Morphology of pulpal mineralizations: A scoping review.

OBJECTIVE: The aim of this scoping review was to summarize and discuss the morphological features and associated factors of pulpal mineralizations (PMs) as described within the literature. DATA: The study protocol was registered on the Open Science Framework platform and is available at the following link: https://osf.io/hfqwe. This scoping review was developed according to the PRISMA-ScR guidelines. SOURCES: A literature search of four electronic databases was performed in SCOPUS, MEDLINE (PubMed), EMBASE and Word of Science, with the last search on May 29, 2023. Study selection was completed by two reviewers independently. Data was extracted regarding study characteristics, types, and features of PM and associated factors. STUDY SELECTION: Of 1016 studies initially identified ten which qualified were included in this scoping review. Systemic and local factors that result in pulpal insult can contribute to the development of PMs. Three forms of PM have been reported, pulp stones, diffuse mineralizations, and mineralized ectopic connective tissue, with discrete and diffuse mineralization being the two clinically relevant forms. The different forms of PMs exhibit dissimilar morphological features. CONCLUSION: Pulpal mineralizations exist in two clinically relevant forms: diffuse and discrete mineralizations and are likely associated with a pulpal insult. CLINICAL SIGNIFICANCE: Understanding the morphology of dental pulp mineralization is the first step to expanding the knowledge of pulp mineralization and could result in improved diagnosis of endodontic pathosis.

Relationship between skeletal maturity indicators and dental calcification stages in a sample pediatric population.

Context: Human growth shows considerable variation. In addition to constitutional differences in the timing of maturation, there are diseases, systemic disorders and environmental factors that may affect a child's physiologic maturity. Interrelationships among skeletal, somatic and sexual maturity have been shown to be consistently strong. The study was conducted to evaluate the relationship between dental calcification stages and skeletal maturity indicators. Materials and Methods: The hand wrist radiographs, the lateral cephalogram and the orthopantomogram (OPG) of 120 patients (60 males and 60 females, age group 8-14 years) were taken. The hand wrist radiographs were analyzed using Fishman's skeletal maturity index (SMI), and the cephalograms analyzed by cervical vertebrae maturation (CVM) by Baccetti. OPG was analyzed according to the Demirjian's system. Result: On assessment, cervical vertebrae maturation indicator (CVMI) staging showed significant results with a correlation coefficient of 0.716 being the highest in canines in males while assessment of dental calcification stages and its comparison with skeletal maturity indicator showed insignificant results. The correlation coefficient values were 0.11, 0.09, 0.09 and 0.13 for canine, first premolar, second premolar and second molar respectively. Conclusion: There is a strong correlation between the maturation stage of cervical vertebrae and calcification stages of canine, first premolar, second premolar and second molar as determined by Demirjian's method.

[Retrospective evaluation of treatment outcomes in immature teeth treated with regenerative endodontic procedures with an over-36-month review].

OBJECTIVE: To evaluate the clinical outcomes of immature teeth treated with regenerative endodontic procedures with an over-36-month review, to identify potential contributing factors of root deve-lopment, and to provide new reference for long-time prognosis of regenerative endodontic procedures. METHODS: We recruited teeth that had undergone regenerative endodontic procedures at the Department of Pediatric Dentistry in Peking University School and Hospital of Stomatology from January 2013 to June 2017 and had a follow-up period of more than 36 months.Clinical and radiographic records were collected.We evaluated the treatment outcomes and summarized different patterns of root development.Changes in root length, root canal wall thickness were compared between preoperative and recall radiographs.A statistical analysis was performed using software SPSS 22.0 to identify potential contributing factors of root development. RESULTS: In this study, 84 teeth were recruited and the mean follow-up period was (44.7±19.3) months.The longest follow-up period was 81 months.Sixty-eight teeth (81.0%) were clinical success with bony healing, and 55 teeth (80.9%) gained the continued root development.Forty teeth completed root development with apical closure.The rate of the apical closure reached 58.8%.Twenty-four teeth gained normal root morphology with the increasing of root length and canal wall thickness and apical closure.The rate of continued root development was 92.5% in teeth with broken central cusp and 58.3% in teeth with trauma, which was statistically significant (P < 0.05).There was a statistically significant difference (P < 0.05) between the root development rates of teeth with different induced bleeding heights (orifice/middle/tip of the root)(92.9%/81.0%/63.2%). CONCLUSION: Most of the teeth treated with regenerative endodontic procedures achieved continued root development with an over 36-month follow-up.However, the patterns of root development were different.The morphology of some teeth were close to the physiological state.Etiology and the height of induced bleeding are two factors significantly associated with the rate of the continued development root.

