Broad spectrum of skeletal malformation complex in patients with cleidocranial dysplasia syndrome: radiographic and tomographic study

Cranial Base Synchondrosis: Chondrocytes at the Hub

The cranial base is formed by endochondral ossification and functions as a driver of anteroposterior cranial elongation and overall craniofacial growth. The cranial base contains the synchondroses that are composed of opposite-facing layers of resting, proliferating and hypertrophic chondrocytes with unique developmental origins, both in the neural crest and mesoderm. In humans, premature ossification of the synchondroses causes midfacial hypoplasia, which commonly presents in patients with syndromic craniosynostoses and skeletal Class III malocclusion. Major signaling pathways and transcription factors that regulate the long bone growth plate-PTHrP-Ihh, FGF, Wnt, BMP signaling and Runx2-are also involved in the cranial base synchondrosis. Here, we provide an updated overview of the cranial base synchondrosis and the cell population within, as well as its molecular regulation, and further discuss future research opportunities to understand the unique function of this craniofacial skeletal structure.

Demographic, clinical, and radiological characteristics of cleidocranial dysplasia: A systematic review of cases reported in south America

Introduction

Cleidocranial dysplasia (CCD) is a rare disease characterized by craniofacial, skeletal, and oral anomalies. The disease prevalence is estimated to be 1 per million inhabitants; thus, only a few studies have described large cohorts of CCD patients. This study reviewed the clinical-radiological and demographic characteristics of patients with CCD in South America.

Methods

We conducted a systematic review of all cases of CCD reported in South America following the PRISMA guidelines. Demographic information (sex, age at diagnosis, origin, reason for consultation, and family history) was also recorded. CCD signs were divided into “craniofacial” and “skeletal” categories.

Results

A total of 72 cases were included. We found that oral anomalies were the most common reason for consultation leading to a diagnosis in patients, with a median age at diagnosis of 14 years. Fifty percent of the patients were women. Open fontanels or cranial sutures, the presence of at least one of the typical CCD facies (frontal bossing, brachycephaly, hypertelorism, or depression of the nasal bridge), and supernumerary teeth were reported in 92%, 85%, and 88% of cases, respectively. Clavicular dysplasia was present in 98.6% of cases, and other skeletal abnormalities such as scoliosis, pubic symphysis diastasis, and flat feet were found; short stature was present in 71% of cases, and one case presented cognitive deficits.

Conclusion

Although the phenotypic spectrum of CCD is variable, clavicular dysplasia, open fontanels or cranial sutures, dental anomalies, and at least one of the typical CCD facies are present in at least 80% of cases.

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About 70% of patients are diagnosed during childhood or adolescence, mostly due to dental complications.

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Clavicular dysplasia, open fontanel, dental abnormalities, and facies typical of CCD are present in at least 80% of cases.

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The prevalence of CCD signs in the South American population is similar to other patient groups from other populations.

Posterior fossa subdural hematoma in a neonate with cleidocranial dysostosis after a spontaneous vaginal delivery: a case report

BACKGROUND

Cleidocranial dysostosis (CCD) is an anomaly characterized by delayed closure of the cranial sutures, midface hypoplasia, moderately short stature, hypoplastic or aplastic clavicles, dental abnormalities, and other complications.

CASE PRESENTATION

We report a case of posterior fossa subdural hematoma (PFSDH) after vaginal delivery in a neonate with CCD, which presented with several clinical symptoms such as apnea, vomiting, and bradycardia. Our patient, who had a family history of CCD, developed apnea and vomiting shortly after birth; PFSDH was detected by head computed tomography, and the patient recovered well following standard medical treatment.

CONCLUSION

The prognosis of intracranial hemorrhage in neonates with CCD is generally poor. In neonates, PFSDH occurs by the following mechanism: the distortion of the infant's cranium during delivery, by the strong force, causes elongation of the falx and angulation of the tentorium that leads to tears in the posterior fossa venous structures, which then cause bleeding into the subdural space. In CCD, the forces occurring during vaginal delivery may causeexcessive distortion of the fragile skull. An awareness of CCD is hence important to avoid vaginal delivery in prenatally diagnosed CCD cases with a family history of CCD.

New Insights Into Cranial Synchondrosis Development: A Mini Review

The synchondroses formed via endochondral ossification in the cranial base are an important growth center for the neurocranium. Abnormalities in the synchondroses affect cranial base elongation and the development of adjacent regions, including the craniofacial bones. In the central region of the cranial base, there are two synchondroses present—the intersphenoid synchondrosis and the spheno-occipital synchondrosis. These synchondroses consist of mirror image bipolar growth plates. The cross-talk of several signaling pathways, including the parathyroid hormone-like hormone (PTHLH)/parathyroid hormone-related protein (PTHrP), Indian hedgehog (Ihh), Wnt/β-catenin, and fibroblast growth factor (FGF) pathways, as well as regulation by cilium assembly and the transcription factors encoded by the RUNX2, SIX1, SIX2, SIX4, and TBX1 genes, play critical roles in synchondrosis development. Deletions or activation of these gene products in mice causes the abnormal ossification of cranial synchondrosis and skeletal elements. Gene disruption leads to both similar and markedly different abnormalities in the development of intersphenoid synchondrosis and spheno-occipital synchondrosis, as well as in the phenotypes of synchondroses and skeletal bones. This paper reviews the development of cranial synchondroses, along with its regulation by the signaling pathways and transcription factors, highlighting the differences between intersphenoid synchondrosis and spheno-occipital synchondrosis.

