A quantitative assessment of the healing of intramembranous and endochondral autogenous bone grafts.
The aim of the study was to assess quantitatively the amount of new bone formed in the early stages of healing of intramembranous and endochondral autogenous bone grafts so as to gain further insight into their integration with host bone. Eighteen critical size defects were created in the parietal bone of nine New Zealand White rabbits. In the experimental group (five rabbits), each rabbit was grafted with intramembranous bone in one defect and with endochondral bone in the other. In the control group (four rabbits), one defect was left empty (passive control) and the other was grafted with rabbit skin collagen (active control). After 14 days, the rabbits were killed and the defects were prepared for histological analysis. Serial sections were made across the whole defect. Each defect was divided into five regions spaced 1500 microns apart. Two sections were randomly drawn from each region. Quantitative analysis was performed on 100 sections using an image analyser computer software system to assess the amount of new bone formed in each defect. No bone was detected across the defect in either the active or passive controls. One-hundred-and-sixty-six per cent more new bone was formed in defects grafted with intramembranous bone than those grafted with endochondral bone. This represented an extremely significant difference (P < 0.0001, unpaired t-test) between the two groups. The results show that intramembranous autogenous bone produced more bone than the endochondral bone when grafted in the skull. Clinically, it is recommended that intramembranous bone is used to replace lost membranous bone in the oral cavity, as well as in skull defects, whenever possible. (+info)
Biometrical threshold of biparietal diameter for certain fetal sex assignment by ultrasound.
OBJECTIVES: The aim of this study was to establish the biometric threshold of biparietal diameter (BPD), assumed to be an independent variable of gestational age, at which 100% accuracy in the assessment of fetal sex by ultrasonography is achievable. METHODS: Transvaginal and/or transabdominal sonography was used for detecting the 'sagittal sign' as a marker of fetal sex in 385 fetuses with BPD between 18 and 29 mm. The results of ultrasound examination were compared with sex at birth or with karyotype obtained from amniotic fluid cells or chorionic villus sampling. RESULTS: Fetal sex assignment was feasible in 337 of 385 cases (87.5%). Of the 312 fetuses with known fetal sex outcome, 164 were males and 148 were females. An accuracy rate of 100% was achieved when a BPD of > or = 23 mm was obtained. CONCLUSION: This study provides important information about the earliest stage of fetal development, expressed in terms of BPD, at which a diagnosis of fetal sex can be made with 100% accuracy. (+info)
Molecular and clinical examination of an Italian DEFECT11 family.
The DEFECT11 syndrome is a contiguous gene syndrome associated with deletions in the proximal part of chromosome 11p. In this study, we describe in an Italian family the co-existence of multiple exostoses (EXT) and enlarged parietal foramina (FPP), the two major symptoms of this syndrome, with abnormalities of the central nervous system. The latter may be a yet undescribed feature of DEFECT11 syndrome. FISH and molecular analysis allowed us to identify a small deletion on 11p11-p12, further refining the localisation of the FPP gene involved in the DEFECT11 syndrome. (+info)
Fetal acalvaria with amniotic band syndrome.
A case of amniotic band syndrome (ABS) presenting with acalvaria is reported. ABS includes a spectrum of non-genetic anomalies, varying from simple digital band constriction to major craniofacial and visceral defects, and even fetal death. Acalvaria is a rare congenital malformation characterised by the absence of the dome-like superior portion of the cranium comprising the frontal, parietal, and occipital bones and dura mater, in the presence of a normal skull base and facial bones with complete cranial contents. No two cases are the same. Acrania or absence of the flat skull bones with disorganised cerebral hemispheres have been reported in the presence of amniotic bands. ABS is an aetiological factor in acalvaria. Appropriate counselling for affected families needs to be given after prenatal diagnosis. (+info)
Identification of mutations in the MSX2 homeobox gene in families affected with foramina parietalia permagna.