Novel Genetic Determinants of Dental Maturation in Children.

Dental occlusion requires harmonious development of teeth, jaws, and other elements of the craniofacial complex, which are regulated by environmental and genetic factors. We performed the first genome-wide association study (GWAS) on dental development (DD) using the Demirjian radiographic method. Radiographic assessments from participants of the Generation R Study (primary study population, N1 = 2,793; mean age of 9.8 y) were correlated with ~30 million genetic variants while adjusting for age, sex, and genomic principal components (proxy for population stratification). Variants associated with DD at genome-wide significant level (P < 5 × 10-8) mapped to 16q12.2 (IRX5) (lead variant rs3922616, B = 0.16; P = 2.2 × 10-8). We used Fisher's combined probability tests weighted by sample size to perform a meta-analysis (N = 14,805) combining radiographic DD at a mean age of 9.8 y from Generation R with data from a previous GWAS (N2 = 12,012) on number of teeth (NT) in infants used as proxy of DD at a mean age of 9.8 y (including the ALSPAC and NFBC1966). This GWAS meta-analysis revealed 3 novel loci mapping to 7p15.3 (IGF2BP3: P = 3.2 × 10-8), 14q13.3 (PAX9: P = 1.9 × 10-8), and 16q12.2 (IRX5: P = 1.2 × 10-9) and validated 8 previously reported NT loci. A polygenic allele score constructed from these 11 loci was associated with radiographic DD in an independent Generation R set of children (N = 703; B = 0.05, P = 0.004). Furthermore, profiling of the identified genes across an atlas of murine and human stem cells observed expression in the cells involved in the formation of bone and/or dental tissues (>0.3 frequency per kilobase of transcript per million mapped reads), likely reflecting functional specialization. Our findings provide biological insight into the polygenic architecture of the pediatric dental maturation process.

Age estimation of individuals aged 5-23 years based on dental development of the Indonesian population.

Dental development can be used to estimate age for forensic purposes. However, most of the currently available methods are less reliable for the Indonesian population due to population variability. This study presents a new method and evaluates other methods that utilize dental development to estimate the age of Indonesian people. Panoramic radiographs of 304 young Indonesian people aged 5-23 years old were analysed for deciduous tooth root resorption, permanent tooth calcification, and eruption. The extent of tooth root resorption was determined based on AlQahtani's modified Moorrees et al. method. Tooth calcification was classified based on a modified Demirjian et al. method. Tooth eruption was evaluated based on AlQahtani's modified Bengston system. The sequence of tooth root resorption, and permanent tooth calcification and eruption were grouped into 19 age categories (from 5-23 years old) in an atlas. The differences between males and females, between maxillary and mandibular teeth, and between right and left teeth were also analysed. There were minimal significant differences of tooth development between males and females, and between the right and left teeth (P > 0.05), while the maxillary and mandibular dental development was significantly different (P < 0.05). The newly developed atlas showed the development of the right side of maxillary and mandibular tooth of combined sex of Indonesian population. Another 34 panoramic radiographs of known-age and sex individuals from Indonesia were assessed using the newly developed Atlas of Dental Development in the Indonesian Population, Ubelaker's Dental Development Chart, The London Atlas of Human Tooth Development and Eruption by AlQahtani, and the Age Estimation Guide-Modern Australia population by Blenkin-Taylor. Accuracy was assessed by comparing estimated age to actual chronological age using the Bland-Altmand test. Results show that the smallest range of error was found in the Atlas of Dental Development in the Indonesian Population (-0.969 to 1.210 years), followed by The London Atlas of Human Tooth Development and Eruption by AlQahtani (-2.013 to 1.990 years), the Age Estimation Guide-Modern Australia population by Blenkin-Taylor (-2.495 to 2.598 years), and the Dental Development Chart by Ubelaker (-2.960 to 3.289 years). These findings show that the Atlas of Dental Development constructed in this study performs better than the other three methods and presents greater accuracy of age estimation in the Indonesian population.Key pointsDental development such as deciduous tooth root resorption, permanent tooth calcification, and tooth eruption can be used to estimate age for forensic purposes.The development of the teeth are influenced by genetic, ethnicity, and sex, therefore an age estimation method must be constructed based on the same population.There were minimal significant differences in tooth development between male and female, and between right and left teeth, but there was significant difference between maxillary and mandibular teeth.The Atlas of Dental Development in the Indonesian Population constructed in this study allowed more accurate age estimation of the Indonesian sample than the other methods tested. Supplemental data for this article are available online at https://doi.org/10.1080/20961790.2021.1886648.

