charts were reviewed for the presence and type of extracraniofacial anomalies, as well as age at diagnosis. A possible correlation between the severity of the phenotype and the presence of extracraniofacial anomalies was assessed using the Hayashi classification. A total of 248 patients with TCS were identified; 240 were confirmed to have TCS, of whom 61 (25.4%) were diagnosed with one or more extracraniofacial anomalies. Ninety-five different extracraniofacial anomalies were found; vertebral (n=32) and cardiac (n=13) anomalies were most frequently seen, followed by reproductive system (n=11), central nervous system (n=7), and limb (n=7) anomalies. No correlations between tracts were found. Extracraniofacial anomalies were more prevalent in these patients with TCS compared to the general population (25.4% vs 0.001-2%, respectively). Furthermore, a positive trend was seen between the severity of the syndrome and the presence of extracraniofacial anomalies. A full clinical examination should be performed on any new TCS patient to detect any extracraniofacial anomalies on first encounter with the craniofacial team.

Ocular and adnexal anomalies in craniofacial microsomia: Type and prevalence in a multicentre cohort study.

The aim of this multicentre retrospective cohort study was to describe and categorize the types of ocular and adnexal anomalies seen in patients with craniofacial microsomia (CFM) and to determine their prevalence. In addition, the relationship between the OMENS-Plus and Pruzansky-Kaban classification for each patient and the presence of ocular anomalies was investigated. A total of 881 patients with CFM from four different craniofacial centres were included. Data on ocular anomalies were gathered from the patient charts. Ocular anomalies were present in 33.9% of patients. Four subgroups of ocular and adnexal anomalies were identified. Type I ocular anomalies were present in 22.2%, type II in 19.0%, type III in 18.4%, and type IV in 14.5%. Several potentially preventable and treatable ocular anomalies were identified. Higher OMENS-Plus classification orbit and soft tissue scores and Pruzansky-Kaban classification mandible scores were associated with an increased risk of ocular anomalies. Based on these results and the clinical implications ocular anomalies may have, we underline the importance of targeted ophthalmological screening in CFM. Healthcare professionals should be aware of the possibility of ocular anomalies in these patients, especially during the critical period for visual development.

A novel RBF-based predictive tool for facial distraction surgery in growing children with syndromic craniosynostosis.

PURPOSE: Predicting changes in face shape from corrective surgery is challenging in growing children with syndromic craniosynostosis. A prediction tool mimicking composite bone and skin movement during facial distraction would be useful for surgical audit and planning. To model surgery, we used a radial basis function (RBF) that is smooth and continuous throughout space whilst corresponding to measured distraction at landmarks. Our aim is to showcase the pipeline for a novel landmark-based, RBF-driven simulation for facial distraction surgery in children. METHODS: An individual's dataset comprised of manually placed skin and bone landmarks on operated and unoperated regions. Surgical warps were produced for 'older' monobloc, 'older' bipartition and 'younger' bipartition groups by applying a weighted least-squares RBF fitted to the average landmarks and change vectors. A 'normalisation' warp, from fitting an RBF to craniometric landmark differences from the average, was applied to each dataset before the surgical warp. The normalisation was finally reversed to obtain the individual prediction. Predictions were compared to actual post-operative outcomes. RESULTS: The averaged change vectors for all groups showed skin and bone movements characteristic of the operations. Normalisation for shape-size removed individual asymmetry, size and proportion differences but retained typical pre-operative shape features. The surgical warps removed the average syndromic features. Reversing the normalisation reintroduced the individual's variation into the prediction. The mid-facial regions were well predicted for all groups. Forehead and brow regions were less well predicted. CONCLUSIONS: Our novel, landmark-based, weighted RBF can predict the outcome for facial distraction in younger and older children with a variety of head and face shapes. It can replicate the surgical reality of composite bone and skin movement jointly in one model. The potential applications include audit of existing patient outcomes, and predicting outcome for new patients to aid surgical planning.

Ocular and adnexal anomalies in craniofacial microsomia: a systematic review.

