Dentomaxillofacial variability of cleidocranial dysplasia: clinicoradiological presentation and systematic review

The incidence of congenital pseudarthrosis of the clavicle and review of the literature

The aim of this study was to identify the hitherto unknown incidence of congenital pseudarthrosis of the clavicle (CPC), based on a cohort of continuous livebirths born in our hospital, to review the literature and investigate if there is evidence supporting the published association between left-sided CPC and dextrocardia. From our electronic medical record and radiology databases, we identified all live births and patients with the diagnosis of CPC born from 2000 to 2016. We reviewed the imaging which included one or both clavicles to search for unrecorded CPC cases and reviewed all retrievable CPC publications listed in PubMed and publications quoted within these publications going back to 1910. We identified 87 407 livebirths of which 41 800 had radiological studies done, 14 885 showing one or both clavicles. We found five cases of CPC, two from the electronic database and three from our imaging review, giving an incidence of 1 of 17 481 livebirths. We identified 138 publications reporting paediatric and adult CPC cases and 12 review articles, including 429 patients (187 female; 159 male; 83 unknown) with 456 CPCs and a minimum of 24 additional patients from case reports for which we could not retrieve details. Two publications reported one case of left-sided CPC with dextrocardia, either not showing left/right marking or only showing the CPC with the aortic knob on the same side. We report the first CPC incidence of 0.0057%, provide the by far most inclusive CPC epidemiology based on 429 patients and could not find reliable proof that there has ever been a patient with left-sided CPC which was associated with dextrocardia.

Suspected Endodontic Failure in a Patient with Cleidocranial Dysplasia: A Case Report

A patient's medical history and related dental manifestations can significantly contribute to confounding signs and symptoms leading to a diagnostic challenge. An 18-year-old female patient presented with persistent radiographic radiolucency associated with the apex of a previously treated tooth (tooth 9); asymptomatic apical periodontitis and endodontic failure were suspected. This report presents how a patient's condition of cleidocranial dysplasia had a profound effect on her dental history, which included the presence of multiple supernumerary teeth. Extensive surgical intervention during the patient's childhood was required to remove the supernumerary teeth, which resulted in an endodontic misdiagnosis in her adult life. After clinical and radiographic examination, the patient was diagnosed with a periapical scar. Periapical fibrous scars have a prevalence of between 2.5% and 12% and are a rare healing process with fibrous tissue after surgical and nonsurgical interventions. This report describes the diagnosis and pathophysiology of fibrous scars, including their risk factors and long-term monitoring approaches.

A novel single-base deletion of the RUNX Family Transcription Factor 2 gene associated with cleidocranial dysplasia

Cleidocranial dysplasia (CCD) is a rare, autosomal dominant hereditary disorder characterized by skeletal malformations and dental abnormalities. The purpose of this study was to explore the functional role of a novel mutation in the pathogenesis of CCD. Genomic DNA was extracted from peripheral blood mononuclear cells collected from family members of a Chinese patient with CCD. An analysis of their RUNX Family Transcription Factor 2 (RUNX2) gene sequences was performed by PCR amplification and Sanger sequencing. The function of the mutant RUNX2 was studied by bioinformatics, real-time PCR, western blotting, and subcellular localization analysis. Sanger sequencing identified a novel single-base deletion (NM_001024630.4:c.132delG;NP_001019801.3: Val45Trpfs^* 99) in the RUNX2 gene present in the Chinese patient with CCD. In vitro, functional studies showed altered protein localization and increased expression of mutant RUNX2 mRNA and mutant Runt-related transcription factor 2 (RUNX2). Luciferase reporter assay demonstrated that the novel RUNX2 mutations significantly increased the transactivation activity of RUNX2 on the osteocalcin gene promoter. In conclusion, we identified a patient with sporadic CCD carrying a novel deletion/frameshift mutation of the RUNX2 gene and performed screening and functional analyses to determine the cause of the CCD phenotype. This study provides new insights into the pathogenesis of CCD.3.

Heterozygous pathogenic variants involving CBFB cause a new skeletal disorder resembling cleidocranial dysplasia

BACKGROUND

Cleidocranial dysplasia (CCD) is a rare skeletal dysplasia with significant clinical variability. Patients with CCD typically present with delayed closure of fontanels and cranial sutures, dental anomalies, clavicular hypoplasia or aplasia and short stature. Runt-related transcription factor 2 (RUNX2) is currently the only known disease-causing gene for CCD, but several studies have suggested locus heterogeneity.

METHODS

The cohort consists of eight subjects from five unrelated families partially identified through GeneMatcher. Exome or genome sequencing was applied and in two subjects the effect of the variant was investigated at RNA level.

RESULTS

In each subject a heterozygous pathogenic variant in CBFB was detected, whereas no genomic alteration involving RUNX2 was found. Three CBFB variants (one splice site alteration, one nonsense variant, one 2 bp duplication) were shown to result in a premature stop codon. A large intragenic deletion was found to delete exon 4, without affecting CBFB expression. The effect of a second splice site variant could not be determined but most likely results in a shortened or absent protein. Affected individuals showed similarities with RUNX2-related CCD, including dental and clavicular abnormalities. Normal stature and neurocognitive problems were however distinguishing features. CBFB encodes the core-binding factor β subunit, which can interact with all RUNX proteins (RUNX1, RUNX2, RUNX3) to form heterodimeric transcription factors. This may explain the phenotypic differences between CBFB-related and RUNX2-related CCD.

CONCLUSION

We confirm the previously suggested locus heterogeneity for CCD by identifying five pathogenic variants in CBFB in a cohort of eight individuals with clinical and radiographic features reminiscent of CCD.

