Dental-craniofacial manifestation and treatment of rare diseases

Leukemia and Lymphoma Mimicking Periapical Conditions Resulting in Endodontic Treatment: A Systematic Review

INTRODUCTION

Leukemia and lymphoma mimicking periapical conditions can lead to significant diagnostic pitfalls. Guidance for endodontists in managing such cases is barely explored. This systematic review aimed to summarize the clinicopathologic, imaging, and management aspects of leukemia/lymphoma that mimicked periapical conditions and resulted in endodontic treatment.

METHODS

Searches were conducted in PubMed, Embase, Scopus, Web of Science, and LILACS, supplemented by manual scrutiny and gray literature. Case reports and/or case series were included. Critical appraisal of the studies was performed using the Joanna Briggs Institute tool.

RESULTS

Among 3,617 identified records, 32 studies involving 37 individuals (mean age 43.6 years; male-to-female ratio 1.2:1) were included. Diffuse large B-cell lymphoma was diagnosed in 21 (56.8%) individuals. The anterior maxilla and posterior mandible were the most frequently affected sites (29.7% each). Radiographically, 97.3% of the lesions exhibited radiolucency in the periapical region. Endodontic treatment preceded the diagnosis of leukemia/lymphoma in 94.6% of cases, while retreatment occurred in 5.4%. The mean time to final diagnosis was 4.9 months.

CONCLUSION

Leukemia and lymphoma can be misdiagnosed as periapical conditions, leading to inappropriate endodontic treatments and delayed diagnoses. Endodontists should become familiar with the broad clinicoradiographic spectrum of these rare, but potentially life-threatening hematolymphoid malignancies.

Oral and Maxillofacial Manifestations of Kallmann Syndrome: A Systematic Analysis of the Literature

AIMS

Kallmann syndrome (KS) is a rare genetic disorder characterized by congenital hypogonadotropic hypogonadism and varied clinical features. Despite its recognition, the oral and maxillofacial manifestations remain poorly understood. This study synthesized clinical aspects and management of KS-related oral and maxillofacial alterations.

METHODS

Searches were conducted in the PubMed, Web of Science, Scopus, Embase, and LILACS databases, supplemented by manual scrutiny and gray literature. Case series and/or case reports were included. The Joanna Briggs Institute tool was employed for critical appraisal of the studies.

RESULTS

A total of 46 studies comprising 108 cases were included. The mean age of individuals was 19.8 (±12.6) years, and there was a marked predominance of males (79.3%). Cleft lip/palate (32.7%) was the predominant oral condition, followed by high-arched palate (21.7%), and dental agenesis (19.8%). Oral treatment consisted of corrective surgery of the cleft lip and/or palate (n = 9), myoplasty (n = 1), and tooth extraction/orthodontic treatment (n = 1). Hyposmia/anosmia (71.3%) was the most frequently reported manifestation.

CONCLUSION

Early diagnosis and interdisciplinary collaboration are essential for addressing the complex nature of KS-related oral and maxillofacial alterations and improving patient outcomes. The scarcity of data on oral treatment underscores the need for additional research and clinical attention in this field.

Impaired salivary gland function in children with osteogenesis imperfecta: a case-control study

OBJECTIVES

The aim of the present study was to evaluate salivary gland function and oral health status in Osteogenesis imperfecta (OI) children, comparing to a control group, and to investigate the possible influence of bisphosphonate (BP) treatment.

MATERIALS AND METHODS

Patients aged 8-15 years with any OI molecularly confirmed and gender-matched healthy control were consecutively recruited at the Section of Pediatric Dentistry (Dental School-University of Turin). Comprehensive dental examinations were conducted to evaluate carious lesions, plaque and gingival index, stimulated saliva flow rate, pH, and buffer capacity.

