Early Craniofacial Morphology and Growth in Children with Bilateral Complete Cleft Lip and Palate

Purpose

Analysis of craniofacial morphology and growth in children with bilateral complete cleft lip and palate (BCCLP), compared with a control group with unilateral incomplete cleft lip (UICL), before any treatment as well as 20 months after lip closure.

Material

The children were drawn from a group representing all Danish children with cleft born 1976 to 1981. Sixty-four children were included in the study (19 BCCLP and 45 UICL). The ages were 2 and 22 months at examinations 1 and 2, respectively.

Method

The method of investigation was infant cephalometry in three projections. The craniofacial morphology was analyzed using linear, angular, and area variables. Growth 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.

Results

The BCCLP group differed significantly from the UICL group. The most striking findings in BCCLP were an extremely protruding premaxilla; markedly increased posterior maxillary width; increased width of the nasal cavity; short maxilla with reduced posterior height; short mandible; bimaxillary retrognathia; severe reduction in the size of the pharyngeal airway; and a more vertical facial growth pattern.

Conclusion

Our findings indicate that a facial type including a wide and posterior short maxilla, short mandible, and bimaxillary retrognathia might be a liability factor that increases the probability of developing cleft lip and palate.

Early Postnatal Development of the Mandible in Children with Isolated Cleft Palate and Children with Nonsyndromic Robin Sequence

Objective

Analysis of early postnatal mandibular size and growth velocity in children with untreated isolated cleft palate (ICP), nonsyndromic Robin sequence (RS), and a control group of children with unilateral incomplete cleft lip (UICL).

Material

114 children (66 isolated cleft palate, 7 Robin sequence, 41 unilateral incomplete cleft lip) drawn from a group representing all Danish cleft children born from 1976 through 1981. All children were examined at both 2 and 22 months of age.

Methods

Cephalometric x-rays and maxillary plaster casts. Mandibular length and height were measured and mandibular growth velocity (mm/year) was calculated. Cleft width was measured on the casts at 2 months of age.

Results

Mean mandibular length and posterior height were significantly smaller in isolated cleft palate and Robin sequence, compared with unilateral incomplete cleft lip. Mandibular length in Robin sequence was also significantly shorter, compared with isolated cleft palate. No significant difference was found between mean mandibular growth velocities in the three groups. No significant correlation was found between mandibular length and cleft width in either isolated cleft palate or Robin sequence at 2 months of age.

Conclusion

The children with isolated cleft palate and Robin sequence had small mandibles shortly after birth, but with a relatively normal growth potential. No true mandibular catch-up growth was found up to 22 months of age in either group. No significant correlation was found between mandibular size and cleft width in either group at 2 months of age. However, there was a significant trend toward the shorter the mandible, the more severe the sagittal extension of the cleft.

Early post-natal development of the mandibular permanent first molar in infants with unilateral complete cleft lip and palate

OBJECTIVES

Studies have shown that the mandibular permanent first molar (M1_inf ) in young children with isolated cleft palate is characterized by delay in maturation and has reduced crown width. Consequently, it is of interest to investigate the early maturation and width of the follicle and crown of M1_inf in children with combined cleft lip and palate.

DESIGN

Retrospective, longitudinal study. Cephalometric X-rays of 47 consecutive Danish children with UCCLP (37 males; 10 females) and 44 with unilateral incomplete cleft lip (UICL) (29 males; 15 females) examined at 2 and 22 months of age. UICL served as control group. Maturation (according to Haavikko), width of follicle (FW) and crown (CW) of M1_inf were assessed.

RESULTS

The maturation of the first mandibular molar was delayed in both genders at 2 and 22 months of age. FW and CW were smaller in children with UCCLP at both 2 and 22 months of age. There was a positive correlation between maturation and FW.

CONCLUSIONS

Maturation of the first mandibular molar is delayed in both genders, and FW and CW were reduced in UCCLP compared to controls. Maturation was correlated with FW.

Novel Mutation of the Initiation Codon of PAX9 Causes Oligodontia

Tooth development is under strict genetic control. Oligodontia is defined as the congenital absence of 6 or more permanent teeth, excluding the third molar. The occurrence of non-syndromic oligodontia is poorly understood, but in recent years several cases have been described where a single gene mutation is associated with oligodontia. Several studies have shown that MSX1 and PAX9 play a role in early tooth development. We screened one family with non-syndromic oligodontia for mutations in MSX1 and PAX9. The pedigree showed an autosomal-dominant pattern of inheritance. Direct sequencing and restriction enzyme analysis revealed a novel heterozygous A to G transition mutation in the AUG initiation codon of PAX9 in exon 1 in the affected members of the family. This is the first mutation found in the initiation codon of PAX9, and we suggest that it causes haploinsufficiency.