A Novel lncRNA Mediates the Delayed Tooth Eruption of Cleidocranial Dysplasia

Delayed eruption of permanent teeth is a common symptom of cleidocranial dysplasia (CCD). Previous studies have focused on the anomaly of osteogenesis resulting from mutations in the Runt-related transcription factor-2 gene (RUNX2). However, deficiencies in osteoclastogenesis and bone resorption, and the epigenetic regulation mediated by long non-coding (lnc)RNAs in CCD remain to be elucidated. Here, a novel osteoclast-specific lncRNA (OC-lncRNA) was identified during the osteoclast differentiation of RAW 264.7 cells transfected with a RUNX2 mutation expression cassette. We further confirmed that OC-lncRNA positively regulated osteoclastogenesis and bone resorption. The OC-lncRNA promoted the expression of CXC chemokine receptor type 3 (CXCR3) by competitively binding to microRNA (miR)-221-5p. The CXCR3–CXC-motif chemokine ligand 10 (CXCL10) interaction and nuclear factor-κB constituted a positive feedback that positively regulated osteoclastogenesis and bone resorption. These results demonstrate that OC-lncRNA-mediated osteoclast dysfunction via the OC-lncRNA–miR-221-5p–CXCR3 axis, which is involved in the process of delayed tooth eruption of CCD.

An overview of the intraoral features and craniofacial morphology of growing and adult Japanese cleidocranial dysplasia subjects

BACKGROUND

Orthodontic treatment for cleidocranial dysplasia (CCD) requires an understanding of the nature of the retained deciduous teeth, supernumerary teeth, delayed eruption of the permanent teeth, and craniofacial morphology from childhood to adulthood. This study aimed to provide an overview of the intraoral and craniofacial characteristics of growing and adult Japanese CCD subjects.

METHODS

We assessed cross-sectionally the intraoral features of 28 CCD subjects (males, 15.3 ± 7.0 years; females, 15.2 ± 5.1 years) using orthopantomograms and photographs. Mean facial diagrams (profilograms) of 3 age groups (5-10 years, 11-14 years, over 15 years: adult) were constructed, and linear and angular measurements of 2 age groups (under 15 years, adult) were performed by using cephalograms. The data were compared with Japanese standards.

RESULTS

A mean of 11.7 and 8.4 retained deciduous teeth, 10.4 and 15.8 erupted permanent teeth were observed in the adult males and females, and a mean of 6.8 and 5.3 supernumerary teeth were observed in all males and females, respectively. A positive correlation was found between the number of supernumerary teeth and the age at initial visit. Cephalometric analysis showed an average to anteriorly positioned maxilla, a tendency for counter-clockwise rotation of the ramus, and a prognathic mandible in all groups.

CONCLUSIONS

The number of supernumerary teeth increased with age. The maxilla was average to anteriorly positioned, and the mandible was counter-clockwise rotated and prognathic for all groups. These characteristic craniofacial morphologies and changes of intraoral conditions at different ages in CCD patients should be considered when proposing rational orthodontic treatment plans.

Demographic, clinical, and radiological characteristics of cleidocranial dysplasia: A systematic review of cases reported in south America

Introduction

Cleidocranial dysplasia (CCD) is a rare disease characterized by craniofacial, skeletal, and oral anomalies. The disease prevalence is estimated to be 1 per million inhabitants; thus, only a few studies have described large cohorts of CCD patients. This study reviewed the clinical-radiological and demographic characteristics of patients with CCD in South America.

Methods

We conducted a systematic review of all cases of CCD reported in South America following the PRISMA guidelines. Demographic information (sex, age at diagnosis, origin, reason for consultation, and family history) was also recorded. CCD signs were divided into “craniofacial” and “skeletal” categories.

Results

A total of 72 cases were included. We found that oral anomalies were the most common reason for consultation leading to a diagnosis in patients, with a median age at diagnosis of 14 years. Fifty percent of the patients were women. Open fontanels or cranial sutures, the presence of at least one of the typical CCD facies (frontal bossing, brachycephaly, hypertelorism, or depression of the nasal bridge), and supernumerary teeth were reported in 92%, 85%, and 88% of cases, respectively. Clavicular dysplasia was present in 98.6% of cases, and other skeletal abnormalities such as scoliosis, pubic symphysis diastasis, and flat feet were found; short stature was present in 71% of cases, and one case presented cognitive deficits.

Conclusion

Although the phenotypic spectrum of CCD is variable, clavicular dysplasia, open fontanels or cranial sutures, dental anomalies, and at least one of the typical CCD facies are present in at least 80% of cases.

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About 70% of patients are diagnosed during childhood or adolescence, mostly due to dental complications.

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Clavicular dysplasia, open fontanel, dental abnormalities, and facies typical of CCD are present in at least 80% of cases.

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The prevalence of CCD signs in the South American population is similar to other patient groups from other populations.

Appropriateness of standard cephalometric norms for the assessment of dentofacial characteristics in patients with cleidocranial dysplasia

OBJECTIVES

Cleidocranial dysplasia (CCD) is a rare skeletal syndrome affecting craniofacial and dental development. As a consequence, conventional cephalometric landmarks may not be valid for CCD patients, and the appropriateness of norms used for the general population should be critically discussed.

METHODS

Five patients 9- to 22-year-old (three females, two males) with CCD were included. Lateral-cephalograms, orthopantomographies, and intra-oral photos were retrospectively analysed. Lateral-cephalograms of 50 normal controls (ten for each CCD patient) matched for age and sex were selected from an online database. Cephalometric measurements of each CCD patients were compared with average values of matched controls using Wilcoxon signed-rank test for paired values (α = 0.05).

RESULTS

In CCD patients, a shortening of the cranial base was present (ΔSN = -17.1 mm, p = 0.043). Thus, the mandible (ΔSNPg = +9.5°, p = 0.043) and the maxilla (ΔSNA = +11.2°, p = 0.043) showed protrusion compared to the cranial base, despite a reduced maxillary (ΔCo-A = -15.1 mm, p = 0.043) and mandibular (ΔCo-Gn = -15.2 mm, p = 0.080) length. The mandibular divergence was reduced (ΔSN/GoGn = -6.4°, p = 0.043), a reduced overbite was present (ΔOverbite = -2.9 mm, p = 0.043), and the interincisal angle was increased (ΔInterincisalAngle = +13.7°, p = 0.043), mainly due to retro-inclination of lower incisors.

