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Biomedical subjects

S Kreiborg

Publications and source records attributed to S Kreiborg.

103 records · Page 6Linked to original sources
PubMedDate not supplied

Anomalies of craniofacial skeleton and teeth in cleidocranial dysplasia.

Mutations involving the transcription factor CBFA1 cause cleidocranial dysplasia (CCD) in man. Recently, a mouse model of CCD has been generated (Cbfal +/-) [Komori et al., 1997], and disturbances of osteoclast differentiation have been documented. It has been shown that these animals exhibit hypoplastic clavicles and nasal bones, and retarded ossification of parietal, interparietal, and supraoccipital bones. Humans with CCD show all these features, including severely retarded ossification of the cranial base, strongly suggesting that both intramembranous ossification and endochondral ossification are affected. In addition, CCD patients have multiple supernumerary teeth and delayed tooth eruption. The present report presents 3D reconstructions of computerised tomography (CT) scans of the craniofacial region of a CCD boy examined at both 1 and 7 years of age. The anomalies in craniofacial skeleton and teeth are analysed and compared to the findings of our previous clinical studies and to the findings in the animal model. Based on the available information, we suggest that osteoblast, osteoclast, and dentinoclast differentiation may be disturbed in CCD.

Child↗
PubMedDate not supplied

A comparison of the craniofacial morphology in 2-month-old unoperated infants with unilateral complete cleft lip and palate, and unilateral incomplete cleft lip.

This paper reports a cephalometric analysis of the craniofacial morphology in infants with unoperated unilateral complete cleft lip and palate (UCCLP) and unoperated unilateral incomplete cleft lip (UICL). The purpose of the study was to determine the nature and extent of the craniofacial deviations in UCCLP as compared to the morphology in UICL, which has previously been shown to be close to normal. The samples comprised 82 infants with UCCLP (58 males and 24 females) and 75 with UICL (48 males and 27 females). The mean age was about 2 months in both groups. The cephalometric analysis of craniofacial morphology included the lateral, frontal, and axial projections. The data were presented as mean plots of the craniofacial region including the calvaria, cranial base, orbits, nasal bone, maxilla, mandible, cervical column, pharynx, and soft-tissue profile. The most pronounced deviations in the UCCLP group were observed in the maxillary complex and the mandible. The most striking findings were: markedly increased width of the maxilla, a short mandible, and bimaxillary retrognathia except for the premaxillary area, which was relatively protruding and asymmetric. The study did not support the hypothesis previously suggested in the literature that cleft lip and palate is a craniofacial anomaly as size and shape of the calvaria and cranial base were found to be normal. The etiology of cleft lip and palate is still incompletely understood. Based on the present study, we suggest that facial type may be a liability factor that could represent a developmental threshold increasing the probability of cleft lip and palate.

Anthropometry↗
PubMedDate not supplied

Craniofacial growth in subjects with unilateral complete cleft lip and palate, and unilateral incomplete cleft lip, from 2 to 22 months of age.

This paper reports a longitudinal quantitative cephalometric analysis of the craniofacial growth in subjects with unilateral complete cleft lip and palate (UCCLP), and unilateral incomplete cleft lip (UICL), from 2 to 22 months of age. The purpose of the study was to determine the amount and direction of growth in UCCLP compared to UICL (control group) from 2 months of age (just prior to lip repair) to 22 months of age, 20 months later. The sample comprised of 49 subjects with UCCLP (37 males and 11 females) and 45 with UICL (29 males and 16 females). The cephalometric analysis of the craniofacial morphology included lateral, frontal, and axial projections. The data were presented as mean plots of the craniofacial region including the calvaria, cranial base, orbits, nasal bone, maxilla, mandible, cervical column, pharynx, and soft-tissue profile. A valid common coordinate system (registration according to the n-s line in the lateral projection, latero-orbitale line in the frontal projection, and meatus acusticus externus line in the axial projection for the landmark positions at examination 1 and 2) was ascertained. The growth at a specific anatomical location in a patient was defined as the displacement vector from the coordinate of the corresponding landmark in the X-ray at examination 1 to its coordinate at examination 2, corrected for X-ray magnification. The growth of an anatomical region in a patient was assessed by investigating the growth pattern formed by a collection of individual growth vectors in that region. The amount of growth in the UCCLP and UICL group was very similar. The general craniofacial growth pattern, in terms of the direction of growth, was also fairly similar in the UCCLP group and the control group. However, the maxilla and mandible showed a more vertical growth pattern than that observed in the control group. This study confirms that UCCLP is a localized deviation, and not a craniofacial anomaly, due to the fact that a normal growth potential has been observed in all craniofacial regions, except where the growth had been directly influenced by surgical intervention. Furthermore, the vertical growth pattern of the maxilla and mandible supports the hypothesis of a special facial type in cleft lip and palate individuals, and the facial type as a liability factor increasing the probability of cleft lip and palate.