A Pilot Study on the Influence of Facial Expression on Measurements in Three-Dimensional Digital Surfaces of the Face in Infants With Cleft Lip and Palate

OBJECTIVE

Three-dimensional surface imaging is an increasingly popular modality for face measurements in infants with cleft lip and palate. Infants are noncompliant toward producing specific facial expressions, and selecting the appropriate moment of acquisition is challenging. The objective was to estimate amount and spatial distribution of deformation of the face due to facial expression in infants with cleft lip and palate and provide recommendations for an improved acquisition protocol, including a method of quality control in terms of obtaining images with true neutral expression.

MATERIAL AND METHODS

Three-dimensional surface images of ten 4-month-old infants with unrepaired cleft lip and palate were obtained using a 3dMDface stereophotogrammetric system. For each subject, five surface images judged as representing a neutral expression were obtained during the same photo session. Mean and maximum deformations were calculated. A formalized review was performed, allowing the image exhibiting the "best" neutral expression to be selected, thus decreasing errors due to residual facial expression.

RESULTS

Deformation due to facial expression generally increased from forehead to chin. The amount of deformation in three selected regions were determined: nose (mean, 1 mm; maximum = 3 mm); cleft region (mean, 2 mm; maximum = 5 mm); chin region (mean, 5 mm; maximum = 12 mm). Analysis indicated that introduction of a formalized review of images could reduce these errors by a factor of 2.

CONCLUSIONS

The continuous change of facial expression in infants represents a substantial source of error; however, this may be reduced by incorporating a formalized review into the acquisition protocol.

Phenotype in 18 Danish subjects with genetically verified CHARGE syndrome

CHARGE (coloboma of the eye, heart defects, choanal atresia, retarded growth and development, genital hypoplasia and ear anomalies and/or hearing loss) syndrome is a rare genetic, multiple-malformation syndrome. About 80% of patients with a clinical diagnose, have a mutation or a deletion in the gene encoding chromodomain helicase DNA-binding protein 7 (CHD7). Genotype-phenotype correlation is only partly known. In this nationwide study, phenotypic characteristics of 18 Danish CHD7 mutation positive CHARGE individuals (N = 18) are presented. We studied patient records, clinical photographs, computed tomography, and magnetic resonance imaging (MRI). Information was not available for all traits in all subjects. Therefore, the results are presented as fractions. The following prevalence of cardinal symptoms were found: coloboma, 16/17; heart defects, 14/18; choanal atresia, 7/17; retarded growth and development, 11/13; genital abnormalities, 5/18; ear anomalies, 15/17 and sensorineural hearing loss, 14/15. Vestibular dysfunction (10/13) and swallowing problems (12/15) were other frequent cranial nerve dysfunctions. Three-dimensional reconstructions of MRI scans showed temporal bone abnormalities in >85%. CHARGE syndrome present a broad phenotypic spectrum, although some clinical features are more frequently occurring than others. Here, we suggest that genetic testing for CHD7 mutation should be considered in neonates with a specific combination of several clinical symptoms.

RUNX2 analysis of Danish cleidocranial dysplasia families

Cleidocranial dysplasia (CCD) is an autosomal dominant inherited disease caused by mutations in the Runt gene RUNX2. Screening of 19 Danish CCD families revealed 16 pathogenic mutations (84%) representing 8 missense mutations, 2 nonsense mutations, 4 frame-shift mutations and 2 large deletions in the RUNX2 locus. Eight mutations were novel, two were found twice, and polymorphisms were found in the promoter region and in the conserved polyglutamine/polyalanine repeat. A large duplication downstream of RUNX2 found in one patient suggests a possible regulatory RUNX2 element. The CCD phenotypes and genotypes adhere to the large phenotypic variability reported in previous CCD studies. Identification of large chromosome aberrations in or near the RUNX2 locus in 3 of the 19 cases suggests copy number analyses to be included in future RUNX2 mutation analyses.

A paediatric bone index derived by automated radiogrammetry

SUMMARY

Hand radiographs are obtained routinely to determine bone age of children. This paper presents a method that determines a Paediatric Bone Index automatically from such radiographs. The Paediatric Bone Index is designed to have minimal relative standard deviation (7.5%), and the precision is determined to be 1.42%.

INTRODUCTION

We present a computerised method to determine bone mass of children based on hand radiographs, including a reference database for normal Caucasian children.

METHODS

Normal Danish subjects (1,867), of ages 7-17, and 531 normal Dutch subjects of ages 5-19 were included. Historically, three different indices of bone mass have been used in radiogrammetry all based on A = piTW(1 - T/W), where T is the cortical thickness and W the bone width. The indices are the metacarpal index A/W(2), DXR-BMD = A/W, and Exton-Smith's index A/(WL), where L is the length of the bone. These indices are compared with new indices of the form A/(W(a) L(b)), and it is argued that the preferred index has minimal SD relative to the mean value at each bone age and sex. Finally, longitudinal series of X-rays of 20 Japanese children are used to derive the precision of the measurements.

RESULTS

The preferred index is A/(W(1.33) L(0.33)), which is named the Paediatric Bone Index, PBI. It has mean relative SD 7.5% and precision 1.42%.

