Prenatal diagnosis of Treacher Collins syndrome: A case report and literature review

Treacher Collins syndrome (TCS) should be suspected if the triad of micrognathia, glossoptosis, and posterior cleft palate, and deformed external ears are observed during prenatal ultrasonography, excepting Pierre Robin sequence. Visualization of the fetal zygomatic bone and down-slanting palpebral fissures are conducive to differentiation. Molecular genetics testing can establish a definite diagnosis. A 28-year-old pregnant Chinese woman was referred for systematic ultrasound examination at 24 weeks. Two-dimensional and three-dimensional ultrasound showed polyhydramnios, micrognathia, absence of nasal bone, microtia, secondary cleft palate, mandibular hypoplasia, glossoptosis, and normal limbs and vertebrae. Pierre Robin sequence was misdiagnosed with the triad of micrognathia, glossoptosis, and posterior cleft palate. Final diagnosis of TCS was confirmed by whole-exome sequencing. Visualization of the fetal zygomatic bone and down-slanting palpebral fissures can facilitate a differential diagnosis between Pierre Robin sequence and TCS, with the triad of micrognathia, glossoptosis, and posterior cleft palate.

Otodental syndrome: Case report and differential diagnosis with Treacher Collins syndrome

BACKGROUND

Otodental syndrome and Treacher Collins syndrome are rare diseases that have similar clinical features, which can complicate the diagnostic process. These syndromes cause skeletal and dental abnormalities, the differential diagnosis can be based on clinical signs but only the genetic analysis can confirm it. The aim of this case report is to describe and compare clinical signs of these syndromes.

CASE REPORT

A 7-year-old patient came to our department: he presented abnormal tooth shapes and sizes, delayed teeth replacement and micrognathia. After extra- and intra-oral examination and radiographic exams, a clinical diagnosis of otodental syndrome was made, and a genetic testing was requested to confirm the diagnosis.

CONCLUSION

Dental management of patients with otodental syndrome is challenging due to agenesis, teeth malformation, lack of space for permanent dentition. Proper treatment decision is crucial to obtain the best result for the patient.

Treacher Collins Syndrome: A Case Report

Treacher collins syndrome (TCS) or Franceschetti syndrome is an autosomal dominant inherited disorder with variable expressivity. It affects mainly craniofacial structure that derives from 1st and 2nd branchial arches approximately between the 20th day and 12th week of intrauterine life. This syndrome has different clinical types. Most common features are antimongoloid slanting of the palpebral fissures, hypoplasia of zygoma, maxilla & mandible with various eye and ear abnormalities. Here we present a case of an 11 days old female neonate, who was ill looking, dyspnoeic having significant facial profile, multiple congenital anomalies and dolicocephaly; admitted in the department of Neonatology, Mymensingh Medical College Hospital (MMCH), Mymensingh, Bangladesh on 7th August 2020. After taking all the diagnostic assistance of the multidisciplinary approach mainly on the basis of clinical features and radiology we diagnosed the case as TCS. We managed the patient by maintaining temperature, giving nutritional support and injectable antibiotic, took consultation from Otolaryngology department then we discharged the baby with proper counseling, advised regarding further follow up and to consult with paediatric surgeon and cardiologist.

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.

Imaging of the Fetal Zygomatic Bone: A Key Role in Prenatal Diagnosis of First Branchial Arch Syndrome

OBJECTIVES

First arch syndromes are congenital defects caused by failure of neural crest cells to migrate into the first branchial arch. First arch syndrome is classified into 2 main clinical manifestations: Treacher Collins syndrome, characterized by bilateral underdevelopment of the zygomatic bones; and Pierre Robin sequence. The aim of this study was to describe the feasibility of visualization of the fetal zygomatic bone and assess its application in cases referred for features suggestive of first arch syndrome.

METHODS

A prospective cohort study was conducted. The feasibility of visualization of the zygomatic bone was performed in 50 sequential fetuses with a normal anatomic scan between 12 and 24 weeks' gestation using 3-dimensional sonography. Following this, cases referred for targeted scans for suspected first branchial arch syndrome were assessed for the presence or absence of the zygomatic bones.

RESULTS

Visualization of the fetal zygomatic bone was feasible in all low-risk cases. Cases referred for targeted scans included 11 isolated cases of micrognathia or retrognathia, 3 cases of microtia, and 3 cases of auricular or facial vestiges. Within this group, the zygomatic bones were visualized in all but 2 cases. No associated extrafacial malformations were detected; therefore, this phenotype was consistent with Treacher Collins syndrome.

CONCLUSIONS

Prenatal imaging of the zygomatic bones offers a clinically based sonographic approach to cases referred for features suggestive of first arch syndrome and enables differentiation between the 2 main clinical manifestations: Treacher Collins syndrome and Pierre Robin sequence.

