Prevalence, Severity, and Description of Dental Anomalies in Children Treated for Acute Lymphoblastic Leukemia.

Purpose: To assess the prevalence and severity of and describe dental anomalies in children treated for acute lymphoblastic leukemia (ALL) under recent Dana-Farber Cancer Institute (DFCI) protocols. Methods: Patients aged between 14 and 25 years old having received a diag- nosis of ALL before the age of 11 years and after September 2000 received clinical and radiographic oral examinations. Results: Dental anomalies were observed in 26 (51.0 percent) of 51 subjects. Microdontia was the most prevalent dental defect (39.2 percent). Impacted permanent second molars were observed in five (9.8 percent) patients. Being age five years or younger at diagnosis significantly increased the prevalence and severity of dental anomalies (P<0.001). Conclusions: Recent DFCI protocols showed a decreased prevalence of dental disturbances. The anomalies observed may still alter the development of the dental arches and occlusion in pediatric ALL survivors. Further research is needed to confirm the association between ALL treatment and permanent second molar impaction.

Is there an association between molar incisor hypomineralization and developmental dental anomalies? A case-control study.

BACKGROUND: The aim of this study was to determine whether there is any association between molar incisor hypomineralization and developmental dental anomalies. METHODS: Two pediatric dentists evaluated panoramic radiographs of 429 children aged 8-14 years with molar incisor hypomineralization (study group) and 437 children without molar incisor hypomineralization (control group) in terms of developmental dental anomalies. Twelve different developmental dental anomalies were categorized into four types: size (microdontia, macrodontia); position (ectopic eruption of maxillary permanent first molars, infraocclusion of primary molars); shape (fusion, gemination, dilaceration, taurodontism, peg-shaped maxillary lateral incisors); and number (hypodontia, oligodontia, hyperdontia) anomalies. RESULTS: No significant difference was observed in the frequencies of developmental dental anomalies between the study and control groups in total, females, and males (p > 0.05). A statistically significant difference was found between the distribution of developmental size, position, shape, and number anomalies between the study and control groups (p = 0.024). The most common anomaly in both groups was hypodontia (6.3% and 5.9%, respectively). There was a significant difference between the study and control groups in terms of subtypes of shape anomaly in all children and females (p = 0.045 and p = 0.05, respectively). CONCLUSIONS: While a significant difference was observed between the distributions of types of developmental dental anomalies between individuals with and without molar incisor hypomineralization, there was no difference in terms of the frequency of developmental dental anomalies.

Radix em molares decíduos inferiores: revisão sistemática com metanálise / Radix in lower primary molars: systematic review with meta-analysis

Objective: To estimate the prevalence of three roots in deciduous mandibular molars. Methodology: Electronic searches were carried out in PubMed and Scopus to identify cross-sectional studies published up to September 2023. The Joanna Briggs Institute tool was used to critically appraise the studies. STATA 16.0 was used to generate risk of bias figures and perform the meta-analysis. Results: Eighteen studies evaluating 9,067 patients (8,969 first molars and 10,765 second molars) were included in this review. The overall prevalence of radix in mandibular deciduous molars was 9.61% (3.67% for first molars and 18.72% for second molars). The prevalence rate of teeth diagnosed using Cone Beam Computed Tomography (CBCT) was similar to the diagnoses made using conventional radiographic techniques together (periapical, interproximal and panoramic). Final considerations: Lower deciduous molars with three roots have a prevalence of almost 10%, with a higher prevalence in second molars. The diagnosis of this morphological alteration can be made using conventional radiographic techniques, but the use of CBCT is recommended.(AU)

Objetivo: estimar a prevalência de três raízes em molares inferiores decíduos. Metodologia: foram realizadas buscas eletrônicas na PubMed e Scopus para identificar estudos transversais publicados até setembro/2023. Para a avaliação crítica dos estudos foi utilizada a ferramenta do Instituto Joanna Briggs. STATA 16.0 foi usado para gerar figura do risco de viés e realizar a metanálise. Resultados: dezoito estudos que avaliaram 9.067 pacientes (8.969 primeiros molares e 10.765 segundos molares) foram incluídos nesta revisão. A prevalência global de radix em molares decíduos inferiores foi de 9,61% (3,67% para primeiros molares e 18,72% para segundo molares). A taxa de prevalência de dentes com diagnóstico através de Tomografia Computadorizada Cone Beam (TCCB) foi semelhante aos diagnósticos realizados pelas técnicas radiográficas convencionais em conjunto (periapical, interproximal e panorâmica). Considerações finais: os molares decíduos inferiores com três raízes têm uma prevalência de quase 10%, com maior prevalência em segundo molares. O diagnóstico desta alteração morfológica pode ser feito através das técnicas radiográficas convencionais, porém recomenda-se a utilização de TCCB.(AU)

