Impact of pediatric hematopoietic stem-cell transplantation on craniofacial growth

OBJECTIVES: To assess the craniofacial skeletal growth in pediatric hematopoietic stem-cell transplantation (HSCT) survivors in comparison with age-sex matched-paired controls. METHODS: A case-controlled retrospective comparison of the craniofacial growth in 25 HSCT children and 25 matched-paired controls was conducted. Craniofacial growth was quantitatively assessed by linear and angular measurements in panoramic radiographic images using ImageJ¯. Stature growth and body weight were obtained through physical examination. Cancer diagnosis, myeloablative conditioning, and HSCT were retrieved from medical records. RESULTS: Patients aged 12.2 years (±3.8; 16 male, 9 female). Radiographic images were obtained on an average of 2.43 (±2.0) years after HSCT. The main malignant diagnosis was acute lymphoblastic leukemia (56%), followed by acute myeloid leukemia (36%) and myelodysplastic syndromes (8%). Total body irradiation was associated with chemotherapy at 80%. Mean age at transplantation was 10 (±4.7) years. HSCT survivors showed reduced a vertical growth of the mandibular ramus (p=0.003). This persisted among individuals below 12 years of age (p=0.017). The HSCT group showed delayed dental eruption, though there was no statistically significant difference (p=0.3668). The HSCT group showed stature deficit, increased weight, and body mass index (Z-score stature: -0.28; Z-score weight: 0.38, respectively). CONCLUSIONS: Pediatric HSCT has decreased vertical craniofacial growth compared to their matched controls. There might be an association between reduced craniofacial vertical growth and reduced estature growth. Further studies to quantitatively investigate the impact of different myeloablative regimens in craniofacial skeletal growth and development.

Postnatal Development of the Anterior Skull Base and Nasal Septum: CT Study

PURPOSE: To know the normal CT appearance of the anterior skull base and nasal septum after birth. MATERIALS AND METHODS: Coronal CT scans with a helical mode were performed from the nasal bone to the sphenoid sinus in 99 children whose ages ranged from 27 days to 14 years. We investigated the CT appearance of the developing anterior skull base and nasal septum with particular attention to the anteroposterior length of the anterior skull base and the ossification patterns of the cribriform plate, perpendicular plate, crista galli, and vomer. RESULTS: The anteroposterior length of the anterior skull base statistically significantly increased with age. The cribriform plate showed partial or complete ossification in at least one segment at more than 3 months of age and in all three segments at more than 6 months of age. Ossification of the cribriform plate occurred earlier in the middle segment than in the anterior and posterior segments. It began exclusively in the region of the lateral mass of the ethmoid and proceeded medially toward the crista galli. Partial ossification of the perpendicular plate was noted as early as 9 months of age, and complete ossification as early as 13 months of age. All children at 18 months and older showed at least partial ossification of the perpendicular plate. Partial ossification of the crista galli was noted as early as 27 days of age, and complete ossification as early as 3 months of age. CT showed complete ossification of the crista galli in all but two children at 6 months and older. The superior aspect of the vomer exhibited a V- or Y-shape on all CT scans in 66%(65/99) of children at any age. It appeared as an undivided single lump anteriorly and a V or Y posteriorly in 34%(34/99). CONCLUSION: Knowledge of the normal developing patterns of ossification of the anterior skull base and nasal septum could help prevent errors in interpreting CT scans in this region, especially in infants and young children.

Normal Development of Sutures and Synchondroses in the Central Skull Base: CT Study

PURPOSE: To evaluate the developmental patterns of the sutures and synchondroses in the central skull base. MATERIALS AND METHODS: We evaluated the CT scans of 109 children(age range, 29 days to 15 years) with no skull base abnormality who had undergone axial CT of the skull base with 1-mm collimation. Using a five-tier scheme, we analyzed the developmental patterns of the 18 sutures and synchondroses related to the sphenoid and occipital bones. RESULTS: Fusion of the sutures and synchondroses related to the sphenoid bone progressed rapidly during the first two years. Thereafter, changes in the sphenoid bone were dominated by pneumatization of the sphenoid sinus. Fusion of the synchondroses within the sphenoid body, including intersphenoidal, intrapresphenoidal, and intrapostsphenoidal synchondrosis occurred early and in most cases was graded <=4. Fusion of the sphenosquamosal, sphenoethmoidal, and frontosphenoidal sutures was delayed, and residual sclerosis was a common finding. Except for Kerckring-supraoccipital synchondrosis, fusion of the six sutures and synchon-droses related to the occipital bone occurred more gradually than that of those related to the sphenoid bone. Among these, fusion of the occipitomastoidal suture and petro-occipital synchondrosis was the last to occur. CONCLUSION: A knowledge of the developmental patterns of sutures and synchondroses can help differentiate normal conditions from those such as fracture, osseous dysplasia, or congenital malformation, which are abnormal. Our results provide certain basic informations about skull base maturity in children.