Cleft Lip↗
PubMedDate not supplied

The oral manifestations of Apert syndrome.

As part of an ongoing study of 119 patients with the Apert syndrome, extensive data were available for the analysis of oral manifestations, including mouth shape, lip posture, palatal morphology, dental anomalies, and malocclusion. Findings included a characteristic trapezoidal-shaped mouth. Cleft soft palate or bifid uvula was found in approximately 75%. A Byzantine-arch shaped palate was recorded in almost all patients. Dental anomalies included severely delayed eruption, ectopic eruption, and shovel-shaped incisors. Malocclusion tended to be severe with mesial molar occlusion, mandibular overjet, anterior and posterior crossbites, and severe crowding of teeth. The oral manifestations of Apert syndrome are compared and contrasted with those of Crouzon syndrome.

Acrocephalosyndactylia↗
PubMedDate not supplied

Genetic and family study of the Apert syndrome.

Of 119 patients with the Apert syndrome, 94 pedigrees are available for study. Selected family histories and recorded events during pregnancy are also reported. The sex ratio is 1:1 (60 males, 59 females). All 94 pedigrees except one (an affected father and daughter) represent sporadic instances. Combining our cases with those available in the literature, only nine familial instances are known to date. The familial cases, the equal number of affected males and females, and the increased paternal age in sporadic cases strongly suggest autosomal dominant inheritance. The rarity of familial instances can be explained by reduced genetic fitness of affected individuals because severe malformations and the presence of mental deficiency, found in many cases, diminish desirability as mates. The variability of the syndrome has been defined mainly on the basis of sporadic cases. High resolution banding was normal in five recently studied cases.

Acrocephalosyndactylia↗
PubMedDate not supplied

Craniofacial growth in cleidocranial dysplasia--a roentgencephalometric study.

The purpose of this study was to analyze craniofacial growth in cleidocranial dysplasia (CCD) with emphasis on bone remodeling, mandibular condylar growth, and tooth eruption. Skull radiographs of 22 CCD children followed longitudinally were examined. The span of time investigated varied for each patient, but the period from 5 years to adult age was well covered. Five patients had metallic implants inserted in the jaws; the implants enabled detailed analysis of bone remodeling, jaw rotation, and tooth eruption. In the calvaria, an open anterior fontanelle area persisted in most cases but decreased with age. A frontal sinus failed to develop or was diminutive in all cases but one. In the cranial base, the size increase of the sella turcica was reduced as a result of modest resorption at the floor and the posterior wall; the clivus was flexed in most cases, but the flexion remained stable during the observation period. Growth in maxillary height was severely reduced, primarily because resorptive lowering of the nasal floor was minimal. The amount of bone apposition on the orbital floor and the alveolar process was smaller than expected. Condylar growth direction was vertical giving rise to a forward rotation of the mandible in relation to the anterior cranial base. The expected resorptive remodeling below the mandibular angle and anteriorly on the ramus was negligible. The low maxilla, in combination with a marked forward mandibular rotation in cases with unstable occlusion as a consequence of eruption problems in the permanent dentition, gave rise to a diminished anterior facial height.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Cranial size and configuration in the Apert syndrome.