CONCLUSIONS

Standard cephalometric norms for the assessment of horizontal jaw position may not be applicable to CCD patients because of a reduced anterior cranial base length compared to normal subjects. Vertical relationships may not be affected, and mandibular hypodivergency was confirmed.

The Association Between Runx Signaling and Craniofacial Development and Disease

PURPOSE OF REVIEW

The Runx family genes (Runx1, Runx2, Runx3, and Cbfb) are important transcriptional regulators in the development of various tissues. We herein highlight the roles of the Runx family genes in morphogenesis in the craniofacial regions and in the pathogenesis of congenital morphological problems in these regions.

RECENT FINDINGS

A recent analysis using conditional Runx mutant animals and a human genetic study identified the novel roles of Runx genes in the development of the tooth, salivary glands, and the palate. In an animal study, Runx1/Cbfb signaling was found to regulate the Lgr5 expression and maintain the stem cells in the dental epithelium in the growing incisors. Aberrant Runx1/Cbfb signaling induced male-specific involution of the convoluted granular cell differentiation of the submandibular gland. In palatogenesis, Runx1/Cbfb signaling regulated the Tgfb3 expression in the fusing palatal epithelium through Stat3 activation. The combination of a human genetic study and a phenotype analysis of mutant animals revealed the various roles of Runx genes in the development of the tooth, palate, and salivary glands. Runx genes have functional redundancy in various tissues, which still hinder the roles of Runx genes in morphogenesis. Future studies may reveal the novel roles of Runx signaling.

Rare Findings in Cleidocranial Dysplasia Caused by RUNX Mutation

Background  Cleidocranial dysplasia (CCD, #MIM119600) is an autosomal-dominant skeletal dysplasia characterized by delayed closure of the cranial sutures, aplasia, or hypoplasia of the clavicles and dental abnormalities. These findings were accompanied by mobile and drooping shoulders, frontal and parietal bossing, hypertelorism, brachycephaly, short stature, supernumerary, and late erupting teeth. Radiographic studies can reveal involvement of multiple bones including skull, chest, pelvis, and limbs. CCD can be diagnosed with clinical and radiological evaluation and validated by molecular studies. Heterozygous loss of function RUNX2 gene, which plays an important role in osteogenesis and differentiation of precursor cells, causes CCD phenotype.

Methods  In this article, we reported five cases from three unrelated families with CCD phenotype. All exons and exonic–intronic boundary regions of RUNX2 gene from five patients were analyzed by polymerase chain reaction amplification and direct Sanger-sequencing.

Results  Our patients had classical CCD phenotype and we detected three different previously described mutations including c.1171C > T, IVS4 + 4delAAGT and c.676G > A. However, nail dysplasia has never been associated with these mutations. Our patients had varying degrees of nail dysplasia. Two of three mutations are related with Runt DNA-binding domain of RUNX2 protein in Wnt signaling and c.1171C > T had effect on proline/serine/threonine-rich (PST) domain. Recently, Wnt signaling pathway was presented as a key regulator of digit and nail differentiation. Our data suggest that RUNX2 gene may have an essential role on embryogenesis of nails, probably by protecting their integrity.

Radiographic features of cleidocranial dysplasia on panoramic radiographs

Purpose

This study aimed to investigate the panoramic imaging features of cleidocranial dysplasia (CCD) with a relatively large sample.

Materials and Methods

The panoramic radiographs of 40 CCD patients who visited Seoul National University Dental Hospital between 2004 and 2018 were analyzed. Imaging features were recorded based on the consensus of 2 radiologists according to the following criteria: the number of supernumerary teeth and impacted teeth; the shape of the ascending ramus, condyle, coronoid process, sigmoid notch, antegonial notch, and hard palate; the mandibular midline suture; and the gonial angle.

Results

The mean number of supernumerary teeth and impacted teeth were 6.1 and 8.3, respectively, and the supernumerary teeth and impacted teeth were concentrated in the anterior and premolar regions. Ramus parallelism was dominant (32 patients, 80.0%) and 5 patients (12.5%) showed a mandibular midline suture. The majority of mandibular condyles showed a rounded shape (61.2%), and most coronoid processes were triangular (43.8%) or round (37.5%). The mean gonial angle measured on panoramic radiographs was 122.6°.

Conclusion

Panoramic radiographs were valuable for identifying the features of CCD and confirming the diagnosis. The presence of numerous supernumerary teeth and impacted teeth, especially in the anterior and premolar regions, and the characteristic shapes of the ramus, condyle, and coronoid process on panoramic radiographs may help to diagnose CCD.

Prosthetic rehabilitation of a patient with cleidocranial dysplasia using dental implants-a clinical report

Adult patients with oral manifestations of untreated syndromic malformations usually exhibit a high degree of suffering. In this clinical report, we describe the implant-supported prosthetic treatment of a patient with cleidocranial dysplasia, a rare autosomal-dominant inherited malformation syndrome. Therapy for oral manifestations of cleidocranial dysplasia should be started in early childhood; however, the 26-year-old patient in the present study had not undergone orthodontic therapy in childhood. The treatment measures performed prior to this study were limited to the removal of several permanent teeth. Surgical pretreatment, placement of six implants each in the maxilla and mandible, and prosthetic restoration are described. The implantation was guided using a three-dimensional template. Long-term immediate temporary restoration and immediate loading of the implants were performed. The definitive prosthetic restoration was completed using fixed, acrylic resin-veneered screw-retained fixed dental prostheses. The clinical and radiological parameters observed in this case suggest that surgical and prosthetic procedure concepts from implantology can be adopted for patients with CCD.

