Cleidocranial dysostosis

Cleidocranial dysplasia is a rare genetic condition that affects teeth and bones, such as the skull, face, spine, collarbones, and legs. The bones in people with CCD might be formed differently or might be more fragile than normal, and certain bones such as collarbones may be absent.

Runx2, also known as Cbfa1, is a multifunctional transcription factor essential for osteoblast differentiation. It also plays a major role in chondrocyte maturation, mesenchymal stem cell differentiation, cleidocranial dysplasia, and the growth and metastases of tumors.

A review encountered several cases of orthodontic implications but a few cases on cranial defect approach.

The articles present literature that is unanimous on the recommendation of expectant conduct in children since the cranial block can occur spontaneously, even if the delayed form ¹⁾.

Hypophosphatasia (HPT) and cleidocranial dysplasia (CCD) are characterized by both defective ossification and bone mineralization. Patients usually present with craniosynostosis and cranial defects which in many cases require surgical repair.

There re only 2 reported case of combined HPT and CCD in the literature.

The reported case of Blionas et al. involves a 3.5-year-old girl with concomitant homozygous CCD and heterozygous HPT. The child had an extended cranial defect since birth which improved with the administration of Strensiq and was followed until preschool age. Bone defects were relatively minor on revaluation. Due to the limited final defect, we decided not to intervene. In HPT-CCD patients, bone defects are overestimated due to osteomalacia, and thus, management strategy should be less aggressive. They should undergo surgical repair with cranioplasty with the use of cement and/or titanium meshes in case of extended final defects ²⁾.

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.

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 cause excessive 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 ³⁾.

A 40-yr-old woman presented with sensory disturbance on the left side of the body. Magnetic resonance imaging (MRI) revealed cerebellar tonsil herniation into the foramen magnum with cervical syringomyelia, and computed tomography additionally revealed skull anomalies: fontanel closure insufficiencies, cranial dysraphism, thin cranial bone, and dentition abnormalities. We diagnosed as symptomatic CM1 with syringomyelia associated with cleidocranial dysplasia, which is a dominantly inherited autosomal bone disease. Cerebral angiography revealed a developed right occipital sinus and hypoplasia of the bilateral transverse sinus. We performed FMD, paying special attention to the developed occipital sinus using ICG-VA to ensure a safe duraplasty. The angiography clearly highlighted a right-sided occipital sinus with a high contrast ratio, and no left-sided occipital sinus was visible. After a dural incision in a unilateral curvilinear fashion was safely completed, expansive duraplasty was performed. The sensory disorders experienced by the patient disappeared postoperatively. Postoperative MRI revealed elevation of the cerebellar tonsil and decreasing of the syringomyelia.

Conclusion: Additional assessment using intraoperative ICG-VA provides useful information for a safe FMD, particularly in patients with complicated cerebral venous circulation anomalies ⁴⁾.

A rare case of successful cranioplasty using a modified split calvarial graft technique in a patient with cleidocranial dysplasia ⁵⁾.