Mutations in the Neuroblastoma Amplified Sequence gene in a family affected by Acrofrontofacionasal Dysostosis type 1

Acrofrontofacionasal Dysostosis type 1 (AFFND1) is an extremely rare, autosomal recessive syndrome, comprising facial and skeletal abnormalities, short stature and intellectual disability. We analyzed an Indian family with two affected siblings by exome sequencing and identified a novel homozygous truncating mutation in the Neuroblastoma-Amplified Sequence (NBAS) gene in the patients' genome. Mutations in the NBAS gene have recently been associated with different phenotypes mainly involving skeletal formation, liver and cognitive development. The NBAS protein has been implicated in two key cellular processes, namely the non-sense mediated decay and the Golgi-to-Endoplasmic Reticulum retrograde traffic. Both functions were impaired in HEK293T cells overexpressing the truncated NBAS protein, as assessed by Real-Time PCR, Western blot analysis, co-immunoprecipitation, and immunofluorescence analysis. We examined the expression of NBAS protein in mouse embryos at various developmental stages by immunohistochemistry, and detected expression in developing chondrogenic and osteogenic structures of the skeleton as well as in the cortex, hippocampus and cerebellum, which is compatible with a role in bone and brain development. Functional genetics in the zebrafish model showed that depletion of endogenous z-nbas in fish embryos results in defective morphogenesis of chondrogenic cranial skeletal elements. Overall, our data point to a conserved function of NBAS in skeletal morphogenesis during development, support the hypothesis of a causative role of the mutated NBAS gene in the pathogenesis of AFFND1 and extend the spectrum of phenotypes associated with defects in this gene.

Mandibulofacial dysostosis with microcephaly: A case presenting with seizures

We report a case of mandibulofacial dysostosis with microcephaly presenting with seizures. The proband, a 6-year-old Korean boy, had microcephaly, malar and mandibular hypoplasia, and deafness. He showed developmental delay and had suffered recurrent seizures beginning at 21months of age. Electroencephalography revealed occasional spike discharges from the right frontal area. Head magnetic resonance imaging revealed dilatation of the lateral ventricles and a small frontal lobe volume. Whole exome sequencing revealed a de novo frame shift mutation, c.2698_2701 del, of EFTUD2. The epileptic focus was consistent with the reduced frontal lobe volume on head magnetic resonance imaging. Seizures are thus a main feature of mandibulofacial dysostosis with microcephaly, which results from an embryonic development defect due to the EFTUD2 mutation.

Altered mRNA Splicing, Chondrocyte Gene Expression and Abnormal Skeletal Development due to SF3B4 Mutations in Rodriguez Acrofacial Dysostosis

The acrofacial dysostoses (AFD) are a genetically heterogeneous group of inherited disorders with craniofacial and limb abnormalities. Rodriguez syndrome is a severe, usually perinatal lethal AFD, characterized by severe retrognathia, oligodactyly and lower limb abnormalities. Rodriguez syndrome has been proposed to be a severe form of Nager syndrome, a non-lethal AFD that results from mutations in SF3B4, a component of the U2 small nuclear ribonucleoprotein particle (U2 snRNP). Furthermore, a case with a phenotype intermediate between Rodriguez and Nager syndromes has been shown to have an SF3B4 mutation. We identified heterozygosity for SF3B4 mutations in Rodriguez syndrome, confirming that the phenotype is a dominant disorder that is allelic with Nager syndrome. The mutations led to reduced SF3B4 synthesis and defects in mRNA splicing, primarily exon skipping. The mutations also led to reduced expression in growth plate chondrocytes of target genes, including the DLX5, DLX6, SOX9, and SOX6 transcription factor genes, which are known to be important for skeletal development. These data provide mechanistic insight toward understanding how SF3B4 mutations lead to the skeletal abnormalities observed in the acrofacial dysostoses.

The acrofacial dysostoses (AFD) are inherited disorders with abnormalities of the facial and limb bones. Rodriguez syndrome is a severe type of AFD that is usually lethal in the immediate perinatal period. Rodriguez syndrome has been proposed to be a severe form of Nager syndrome, a non-lethal AFD that results from mutations in SF3B4, a component of mRNA splicing machinery needed for proper maturation of primary transcripts. Furthermore, a case with a phenotype intermediate between Rodriguez and Nager syndromes has been shown to have an SF3B4 mutation. We found that mutations in SF3B4 produce Rodriguez syndrome, further demonstrating that it is allelic with Nager syndrome. The consequences of the mutations include abnormal splicing and reduced expression in growth plate chondrocytes of genes that are important for proper development of the skeleton, providing mechanistic insight toward understanding how SF3B4 mutations lead to the skeletal abnormalities observed in the acrofacial dysostoses.

Acrofacial dysostosis syndromes: A relevant prenatal dilemma. A case report and brief literature review

The acrofacial dysostosis (AFD) syndromes are an heterogeneous group of disorders with undefined classification and inheritance. We report the sonographic and clinical features of an AFD fetus with predominantly pre-axial forms. We made a prenatal diagnosis of Nager syndrome but postnatal examination showed post-axial defects previously undetectable by ultrasound.

