Fine Breakpoint Mapping by Genome Sequencing Reveals the First Large X Inversion Disrupting the NHS Gene in a Patient with Syndromic Cataracts

Inversions are structural variants that are generally balanced. However, they could lead to gene disruptions or have positional effects leading to diseases. Mutations in the NHS gene cause Nance-Horan syndrome, an X-linked disorder characterised by congenital cataracts and dental anomalies. Here, we aimed to characterise a balanced pericentric inversion X(p22q27), maternally inherited, in a child with syndromic bilateral cataracts by breakpoint mapping using whole-genome sequencing (WGS). 30× Illumina paired-end WGS was performed in the proband, and breakpoints were confirmed by Sanger sequencing. EdU assays and FISH analysis were used to assess skewed X-inactivation patterns. RNA expression of involved genes in the breakpoint boundaries was evaluated by droplet-digital PCR. We defined the breakpoint position of the inversion at Xp22.13, with a 15 bp deletion, disrupting the unusually large intron 1 of the canonical NHS isoform, and also perturbing topologically-associated domains (TADs). Moreover, a microhomology region of 5 bp was found on both sides. RNA analysis confirmed null and reduced NHS expression in the proband and his unaffected mother, respectively. In conclusion, we report the first chromosomal inversion disrupting NHS, fine-mapped by WGS. Our data expand the clinical spectrum and the pathogenic mechanisms underlying the NHS defects.

Rare and de novo variants in 827 congenital diaphragmatic hernia probands implicate LONP1 as candidate risk gene

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly that is often accompanied by other anomalies. Although the role of genetics in the pathogenesis of CDH has been established, only a small number of disease-associated genes have been identified. To further investigate the genetics of CDH, we analyzed de novo coding variants in 827 proband-parent trios and confirmed an overall significant enrichment of damaging de novo variants, especially in constrained genes. We identified LONP1 (lon peptidase 1, mitochondrial) and ALYREF (Aly/REF export factor) as candidate CDH-associated genes on the basis of de novo variants at a false discovery rate below 0.05. We also performed ultra-rare variant association analyses in 748 affected individuals and 11,220 ancestry-matched population control individuals and identified LONP1 as a risk gene contributing to CDH through both de novo and ultra-rare inherited largely heterozygous variants clustered in the core of the domains and segregating with CDH in affected familial individuals. Approximately 3% of our CDH cohort who are heterozygous with ultra-rare predicted damaging variants in LONP1 have a range of clinical phenotypes, including other anomalies in some individuals and higher mortality and requirement for extracorporeal membrane oxygenation. Mice with lung epithelium-specific deletion of Lonp1 die immediately after birth, most likely because of the observed severe reduction of lung growth, a known contributor to the high mortality in humans. Our findings of both de novo and inherited rare variants in the same gene may have implications in the design and analysis for other genetic studies of congenital anomalies.

Two loss-of-function ANKRD11 variants in Chinese patients with short stature and a possible molecular pathway

KBG syndrome is a rare genetic disease characterized mainly by skeletal abnormalities, distinctive facial features, and intellectual disability. Heterozygous mutations in ANKRD11 gene, or deletion of 16q24.3 that includes ANKRD11 gene are the cause of KBG syndrome. We describe two patients presenting with short stature and partial facial features, whereas no intellectual disability or hearing loss was observed in them. Two ANKRD11 variants, c.4039_4041del (p. Lys1347del) and c.6427C > G (p. Leu2143Val), were identified in this study. Both of them were classified as variants of uncertain significance (VOUS) by ACMG/AMP guidelines and were inherited from their mothers. ANKRD11 could enhance the transactivation of p21 gene, which was identified to participate in chondrogenic differentiation. In this study, we demonstrated that the knockdown of ANKRD11 could reduce the p21-promoter luciferase activities while re-introduction of wild type ANKRD11, but not ANKRD11 variants (p. Lys1347del or p. Leu2143Val), could restore the p21 levels. Thus, our study report two loss-of-function ANKRD11 variants which might provide new insight on pathogenic mechanism that correlates ANKRD11 variants with the short stature phenotype of KBG syndrome.

Effects of Reduced Connexin43 Function on Mandibular Morphology and Osteogenesis in Mutant Mouse Models of Oculodentodigital Dysplasia

Mutations in the gene encoding the gap-junctional protein connexin43 (Cx43) are the cause of the human disease oculodentodigital dysplasia (ODDD). The mandible is often affected in this disease, with clinical reports describing both mandibular overgrowth and conversely, retrognathia. These seemingly opposing observations underscore our relative lack of understanding of how ODDD affects mandibular morphology. Using two mutant mouse models that mimic the ODDD phenotype (I130T/+ and G60S/+), we sought to uncover how altered Cx43 function may affect mandibular development. Specifically, mandibles of newborn mice were imaged using micro-CT, to enable statistical comparisons of shape. Tissue-level comparisons of key regions of the mandible were conducted using histomorphology, and we quantified the mRNA expression of several cartilage and bone cell differentiation markers. Both G60S/+ and I130T/+ mutant mice had altered mandibular morphology compared to their wildtype counterparts, and the morphological effects were similarly localized for both mutants. Specifically, the biggest phenotypic differences in mutant mice were focused in regions exposed to mechanical forces, such as alveolar bone, muscular attachment sites, and articular surfaces. Histological analyses revealed differences in ossification of the intramembranous bone of the mandibles of both mutant mice compared to their wildtype littermates. However, chondrocyte organization within the secondary cartilages of the mandible was unaffected in the mutant mice. Overall, our results suggest that the morphological differences seen in G60S/+ and I130T/+ mouse mandibles are due to delayed ossification and suggest that mechanical forces may exacerbate the effects of ODDD on the skeleton.