Foramina parietalia permagna (FPP) is an autosomal dominant condition characterized by cranial defects of the parietal bones. It can be present as an isolated feature, but it is also one of the characteristics of a contiguous gene syndrome associated with deletions on chromosome 11p11-p12. One of the proteins known to be involved in skull development is the MSX2 homeobox protein. Previously, MSX2 has been shown to be mutated in patients suffering from Boston type craniosynostosis. We have now analyzed the MSX2 gene in five families affected with FPP. An intragenic microsatellite marker did not reveal any recombination and a cumulated LOD score of +3.2 at theta = 0 was obtained. Sequence analysis further showed that in four out of five families an MSX2 mutation was responsible for the skull defect. Moreover, it appears that FPP is caused by haplo-insufficiency of the MSX2 gene. This implies that Boston type craniosynostosis and FPP are allelic variants of the same gene, with FPP caused by loss of MSX2 function and craniosynostosis Boston type due to gain of MSX2 function. (+info)
Magnetic resonance imaging of calvarial eosinophilic granuloma with pericranial soft tissue reaction--case report.
A 4-year-old girl presented with an eosinophilic granuloma in the cranial vault. Magnetic resonance (MR) imaging showed the mass as slightly low intensity on T1- and high intensity on T2-weighted images. The pericranial soft tissue was densely enhanced after gadolinium-diethylenetriaminepenta-acetic acid infusion. The mass was soft and successfully removed. Histological examination disclosed Langerhans' cell histiocytosis. MR imaging is useful for the diagnosis of calvarial eosinophilic granuloma with soft tissue involvement. (+info)
Location of the glenoid fossa after a period of unilateral masticatory function in young rabbits.
Changes in glenoid fossa position and skull morphology after a period of unilateral masticatory function were studied. The right-side maxillary and mandibular molars in twenty-seven 10-day-old rabbits were ground down under general anaesthesia. The procedure was repeated twice a week, until the rabbits were 50 days old. Fourteen rabbits were then killed and 13 left to grow to age 100 days. Nine 50-day-old and sixteen 100-day-old rabbits with unmodified occlusions served as controls. Three-dimensional measurements were made using a machine-vision technique and a video-imaging camera. The glenoid fossa position become more anterior in both groups of animals subjected to molar grinding as compared with controls (P < 0.01 in the 50-day-old group and P < 0.05 in 100-day-old group). In the 100-day-old group the right-side fossa was also in a more inferior position (P < 0.01). The glenoid fossa was more anteriorly located on the right than on the left side of individual animals in the group in which the right-side molars had been ground down (P < 0.001). (+info)
Haploinsufficiency of ALX4 as a potential cause of parietal foramina in the 11p11.2 contiguous gene-deletion syndrome.
Heterozygous mutations in MSX2 are responsible for an autosomal dominant form of parietal foramina (PFM). PFM are oval defects of the parietal bones that are also a characteristic feature of a contiguous gene-deletion syndrome caused by a proximal deletion in the short arm of chromosome 11 (Potocki-Shaffer syndrome). We have identified a human bacterial artificial chromosome (BAC) clone mapping to chromosome 11, containing a region homologous to the human homeobox gene MSX2. Further sequence analysis demonstrated that the human orthologue (ALX4) of the mouse Aristaless-like 4 gene (Alx4) is contained within this 11p clone. We used FISH to test for the presence-or for the heterozygous deletion-of this clone in two patients with the 11p11.2-deletion syndrome and showed that this clone is deleted in these patients. ALX4 and Alx4 were shown to be expressed in bone and to be absent from all other tissues tested. The involvement of Alx4 in murine skull development, its bone-specific expression pattern, the fact that Alx4 is a dosage-sensitive gene in mice, and the localization of a human genomic clone containing ALX4 to 11p11.2, with hemizygosity in patients with deletion of 11p11.2 who have biparietal foramina, support the contention that ALX4 is a candidate gene for the PFM in the 11p11.2-deletion syndrome. (+info)