The Use of Three-Dimensional Computed Tomography Images for Anticipated Difficult Intubation Airway Evaluation of a Patient with Treacher Collins Syndrome

A 13-year-old girl with Treacher Collins syndrome who had a history of difficult intubation was scheduled for plastic surgery. We took three-dimensional computed tomography images to better evaluate the anatomical features of the upper airway. The patient's anesthetic airway management was influenced by the findings of the images.

Dental and facial bone abnormalities in pyknodysostosis: CT findings

Pyknodysostosis is an autosomal-recessive disorder of osteoclast dysfunction causing osteosclerosis, with associated maxillofacial anomalies. Multidetector CT with multiplanar and 3D reconstruction illustrated the pathologic findings in this case. Abnormalities included multiple retained deciduous teeth, unerupted teeth with associated follicles, an irregularly expanded alveolus and body of the mandible, and an obtuse mandibular angle. Volume-rendered imaging better delineated the irregular dentition, with crowding and retention of deciduous teeth.

Craniofacial Structures and Dental Development in Three Patients With Nager Syndrome

In Finland, 3 patients have been diagnosed with Nager syndrome (NS) during the last 17 years. Thus the incidence for NS in Finland is 3:1,000,000. The craniofacial structures and dental development of these patients were studied clinically and radiographically at the age of 3-4 years, and compared to age-matched controls and to the norms of the Finnish population. The striking structural finding was a severely short, retrognathic and posteriorly rotated mandible. Especially the ramus was deficient; its height was, on average, less than one-third of that of the control group. All children were tracheostomized neonatally. At the age of 3-4, the lower pharyngeal airway was still severely obstructed or completely closed. Nasopharyngeal airway was wide and the soft palate was missing in all patients. All patients had a complete deciduous dentition, but agenesis of permanent teeth (ranging from 2-10 missing teeth) was observed in each patient. Accelerated dental development was found in two subjects. Condylar ankylosis or severely limited mouth opening were observed. The present findings give new information and quantify earlier observations of craniofacial structures and dental development in NS. Analysis of facial structures suggests that if surgical intervention is needed to enable better breathing, the goal of the structural correction should be aimed at the most deficient structure, namely the ramus height. As a result of severe dentofacial deviation, a treatment process through the growth requires multidisciplinary teamwork of surgeons, pediatrists, orthodontists and prosthodontists.

[Diagnostic value of multi-slice spiral CT three dimensional reconstruction in maxillofacial diseases]

OBJECTIVE

To evaluate the diagnostic value of multi-slice spiral CT (MSCT) three dimensional (3D) reconstruction for maxillofacial diseases.

METHODS

Sixty patients with maxillofacial diseases underwent the scanning of MSCT with 3D reconstruction. Among them, 34 patients with maxillofacial fracture, 10 patients with maxillofacial tumors and tumor-like diseases, and 16 patients with congenital deformities. The MSCT scanned with slice thickness of 2 mm. The methods of 3D reconstruction included multi-planar reconstruction (MPR), shaded surface display (SSD), and volume rendering (VR). The results were compared with what was observed during operations.

RESULTS

Totally 36 cases of maxillofacial fracture were shown by 2D or 3D imaging and were validated by the observations during operation. The MSCT with 3D reconstruction imaging was significantly superior to 2D axial imaging in maxillofacial fracture. Three dimensional imaging could clearly show the spacial anatomy of facial, fragment displacement, and tracing fracture lines. However, 2D imaging had better effectiveness than 3D imaging in observing deep structure and fine fracture. In maxillofacial tumors and tumor-like diseases, 3D imaging was significantly superior to 2D axial imaging in showing the tumor shape and spacial relationships between tumors and surrounding structures. Two dimensional imaging and MPR imaging were excellent to reveal internal structure and pathological changes of tumors. 2D imaging and MPR imaging also achieved better results in showing tumors extended to soft tissues. In maxillofacial congenital deformities, 3D imaging were superior than 2D imaging.

CONCLUSION

3D imaging has an important value in the diagnosis and clinical assessment of maxillofacial fracture, tumor-like diseases, and congenital deformities.

[Musculoskeletal connections. Study of two cases of oto-mandibular dysplasia]

The current genetic data stress the importance of musculo-skeletal connections in the development of a coherent system connecting the tendons and aponeurosis muscles with the osseous parts. The observations in tomodensitometry of musculo-skeletal connections in otomandibular dysostosis make it possible qualitatively to observe the development of the muscles and their functions.

Facial canal anatomy in patients with mandibulofacial dysostosis: comparison with respect to the severities of microtia and middle ear deformity

OBJECTIVE

To study the difference in the facial canal anatomy in terms of the severity of microtia and deformity of the middle ear in patients with mandibulofacial dysostosis using high-resolution computed tomography.

STUDY DESIGN

Retrospective analyses.

SETTING

The study was carried out at the Department of Otorhinolaryngology, University of Tokyo, Tokyo, Japan.

PATIENTS

Thirty-six ears of 18 patients with mandibulofacial dysostosis were examined by high-resolution computed tomography. These ears were graded based on the Marx classification and Jahrsdoerfer scoring systems.