Calmodulin Directly Interacts with the Cx43 Carboxyl-Terminus and Cytoplasmic Loop Containing Three ODDD-Linked Mutants (M147T, R148Q, and T154A) that Retain α-Helical Structure, but Exhibit Loss-of-Function and Cellular Trafficking Defects

The autosomal-dominant pleiotropic disorder called oculodentodigital dysplasia (ODDD) is caused by mutations in the gap junction protein Cx43. Of the 73 mutations identified to date, over one-third are localized in the cytoplasmic loop (Cx43CL) domain. Here, we determined the mechanism by which three ODDD mutations (M147T, R148Q, and T154A), all of which localize within the predicted 1-5-10 calmodulin-binding motif of the Cx43CL, manifest the disease. Nuclear magnetic resonance (NMR) and circular dichroism revealed that the three ODDD mutations had little-to-no effect on the ability of the Cx43CL to form α-helical structure as well as bind calmodulin. Combination of microscopy and a dye-transfer assay uncovered these mutations increased the intracellular level of Cx43 and those that trafficked to the plasma membrane did not form functional channels. NMR also identify that CaM can directly interact with the Cx43CT domain. The Cx43CT residues involved in the CaM interaction overlap with tyrosines phosphorylated by Pyk2 and Src. In vitro and in cyto data provide evidence that the importance of the CaM interaction with the Cx43CT may lie in restricting Pyk2 and Src phosphorylation, and their subsequent downstream effects.

Living naked: first case of lack of skin-related structures in an elasmobranch, the blackmouth catshark (Galeus melastomus)

As far as is known, in this paper the first case of lacking of skin-related structures (epidermis, stratum laxum, dermal denticles and teeth) in a free-swimming elasmobranch, the blackmouth catshark, Galeus melastomus, is reported. The individual was caught by trawl in Sardinian waters (central-western Mediterranean) in July 2019 at a depth of 500 m. Although this kind of morphological abnormality is potentially fatal, the observations suggested that the specimen was in good health and well developed.

Dental Manifestations of Ehlers-Danlos Syndromes: A Systematic Review

Ehlers-Danlos syndromes (EDS) are a group of inherited connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and variable tissue fragility. However, there are limited published data on the dental manifestations of EDS. This review systematically assessed the spectrum of published dental anomalies in various types of EDS. Twentyfour individual case reports/series and 3 longer case-control studies, reporting on a total of 84 individuals with a clinical diagnosis of EDS, were included in the data analysis. The main dental features listed in classical EDS were pulp calcification and localized root hypoplasia. Common dental abnormalities observed in vascular EDS were pulp shape modifications (52.2%), exceeding root length (34.8%), and molar root fusion (47.8%). Dentinogenesis imperfecta is a consistent finding in osteogenesis imperfecta/EDS overlap syndrome. Data on dental manifestations in other types of EDS are both rare and generally inconclusive.

Clinico-radiologic features of molar-incisor malformation in a case series of 38 patients: A retrospective observational study

Molar-incisor malformation (MIM) is a recently defined dental abnormality of molar root and incisors, and introduced as one of the causes of periapical and periodontal abscess. The purpose of this study was to investigate the clinical and radiological features of MIM, with special emphasis on various medical history. A total of 38 patients with MIM were included in this study. Radiographic features and clinical data, including medical history, chief complaint, associated complications, treatment, and prognosis, were retrospectively investigated. On radiographs, the affected molars showed short, slender, underdeveloped roots and constricted pulp chambers. All affected incisors and canines exhibited dilacerated short roots, wedge-shaped defect on the cervical part of the crown. Complications included periodontal bone loss (52.6%), endodontic lesion (50.0%), and endodontic-periodontal lesion (28.9%). The medical histories of the patients with MIM indicate that almost all (94.7%) were hospitalized due to problems during the neonatal period. MIM may cause various dental problems, such as periapical and periodontal abscess and early loss of the affected teeth. The early diagnosis of MIM on radiographs and appropriate treatment will contribute to a favorable prognosis, especially for young and adolescent patients.

Two novel GJA1 variants in oculodentodigital dysplasia

Background

Oculodentodigital dysplasia (ODDD) is a rare disorder with pleiotropic effects involving multiple body systems, caused by mutations in the gap junction protein alpha 1 (GJA1) gene. GJA1 gene encodes a polytopic connexin membrane protein, Cx43, that is a component of connexon membrane channels.

Methods

We describe two unrelated female probands referred for a genetic review in view of a dysmorphic clinical phenotype.

Results

Two novel missense mutations in GJA1 that substitute conserved amino acids in the first and second transmembrane domains (NM_000165.5: c.77T>C p.Leu26Pro and NM_000165.5:c.287T>G p.Val96Gly) were detected through targeted sequencing of GJA1. These variants were detected in the heterozygous state in the two Maltese probands and segregated with the disease phenotype.

Conclusion

This report further expands the mutational spectrum of ODDD.

KBG syndrome presenting with brachydactyly type E

We report the case of a young woman who presented at age 10 years with height on the tenth centile, brachydactyly type E and mild developmental delay. Biochemistry and hormonal profiles were normal. Differential diagnoses considered included Albright hereditary osteodystrophy without hormone resistance (a.k.a pseudopseudohypoparathyroidism), 2q37 microdeletion syndrome and acrodysostosis. She had a normal karyotype and normal FISH of 2q37. Whole genome sequencing (WGS) identified a mutation in the ANKRD11 gene associated with KBG syndrome. We review the clinical features of the genetic syndromes considered, and suggest KBG syndrome be considered in patients presenting with syndromic brachydactyly type E, especially if short stature and developmental delay are also present.

Five-year follow-up outcomes of comprehensive rehabilitation in Korean siblings with cerebral, ocular, dental, auricular, skeletal anomalies (CODAS) syndrome: A case report

RATIONALE

Cerebral, ocular, dental, auricular, skeletal anomalies (CODAS) syndrome is a very rare multisystem disorder, which shows malformations of the central nervous system, ears, eyes, teeth, and skeleton that was first reported in 1991. Only a few cases that sporadically occurred have been reported worldwide. The research investigating the pathogenesis and patterns of CODAS inheritance is still ongoing. There is no satisfactory treatment for this rare genetic disease yet. Due to the lack of curative medical treatment, rehabilitation could play a major role in treatment for genetic disease.

PATIENT CONCERNS

To our best knowledge, the 2 children described in this study are the only CODAS syndromes siblings reported in the world so far. These Korean siblings show highly distinctive features consisting of developmental delay, cataracts, vulnerability to tooth decay, epiphyseal dysplasia, and anomalous ears.