Case series of cleidocranial dysplasia: Radiographic follow-up study of delayed eruption of impacted permanent teeth

This report describes 3 cases of cleidocranial dysplasia (CCD) and presents relevant findings on long-term follow-up radiographic images of impacted permanent teeth with delayed eruption. Radiographic images of 3 CCD patients were reviewed retrospectively. These images were mainly composed of panoramic and skull radiographs, and the follow-up periods were 3, 13, and 13 years, respectively. The distinct features revealed by the images were described, and the eruption state of impacted permanent teeth was evaluated. The features common to the 3 cases were multiple supernumerary teeth, the presence of Wormian bone, underdevelopment of the maxilla and the maxillary sinus, and clavicular hypoplasia. The eruption of impacted permanent teeth was not observed without proper dental treatment in adult CCD cases, even after long time periods had elapsed. When proper orthodontic force was applied, tooth movement was observed in a manner not significantly different from the general population.

Surgical strategy for patients with late-diagnosed minor form of cleidocranial dysplasia: three cases

Introduction: Cleidocranial dysplasia is a genetic disease affecting bone growth. Observations: 3 patients, aged 12, 14, and 15 followed an orthodontic and surgical treatment to solve an eruption issue of the permanent teeth. Temporary teeth were extracted and impacted teeth were progressively exposed by multiple surgeries under local anesthesia. Anchorages were placed on the teeth and a traction started, on incisors and molars first, then on premolars, and finally on canines. The treatments lasted for 6 to 8 years. Comments: These patients presented minor form of cleidocranial dysplasia which only affected the teeth. The difficulty of these cases lied in the lateness of their diagnosis and treatment. Adaptations had to be made to simplify treatment plans (shortened dental arch, premolar extractions, etc.).

Systematic reviews in orthodontics: Impact of the PRISMA for Abstracts checklist on completeness of reporting

INTRODUCTION

This study evaluated and compared the completeness of reporting of abstracts of orthodontics systematic reviews before and after the publication of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Abstracts Checklist (PRISMA-A).

METHODS

Abstracts of systematic reviews and meta-analyses in orthodontics published in PubMed, Latin American and Caribbean Health Sciences Literature, and the Cochrane Database of Systematic Reviews databases before March 23, 2018, that met the predefined inclusion and exclusion criteria, were evaluated using the 12 items of PRISMA-A, scoring each item from 0 to 2. Abstracts were classified into 2 groups: before and after publication of the PRISMA-A checklist. Three calibrated evaluators (intraclass correlation coefficient and kappa > 0.8) assessed the scores for compliance with the checklist. The number of authors, country of affiliation of the first author, performance of meta-analysis, and topic of the article were recorded. A regression analysis was performed to assess the associations between abstract characteristics and the PRISMA-A scores.

RESULTS

Of 1034 abstracts evaluated, 389 were included in the analysis. The mean PRISMA-A score was 53.39 (95% CI, 51.83-54.96). The overall score for studies published after the publication of the checklist was significantly higher than for studies published before (P ≤ 0.0001). The components returning significantly higher scores after publication of PRISMA-A were title (P = 0.024), information from databases (P = 0.026), risk of bias (P ≤ 0.0001), included studies (P ≤ 0.0001), synthesis of results (P ≤ 0.0001), interpretation of results (P = 0.035), financing and conflict of interest (P ≤ 0.0001), and registration (P ≤ 0.0001). These results showed the positive effect of PRISMA-A had on the quality of reporting of orthodontics systematic reviews. Nevertheless, the poor adherence revealed that there is still need for improvement in the quality of abstract reporting.

CONCLUSIONS

The quality of reporting of abstracts of orthodontic systematic reviews and meta-analyses increased after the introduction of PRISMA-A.

Dental radiographic findings in 18 individuals with SATB2-associated syndrome

OBJECTIVE

To characterize the radiographic dental phenotype of individuals with SATB2-associated syndrome (SAS).

MATERIALS AND METHODS

Participants were evaluated by a multidisciplinary team during a concurrent clinic conducted during the 1st international SAS family meeting held in 2017 at a single institution. Whenever possible, panoramic and/or periapical radiographs were obtained in clinic or previously obtained and provided by the caregiver.

RESULTS

Of the 37 individuals evaluated, 18 (12 males, median age 8.5 years) underwent radiographic examination. Dental radiographs revealed anomalies in all individuals starting at 2 years of age. The most consistent finding was delayed development of the mandibular second bicuspids (83%) with other common radiographic findings including delayed development of the roots of the permanent teeth (78%), severely rotated (56%) or malformed teeth (44%), and taurodontism (44%).

CONCLUSIONS

Dental anomalies are fully penetrant and can be documented radiographically in all individuals with SAS.

CLINICAL RELEVANCE

Dental radiographic findings of delayed second premolar development and delayed development of permanent root formation, especially concurrent with findings of taurodontism and malformed teeth, support a clinical suspicion for SAS and should help differentiate SAS from other neurodevelopmental syndromes.

Characterization of dental phenotype in patients with cleidocranial dysplasia using longitudinal data

OBJECTIVE

To investigate the characteristics of the dental phenotype in patients with cleidocranial dysplasia (CCD) using longitudinal data.

MATERIALS AND METHODS

Twelve unrelated Korean CCD patients were observed using a longitudinal series of radiographs and clinical photographs. Statistical analysis was performed on the dental phenotypic data.

RESULTS

Although dysplasia of the clavicles, open fontanelle, and wormian bone were observed in all 12 patients, delayed fusion of the mandibular symphysis was found in four patients. One patient did not have a supernumerary tooth (ST). However, 62 STs were found in 11 patients (mean, 5.6 per patient; range of ST emergence, 5 years 6 months-14 years 8 months; developing position, occlusal to the permanent incisors, canines, and premolars and distal and apical to the permanent molars). The mandibular premolar region was the most frequent area of ST development (50.0%, P < .001). All 12 patients showed impacted permanent teeth (IPT), including one patient without ST (mean, 17.8 per patient). Impaction occurred most frequently in the mandibular premolar region and least frequently in the maxillary molar region (93.8% vs 39.6%, P < .01). The ratio of spontaneous eruption of IPT after removal of retained deciduous teeth and/or ST was highest for the maxillary and mandibular incisors (all 54.6%) and lowest for the mandibular canines and premolars (26.7% and 28.9%, respectively); however, the difference was not significant.

