Metabolic Bone Diseases Affecting Tooth Eruption: A Narrative Review

Tooth eruption is an essential process for the development of the oral and maxillofacial system. Several inherited and acquired diseases might affect this tightly regulated process, resulting in premature, delayed, or even failed tooth eruption. The purpose of this article is to review the literature and the clinical parameters of metabolic bone diseases that affect tooth eruption. It examines the physiological aspects of tooth eruption and the pathophysiological changes induced by metabolic bone diseases, including changes in bone metabolism, density, and structure. The search strategy for this review included an electronic search in PubMed, Google Scholar, Medline, Scopus, and the Cochrane Library using the following keywords: "metabolic bone diseases", "tooth eruption", "delayed tooth eruption", and each reported disease in combination with "tooth eruption disorders", covering publications up to March 2024 and limited to English-language sources. Understanding the influence of metabolic bone diseases on tooth eruption is crucial for managing both dental and skeletal manifestations associated with these disorders. This review suggests that a multidisciplinary approach to treatment may significantly improve oral outcomes for patients suffering from such conditions. Clinicians should be aware of the specific dental abnormalities that may arise and consider comprehensive evaluations and individualized treatment plans. These findings underscore the need for further research into targeted therapies that address these abnormalities.

Influence of zoledronic acid and pamidronate on tooth eruption in children with osteogenesis imperfecta

INTRODUCTION

Osteogenesis imperfecta (OI) is a congenital disease comprising a heterogeneous group of inherited connective tissue disorders. The main treatment in children is bisphosphonate therapy. Previous animal studies have shown that bisphosphonates delay tooth eruption. The aim of this study is to determine whether patients with OI treated with pamidronate and/or zoledronic acid have a delayed eruption age compared to a control group of healthy children.

METHODS

An ambispective longitudinal cohort study evaluating the age of eruption of the first stage mixed dentition in a group of children with OI (n = 37) all treated with intravenous bisphosphonates compared with a group of healthy children (n = 89). Within the study group, the correlation (Pearson correlation test) between the type of medication administered (pamidronate and/or zoledronic acid) and the chronology of tooth eruption is established, as well as the relationship between the amount of cumulative dose received and tooth eruption.

RESULTS

The age of eruption of the study group was significantly delayed compared to the age of eruption of the control group for molars and lateral incisors (p < 0.05). Patients who received higher cumulative doses had a delayed eruption age compared to those with lower cumulative doses (p < 0.05). There is a high positive correlation between age of delayed tooth eruption and Zoledronic acid administration.

CONCLUSION

Patients with OI have a delayed eruption of the 1st stage mixed dentition compared to a control group of healthy children. This delayed eruption is directly related to the cumulative dose of bisphosphonates and the administration of zoledronic ac.

The impact of craniofacial and dental osteogenesis imperfecta manifestations on oral health-related quality of life of children and adolescents

OBJECTIVE

Craniofacial and oral manifestations of Osteogenesis Imperfecta (OI) can affect the functioning of the stomatognathic system and impact the patient's quality of life. The objective of the study was to evaluate the relationship between craniofacial and oral manifestations and the Oral Health-related Quality of Life (OHRQoL) of OI children and adolescents.

MATERIAL AND METHODS

A total of 30 OI patients aged eight to fourteen years old followed up at the Oral Care Center for Inherited Diseases were enrolled in the research. OHRQoL was assessed using the short form of the Child Perceptions Questionnaire (CPQ) for eight to ten-year-olds (CPQ8-10) and 11 to 14-year-olds (CPQ11-14). The relationship between the OHRQoL index and its assessment domains, OI types, and the presence of dentinogenesis imperfecta (DI), class III malocclusion, and dental agenesis were evaluated.

RESULTS

The median CPQ score of patients was 5, and there was no significant difference in OHRQoL between children and adolescents, nor associated with the disease severity or the presence of DI. The oral manifestations evaluated did not directly impact the patients' OHRQoL.

CONCLUSIONS

The study demonstrated that the perception of OHRQoL is similar for both adolescents and children. The oral symptom was the most relevant domain for the index among patients aged eight to fourteen years while the emotional well-being was the most impacted.

CLINICAL RELEVANCE

this study makes contributions by indicating that addressing dental care for children and adolescents with OI is important in clinical management and better OHRQoL for this population.

Expanding the genetic and clinical spectrum of osteogenesis imperfecta: identification of novel rare pathogenic variants in type I collagen-encoding genes

Introduction

Osteogenesis imperfecta (OI) is a clinically and genetically heterogeneous skeletal disorder. The majority of affected cases are attributed to autosomal dominant pathogenic variants (PVs) found in the COL1A1 and COL1A2 genes, which encode type I collagen. However, PVs in other genes involved in collagen posttranslational modification, processing, crosslinking, osteoblast differentiation, and bone mineralization have also been associated with OI.

Methods

In this study, we present the results of next-generation sequencing (NGS) analysis using a custom panel of 11 genes known to be associated with OI. This clinical study enrolled a total of 10 patients, comprising 7 male and 3 female patients from 7 families, all from the Puglia Region in South Italy, providing a detailed overview of their age, gender, family history, OI type, and non-skeletal features.

Results

The genetic analysis revealed 5 PVs in the COL1A1 gene and 2 PVs in the COL1A2 gene. Importantly, three of these PVs have not been previously reported in the literature. These include two novel heterozygous frameshift PVs in COL1A1 (c.2890_2893del and c.3887del) and one novel heterozygous missense PV in COL1A2 (c.596G>T).

Discussion

The identification of these previously unreported PVs expands the variant spectrum of the COL1A1 and COL1A2 genes and may have implications for accurate diagnosis, genetic counselling, and potential therapeutic interventions in affected individuals and their families.

Dental anomalies in individuals with osteogenesis imperfecta: a systematic review and meta-analysis of prevalence and comparative studies

BACKGROUND

Osteogenesis imperfecta (OI) is a rare genetic disorder primarily caused by mutations in the genes involved in the production of type 1 collagen. OI is also known as brittle bone disease.