DIAGNOSES

CODAS syndrome.

INTERVENTIONS

Comprehensive long-term rehabilitation treatment during 5 years.

OUTCOMES

We report on the progress of the comprehensive long-term rehabilitation treatment at 5-year follow-up. Their fine motor and language skills development improved similarly to that of same-aged children. We observed the positive effect of rehabilitation on the quality of life.

LESSONS

The therapy of genetic disorders is challenging for pediatric neurologists and pediatric physiatrists. We suggest that rehabilitation is the best treatment currently available for this genetic disease that yields satisfactory therapeutic effect.

GJA1 Variants Cause Spastic Paraplegia Associated with Cerebral Hypomyelination

Oculodentodigital dysplasia is an autosomal dominant disorder due to GJA1 variants characterized by dysmorphic features. Neurologic symptoms have been described in some patients but without a clear neuroimaging pattern. To understand the pathophysiology underlying neurologic deficits in oculodentodigital dysplasia, we studied 8 consecutive patients presenting with hereditary spastic paraplegia due to GJA1 variants. Clinical disease severity was highly variable. Cerebral MR imaging revealed variable white matter abnormalities, consistent with a hypomyelination pattern, and bilateral hypointense signal of the basal ganglia on T2-weighted images and/or magnetic susceptibility sequences, as seen in neurodegeneration with brain iron accumulation diseases. Patients with the more prominent basal ganglia abnormalities were the most disabled ones. This study suggests that GJA1-related hereditary spastic paraplegia is a complex neurodegenerative disease affecting both the myelin and the basal ganglia. GJA1 variants should be considered in patients with hereditary spastic paraplegia presenting with brain hypomyelination, especially if associated with neurodegeneration and a brain iron accumulation pattern.

Cervical Enamel Projection - A Rare Case Report with its Management

A developmental anomaly like cervical enamel projection is a rare finding in the maxillary anterior region. Its ectopic presence attracts attention in literature. This type of anomaly is typically found in the furcation region of molars. The case report presented here deals with the ectopic presence of combined anomalous lesion and its management. A 18 year old male presented with pronounced bilobed cingulum extending as a cervical enamel projection on the maxillary right lateral incisor associated with pain, exudation and difficulty in mastication. Enameloplasty and regenerative procedure was performed. The possible etiology, its management and healing evaluated by CBCT are presented in this report. One year follow up showed satisfactory healing with no recurrence of abscess.

Hide and seek: Impacted maxillary and mandibular canines from the Roman period Croatia

OBJECTIVE

The aim of this paper was to analyse the dental remains of an adult male with three impacted canines from the Roman period cemetery in Osijek, Croatia.

MATERIALS

The dental remains of an adult male aged 35-45 years at the time of death were analysed.

METHODS

Macroscopic analysis of dental remains was accompanied by radiographic examination.

RESULTS

The individual also had additional dental pathologies (carious lesion, antemortem tooth loss). A total of 21 permanent teeth were present in maxillae and mandible. Eighteen of them were normal fully erupted dentition, while three were impacted: left maxillary canine and both mandibular canines. The left maxillary and mandibular canines were mesially inclined, and the right mandibular canine was relatively horizontally positioned.

CONCLUSION

A case of non-syndrome impaction in which the lack of eruptive force in combination with the unfavorable position of the tooth bud might have resulted in multiple impacted teeth is presented.

SIGNIFICANCE

Current clinical knowledge reports low frequency of this anomaly, with maxillary impaction occurring more often than mandibular. Furthermore, canine impaction is even more rarely reported in the archaeological material. The presented case is the only one from the archaeological setting with impaction present both in maxillae and mandible.

LIMITATIONS

In modern populations multiple impactions are often associated with various syndromes. Since the majority of syndromes affect soft tissue, their association with impaction cannot be confirmed in archaeological populations.

Oro-dental phenotype in patients with RUNX2 duplication

Runt-related transcription factor 2 (RUNX2) is well-known for its role in bone development and tooth morphogenesis. Most RUNX2 mutations described in the literature result in loss-of-function mutations of RUNX2 responsible for cleidocranial dysplasia, an autosomal dominant disorder. We describe here the oro-dental phenotype of four patients of a unique family with a 285 kb duplication including the entire sequence of RUNX2, likely responsible for three functional copies of the gene, leading to an increased RUNX2 dosage. Several dental anomalies of number (hypodontia or oligodontia), morphology (microdontia, radiculomegaly, taurodontism or dens invaginatus) and tooth position (rotation) were found in these patients.

4q25 microdeletion encompassing PITX2: A patient presenting with tetralogy of Fallot and dental anomalies without ocular features

Axenfeld-Rieger syndrome (ARS) is a heterogeneous clinical entity transmitted in an autosomal dominant manner. The main feature, Axenfeld-Rieger Anomaly (ARA), is a malformation of the anterior segment of the eye that can lead to glaucoma and impair vision. Extra-ocular defects have also been reported. Point mutations of FOXC1 and PITX2 are responsible for about 40% of the ARS cases. We describe the phenotype of a patient carrying a deletion encompassing the 4q25 locus containing PITX2 gene. This child presented with a congenital heart defect (Tetralogy of Fallot, TOF) and no signs of ARA. He is the first patient described with TOF and a complete deletion of PITX2 (arr[GRCh37]4q25(110843057-112077858)x1, involving PITX2, EGF, ELOVL6 and ENPEP) inherited from his ARS affected mother. In addition, to our knowledge, he is the first patient reported with no ocular phenotype associated with haploinsufficiency of PITX2. We compare the phenotype and genotype of this patient to those of five other patients carrying 4q25 deletions. Two of these patients were enrolled in the university hospital in Toulouse, while the other three were already documented in DECIPHER. This comparative study suggests both an incomplete penetrance of the ocular malformation pattern in patients carrying PITX2 deletions and a putative association between TOF and PITX2 haploinsufficiency.

Blepharo-Cheilo-Dontic (BCD) Syndrome: Case Report

Objective

To report a case of blepharo-cheilo-dontic (BCD) syndrome, to compare with the previous cases, and to discuss the possible treatment.