Prevalence and extent of Alveolar dehiscence and fenestration in Class I hyperdivergent subjects with different buccolingual inclinations of maxillary molar teeth: a CBCT study

Buccolingual position of teeth could affect the prevalence of alveolar bone defects. Presence of alveolar defects may have a deleterious effect on orthodontic treatment. The aim was to assess the prevalence and extent of dehiscence and fenestration in Class I hyperdivergent subjects and correlate it with buccolingual inclinations(BL) of maxillary first molar teeth. Methods: This retrospective study involved 80 CBCTs of class I hyperdivergent subjects divided into two groups - group A (n=33) buccolingual inclination >9º and group B (n=47) buccolingual inclination <9º. Prevalence and extent of alveolar bone dehiscence and fenestrations were measured in CBCTs using OSIRIX Lite software. Descriptive statistics, Mann Whitney U test and Spearman correlation were done for evaluating intergroup differences and correlation with Buccolingual inclination. Results: Overall prevalence of dehiscence and fenestration in maxillary first molars was 60.95% and 5% respectively. In the buccal alveolar bone, prevalence of dehiscence was highest in group A (84.6%) for 16 and in the lingual alveolar bone prevalence of dehiscence was highest in group B (71.4%) for 26 . On intergroup comparison, the extent of lingual alveolar bone dehiscence (26) in group B was significantly higher (p value <0.05) than in group A. No significant correlation between the extent of dehiscence and fenestration with buccolingual inclination of molar teeth was noted. Conclusion: Molar teeth with BL inclinations of more than 9º had higher prevalence of dehiscence on the buccal side and molar teeth with BL inclinations less than 9 degrees had more dehiscence on the lingual side. But no significant correlation of BL inclination with prevalence and extent of dehiscence and fenestration was noted

Guidance for Permanent First Molar Extraction in Molar-Incisor Malformation: Report of Two Cases.

Molar-incisor malformation (MIM) is a newly described dental developmental anomaly that predominantly affects primary second molars, permanent first molars, and, in some cases, permanent central incisors. Diagnosis is usually made upon radiographic examination. The molars usually present with significant cervical constriction, flattened pulp chambers, and absent or thin, short, and narrow roots, whereas the incisors usually exhibit coronal dilaceration. Loss of these compromised teeth in the long term may be inevitable. Thus, clinicians should be aware of this condition and the factors to consider to advise their patients as early as possible. The purpose of this paper is to present two cases of MIM and discuss the factors clinicians should take into consideration to make a care plan in these cases.

What are the Systemic Factors Associated with the Molar-Incisor Hypomineralization Etiology?

ABSTRACT Objective: To evaluate the systemic factors associated with Molar-Incisor Hypomineralization (MIH) etiology. Material and Methods: A total of 731 8-year-old schoolchildren enrolled in the public school system in Curitiba, Brazil, was randomly selected. The MIH diagnosis was performed by calibrated examiners (Kappa >0.80) according to the European Academy of Pediatric Dentistry criteria (2003). The systemic factors were collected through a semi-structured questionnaire and applied to the children's mothers, addressing the medical history from pregnancy to the first three years of children's life. Associations were analyzed by Poisson regression analysis with robust variance (p<0.05). Results: The systemic factors in the prenatal and perinatal periods were not associated with MIH (p>0.05). The children who used medications during the first years of life had a significantly higher prevalence of MIH (PRc = 2.18 CI = 95% 1.06-4.48; p=0.033). Conclusion: The use of medications during the first three years of children's life is associated with a higher prevalence of MIH.