OBJECTIVE

This study aims to describe the prevalence of dental anomalies (except dentinogenesis imperfecta) in individuals with OI, and compare the prevalence of dental anomalies between individuals with and without OI and between individuals with different types of OI.

SEARCH METHODS

Searches in PubMed, Web of Science, Scopus, Ovid, and gray literature were performed in October 2022.

SELECTION CRITERIA

Observational studies (with or without a comparison group) that evaluated the prevalence of dental anomalies in individuals with OI. Data collection and analysis: Data items were extracted by two authors. Quality assessment employing the Joanna Briggs Institute checklists and meta-analyses was conducted. Results were provided in prevalence values and odds ratio (OR) / 95% confidence interval (CI). Strength of evidence was determined.

RESULTS

Eighteen studies were included. Most prevalent dental anomalies in individuals with OI included pulp obliteration (46.4%), dental impaction (33.5%), dental impaction of second molars (27%), and tooth agenesis (23.9%). Individuals with OI type III/IV had 20.16-fold greater chance of exhibiting tooth discoloration in comparison with individuals with OI type I (CI: 1.10-370.98). In comparison with the group without OI, the individuals with OI had 6.90-fold greater chance of exhibiting dental impaction (CI: 1.54-31.00). High methodological quality was found in 47% of the studies. Strength of evidence was low or very low.

CONCLUSIONS

Pulp obliteration, dental impaction, and tooth agenesis were the most prevalent dental anomalies in the OI group. Individuals with OI were more likely to have dental impaction than individuals without OI. Individuals with OI type III/IV (severe-moderate) are more likely to have tooth discoloration than individuals with OI type I (mild).

Single cell RNA sequencing reveals mesenchymal heterogeneity and critical functions of Cd271 in tooth development

BACKGROUND

Accumulating evidence suggests that the maxillary process, to which cranial crest cells migrate, is essential to tooth development. Emerging studies indicate that Cd271 plays an essential role in odontogenesis. However, the underlying mechanisms have yet to be elucidated.

AIM

To establish the functionally heterogeneous population in the maxillary process, elucidate the effects of Cd271 deficiency on gene expression differences.

METHODS

p75NTR knockout (Cd271^-/-) mice (from American Jackson laboratory) were used to collect the maxillofacial process tissue of p75NTR knockout mice, and the wild-type maxillofacial process of the same pregnant mouse wild was used as control. After single cell suspension, the cDNA was prepared by loading the single cell suspension into the 10x Genomics Chromium system to be sequenced by NovaSeq6000 sequencing system. Finally, the sequencing data in Fastq format were obtained. The FastQC software is used to evaluate the quality of data and CellRanger analyzed the data. The gene expression matrix is read by R software, and Seurat is used to control and standardize the data, reduce the dimension and cluster. We search for marker genes for subgroup annotation by consulting literature and database; explore the effect of p75NTR knockout on mesenchymal stem cells (MSCs) gene expression and cell proportion by cell subgrouping, differential gene analysis, enrichment analysis and protein-protein interaction network analysis; understand the interaction between MSCs cells and the differentiation trajectory and gene change characteristics of p75NTR knockout MSCs by cell communication analysis and pseudo-time analysis. Last we verified the findings single cell sequencing in vitro.

RESULTS

We identified 21 cell clusters, and we re-clustered these into three subclusters. Importantly, we revealed the cell–cell communication networks between clusters. We clarified that Cd271 was significantly associated with the regulation of mineralization.

CONCLUSION

This study provides comprehensive mechanistic insights into the maxillary- process-derived MSCs and demonstrates that Cd271 is significantly associated with the odontogenesis in mesenchymal populations.

The patient clinical journey and socioeconomic impact of osteogenesis imperfecta: a systematic scoping review

BACKGROUND

Osteogenesis imperfecta (OI) is a rare heritable connective tissue disorder primarily characterised by skeletal deformity and fragility, and an array of secondary features. The purpose of this review was to capture and quantify the published evidence relating specifically to the clinical, humanistic, and economic impact of OI on individuals, their families, and wider society.

METHODS

A systematic scoping review of 11 databases (MEDLINE, MEDLINE in-progress, EMBASE, CENTRAL, PsycINFO, NHS EED, CEA Registry, PEDE, ScHARRHUd, Orphanet and Google Scholar), supplemented by hand searches of grey literature, was conducted to identify OI literature published 1st January 1995-18th December 2021. Searches were restricted to English language but without geographical limitations. The quality of included records was assessed using the AGREE II checklist and an adapted version of the JBI cross-sectional study checklist.

RESULTS

Of the identified 7,850 records, 271 records of 245 unique studies met the inclusion criteria; overall, 168 included records examined clinical aspects of OI, 67 provided humanistic data, 6 reported on the economic impact of OI, and 30 provided data on mixed outcomes. Bone conditions, anthropometric measurements, oral conditions, diagnostic techniques, use of pharmacotherapy, and physical functioning of adults and children with OI were well described. However, few records included current care practice, diagnosis and monitoring, interactions with the healthcare system, or transition of care across life stages. Limited data on wider health concerns beyond bone health, how these concerns may impact health-related quality of life, in particular that of adult men and other family members, were identified. Few records described fatigue in children or adults. Markedly few records provided data on the socioeconomic impact of OI on patients and their caregivers, and associated costs to healthcare systems, and wider society. Most included records had qualitative limitations.

CONCLUSION

Despite the rarity of OI, the volume of recently published literature highlights the breadth of interest in the OI field from the research community. However, significant data gaps describing the experience of OI for individuals, their families, and wider society warrant further research to capture and quantify the full impact of OI.