CONCLUSIONS

As part of the BoneXpert method for automated bone age determination, our method facilitates retrospective research studies involving validation of the proposed index against fracture incidence and adult bone mineral density.

X-linked hypohidrotic ectodermal dysplasia. Genetic and dental findings in 67 Danish patients from 19 families

This study aimed to investigate genotype and phenotype in males affected with X-linked hypohidrotic ectodermal dysplasia (HED) and in female carriers, to analyse a possible genotype-phenotype correlation, and to analyse a possible relation between severity of the symptoms and the X-chromosome inactivation pattern in female carriers. The study group comprised 67 patients from 19 families (24 affected males and 43 female carriers). All participants had clinical signs of ectodermal dysplasia and a disease-causing EDA mutation. The EDA gene was screened for mutations by single-stranded conformational polymorphism and direct sequencing. Multiplex ligation-dependent probe amplification (MLPA) analysis was used to detect deletions/duplications in female probands. Sixteen different EDA mutations were detected in the 19 families, nine not described previously. The MLPA analysis detected a deletion of exon 1 in one female proband. No genotype-phenotype correlations were observed, and female carriers did not exhibit a skewed X-chromosome inactivation pattern. However, in two female carriers with pronounced clinical symptoms, in whom the parental origin of each allele was known, we observed that mainly the normal allele was inactivated.

Influence of mouthguard on temporomandibular joint

The aim of this study is to examine whether wearing a mouthguard (MG) has an influence on temporomandibular joint (TMJ) components (i.e., the condyle and the articular disk) and whether clenching with a resilient MG has an effect on the same components. Twenty-six healthy volunteers (15 females, 11 males) with an age range of 26-42 years old (median 28 years) participated in this study. Among all 52 joints in the 26 subjects, anterior disk displacement (AntDD) was recognized in 15. Thus, we classified the 52 joints into two groups, the AntDD group and the Normal group. Resilient thermoplastic materials were used to fabricate two types of MG, one that raised the vertical dimension height by 3 mm and another that raised it by 6 mm. Subjects were scanned with/without two types of MG with/without clenching by magnetic resonance imaging (MRI). The movement of the condylar head and articular disk was measured in the magnetic resonance images using the special subtraction technique. Wearing the MG without clenching did not have a negative influence on the TMJ and clenching in the Normal group. In the AntDD group, however, the relationship between the disk and condyle was affected by clenching and the degree of disk displacement was worsened by clenching with the thicker MG. From our results, we recommend that athletes with an internal derangement of the TMJ not wear the thicker MG and attention should be paid to its setting. And the subtraction technique using MRI was thought as a good tool for detecting a slight change in the TMJ.

Anthropometric and cephalometric measurements in X-linked hypohidrotic ectodermal dysplasia

OBJECTIVE

To describe the somatic development and craniofacial morphology in males affected with hypohidrotic ectodermal dysplasia (HED) and female carriers and to find clinical markers for early clinical diagnosis of possible female carriers.

DESIGN

A clinical and radiographic examination of the affected males and the female carriers.

SETTING AND SAMPLE POPULATION

Twenty-four affected males and 43 female carriers with a known mutation in the ED1 gene were examined in a dental clinic in either Copenhagen or Aarhus, Denmark.

EXPERIMENTAL VARIABLES

Height, body mass index (BMI) and head circumference. Cephalometric analysis of the craniofacial morphology.

OUTCOME MEASURE

Data on the somatic and craniofacial development in the affected males and female carriers.

RESULTS

No difference was observed regarding body height in the affected males and female carriers, BMI values were lower than the mean in most affected boys and adolescence and head circumference was somewhat decreased in both groups compared to normative data. The cephalometric analysis showed a reduced maxilla length and prognathism, a normal size and shape of the mandible and a reduced sagittal jaw relationship in both HED groups. Furthermore, affected males had a retroclined nasal bone and a more anteriorly inclined maxilla. A short nose, protruding lips, reduced facial convexity and facial height, characterized the soft tissue profile of the affected males. In female carriers, the lips were significantly retruded when compared with controls.

CONCLUSION

No specific somatic or cephalometric markers could be observed, in the female carrier group.