CONCLUSIONS

The emergence time and development position of ST and the root development of IPT should be considered to determine the timing for the removal of ST and forced eruption of IPT.

Developmental Disorders Affecting Jaws

Teeth are housed in mandible and maxilla and are known to undergo variations in clinical presentation depending on the degree of abnormality during growth and development. It is essential to identify these variations in normal anatomy so that appropriate treatment can be initiated to address the anomaly. Some normal anatomic variations are harmless and best left alone, whereas others require intervention. Radiology plays a vital role in identification of such anomalies. This article focuses on the diagnostic radiographic interpretation and strategies to include pertinent differential diagnosis. Also discussed is the importance of advanced imaging and its appropriateness in the diagnosis and interpretation.

Cleidocranial dysplasia syndrome (CCD) with an unusual finding in a young patient

Cleidocranial dysplasia (CCD), an autosomal dominant disorder with a prevalence of 1 in 1,000,000 individuals, presents with a wide range of variability. Dentists are often the first to encounter patients with CCD, some of whom do not show typical manifestations. Since it has similar features to other pathologies, CCD is misdiagnosed as other conditions. A 10-year-old boy suffering from CCD was misdiagnosed as having rickets and was referred for non-eruption of a few permanent teeth along with an unaesthetic facial appearance. Clinically and radiologically, a diagnosis of CCD was made. Currently, management of this patient's orofacial manifestations is underway.

Cleidocranial dysplasia

Cleidocranial dysplasia (CCD) is an autosomal dominant disorder resulting in the skeletal and dental abnormalities due to the disturbance in ossification of the bones. Clavicle is the most commonly affected bone. The prevalence of CCD is one in millions of live births. In this report, we present a case of 10-years-old boy showing features of this condition.

Genetic background of supernumerary teeth

Supernumerary teeth (ST) are odontostomatologic anomaly characterized by as the existence excessive number of teeth in relation to the normal dental formula. This condition is commonly seen with several congenital genetic disorders such as Gardner's syndrome, cleidocranial dysostosis and cleft lip and palate. Less common syndromes that are associated with ST are; Fabry Disease, Ellis-van Creveld syndrome, Nance-Horan syndrome, Rubinstein-Taybi Syndrome and Trico–Rhino–Phalangeal syndrome. ST can be an important component of a distinctive disorder and an important clue for early diagnosis. Certainly early detecting the abnormalities gives us to make correct management of the patient and also it is important for making well-informed decisions about long-term medical care and treatment. In this review, the genetic syndromes that are related with ST were discussed.

Cleidocranial dysplasia with autosomal dominant inheritance pattern

Cleidocranial dysplasia (CCD) is an autosomal dominant disease with a wide range of expression, characterized by clavicular hypoplasia, retarded cranial ossification, delayed bone and teeth development, supernumerary teeth, stomatognathic, craniofacial and skeletal abnormalities. This paper presents a case of CCD in a female with brachycephalic skull, depressed frontal bone and nasal bridge, hypoplastic middle one-third of face with mandibular prognathism and hyper mobility of both shoulders with associated radiographic features. Odontologist is often the first professional who patient of CCD approaches, since there is a delay in the eruption or absence of permanent teeth. The premature diagnosis allows a scope for proper treatment modalities, offering a better life quality for patient.

Developmental disorders of the dentition: an update

Dental anomalies are common congenital malformations that can occur either as isolated findings or as part of a syndrome. This review focuses on genetic causes of abnormal tooth development and the implications of these abnormalities for clinical care. As an introduction, we describe general insights into the genetics of tooth development obtained from mouse and zebrafish models. This is followed by a discussion of isolated as well as syndromic tooth agenesis, including Van der Woude syndrome (VWS), ectodermal dysplasias (EDs), oral-facial-digital (OFD) syndrome type I, Rieger syndrome, holoprosencephaly, and tooth anomalies associated with cleft lip and palate. Next, we review delayed formation and eruption of teeth, as well as abnormalities in tooth size, shape, and form. Finally, isolated and syndromic causes of supernumerary teeth are considered, including cleidocranial dysplasia and Gardner syndrome.

Cleidocranial dysplasia: report of six clinical cases

Cleidocranial dysplasia (CCD) is an autosomal-dominant disorder that occurs due to mutations in the Cbfa 1 gene, also called Runx 2, located on the short arm of chromosome 6, affecting osteoblast skeletal-specific bones that have intramembranous ossification. This condition is characterized by hypoplastic clavicles, short stature, and great clinical significance in the stomatognathic complex, with involvement of facial bones, changes in the eruption patterns, including multiple supernumerary and retained teeth. This study reports six subjects of the same family with CCD identified in the Dentistry Clinic of Oral Diagnosis Department, Universidade Paulista, Campus Sorocaba, Sao Paulo State, Brazil. All cases had clinical and radiographic aspects of this important condition, such as short stature, hypertelorism, severe mobility of the shoulders, and supernumerary and retained teeth. Due to the rare incidence and phenotypic manifestations, CCD can be easily misdiagnosed. The oral commitments are one of the main (functional and aesthetic) causes of complaints in these subjects; and a dentist must establish the diagnosis as early as possible, followed by behaviors and practices that can minimize harmful manifestations of the syndrome and improve health associated with oral and multidisciplinary integration offering improvements in quality of life of these subjects.

Cleidocranial dysplasia: complete clinical, radiological and histological profiles

Cleidocranial dysplasia is an autosomal-dominant condition characterised by widely patent calvarial sutures, clavicular hypoplasia, supernumerary teeth and short stature. Though it is not a very uncommon occurrence, its histopathological features are not frequently reported. This paper presents a similar case with complete clinical, radiological, histological and treatment profiles.