RESULTS

A total al of 22 OI patients (mean age: 10.7 ± 2.4 years) and 22 age- and gender-matched healthy controls (mean age: 10.3 ± 2.3 years) were consecutively enrolled. In OI patients reduced saliva quality and quantity and poor oral health, were observed compared to healthy peers. OI subjects exhibited significantly lower stimulated salivary flow rates (SFR; P < 0.001), higher gingival inflammatory status (P = 0.003) and carious experience in both the deciduous (P = 0.038) and permanent dentition (P = 0.005) Stratifying data based on BP assumption, statistically significant differences in resting (P = 0.024) and stimulated SFR (P = 0.019) were observed as compared to OI subjects not using BP drugs.

CONCLUSIONS

Pediatric OI patients show reduced SFR and poor oral health, highlighting the need for regular screenings and early salivary management.

CLINICAL RELEVANCE

Impairment of salivary gland function is suggested by these preliminary data in pediatric patients with OI.

Craniofacial disorders and dysplasias: Molecular, clinical, and management perspectives

There is a wide spectrum of craniofacial bone disorders and dysplasias because embryological development of the craniofacial region is complex. Classification of craniofacial bone disorders and dysplasias is also complex because they exhibit complex clinical, pathological, and molecular heterogeneity. Most craniofacial disorders and dysplasias are rare but they present an array of phenotypes that functionally impact the orofacial complex. Management of craniofacial disorders is a multidisciplinary approach that involves the collaborative efforts of multiple professionals. This review provides an overview of the complexity of craniofacial disorders and dysplasias from molecular, clinical, and management perspectives.

Management of a supernumerary tooth fused to the labial surface of a permanent maxillary central incisor

Key Clinical Message

Management of supernumerary teeth fused to the labial surface of permanent maxillary central incisors would require a multidisciplinary approach comprising of endodontic treatment, periodontal recontouring, and cosmetic composite restoration.

Abstract

The reported cases of supernumerary teeth fused to the labial surface of maxillary central incisors are rare. Such cases need multidisciplinary approaches. Herein, management of a supernumerary tooth fused to the labial surface of a maxillary central incisor is reported. Due to the presence of a communication path between the root canal systems of the two fused teeth, root canal therapy was performed first for the maxillary left central incisor and the supernumerary tooth. The crown of the supernumerary tooth was then removed in a surgical setting while preserving the root to maintain the thin covering of alveolar bone and prevent future periodontal problems. Subsequently, an esthetic composite restoration was performed.

Development of a novel patient-reported outcome measure for orthognathic surgery

OBJECTIVES

This study aimed to develop a new patient-reported outcome measure (PROM) to systematically and scientifically evaluate patients' subjective feelings after orthognathic surgery.

METHODS

A literature review and semi-structured interviews were conducted to construct a conceptual framework and an item pool, followed by expert and patient surveys for measure construction. We conducted a clinical investigation to test the feasibility, reliability, and content validity of this measure.

RESULTS

The conceptual framework included four domains: psychological health, physiological health, social function, and satisfaction, and 33 items were included in the survey. Following the expert analysis, 31 items remained in the draft. The clinical investigation showed a 100% recovery and completion rate and good reliability, with Cronman-Brown formula coefficients of 0.893 and 0.944, respectively.

CONCLUSIONS

A new outcome measure to evaluate patients' subjective feelings after orthognathic surgery was successfully developed, and the clinical investigation demonstrated that the PROM had satisfactory feasibility, reliability, and validity. Further studies are possible based on our PROM, and data on a larger scale may reveal more information on patients' subjective feelings about orthognathic surgery.

CLINICAL SIGNIFICANCE

The novel PROM provides a systematic and scientific way to evaluate the patient's subjective feelings to help surgeons obtain complete patient-reported information after orthognathic surgery. Additionally, standardised multicentre research on patients' subjective feelings using our PROM is possible and could improve the effectiveness of the evaluation and help maintain treatment quality.