Ocular anomalies may occur in craniofacial microsomia (CFM). The aim of this systematic review was to review the literature on ocular anomalies and their incidence, in order to estimate the need for ophthalmological screening in CFM patients. Online databases were searched, and data on the number of patients, type and incidence of ocular anomalies, and visual acuity were extracted. Four subgroups of ocular and adnexal anomalies were identified, to provide an overview of the different anomalies. Twenty-five papers analysing 1419 patients in total were included. Ocular anomalies were documented in 6.7-100% of patients. The most reported type I ocular anomalies were eyelid coloboma, lipodermoids, and orbital dystopia. The most reported type II ocular anomalies were epibulbar dermoid, microphthalmia, and anophthalmia. Ptosis and strabismus were the most reported type III anomalies, and irregular astigmatism was the most reported type IV ocular anomaly. Visual impairment in general was reported in 8-71.4% of patients, with severe visual impairment in 11.1-71.4% and amblyopia in 16.3%. This study provides a detailed overview of ocular anomalies in CFM and their prevalence. Furthermore, we propose a new classification to organize ocular anomalies into four clinically relevant subtypes. Finally, the high prevalence of ocular anomalies and visual impairment in this study suggests that CFM patients should undergo ophthalmological screening at least once during the sensitive period.

Describing the mandible in patients with craniofacial microsomia based on principal component analysis and thin plate spline video analysis.

Craniofacial microsomia (CFM) is most often described as a unilateral malformation of derivatives of the first and second branchial arches. The mandible has been classified using several classification systems. However, all are based on two-dimensional imaging. The aim of this study was to mathematically describe the deformed mandible based on principal component analysis (PCA) in a three-dimensional way. This may aid in defining the flaws in existing surgical corrections of the mandible through the identification of the differences in shape compared with a normal mandible in a holistic view with the help of videos. Forty-three homologous landmarks were defined to describe a mandible with CFM. Computed tomography scans of 22 patients and 30 controls were marked manually. The changes in shape between the mandibles were visualized using videos. A lateral rotation with increase in posterior rotation of the condyle due to shortening of the condyle-gonial height and a longitudinal rotation with outward bending of the mandibular angle were noted on the affected side, as well as an inward bending of the angle on the unaffected side. Due to the compensatory remodelling of the mandible on the unaffected side, one could suggest that CFM is never truly unilateral.

Three-dimensional soft tissue prediction in orthognathic surgery: a clinical comparison of Dolphin, ProPlan CMF, and probabilistic finite element modelling.

Three-dimensional surgical planning is used widely in orthognathic surgery. Although numerous computer programs exist, the accuracy of soft tissue prediction remains uncertain. The purpose of this study was to compare the prediction accuracy of Dolphin, ProPlan CMF, and a probabilistic finite element method (PFEM). Seven patients (mean age 18years; five female) who had undergone Le Fort I osteotomy with preoperative and 1-year postoperative cone beam computed tomography (CBCT) were included. The three programs were used for soft tissue prediction using planned and postoperative maxillary position, and these were compared to postoperative CBCT. Accurate predictions were obtained with each program, indicated by root mean square distances: RMSDolphin=1.8±0.8mm, RMSProPlan=1.2±0.4mm, and RMSPFEM=1.3±0.4mm. Dolphin utilizes a landmark-based algorithm allowing for patient-specific bone-to-soft tissue ratios, which works well for cephalometric radiographs but has limited three-dimensional accuracy, whilst ProPlan and PFEM provide better three-dimensional predictions with continuous displacements. Patient or population-specific material properties can be defined in PFEM, while no soft tissue parameters are adjustable in ProPlan. Important clinical considerations are the topological differences between predictions due to the three algorithms, the non-negligible influence of the mismatch between planned and postoperative maxillary position, and the learning curve associated with sophisticated programs like PFEM.

Extracraniofacial anomalies in craniofacial microsomia: retrospective analysis of 991 patients.