Dental and Endodontic Management in a Patient with Familial X-Linked Hypophosphatemic Rickets

ABSTRACT: The term rickets refers to insufficient or retarded mineralization of the osteoide matrix. X-linked hypophosphatemic (XLH) rickets is a rare genetic disorder characterized by biochemical changes in bone mineralization due to inactivation of the phosphate regulating gene and primary defect of the osteoblasts. The aim of this article was to report a clinical case of XLH, its oral manifestations, periapical changes and dental management. A 31-year old woman female patient was referred to the school of dentistry with pain and sensitivity in the teeth. She had a childhood history of rickets, hypophosphatemia and alteration in Vitamin D. In the oral exam, enamel hypoplasia, microdontia, fistula, caries and periapical lesions and periodontal disease were diagnosed. The radiographic and tomographic exams exhibited the presence of periapical lesions involving various teeth with radiolucent images, suggestive of granuloma or periapical cysts. The treatme nt prioritized the urgency of eliminating pain and removing the foci of infection. Endodontic treatment began in the teeth that had fistula or periapical lesions and in parallel, oral hygiene guidance was provided and periodontal treatment was performed. There was an improvement in the clinical condition with reduction in inflammation and mobility of the teeth. Dentists and health professionals must evaluate the patient as a whole, considering the relations between systemic and oral health. Knowledge of systemic diseases associated with rickets and their characteristics is essential for making a correct oral diagnosis and planning the dental treatment.

RESUMEN: El término raquitismo se refiere a la mineralización insuficiente o retardada de la matriz osteoide. El raquitismo hipofosfatémico ligado al cromosoma X (XLH) es un trastorno genético caracterizado por cambios bioquímicos en la mineralización ósea debido a la inactivación del gen regulador del fosfato y al defecto primario de los osteoblastos. El objetivo de este artículo fue reportar un caso clínico de XLH, sus manifestaciones orales, cambios periapicales y manejo dental. La paciente, una mujer de 31 años, acudió a la Clínica de Semiología de la UFPR con dolor y sensibilidad en varios dientes. Tenía antecedentes infantiles de raquitismo, hipofosfatemia y alteración de la vitamina D. En el examen oral se diagnosticó hipoplasia del esmalte, microdoontia, fístula, caries y lesiones periapicales y enfermedad periodontal. Los exámenes radiográficos y tomográficos mostraron la presencia de lesiones periapicales en varios dientes con imágenes radiolúcidas, sugestivas de granuloma o quistes periapicales. El tratamiento priorizó la urgencia de eliminar el dolor y remover los focos de infección. Se inició tratamiento de endodoncia en los dientes que presentaban fístula o lesiones periapicales y paralelamente se brindó orientación de higiene oral y se realizó tratamiento periodontal. Hubo una mejoría en la condición clínica con reducción de la inflamación y movilidad de los dientes. Los odontólogos y profesionales de la salud deben evaluar al paciente como un todo, teniendo en cuenta las relaciones entre salud sistémica y oral. El conocimiento de las enfermedades sistémicas asociadas al raquitismo y sus características es fundamental para realizar un correcto diagnóstico oral y planificar el tratamiento odontológico.

Successful management of a tooth with canal obstruction using "cold ceramic".

One of the causes of treatment failure is calcification in the canal pathway, which prevents complete access to proper working length, and one of the most difficult and challenging cases of root canal treatment has been reported. In some cases, the dentist will not be able to open the calcified canal. Therefore, the prognosis of root canal treatment in these cases has been reported poor, and the dentist will offer a plan for possible treatments, including tooth extraction or apical surgery. The presented case is one example of those cases with a periapical lesion, which as a temporary treatment, the pulp chamber was filled with cold ceramic. This material, which is an MTA-like (Mineral Trioxide Aggregate) bioceramic with proper sealing ability, has been introduced as a root-end filling material. After 6 years of which the patient returned, he did not express any pain or discomfort during these 6 years. Furthermore, in radiograph that was taken, periapical lesion relative healing and bone regeneration were amazingly seen.

Assessment of the Relationship between Skeletal Maturity and the Calcifications Stages of Permanent Canines and Second Premolars.