ADP-ribose-acceptor hydrolase 2 ( Arh2 ) deficiency results in cardiac dysfunction, tumorigenesis, inflammation, and decreased survival

ADP-ribosylation is a reversible reaction with ADP-ribosyltransferases catalyzing the forward reaction and ADP-ribose-acceptor hydrolases (ARHs) hydrolyzing the ADP-ribose acceptor bond. ARH2 is a member of the 39-kDa ARH family (ARH1-3), which is expressed in heart and skeletal muscle. ARH2 failed to exhibit any in vitro enzymatic activity. To determine its possible in vivo activities, Arh2 -knockout (KO) and - heterozygous (Het) mice were generated using CRISPR-Cas9. Arh2 -KO mice exhibited decreased cardiac contractility by MRI, echocardiography and dobutamine stress with cardiomegaly and abnormal motor function. Arh2 -Het mice showed results similar to those seen in Arh2 -KO mice except for cardiomegaly. Arh2 -KO and -Het mice and mouse embryonic fibroblasts (MEFs) developed spontaneous tumors and subcutaneous tumors in nude mice. We identified 13 mutations in Arh2 -Het MEFs and heterozygous tumors, corresponding to human ARH2 mutations in cancers obtained from COSMIC. Of interest, the L116R mutation in Arh2 gene plays a critical role in aggressive tumorigenesis in nude mice, corresponding to human ARH2 mutations in stomach adenocarcinoma. Both genders of Arh2 -KO and -Het mice showed increased unexpectedly deaths and decreased survival rate during a 24-month observation, caused by tumor, inflammation, non-inflammation (e.g., cardiomegaly, dental dysplasia), and congenital diseases. Thus, Arh2 plays a pivotal role in cardiac function, tumorigenesis, inflammation, and overall survival.

Oral manifestations of Chediak-Higashi syndrome: A systematic review

Chediak-Higashi syndrome (CHS) is an autosomal recessive disorder characterized by leukocytes with giant secretory granules and a myriad of clinical features. However, it is unknown whether oral lesions are part of the syndrome or are refractory to systemic treatment. Herein, we integrated the available data published in the literature on the oral manifestations of individuals with CHS. Searches on PubMed, Web of Science, Embase, Scopus, and LILACS were conducted to identify studies published up to March/2022. The Joanna Briggs Institute tool was used for the critical appraisal of studies. Fourteen articles (21 cases) were detected. The mean age of individuals was 15.9±8.8 years. There was a slight predominance of males (52.4%). The major manifestation was periodontal disease (81%), although ulceration of the oral mucosa (14.3%), gingival/labial abscess (4.8%), and periodontal abscess (4.8%) were also reported. Oral rehabilitation including dental implants (9.5%) was performed after tooth losses due to the poor prognosis of periodontal therapy. CHS is usually diagnosed in an early stage due to its systemic manifestations such as classic oculocutaneous albinism, recurrent infections, and a propensity for bleeding. Oral health providers should be aware of the manifestations of individuals with CHS. Special care, including oral prophylaxis, is indispensable.

Evaluating Soft Tissue Healing after Implant Placement Using Two Different Mouthwashes (Myrrh and Chlorhexidine Gluconate): A Randomized Control Trial

The use of mouthwash is often recommended by dental experts for dental healing. A double-blind, randomized clinical study was conducted to evaluate the efficacy of two mouthwashes (myrrh and chlorhexidine gluconate) on postoperative pain and their effects on tissues after dental implant placement in 35 patients (18 in the myrrh group and 17 in the chlorhexidine gluconate group). Soft tissue healing was evaluated in terms of wound closure, soft tissue swelling, and the color of the gingiva at 1 week postoperative. To decrease the chances for error, only the participants who did not show preoperative symptoms of infection and those who committed to practicing better oral hygiene were included in the study. The samples were evaluated for the infiltration of inflammatory cells (using inflammatory extent and inflammatory cellularity grades), maturation of collagen (osteoblast activity), and arrangement of cells (for detecting the remodeling phase). A questionnaire pertaining to mouthwash satisfaction, the duration of postoperative pain after the procedure, the time of stoppage of bleeding at the surgical site, and any sensitivity at the surgical site was given to the patients. The Chi-square test and Mann–Whitney U-test were used to analyze the data. The difference in postoperative surgical swelling, pain, bleeding, and redness in the patients was not statistically significant between the myrrh and chlorhexidine gluconate mouthwash groups. However, in the acute phase, the myrrh mouthwash showed a positive impact on the process of wound healing after implant placement. The small sample size and inability to compare wound healing in different anatomical areas of the oral cavity were the study limitations.