Craniofacial and dental phenotype of two girls with osteogenesis imperfecta due to mutations in CRTAP

Mutations in CRTAP lead to an extremely rare form of recessive osteogenesis imperfecta (OI). CRTAP deficient mice have a brachycephalic skull, fusion of facial bones, midface retrusion and class III dental malocclusion, but in humans, the craniofacial and dental phenotype has not been reported in detail. Here, we describe craniofacial and dental findings in two 11-year-old girls with biallelic CRTAP mutations. Patient 1 has a homozygous c.472-1021C>G variant in CRTAP intron 1 and a moderately severe OI phenotype. The variant is known to create a cryptic splice site, leading to a frameshift and nonsense-mediated RNA decay. Patient 1 started intravenous bisphosphonate treatment at 2 years of age. At age 11 years, height Z-score was +0.6. She had a short and wide face, concave profile and class III malocclusion, with a prognathic mandible and an antero-posterior crossbite. A panoramic radiograph showed a poor angulation of the second upper right premolar, and no dentinogenesis imperfecta or dental agenesis. Cone-beam computed tomography confirmed these findings and did not reveal any other abnormalities. Patient 2 has a homozygous CRTAP deletion of two amino acids (c.804_809del, p.Glu269_Val270del) and a severe OI phenotype. As previously established, the variant leads to instability of CRTAP protein. Intravenous bisphosphonate treatment was started at the age of 15 months. At 11 years of age her height Z-score was -9.7. She had a long and narrow face and convex profile, maxillary retrusion leading to a class III malocclusion, an edge-to-edge overjet and lateral open bite. Panoramic radiographs showed no dental abnormalities. Cone-beam computed tomography showed occipital bossing, platybasia and wormian bones. In these two girls with CRTAP mutations, the severity of the skeletal phenotype was mirrored in the severity of the craniofacial phenotype. Class III malocclusion and antero-posterior crossbite were a common trait, while dental agenesis or dentinogenesis imperfecta were not detected.

Dental phenotype in an adolescent with osteogenesis imperfecta type XII

Mutation in SP7, encoding the osteoblast-specific transcription factor SP7 (also known as osterix), has been described to cause osteogenesis imperfecta (OI) type XII. However, the exact dental phenotype has not been well described. We report the detailed dental manifestation of a boy known to have OI type XII, presented with impacted dentition, necessitating combined oral and maxillofacial surgical and orthodontic treatment. This case also highlighted the need of multidisciplinary team assessment in this group of children.

Phenotype and molecular characterizations of a family with dentinogenesis imperfecta shields type II with a novel DSPP mutation

Background

Dentinogenesis imperfecta (DGI), Shields type-II is an autosomal dominant genetic disease which severely affects the function of the patients’ teeth. The dentin sialophosphoprotein (DSPP) gene is considered to be the pathogenic gene of DGI-II. In this study, a DGI-II family with a novel DSPP mutation were collected, functional characteristics of DGI cells and clinical features were analyzed to better understand the genotype-phenotype relationship of this disease.

Methods

Clinical data were collected, whole exome sequencing (WES) was conducted, and Sanger sequencing was used to verify the mutation sites. Physical characteristics of the patient’s teeth were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The localization of green fluorescent protein (GFP)-fused wild-type (WT) dentin sialoprotein (DSP) and its variant were evaluated via an immunocytochemistry (ICC) assay. The behaviors of human dental pulp stem cells (hDPSCs) were investigated by flow cytometry, osteogenic differentiation, and quantitative real-time polymerase chain reaction (qRT-PCR).

Results

A novel heterozygous mutation c.53T > G (p. Val18Gly) in DSPP was found in this family. The SEM results showed that the participants’ teeth had reduced and irregular dentinal tubes. The EDS results showed that the Ca/P ratio of the patients’ teeth was significantly higher than that of the control group. The ICC assay showed that the mutant DSP was entrapped in the endoplasmic reticulum (ER), while the WT DSP located mainly in the Golgi apparatus. In comparison with normal cells, the patient’s cells exhibited significantly decreased mineralization ability and lower expression levels of DSPP and RUNX2.

Conclusions

The c.53T > G (p. Val18Gly) DSPP variant was shown to present with rare hypoplastic enamel defects. Functional analysis revealed that this novel variant disturbs dentinal characteristics and pulp cell behavior.

Osteogenesis imperfecta type III: Oral, craniofacial characteristics and atypical radiographic findings oral

Osteogenesis imperfecta (OI) is a disease characterized by decreased bone mineral density, causing susceptibility to bone fractures by mild trauma and bone deformities. The aim of this study was to describe an osteogenesis imperfecta type III clinical case, its craniofacial and oral changes as well as its atypical radiographic findings. An eighteen-year-old, male patient diagnosed with osteogenesis imperfecta type III was referred for dental evaluation; the clinical examination showed the craniofacial and oral changes of the disease such as triangular face, class III malocclusion, anterior open bite and posterior crossbite, dentinogenesis imperfecta presenting amber discoloration. The radiographic examination revealed teeth with pulp chamber obliteration and root canals, however unusual findings were also observed such as: bilateral increase of the mandibular canals and preservation of the pulp chamber and third molar root canals. Our findings show that is essential an adequate knowledge of anatomy, a careful anamnestic evaluation and a complete radiological evaluation of the patient with OI. Key words:Dental anomalies, developmental disability, rare disorders.

Missing and unerupted teeth in osteogenesis imperfecta

INTRODUCTION

Osteogenesis imperfecta (OI) is a genetic disorder characterized by bone fragility and craniofacial and dental abnormalities such as congenitally missing teeth and teeth that failed to erupt which are believed to be doubled in OI patients than normal populations and were associated with low oral health quality of life. However, the etiology of these abnormalities remains unclear. To understand the factors influencing missing and unerupted teeth, we investigated their prevalence in a cohort of OI patients as a function of the clinical phenotype (OI type), the genetic variant type, the tooth type and the onset of bisphosphonate treatment.

METHOD

A total of 144 OI patients were recruited from The Shriners Hospital, Montreal, Canada, between 2016 and 2017. Patients were evaluated using intraoral photographs and panoramic radiographs. Missing teeth were evaluated in all patients, and unerupted teeth were assessed only in patients ≥15 years old (n = 82).