MAIN OUTCOME MEASURES

The high-resolution computed tomography findings and age distribution of each group were compared with those of other groups by multiple comparison using Tukey's honestly significant difference test.

RESULTS

The course of the facial nerve was not significantly different in terms of the severity of microtia and deformity of the middle ear. The bony cochlea in the patients with mandibulofacial dysostosis was displaced by a mean value of 2 mm more anteriorly and a mean value of 0.7 mm shallower than that in the cases with normal auricles.

CONCLUSION

The facial nerve of patients with mandibulofacial dysostosis is displaced more anterolaterally than that of the cases with normal auricles; however, the auricle anomaly is not severe.

Mandibular osteomyelitis and fracture successfully treated with vascularised iliac bone graft in a patient with pycnodysostosis

Pycnodysostosis is a rare sclerosing bone disorder. Complications such as osteomyelitis and fracture of the jaws are not uncommon and difficult to treat. Treatment by reconstruction with a reconstruction plate and an iliac bone graft fails in most cases. We report a case of pycnodysostosis with osteomyelitis and fracture of the mandible that was successfully treated with vascularised iliac bone graft. We believe that this procedure is the best method for the treatment of this condition.

New hope for Treacher-Collins syndrome: a surgical case report

The objective of this case report is to discuss the possibility of developing a surgical treatment paradigm for patients with some of the noted characteristics of Treacher-Collins syndrome, mainly mandibular ankylosis and/or retrognathia (mandibular retrusion), in a way that would provide lasting, predictable results and minimize the frequently seen mandibular ankylosis. Through various medical imaging techniques, mainly computed tomography (CT) scan, the radiology imaging technologist produces accurate CT scan images of the particular patient's osseous cranial structures. These images can then be used by the stereolithography (SLA) technician to construct accurate SLA models. The SLA models can then be used by the surgical and implant design team to not only prescribe the surgical correction necessary, but also design and construct the actual temporomandibular joint (TMJ) and mandibular implants, as well as perform mock surgery, which will be needed to restore function and esthetics for the patient. The early results from this alloplastic reconstructive surgery have provided the anticipated results of relieving the ankylosis, improving jaw function and frequently dental occlusion, as well as improving the esthetics. Without this breakthrough surgical development, many of these Treacher-Collins syndrome patients will not be able to enjoy normal breathing, mastication, jaw function, esthetics, oral and dental health, and the emotional relief these corrections allow. Many patients who suffer the disfiguring and functionally damaging affects of Treacher-Collins syndrome never receive the surgical correction necessary. Many have had autogenous reconstruction of missing mandibular and TMJ structures, only to sometimes relapse into a more disfiguring and lasting condition. By simply placing a Christensen Fossa-Eminence Prosthesis(r) (TMJ Implants, Inc., Golden CO, USA) between the cranial base and any bone graft, one is more likely to achieve satisfactory TMJ mobility. If a condylar or mandibular reconstruction is necessary, the Christensen Total TMJ Prostheses(r) (TMJ Implants, Inc., Golden CO, USA) are available and provide excellent results.

Neonatal Distraction Surgery for Micrognathia Reduces Obstructive Apnea and the Need for Tracheotomy

The objective of the study was to assess the effectiveness of neonatal mandibular distraction in treatment of obstructive sleep apnea in the perinatal period in preventing a tracheotomy. This was a prospective study of 17 infants at two centers with severe micrognathia who demonstrated obstructive sleep apnea refractory to conservative therapy. Age at surgery varied from 5 to 120 days. Distraction was performed at a rate of 2 mm/d. After distraction, callus consolidation was allowed for 4 to 6 weeks, and the device was then removed. Each child underwent a three-dimensional computed tomography scan before surgery and approximately 3 months after surgery. Of the 17 patients, 14 successfully underwent extubation and demonstrated significant improvement in the obstructive sleep apnea. Postoperative horizontal ramus length increased from 23.3 to 34.8 mm after surgery. Mean maxillary mandibular discrepancy was 8.28 mm before surgery and 2.2 mm after surgery. Ten infants who underwent pre- and postoperative polygraphic studies showed improvement in obstructive apnea. Three patients had postoperative polysomnographic studies only; the results were also within the normal range. The mean follow-up interval was 16.5 months (range: 8-48 months). Neonatal distraction is an effective method for treatment of micrognathia with obstructive sleep apnea in the perinatal period in preventing a tracheotomy.

Aplasia of zygomatic arch and dislocation of temporomandibular joint capsule in Treacher-Collins syndrome: three-dimensional reconstruction of computed tomographic scans

Seven patients with Treacher-Collins syndrome were studied. All of patients were children or teenagers. Helical CT scanner (Toshiba) was used to reconstruct zygomatic arch and temporomandibular joint capsule on lateral aspect of temporal bone in five patients of microtia and atresia of both ears and two patients of narrow ear canals of both ears without microtia.Three-dimensional reconstructions of computed tomography on lateral aspect of temporal bone demonstrated various congenital abnormality including aplasia of zygomatic arch in seven patients and dislocation of temporomandibular joint capsule in seven patients.