Challenges in the Diagnosis and Treatment of Patients with Rare and Orphan Diseases

Orphan diseases are diverse group of disorders that have not gained much of public attention as they are rarely reported worldwide. The term orphan and rare diseases are often used interchangeably when describing diseases that fall into an orphan or rare category. Around 80% of orphan diseases are chronic, serious, or life threatening, are of genetic origin, and are more prevalent in children and in adults above 40 years of age. Due to rarity, lack of financial support and specific drug to treat these diseases, diagnosis, and treatment becomes challenging. Diagnosis is usually delayed, and patient continues to suffer by seeking multiple specialist opinion. Nonavailability of specific drug and lack of financial funding or waivers to conduct to conduct clinical trial for invention of new orphan drug are the obstacles for targeted treatment. Hence, there is need for comprehensive integrative approach to manage orphan disease patients and pharmaceutical companies should be encouraged for invention of drugs at a reasonable cost for orphan diseases. In addition, community education through genetic-based learning modules is essential to increase awareness of population about risk factors and early diagnosis of orphan diseases, and to take opinion of specific specialist for thorough clinical evaluation. This review discusses challenges faced by the specialists toward diagnosis and treatment of orphan disease for well-being of an individual living with the disorder.

Craniofacial tendon development-Characterization of extracellular matrix morphology and spatiotemporal protein distribution

Craniofacial (CF) tendons are often affected by traumatic injuries and painful disorders that can severely compromise critical jaw functions, such as mastication and talking. Unfortunately, tendons lack the ability to regenerate, and there are no solutions to restore their native properties or function. An understanding of jaw tendon development could inform tendon regeneration strategies to restore jaw function, however CF tendon development has been relatively unexplored. Using the chick embryo, we identified the jaw-closing Tendon of the musculus Adductor Mandibulae Externus (TmAM) and the jaw-opening Tendon of the musculus Depressor Mandibulae (TmDM) that have similar functions to the masticatory tendons in humans. Using histological and immunohistochemical (IHC) analyses, we characterized the TmAM and TmDM on the basis of cell and extracellular matrix (ECM) morphology and spatiotemporal protein distribution from early to late embryonic development. The TmAM and TmDM were detectable as early as embryonic day (d) 9 based on histological staining and tenascin-C (TNC) protein distribution. Collagen content increased and became more organized, cell density decreased, and cell nuclei elongated over time during development in both the TmAM and TmDM. The TmAM and TmDM exhibited similar spatiotemporal patterns for collagen type III (COL3), but differential spatiotemporal patterns for TNC, lysyl oxidase (LOX), and matrix metalloproteinases (MMPs). Our results demonstrate markers that play a role in limb tendon formation are also present in jaw tendons during embryonic development, implicate COL3, TNC, LOX, MMP2, and MMP9 in jaw tendon development, and suggest TmAM and TmDM possess different developmental programs. Taken together, our study suggests the chick embryo may be used as a model with which to study CF tendon extracellular matrix development, the results of which could ultimately inform therapeutic approaches for CF tendon injuries and disorders.

Rare Disorders: Diagnosis and Therapeutic Planning for Patients Seeking Orthodontic Treatment

