Biomedical subjects

S Kreiborg

Publications and source records attributed to S Kreiborg.

At least 19 recordsLinked to original sources

PubMed1992

Upper and lower airway compromise in the Apert syndrome.

Both upper and lower airway compromise may be responsible for early death in some patients with the Apert syndrome. We report on two and review six cases with complete or partial cartilage sleeve abnormalities of the trachea. Possible mechanisms include tracheal stenosis and/or lack of tracheal distensibility which may result in respiratory inefficiency, inability to clear secretions, and/or increased liability to surface injury from tracheal suctioning. Upper airway compromise, consisting of obstructive sleep apnea and cor pulmonale, may result from reduced nasopharyngeal and oropharyngeal dimensions in the Apert craniofacial configuration.

Acrocephalosyndactylia↗

PubMed1992

Cervical spine in the Apert syndrome.

Radiographs of the cervical spine--in many cases longitudinal--were available for study in 68 cases of Apert syndrome. Autopsy material was available in one of these cases, and a 3-dimensional reconstruction from a CT scan was also studied in one case. Variable degrees of fusion were observed, involving the articular facets, the neural arch or transverse processes, or block fusion of the vertebral bodies. Ossification may not always be evident in some early radiographs. However, early radiographic signs of impending fusion may be irregularity in vertical orientation of the vertebral bodies and narrowing of the involved intervertebral spaces. Cervical fusions occurred in 68%, single fusions being found in 37%, and multiple fusions in 31%. C5-C6 fusion was most common, alone or in combination with other fusions. In contrast, cervical fusions are known to occur in 25% of Crouzon patients, most commonly involving C2-C3 only. It appears that when fusions are present, C5-C6 involvement in the Apert syndrome and C2-C3 involvement in the Crouzon syndrome separate the 2 conditions in most cases. Because cervical anomalies may complicate an already compromised airway in any form of acrocephalosyndactyly, it is imperative to initiate radiographic study of the cervical spine before undertaking anesthesia for surgery.

Acrocephalosyndactylia↗

PubMed1992

Dental treatment strategies in cleidocranial dysplasia.

Based on the findings of our recent longitudinal study on the abnormalities of the dentition in cleidocranial dysplasia (CCD), a hypothesis has been proposed, which makes it possible to predict time of onset of formation of supernumerary teeth and their location in the jaws. It was found that a diagnosis should be made early so that formation of supernumerary teeth can be diagnosed and early intervention undertaken. It should be possible to diagnose supernumerary incisors at about 5-7 years of age and supernumerary canines and premolars a few years later. When root length of the normal permanent teeth has reached about one third of its final length, the overlying supernumerary teeth should be removed, together with overlying bone and primary teeth. In regions where no supernumerary teeth are formed, eruption may also be improved by removal of the primary teeth and surgical exposure of the underlying permanent teeth. Conventional orthodontic treatment and eventually autotransplantation of teeth may still be necessary in the future, but it can be anticipated that the new strategy, with much earlier intervention, will materially reduce the extent of surgical and orthodontic interventions, which have previously been of extremely long duration, tedious to the patients and often of limited success.

Adolescent↗

PubMed1992

Birth prevalence study of the Apert syndrome.

Estimates of the Apert syndrome birth prevalence and the mutation rate are reported for Washington State, Nebraska, Denmark, Italy, Spain, Atlanta, and Northern California. Data were pooled to increase the number of Apert births (n = 57) and produce a more stable birth prevalence estimate. Birth prevalence of the Apert syndrome was calculated to be approximately 15.5/1,000,000 births, which is twice the rate determined in earlier studies. The major reason appears to be incomplete ascertainment in the earlier studies. The similarity of the point estimates and the narrow bounds of the confidence limits in the present study suggest that the birth prevalence of the Apert syndrome over different populations is fairly uniform. The mutation rate was calculated to be 7.8 x 10(-6) per gene per generation. Apert syndrome accounts for about 4.5% of all cases of craniosynostosis. The mortality rate appears to be increased compared to that experienced in the general population; however, further study of the problem is necessary.