Radiographic Assessment of Third Molars Agenesis Patterns in Young Adults

ABSTRACT Objective: To determine the prevalence of third molar agenesis and associated characteristics. Material and Methods: A total of 2374 panoramic radiographs were retrieved from the radiological archives and evaluated in a computer monitor under optimum viewing conditions. The basic demographic data (age and sex) and the primary findings regarding the presence or absence of third molars in the maxillary and mandibular arches were recorded systematically in a specially designed proforma. Categorical variables were compared using the Chi-square test. Results: A total of 2000 panoramic radiographs were included in the study, of which 1004 were females (50.2%), and 996 were of males (49.8%). The incidence of third molar agenesis was 486 patients (24.3%). Maxillary third molar showed a higher prevalence of agenesis (28.8%) than mandibular third molars (16.4%). A total of 1514 patients (75.7%) had third molars in all four quadrants, and the remaining 486 patients (24.3%) had agenesis of third molar tooth in at least one of the quadrants. Single tooth agenesis was observed in 219 (11%) patients, two teeth agenesis in 172 (8.6%) patients, three teeth agenesis in 39 (2%) patients, and four teeth agenesis in 56 (2.8%) patients. Conclusion: The present study exhibited a maximum number of single tooth agenesis. It was also observed that maxillary third molar agenesis is more than the mandibular third molar and the right side is more than the left side. Agenesis of the third molar is more prevalent in males as compared to females.

Molar-incisor malformation: a narrative review

Introduction: "Molar-incisor malformation" (MIM) or "Molar root-incisor malformation" is a recently reported dental anomaly of unknown etiology, possibly associated with systemic complications, which affects the development of first permanent molar roots and dental enamel of central incisors. Objective: To conduct a literature review on "Molarincisor malformation", also known as "Molar root-incisor malformation", discussing its clinical, radiographic/tomographic and microscopic aspects; differential diagnosis and treatment possibilities. Sources of data: Electronic search was performed on the MEDLINE database in March 2021, without limit regarding the year of publication. The terms used were "molar-incisor malformation", "molar-root incisor malformation", "root malformation", "root development", "tooth roots", "abnormalities". Synthesis of data: Fifteen articles, most of them case series, were included. In general, medical historyrevealed clinical complications during pregnancy and / or the first years of life. Clinical features included tooth enamel defects in the cervical region of incisors and marked mobility of permanent molars and incisors. Radiographically, partially obliterated pulp chambers, short, thin and incomplete roots of first permanent molars and incisors, were observed. Microscopically, the occurrence of a hypercalcified dentin layer, in the form of a lens, inside the pulp chamber, at the level of the cementum-enamel junction, called"mineralized cervical diaphragm", was reported. Conclusion: "Molar-incisor malformation" is an anomaly characterized by changes in root development, pulp chamber and enamel in permanent molars and incisors. The differential diagnosis includes Dentin Dysplasia type I and Regional Odontodysplasia. Medical and familyhistories are essential for the final diagnosis, and treatment, which despite not having an established protocol, requires a multidisciplinary approach and conventional treatments such as tooth extraction, endodontics, orthodontics, and dental implants.

Introdução: "Malformação molar-incisivo" (MIM) ou "Malformação radicular molarincisivo" é uma anomalia dental recém-reportada de etiologia desconhecida, possivelmente associada a complicações sistêmicas, que afeta o desenvolvimento de raízes dos primeiros molares permanentes e esmalte dentário de incisivos centrais. Objetivo: Realizar uma revisão da literatura sobre "Malformação molar incisivo", também conhecida como "Malformação raiz-molar incisivo", discutindo seus aspectos clínicos, radiográficos/tomográficos, diagnóstico diferencial e possibilidades de tratamento. Fonte dos dados: Busca eletrônica foi realizada na base MEDLINE, em março de 2021, sem limite quanto ao ano de publicação. Os termos pesquisados foram "molarincisor malformation", "molar-root incisor malformation", "root malformation", "root development", "tooth roots", "abnormalities". Síntese dos dados: Quinze artigos, na maioria série de casos, foram incluídos. Em geral, a história médica revelou complicações clínicas durante a gestação e/ou primeiros anos de vida. As características clínicas incluíram defeitos de esmalte dentário na região cervical de incisivos e mobilidadeacentuada de molares e incisivos permanentes. Radiograficamente, observou-se a presença de câmaras pulpares parcialmente obliteradas, raízes de molares e incisivos permanentes curtas, finas e incompletas. Microscopicamente, reportou-se a ocorrência de camada de dentina hipercalcificada, em forma de lente, no interior da câmara pulpar, ao nível da junção cemento-esmalte, denominada de "diafragma cervical mineralizado". Conclusão: A "Malformação molar-incisivo" é uma anomalia caracterizada por alterações do desenvolvimento radicular, da câmara pulpar e do esmalte em molares e incisivos permanentes. O diagnóstico diferencial inclui Displasia dentinária tipo I e Odontodisplasia regional. Históricos médico e familiar são essenciais para o diagnóstico final, e o tratamento, o qual apesar de não ter protocolo estabelecido requer abordagem multidisciplinar e tratamentos convencionais como exodontia, endodontia, ortodontia e implantes dentários.