Pure de novo partial trisomy 6p in a girl with craniosynostosis

Duplications of chromosome 6p are rarely reported. We present the case of a girl with a de novo trisomy 6p12.3-p21.1 who showed clinical features characteristic of this syndrome, notably facial anomalies, psychomotor delay, and recurrent respiratory tract infections. The most striking feature, however, was craniosynostosis, manifested by the premature fusion of the right coronal and sagittal sutures. A review of the literature revealed that the presence of abnormal fontanelles and sutures is relatively common among patients with proximal trisomy 6p. Exclusion of the most frequently occurring craniosynostosis mutations, as well as of further chromosomal anomalies in our case, suggest the presence of a gene regulating suture formation within this region. Based on recent findings, we hypothesize that the runt-related transcription factor 2 (RUNX2) may be a reasonable candidate gene for craniosynostosis in such patients.

A 13-year-old Caucasian boy with cleidocranial dysplasia: a case report

Background

Cleidocranial dysplasia (CCD) is a rare congenital autosomal dominant skeletal disorder. The disorder is caused by heterozygosity of mutations in human RUNX2, which is present on the short arm of chromosome 6p21. The incidence of CCD is one per million births. CCD appears spontaneously with no apparent genetic cause in approximately 40% of affected patients, and one in three patients has unaffected parents. The most prevalent features associated with CCD are aplastic or hypoplastic clavicles, supernumerary teeth, failed eruption of permanent teeth, and a hypoplastic maxilla.

Case presentation

A 13-year-old Caucasian boy presented with a chief complaint of delayed eruption of the permanent anterior teeth. The patient was subsequently diagnosed with CCD based on the clinical examination, panoramic X-ray, anterior-posterior and lateral cephalogram, and chest radiograph findings. The details of this case are herein reported because of the extremely low incidence of this disorder.

Conclusions

CCD is of clinical importance in dentistry and medicine because it affects the bones and teeth and is characterized by many changes in skeletal patterning and growth. Particularly in dentistry, CCD is of great clinical significance because is associated with delayed ossification of the skull sutures, delayed exfoliation of the primary teeth, lack of permanent teeth eruption, multiple supernumerary teeth, and morphological abnormalities of the maxilla and mandible. Patients with CCD seek treatment mainly for dental problems. Knowledge of the pathogenesis, clinical characteristics, and diagnostic tools of CCD will enable clinicians to render the appropriate treatment to improve function and aesthetics. Early diagnosis of CCD is crucial for timely initiation of an appropriate treatment approach.

Cleidocranial dysplasia: a review of the dental, historical, and practical implications with an overview of the South African experience

Cleidocranial dysplasia (CCD) is an uncommon but well-known genetic skeletal condition. Several hundred affected persons are members of a large extended family in the Cape Town Mixed Ancestry community of South Africa. The clinical manifestations are often innocuous, but hyperdontia and other developmental abnormalities of the teeth are a major feature and may require special dental management. Over the past 40 years, the authors have encountered more than 100 affected persons in Cape Town. Emphasis has been on dental management, but medical, genetic, and social problems have also been addressed. In this article, we have reviewed the manifestations of the disorder in the light of our own experience, and performed a literature search with emphasis on the various approaches to dental management and treatment options in CCD. Advances in the understanding of the biomolecular pathogenesis of CCD are outlined and the international and local history of the disorder is documented.

Tooth eruption: altered gene expression in the dental follicle of patients with cleidocranial dysplasia

OBJECTIVES

The dental follicle plays an important role in tooth eruption by providing key regulators of osteogenesis and bone resorption. Patients with cleidocranial dysplasia (CCD) exhibit delayed tooth eruption in combination with increased bone density in the maxilla and mandible, suggesting disturbances in bone remodeling. The aim of this study was to determine the expression of genes relevant for tooth eruption and bone remodeling in the dental follicles of patients with CCD and normal subjects.

MATERIAL AND METHODS

Thirteen dental follicles were isolated from five unrelated patients with CCD, and fourteen dental follicles were obtained from 10 healthy individuals. All teeth were in the intraosseous phase of eruption. The expression of RANK, RANKL, OPG, and CSF-1 was determined by quantitative RT-PCR.

RESULTS

In patients with CCD, the mRNA levels of RANK, OPG, and CSF-1 were significantly elevated compared with the control group. Accordingly, the ratios of RANKL/OPG and RANKL/RANK mRNAs were significantly decreased in patients with CCD.

CONCLUSION

The observed alterations in the expression and ratios of the aforementioned factors in the dental follicle of CCD individuals suggest a disturbed paracrine signaling for bone remodeling that could be responsible for the impaired tooth eruption seen in these patients.

Molecular genetics of supernumerary tooth formation

Despite advances in the knowledge of tooth morphogenesis and differentiation, relatively little is known about the aetiology and molecular mechanisms underlying supernumerary tooth formation. A small number of supernumerary teeth may be a common developmental dental anomaly, while multiple supernumerary teeth usually have a genetic component and they are sometimes thought to represent a partial third dentition in humans. Mice, which are commonly used for studying tooth development, only exhibit one dentition, with very few mouse models exhibiting supernumerary teeth similar to those in humans. Inactivation of Apc or forced activation of Wnt/β(catenin signalling results in multiple supernumerary tooth formation in both humans and in mice, but the key genes in these pathways are not very clear. Analysis of other model systems with continuous tooth replacement or secondary tooth formation, such as fish, snake, lizard, and ferret, is providing insights into the molecular and cellular mechanisms underlying succesional tooth development, and will assist in the studies on supernumerary tooth formation in humans. This information, together with the advances in stem cell biology and tissue engineering, will pave ways for the tooth regeneration and tooth bioengineering.

Orthokeratinized odontogenic cyst: a systematic review

OBJECTIVES

The aims of the review were to evaluate the principal clinical and conventional radiographic features of orthokeratinized odontogenic cyst (OOC) by systematic review (SR), and to compare the frequency of OOC between four global groups.

METHODS

The databases searched were the PubMed interface of MEDLINE and LILACS. Only those reports of OOCs that occurred in a consecutive series of OOCs in the reporting authors' caseload were considered.