Patient

The patient was a 14-day-old boy born uneventfully on August 7, 2002. His scalp hair was sparse and curly. A tumor on the top of his head, which was thought to be a dermoid cyst, and a nevus on the back of his left hand were observed. All typical symptoms of blepharo-cheilo-dontic syndrome, such as euryblepharon with ectropion of the lower eyelids, distichiasis, bilateral cleft lip and palate, severe oligodontia, and conical teeth, were observed. Because there was no fatal complication, and growth and development were about normal, it was recommended that a long and active treatment plan be considered for this patient.

Dental anomalies in different growth and skeletal malocclusion patterns

OBJECTIVES

To evaluate prevalence, distribution, and sexual dimorphism of dental anomalies (DA) among different skeletal malocclusions (SM) and growth patterns (GP) under the hypothesis that specific clinical patterns exist and may indicate common etiological roots.

MATERIALS AND METHODS

A total of 1047 orthodontic records of patients older than 8 years were evaluated. The SN-GoGn angle was used to classify GP (hypodivergent, normal, and hyperdivergent), and the ANB angle was used to verify SM (Angle Classes I, II, and III). These assessments were done from lateral cephalometric radiographs. DA were diagnosed using panoramic radiographs by one calibrated investigator. Odds ratios, chi-square, and Student's t-tests were used.

RESULTS

Of the subjects, 56.7% were female, with mean age of 16.41 (±10.61) years. The prevalence of DA was 15.7%. Impaction and tooth agenesis were the most prevalent DA, with relative frequencies of 14.4% and 9.7%, respectively. DA were most prevalent in Class III SM (80.8%) and in hypodivergent GP (82.5%), although this was not statistically significant. Tooth agenesis ( P < .01) and microdontia ( P = .025) were significantly more common among hypodivergent GP and Class III SM, respectively.

CONCLUSIONS

The results of this study support the idea that DA are preferentially associated with certain patterns of malocclusion.

Skeletal and dental effects on rats following in utero/lactational exposure to the non-dioxin-like polychlorinated biphenyl PCB 180

Polychlorinated biphenyls (PCBs) are a large class of persistent organic pollutants that are potentially harmful to human and wildlife health. Although a small number of dioxin-like (DL) PCBs are well characterized, the majority of PCBs have non-dioxin-like (NDL) modes of action and biological effects that are less understood. We conducted a dose-response study of the skeletal and dental effects of in utero/lactational exposure to 2,2',3,4,4',5,5'-heptachlorobiphenyl (PCB 180), a NDL PCB congener that is abundantly present in the environment and foods, including mother’s milk. In a sample of 35- and 84-day-old male and female offspring from pregnant rats exposed to different doses of PCB 180 (0, 10, 30, 100, 300, and 1000 mg/kg bw), we measured the three-dimensional (3D) coordinates of 27 landmarks on the craniofacial skeleton with a Microscribe G2X system, the buccolingual width of all molars with digital sliding calipers, and a variety of tibial parameters with peripheral quantitative computed tomography (pQCT) and a biomechanical testing apparatus. The landmark coordinates were analyzed for variation in size, shape, and fluctuating asymmetry (FA) using MorphoJ software, showing no effects on cranial size, on FA in females only (i.e., decreased asymmetry), and on shape in both sexes (i.e., decreased facial length and shift in the palatal suture). In the maxillary teeth, females in the highest dose group showed a significant decrease of 0.1 mm (p = 0.033) of the second molar only, whereas males in most dose groups showed average increases of 0.1 mm (p = 0.006–0.044) in all three molars. In the mandibular teeth, the only significant response to PCB 180 exposure was the average increase of 0.1 mm (p = 0.001–0.025) in the third molars of males only. Males also shower greater sensitivity in postcranial effects of increased tibial length and decreased cortical bone mass density, although only females showed significant effects on tibial bone area and thickness. These results demonstrate marked sex differences in effects of PCB 180, which can be attributed to differences in their underlying biological mechanisms of toxicity. Furthermore, although tooth and bone development are targets of both DL and NDL compounds, this study shows that there are marked differences in their mechanisms and effects.

Interference factors regarding the path of insertion of rotational-path removable partial dentures

BACKGROUND

The aims of this study were to evaluate the effect of the location of the rotational center and the morphology of teeth resulting in interference with the rotational path of insertion and to estimate when an interference test should be performed.

METHODS

A total of 400 dental radiograms of maxillary and mandibular first and second molars (100 for each position) were selected. The radiograms were used to hand-sketch the outlines on tracing paper. Then, an interference test was simulated using calipers. Mesial long occlusal rest seats with three different lengths were designed. A curve-simulated rotational path was drawn on the tracing paper showing the outline of a molar. If the curve was intersected by the mesial outline, interference was occurred. A total of 1200 tests were performed.

RESULTS

A significant number of interference cases (18.5%, N = 400) occurred when the rotational center was placed at the most distal margin of the occlusal surface. The interference was reduced (2.75%, N = 400) but still present at the distal fourth of the occlusal surface. At the distal one-third of the occlusal surface, interference did not occur (0%, N = 400). There was a significant difference between the results of the three rotational centers (p < 0.0001).

CONCLUSIONS

The interference test was not required for a rotational center at the distal third to half of the occlusal surface. However, if the length of the long occlusal rest extends beyond the distal third, an interference test is recommended before final impression.

Elevated Fibroblast Growth Factor Signaling Is Critical for the Pathogenesis of the Dwarfism in Evc2/Limbin Mutant Mice

Ellis-van Creveld (EvC) syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN). While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF) signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome.

The Association Between Gestational Age and Shape Anomalies of the Permanent Dentition

PURPOSE

The purpose of this study was to evaluate the association between gestational age status and the presence of dental anomalies in the permanent dentition.

METHODS

Dental and medical charts and panoramic radiographs of 340 seven- to 18-year-old subjects with a known history of premature birth were assessed retrospectively. The controls were 150 healthy children born at full term. The gestational ages of subjects were recorded and categorized as extremely premature, very premature, late premature, or full term. From the panoramic radiographs, dental anomalies were classified as shape, number, and positional. The total number of anomalies and the number of each type of anomaly was recorded.