Craniofacial microsomia (CFM) is characterized by unilateral or bilateral underdevelopment of the facial structures arising from the first and second pharyngeal arches, but extracraniofacial anomalies may also be present. This retrospective study provides an overview of the prevalence, types, and characteristics of extracraniofacial anomalies in patients with CFM. All patients diagnosed with CFM seen at four craniofacial centres were included. The patient charts were reviewed and data on patient characteristics and extracraniofacial anomalies were extracted. Of the 991 patients included, 462 (47%) had extracraniofacial anomalies. The prevalence of extracraniofacial anomalies in the various tracts was as follows: vertebral 28%, central nervous system 11%, circulatory system 21%, respiratory tract 3%, gastrointestinal tract 9%, and urogenital tract 11%. Compared to patients without extracraniofacial anomalies, those with an extracraniofacial anomaly were at higher risk of having additional extracraniofacial anomalies in other tracts. The prevalence of extracraniofacial anomalies was greater in patients with bilateral CFM, a more severe mandibular deformity, or facial nerve or soft tissue deformity. Patients with CFM should be screened for extracraniofacial anomalies by physical examination with specific attention to the circulatory, renal, and neurological tracts. Diagnostically, electrocardiography, echocardiography, spine radiography, and renal ultrasound should be performed for patients at risk of extracraniofacial anomalies.

Central nervous system anomalies in craniofacial microsomia: a systematic review.

Extracraniofacial anomalies, including central nervous system (CNS) anomalies, may occur in craniofacial microsomia (CFM). This systematic review was performed to provide an overview of the literature on the prevalence and types of CNS anomalies and developmental disorders in CFM, in order to improve the recognition and possible treatment of these anomalies. A systematic search was conducted and data on the number of patients, patient characteristics, type and prevalence of CNS anomalies or developmental delay, and correlations between CFM and CNS anomalies were extracted. Sixteen papers were included; 11 of these described developmental disorders. The most common reported anomalies were neural tube defects, corpus callosum agenesis or hypoplasia, intracranial lipoma, Arnold-Chiari malformations, hydrocephaly, ventriculomegaly, and cerebral hypoplasia. The prevalence of CNS anomalies in CFM varied from 2% to 69%. The prevalence of developmental disorders, such as intellectual disability, language or speech developmental delay, and neuropsychomotor delay, varied from 8% to 73%. This study suggests that CNS anomalies and developmental disorders are seen in a substantial proportion of patients with CFM. Further research should focus on determining which features of CFM are correlated with CNS anomalies to allow adequate screening and timely care.

Vertebral anomalies in craniofacial microsomia: a retrospective analysis of 991 patients.

Craniofacial microsomia (CFM) is characterized by an underdevelopment of the facial structures arising from the first and second branchial arches, but extracraniofacial anomalies such as vertebral anomalies may be present. This retrospective study was performed to determine the prevalence and types of vertebral anomalies and the association with other extracraniofacial anomalies in patients with CFM. The charts of all patients diagnosed with CFM seen in four craniofacial centres were reviewed for the presence of vertebral anomalies, symptoms, extracraniofacial anomalies, and the OMENS classification including the Pruzansky-Kaban type of mandibular deformity. A total of 991 patients were included and 28% of the patients had vertebral anomalies. The most common vertebral anomalies included scoliosis, block vertebrae, and hemivertebrae. Only 44% of the patients with vertebral anomalies had clinical symptoms; torticollis, back or neck pain, and limited neck movement were the most frequently seen. The prevalence of vertebral anomalies was greater in patients with bilateral CFM and in patients with a more severe mandibular deformity, and/or orbit, facial nerve, and/or soft tissue involvement. Patients with vertebral anomalies had significantly more extracraniofacial anomalies than patients without vertebral anomalies. Therefore, patients with vertebral anomalies should undergo cardiac, renal, and neurological evaluation.

Characterizing the skull base in craniofacial microsomia using principal component analysis.