Ultrasonographic prenatal diagnosis of Treacher Collins syndrome: a case report

A case of Treacher Collins syndrome (TCS) diagnosed prenatally using ultrasonography is reported. The pregnant woman was gravida 2, para 0. Her husband had stigmata of the syndrome. Ultrasonography revealed polyhydramnios, abnormal fetal ears and marked micrognathia. Abortion occurred spontaneously at 26 weeks of gestation. The abortus bore clinical features of the syndrome.

Prenatal ultrasound diagnosis of Nager syndrome

Nager syndrome, or acrofacial dysostosis, is a rare malformation complex characterized by facial anomalies (external ear abnormalities and micrognathia) and limb defects (radial hypoplasia and absence of the thumb and/or other digits). Since its first description in 1948, more than 80 cases have been reported in the pediatric literature. However, there is only one previous report on the prenatal recognition of the syndrome, which was at 30 weeks of gestation. We report here a further case of Nager syndrome, prospectively diagnosed at 23 weeks of gestation.

External auditory canal duplication anomalies associated with congenital aural atresia

Maldevelopment of the first branchial cleft can produce a broad spectrum of anomalies in its derivative structure, the external auditory canal (EAC). Failure of the cleft to develop normally can result in either the absence of a normally patent EAC (atresia, or stenosis) or a duplication anomaly (cyst, sinus, or fistula). Despite their common origins, the coexistence of these anatomical abnormalities is quite unusual. We present four patients with both aural atresia and duplication anomalies of the EAC. Three patients had non-syndromic unilateral aural atresia and presented with periauricular lesions originating from the first branchial cleft. The other patient had a variant of Treacher Collins syndrome and presented with draining infra-auricular fistulae. The classification and management of first branchial cleft anomalies is reviewed in light of these cases. An understanding of the embryogenesis of the external ear is necessary to successfully recognize and treat this spectrum of deformities. A classification system is presented that encompasses the full spectrum of first cleft anomalies.

Facial canal anatomy in patients with microtia: evaluation of the temporal bones with thin-section CT

PURPOSE

To ascertain the location of the facial nerve in patients with microtia by using thin-section computed tomography (CT).

MATERIALS AND METHODS

Thin-section CT was performed in 66 ears of patients with microtia (unilateral, n = 12; bilateral, n = 34) and mandibulofacial dysostosis (MFD, n = 20). Findings were compared with those in 22 ears with normal auricles (control group) by using the Dunnett two-sided t test.

RESULTS

The facial nerve at the mastoid portion in patients with MFD was 2 mm more lateral and 3 mm more anterior than that in control subjects (P <.01). The same portion in patients with microtia was 3 mm more anterior than that in the control subjects (P <.01). The distance between the facial nerve and the most lateral point of the temporal bone in patients with MFD was 10 mm shorter and that in patients with bilateral microtia was 3 mm shorter than that in the control subjects (P <.01).

CONCLUSION

The facial nerve in patients with microtia was not more lateral from the Bill bar (vertical crest) than that in control subjects. The facial nerve in patients with MFD was different from that in patients with microtia who had no other head anomalies.

Prenatal diagnosis and confirmation of the acrofacial dysostosis syndrome type Rodriguez

The group of acrofacial dysostosis (AFD) syndromes is very heterogeneous and contains many different entities. In 1990, Rodriguez et al. [1990: Am J Med Genet 35:484-489] described a new type of AFD characterized by severe mandibular hypoplasia, phocomelia and oligodactyly of the upper limbs, absence of fibulae, microtia, cleft palate, internal organ anomalies including arrhinencephaly and abnormal lung lobulation, and early lethality. We describe another case of AFD type Rodriguez, identified by prenatal ultrasonography at 25 weeks of gestation.

Effect of distraction osteogenesis of the mandible on upper airway volume and resistance in children with micrognathia