Three-dimensional analysis of mandibular growth and tooth eruption

Normal and abnormal jaw growth and tooth eruption are topics of great importance for several dental and medical disciplines. Thus far, clinical studies on these topics have used two-dimensional (2D) radiographic techniques. The purpose of the present study was to analyse normal mandibular growth and tooth eruption in three dimensions based on computer tomography (CT) scans, extending the principles of mandibular growth analysis proposed by Björk in 1969 from two to three dimensions. As longitudinal CT data from normal children are not available (for ethical reasons), CT data from children with Apert syndrome were employed, because it has been shown that the mandible in Apert syndrome is unaffected by the malformation, and these children often have several craniofacial CT scans performed during childhood for planning of cranial and midface surgery and for follow-up after surgery. A total of 49 datasets from ten children with Apert syndrome were available for study. The number of datasets from each individual ranged from three to seven. The first CT scan in each of the ten series was carried out before 1 year of age, and the ages for the 49 scans ranged from 1 week to 14.5 years. The mandible and the teeth were segmented and iso-surfaces generated. Landmarks were placed on the surface of the mandible, along the mandibular canals, the inner contour of the cortical plate at the lower border of the symphysis menti, and on the teeth. Superimposition of the mandibles in the longitudinal series was performed using the symphysis menti and the mandibular canals as suggested by Björk. The study supported the findings of stability of the symphysis menti and the mandibular canals as seen in profile view previously reported by Björk & Skieller in 1983. However, the mandibular canals were, actually, relocated laterally during growth. Furthermore, the position of tooth buds remained relatively stable inside the jaw until root formation started. Eruption paths of canines and premolars were vertical, whereas molars erupted in a lingual direction. The 3D method would seem to offer new insight into jaw growth and tooth eruption, but further studies are needed.

Delineation of an interstitial 9q22 deletion in basal cell nevus syndrome

Basal cell nevus syndrome (Gorlin syndrome) is an autosomal dominant disorder characterized by the presence of multiple basal cell carcinomas (BCC), odontogenic keratocysts, palmoplantar pits, and calcification in the falx cerebri caused by mutational inactivation of the PTCH gene. In few cases, the syndrome is due to a microdeletion at 9q22. Using high-resolution chromosome analysis we have identified a patient with the karyotype, 46,XY,del(9)(q21.3q31) de novo. He had typical clinical features consistent with basal cell nevus syndrome, but also additional features likely to be caused by loss of additional chromosomal material in this region. The deletion breakpoints were characterized with fluorescence in situ hybridization (FISH) analysis using BAC clones. The 15 Mb long deletion includes 87 RefSeq genes including PTCH. Hemizygosity of one or more genes might contribute to the additional symptoms observed in this patient.

Craniofacial morphology and growth comparisons in children with Robin Sequence, isolated cleft palate, and unilateral complete cleft lip and palate

OBJECTIVE

Comparison of early craniofacial morphology and growth in children with nonsyndromic Robin Sequence (RS), isolated cleft palate (ICP), and unilateral complete cleft lip and palate (UCCLP).

SUBJECTS

One hundred eight children with cleft: 7 with RS, 53 with ICP, and 48 with UCCLP were included in the study. The children were drawn from the group of all Danish children with cleft born 1976 through 1981.

METHOD

Three-projection infant cephalometry.

RESULTS

The craniofacial morphology in the RS, ICP, and UCCLP groups had some common characteristics: a wide maxilla with decreased length and posterior height, wide nasal cavity, short mandible, bimaxillary retrognathia, and reduced pharyngeal airway. The shortest mandible was found in RS followed by ICP and UCCLP; the pharyngeal airway was reduced in RS and ICP, compared with UCCLP; and the maxillary complex and nasal cavity were wider in UCCLP than in the other groups. The amount of facial growth in all three groups was similar; however, the direction was more vertical in UCCLP than in RS and ICP.

CONCLUSION

Except for a shorter RS mandible, the facial morphology of infants with RS and ICP was similar, as was the amount of facial growth and the growth pattern. The differences in facial morphology can be ascribed to the difference in the primary anomaly. The amount of facial growth was similar in the three groups; however, the growth pattern showed a more vertical direction in UCCLP than in RS and ICP. It is hypothesized that the mandibular retrognathia in RS represents the outer end of that of the ICP distribution.

Early craniofacial morphology and growth in children with nonsyndromic Robin Sequence

PURPOSE

Craniofacial morphology and growth comparisons in children with untreated nonsyndromic Robin Sequence (RS) and a control group with unilateral incomplete cleft lip (UICL) in which the lip was surgically closed at 2 months of age.

MATERIAL

The 52 children (7 RS and 45 UICL) included in the study were drawn from a group representing all Danish cleft children born 1976 through 1981. The ages of the children were 2 and 22 months at the time of examination 1 and 2, respectively.

METHOD

The method of investigation was three-projection cephalometry. Craniofacial morphology was analyzed by means of linear, angular, and area variables. Growth at a specific anatomical location in a patient was defined as the displacement vector from the coordinate of the corresponding landmark at examination 1 to its coordinate at examination 2.

RESULTS

The most striking findings in the RS group were markedly increased posterior maxillary width, increased width of the nasal cavity, short maxilla with reduced posterior height, short mandible, bimaxillary retrognathia, and severe reduction in size of the pharyngeal airway. The amount of facial growth was similar in the two groups; however, a tendency toward a more vertical growth direction was observed in the RS group.

CONCLUSION

Facial morphology in children with RS differed significantly from that of children with UICL at both 2 and 22 months of age. The magnitude of facial growth was similar in the two groups, whereas a tendency toward a more vertical facial growth direction was observed in the RS group.