The available literature on the orthodontic treatment of patients with rare disorders is extremely scarce. The aim of this study was to analyze the diagnosis and orthodontic treatment of a group of 94 individuals with rare diseases, referred for orthodontic evaluation to a university special care dentistry center (University of Santiago de Compostela, Spain). We created a control group of 94 systemically healthy individuals, paired by sex and age range. For all participants, we recorded their dental and skeletal abnormalities, oromotor dysfunctions and the characteristics of their orthodontic treatment. Some of the morphological and functional abnormalities were more prevalent in the rare disorders group than in the control group, including dental agenesis, microdontia, enamel defects, maxillary hypoplasia, overbite, cleft lip/palate, mouth breathing, atypical swallowing, lingual/labial interposition, labial incompetence, modified consistency diet, bruxism, and muscle tone abnormalities. Compared with the control group, the 56 patients with rare disorders who underwent orthodontic treatment required more desensitization sessions, used mixed appliances (fixed and removable) more often and for longer periods and had more frequent complications, such as gingivitis, caries, mucosal ulcers and recurrent debonding of the device. In conclusion, for selected patients with rare disorders, it is feasible to perform orthodontic treatment, whose planning will be determined by the dental-skeletal abnormalities and oromotor dysfunctions. Although complications are more frequent, they can typically be solved without having to stop treatment.

Spectrum of Genetic Diseases in Tunisia: Current Situation and Main Milestones Achieved

Genetic diseases in Tunisia are a real public health problem given their chronicity and the lack of knowledge concerning their prevalence and etiology, and the high rates of consanguinity. Hence, we performed systematic reviews of the literature in order to provide a more recent spectrum of these disorders and to expose the challenges that still exist to tackle these kinds of diseases. A manual textual data mining was conducted using MeSH and PubMed databases. Collected data were classified according to the CIM-10 classification and the transmission mode. The spectrum of these diseases is estimated to be 589 entities. This suggests remarkable progress through the development of biomedical health research activities and building capacities. Sixty percent of the reported disorders are autosomal recessive, which could be explained by the high prevalence of endogamous mating. Congenital malformations (29.54%) are the major disease group, followed by metabolic diseases (22%). Sixty percent of the genetic diseases have a known molecular etiology. We also reported additional cases of comorbidity that seem to be a common phenomenon in our population. We also noticed that epidemiological data are scarce. Newborn and carrier screening was only limited to pilot projects for a few genetic diseases. Collected data are being integrated into a database under construction that will be a valuable decision-making tool. This study provides the current situation of genetic diseases in Tunisia and highlights their particularities. Early detection of the disease is important to initiate critical intervention and to reduce morbidity and mortality.

Craniofacial Bone Tissue Engineering: Current Approaches and Potential Therapy

Craniofacial bone defects can result from various disorders, including congenital malformations, tumor resection, infection, severe trauma, and accidents. Successfully regenerating cranial defects is an integral step to restore craniofacial function. However, challenges managing and controlling new bone tissue formation remain. Current advances in tissue engineering and regenerative medicine use innovative techniques to address these challenges. The use of biomaterials, stromal cells, and growth factors have demonstrated promising outcomes in vitro and in vivo. Natural and synthetic bone grafts combined with Mesenchymal Stromal Cells (MSCs) and growth factors have shown encouraging results in regenerating critical-size cranial defects. One of prevalent growth factors is Bone Morphogenetic Protein-2 (BMP-2). BMP-2 is defined as a gold standard growth factor that enhances new bone formation in vitro and in vivo. Recently, emerging evidence suggested that Megakaryocytes (MKs), induced by Thrombopoietin (TPO), show an increase in osteoblast proliferation in vitro and bone mass in vivo. Furthermore, a co-culture study shows mature MKs enhance MSC survival rate while maintaining their phenotype. Therefore, MKs can provide an insight as a potential therapy offering a safe and effective approach to regenerating critical-size cranial defects.

Research algorithm for the detection of genetic patterns and phenotypic variety of non-syndromic dental agenesis