Sphenoid bone hypoplasia is a skeletal phenotype of cleidocranial dysplasia in a mouse model and patients

Cleidocranial dysplasia (CCD) is an autosomal dominant disorder caused by heterozygous mutations in RUNX2. Affected individuals exhibit delayed maturation or hypoplasia in various bones, mainly including those formed by intramembranous ossification. Although several reports described deformation of the sphenoid bone in CCD patients, details of the associated changes have not been well documented. Most parts of the sphenoid bone are formed by endochondral ossification; however, the medial pterygoid process is formed by intramembranous ossification associated with secondary cartilage. We first investigated histological changes in the medial pterygoid process during different developmental stages in Runx2^+/+ and Runx2^+/- mice, finding that mesenchymal cell condensation of the anlage of this structure was delayed in Runx2^+/- mice as compared with that in Runx2^+/+ mice. Additionally, in Runx2^+/+ mice, Osterix-positive osteoblastic cells appeared at the upper region of the anlage of the medial pterygoid process, and bone trabeculae appeared to associate with subsequent secondary cartilage formation. By contrast, few Osterix-positive osteoblastic cells appeared at the upper region of the anlage of the medial pterygoid process, and no bone trabeculae appeared thereafter in Runx2^+/- mice. At more advanced embryonic stages, endochondral ossification occurred at the lower part of the medial pterygoid process in both Runx2^+/+ and Runx2^+/- mice. After birth, well-developed bone trabeculae occupied two-thirds of the cranial side of the medial pterygoid process, and cartilage appeared beneath these bones in Runx2^+/+ mice, whereas thin trabecular bone appeared at the center of the cartilage of the medial pterygoid process in Runx2^+/- mice. In adult mice, the body and medial pterygoid processes of the sphenoid bone comprised mature bones in both Runx2^+/+ and Runx2^+/- mice, although the axial length of the medial pterygoid processes was apparently lower in Runx2^+/-mice as compared with that in Runx2^+/+mice based on histological and micro-computed tomography (CT) examinations. Moreover, medical-CT examination revealed that in CCD patients, the medial pterygoid process of sphenoid bone was significantly shorter relative to that in healthy young adults. These results demonstrated that the medial pterygoid process of the sphenoid bone specifically exhibited hypoplasia in CCD.

The Treatment of Cleidocranial Dysostosis (Scheuthauer-Marie-Sainton Syndrome), a Rare Form of Skeletal Dysplasia, Accompanied by Spinal Deformities: A Review of the Literature and Two Case Reports

Cleidocranial dysostosis is a skeletal dysplasia inherited in an autosomal dominant manner and may lead to complications such as scoliosis and kyphosis, concurrent with various orthopedic involvements. Since concurrent spinal deformities are of progressive nature, surgical treatment may be necessary. In addition to other orthopedic problems, possible accompanying complications such as atlanto-axial subluxation, myelopathy, syringomyelia, congenital spine deformities, spondylosis, and spondylolisthesis should be kept in mind while planning for the treatment of scoliosis and kyphosis. Lengthening the use of growth-friendly systems (growing rod) in patients, like ours, with an early onset of symptoms, and performing posterior instrumentation and fusion once the spinal growth is complete will yield successful results with no complications in the middle and the long term. Further multicenter studies with more comprehensive assessments are required to find solutions to spinal problems related to this rare skeletal dysplasia.

Three-dimensional imaging of soft and hard facial tissues in patients with craniofacial syndromes: a systematic review of methodological quality

OBJECTIVES

To systematically review the methodological quality of three-dimensional imaging studies of patients with craniofacial syndromes and to propose recommendations for future research.

METHODS

PubMed, Embase and Cochrane databases as well as Grey literature were electronically searched. Inclusion criteria were patients with genetic syndromes with craniofacial manifestations and three-dimensional imaging of facial soft and/or hard tissues. Exclusion criteria consisted of non-syndromic conditions or conditions owing to environmental causes, injury or trauma, facial soft and hard tissues not included in the image analysis, case reports, reviews, opinion articles. No restrictions were made for patients' ethnicity nor age, publication language or publication date. Study quality was evaluated using the Methodological Index for Non-Randomized Studies (MINORS).

RESULTS

The search yielded 2228 citations of which 116 were assessed in detail and 60 were eventually included in this review. Studies showed a large heterogeneity in study design, sample size and patient age. An increase was observed in the amount of studies with time, and the imaging method most often used was CT. The most studied craniofacial syndromes were Treacher Collins, Crouzon and Apert syndrome. The articles could be divided into three main groups: diagnostic studies (34/60, 57%), evaluation of surgical outcomes (21/60, 35%) and evaluation of imaging techniques (5/60, 8%). For comparative studies, the median MINORS score was 13 (12-15, 25-75th percentile), and for non-comparative studies, the median MINORS score was 8 (7-9, 25-75th percentile).