The cranial size and configuration of the Apert cranium are unique. True megalencephaly is characteristic, postmortem brain weights being dramatically increased above the 95th centile regardless of age. In addition, all Apert newborn infants have coronal synostosis with a widely patent midline calvarial defect. Thus, the head is unusually heavy and the cranium is disproportionately high. These characteristics, which are present at birth, result in a mean newborn length and weight above the 50th centile. The widely patent midline calvarial defect, allowing the brain to expand anteriorly into the metopic area, and some increase in the head breadth permit the mean head circumference at birth to normalize slightly above the 50th centile. In our series of surgically unoperated patients of different ages from the 1960s and earlier, most head circumference values fall below the mean but within or at -2 SD. Thus, the natural history of the unoperated growing cranium, beginning slightly above the 50th centile at birth, consists of a slowing of head circumference expansion to a greater degree than normal. Studies of intracranial volume show that mean adult male and female volumes far exceed normal adult values. Cranial shape is distinctive with head breadth either being normal or slightly increased, head length being significantly shortened, and head height being dramatically increased. The mean cephalic index is hyperbrachycephalic. Sexual dimorphism is found, with higher values in females than in males; the cause is unknown, although the contributing component appears to be head breadth. The disproportionately high cranium in the Apert syndrome is dramatically shown by the great differences from normal in the head height/head breadth index and in the head height/head length index. Finally, the crania of Apert and Crouzon syndromes are compared in terms of size, shape, and volume. For Crouzon syndrome, the mean adult cephalic index is normocephalic and the mean adult intracranial volume is smaller than normal.

Acrocephalosyndactylia↗
PubMedDate not supplied

Unusual cranial aspects of the Apert syndrome.

Frank cloverleaf skull is found in approximately 4% of Apert-syndrome infants. However, the usual Apert skull and its cloverleaf form are spectral in nature. In all patients, the temporal bones are obliquely situated, and the degree to which this is so determines whether no, mild, moderate, or severe cloverleafing will occur. True encephalocele rarely is found in the Apert syndrome, but pseudoencephalocele in the frontal region sometimes is confused with it. Because the Apert calvaria at birth is characterized by a widely gaping midline defect, the midfrontal region of the brain is not covered by bone during early infancy. However, with time, closure of the midline defect occurs by coalescence of bony islands, thus covering the pseudoencephalic region. Also discussed in this paper are (a) atypical calvarial development with patency of the coronal sutures in one case, (b) size and position of the temporal muscles, and (c) size and position of the superficial temporal fat pads.

Abnormalities, Multiple↗
PubMedDate not supplied

A severe case of Pfeiffer syndrome associated with stub thumb on the maternal side of the family.

We report a severe case of Pfeiffer syndrome with an early demise. The mother and her own father had unilateral stub thumb, which was inherited as a coincidental autosomal dominant trait. Although the affected thumb was short, it was not broad and neither family member had any features of Pfeiffer syndrome. We conclude that our patient represents a new Pfeiffer syndrome mutation.

Acrocephalosyndactylia↗
PubMedDate not supplied

Development of the skull in infants with cleidocranial dysplasia.

The purpose of the present paper is to clarify some of the questions regarding pathogenesis in cleidocranial dysplasia (CCD) in order to improve the understanding of the mechanisms leading to the craniofacial abnormalities characteristic for young and adult patients with the syndrome. The neonatal skull is described and craniofacial development from birth to 7 years analyzed. Skull radiographs of 11 CCD patients ages 0-7 years were examined. Study methods included plain radiographs of the skull and roentgencephalometric films in the lateral, frontal, and axial projections. In one patient, CT scans of the skull with 3-D reconstructions were available. Common to the four patients examined within the first 6 months postnatally was a marked delay of skeletal maturity. In the calvaria a severe reduction of calcification in all bones was found. Corresponding to the expected sutural areas, gaping defects were recorded, indicating that calcification of calvarial bones in the newborn CCD individual had only reached a stage corresponding to around 20 weeks gestational age. Calvarial size corresponded to that of normal newborns and the morphology was relatively normal, taking into account the pronounced deformation that took place during parturition due to the soft, undermineralized skull. At birth bony islands could be observed in the periphery of the occipital, parietal, and frontal bones. Ossification of the maxilla and the mandible seemed to be within normal limits. Posteriorly to the foramen magnum, the chondral part of the supraoccipital bone remained unossified. In the cranial base an increased width of the spheno-occipital synchondrosis was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMedDate not supplied