RESULTS

On average, each OI patient had 2.4 missing teeth and 0.8 unerupted teeth, and the most common missing and unerupted teeth were the premolars and the upper second molars, respectively. These phenomena were more prominent in OI type III and IV than in OI type I, and were not sex or age-related. Missing teeth were significantly more common in patients with C-propeptide variants than all other variants (p-value <0.05). Unerupted teeth were significantly more common in patients with α1 and α2 glycine variants or substitutions than in those with haploinsufficiency variants. Early-onset of bisphosphonate treatment would significantly increase the risk of unerupted teeth in patients with OI types III and IV (OR = 1.68, 95% CI (1.15-1.53)).

CONCLUSION

The prevalence of missing and unerupted teeth at the tooth type level in OI patients varies according to the nature of the collagen variants and the OI type. These findings highlight the role of collagen in tooth development and eruption.

Manifestation and Mechanisms of Abnormal Mineralization in Teeth

Tooth biomineralization is a dynamic and complicated process influenced by local and systemic factors. Abnormal mineralization in teeth occurs when factors related to physiologic mineralization are altered during tooth formation and after tooth maturation, resulting in microscopic and macroscopic manifestations. The present Review provides timely information on the mechanisms and structural alterations of different forms of pathological tooth mineralization. A comprehensive study of these alterations benefits diagnosis and biomimetic treatment of abnormal mineralization in patients.

Abnormalities in Tooth Formation after Early Bisphosphonate Treatment in Children with Osteogenesis Imperfecta

Treatment with intravenous bisphosphonate (BP) in children and adolescents with osteogenesis imperfecta (OI) started in Sweden in 1991. No human studies on the role of BP therapy in development of disturbances in tooth mineralization or tooth morphology have been published. The study cohort comprised 219 individuals who were divided into four groups: group 1, BP treatment onset before 2 years of age (n = 22); group 2, BP treatment onset between 2 and 6 years of age (n = 20); group 3, BP treatment onset between 6 and 10 years of age (n = 13); and a control group of patients with OI who had not received BP therapy (n = 164). The chi-square test was used in between-group comparisons of the prevalence of tooth agenesis. The prevalence of tooth agenesis was significantly higher in children who began BP treatment before the age of 2 years (group 1; 59%,) compared to the controls (10%; p < 0.001) and to children who had begun BP therapy between ages 2 and 6 years (group 2; 10%; p = 0.009) or between ages 6 and 10 years (group 3; 8%; p = 0.003). Different types of disturbances in the enamel formation were seen in 52 premolars, where 51 were seen in those who began BP treatment before the age of 2 years. To conclude, starting BP treatment before the age of 2 years increases the risk of abnormalities in tooth formation manifesting as morphological aberrations, tooth agenesis, and enamel defects.

Dental and dentoalveolar dimensions in individuals with osteogenesis imperfecta

OBJECTIVE

This cross-sectional study compared tooth and dental arch dimensions of individuals with Osteogenesis imperfecta (OI) and healthy controls.

MATERIAL AND METHODS

The 37 OI patients and 37 controls were aged 10 to 74 years. Mesio-distal tooth size, dental arch dimensions, and palatal height were measured from dental models. The differences between the patient and control groups were analysed statistically with a t-test, chi-square test, and Mann-Whitney U test.

RESULTS

The average mesio-distal tooth size of individuals with OI was smaller by 0.1 to 0.8 mm, corresponding to 1.4 to 7.3% of the size of the tooth. The patients and controls showed similar anterior-posterior lengths of maxillary and mandibular arches. The OI patient group exhibited increasingly wider maxillary dental arches posterior to the canines and a shallow palate.

CONCLUSIONS

Reduced tooth size is a developmental feature of OI and a shallow palate a characteristic possibly associated with previously documented imparity of vertical jaw development. Observed posterior widening of the dental arches may follow from altered tongue position. Smaller tooth size can be favourable from orthodontic point of view in alleviating crowding, but it might further predispose to fracturing of teeth which is a considerable risk associated with dentine abnormality. The shallow jawbones may initiate development of posterior open bite, rare in general population but relatively often encountered in OI.

Nanoscopic wear behavior of dentinogenesis imperfecta type II tooth dentin

OBJECTIVES

The aim of this study was to investigate the wear behavior of Dentinogenesis imperfecta type II (DGI-II) dentin and elucidate the correlation between its tribological properties and components.

METHODS

The mid-coronal dentin of normal and DGI-II teeth were divided into two groups: perpendicular and parallel to the dentin tubules. The microstructure of dentin was detected using atomic force microscopy (AFM). The wear behavior of dentin was evaluated by nanoscratch tests and scanning electron microscopy (SEM). Meanwhile, changes in molecular groups and chemical composition were analyzed by Raman and Energy-Dispersive X-ray (EDX) tests, respectively. Nanohardness was also evaluated.

RESULTS

AFM images of DGI-II dentin illustrated a decrease in the number of tubules and the tubule diameter. Nanoscratch test showed a higher friction coefficient and a greater depth-of-scratch in DGI-II dentin. The wear resistance of DGI-II dentin was reduced independent of tubule orientation. EDX results indicated that DGI-II dentin mineral content decreased and Raman spectra results showed DGI-II dentin had a decreased collagen matrix structure stability coupled with hypomineralization. Furthermore, a significant reduction in nanohardness and elastic modulus of DGI-II dentin was observed. Regression analysis revealed a close correlation between dentin components and inferior wear resistance.

CONCLUSIONS

All results indicated the wear behavior of DGI-II dentin was significantly deteriorated, presumably caused by the disorder in microstructures and the reduction of chemical composition.

Malocclusion in individuals with osteogenesis imperfecta: A systematic review and meta-analysis

OBJECTIVE

To evaluate whether individuals with osteogenesis imperfecta (OI) are more affected by malocclusion than individuals without OI.