RESULTS

There was a statistically significant difference in the odds of having at least one anomaly according to gestational age (P=.04), with decreasing numbers of anomalies as gestational age increased. Subjects of younger gestational ages had significantly more shape anomalies (P<.01); however, no such association occurred for number or positional types of anomalies (P>.05).

CONCLUSIONS

There was a significant association between gestational age status and shape anomalies in the permanent dentition. The number of anomalies increased as gestational age decreased. Subjects born at younger gestational ages had more shape anomalies compared to other types of anomalies.

A Rare Case of Hanhart Syndrome with Mild Developmental Delay

Hanhart Syndrome (OMIM 103300) is an extremely rare syndrome with some congenital malformations. It is characterized by hypoglossia, adactylia/hypodactylia, peromelia of arms and/or legs and micrognathia. The severity of the symptoms can differ from patient to patient. Some affected individuals may have only a part of these clinical features. In this case report, we want to present a Turkish girl with hypoglossia, micrognathia and peromelia who was diagnosed according to the clinical and radiographic findings.

Rare dental manifestation in Simpson-Golabi-Behmel syndrome

Simpson-Golabi-Behmel syndrome (SGBS) is a rare X-linked recessive overgrowth disorder with prominent craniofacial manifestations. Macrodontia is also an uncommon dental anomaly that can be an isolated finding and has been associated with numerous systemic conditions and syndromes. This case report describes this previously unreported dental anomaly, macrodontia, in a patient with SGBS, which may broaden the phenotype of this syndrome. A brief review of the literature on orofacial findings associated with SGBS is also presented.

Predicting Agenesis of the Mandibular Second Premolar from Adjacent Teeth

Early diagnosis of agenesis of the mandibular second premolar (P2) enhances management of the dental arch in the growing child. The aim of this study was to explore the relationship in the development of the mandibular first molar (M1) and first premolar (P1) at early stages of P2 (second premolar). Specifically, we ask if the likelihood of P2 agenesis can be predicted from adjacent developing teeth. We selected archived dental panoramic radiographs with P2 at crown formation stages (N = 212) and calculated the likelihood of P2 at initial mineralisation stage 'Ci' given the tooth stage of adjacent teeth. Our results show that the probability of observing mandibular P2 at initial mineralisation stage 'Ci' decreased as both the adjacent P1 and M1 matured. The modal stage at P2 'Ci' was P1 'Coc' (cusp outline complete) and M1 'Crc' (crown complete). Initial mineralisation of P2 was observed up to P1 'Crc' and M1 stage 'R½' (root half). The chance of observing P2 at least 'Coc' (coalescence of cusps) was considerably greater prior to these threshold stages compared to later stages of P1 and M1. These findings suggest that P2 is highly unlikely to develop if P1 is beyond 'Crc' and M1 is beyond 'R½'.

Allgrove syndrome: a report of a unique case characterised by peculiar dental findings resembling those of ectodermal dysplasia

BACKGROUND

Triple A or Allgrove Syndrome (OMIM#231550) is a rare, autosomal recessive genetic disorder in which patients typically suffer from chronic adrenal insufficiency due to resistance to ACTH (Addison's disease), esophageal achalasia, and defective tear formation (alacrima). The syndrome is caused by mutations in the AAAS gene on chromosome 12q13 encoding a 546 aminoacid protein named alacrimia-achalasia-adrenal insufficiency neurologic disorder (ALADIN), a constituent of eukaryotic nuclear pore complexes.

CASE REPORT

We describe a case of Allgrove Syndrome presenting with anhidrosis and peculiar dental features resembling those of Ectodermal Dysplasia (ED).

CONCLUSION

Given the clinical findings in this case we suggest the hypothesis that the pathogenetic mechanism in Allgrove syndrome is related to the ED.

[The dental collection Hyacinthe Brabant: A pedagogic and scientific tool]

Among the numerous specimens preciously preserved in the Anatomical and Embryological Museum of ULB, there lies also a dental collection assembled by Professor Hyacinthe Brabant. This collection, previously unlabelled, shows several dental anomalies and pathologies as well as tumours. The objective of our study was to conduct an inventory of this collection and to set up an electronic iconographic tool through the Iconography website of ULB. A descriptive study was carried out and it was based on the analysis of 125 models and 90 extracted human teeth. The inspection of the models showed some non-odontological tumours as well as multiple dental anomalies. The extracted teeth showed generalised, coronal or radicular anomalies. The conducted inventory allowed us to classify and label the specimens and therefore to showcase this dental collection which is unique owing to its rich content and didactic display. Finally, the iconographic site will be a useful tool to raise awareness about several dental pathologies and anomalies among students and young practionners.

Considerations on morphological abnormalities of permanent teeth in children with cleft lip and palate

Oral clefts are commonly associated with dental anomalies of number, size, shape, structure, position and eruption affecting both dentitions. Dental malformations may affect the development, growth and functions of the dento-maxillary apparatus (chewing, aesthetics, speech). The purpose of this paper was to assess the dental morphological variations in a group of patients with cleft lip and/or palate (CLP), as compared with a group of healthy subjects. The study sample included 48 patients with various types of CLP (15 girls and 33 boys) aged between 12.6 years and 17.3 years. The control group (without CLP) consisted of 1447 patients (545 girls and 903 boys). The proportion of patients with dental shape anomalies in the control group was 8.6%, while the proportion of patients with dental shape anomalies in the CLP group was 56.3% (p<0.01). With this regards, the frontal area was more affected in CLP group than controls. The most common morphological abnormality in the control group was supplementary cusp, while in the CLP sample it was dilaceration. Teeth from the dental hemiarch affected by CLP were most affected in their morphology.

The Smile Esthetic Index (SEI): A method to measure the esthetics of the smile. An intra-rater and inter-rater agreement study

PURPOSE

To propose a method to measure the esthetics of the smile and to report its validation by means of an intra-rater and inter-rater agreement analysis.