RESULTS

37 reports on 36 case series were included in the SR. OOC affected males twice as frequently and the mandible almost 2.5 times as frequently. Although the mean age at first presentation was 35 years, the largest proportion of cases first presented in the third decade for the Western, East Asian and Latin American global groups. Seven reports included details of at least one clinical finding. 11 reported case series included at least 1 radiological feature. All OOCs were radiolucent, 93% were unilocular and 68% were associated with unerupted teeth. 28% of the reported case series included follow up. 4% of OCC recurred and all of these were in the Western global group.

CONCLUSIONS

Although one feature of OOCs is that they are unlikely to recur, some do. Not only is there a lack of long-term follow up of large series with long-term outcomes of OOC, but there is a paucity of clinical and radiological details of OOC at initial presentation.

Complete cleft sternum associated with clavicular hypoplasia and pectus excavatum

A sternal cleft is a rare congenital and developmental disorder. In general, this disorder is associated with skeletal and extraskeletal abnormalities (eg, Cantrell syndrome), but isolated sternal clefts have also been reported. A sternal cleft with pectus excavatum is a rare congenital abnormality. We present a complete sternal cleft with right-sided clavicular hypoplasia and pectus excavatum in a 31-year-old female patient.

Ossifying fibroma: a systematic review

OBJECTIVES

The aim was to evaluate the principal features of ossifying fibroma (OF) by systematic review (SR), and to compare their frequencies among four global groups.

METHODS

The databases searched were the PubMed interface of MEDLINE and LILACS. Only those reports of OFs that occurred in a series in the reporting authors' caseload were considered. All cases were confirmed fibro-osseous lesions histopathologically. The SR-included series had also to have used radiographs.

RESULTS

Of the 64 reports (including the Hong Kong report) considered, 32 reports and a total of 781 cases were included in the SR. Ten SR-included series were in languages other than English. OF affected females more frequently, but was three times more prevalent in the mandible. The mean age at first presentation was 31 years. The decade with the greatest frequency was the fourth. Females were in the majority except in the first decade. The main symptom in 66% of all SR-included cases was swelling (including deformation of the jaws). 31% were found incidentally. 84% of cases displayed buccolingual expansion; half of the mandibular cases exhibited downward displacement of the lower border of the mandible and 90% of maxillary cases involved the maxillary antrum. Only 28% of reports included follow-up; 12% of cases recurred or were reactivated.

CONCLUSIONS

Although long-term follow-up of large series that would have revealed the long-term outcomes of OF was lacking, a 12% recurrence rate is clinically significant and suggests that OFs should be considered for long-term follow-up.

The significance of RUNX2 in postnatal development of the mandibular condyle

OBJECTIVE

RUNX2, in the Runt gene family, is one of the most important transcription factors in the development of the skeletal system. Research in recent decades has shown that this factor plays a major role in the development, growth and maturation of bone and cartilage. It is also important in tooth development, mechanotransduction and angiogenesis, and plays a significant role in various pathological processes, i.e. tumor metastasization. Mutations in the RUNX2 gene correlate with the cleidocranial dysplasia (CCD) syndrome, important to dentistry, particularly orthodontics because of its dental and orofacial symptoms. Current research on experimentally-induced mouse mutants enables us to study the etiology and pathogenesis of these malformations at the cellular and molecular biological level. This study's aim is to provide an overview of the RUNX2 gene's function especially in skeletal development, and to summarize our research efforts to date, which has focused on investigating the influence of RUNX2 on mandibular growth, which is slightly or not at all altered in many CCD patients.

MATERIALS AND METHODS

Immunohistochemical analyses were conducted to reveal RUNX2 in the condylar cartilage of normal mice and of heterozygous RUNX2 knockout mice in early and late growth phases; we also performed radiographic and cephalometric analyses.

RESULTS

We observed that RUNX2 is involved in normal condylar growth in the mouse and probably plays a significant role in osteogenesis and angiogenesis. The RUNX2 also has a biomechanical correlation in relation to cartilage compartmentalization. At the protein level, we noted no differences in the occurrence and distribution of RUNX2 in the condyle, except for a short phase during the 4th and 6th postnatal weeks, so that one allele might suffice for largely normal growth; other biological factors may have compensatory effects. However, we did observe small changes in a few cephalometric parameters concerning the mandibles of heterozygous knockout animals. We discuss potential correlations to our findings by relating them to the most current knowledge about the RUNX2 biology.

Fibrous dysplasia: a systematic review

OBJECTIVES

To evaluate the principal features of fibrous dysplasia (FD) by systematic review (SR) and to compare their frequencies between four global groups.

METHODS

The databases searched were the PubMed interface of Medline and LILACS. Only those reports of FD which occurred in a series in the reporting authors' caseload were considered. All cases were confirmed fibro-osseous lesions histopathologically. The SR-included series must also have included radiographs.

RESULTS

Of the 106 reports considered (including the Hong Kong report), 31 reports and a total of 788 cases were included in the SR. 11 SR-included series were in languages other than English. FD affected both genders equally, but was 50% more prevalent in the maxilla. The mean age at first presentation was 24 years. The decade with the greatest frequency was the second, in which males accounted for 63%. The main symptom in 90% of all SR-included cases was swelling (including deformation of the jaws). Not one SR-included case directly involved the ocular apparatus. All cases displayed buccolingual expansion; all mandibular cases exhibited downward displacement of the lower border of the mandible and almost all maxillary cases involved the maxillary antrum. Only 35% of reports included follow-up; 18% of cases recurred or were reactivated. Not one case displayed sarcomatous change.

CONCLUSIONS

Long-term follow-up of large series that would have revealed the long-term outcomes of FD was lacking. This is necessary because many cases do not burn out at the end of adolescence, as expected of a hamartoma, but are reactivated.

Clinical spectrum of cleidocranial dysplasia: a case report

Background

Cleidocranial dysplasia is a developmental anomaly of the skeleton and the teeth. This condition may be inherited, be transmitted as dominant characteristics in either sex, or even may appear spontaneously. It presents with skeletal defects of several bones, like partial or complete absence of clavicles, late closure of the fontanels, presence of open skull sutures and multiple wormian bones.

Case presentation

In this case report, we describe an otherwise healthy 30 year-old male with a chief complaint of missing anterior maxillary and Mandibular teeth.