MATERIALS AND METHODS

Searches in PubMed, Ovid, Web of Science, Scopus, Lilacs and gray literature were performed. Data extraction was conducted by two researchers. Risk of bias assessment employing the Newcastle-Ottawa Scale and meta-analysis were conducted. Results were provided with mean difference (MD), odds ratio (OR) and 95% confidence interval (CI). Strength of evidence was determined.

RESULTS

Six cross-sectional studies were included. In comparison with individuals without OI, the group with OI had 19.69-fold greater chance of exhibiting Angle Class III malocclusion (OR = 19.69, CI: 9.00-43.09) and presenting anterior crossbite greater (MD = 6.08, CI: 2.40-9.77). Individuals without OI had a significantly greater ANB angle (MD = 3.88, CI: 1.15-6.61) and SNA angle (MD = 2.11, CI: 0.24-3.98) in comparison with those with OI. No difference between groups was found for SNB (MD = -0.50, CI: -2.21 to 1.21) and open bite (MD = 0.98, CI: -0.29 to 2.25). Most studies included had moderate methodological quality. Strength of evidence was low or very low.

CONCLUSIONS

The occurrence of Angle Class III malocclusion and anterior crossbite was greater among individuals with OI compared to those without OI. These findings can assist stakeholders about the occlusal abnormalities affecting OI individuals.

Bisphosphonate Therapy and Tooth Development in Children and Adolescents with Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a heterogeneous connective tissue disorder characterized by repeated fractures and skeletal disorders. At present, bisphosphonate (BP) therapy is the gold standard for OI treatment. The present retrospective study evaluated the effect of BP therapy on tooth development and eruption of permanent teeth in a cohort of children receiving pamidronate. Three groups were studied: patients with OI who were treated with BPs (n = 45), patients with OI who were not treated with BPs (n = 117), and age- and gender-matched healthy controls (n = 121). Dental age, dental maturity, and tooth eruption were assessed on panoramic radiographs using the methods of Demirjian et al. (Hum Biol 45(2):211-227, 1973) and Haavikko (Suom Hammaslaak Toim 66(3):103-170, 1970) and were evaluated using the t-test, Chi-square test, and the Mann-Whitney U test. Dental age in the study group was significantly (p < 0.05) lower than chronological age compared with both control groups. Dental maturity and the eruption of permanent teeth were also significantly (p < 0.05) delayed in the study group in relation to the two control groups. The dental age was significantly lower (p < 0.001) in patients with OI type III treated with BPs compared with healthy controls and the dental maturation was significantly delayed in patients with OI type IV treated with BPs compared with those not treated. In conclusion, BP therapy in OI patients seems to lower the dental age, delay the dental maturity, and tooth eruption. BP administration before 2 years of age might be a contributing factor.

Mutations in COL1A1/A2 and CREB3L1 are associated with oligodontia in osteogenesis imperfecta

Background

Osteogenesis imperfecta (OI) is a heterogeneous connective tissue disorder characterized by an increased tendency for fractures throughout life. Autosomal dominant (AD) mutations in COL1A1 and COL1A2 are causative in approximately 85% of cases. In recent years, recessive variants in genes involved in collagen processing have been found. Hypodontia (< 6 missing permanent teeth) and oligodontia (≥ 6 missing permanent teeth) have previously been reported in individuals with OI. The aim of the present cross-sectional study was to investigate whether children and adolescents with OI and oligodontia and hypodontia also present with variants in other genes with potential effects on tooth development. The cohort comprised 10 individuals (7.7–19.9 years of age) with known COL1A1/A2 variants who we clinically and radiographically examined and further genetically evaluated by whole-genome sequencing. All study participants were treated at the Astrid Lindgren Children’s Hospital at Karolinska University Hospital, Stockholm (Sweden’s national multidisciplinary pediatric OI team). We evaluated a panel of genes that were associated with nonsyndromic and syndromic hypodontia or oligodontia as well as that had been found to be involved in tooth development in animal models.

Results

We detected a homozygous nonsense variant in CREB3L1, p.Tyr428*, c.1284C > A in one boy previously diagnosed with OI type III. COL1A1 and COL1A2 were the only two genes among 9 individuals which carried a pathogenic mutation. We found rare variants with unknown significance in several other genes related to tooth development.

Conclusions

Our findings suggest that mutations in COL1A1, COL1A2, and CREB3L1 may cause hypodontia and oligodontia in OI. The findings cannot exclude additive effects from other modifying or interacting genes that may contribute to the severity of the expressed phenotype. Larger cohorts and further functional studies are needed.

Impact of fracture characteristics and disease-specific complications on health-related quality of life in osteogenesis imperfecta

Osteogenesis imperfecta (OI) is a connective tissue disease with bone fragility. Several studies have indicated that physical function in adult OI was correlated to the disease severity, but there have been no reports delineating the impact of the fracture characteristics and disease-specific complications on health-related quality of life (HRQoL). The purpose of this study is to clarify the factors impacted on HRQoL in adult OI patients. We conducted a cross-sectional study between July 2016 and March 2018 and sent a questionnaire regarding HRQoL using Short Form-36 (SF-36) to the OI patients at the age of 20 years or older who had a medical history of the investigators' institutions. The 40 patients completely answered the SF-36. Mental component summary and role/social component summary were unremarkable. Physical component summary (PCS) was significantly associated with z-score for height, teeth abnormality, and cardiopulmonary insufficiency (partial regression coefficient, 3.04, - 9.70, and - 11.35; p, < 0.001, 0.047, and 0.025, respectively). PCS was also significantly lower in the patients who had an initial fracture before the age of 2 years than those without occurrence of fractures until 2 years old (25.80 ± 17.15 versus 44.20 ± 16.54; p = 0.002), or those who had lower extremity fractures more than five times as compared with normal populations. Physical function was decreased in OI patients who had fractures before 2 years old, especially in lower extremity. Appropriate medical managements for cardiopulmonary insufficiency are required not only to maintain physical function but also to decrease mortality.