Human masticatory muscle volume and zygomatico-mandibular form in adults with mandibular prognathism

Although several investigators have reported associations between masticatory muscles and skeletal craniofacial form, there is no agreement on the association. We tested the hypothesis that masticatory muscle volume correlates with the size and form of the adjacent local skeletal sites. For this purpose, we investigated the morphological association of the cross-sectional area and volume of temporal and masseter muscles with zygomatico-mandibular skeletal structures using computerized tomography (CT) in 25 male adults with mandibular prognathism. Muscle variables significantly correlated with widths of the bizygomatic arch and temporal fossa but not with the cranium width. Masseter volume significantly correlated with cross-sectional areas of the zygomatic arch and mandibular ramus. Masseter orientation was almost perpendicular to the zygomatic arch and mandibular antegonial region. The zygomatic arch angle significantly correlated with the antegonial angle. The results of the study suggest that the masticatory muscles exert influence on the adjacent local skeletal sites.

Early craniofacial morphology and growth in children with unoperated isolated cleft palate

OBJECTIVE

Analysis of craniofacial morphology and growth in children with untreated isolated cleft palate (ICP) (cleft of the secondary palate only) at 2 and 22 months of age and comparison of the morphology and growth to that of a control group with unilateral incomplete cleft lip (UICL).

MATERIAL AND METHODS

A total of 98 cleft children (53 with ICP and 45 with UICL) drawn from a larger group representing all Danish children with cleft born in the period 1976 to 1981 were included in the study. Craniofacial morphology and growth were analyzed using three-projection infant cephalometry.

RESULTS

The ICP group differed significantly from the UICL group. The most striking findings in the ICP group were: short maxilla; reduced posterior maxillary height; increased posterior maxillary width (in the 2-month-old); short mandible; reduced posterior height of the mandible; bimaxillary retrognathia; and reduced pharyngeal depth, height, and area. The facial growth pattern was fairly similar in the two groups except for a somewhat more vertical growth direction in the ICP group.

CONCLUSION

The facial morphology in ICP children differs significantly from that of children with UICL of the same age. The differences in facial morphology can be ascribed to the difference in the primary anomaly in the ICP group. The facial growth pattern was fairly similar in the ICP and UICL group; however, a somewhat more vertical growth direction was observed in the ICP group.

A three-dimensional method of visualizing the temporomandibular joint based on magnetic resonance imaging in a case of juvenile chronic arthritis

AIM

The purpose of this study was to present a new visualizing method for temporomandibular joint (TMJ) pathology in 3D at several condylar positions and to apply the method to a case of juvenile chronic arthritis (JCA) with previously diagnosed bilateral TMJ disorder and to a subject without signs and symptoms from the TMJ.

SUBJECT

The 20-year-old female patient had suffered from polyarticular JCA from the age of 6 years 8 months. The present study is based on a follow-up examination after the completion of orthodontic treatment with the Herbst appliance. Both TMJs were examined using magnetic resonance imaging (MRI) at closed and open mouth positions. The mandibular condyle, the glenoid fossa and the articular disc were segmented and 3D reconstruction of these structures was carried out.

RESULTS

The condyle was characterized by an increased sagittal diameter with osteophyte-like formation at the anterior aspect of the condylar head and flattening of the superior surface. The depth of the glenoid fossa was reduced and the articular eminence was remarkably flat. The articular disc was markedly diminished and posteriorly placed on the condylar head. The distance of the condylar path during mouth opening was reduced and the curvature of the condylar path was quite flat. The disc moved slightly posteriorly on the condylar head and remained in the glenoid fossa during mouth opening.

CONCLUSION

The imaging modality described improves visualization of TMJ morphology and gains insight into the TMJ pathology of the JCA patient, adding to understanding of the clinical problems.

Orofacial pain, jaw function, and temporomandibular disorders in women with a history of juvenile chronic arthritis or persistent juvenile chronic arthritis

OBJECTIVES

We sought to study the long-term outcome of juvenile chronic arthritis (JCA) in the temporomandibular joint (TMJ).

STUDY DESIGN

Temporomandibular disorders, including TMJ involvement, were assessed in 42 women with pauciarticular or polyarticular JCA--on average 25.8 years from disease onset--and compared with those found in matched control subjects. Disease-related parameters associated with temporomandibular disorders were identified.

RESULTS

The TMJ was involved in 66.7% of the patients, most severely in extended pauciarticular JCA. Temporomandibular disorders were more frequent in the patients than in the control subjects, especially in those with persistent disease. The TMJ involvement was positively correlated with disease duration and negatively correlated with jaw opening and occlusal support. Duration of active JCA and history of functional pain were identified as predictors of present TMJ involvement.

CONCLUSION

In a long-term follow-up, TMJ involvement proved frequent in the studied patients and was associated with long disease duration and previous pain on jaw opening. The findings suggest that patients with JCA should undergo orofacial evaluation on a regular basis.

A method for three-projection infant cephalometry

OBJECTIVE

To assess morphology and growth in infants and children with craniofacial anomalies based on comprehensive digitization of radiographic films in three, mutually orthogonal projections.