The aim of this study was to compare the anatomical differences in the skull base between the affected and non-affected side in patients with craniofacial microsomia (CFM), and to compare the affected and non-affected sides with measurements from a normal population. Three-dimensional computed tomography scans of 13 patients with unilateral CFM and 19 normal patients (age range 7-12 years) were marked manually with reliable homologous landmarks. Principal component analysis (PCA), as part of a point distribution model (PDM), was used to analyse the variability within the normal and preoperative CFM patient groups. Through analysis of the differences in the principal components calculated for the two groups, a model was created to describe the differences between CFM patients and normal age-matched controls. The PDMs were also used to describe the shape changes in the skull base between the cohorts and validated this model. Using thin-plate splines as a means of interpolation, videos were created to visualize the transformation from CFM skull to normal skull, and to display the variability in shape changes within the groups themselves. In CFM cases, the skull base showed significant asymmetry. Anatomical areas around the glenoid fossa and mastoid process showed the most asymmetry and restriction of growth, suggesting a pathology involving the first and second pharyngeal arches.

Vertebral anomalies in craniofacial microsomia: a systematic review.

Craniofacial microsomia (CFM) is characterized by a heterogeneous underdevelopment of the facial structures arising from the first and second branchial arches, but extracraniofacial malformations such as vertebral anomalies also occur. This systematic review provides an overview of the literature on the types and prevalence of vertebral anomalies found in patients with CFM. A systematic search was conducted. Data on the number of patients, patient characteristics, types and prevalence of vertebral anomalies, and other associations between CFM and vertebral anomalies were extracted from the articles identified. Thirty-one articles were included. Seventeen articles described both the prevalence and types of vertebral anomalies in CFM, five articles described solely the types of vertebral anomalies in CFM, and nine articles reported solely the prevalence of vertebral anomalies in CFM. The vertebral anomalies most often reported in CFM are hemivertebrae, block vertebrae, scoliosis/kyphoscoliosis, and spina bifida. These anomalies are mostly present in the cervical and thoracic spine and ribs. The reported prevalence of vertebral anomalies in CFM varies from 8% to 79%. To diagnose vertebral anomalies early in patients with CFM, further research should focus on determining which patients with CFM are at risk of vertebral anomalies.

Obstructive sleep apnoea in craniofacial microsomia: analysis of 755 patients.

A retrospective cohort study was set up to analyse the prevalence and treatment of obstructive sleep apnoea (OSA) in relation to the severity of the deformity in patients with craniofacial microsomia (CFM). This study included a population of 755 patients with CFM from three craniofacial centres. Medical charts were reviewed for severity of the deformity, types of breathing difficulty, age at which breathing difficulty first presented, treatment for OSA, and treatment outcome. In total, 133 patients (17.6%) were diagnosed with OSA. Patients with Pruzansky IIB/III classification or bilateral craniofacial microsomia were significantly more often diagnosed with OSA than unilaterally affected patients of Pruzansky I/IIA classification. The initial treatment of OSA consisted of adenotonsillectomy, tracheotomy, or non-invasive positive pressure ventilation. Thirty-seven patients received more than one treatment (range 1-3). In this study, the prevalence of OSA in patients with CFM was higher than the prevalence in the healthy population described in the literature. Although several treatment modalities are available for the treatment of OSA in patients with CFM, treatment should be individualized and based on clinical symptoms, the severity of the deformity, and comorbidities.

Feeding difficulties in craniofacial microsomia: a systematic review.

Patients with craniofacial microsomia are at higher risk of developing obstructive sleep apnoea (OSA), as described in the previous article entitled "Obstructive sleep apnoea in craniofacial microsomia: a systematic review". These patients are also more likely to develop feeding difficulties. The present systematic review provides an overview of the literature on the prevalence, treatment, and follow-up of feeding difficulties in children with craniofacial microsomia (CFM). A search was performed in PubMed, Embase, Cochrane Library, and Web of Science for articles on CFM and feeding difficulties. The following data were extracted from the articles: number of patients, patient characteristics, presence of feeding difficulties, and the treatment and outcomes of feeding difficulties. Eight articles on CFM and feeding difficulties were included, two of which reported the prevalence of feeding difficulties (range 42-83%). Treatment mostly consisted of tube feeding. No information regarding follow-up was found in these articles. According to the literature, feeding difficulties are related to CFM. However, as there have been no prospective studies and few studies have presented objective measurements, no definitive conclusions can be drawn. Prospective studies are needed to determine the prevalence of feeding difficulties in patients with CFM.