Introduction: Dental agenesis (DA), brings together the anodontia, oligodontia, hypodontia, characterized by a deficit in the development of a variable number of teeth. The objectives of the study were to illustrate the phenotypic variability of non-syndromic DA, to identify cases of DA with hereditary genetic transmission, and establish the mode of DA genetic pattern in these cases, together with the determination of DA prevalence in the population group study. Patients, Materials and Methods: The cross-sectional observational study was performed on a mixed population group, consisting of 861 Caucasian patients, between January 2018–December 2019. The clinical evaluation protocol of patients with DA, used to illustrate their phenotype, included the following stages: oral examination, photographic examination, and radiological examination. The evaluation protocol specific to the family genetic study of patients with DA, involved the following three stages: family survey, construction of the family tree and analysis of the pedigree structure. Results: The prevalence of DA in the population group was 2.78%. Regarding the phenotype, DA mainly affected the upper arch (50% of cases); bilateral DA had a significantly increased incidence (83.33% of cases) compared to unilateral form; in most cases (75%), a patient lacked one to two teeth, the lack of two teeth being the most common form (83.33% of cases); the upper lateral incisors were the teeth most frequently involved in DA (31.11% of the total missing teeth). Regarding the family genetic study, hereditary DA with autosomal dominant inheritance was present in 37.50% of cases. In the other cases (62.50%), isolated, sporadic forms of DA were registered, suggesting a spontaneous de novo mutation or a disorder of odontogenesis of a non-genetic nature. Conclusions: We consider that this study is of interest for current scientific research with applicability in dental medicine, by bringing actual information on the prevalence of non-syndromic DA in South-East Romania, the variety of phenotypic spectrum of DA for this geographic area, and the role of heredity in the DA genetic determinism in the studied population.

Knowledge and Associated Factors about Rare Diseases among Dentists in Israel: A Cross Sectional Survey

Aim: The current study aims to assess levels of knowledge among Israeli dentists about rare diseases with orofacial manifestations, and whether occupational, regional and social factors influence those levels. Materials and Methods: A total of 309 Israeli dentists participated in an online survey that provided basic demographic information pertaining to their knowledge about rare diseases, their clinical experience with rare diseases, what further information they considered necessary, and which sources of information they most frequently utilize. Results: Young age, country of dental education, practicing in both public and private settings, as well as the number of hours allocated to dental studies and the opportunity to acquire information on rare diseases with orofacial manifestations, all seem to affect the level of knowledge. Conclusions: Developments in the field of rare disease are constantly ongoing, and improvements in post-graduate dental studies about them should keep pace. The results of the current study reveal the areas upon which such curricula should focus with respect to dental practitioners.

Phenotype and Surgical Treatment in a Case of Proteus Syndrome With Craniofacial and Oral Findings

BACKGROUND/AIM

Proteus syndrome is a sporadic disease that is particularly noticeable due to the disproportional growth of body segments. The disease is a genetic mosaic. The mutations can arise from any of the germ layers, an explanation of the very variable phenotype. The aim of this report is to communicate the diagnosis and management of an unusual case of Proteus Syndrome with special attention to oral and craniofacial findings.

CASE REPORT

A 15-year-old patient was referred for surgical treatment of pronounced skull malformations and correction of oral mucosal hyperplasia. Treatment caused significant improvement in facial appearance and oral soft tissue conditions.

CONCLUSION

Surgical measures adapted to the local findings and symptoms can often relieve severe disfigurement of the patient.

Identification of the novel SDR42E1 gene that affects steroid biosynthesis associated with the oculocutaneous genital syndrome