METHOD

The method consists of (1) acquisition of radiographic films in a highly standardized three-projection (lateral, frontal, and axial) cephalometer, (2) marking and digitization of a total of 279 anatomical landmarks in the three projections, and (3) computation and presentation (tabular and graphical) of 356 linear and angular variables describing the craniofacial morphology, including soft tissue. Computation of statistical entities describing a patient, a group of patients, the differences between patients or groups of patients was carried out. Error assessment of the method involved investigation of error distribution among a number of error sources. Duplicate digitization of radiographic films from 30 randomly selected patients, and from 10 dry skulls, was carried out to determine the errors contributed by the procedure of landmark digitization and the distribution of error among landmarks and variables, as well as between projections.

RESULTS

The average error due to landmark digitization, s(i), determined by duplicate digitization and calculated by use of Dahlberg's formula was 0.8 mm for linear variables and 1.6 degrees for angular variables.

CONCLUSION

This method of infant cephalometry has been shown to be highly accurate and reproducible, and it adds significant new potential for, e.g., asymmetry detection, population comparison, and growth measurements compared to other cephalometric techniques due to its standardized acquisition and digitization protocol, inclusion of an axial projection, and the large number of well-defined landmarks and variables involved.

Mutations in the gene encoding c-Abl-binding protein SH3BP2 cause cherubism

Cherubism (MIM 118400) is an autosomal dominant inherited syndrome characterized by excessive bone degradation of the upper and lower jaws followed by development of fibrous tissue masses, which causes a characteristic facial swelling. Here we describe seven mutations in the SH3-binding protein SH3BP2 (MIM 602104) on chromosome 4p16.3 that cause cherubism.

Surface-bounded growth modeling applied to human mandibles

From a set of longitudinal three-dimensional scans of the same anatomical structure, we have accurately modeled the temporal shape and size changes using a linear shape model. On a total of 31 computed tomography scans of the mandible from six patients, 14,851 semilandmarks are found automatically using shape features and a new algorithm called geometry-constrained diffusion. The semilandmarks are mapped into Procrustes space. Principal component analysis extracts a one-dimensional subspace, which is used to construct a linear growth model. The worst case mean modeling error in a cross validation study is 3.7 mm.

Quantification of osseous facial dysmorphology in untreated unilateral coronal synostosis

Unilateral coronal synostosis results in dysmorphology of the midface in addition to well-characterized cranial and orbital deformities. Because most American infants with this problem have undergone cranio-orbital surgery within their first year of life for the past 25 years, a paucity of data exist regarding the natural history of untreated unilateral coronal synostosis. In an attempt to remedy this void, an international search was conducted to identify computed tomography data sets of living individuals with untreated unilateral coronal synostosis; data were obtained from two European centers and one center in the United States. Results limited to the study of the midface are presented here. Digital data from high-resolution head computed tomography scans of 11 living, white individuals with untreated unilateral coronal synostosis were obtained from three craniofacial centers (in Denmark, The Netherlands, and the United States). Image volumes were constructed from each scan using ANALYZE biomedical imaging software. Fourteen pairs of three-dimensional distances were calculated on the ipsilateral (the side of the synostosis) and the contralateral (the side opposite to the synostosis) hemifaces using 11 osseous landmarks. The resulting measurements were expressed as a ratio of the ipsilateral: contralateral sides. Descriptive statistics were derived for the untreated unilateral coronal synostosis population and compared with analogous measurements performed on dried skulls. Age at computed tomography ranged from 1.1 to 21.1 years (mean, 6.6 years; median, 4.1 years). Twelve of the 14 measured distances differed by greater than 5 percent on the ipsilateral side, and all but one of these measurements were decreased on the ipsilateral side when compared with contralateral values. The results of this study support the following conclusions: (1) There are discrete and measurable differences in the facial morphology between patients with untreated unilateral coronal synostosis and normal skulls. (2) Intercenter and international collaboration can provide a sufficient number of individuals with rare craniofacial anomalies to quantitatively determine group characteristics. (3) Quantitative documentation of rare anomaly natural history is necessary for quantitative outcome assessment of treated patients.

Craniofacial comparisons in 22-month-old lip-operated children with unilateral complete cleft lip and palate and unilateral incomplete cleft lip

OBJECTIVE

The objective of the study was to analyze the craniofacial morphology in infants with unilateral complete cleft lip and palate (UCCLP) in which the lip and the anterior part of the palate had been surgically closed at 2 months of age and to compare the morphology with that of a control group with unilateral incomplete cleft lip (UICL) in which the lip had also been surgically closed at 2 months of age.

DESIGN

The sample consisted of a total of 108 cleft children all fulfilling the entry criteria, besides diagnosis, as follows: The child was of Danish origin; the age of the child was between 650 and 750 days (approximately 22 months) at the time of examination; the child was healthy except for its single cleft malformation; the surgical procedure in each group had been performed at about 2 months of age by the same surgeon. The surgical methods used were a Tennison procedure (UICL group) and a Tennison procedure supplemented by palatovomer plasty (UCCLP group).