MATERIALS AND METHODS

Ten variables were chosen as determinants for the esthetics of a smile: smile line and facial midline, tooth alignment, tooth deformity, tooth dischromy, gingival dischromy, gingival recession, gingival excess, gingival scars and diastema/missing papillae. One examiner consecutively selected seventy smile pictures, which were in the frontal view. Ten examiners, with different levels of clinical experience and specialties, applied the proposed assessment method twice on the selected pictures, independently and blindly. Intraclass correlation coefficient (ICC) and Fleiss' kappa) statistics were performed to analyse the intra-rater and inter-rater agreement.

RESULTS

Considering the cumulative assessment of the Smile Esthetic Index (SEI), the ICC value for the inter-rater agreement of the 10 examiners was 0.62 (95% CI: 0.51 to 0.72), representing a substantial agreement. Intra-rater agreement ranged from 0.86 to 0.99. Inter-rater agreement (Fleiss' kappa statistics) calculated for each variable ranged from 0.17 to 0.75.

CONCLUSION

The SEI was a reproducible method, to assess the esthetic component of the smile, useful for the diagnostic phase and for setting appropriate treatment plans.

[Late morphological teeth changes in children after chemotherapy]

BACKGROUND

Teeth changes after chemotherapy are of clinical importance, but no morphological studies were conducted on microscopic level.

AIM

To assess morphological changes in teeth developing under chemotherapy.

MATERIALS AND METHODS

Twenty-nine adolescents aged 13-16 years that received chemotherapy at the age of 2-13 were included in the study. Teeth morphology was evaluated by means of clinical and radiological data as well as microscopy of extracted teeth (n=13). Thirty healthy children aged 13-16 and 8 teeth extracted for orthodontic reasons served as a control.

RESULTS

Chemotherapy has arresting impact on teeth development confirmed by aplasia of germs when influenced on stages I-II (p=0.0001), preliminary apexogenesis resulting in shortened roots in teeth at the later stages of growth and development (p=0.01). Enamel and dentine defects usually located in cervical area are also a specific feature, while caries incidence was not higher when compared to control group.

CONCLUSION

Children receiving chemotherapy have high risk of secondary teeth loss because of germs aplasia and extraction of severely decayed teeth. Early diagnostics helps to prevent secondary deformations of dental arches by prompt prosthetic rehabilitation. Root morphology changes should be considered by root canal treatment.

Talon cusps occurring concurrently with dens invaginatus on a permanent maxillary lateral incisor: a case report and literature review

A talon cusp is a prominent accessory horn-like structure that projects from the cingulum or cementoenamel junction of the maxillary or mandibular teeth. It can occur in primary and permanent dentition and can lead to occlusal interference, irritation of the tongue, pulpal necrosis, caries, and periodontal problems. Talon cusp has been reported to affect both sexes, and may be unilateral or bilateral. Talon cusps occur most often on the palatal surface of permanent maxillary incisors. A comprehensive literature review revealed only 6 reported cases of facial talon cusps. A talon cusp occurring simultaneously with dens invaginatus in a tooth is extremely rare; to date, only 9 case reports have been published. This article presents a unique case of concurrent dens invaginatus and palatal and facial talon cusps in the right maxillary central incisor of a 12-year-old girl.

Dental findings in Hamamy syndrome

This paper highlights features of dental rehabilitation of patients with Hamamy syndrome. A 10-year-old boy patient with Hamamy syndrome reported pain in the maxillary left central incisor, and all mandibular incisors. Intraoral clinical and radiographical examination showed enamel hypoplasia, severe dilacerated maxillary left central incisor and mandibular incisors, malocclusion, delayed eruption of teeth, taurodontism, and loss of lamina dura. Root canal treatment, strip crown and composite restorations were performed.

[Odontologic anomaly in the American mink Neovison vison (Carnivora, Mustelidae) and possible reasons for its appearance]

The paper describes the phenomenon of substitution of the reduced M2 with a tooth of a complex structure in the American mink Neovison vison Schreber. The anomaly is observed on three skulls out of the 574 examined (0.52%) and is characterized by a clear localization, identical structure, and symmetrical manifestation. Atypical molars have two roots, equally well-developed paraconid, eokonid, hypoconid, and a less pronounced metaconid. Some possible hypotheses for the anomaly that are considered include disruption in the development of the dental germ, mutation, and phenotypic expression of genes that are characteristic of plesiomorphic species of mustelids. The substantiated viewpoint is that the cause of this phenomenon may be the "awakening of dormant genes" as a result of destabilizing selection and hybrid dysgenesis in the area of contact of farm and feral American minks.

Prevalence and types of dental anomaly in a Thai non-syndromic oral cleft sample

OBJECTIVE

To investigate the prevalence and characteristics of dental anomalies (DAs); missing teeth (MT), dens-evaginatus (D-E), dens-invaginatus, dilaceration,fusion, gemination, macrodontia, microdontia (Micro), supernumerary teeth (SNT), and taurodontism, in permanent teeth among subjects with non-syndromic oral cleft.

MATERIAL AND METHOD

This cross-sectional study was designed to assess DAs from diagnostic records; comprising panoramic radiograph, intraoral photographs, dental casts, and orthodontic clinic charts of 280 Northeastern Thai subjects, mean age 10.3 +/- 3.2 years. Chi-square test was used to compare DA prevalences among cleft phenotypes and genders.

RESULTS

There were one or more teeth with DAs in 89.6% of the study population. Highest prevalence was MT (60.4%) followed by Micro (41.4%), dilaceration (6.4%), SNT (6.1%) , and 0.4% in D-E, fusion, gemination, and taurodontism. The most prevalent MT was found in 70.7% of subjects in bilateral cleft lip and palate group.

CONCLUSION

The two predominant DAs were MT and Micro, higher prevalences being found with the more severe cleft conditions. The most affected teeth were cleft-site lateral incisors. There were no differences in distribution of DA in male and female.

Dental findings in a child with chronic renal failure secondary to cystinosis

Cystinosis is a genetically determined metabolic disorder whose most prominent feature is end-stage renal disease. This case report describes the dental status of a 12-year-old child with a history of chronic renal failure secondary to cystinosis. Observed dental anomalies included enamel hypoplasia and hypocalcification, delayed dental development, and dental agenesis. Oral manifestations of nephropathic cystinosis are not well documented in the literature, so it is very important to highlight the dental characterizations of this complex disease.