Children with craniofacial anomalies often have compromise of the upper airway, a condition with potential for morbidity and mortality. In children with microretrognathia, the diminutive size and retruded position of the mandible reduces the size of the oropharynx, thereby predisposing to glossoptosis and airway obstruction. Although several authors have reported successful use of mandibular distraction osteogenesis to alleviate this type of upper airway obstruction, the physiologic relationship between changes in mandibular shape, size, and position and upper airway dynamics remains undefined. The purpose of this study was to develop methodologies to quantitatively evaluate upper airway dynamics in children with micrognathia both before and after mandibular distraction osteogenesis. The patient population consisted of four children with micrognathia who had successfully undergone upper airway stabilization by bilateral mandibular distraction osteogenesis. The data used were digitally archived computed tomographic scan data from high-resolution, thin-slice head computed tomographic scans obtained before and after mandibular distraction. Upper airway evaluation was performed in two ways: static and dynamic. Static analysis consisted of computer quantification of predistraction and postdistraction mandibular and upper airway volumes using Analyze imaging software. Dynamic analysis consisted of fabrication of rigid stereolithographic hollow cast models of the upper airway produced from computed tomographic scan data. Models were used for characterization of upper airway resistance and flow patterns as related to respiration. After distraction osteogenesis, mandibular total volume increased 32, 32, 18, and 25 percent (mean, 27 percent) and upper airway volume increased by 20, 31, 23, and 71 percent (mean, 37 percent). A significant decrease in flow resistance, both inspiratory and expiratory, was observed in the patient with the greatest upper airway volume increase (71 percent) after distraction. After distraction, the inspiratory resistance was diminished by 51 percent and the expiratory resistance diminished by 85 percent. However, the three patients with more modest upper airway volume increases of 20 to 31 percent demonstrated no statistically significant change in flow resistance after distraction. Results of this study support the conclusion that distraction osteogenesis of the micrognathic mandible increases the volume of the upper airway, roughly paralleling the increase in mandibular volume. In the biomechanical airway model studied, upper airway volume expansion has been shown to be able to decrease the flow resistance over the length of the airway, presumably secondary to an increase in the average cross-sectional area. The artificial rigidity of the stereolithographic "airway" compared with the elasticity of the human upper airway may account for the insensitivity of this model to smaller but clinically significant airway changes.

Syndromic ear anomalies and renal ultrasounds

OBJECTIVE

Although many pediatricians pursue renal ultrasonography when patients are noted to have external ear malformations, there is much confusion over which specific ear malformations do and do not require imaging. The objective of this study was to delineate characteristics of a child with external ear malformations that suggest a greater risk of renal anomalies. We highlight several multiple congenital anomaly (MCA) syndromes that should be considered in a patient who has both ear and renal anomalies.

METHODS

Charts of patients who had ear anomalies and were seen for clinical genetics evaluations between 1981 and 2000 at Cedars-Sinai Medical Center in Los Angeles and Dartmouth-Hitchcock Medical Center in New Hampshire were reviewed retrospectively. Only patients who underwent renal ultrasound were included in the chart review. The literature was reviewed for the epidemiology of renal anomalies in the general population and in MCA syndromes with external ear anomalies. We defined a child as having an external ear anomaly when he or she had any of the following: preauricular pits and tags; microtia; anotia; or cup, lop, and other forms of dysplastic ears. A child was defined as having a renal anomaly if an ultrasound revealed any of the following: unilateral or bilateral renal agenesis; hypoplasia; crossed ectopia; horseshoe, pelvic, cystic kidney; hydronephrosis; duplicated ureters; megaureter; or vesicoureteric reflux.

RESULTS

Because clinical genetics assessments were made by the same clinician at both sites (J.M.G.), data were combined. A total of 42 patients with ear anomalies received renal ultrasound; 12 (29%) of them displayed renal anomalies. Of the 12 patients with renal anomalies, 11 (92%) also received a diagnosis of MCA syndrome. Eleven of 33 patients (33%) with MCA syndromes had renal anomalies, whereas 1 of 9 patients (11%) with isolated ear anomalies had renal anomalies. Specific disorders seen were CHARGE association, Townes-Brocks syndrome, branchio-oto-renal syndrome, Nager syndrome, and diabetic embryopathy.

CONCLUSIONS

We conclude that ear malformations are associated with an increased frequency of clinically significant structural renal anomalies compared with the general population. This is due to the observation that auricular malformations often are associated with specific MCA syndromes that have high incidences of renal anomalies. These include CHARGE association, Townes-Brocks syndrome, branchio-oto-renal syndrome, Nager syndrome, Miller syndrome, and diabetic embryopathy. Patients with auricular anomalies should be assessed carefully for accompanying dysmorphic features, including facial asymmetry; colobomas of the lid, iris, and retina; choanal atresia; jaw hypoplasia; branchial cysts or sinuses; cardiac murmurs; distal limb anomalies; and imperforate or anteriorly placed anus. If any of these features are present, then a renal ultrasound is useful not only in discovering renal anomalies but also in the diagnosis and management of MCA syndromes themselves. A renal ultrasound should be performed in patients with isolated preauricular pits, cup ears, or any other ear anomaly accompanied by 1 or more of the following: other malformations or dysmorphic features, a family history of deafness, auricular and/or renal malformations, or a maternal history of gestational diabetes. In the absence of these findings, renal ultrasonography is not indicated.

Imaging the neonatal mandible for accurate distraction osteogenesis

The position of mandibular teeth is difficult to document in the neonatal patient. Panorex images are difficult to obtain in an uncooperative pediatric patient. The new technique presented by the authors uses computed tomographic data to create a curved, reformatted image of the mandible, and generates an image similar to a panorex image. This curved, reformatted mandibular image provides accurate visualization of the mandible and mandibular teeth. This technique allows for precise pin placement and osteotomy in distraction osteogenesis.

Three-dimensional spiral CT of craniofacial malformations in children

OBJECTIVE

To assess the value of three-dimensional CT (3D CT) in the diagnosis and management of suspected paediatric craniofacial malformations.