OBJECTIVE: This study aimed to evaluate the relationship between the calcification stages of permanent maxillary and mandibular canines and second premolars and skeletal maturity in both sexes. METHODS: This study included 138 patients (82 females, 56 males) who were treated in the Department of Orthodontics, Altinbas University. The mean age of the patients was 12.31±1.76 years, ranging from 7.8 years to 15.8 years. Dental maturity stages of canines and second premolars were evaluated according to the Demirjian index on digital panoramic radiograph. The skeletal maturation stage was determined using the cervical vertebral maturation (CVM) index. The Pearson correlation analysis was performed to assess the association among CVM stages and calcification stages of canines, second premolars, sex, and chronological ages. RESULTS: A statistically significant correlation was found between CVM and the calcification stages of the canines and second premolars (p<0.05). The calcification stages of the canines and second premolars had the highest distribution of Stage F and Stage G at CVM2 (p<0.01). For the canines and second premolars, Stage H corresponded to CVM3 in female patients and a high percentage of Stage G corresponded to CVM3 in the male group. CONCLUSION: A significant correlation was found between the calcification stages of maxillary and mandibular canines, second premolars, and skeletal maturity in both sexes. It was observed that calcification stages and cervical maturations were advanced in female subjects compared with male subjects.

Calcificaciones pulpares en pacientes con diabetes mellitus / Pulp calcifications in patients with diabetes mellitus

RESUMEN Introducción: Las células de la pulpa dental tienen la capacidad, ante estímulos locales y sistémicos, de activar a la osteopontina, formando calcificaciones pulpares, bloqueando los conductos radiculares y modificando la anatomía interna; de manera que se intensifican en personas con diabetes mellitus. Objetivo: Determinar si existe mayor presencia de calcificaciones a nivel de cámara pulpar en pacientes con diabetes mellitus versus pacientes sin diabetes mellitus. Métodos: Se realizó un estudio de casos y controles, analítico, transversal y retrospectivo. Se utilizaron los registros clínicos y las radiografías digitales periapicales de pacientes de las clínicas odontológicas de pregrado (Prótesis, Restauradora, Integral, Periodoncia) y de postgrado (Periodoncia e Implantología quirúrgica) de la Universidad Andrés Bello - Chile, entre los años 2017 y 2018. Se seleccionó una muestra de 617 dientes (45 pacientes) luego de ser aplicados los criterios de exclusión e inclusión en la base de datos clínica. La muestra completó dos grupos, grupo de casos (22 pacientes): dientes de pacientes con diabetes mellitus 228 dientes indemnes y el grupo de control (23 pacientes): dientes de pacientes sin diabetes mellitus 389 dientes indemnes. Se realizó una calibración previa entre los investigadores para la identificación y clasificación de calcificaciones pulpares durante el análisis radiográfico de estas. Se realizaron inferencias estadísticas de chi cuadrado para establecer significación de los resultados obtenidos. Resultados: Los dientes de 22 pacientes diabéticos presentaron más calcificaciones camerales que los dientes de 23 pacientes no diabéticos, para 50 por ciento de dientes calcificados en pacientes diabéticos (n=114) y 26 por ciento en pacientes no diabéticos (n=101); este resultado fue estadísticamente significativo (pvalor< 0,001). Conclusiones: Los pacientes con diabetes mellitus demostraron que son más propensos a formar calcificaciones camerales debido al aumento de glucosa presente en la sangre que activa a la osteopontina(AU)

ABSTRACT Introduction: Dental pulp cells have the capacity to respond to local and systemic stimuli by activating osteopontin, forming pulp calcifications, blocking root canals and modifying internal anatomy, in such a way that they intensify in people with diabetes mellitus. Objective: Determine whether there is a greater presence of calcifications in the pulp chamber of patients with diabetes mellitus vs. patients without diabetes mellitus. Methods: An analytical cross-sectional retrospective case-control study was conducted of medical records and digital periapical radiographs of patients attending undergraduate dental clinics (prosthesis, restoration, comprehensive, periodontics) and graduate dental clinics (periodontics and surgical implantology) of Andrés Bello University, Chile, in the period 2017-2018. A sample was selected of 617 teeth (45 patients) from the clinical database upon applying exclusion and inclusion criteria. The sample was divided into two groups: a case group, formed by 228 undamaged teeth from 22 patients with diabetes mellitus, and a control group, formed by 389 undamaged teeth from 23 patients without diabetes mellitus. Prior calibration was performed by the researchers to identify and classify the pulp calcifications during their radiographic analysis. Chi-squared statistical inferences were made to establish the significance of the results obtained. Results: The teeth from the 22 diabetic patients had more chamber calcifications than the teeth from the 23 nondiabetic patients, for 50 percent calcified teeth in diabetic patients (n= 114) and 26 percent in nondiabetic patients (n= 101). This result was statistically significant (p-value< 0.001). Conclusions: Patients with diabetes mellitus were found to be more prone to form chamber calcifications, due to the increase in glucose present in the blood which activates osteopontin(AU)

Reduced Orthodontic Tooth Movement in Enpp1 Mutant Mice with Hypercementosis.