Acrocephalosyndactylia↗

PubMed1992

New indirect method for estimating the birth prevalence of the Apert syndrome.

An indirect method for estimating the birth prevalence of the Apert syndrome is presented. The fraction of Apert syndrome patients in large clinical surveys of all cases of craniosynostosis is calculated and the fractional component obtained is multiplied by the known birth prevalence of craniosynostosis in general. Apert syndrome makes up approximately 4% of all cases of craniosynostosis. Using a weighted average estimate, birth prevalence was calculated to be 13.7/1,000,000. The results of the indirect method compare favorably with those obtained by the direct method. Nevertheless, because the indirect method is based on a number of assumptions that are easily violated, we cannot recommend its general use except under special conditions.

Acrocephalosyndactylia↗

PubMed1992

Birth prevalence studies of the Crouzon syndrome: comparison of direct and indirect methods.

An indirect method for estimating the birth prevalence of the Crouzon syndrome is presented. The fraction of Crouzon syndrome patients in large clinical surveys of all cases of craniosynostosis is calculated and the fractional component obtained is multiplied by the known birth prevalence of craniosynostosis in general. Crouzon syndrome makes up approximately 4.8% of all cases of craniosynostosis. Using a weighted average estimate, birth prevalence was calculated to be 16.5/1,000,000. The results of the indirect method compare favorably with those obtained by the direct method. Nevertheless, because the indirect method is based on a number of assumptions that are easily violated, we cannot recommend its general use except under special circumstances.

Acrocephalosyndactylia↗

PubMed1991

[Achondroplasia: craniofacial growth in a boy followed for a 10-year period analyzed by an implant method].

The present report deals with the description of craniofacial morphology and growth in an achondroplastic boy followed for a 10-year period. The methods included roentgencephalometry, and metallic implants were inserted in both jaws. Thereby it became possible to differentiate between displacement of the jaws and their bone remodelling. The study showed that in the patient analyzed the primary cause of the worsening of the sagittal jaw relationship was to be found in the growth disturbances of the cranial base rather than in the growth of the jaws per se.

Achondroplasia↗

PubMed1991

[Development of the dentition in cleidocranial dysplasia].

The purpose of the present investigation was to describe the formation, maturation and eruption of the dentition, including supernumerary teeth in a sample of patients with cleidocranial dysplasia. The dentition was evaluated from orthopantomograms, intraoral radiographs, cephalometric films, surgically removed teeth and intraoral photographs in 22 patients (10 men, 12 women), aged 3.5 to 34 years. Formation of primary teeth was normal, whereas all patients but one had supernumerary permanent teeth. Frequency of supernumerary teeth ranged from 22% in the maxillary incisor region to 5% in the molar regions. Anterior to the molar region supernumerary teeth were formed lingually and occlusally to the normal teeth. Maturation of the primary dentition was normal, while permanent teeth were delayed from 1 to 4 years. Supernumerary teeth were delayed about 4 years in relation to normal permanent teeth. Eruption of primary teeth was normal, whereas all patients had severe eruption problems of permanent teeth.(ABSTRACT TRUNCATED AT 250 WORDS)

Cleidocranial Dysplasia↗

PubMed1991

The infant Apert skull.

During early infancy, the Apert skull is literally wide open. It is characterized by a gaping midline calvarial defect that extends almost from the root of the nose through the metopic suture area, anterior fontanelle, and sagittal suture area to a widely patent posterior fontanelle. Only the coronal suture area is prematurely fused. During the first 2 to 4 years of life, bony islands that have formed in the midline enlarge and coalesce, obliterating the midline calvarial defect without any evidence of suture formation.

Acrocephalosyndactylia↗

PubMed1991

Agenesis of the corpus callosum. Its associated anomalies and syndromes with special reference to the Apert syndrome.

Agenesis of the corpus callosum may be associated with a variety of central nervous system (CNS) and non-CNS abnormalities and is known to occur in a number of specific syndromes. It can be a marker for several inherited metabolic disorders. Study of the Apert syndrome shows a recurrent pattern of CNS abnormalities, including defects of the corpus callosum and limbic structures, megalencephaly, misshapen brain, distortion ventriculomegaly, and gyral anomalies.