Obstructive sleep apnoea in craniofacial microsomia: a systematic review.

Children with craniofacial microsomia (CFM) are at risk of obstructive sleep apnoea (OSA). This systematic review provides an overview of the literature on the prevalence of OSA in children with CFM. A search was performed in PubMed, Embase, Cochrane Library, and Web of Science for articles on CFM and OSA. The following data were extracted from the articles: number of patients, patient characteristics, presence of OSA, polysomnography outcomes, and the treatments and outcomes of OSA. We included 16 articles on CFM and OSA, four of which reported the prevalence of OSA (range 7-67%). Surgical treatment was more often described in these patients than conservative treatment. According to the literature, OSA is related to CFM. However, as there have been no prospective studies and few studies have presented objective measurements, no definitive conclusions can be drawn. Prospective studies are needed to determine the prevalence of OSA in patients with CFM.

Monitoring of intestinal transplant rejection.

Our results show that maltase, sucrase, and lactase activity are present at a normal level in nonrejecting small bowel transplants after an initial postoperative decline. This confirms that the disaccharide absorbing capacity of these grafts is intact. In allogeneic bowel, however, the levels of maltase and sucrase decline as histologic rejection occurs. These results suggest that serial maltase, sucrase, and possibly lactase levels in allogeneic intestinal transplants may serve as a useful adjunct in the monitoring of small bowel transplant rejection.

Small-bowel transplantation permits survival in rats with lethal short-gut syndrome.

The functional integrity of transplanted bowel would most convincingly be demonstrated if transplantation after an otherwise lethal intestinal resection permitted survival and growth. In this experiment, we proposed to define the extent of bowel resection necessary for lethality and to show that transplantation allows salvage of these animals. Adult Brown-Norway rats (250 g) underwent extensive small-bowel resection (SBR) (ligament of Treitz to ileocecal valve) (n = 5), cecectomy only (CEC) (n = 3), SBR plus CEC (n = 6), or SBR plus CEC and syngeneic transplantation of 25 cm of jejunum (n = 6). All animals with SBR or CEC alone survived and grew; all animals with SBR plus CEC died within 2 weeks (mean, 6.4 days); and 6 of 6 animals with SBR plus CEC and transplant survived and grew. The difference in survival between the lethally resected rats and those with an intestinal transplant was highly significant (P less than 0.01). Dietary intake was similar in all groups. We conclude that in the rat, extensive small-bowel resection alone is not sufficient to be lethal; most of the small bowel and the cecum must be resected to obtain a lethal model. We have also shown that transplantation of small bowel into rats with an otherwise lethal extent of bowel resection will allow the animals to survive and grow. These results suggest the need for caution in correlating survival after intestinal transplantation in the rat with transplant function, since the preservation of too much native gut might permit survival even if the transplant has no nutritional function.

Alteration in gastrointestinal peptide tissue levels in rejecting small bowel transplants.

Gastrointestinal (GI) peptide tissue levels were measured following intestinal transplantation in rats and evaluated as a possible early marker of transplant rejection. Vascularized syngeneic and allogeneic jejunal transplants were performed in rats without immunosuppressive therapy. Serial tissue samples of transplanted intestine were obtained from each group of animals. Baseline levels of peptides were determined in nontransplanted jejunum of the same animals. Results were correlated with histology at all experimental time points. Tissue levels of gut peptides (somatostatin, vasoactive intestinal peptide and substance P) were determined by two methods--immunoperoxidase staining and radioimmunoassay. Normal levels of gut peptides in syngeneic bowel were maintained up to 1 year after transplantation. Allogeneic bowel showed a progressive decline in gut peptide concentrations simultaneously with (or preceding) histologic evidence of rejection. The monitoring of GI peptide tissue levels may prove to be a useful method of detecting small bowel transplant rejection.