CONCLUSIONS

The median MINORS scores were only 50 and 54% of the maximum scores and there was a lack of prospective, controlled trials with sufficiently large study groups. To improve the quality of future studies in this domain and given the low incidence of craniofacial syndromes, more prospective multicentre controlled trials should be set up.

Metatropic dysplasia-a skeletal dysplasia with challenging airway and other anesthetic concerns

BACKGROUND

Metatropic dysplasia is a rare form of skeletal dysplasia requiring multiple anesthetics for surgical and imaging procedures, most of which are orthopedic procedures. We provide centralized care to patients with skeletal dysplasia at our tertiary care pediatric hospital, and we were able to collect the largest number of metatropic dysplasia patients reported to date.

AIM

The aim of this retrospective study was to describe and characterize the anesthetic difficulties in this high-risk population.

METHODS

Medical charts of all patients with metatropic dysplasia were reviewed to collect data, including anesthetics performed, difficulties, and complications related to the anesthetic care, co-morbid conditions, and related events.

RESULTS

Twenty-three patients with metatropic dysplasia underwent 188 anesthetics with 61% of the anesthetics having been administered for orthopedic procedures. Fourteen of 23 (60.8%) progressively became difficult to intubate over the course of their care, with 12 out of 14 having undergone cervical spine fusion. These 14 patients had a total of 133 procedures. Sixty procedures (45.1%) had an airway described as difficult. Glidescope was the difficult airway tool most commonly used (68%) with flexible fiberoptic scope used 12% and Miller or Macintosh blade used 18% of the time. In addition to the airway difficulties, spinal canal narrowing or stenosis was widely prevalent, and no neuraxial anesthetic was performed in any of our patients.

CONCLUSION

Difficult airway is the most common co-morbid condition present in patients with metatropic dysplasia, especially if their cervical spine has been fused. Familiarity with the difficulties involving the airway and its management is critical in safe and successful management of anesthesia in this high-risk population.

Neuroimaging Findings in Pediatric Genetic Skeletal Disorders: A Review

Genetic skeletal disorders (GSDs) are a heterogeneous group characterized by an intrinsic abnormality in growth and (re-)modeling of cartilage and bone. A large subgroup of GSDs has additional involvement of other structures/organs beside the skeleton, such as the central nervous system (CNS). CNS abnormalities have an important role in long-term prognosis of children with GSDs and should consequently not be missed. Sensitive and specific identification of CNS lesions while evaluating a child with a GSD requires a detailed knowledge of the possible associated CNS abnormalities. Here, we provide a pattern-recognition approach for neuroimaging findings in GSDs guided by the obvious skeletal manifestations of GSD. In particular, we summarize which CNS findings should be ruled out with each GSD. The diseases (n = 180) are classified based on the skeletal involvement (1. abnormal metaphysis or epiphysis, 2. abnormal size/number of bones, 3. abnormal shape of bones and joints, and 4. abnormal dynamic or structural changes). For each disease, skeletal involvement was defined in accordance with Online Mendelian Inheritance in Man. Morphological CNS involvement has been described based on extensive literature search. Selected examples will be shown based on prevalence of the diseases and significance of the CNS involvement. CNS involvement is common in GSDs. A wide spectrum of morphological abnormalities is associated with GSDs. Early diagnosis of CNS involvement is important in the management of children with GSDs. This pattern-recognition approach aims to assist and guide physicians in the diagnostic work-up of CNS involvement in children with GSDs and their management.

The significance of the clavicle on shoulder girdle function

BACKGROUND

Patients with cleidocranial dysplasia (CCD) can have a congenital partial or total absence of the clavicle. The aim of this study was to evaluate the functional shoulder score in these patients.

MATERIAL AND METHODS

Patients with CCD who were members of a social media group were invited to take part in an Internet-based survey. The questionnaire was composed of 3 general questions, a question concerning partial or total absence of the clavicle, and 3 patient-based shoulder scores (American Shoulder and Elbow Surgeons score; shortened Disabilities of the Arm, Shoulder, and Hand score; and patient-based Constant-Murley score).

RESULTS

Thirty-six patients (27 women, 9 men) with a mean age of 40 years participated in the survey; 17 patients had a bilateral absence, 16 patients had a bilateral partial absence, and 3 patients had a total absence on one side and a partial absence of the clavicle on the other side. The average patient-based Constant-Murley score was 79; shortened Disabilities of the Arm, Shoulder, and Hand score, 11; and American Shoulder and Elbow Surgeons score, 93. There was no significant difference in the scores between left and right. There was no correlation between partial and total absences and the shoulder scores.

CONCLUSION

Patients with self-reported CCD are subjectively normal to their peers when they are evaluated with 3 common shoulder scores. There was no correlation between partial and total absences and the shoulder scores.