Previous studies revealed that cementum formation is tightly regulated by inorganic pyrophosphate (PPi), a mineralization inhibitor. Local PPi concentrations are determined by regulators, including ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), which increases PPi concentrations by adenosine triphosphate hydrolysis. Orthodontic forces stimulate alveolar bone remodelling, leading to orthodontic tooth movement (OTM). To better understand how disturbed mineral metabolism and the resulting altered periodontal structures affect OTM, we employed Enpp1 mutant mice that feature reduced PPi and increased cervical cementum in a model of OTM induced by a stretched closed-coil spring ligated between the maxillary left first molar and maxillary incisors. We analyzed tooth movement, osteoclast/odontoclast response, and tooth root resorption by micro-computed tomography, histology, histomorphometry, and immunohistochemistry. Preoperatively, we noted an altered periodontium in Enpp1 mutant mice, with significantly increased periodontal ligament (PDL) volume and thickness, as well as increased PDL-bone/tooth root surface area, compared to wild-type (WT) controls. After 11 d of orthodontic treatment, Enpp1 mutant mice displayed 38% reduced tooth movement versus WT mice. Molar roots in Enpp1 mutant mice exhibited less change in PDL width in compression and tension zones compared to WT mice. Root resorption was noted in both groups with no difference in average depths, but resorption lacunae in Enpp1 mutant mice were almost entirely limited to cementum, with 150% increased cementum resorption and 92% decreased dentin resorption. Osteoclast/odontoclast cells were reduced by 64% in Enpp1 mutant mice, with a predominance of tartrate-resistant acid phosphatase (TRAP)-positive cells on root surfaces, compared to WT mice. Increased numbers of TRAP-positive cells on root surfaces were associated with robust immunolocalization of osteopontin (OPN) and receptor-activator of NF-κB ligand (RANKL). Collectively, reduced response to orthodontic forces, decreased tooth movement, and altered osteoclast/odontoclast distribution suggests Enpp1 loss of function has direct effects on clastic function/recruitment and/or indirect effects on periodontal remodeling via altered periodontal structure or tissue mineralization.

Validity and accuracy of three radiographic dental age estimation methods in Brazilians.

OBJECTIVE: To validate, analyse accuracy, and construct multiple regression formulae of three age estimation methods - Liliequist and Lundberg, Haavikko, and Mornstad - using mineralization stages of permanent teeth in Brazilians. METHODS: Panoramic radiographs of 1009 Brazilian children and adolescents (387 males and 622 females) aged 8-15.99 years were analysed using the aforementioned methodologies. RESULTS: The overall accuracy (absolute difference=AD and dental age-chronological age=DA-CA) of the methods was as follows: Liliequist and Lundberg, AD=0.97 and DA-CA=-0.58; Haavikko, AD=1.42 and DA-CA=-1.35; and Mornstad, AD=2.48 and DA-CA=0.78. After sex-based stratification, the values for males were as follows: Liliequist and Lundberg, AD=0.91 and DA-CA=-0.45; Haavikko, AD=1.80 and DA-CA=-1.75; and Mornstad, AD=2.74 and DA-CA=1.17. In females, the values were as follows: Liliequist and Lundberg, DA=1.01 and DA-CA=-0.67; Haavikko, AD=1.17 and DA-CA=-1.09; and Mornstad, AD=2.31 and DA-CA=0.53. The Liliequist and Lundberg technique predominated, followed by Haavikko and Mornstad when distinction was present between sex and age. Multiple regression formulae were constructed from the data presented for the Liliequist and Lundberg, Haavikko and Mornstad methodologies. CONCLUSIONS: The validation of the methodologies in the Brazilian population is possible. The Liliequist and Lundberg method most closely represented the Brazilian sample.

Expression of Phosphate Transporters during Dental Mineralization.