Hereditary connective tissue diseases form a heterogeneous group of disorders that affect collagen and extracellular matrix components. The cornea and the skin are among the major forms of connective tissues, and syndromes affecting both organs are often due to mutations in single genes. Brittle cornea syndrome is one of the pathologies that illustrates this association well. Furthermore, sex hormones are known to play a role in the maintenance of the structure and the integrity of the connective tissue including the skin and cornea, and may be involved in pathogenesis of oculocutaneous diseases. Herein, a double consanguineous family of Moroccan origin with two affected siblings, with suspected brittle cornea syndrome, was recruited. Ophthalmic examinations and genetic testing were performed in all the nuclear family individuals. Clinical examinations showed that the two affected boys presented with thinning of the cornea, blue sclera, keratoconus, hyperelasticity of the skin, joint hypermobility, muscle weakness, hearing loss and dental abnormalities that are compatible with the diagnosis of BCS disease. They showed however additional clinical signs including micropenis, hypospadias and cryptorchidism, suggesting abnormalities in endocrine pathways. Using a duo exome sequencing analysis performed in the mother and the propositus, we identified the novel homozygous missense mutation c.461G > A (p.Arg154Gln) in the short-chain dehydrogenase/reductase family 42E member 1 (SDR42E1) gene. This novel mutation, which co-segregated with the disease in the family, was predicted to be pathogenic by bioinformatics tools. SDR42E1 stability analysis using DynaMut web-server showed that the p.Arg154Gln mutations has a destabilizing effect with a ΔΔG value of -1.039 kcal/mol. As this novel gene belongs to the large family of short-chain dehydrogenases/reductases (SDR) thought to be involved in steroid biosynthesis, endocrinological investigations subsequently revealed that the two patients also had low levels of cholesterol. Karyotyping revealed a normal 46,XY karyotype for the two boys, excluding other causes of disorders of sex development due to chromosomal rearrangements. In conclusion, our study reveals that mutation in the novel SDR42E1 gene alters the steroid hormone synthesis and associated with a new syndrome we named oculocutaneous genital syndrome. In addition, this study highlights the role of SDR42E1 in the regulation of cholesterol metabolism in the maintenance of connective tissue and sexual maturation in humans.

Dental Pulp-Derived Mesenchymal Stem Cells for Modeling Genetic Disorders

A subpopulation of mesenchymal stem cells, developmentally derived from multipotent neural crest cells that form multiple facial tissues, resides within the dental pulp of human teeth. These stem cells show high proliferative capacity in vitro and are multipotent, including adipogenic, myogenic, osteogenic, chondrogenic, and neurogenic potential. Teeth containing viable cells are harvested via minimally invasive procedures, based on various clinical diagnoses, but then usually discarded as medical waste, indicating the relatively low ethical considerations to reuse these cells for medical applications. Previous studies have demonstrated that stem cells derived from healthy subjects are an excellent source for cell-based medicine, tissue regeneration, and bioengineering. Furthermore, stem cells donated by patients affected by genetic disorders can serve as in vitro models of disease-specific genetic variants, indicating additional applications of these stem cells with high plasticity. This review discusses the benefits, limitations, and perspectives of patient-derived dental pulp stem cells as alternatives that may complement other excellent, yet incomplete stem cell models, such as induced pluripotent stem cells, together with our recent data.

Tough magnesium phosphate-based 3D-printed implants induce bone regeneration in an equine defect model

One of the important challenges in bone tissue engineering is the development of biodegradable bone substitutes with appropriate mechanical and biological properties for the treatment of larger defects and those with complex shapes. Recently, magnesium phosphate (MgP) doped with biologically active ions like strontium (Sr²⁺) have shown to significantly enhance bone formation when compared with the standard calcium phosphate-based ceramics. However, such materials can hardly be shaped into large and complex geometries and more importantly lack the adequate mechanical properties for the treatment of load-bearing bone defects. In this study, we have fabricated bone implants through extrusion assisted three-dimensional (3D) printing of MgP ceramics modified with Sr²⁺ ions (MgPSr) and a medical-grade polycaprolactone (PCL) polymer phase. MgPSr with 30 wt% PCL (MgPSr-PCL30) allowed the printability of relevant size structures (>780 mm³) at room temperature with an interconnected macroporosity of approximately 40%. The printing resulted in implants with a compressive strength of 4.3 MPa, which were able to support up to 50 cycles of loading without plastic deformation. Notably, MgPSr-PCL30 scaffolds were able to promote in vitro bone formation in medium without the supplementation with osteo-inducing components. In addition, long-term in vivo performance of the 3D printed scaffolds was investigated in an equine tuber coxae model over 6 months. The micro-CT and histological analysis showed that implantation of MgPSr-PCL30 induced bone regeneration, while no bone formation was observed in the empty defects. Overall, the novel polymer-modified MgP ceramic material and extrusion-based 3D printing process presented here greatly improved the shape ability and load-bearing properties of MgP-based ceramics with simultaneous induction of new bone formation.