Acrocephalosyndactylia↗

PubMed1991

Craniofacial characteristics of Proteus syndrome: two modes of abnormal growth.

The dysmorphic growth patterns of the craniofacial skeleton are summarized in five patients with the Proteus syndrome. Two different modes of abnormal growth are present. One mode involves focal overgrowth of membrane bones, producing multiple hyperostoses which result in progressive craniofacial disfigurement and asymmetry. The second mode involves overgrowth of cartilage in the condyle, resulting in dentofacial asymmetry. The phenotype of the craniofacial skeleton results from both processes. In terms of appearance, the mode involving hyperostosis seems more dramatic in most cases than the mode involving cartilage.

Adolescent↗

PubMed1991

[Juvenile chronic arthritis. A clinical and radiographic study of the chewing apparatus].

The present investigation of a relatively large Danish sample of patients with Juvenile Chronic Arthritis (JCA) revealed high frequencies of symptoms from the masticatory apparatus. 63% of the patients had destructive changes in the region of the mandibular condyles caused by arthritis. In one third of these cases the destructions were severe. Three fourth of the patients with TMJ-affection showed bilateral affection, and one fourth had unilateral affection. TMJ-affection was positively correlated to the duration and the severity of the general disease at the time of examination. Fifty per cent of the patients with TMJ-affection had reduced mouth opening capacity and most of these patients were aware of the problem themselves. The frequency of other symptoms from the TMJ and the jaw musculature was relatively high in the patient group. However, there were no significant differences between these frequencies when the group with TMJ-affection was compared to the group without TMJ-affection except for mouth opening capacity. The patients with TMJ-affection had significantly higher frequencies of frontal and lateral open bite and midline devition when compared to the patients without TMJ-affection. Furthermore, the patients with TMJ-affection had a significantly higher frequency of crowding in the mandibular incisor region than the patients without TMJ-affection. Thus, the study showed that TMJ-affection is common among children with juvenile chronic arthritis, and that the TMJ-affection may result in both functional problems and malocclusion.

Arthritis, Juvenile↗

PubMed1990

The central nervous system in the Apert syndrome.

In this paper, we present available central nervous system data from our series of patients with the Apert syndrome. Combining our own data with that available in the literature, 30 patients had malformations of the corpus callosum, the limbic structures, or both. Other frequent findings included megalencephaly (7 cases), gyral abnormalities (8 cases), encephalocele (4 cases), pyramidal tract abnormalities (2 cases), hypoplasia of cerebral white matter (4 cases), and heterotopic gray matter (2 cases). Progressive hydrocephalus seems to be uncommon and has frequently been confused with nonprogressive ventriculomegaly in the past. Psychometric evaluations, neurological findings, and neuropathologic reports from the literature are critically reviewed. It is clear that a significant number of patients with the Apert syndrome are mentally retarded. It is suggested that malformations of the central nervous system may be responsible for most cases.

Acrocephalosyndactylia↗

PubMed1990

Germinal mosaicism in Crouzon syndrome.

Two sibs with classic Crouzon syndrome of the same mother but different fathers are presented as an example of germinal mosaicism in a known autosomal dominant disorder. The mother and both fathers were completely normal.

Adult↗

PubMed1990

Facial growth and oral function in a case of juvenile rheumatoid arthritis during an 8-year period.

The present report is a detailed analysis of facial growth and oral function in a girl with juvenile rheumatoid arthritis of the temporomandibular joints. She was followed from 9 to 17 years of age prior to and after orthognathic surgery. Facial growth was assessed by facial photographs, dental casts, and roentgencephalometry, and oral function was assessed clinically by electromyography, kinesiography, and bite force. In addition, histological and histochemical analysis was performed on biopsy material from her masseter muscle obtained at the time of surgery. The study showed a clear relationship between facial growth and oral function. Dysplastic growth of the mandible led to an increasingly unstable occlusion with poor working conditions for the masticatory muscles. The muscles became weak, and even revealed marked structural histological and histochemical changes. Based on these observations it is suggested that the conventional treatment strategy with postponement of orthodontic or orthognathic surgical treatment until cessation of growth is abandoned and that early treatment should be undertaken to maintain occlusal stability throughout the growth period.

