The nasopharynx in infants with cleft lip and palate.

OBJECTIVE: The purpose of this study was to use three-dimensional computed tomography data and computer imaging technology to assess the skeletal components of the naso-pharyngeal area in patients with cleft lip and palate and to quantify anatomical variations. METHODS: CT scans were obtained from 29 patients of Malay origin with cleft lip and palate aged between 0 and 12 months and 12 noncleft patients in the same age group, using a GE Lightspeed Plus Scanner housed in Hospital Universiti Sains Malaysia. Measurements were obtained using the 'Persona' three-dimensional software package, developed at Australian Craniofacial Unit, Adelaide. RESULTS: The results of the present study show that there is an increased nasopharyngeal space in cleft lip and palate that may lead to compression of the nasopharyngeal structures, including the Eustachian tube. Alterations of the medial pterygoid plate and the hamulus may lead to an alteration in the origin and orientation of the tensor veli palatini muscle leading to alteration in its function. CONCLUSIONS: These anatomical variations may compromise the dilatory mechanism of the Eustachian tube, thus leading to recurrent middle ear infections in cleft children and subsequent loss of hearing.

Intracranial volume measurement of sagittal craniosynostosis.

We report 41 cases of non-syndromic isolated sagittal synostosis in which evaluation of intracranial volumes was undertaken. Twenty-six were male and fifteen were female. The measured intracranial volumes were then compared with normal age-corrected values. We have found that intracranial volumes were significantly larger than the normal population intracranial volumes in both sexes. However the statistical significance of this finding was much greater in females, (p<0.00002), than males (p<0.040), which was only of borderline significance. The results confirm smaller, earlier studies that intracranial volumes in sagittal synostosis patients are larger than average for age-corrected normal values. Analysis of a sub-set of six patients with sagittal synostosis who were found to have a common polymorphism 294C>T (Asn294Asn) in FGFR3 (fibroblast growth factor Receptor 3) on genetic testing were compared to age and sex matched cases of non-syndromic sagittal synostosis (without an underlying mutation) which confirmed that there were no discernable differences in intracranial volumes between the two groups. We conclude that this investigation supports the role of cranial re-shaping to improve cosmesis as the primary aim of surgical correction in this condition, in the absence of raised intracranial pressure.

A three-dimensional computed tomographic analysis of the cervical spine in unoperated infants with cleft lip and palate.

OBJECTIVE: To investigate anatomical variations and abnormalities of cervical spine morphology in unoperated infants with cleft lip and palate. DESIGN: Retrospective cross-sectional investigation of infants born with nonsyndromic cleft lip and palate using computed tomography scans acquired for investigation of a spectrum of clinical conditions. SETTING: Computed tomography scan data were obtained from 29 unoperated cleft lip and palate infants and 12 noncleft infants of Malay origin, ages 0 to 12 months. METHODS: Observational study of cervical spine computed tomography scans. Heights of cervical vertebral bodies (C2-C7) and intervertebral spaces were measured from landmarks identified from computed tomography reformats and three-dimensional computed tomography reconstructions. Linear modeling of heights and spaces, with age as a covariate, was undertaken to identify differences between the samples. RESULTS: Anomalous features observed in the cleft lip and palate sample included short posterior arch of C1 (2/29), abnormal development of the anterior arch of C1 (2/29), and fusions of the posterior arch of C2 and C3 (2/29). No anomalies of the cervical spine were observed in the noncleft sample. Although the heights of three cervical vertebral bodies were significantly smaller and two intervertebral spaces were significantly larger in infants with cleft lip and palate compared with noncleft infants (p < .05), overall length of the cervical spine did not differ significantly between the samples. CONCLUSION: There was evidence for subtle upper spinal anomalies in the infant cleft lip and palate population. Our finding of reduced size of some cervical vertebral bodies may reflect delayed upper spinal development in infants with cleft lip and palate.

The hyoid bone in malay infants with cleft lip and palate.

OBJECTIVE: To compare morphological and positional variations of the hyoid bone in unoperated infants with cleft lip and palate (CL/P) with those in noncleft infants. DESIGN: Retrospective, cross sectional. PATIENTS AND METHODS: Three-dimensional computed tomography scans were obtained from 29 unoperated CL/P infants of Malay origin aged between 0 and 12 months and from 12 noncleft infants in the same age range. Observations were made and measurements were obtained with a software package developed at the Australian Craniofacial Unit. The sizes of the hyoid bones and the position of the hyoid body and epiglottis in relation to the cervical spine were measured. Anatomical anomalies of the hyoid and prevalence of aspiration pneumonia were also documented. RESULTS: The hyoid bones and epiglottis were found to be located more inferiorly in CL/P infants compared with the noncleft infants. Also, 17% (5/29) of the CL/P infants had nonossified hyoid bodies. CONCLUSION: The results suggest that there are differences in the location and genesis of the hyoid bone in infants with CL/P that warrant further investigation.