METHODS

The method of investigation was infant cephalometry in the lateral, frontal, and axial projections. Linear, angular, and area variables describing the craniofacial morphology were calculated and supplemented by mean plots from the cephalometric projections in the two groups.

RESULTS AND CONCLUSIONS

Statistical analysis based on Student's t test showed that the facial morphology in the 22-month-old UCCLP group differed significantly from that of the UICL group. The most pronounced differences were found in the maxillary complex and the mandible. The deviations observed in the UCCLP group at 22 months of age were similar to those previously observed at 2 months of age. However, several of the dysmorphic traits had become less pronounced; some had remained the same; and a few had become worse with time.

Oral manifestations of Schimmelpenning syndrome: case report and review of literature

Schimmelpenning syndrome (SS) is characterised by specific skin manifestations, skeletal defects, and central nervous system abnormalities. Here, the SS is briefly reviewed, and the oral and dental manifestations are described in a patient whose medical findings were previously published and included severe hypophosphatemic rickets. Significant oral and dental features included papillomatous lesions of the gingiva, hemihyperplasia (hemihypertrophy) of the tongue, bone cysts, aplasia of teeth, enlarged pulp chambers, hypoplastic or absent enamel, and an odontodysplasia-like permanent tooth.

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.

Drying and rewetting anterior crown fragments prior to bonding

Fractured anterior teeth can be restored by adhesive bonding of the fragment to the remaining tooth structure. This in vitro study describes the effect on fracture strength of fragments dried and rewetted for various periods of time prior to bonding. Seventy central incisors from sheep were fractured. The resulting incisal crown fragments were then stored in air at room temperature at ambient humidity (70 +/- 16%) for 5 s, 30 min, 1 h, 3 h, 6 h, 12 h, or 24 h. The apical parts of the fractured teeth were stored in water. After storage in air each fragment was then bonded to the matching apical tooth structure with a bonding agent and a low-viscosity composite resin. After water storage for 2 days, mean fracture strength was measured. Another group of teeth comprising 40 sheep central incisors was fractured and the fragments were stored in air at room temperature for 24 h as above. The fragments were then immersed in water for 10 min, 1 h, 1 day, or 7 days, prior to bonding and measurement as described above. Statistical analysis revealed that the fracture strength of the fragment-bonded teeth was unaffected by air storage of the fragment for up to 1 h prior to bonding, after which additional drying resulted in decreased fracture strength. Fragments dried for 24 h in air and rewetted by immersion in water for at least 1 day were fragment-bonded without loss of fracture strength.

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.

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.

Cephalometric study of the Apert syndrome in adolescence and adulthood

This paper reports a cephalometric analysis of the craniofacial morphology in adolescents and adults with Apert syndrome. The sample comprised 26 patients with Apert syndrome (15 males and 11 females). The control group consisted of 153 adults (102 males and 51 females). Both lateral and frontal cephalograms were studied. The data were presented as mean plots of the craniofacial region together with data on some of the most significant findings. Marked differences were found in nearly all craniofacial regions except the mandible. The calvaria was increased in height and width but length was decreased. The cranial base showed marked protrusion of the greater wing of the sphenoid, which contributed to severe reduction of orbital volume and protrusion of the eyeglobe. Orbital volume was further reduced by maxillary hypoplasia in all three planes of space together with retrognathia. Maxillary height was extremely short and so was the nose. The width of the nasal cavity, height and depth of the bony nasopharynx, and the nasopharyngeal airway were all markedly reduced in size. The mandible was of fairly normal size and shape but was posteriorly inclined. Head posture was extended in relation to the cervical column. Total facial height was increased, whereas upper facial height was markedly reduced. Incisor occlusion showed mandibular overjet and open bite. Apert syndrome patients were then compared to a group of Crouzon syndrome patients. Marked and significant differences were found between the two syndromes in nearly all craniofacial regions, and craniofacial dysmorphology was generally more severe in Apert syndrome patients.

External and internal macromorphology in 3D-reconstructed maxillary molars using computerized X-ray microtomography

AIM

The aim of this study was to perform a qualitative analysis of the relationship between the external and internal macromorphology of the root complex and to use fractal dimension analysis to determine the correlation between the shape of the outer surface of the root and the shape of the root canal.

METHODOLOGY

On the basis of X-ray computed transaxial microtomography, a qualitative and quantitative analysis of the external and internal macromorphology of the root complex in permanent maxillary molars was performed using well-defined macromorphological variables and fractal dimension analysis. Five maxillary molars were placed between a microfocus X-ray tube with a focal spot size of 0.07 mm, a Thomson-SCF image intensifier, and a CCD camera compromising a detector for the tomograph. Between 100 and 240 tomographic 2D slices were made of each tooth. Assembling slices for 3D volume was carried out with subsequent median noise filtering. Segmentation into enamel, dentine and pulp space was achieved through thresholding followed by morphological filtering. Surface representations were then constructed. A useful visualization of the tooth was created by making the dental hard tissues transparent and the pulp chamber and root-canal system opaque. On this basis it became possible to assess the relationship between the external and internal macromorphology of the crown and root complex.