MATERIALS AND METHODS

Twenty-eight children (12 girls, 16 boys) with a mean age of 4 years, suffering from craniofacial or cervical malformations, underwent craniofacial spiral CT. 3D reformatting was performed using an independent work-station.

RESULTS

3D CT allowed the preoperative evaluation of 16 patients with craniosynostosis and the post-surgical management of 2 patients. 3D CT clearly depicted malformations of the skull base involving the petrous bone in seven patients (four cases of Goldenhar-Gorlin syndrome, one case of Treacher-Collins syndrome and two cases of Crouzon's disease). Four patients with craniofacial clefts were also evaluated. Radiological findings were confirmed by the clinical and intraoperative findings in all patients that underwent surgical treatment. Movement artefacts and "Lego effect" related to abrupt change of cranial vault border were encountered and are discussed.

CONCLUSIONS

3D CT of the skull can safely and reliably identify paediatric craniofacial malformations involving bone, and it should be used as morphological mapping to help the surgeon in planning surgical treatment.

Mandibulofacial dysostosis: CT evaluation of the temporal bones for surgical risk assessment in patients of bilateral aural atresia

We present the results of detailed CT investigation of nine patients with mandibulofacial dysostosis (MFD). We also graded the severity of microtia according to Marx's classification system. The results revealed a positive correlation between the severity of microtia and the severity of deformity of the external auditory canal, and attic formation. In 13 ears, the stapes was not adequately visualized to allow any comment on its form. The angle of the first genu of the facial nerve ranged from 55.0 to 123.6 degrees (mean +/-S.D.; 99.5 +/-18.5 degrees ), indicating that this angle is more obtuse in MFD patients than in normal subjects. The eustachian tube and tympanic sinus were present in all the ears examined. None of the patients had mastoid pneumatization. In four ears, the lateral semicircular canal was dysplastic. Eleven ears of six patients scored less than 5 in the grading system developed by Jahrsdoerfer for assessment of the suitability for atresia surgery. These findings indicate that most patients with mandibulofacial dysostosis are poor surgical candidates.

Mandibulofacial dysostosis--variability in facial morphology and growth: a long-term profile roentgenographic and roentgen stereometric analysis of three patients

OBJECTIVE

To monitor and compare facial morphology and growth in three individuals with variable expression of mandibulofacial dysostosis (MFD) in terms of changes in the skeletal profile and in terms of growth in the circummaxillary sutures and temporomandibular joints (TMJs).

DESIGN

Retrospective conventional profile roentgenography (mean age 9 to 18 years) and prospective roentgen stereometric analysis (RSA) (mean age 7 to 17 years).

SETTING

Center for Craniofacial Anomalies and Department of Plastic and Reconstructive Surgery, Malmö University Hospital, Sweden.

PATIENTS

The first three MFD patients seen by one of the authors (B.R.).

INTERVENTIONS

Surgery was performed at the Department of Plastic and Reconstructive Surgery. Implants were inserted at surgery under general anesthesia. Roentgen examinations were performed in connection with continued clinical evaluations and treatment.

MAIN OUTCOME MEASURES

All profile roentgenograms were traced and measured by one of the authors (K.-V.S.) using a conventional point-based analysis.

RESULTS

The more afflicted patient showed a greater total difference in profile morphology and growth from the norm and more pronounced effects of articular growth restriction. Little change in the skeletal profile was associated with considerable displacement of the jaws.

CONCLUSIONS

The variability in MFD expression and surgical procedures in our patients is reflected less in the skeletal profile morphology and growth and more in the displacement of the jaws.

Multi-facial anomalies in mandibulofacial dysostosis. A report of three cases

Mandibulofacial dysostosis is readily recognized on the basis of a characteristic facial appearance caused by hard and soft tissue abnormalities of the face, including malformations of the ear. Generally, the abnormality is symmetrical. The psychological and social stigma associated with severe facial deformity makes this syndrome one of the most challenging reconstructive problems presented to the craniomaxillofacial surgeon.

Radiocephalometric evaluation of a family with mandibulofacial dysostosis

Persons from four generations of a family with mandibulofacial dysostosis (MFD), known as Treacher Collins (TC) Syndrome, were examined for the presence of clinical signs traditionally associated with this syndrome. In this family, 14 adults, who had been judged trait bearers by an earlier family study were included in this study. Maxillary and mandibular study models were taken of affected and unaffected family members. Panoramic cephalograms and lateral radiographs were taken. The lateral cephalograms were traced and digitized on a computer system and compared. The 117 cephalometric values of the trait bearers were compared with known standard values and nontrait bearing family members. In the trait bearing group, 81 of the 117 values and, in the nontrait bearing group, 72 of the 117 values were significantly different (p < 0.05) when comparing mean values to the accepted normal range. The interfamily comparison between trait-bearing and nontrait members revealed nine values to be significantly different. This indicates that cephalometric analysis of these patients, some of whom have minimal clinical expression of the gene, may have potential value for screening and further characterization of this condition. The results also suggest that intrafamily comparisons may be of greater value for diagnostic confirmation of TC than comparison with literature norms.