Scanning electron microscope and micro-CT evaluation of cranial sutures in health and disease.

Current knowledge of suture biology has been ascertained as a result of morphological studies of normal cranial sutures (and rarely those undergoing craniosynostosis). These were initially undertaken often using histological investigations, or more recently using CT scans, as investigative tools, but have often used animal models. However, recent technological advances have provided the potential to refine our understanding of the ultrastructure by the use of new advanced scanning technology, which offers the possibility of more detailed resolution. Our aim was to undertake detailed scans of normal, fusing and fused sutures from patients with craniosynosotosis affecting different sutures, to study the detailed structure at different stages of the fusion process using a modern micro-CT scanner and a microanalytical scanning electron microscope. We wished to include in our study all the human sutures because previous studies have mostly been undertaken using the sagittal suture. Ten sutures from seven patients have revealed a complex ultra-structural arrangement. The different patterns of bone ridging seen on the ectocranial and endocranial surfaces of the fused sagittal suture were not repeated on closer inspection of either fused coronal or lambdoid sutures. Elemental analysis confirmed that the amount of calcium increased and the amount of carbon decreased as sampled areas moved away from the suture margin. We conclude that scanning allowed detailed assessment and revealed the complex arrangement of the structure of the human cranial sutures and those undergoing the process of craniosynostosis, with some differences in final structure depending on the affected suture.

Analysis of intracranial volume in apert syndrome genotypes.

OBJECTIVE: Apert syndrome is caused by a mutation of the fibroblastic growth factor type 2 gene and in nearly all of the cases where the mutation has been identified it occurs in one of two adjacent sites of the gene, either position 252 or position 253. There is currently uncertainty whether a worse neurosurgical outcome occurs in association with a particular genotype. We investigated whether there were clinically subtle (but relevant) morphological differences in the craniofacial skeleton, which would result in differences in the intracranial volume, which might account for apparent differences in surgical outcome. METHOD: Three-dimensional CT scans of pre-operative Apert syndrome whose genotype had been identified had the intracranial volume measured using the Cavalieri estimator with correction for partial voluming effects. The values were compared to age and sex normals and then the two genotypes compared. RESULTS: Intracranial volumes were measured for 22 cases, 16 with the 252 mutation and 6 with the 253 mutation. CONCLUSIONS: All cases except two had greater than their sex- and age-adjusted mean normal intracranial volumes. For the 252 and 253 genotypes there were no discernible differences in intracranial volumes between the two genotypes.

Intracranial volume measurement of metopic craniosynostosis.

The authors report 32 patients with nonsyndromic isolated metopic synostosis who have undergone evaluation of their intracranial volumes. Twenty-five were male and seven were female. The measured intracranial volumes were compared with normal age-corrected values established in the authors' unit, and any differences were noted. The authors found that, although there was a range of intracranial volumes, in the male patients, intracranial volumes were significantly smaller than those found in the normal population (P < 0.05). However, this result was not found in the smaller female sample. These results contrast with those of smaller earlier studies, but the authors conclude that intracranial volumes are smaller than average for age-corrected normal values; this finding highlights the need for volume expansion in conjunction with cranial reshaping.

Mandibular lengthening by distraction for airway obstruction in treacher-collins syndrome: the long-term results.

Mandibular lengthening by distraction was performed in a 6-year-old severely affected Treacher-Collins syndrome patient who was tracheostomy dependent. As previously reported, this procedure permitted tracheostomy removal once distraction was complete. Now that the patient is skeletally mature, the long-term results of this intervention are reported with regard to his clinical outcome and an assessment of the anatomical changes in the upper airway during growth. Although the distraction could be considered a success in that it enabled permanent decannulation and improved the minimum cross-sectional area of the upper airway, there was no further increase in the minimum cross-sectional area of the upper airway during childhood growth. It is significant that the abnormal growth pattern of the mandible, which is characteristic of this syndrome, did not alter from its preoperative pattern once distraction was completed.