RESULTS

There was strong agreement between the number, position and cross-section of the root canals and the number, position and degree of manifestation of the root complex macrostructures. Data from a fractal dimension analysis also showed a high correlation between the shape of the root canals and the corresponding roots.

CONCLUSIONS

It is suggested that these types of 3D volumes constitute a platform for preclinical training in fundamental endodontic procedures.

Perspectives on craniofacial syndromes

This article reviews syndrome classification; types of anomalies and their interrelations; syndrome delineation; birth prevalence; nomenclature; molecular delineation; and phenotype/genotype correlations.

Is craniofacial morphology in Apert and Crouzon syndromes the same?

This article reviews previous research on the craniofacial development in Apert and Crouzon syndromes and adds new roentgencephalometric information. It is concluded that craniofacial development in the two syndromes is not the same. Marked differences were found in the calvaria, cranial base, orbit, maxilla, zygoma, incisal occlusion, and soft tissue profile. In general, abnormal craniofacial morphology was more severe in Apert syndrome than in Crouzon syndrome.

Adhesive bonding of fractured anterior teeth: effect of wet technique and rewetting agent

PURPOSE

To compare the fracture strength of intact teeth with that of fractured crowns bonded with adhesive and a resin material on either wet or dry dentin, or dried dentin rewetted with a rewetting agent for various periods of time.

MATERIALS AND METHODS

Sheep central incisors were divided into seven groups, each of 10 teeth. Group 1: Intact teeth tested for fracture strength in an Instron testing machine and used as controls. Groups 2-7 were sectioned in a vice equipped with sharp blades, 2.5 mm away from and parallel to the incisal edge. The two fracture surfaces were etched with 37% phosphoric acid for 15 s and rinsed with water for 5-6 s. Group 2: The surfaces were air-dried for 2 s. Group 3: As for Group 2 but the surfaces were rewetted with Aqua-Prep for 2 s and immediately air-blasted to remove excess. Group 4: As for Group 3, but the rewetting agent was applied for 10 s before air-blasting. Group 5: As for Group 4, but the rewetting agent was applied for 20 s. Group 6: As for Group 4, but the rewetting agent was applied for 30 s. Group 7: As for Group 2, but the surfaces were left moist after etching and rinsing by gently shaking the specimens twice. The fracture surfaces of Groups 2-7 were rebonded with All-Bond 2 adhesive system and Aeliteflo composite. After 48 hrs the restored teeth were debonded in the Instron testing machine. Fracture strengths were calculated and compared with the fracture strength of intact teeth (control group).

RESULTS

Newman-Keuls' multiple range test revealed that there was a statistically significant difference between the control mean and the means of Groups 2 and 3. All other means were not significantly different. Drying of the dentin surface decreased the bonding strength, and rewetting of the dried dentin for 2 s was not sufficient to rewet the collapsed collagen fibers, as indicated by a decrease of fracture strength.

Adhesive bonding of fragmented anterior teeth

This in vitro study investigated the fracture strengths of fractured incisors after reattachment to the remaining tooth structure, using either Gluma dentin-bonding agent together with 1 of 13 different experimental resins or 1 of the following dentin-bonding agents: Gluma+ (experimental modification of Gluma), Panavia21, ScotchBond1 (SingleBond), All-Bond2, Dentastic, SuperBond, Prime&Bond 2.1. No significant differences were found in the experiments with various experimental resins. The fracture strength of teeth rebonded with Gluma, All-Bond2, Dentastic, SuperBond or Prime&Bond 2.1 showed mean fracture strengths in the range of 8.7-11.2 MPa, which were significantly different in all cases from that of intact teeth (16.3 MPa). Teeth bonded with Gluma+, Panavia21 or ScotchBond1 (SingleBond) showed mean fracture strengths of 15.5, 14.6, and 14.2 MPa, respectively. These fracture strengths were not significantly different from that of intact teeth.

The Ekman-Westborg-Julin syndrome: report of case

The Ekman-Westborg-Julin Syndrome is reveiwed and a new case reported.

The role of bone centers in the pathogenesis of craniosynostosis: an embryologic approach using CT measurements in isolated craniosynostosis and Apert and Crouzon syndromes

This paper describes the role of the displacement of bone centers, i.e., the tubers, in the pathogenesis of craniosynostosis. This displacement was studied in 54 patients with isolated or syndromic craniosynostosis in the form of CT scans as well as in two dry neonate skulls with Apert syndrome. For comparison, 49 fetal and 8 normal infant dry skulls were studied. Our investigation was restricted to the coronal and metopic sutures. The results showed a significantly more occipital localization of the frontal bone center and a more frontal localization of the parietal bone center at the side of a synostotic coronal suture in the isolated form as well as in Apert syndrome. In contrast, this was not the case in Crouzon syndrome, thus showing that these two syndromes have a different pathogenesis. For trigonocephaly, a more anteromedial localization of the frontal bone centers was found.