The importance of phosphate (Pi) as an essential component of hydroxyapatite crystals suggests a key role for membrane proteins controlling Pi uptake during mineralization in the tooth. To clarify the involvement of the currently known Pi transporters (Slc17a1, Slc34a1, Slc34a2, Slc34a3, Slc20a1, Slc20a2, and Xpr1) during tooth development and mineralization, we determined their spatiotemporal expression in murine tooth germs from embryonic day 14.5 to postnatal day 15 and in human dental samples from Nolla stages 6 to 9. Using real-time polymerase chain reaction, in situ hybridization, immunohistochemistry, and X-gal staining, we showed that the expression of Slc17a1, Slc34a1, and Slc34a3 in tooth germs from C57BL/6 mice were very low. In contrast, Slc34a2, Slc20a1, Slc20a2, and Xpr1 were highly expressed, mostly during the postnatal stages. The expression of Slc20a2 was 2- to 10-fold higher than the other transporters. Comparable results were obtained in human tooth germs. In mice, Slc34a2 and Slc20a1 were predominantly expressed in ameloblasts but not odontoblasts, while Slc20a2 was detected neither in ameloblasts nor in odontoblasts. Rather, Slc20a2 was highly expressed in the stratum intermedium and the subodontoblastic cell layer. Although Slc20a2 knockout mice did not show enamel defects, mutant mice showed a disrupted dentin mineralization, displaying unmerged calcospherites at the mineralization front. This latter phenotypical finding raises the possibility that Slc20a2 may play an indirect role in regulating the extracellular Pi availability for mineralizing cells rather than a direct role in mediating Pi transport through mineralizing plasma cell membranes. By documenting the spatiotemporal expression of Pi transporters in the tooth, our data support the possibility that the currently known Pi transporters may be dispensable for the initiation of dental mineralization and may rather be involved later during the tooth mineralization scheme.

Overlapping functions of bone sialoprotein and pyrophosphate regulators in directing cementogenesis.

Although acellular cementum is essential for tooth attachment, factors directing its development and regeneration remain poorly understood. Inorganic pyrophosphate (PPi), a mineralization inhibitor, is a key regulator of cementum formation: tissue-nonspecific alkaline phosphatase (Alpl/TNAP) null mice (increased PPi) feature deficient cementum, while progressive ankylosis protein (Ank/ANK) null mice (decreased PPi) feature increased cementum. Bone sialoprotein (Bsp/BSP) and osteopontin (Spp1/OPN) are multifunctional extracellular matrix components of cementum proposed to have direct and indirect effects on cell activities and mineralization. Studies on dentoalveolar development of Bsp knockout (Bsp-/-) mice revealed severely reduced acellular cementum, however underlying mechanisms remain unclear. The similarity in defective cementum phenotypes between Bsp-/- mice and Alpl-/- mice (the latter featuring elevated PPi and OPN), prompted us to examine whether BSP is operating by modulating PPi-associated genes. Genetic ablation of Bsp caused a 2-fold increase in circulating PPi, altered mRNA expression of Alpl, Spp1, and Ank, and increased OPN protein in the periodontia. Generation of a Bsp knock-out (KO) cementoblast cell line revealed significantly decreased mineralization capacity, 50% increased PPi in culture media, and increased Spp1 and Ank mRNA expression. While addition of 2µg/ml recombinant BSP altered Spp1, Ank, and Enpp1 expression in cementoblasts, changes resulting from this dose were not dependent on the integrin-binding RGD motif or MAPK/ERK signaling pathway. Decreasing PPi by genetic ablation of Ank on the Bsp-/- mouse background reestablished cementum formation, allowing >3-fold increased acellular cementum volume compared to wild-type (WT). However, deleting Ank did not fully compensate for the absence of BSP. Bsp-/-; Ank-/- double-deficient mice exhibited mean 20-27% reduced cementum thickness and volume compared to Ank-/- mice. From these data, we conclude that the perturbations in PPi metabolism are not solely driving the cementum pathology in Bsp-/- mice, and that PPi is more potent than BSP as a cementum regulator, as shown by the ability to override loss of BSP by lowering PPi. We propose that BSP and PPi work in concert to direct mineralization in cementum and likely other mineralized tissues.

A comparative evaluation of dental calcification stages and skeletal maturity indicators in North-Indian children.