Nonsyndromic tooth agenesis patterns and associated developmental dental anomalies: a literature review with radiographic illustrations

Tooth agenesis is one of the most intriguing phenomena, because it is frequently associated with other oral anomalies, structural variations and malformations of other teeth, late eruption, transposition and crowding. The diagnosis can be quite challenging as radiographic examination is critical for the diagnosis but not always possible and the late developing teeth may be sometimes scored developmentally missing. Accurate diagnosis therefore requires radiographic, clinical, and dental cast examinations. It is an important clinical and public health problem. Patients with missing permanent teeth may suffer from a reduced chewing ability, inarticulate pronunciation, and an unfavorable aesthetic appearance. Clinically, early diagnosis of a dental anomaly can alert the clinician to the possible development of other associated dental anomalies in the same patient or family, and avoid the possible sequelae. Understanding of tooth agenesis patterns and their impact on diagnosis, prevention, and eventually therapeutics are becoming integral parts of comprehensive dental care. Dental examination with radiographic screening of hypodontia in early childhood should be emphasized as part of public oral health policy to allow early diagnosis and timely intervention.

Management of bulbous exophytic malformations of permanent mandibular incisors

This paper presents the diagnosis and management of a rare case of bulbous exophytic malformation of three permanent mandibular incisors. An 8-year-old Caucasian girl presented with concerns on the appearance of these teeth. Medical history was noncontributory, and there was no recall of relevant past trauma. Upon clinical examination, 3 permanent mandibular incisors exhibited hard bulbous protuberances in the crown's middle and cervical areas. Radiographic examination assisted by dental computed tomography revealed that these were continuous with the tooth structure, contained no pulpal tissue, and the teeth displayed normal root development. They were excised and the teeth were restored with a thin composite facing. They remained asymptomatic with acceptable esthetics for 4 years. Scanning electron microscopy and histology of the biopsied hard tissue revealed a nonhomogeneous structure resembling anomalously intertwined enamel with predentin and dentin. The etiology of this disturbance of dental development remains unknown.

Macrodontia, shovel-shaped incisors, and multituberculism: probable Ekman-Westborg-Julin trait

Multiple macrodontia is a rare finding and is defined as a condition in which a tooth is significantly larger than normal. Macrodontia may occur as an isolated finding, part of a group of dental anomalies, or as a component of a syndrome with multiple oral and systemic manifestations. The purpose of this paper was to report a case of macrodontia affecting all permanent teeth and exhibiting shovel-shaped maxillary and mandibular incisors and multituberculate molars and premolars. Some or all of this patient's characteristics have been reported in both males and females, with a ratio of 5:2. No inheritance pattern has been established, as these traits have generally occurred spontaneously. As more individuals are identified and as molecular techniques continue to advance, it is probable that a gene or genes responsible for macrodontia and the associated traits will be identified.

Three-dimensional analysis of tooth dimensions in the MSX1-missense mutation

OBJECTIVES

A novel, 3D technique to measure the differences in tooth crown morphology between the MSX1 cases and non-affected controls was designed to get a better understanding of dental phenotype-genotype associations.

MATERIALS AND METHODS

Eight Dutch subjects from a single family with tooth agenesis, all with an established nonsense mutation c.332 C > A, p. Ser 111 Stop in exon 1 of MSX1, were compared with unaffected controls regarding several aspects of tooth crown morphology of incisor and molar teeth. A novel method of quantitative three-dimensional analysis was used to detect differences.

RESULTS

Statistically significant shape differences were observed for the maxillary incisor in the MSX1 family compared with the controls on the following parameters: surface area, buccolingual dimension, squareness, and crown volume (P ≤ 0.002). Molar crown shape was unaffected.

CONCLUSIONS

A better understanding of dental phenotype-genotype associations may contribute to earlier diagnosis of some multiple-anomaly congenital syndromes involving dental anomalies.

CLINICAL RELEVANCE

A "shape database" that includes associated gene mutations resulting from developmental syndromes may facilitate the genetic identification of hypodontia cases.

[Studies of dentition abnormalities in children of the Republic of Armenia for the purpose of personality identification]

This paper reports the results of investigations carried out to elucidate the frequency and the structure of various forms of abnormalities of dentition among the children of the preschool and school age in the Republic of Armenia. These data may be of help for the forensic medical personality identification especially for the expertise of unrecognized corpses. Moreover, these data provide an indirect picture of the prevalence of abnormalities of dentition among the adult population of the country. Specifically they may sometimes be used to identify the ethnic and/or racial background of a person.

Dental anomalies associated with unilateral and bilateral cleft lip and palate

PURPOSE

The purpose of this study was to compare the prevalence of dental anomalies in the primary and permanent dentition of patients with unilateral (UCLP) and bilateral (BCLP) cleft lip with or without palate.

METHODS

One hundred two complete clinical records were randomly selected for review from a university-based cleft palate clinic. Only nonsyndromic UCLP and BCLP cases were further selected for analysis of dental anomalies. The prevalence of 9 dental categories, including anomalies in number, crown structure, position, and maxillary-mandibular relationship, was assessed and compared between UCLP and BCLP cases using Fisher's exact test.

RESULTS

Of the 102 charts evaluated, there were 67 cases of UCLP and 29 cases of BCLP for a total of 96 cases. There was a high prevalence of dental anomalies in primary and permanent teeth; 93% of UCLP cases and 96% of BCLP cases presented with at least 1 dental anomaly. Significant differences ( P <.05) were only found in the prevalence of anodontia of a single tooth (UCLP=39%, BCLP=14%), multiple anodontia (UCLP=22%, BCLP=54%), and anterior malocclusion (UCLP=15%, BCLP=41%).

CONCLUSIONS

There is a high prevalence of dental anomalies associated with orofacial clefts regardless of whether they are unilateral or bilateral cleft lip with or without palate.