Mandibulofacial dysostosis: CT findings of the temporal bones

Six patients of two families with clinically suspected and genetically proven Treacher Collins syndrome and hearing loss were studied by CT of the temporal bone. The objective of this study was to detect the abnormalities and to show the variation of expression of abnormalities. We found a high incidence of asymmetry in the different ear malformations and a slightly lower incidence of some other classical features, probably due to our patient selection.

Prenatal sonographic diagnosis of Treacher Collins syndrome: a case and review of the literature

We report the prenatal ultrasonographic diagnosis of a fetus with mandibulofacial dysostosis (Treacher Collins syndrome). Sonographic findings included: polyhydramnios, microcephaly, abnormal fetal facial features (slanting forehead, microphthalmos, micrognathia), and abnormal fetal swallowing. A review of the current literature pertaining to prenatal diagnosis of this condition is presented.

Cranio-orbito-zygomatic measurements from standard CT scans in unoperated Treacher Collins syndrome patients: comparison with normal controls

Fourteen reproducible cranio-orbito-zygomatic measurements taken from 26 standard axial computed tomographic (CT) scans of unoperated individuals with symmetric forms of Treacher Collins syndrome (TCS) were compared to age-matched controls. The interorbital measurements of the TCS patients were at the mean when compared to their cohort group (medial and lateral orbital wall separation), while the zygomatic measurements were significantly less than normal confirming the extent of malar hypoplasia. The congenitally deficient lateral aspect of the orbits in TCS patients was confirmed by the greater than normal values measured for globe protrusion and medial orbital wall protrusion in conjunction with the diminished lateral orbital wall lengths, all of which use the lateral orbital rim as a reference point. The abnormal shape of the anterior cranial vault in patients with TCS was documented as a diminished intercoronal distance (width) and decreased cephalic length when compared to normal age-matched controls.

[Modern imaging of maxillofacial deformities]

Facial malformations make a wide chapter of maxillofacial abnormalities whose treatment needs an accurate clinical-instrumental analysis to quantify malformation entity and to agree on precise lesion classification and subsequent management. Maxillofacial abnormalities are classified as congenital, growth-related and acquired. Congenital deformities include the alterations present at birth, i.e., craniofacial stenosis, oto-mandibular syndrome. Treacher-Collins and Goldenhar syndrome, facial clefts and lip-palate clefts. Growth-related malformations include the deformities appearing during growth and which are called maxillary dysmorphosis, e.g., hemimandibular hyperplasia, prognathism, maxillary hypoplasia, etc. Acquired malformations are those remaining after trauma or cancer surgery and those which are secondary to fibrous dysplasias of the craniofacial complex. May 1990 through May 1993, forty-two patients with different malformations were examined. The malformations secondary to cancer surgery were not included in our series. A radiologic study including conventional skull radiography, teleradiography and panoramic tomography had been performed for preliminary assessment before axial CT studies and 2D and 3D reconstructions. As for our series, in 20 patients coventional radiology was exhaustive to diagnose the disorder and to supply essential elements for treatment planning while axial CT and 3D reconstructions added no further piece of information. Only in the most complex malformations and in all cases of congenital malformations was axial CT needed to assess the type, extent and entity of the malformations allowing both the diagnosis and adequate surgical planning.

[High resolution computerized tomography of the temporal bone in mandibulofacial dysostosis]

High resolution CT (HR-CT) scanning of the temporal bone was performed in three patients with a fully expressed mandibulofacial dysostosis for preoperative assessment of temporal bone abnormalities. The external auditory canal was absent in five of six ears. Scans revealed a dysplastic middle ear cleft with dysplastic and partly dislocated ossicles. The ossicles were absent in two temporal bones. In no patient was the mastoid bone pneumatised. The inner ear was affected in only one patient in whom a shortening of the lateral semicircular canal could be found bilaterally. The role of HR-CT of the temporal bone as a preoperative diagnostic tool for the assessment of abnormalities of surgical import is discussed.

Fetal micrognathia: associated anomalies and outcome

The purpose of this study was to evaluate the spectrum of sonographic findings, karyotypic abnormalities, and clinical outcome in cases of fetal micrognathia. Twenty fetuses with sonographically identified micrognathia were identified between 15 weeks' gestation and term. Five of 20 fetuses (25%) had abnormal karyotypes, including three with trisomy 18 and one each with trisomy 13 and trisomy 9. Sixteen of the 20 fetuses (80%) did not survive: Ten died in utero or during the neonatal period, and six pregnancies were terminated electively. Three of 20 fetuses (15%) had micrognathia as the sole sonographic finding. Two of these fetuses survived, one with growth retardation and one with Pierre Robin syndrome. Thirteen of 20 pregnancies were complicated by polyhydramnios. The diversity of the syndromes represented in our cases of micrognathia indicates a wide breadth of possible diagnoses when micrognathia is encountered prenatally. The poor prognosis and associated karyotypic and lethal anomalies are remarkable, with survival of only four of 20 fetuses in this report.