Dental alterations on panoramic radiographs of patients with osteogenesis imperfecta in relation to clinical diagnosis, severity, and bisphosphonate regimen aspects: a STROBE-compliant case-control study

OBJECTIVE

This study aimed to assess the prevalence of dental findings on panoramic radiographs (PRs) of patients with osteogenesis imperfecta (OI) and correlate these results with epidemiologic and medical data.

STUDY DESIGN

A case-control study was conducted with 24 patients with OI and 48 sex- and age-matched controls. Demographic, clinical, and bisphosphonate regimen-related data were recorded. The outcome variables were the presence or absence of dental alterations in PRs. Mann-Whitney U test, Pearson's χ² test, and multinomial logistic regression analysis (95% confidence interval) were used (significance level of 5%).

RESULTS

OI type 4 demonstrated a high prevalence (62.5%), followed by type 1 (37.5%). With regard to prevalence associated with severity, the moderate form was the most prevalent (P = .028). The mean time of intravenous pamidronate regimen was 6.6 ± 4.4 years. Dentinogenesis imperfecta was observed in 75% of patients with OI, and this group showed a high prevalence of dental abnormalities in comparison with controls (P < .05). Bisphosphonate therapy was associated with ectopic teeth (P = .007) and tooth impaction (P = .033). Pulp obliteration was significant with bisphosphonate treatment over a period of 7 years (P = .026).

CONCLUSIONS

This study found a significant prevalence of dental alterations in patients with OI, and certain alterations were associated with bisphosphonate therapy, indicating its influence on the dentin-related physiopathology.

Prenatal diagnosis of fetal skeletal dysplasia using targeted next-generation sequencing: an analysis of 30 cases

Background

This study aims to provide genetic diagnoses for 30 cases of fetal skeletal dysplasia, and a molecular basis for the future prenatal diagnosis of fetal skeletal dysplasia.

Methods

A total of 30 cases of fetal skeletal dysplasia detected with ultrasound between January 2014 and June 2017 were analyzed. Among these fetuses, 15 fetuses had local skeletal malformations, while 15 fetuses had short limb malformations. Samples of fetal umbilical cord blood, amniotic fluid, and/or aborted tissue were collected from all cases. Karyotyping, whole genome sequencing, and targeted next-generation sequencing of skeletal disease-related pathogenic genes were performed, as needed. Blood samples were taken from the parents for verification using Sanger sequencing.

Results

Among the 30 cases of fetal skeletal dysplasia, two cases were diagnosed with trisomy 18. However, none of these cases were identified with any microdeletions or microreplications associated with skeletal dysplasia. Among the 28 chromosomally normal cases with fetal skeletal dysplasia, 21 cases were detected with mutations in genes related to skeletal diseases. Furthermore, collagen gene mutations were detected in six fetuses with short limb malformations, while heterozygous disease-causing mutations in the fibroblast growth factor receptor 3 (FGFR3) gene were detected in seven fetuses. The remaining fetuses carried mutations in other various genes, including tumor protein p63 (TP63), cholestenol delta-isomerase (EBP), cholinergic receptor nicotinic gamma subunit (CHRNG), filamin B (FLNB), and SRY-box 9 (SOX9). Three compound heterozygous mutations in CHRNG, COL11A2 and SOX9 were carried by phenotypically healthy parents.

Conclusion

Targeted next-generation sequencing can significantly improve the prenatal diagnoses of fetal skeletal dysplasia, providing parents with more precision medicine, and improved genetic counseling.

Cone-Beam Computed Tomography of Osteogenesis Imperfecta Types III and IV: Three-Dimensional Evaluation of Craniofacial Features and Upper Airways

This cross-sectional study investigated the natural history of craniofacial deformities in osteogenesis imperfecta (OI) and determined the impact of three-dimensional (3D) analysis on diagnosis and treatment planning in orthodontics and orthognathic surgery in comparison to conventional two-dimensional (2D) cephalometric examination. 3D images of the craniofacial complex were acquired during 1 calendar year using cone-beam computed tomography (CBCT) from a cohort of 41 individuals (aged 11 to 35 years; 28 females) with OI type III (n = 13) or IV (n = 28). 3D evaluation of the craniocervical junction and upper airways was conducted using InVivoTM. 2D lateral cephalogram was constructed, traced, and examined using the University of Western Ontario analysis (DolphinTM). Quantitative and qualitative parameters were compared between OI type III and type IV groups (unpaired t test) and the unaffected population (Z-score). 3D evaluation revealed a high prevalence of craniocervical abnormalities, craniofacial asymmetries, and nasal septum deviation in both OI groups. Mean airway dimensions were comparable to the non-affected population norms, except for 5 individuals who had insufficient airway dimensions. In 2D, the maxilla was retrognathic and hypoplastic, and the mandibular position was convergent with respect to the face, resulting in mandibular prognathism and face height reduction. The 2D trends were more pronounced in OI type III, whereas the 3D craniocervical and airway abnormalities were common in both types. This study illustrates the prevalence of craniofacial and airway anomalies in OI that occur along with facial deformities are not associated with postcranial phenotype and OI type, are apparent only in 3D evaluation, and are likely to influence treatment strategy. For OI patients, a team effort involving a dentist, orthodontist, neurologist, and ear-nose-throat (ENT) practitioner is recommended for successful management of craniofacial deformities.

Osteogenesis Imperfecta: New Perspectives From Clinical and Translational Research

Osteogenesis imperfecta (OI) is a monogenic bone fragility disorder that usually is caused by mutations in one of the two genes coding for collagen type I alpha chains, COL1A1 or COL1A2. Mutations in at least 18 other genes can also lead to an OI phenotype. As genetic testing is more widely used, mutations in these genes are also more frequently discovered in individuals who have a propensity for fractures, but who do not have other typical clinical characteristics of OI. Intravenous bisphosphonate therapy is still the most widely used drug treatment approach. Preclinical studies in OI mouse models have shown encouraging effects when the antiresorptive effect of a bisphosphonate was combined with bone anabolic therapy using a sclerostin antibody. Other novel experimental treatment approaches include inhibition of transforming growth factor beta signaling with a neutralizing antibody and the inhibition of myostatin and activin A by a soluble activin receptor 2B. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research

Caries prevalence and experience in individuals with osteogenesis imperfecta: A cross-sectional multicenter study

OBJECTIVE

Dentinogenesis Imperfecta (DI) forms a group of dental abnormalities frequently found associated with Osteogenesis Imperfecta (OI), a hereditary disease characterized by bone fragility. The objectives of this study were to quantify the dental caries prevalence and experience among different OI-types in the sample population and quantify how much these values change for the subset with DI.