[Enamel structure of atypically formed human teeth]

Using light and scanning electron microscopy thin epoxide processed sections of 12 impacted third molars, one molar developed in odontogenic follicular cyst and one tooth-like teratoma were studied. It was established that the 4 impacted teeth and the tooth developed in odontogenic follicular cyst had obvious signs of enamel damage in the form of erosion in the crown fissures. The features of enamel alteration make it possible to interpret the changes as carious process which apparently has endogenous origin. Tooth-like teratoma extracted from ovarian dermoid cyst looked like canine and incisor "hybrid" coronal portion of which is covered with thin enamel layer, marked by obvious signs of multiple erosive lesions of endogenous nature. But unlike alterations in impacted teeth it resembles either fluorosis or enamel hypoplasia.

Pyridoxal phosphate-responsive seizures in a patient with cerebral folate deficiency (CFD) and congenital deafness with labyrinthine aplasia, microtia and microdontia (LAMM)

We present an 8-year-old boy with folate receptor alpha (FRα) defect and congenital deafness with labyrinthine aplasia, microtia and microdontia (LAMM syndrome). Both conditions are exceptionally rare autosomal recessive inherited diseases mapped to 11q13. Our patient was found to have novel homozygous nonsense mutations in the FOLR1 gene (p.R204X), and FGF3 gene (p.C50X). While the FRα defect is a disorder of brain-specific folate transport accompanied with cerebral folate deficiency (CFD) causing progressive neurological symptoms, LAMM syndrome is a solely malformative condition, with normal physical growth and cognitive development. Our patient presented with congenital deafness, hypotonia, dysphygia and ataxia in early childhood. At the age of 6 years he developed intractable epilepsy, and deteriorated clinically with respiratory arrest and severe hypercapnea at the age of 8 years. In contrast to the previously published patients with a FOLR1 gene defect, our patient presented with an abnormal l-dopa metabolism in CSF and high 3-O-methyl-dopa. Upon oral treatment with folinic acid the boy regained consciousness while the epilepsy could be successfully managed only with additional pyridoxal 5'-phosphate (PLP). This report pinpoints the importance of CSF folate investigations in children with unexplained progressive neurological presentations, even if a malformative syndrome is obviously present, and suggests a trial with PLP in folinic acid-unresponsive seizures.

Orthopaedic and dental abnormalities in osteogenesis imperfecta: a review of the literature

Osteogenesis imperfecta is one of the most commonly recognized inheritable disorders of the connective tissue leading to bone fragility. Usually it is associated to a genetic mutation inducing a reduction in collagen quality and entity production. It involves either modification in dentin formation or multiple bone fractures. The authors reviewed the clinical aspects of these disorders, focusing on oral and orthopaedic concerns, especially related to the histological features of the fracture callus, with respect to new trends in pharmacological and surgical treatments of bone fractures. Surgical treatment varies, according to the age of the patient. In children, surgical orthopaedic procedures include multiple osteotomies and the use of telescopic rods. Medical therapy has always to be associated to surgery and is designed to reduce the incidence of fractures, to increase growth velocity and to ally pain in order to improve mobility and independence. Bisphosphonates (BP) are considered potent inhibitors of bone resorption decreasing the osteoclast population and its activity and bone turn over.

Minichromosome maintenance 2 and 5 expressions are increased in the epithelium of hereditary gingival fibromatosis associated with dental abnormalities

INTRODUCTION

Gingiva fibromatosis is a relatively rare condition characterized by diffuse enlargement of the gingiva, which is caused by expansion and accumulation of the connective tissue.

OBJECTIVE

The aim of the present study was to investigate proliferative and apoptotic biomarker expression in normal gingiva and two forms of gingival fibromatosis.

METHODS

Archived tissue specimens of hereditary gingival fibromatosis, gingival fibromatosis and dental abnormality syndrome and normal gingiva were subject to morphological analysis and immunohistochemical staining. The results were analyzed statistically.

RESULTS

Proteins associated with proliferation were found in the nuclei of epithelial cells from the basal and suprabasal layers, whereas apoptotic proteins were detected in the cytoplasm of the upper layers of the epithelium. Increased expressions of minichromosome maintenance proteins 2 and 5 were observed in the gingival fibromatosis and dental abnormality syndrome samples. In contrast, geminin expression was higher in normal gingiva samples. No difference in the expression of apoptotic proteins was observed among the groups.

CONCLUSION

Our findings support a role for augmented proliferation of epithelial cells within the overgrown tissues associated with gingival fibromatosis or dental abnormality syndrome. However, our data suggest that different biological mechanisms may account for the pathogenesis of different types of gingival fibromatosis.

Dental caries and enamel defects in very low birth weight adolescents

OBJECTIVES

The purpose of this study was to examine developmental enamel defects and dental caries in very low birth weight adolescents with high risk (HR-VLBW) and low risk (LR-VLBW) compared to full-term (term) adolescents.

METHODS

The sample consisted of 224 subjects (80 HR-VLBW, 59 LR-VLBW, 85 term adolescents) recruited from an ongoing longitudinal study. Sociodemographic and medical information was available from birth. Dental examination of the adolescent at the 14-year visit included: enamel defects (opacity and hypoplasia); decayed, missing, filled teeth of incisors and molars (DMFT-IM) and of overall permanent teeth (DMFT); Simplified Oral Hygiene Index for debris/calculus on teeth, and sealant presence. A caregiver questionnaire completed simultaneously assessed dental behavior, access, insurance status and prevention factors. Hierarchical analysis utilized the zero-inflated negative binomial model and zero-inflated Poisson model.

RESULTS

The zero-inflated negative binomial model controlling for sociodemographic variables indicated that the LR-VLBW group had an estimated 75% increase (p < 0.05) in number of demarcated opacities in the incisors and first molar teeth compared to the term group. Hierarchical modeling indicated that demarcated opacities were a significant predictor of DMFT-IM after control for relevant covariates. The term adolescents had significantly increased DMFT-IM and DMFT scores compared to the LR-VLBW adolescents.

CONCLUSION

LR-VLBW was a significant risk factor for increased enamel defects in the permanent incisors and first molars. Term children had increased caries compared to the LR-VLBW group. The effect of birth group and enamel defects on caries has to be investigated longitudinally from birth.