BACKGROUND: Many researchers have reported relationships between the calcification stages of individual teeth and skeletal maturity. A few studies are available in the literature about Indian populations. In view of this fact, this study was conducted to investigate the relationship between the dental calcification stages and skeletal maturity stages among North-Indian individuals. The objective of this study was to determine whether dental calcification can be used as a first-level diagnostic tool for assessment of skeletal maturity. MATERIALS AND METHODS: The study participants included (60 males, 60 females) ranging from 7 to 13 years. A total of 120 dental panoramic radiographs and hand-wrist radiographs were obtained and analyzed. Calcification stages of the mandibular dentition (canines, first premolars, second premolars, and second molars) were rated according to the system of Demirjian et al. Skeletal maturity indicators stages were determined using the Fishman method. RESULTS AND CONCLUSION: Bivarate correlation ranged from 0.58 to 0.75 for males and 0.73 to 0.84 for females. Canine showed the highest correlation in males and second molar showed the highest correlation in females. Canine calcification Stage H represent prepeak of the pubertal growth spurt in male patients. Calcification Stage G for second molar represents the prepeak and Stage H represents the peak of pubertal growth spurt in females.

Relationship between dental calcification and skeletal maturation in a Peruvian sample

ABSTRACT Objective: the objective of the study was to determine the relationship between dental calcification stages and skeletal maturation in a Peruvian sample. Methods: panoramic, cephalometric and carpal radiographs of 78 patients (34 girls and 44 boys) between 7 and 17 years old (9.90 ± 2.5 years) were evaluated. Stages of tooth calcification of the mandibular canine, first premolar, second premolar, and second molar and the skeletal maturation with a hand-wrist and a cervical vertebrae method were assessed. The relationships between the stages were assessed using Spearman's correlation coefficient. Additionally, the associations of mandibular and pubertal growth peak stages with tooth calcification were evaluated by Fisher's exact test. Results: all teeth showed positive and statistically significant correlations, the highest correlation was between the mandibular second molar calcification stages with hand-wrist maturation stages (r = 0.758, p < 0.001) and with vertebrae cervical maturation stages (r = 0.605, p < 0.001). The pubertal growth spurt was found in the G stage of calcification of the second mandibular molar, and the mandibular growth peak was found in the F stage of calcification of the second molar. Conclusion: there was a positive relationship between dental calcification stages and skeletal maturation stages by hand-wrist and cervical vertebrae methods in the sample studied. Dental calcification stages of the second mandibular molar showed the highest positive correlation with the hand-wrist and cervical vertebrae stages.

RESUMO Objetivo: o objetivo do presente estudo foi determinar a correlação entre o estágio de calcificação dentária e a maturação esquelética, em uma amostra de indivíduos peruanos. Métodos: radiografias panorâmicas, cefalométricas e carpais de 78 pacientes (34 meninas e 44 meninos) com idades entre 7 e 17 anos (média = 9,90 ± 2,5 anos) foram avaliadas. Nelas, avaliaram-se os estágios de calcificação dentária (canino, primeiro pré-molar, segundo pré-molar e segundo molar inferiores) e de maturação esquelética, pelas avaliações radiográficas da mão e punho e das vértebras cervicais. As correlações entre esses estágios foram avaliadas usando-se o coeficiente de correlação de Spearman. Adicionalmente, a associação entre os estágios em que ocorreram os picos de crescimento mandibular e de crescimento puberal e o grau de calcificação dentária foi avaliada pelo teste exato de Fisher. Resultados: todos os dentes demonstraram correlações positivas e estatisticamente significativas. A correlação mais elevada foi verificada entre o estágio de calcificação do segundo molar inferior e o estágio de maturação esquelética da mão e do punho (r= 0,758, p < 0,001) e o estágio de maturação das vértebras cervicais (r = 0,605, p < 0,001). O surto de crescimento puberal foi identificado no estágio G de calcificação do segundo molar inferior, e o pico de crescimento mandibular foi detectado no estágio F de calcificação do segundo molar. Conclusão: na amostra estudada, houve uma correlação positiva entre os estágios de calcificação dentária e os estágios de maturação esquelética avaliada nas radiografias de mão e punho e das vértebras cervicais. Os estágios de calcificação dentária do segundo molar inferior demonstraram a mais alta correlação positiva com os estágios de maturação da mão e punho e das vértebras cervicais.

Correlation between Cervical Vertebral Maturation Stages and Dental Maturation in a Saudi Sample.