METHODS

To determine which clinical characteristics were associated with increased Caries Prevalence and Experience (CPE) in patients with OI, the adjusted DFT scores were used to account for frequent hypodontia, impacted teeth and retained teeth in OI population. For each variable measured, frequency distributions, means, proportions and standard deviations were generated. Groups means were analyzed by the unpaired t-test or ANOVA as appropriate. For multivariate analysis, subjects with caries experience of zero were compared with those with caries experience greater than zero using logistic regression.

RESULTS

The stepwise regression analysis while controlling for all other variables demonstrated the presence of DI (OR 2.43; CI 1.37-4.32; P = 0.002) as the significant independent predictor of CPE in the final model.

CONCLUSION

This study found no evidence that CPE of OI subjects differs between the types of OI. The presence of DI when controlled for other factors was found to be the significant predictor of CPE.

Oro-dental and cranio-facial characteristics of osteogenesis imperfecta type V

Osteogenesis imperfecta (OI) type V is an ultrarare heritable bone disorder caused by the heterozygous c.-14C > T mutation in IFITM5. The oro-dental and craniofacial phenotype has not been described in detail, which we therefore undertook to evaluate in a multicenter study (Brittle Bone Disease Consortium). Fourteen individuals with OI type V (age 3-50 years; 10 females, 4 males) underwent dental and craniofacial assessment. None of the individuals had dentinogenesis imperfecta. Six of the 9 study participants (66%) for whom panoramic radiographs were obtained had at least one missing tooth (range 1-9). Class II molar occlusion was present in 8 (57%) of the 14 study participants. The facial profile was retrusive and lower face height was decreased in 8 (57%) individuals. Cephalometry, performed in three study participants, revealed a severely retrusive maxilla and mandible, and moderately to severly retroclined incisors in a 14-year old girl, a protrusive maxilla and a retrusive mandible in a 14-year old boy. Cone beam computed tomograpy scans were obtained from two study participants and demonstrated intervertebral disc calcification at the C2-C3 level in one individual. Our study observed that OI type V is associated with missing permanent teeth, especially permanent premolar, but not with dentinogenesis imperfecta. The pattern of craniofacial abnormalities in OI type V thus differs from that in other severe OI types, such as OI type III and IV, and could be described as a bimaxillary retrusive malocclusion with reduced lower face height and multiple missing teeth.

Dental and craniofacial characteristics caused by the p.Ser40Leu mutation in IFITM5

Severe forms of osteogenesis imperfecta (OI) are usually caused by mutations in genes that code for collagen Type I and frequently are associated with craniofacial abnormalities. However, the dental and craniofacial characteristics of OI caused by the p.Ser40Leu mutation in the IFITM5 gene have not been reported. We investigated a 15-year-old girl with severe OI caused by this mutation. She had marked deformations of extremity long bones. There were no clinical or radiological signs of dentinogenesis imperfecta, but one tooth was missing and several teeth were impacted. Cone beam computed tomography revealed a generalized osteopenic appearance of the craniofacial skeleton, bilateral enlargement of mandibular bodies, and areas of cortical erosions. The cranial base and skull showed a generalized granular bone pattern with a mixture of osteosclerosis and osteolysis. Sphenoid and frontal sinuses were congenitally missing. Cephalometric analysis indicated a Class III growth pattern. In this case, the IFITM5 p.Ser40Leu mutation did not affect tooth structure but was associated with deformities in craniofacial bones that resemble those in the other parts of the skeleton.

Homozygosity for CREB3L1 premature stop codon in first case of recessive osteogenesis imperfecta associated with OASIS-deficiency to survive infancy

BACKGROUND

Mutations of the endoplasmic reticulum (ER)-stress transducer OASIS (encoded by CREB3L1), cause severe recessive osteogenesis imperfecta (OI) not compatible with surviving the neonatal period, as has been shown in two unrelated families through a whole gene deletion vs. a qualitative alteration of OASIS. Heterozygous carriers in the described families have exhibited a mild phenotype. OASIS is a transcription factor highly expressed in osteoblasts, and OASIS^-/- mice exhibit severe osteopenia and spontaneous fractures. Here, we expand the clinical spectrum by a detailed phenotypic characterization of the first case of OASIS-associated OI surviving the neonatal period, with heterozygous family members being unaffected.

METHODS

All OI-associated genes were sequenced. Primary human osteoblast-like cell (hOB) and fibroblast (FB) cultures were obtained for qPCR, and steady-state collagen biochemistry. FB, hOB and skin biopsies were ultrastructurally analyzed. Bone was analyzed by μCT, histomorphometry, quantitative backscattered electron imaging (qBEI), and Raman microspectroscopy.

RESULTS

The proband, a boy with severe OI, had blue sclera and tooth agenesis. A homozygous CREB3L1 stop codon mutation was detected by sequencing, while several family members were heterozygotes. Markedly low levels of CREB3L1 mRNA were confirmed by qPCR in hOBs (16%) and FB (21%); however, collagen I levels were only reduced in hOBs (5-10%). Electron microscopy of hOBs showed pronounced alterations, with numerous myelin figures and diminished RER vs. normal ultrastructure of FB. Bone histomorphometry and qBEI were similar to collagen I OI, with low trabecular thickness and mineral apposition rate, and increased bone matrix mineralization. Raman microspectroscopy revealed low level of glycosaminoglycans. Clinical response to life-long bisphosphonate treatment was as expected in severe OI with steadily increasing bone mineral density, but despite this the boy suffered repeated childhood fractures.