Arthritis, Juvenile↗

PubMed1990

Development of the dentition in cleidocranial dysplasia.

The purpose of the present investigation was to describe the formation, maturation and eruption of the dentition, including supernumerary teeth in a sample of patients with cleidocranial dysplasia. The dentition was evaluated from orthopantomograms, intraoral radiographs, cephalometric films, surgically removed teeth and intraoral photographs in 19 patients (9 men, 10 women), aged 3.5 to 34 years. Formation of primary teeth was normal, whereas all patients but one had supernumerary permanent teeth. Frequency of supernumerary teeth ranged from 22% in the maxillary incisor region to 5% in the molar regions. Supernumerary teeth were formed lingually and occlusally to the normal teeth. Maturation of the primary dentition was normal, while permanent teeth were delayed from 1 to 4 yr. Supernumerary teeth were delayed about 4 years in relation to normal permanent teeth. Eruption of primary teeth was normal, whereas all patients had severe eruption problems of permanent teeth. It was hypothesized that the dental lamina for both primary and permanent dentition is normal, but does not resolve completely and therefore may form supernumerary teeth. Abnormalities of tooth morphology is related to inadequate space and arrested eruption. Delayed or arrested eruption is probably caused by diminished resorption of bone and of primary teeth and to the presence of multiple supernumerary teeth.

Adolescent↗

PubMed1990

Structure and function of masticatory muscles in a case of muscular dystrophy.

Histologic examination of muscle biopsies and functional examination comprising electromyography and force measurements in a 19-yr-old boy with muscular dystrophy showed different wasting patterns of mandibular elevator and depressor muscles. Pronounced histopathologic changes were present in the masseter muscle, whereas pathologic findings in the anterior digastric muscle were limited to increased number of cells in slightly enlarged interfiber connective tissue. The masticatory pattern was distorted, and strength of mandibular elevator muscles was less than one third of the norm, whereas depressor strength corresponded more to reference values. This difference of muscular wasting might be caused by protective enzymes in the digastric muscle and/or functionally induced damage of the masseter. As affection from muscular dystrophy may vary greatly between the masticatory muscles, structural and functional examination should be used routinely to clarify prognosis before initiation of treatment procedures.

Adult↗

PubMed1990

Characteristics of the infant Apert skull and its subsequent development.

The purpose of the paper is to describe and analyze the infant Apert skull with emphasis on the calvaria and its early postnatal development. Skull radiographs of 16 Apert syndrome patients were examined (12 American, 4 Danish; 8 males, 8 females). The criterion for inclusion in the study was that the first skull film had to be obtained before 1 year of age. Study methods employed included plain skull radiographs, roentgencephalometric films in several projections, CT-scans, and 3-D reconstructions. Data from 2 dry skulls and 2 early cases from the literature were also evaluated The following findings were common to all cases during early infancy (less than 3 months): The coronal suture area was prematurely closed and was represented by a bone condensation line beginning at the cranial base, extending upwards, and having a characteristic posterior convexity. Anterior and posterior fontanelles were widely patent. The midline of the calvaria had a gaping defect which extended from the glabellar area to the posterior fontanelle via the metopic suture area, anterior fontanelle, and sagittal suture area. Bony islands of varying sizes were observed in the midline defect. The calvaria was hypomineralized. During the first 2-4 years of life, the midline defect was obliterated by coalescence of the enlarging bony islands without evidence of any proper formation of sutures. The calvaria became thicker with time and several cases developed increased digital markings and enlargement of the sella turcica. During infancy, the Apert skull with its gaping midline defect appears to permit adequate accommodation of the growing brain, albeit distorted in shape. Normal metopic, sagittal, and coronal sutures with interdigitations were not observed in a single instance; in contrast, the lambdoidal sutures appeared normal in all cases. The invariable findings of an extremely short squama and orbital part of the frontal bone together with the posterior convexity of the coronal bone condensation line suggest that growth inhibition in the sphenofrontal and coronal suture area has its onset very early in fetal life.

Acrocephalosyndactylia↗