Conclusion

Cleidocranial dysplasia is very rare in occurrence, incidence being 1: 1,000,000. Since early diagnosis of cleidocranial dysplasia is essential for initiating the appropriate treatment approach, clinicians should be aware of the characteristic features. We report a case of cleidocranial dysplasia because of its rarity.

Focal cemento-osseous dysplasia: a systematic review

OBJECTIVES

To evaluate the principal features of focal cemento-osseous dysplasia (FocCOD) by systematic review (SR) and to compare their frequencies between four global groups.

METHODS

Alternative names for FocCOD were used as search terms. The databases searched were the PubMed interface of Medline and LILACS (Literature Index for Latin-America and the Caribbean; Biblioteca Regional de Medicina (BIREME)). Only those reports of FocCODs which occurred in a series in the reporting authors' caseload were considered. All cases used radiographs and were confirmed fibro-osseous lesions histopathologically.

RESULTS

Of the 20 series considered, 10 were included in the SR. Five SR-included series were of East Asian communities. 64% of all SR-included cases were found incidentally. FocCOD predominantly affects females and the mandible. The three predominant radiological presentations varied significantly between reports.

CONCLUSIONS

The two at-risk global communities appear to be East Asians and those of black African origin. Although there appears to be little difference between East Asians and non-East Asians, the significant differences between them with regards to the predominant radiological presentation could suggest that either all communities vary in their presentation or that most, if not all, did not reflect the true frequency within their communities. Long-term follow-up of large series that would have revealed the long-term outcomes of FocCODs was lacking. This is necessary because of both FocCOD's predilection of edentulous areas, increasingly required for osseointegrated implants, and its wide differential diagnosis, which includes some lesions normally treated by surgery.

Craniofacial and temporal bone CT findings in cleidocranial dysplasia

Cleidocranial dysplasia (CCD) is a multistructural polyostotic genetic disorder that results from mutation of the CBFA1 gene. Hearing loss is a frequent finding in CCD. We describe the CT craniofacial findings in CCD and provide a comprehensive discussion of the CT temporal bone findings in these patients.

An epidemiological study of hyperdontia in American blacks and whites

OBJECTIVE

To test the null hypothesis that American blacks do not have a higher frequency of extra permanent teeth than whites.

MATERIALS AND METHODS

Panoramic radiographs of adolescent orthodontic patients, either American whites (n = 1100) or American blacks (n = 600), were reviewed systematically.

RESULTS

The frequencies of supernumerary incisors, premolars, and molars were each significantly more common in blacks. While incisors are the most common extra teeth in whites (and extra molars are least common), just the opposite ranking occurs in blacks. Overall, the odds ratio was 8.8 (95% confidence limits = 3.9, 20.0), confirming that American blacks are significantly more likely (almost 9 times more likely) to possess extra permanent teeth than American whites.

CONCLUSIONS

The hypothesis is rejected. Both the frequencies and the patterns of extra permanent teeth are significantly different in blacks and whites, suggesting different frequencies of the relevant (but unidentified) factors governing the developmental mechanisms that result in hyperdontia.

[Cleidocranial dysplasia. Description and analysis of a patient cohort]

BACKGROUND

Cleidocranial dysplasia (CCD) is a rare dysplasia of bony and dental tissue. Characteristic are typical craniofacial and dental findings including morphological anomalies. CCD is possibly the only general syndrome that can be diagnosed based on the dental findings alone. CCD correlates with mutations in the RUNX2 gene.

PURPOSE

The present interdisciplinary study correlates phenotypic findings with genetic variations in the corresponding gene.

PATIENTS AND METHODS

The coding sequence of the RUNX2 gene from 31 CCD patients from 20 families was analyzed using molecular genetic methods including polymerase chain reaction and direct sequencing. The craniofacial and dental findings of each patient were evaluated according to a standardized scoring scheme and tested with homogeneity analysis for general phenotypic findings.

RESULTS

Several mutations of the RUNX2 gene were identified. Depending on the mutation type, they showed different distribution patterns within the gene coinciding with the functional domains of the gene product. With homogeneity analysis of the phenotype cardinal (especially dental findings) and minor findings (pneumatization disturbances, Wormian bones) were identified. In combination with the genetic data, the statistical analysis showed that loss-of-function mutations of the RUNX2 gene result in a milder markedness of the CCD phenotype than gain-of-function or decrease-of-function mutations.

CONCLUSIONS

We found that type and location of a specific mutation within the RUNX2 gene might have an impact on the expressivity of CCD. Due to the limited sampling size this hypothesis must be verified by investigations in larger patient groups.

Cleidocranial Dysplasia: Diagnostic Criteria and Combined Treatment

Cleidocranial dysplasia (CCD) is an uncommon, generalized skeletal disorder characterized by delayed ossification of the skull, aplastic or hypoplastic clavicles, and serious, complex dental abnormalities. There are many difficulties in the early diagnosis of CCD because a majority of the craniofacial abnormalities becomes obvious only during adolescence. In the present case, a hypoplastic midface, a relative prognathia of the mandible, and close approximation of the shoulders in the anterior plane were the conspicuous extraoral findings. Prolonged exfoliation of the primary dentition, unerupted supernumerary teeth, and the irregularly and partially erupted secondary dentition produced occlusional anomalies. The presence of the second permanent molars together with the primary dentition and wide spacing in the lower incisor area were typical dental signs. Gradual extraction of the supernumerary teeth and over-retained primary teeth was the first step of oral surgery. This was followed by a surgical exposure of the unerupted teeth by thinning of the cortical bone. Orthodontic treatment was aimed at parallel growth of the jaws. Removable appliances were used to expand the narrow maxillary and mandibular arches, and a Delaire mask compensated for the lack of sagittal growth of the upper jaw. Temporary functional rehabilitation was solved by partial denture. When the jaws have been fully developed, implant insertions and bridges are the therapeutic measures. The reported case and the literature data support the importance of the early diagnosis and interdisciplinary treatment of CCD.