BACKGROUND: The aim of the present study was to compare the cervical vertebra maturation stages method and dental maturity using tooth calcification stages. METHODS: The current study comprised of 405 subjects selected from orthodontic patients of Saudi origin coming to clinics of the specialized dental centers in western region of Saudi Arabia. Dental age was assessed according to the developmental stages of upper and lower third molars and skeletal maturation according to the cervical vertebrae maturation stage method. Statistical analysis was done using Kruskal-Wallis H, Mann-Whitney U test, Chi-Square test; t-test and Spearman correlation coefficient for inter group comparison. RESULTS: The females were younger than males in all cervical stages. The CS1-CS2 show the period before the peak of growth, during CS3-CS5 it's the pubertal growth spurt and CS6 is the period after the peak of the growth. The mean age and standard deviation for cervical stages of CS2, CS3 and CS4 were 12.09 ±1.72 years, 13.19 ±1.62 and 14.88 ±1.52 respectively. The Spearman correlation coefficients between cervical vertebrae and dental maturation were between 0.166 and 0.612, 0.243 and 0.832 for both sexes for upper and lower third molars. The significance levels for all coefficients were equal at 0.01 and 0.05. CONCLUSION: The results of this study showed that the skeletal maturity increased with the increase in dental ages for both genders. An early rate of skeletal maturation stage was observed in females. This study needs further analysis using a larger sample covering the entire dentition.

Craniofacial and Dental Defects in the Col1a1Jrt/+ Mouse Model of Osteogenesis Imperfecta.

Certain mutations in the COL1A1 and COL1A2 genes produce clinical symptoms of both osteogenesis imperfecta (OI) and Ehlers-Danlos syndrome (EDS) that include abnormal craniofacial growth, dental malocclusion, and dentinogenesis imperfecta. A mouse model (Col1a1(Jrt)/+) was recently developed that had a skeletal phenotype and other features consistent with moderate-to-severe OI and also with EDS. The craniofacial phenotype of 4- and 20-wk-old Col1a1(Jrt)/+ mice and wild-type littermates was assessed by micro-computed tomography (µCT) and morphometry. Teeth and the periodontal ligament compartment were analyzed by µCT, light microscopy/histomorphometry, and electron microscopy. Over time, at 20 wk, Col1a1(Jrt)/+ mice developed smaller heads, a shortened anterior cranial base, class III occlusion, and a mandibular side shift with shorter morphology in the masticatory region (maxilla and mandible). Col1a1(Jrt)/+ mice also had changes in the periodontal compartment and abnormalities in the dentin matrix and mineralization. These findings validate Col1a1(Jrt)/+ mice as a model for OI and EDS in humans.

Dental age assessment on panoramic radiographs in a Swiss population: a validation study of two prediction models.

OBJECTIVES: Dental age assessment methods are widely used for age estimation. This study aimed to analyse the accuracy of a meta-analysis method to estimate dental age in Swiss individuals and to detect potential limitations of the method. Precision of repeated tooth staging using Demirjian's classification on maxillary and mandibular teeth was also assessed. METHODS: Panoramic radiographs of 50 Swiss white healthy children were analysed. Developing teeth on the left maxilla and mandible and all third permanent molars were staged following Demirjian's classification. Dental age was calculated for each subject, using a random effects model and a fixed effect model, and compared with chronological age. RESULTS: The mean error of the dental age ranged between -3 and +1 months for both the calculation models. Dental age calculated with the fixed effect model overestimated the age of the subjects (average + 0.10 y, ranging from -1.95 y to +2.16 y) compared with their chronological age, whereas the random effects model underestimated the age (average -0.32 y, ranging from -2.24 y to +1.61 y). CONCLUSIONS: Demirjian's method allowed a precise repeated staging of maxillary and mandibular developing teeth. For both calculation models, dental age correlated well, on average, with chronological age of Swiss subjects younger than 12 years. The random effects model showed a better accuracy for these subjects than the fixed effect model. However, both models underestimated the chronological age in subjects older than 12 years.

Evaluation of skeletal and dental age using third molar calcification, condylar height and length of the mandibular body.

AIM: To identify the most reliable method for age estimation among three variables, that is, condylar height, length of mandibular body and third molar calcification by Demirjian's method. MATERIALS AND METHODS: Orthopantomograms and lateral cephalograms of 60 patients with equal gender ratio were included in the study, among each gender 15 subjects were below 18 years and 15 subjects were above 18 years. Lateral cephalograms were traced, height of condyle and mandibular body are measured manually on the tracing paper, OPG's were observed on radiographic illuminator and maturity score of third molar calcification was noted according to Demirjian's method. All the measurements were subjected to statistical analysis. RESULTS: The results obtained are of no significant difference between estimated age and actual age with all three parameters (P > 0.9780 condylar height, P > 0.9515 length of mandibular body, P > 0.8611 third molar calcification). Among these three, length of mandibular body shows least standard error test (i.e. 0.188). CONCLUSION: Although all three parameters can be used for age estimation, length of mandibular body is more reliable followed by height of condyle and third molar calcification.