CONCLUSIONS

Deficiency of OASIS can cause severe OI compatible with surviving the neonatal period. A marked decrease of collagen type I transcription was noted in bone tissue, but not in skin, and ultrastructure of hOBs was pathological. Results also suggested OASIS involvement in glycosaminoglycan secretion in bone.

Dentinogenesis imperfecta type II in Swedish children and adolescents

Background

Dentinogenesis imperfecta (DGI) is a heritable disorder of dentin. Genetic analyses have found two subgroups in this disorder: DGI type I, a syndromic form associated with osteogenesis imperfecta (OI), and DGI type II, a non-syndromic form. The differential diagnosis between types I and II is often challenging. Thus, the present cross-sectional study had two aims: to (i) investigate the prevalence and incidence of DGI type II among Swedish children and adolescents and (ii) search out undiagnosed cases of DGI type I by documenting the prevalence of clinical symptoms of OI in these individuals. We invited all public and private specialist pediatric dental clinics (n = 47) in 21 counties of Sweden to participate in the study. We then continuously followed up all reported cases during 2014−2017 in order to identify all children and adolescents presenting with DGI type II. Using a structured questionnaire and an examination protocol, pediatric dentists interviewed and examined patients regarding medical aspects such as bruising, prolonged bleeding, spraining, fractures, hearing impairment, and family history of osteoporosis and OI. Joint hypermobility and sclerae were assessed. The clinical oral examination, which included a radiographic examination when indicated, emphasized dental variables associated with OI.

Results

The prevalence of DGI type II was estimated to be 0.0022% (95% CI, 0.0016–0.0029%) or 1 in 45,455 individuals. Dental agenesis occurred in 9% of our group. Other findings included tooth retention (17%), pulpal obliteration (100%), and generalized joint hypermobility (30%). Clinical and radiographic findings raised a suspicion of undiagnosed OI in one individual, a 2-year-old boy; he was later diagnosed with OI type IV.

Conclusions

These results show a significantly lower prevalence of DGI type II than previously reported and point to the importance of excluding OI in children with DGI.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0887-2) contains supplementary material, which is available to authorized users.

Osteogenesis imperfecta: potential therapeutic approaches

Osteogenesis imperfecta (OI) is a genetic disorder that is usually caused by disturbed production of collagen type I. Depending on its severity in the patient, this disorder may create difficulties and challenges for the dental practitioner. The goal of this article is to provide guidelines based on scientific evidence found in the current literature for practitioners who are or will be involved in the care of these patients. A prudent approach is recommended, as individuals affected by OI present with specific dentoalveolar problems that may prove very difficult to address. Recommended treatments for damaged/decayed teeth in the primary dentition are full-coverage restorations, including stainless steel crowns or zirconia crowns. Full-coverage restorations are also recommended in the permanent dentition. Intracoronal restorations should be avoided, as they promote structural tooth loss. Simple extractions can also be performed, but not immediately before or after intravenous bisphosphonate infusions. Clear aligners are a promising option for orthodontic treatment. In severe OI types, such as III or IV, orthognathic surgery is discouraged, despite the significant skeletal dysplasia present. Given the great variations in the severity of OI and the limited quantity of information available, the best treatment option relies heavily on the practitioner’s preliminary examination and judgment. A multidisciplinary team approach is encouraged and favored in more severe cases, in order to optimize diagnosis and treatment.

The Changing Landscape in the Genetic Etiology of Human Tooth Agenesis

Despite much progress in understanding the genetics of syndromic tooth agenesis (TA), the causes of the most common, isolated TA remain elusive. Recent studies have identified novel genes and variants contributing to the etiology of TA, and revealed new pathways in which tooth development genes belong. Further, the use of new research approaches including next-generation sequencing has provided increased evidence supporting an oligogenic inheritance model for TA, and may explain the phenotypic variability of the condition. In this review, we present current knowledge about the genetic mechanisms underlying syndromic and isolated TA in humans, and highlight the value of incorporating next-generation sequencing approaches to identify causative and/or modifier genes that contribute to the etiology of TA.

Mutations in COL1A1 and COL1A2 and dental aberrations in children and adolescents with osteogenesis imperfecta - A retrospective cohort study

Osteogenesis imperfecta (OI) is a heterogeneous group of disorders of connective tissue, caused mainly by mutations in the collagen I genes (COL1A1 and COL1A2). Dentinogenesis imperfecta (DGI) and other dental aberrations are common features of OI. We investigated the association between collagen I mutations and DGI, taurodontism, and retention of permanent second molars in a retrospective cohort of 152 unrelated children and adolescents with OI. The clinical examination included radiographic evaluations. Teeth from 81 individuals were available for histopathological evaluation. COL1A1/2 mutations were found in 104 individuals by nucleotide sequencing. DGI was diagnosed clinically and radiographically in 29% of the individuals (44/152) and through isolated histological findings in another 19% (29/152). In the individuals with a COL1A1 mutation, 70% (7/10) of those with a glycine substitution located C-terminal of p.Gly305 exhibited DGI in both dentitions while no individual (0/7) with a mutation N-terminal of this point exhibited DGI in either dentition (p = 0.01). In the individuals with a COL1A2 mutation, 80% (8/10) of those with a glycine substitution located C terminal of p.Gly211 exhibited DGI in both dentitions while no individual (0/5) with a mutation N-terminal of this point (p = 0.007) exhibited DGI in either dentition. DGI was restricted to the deciduous dentition in 20 individuals. Seventeen had missense mutations where glycine to serine was the most prevalent substitution (53%). Taurodontism occurred in 18% and retention of permanent second molars in 31% of the adolescents. Dental aberrations are strongly associated with qualitatively changed collagen I. The varying expressivity of DGI is related to the location of the collagen I mutation. Genotype information may be helpful in identifying individuals with OI who have an increased risk of dental aberrations.