Craniofacial abnormalities in 52 school-age and adult patients with cleidocranial dysplasia.

The purpose of the present investigation is to describe and discuss the craniofacial abnormalities in young and adult patients with cleidocranial dysplasia (CCD). Skull radiographs of 52 CCD patients were examined. Thirty-six patients were adult, 16 were between 7 and 16 years old. Facial photographs were available in 30 cases, and in one adult case with cranial CT scans, 3-D reconstructions were carried out. High quality photographs of six CCD skulls were also described. The paranasal sinuses were absent or diminished in all children and most adult patients. An inverted pear-shape of the calvaria and an open anterior fontanelle were present in more than 60% of the cases. In the cranial base an upward distortion of the clivus, an anteverted foramen magnum, and extremely narrow choanae were frequent traits, together with small sella and bulbous dorsum sellae. Nearly all patients and dry skulls showed hypoplasia or absence of nasal bones. The zygomatic arches were diminished or incomplete in all cases. Mandibular morphology was judged to be syndrome specific with the slender, upward-backward-pointing coronoid process. We have concluded that a great part of the abnormal qualitative traits are present to a lesser degree in CCD children, indicating a progressive abnormal development with advancing age. From the present and previous studies on CCD we have hypothesized that on top of their generalized reduction of growth potential, these patients suffer from a combination of skeletal immaturity resulting in deformations and a defective bone remodeling. We have acknowledged the importance of longitudinal investigations in order to ameliorate the understanding of the pathogenesis of CCD and thereby to improve total patient care. Correction of the craniofacial abnormalities may be advocated in the most severe cases of hypertelorism and midfrontal groove, if psychosocial problems occur. Also, patients with major midface underdevelopment might benefit from combined orthodontic/surgical correction.

Adolescent↗
PubMedDate not supplied

Histological observations of teeth and peridental tissues in cleidocranial dysplasia imply increased activity of odontogenic epithelium and abnormal bone remodeling.

Cleidocranial dysplasia (CCD) is a heritable generalized bone dysplasia presenting with a variety of dental abnormalities. To delineate morphological features of the dental tissues, we have analyzed histologically the structure of teeth and peridental tissues obtained from four CCD patients. Dentin appeared regular, except when formed in response to caries, physiological attrition or root resorption. Both acellular and cellular cementum were present in deciduous teeth, whereas in permanent teeth, cellular cementum was virtually lacking and acellular cementum was partially hyperplastic. Enamel pearls were seen in the furcations of one deciduous and one permanent molar. The roots of most deciduous teeth were resorbed only to a slight extent. Morphologically, supernumerary teeth resembled their normal counterparts. Denticles as well as epithelial cell clusters were occasionally present in the root pulps of deciduous teeth. In the peridental tissues, epithelium was locally abundant, and the cytokeratin profile confirmed its odontogenic origin. While the organization pattern of the alveolar bone matrix related to unshed deciduous teeth and unerupted permanent teeth varied, woven bone was abundant. Both formative and resorption surfaces were seen. Also, reversal lines were prominent, suggesting that the bone had, in fact, undergone remodeling. While no direct association between the aberrant bone morphology and the multifarious histological abnormalities of dental tissues can be established, the local abundance of odontogenic epithelium in peridental tissues of developing/unerupted as well as fully developed teeth may be causally related to the formation of excess acellular cementum, enamel pearls and supernumerary teeth.

Adolescent↗