Odontodisplasia Regional y Agenesia de Premolares. Reporte de un Caso / Regional Odontodysplasia and Premolar Agenesis. Case Report

RESUMEN: La odontodisplasia regional (OR) es una alteración en el desarrollo, no hereditario y que afecta tanto la dentición temporal como la dentición definitiva. Involucra a los tejidos mesodérmicos y ectodérmicos de los dientes lo que es condescendiente con hallazgos clínicos, radiográficos e histológicos. Su etiología aun es desconocida y se presenta mayoritariamente en mujeres. Clínicamente puede afectar al maxilar, a la mandíbula o ambas arcadas pero generalmente solo se ve comprometida una ellas, principalmente el más afectado es el hueso maxilar. Radiográficamente se observa una pobre diferencia entre los tejidos del esmalte y la dentina, siendo tejidos menos radiopacos que su contraparte sana generando un aspecto descrito como "diente fantasma". Histológicamente se observan zonas hipocalcificadas del esmalte con un orden de prismas irregulares mientras que la dentina se observa con un número reducido de túbulos dentinarios y de consistencia más fibrosa en su zona coronal. El tratamiento de la OR es controversial ya que su incidencia es baja y la literatura al respecto no es clara. El objetivo de este manuscrito, fue reportar un caso de OR y revisar la literatura relacionada. Presentamos un caso de OR en una paciente de 12 años que presenta ausencia de los dientes 2.4, 2.5 y 2.6; restos radiculares y agenesia de los dientes 3.5 y 4.5. Se describirán sus aspectos clínicos, radiográficos e histológicos. Se realizó una búsqueda sistemática en las siguientes bases de datos: Clínical key, Science Direct, PubMed y SciELO.

ABSTRACT: Regional odontodysplasia (RO) is a variation in the development; it is not hereditary and it affects both deciduous and permanent dentition. It involves the mesodermal and ectodermal tissues of dental pieces, and coincides with clinical, radiographic and histological findings. Its etiology is still unknown and it reportedly occurs mostly in women. Clinically it can affect the maxilla, mandible or both arches but generally only one is compromised, mainly the maxilla which is affected the most. Radiographically there is limited difference between enamel and dentin tissue, which is less radiopaque than their healthy counterpart, generating an aspect described as "phantom tooth". Histologically hypocalcified areas of the enamel are observed with an irregular order of prisms while the dentine is observed with a reduced number of dentinal tubules and more fibrous consistency in the coronal area. RO treatment is controversial since its incidence is low and the literature on these events is not clear. The aim of this manuscript was to report a case of RO and review related literature. We present a case of RO in a 12-year-old patient who presents absence of parts 2.4.2.5 and 2.6; radicular remains and agenesis of parts 3.5 and 4.5. Its clinical, radiographic and histological aspects are described. A systematic search was carried out in the following databases: Clinical key, Science Direct, PubMed and SciELO.

Salvaging a Periodontally Compromised and Endodontically Involved Three-Rooted Mandibular First Molar With Cervical Enamel Projection.

This case report describes the management of a mandibular first molar with an additional distolingual root (radix entomolaris) and grade III cervical enamel projection through a multidisciplinary approach. Diagnosis for the case was endodontic-periodontal lesion due to non-vitality and associated advanced periodontal destruction. The patient was treated with drainage of the periodontal abscess with adjunct antibiotics, phase I periodontal therapy, endodontic therapy, radiculoplasty, regenerative periodontal therapy, replacement of the missing right mandibular second molar, and long-term maintenance. Follow-up of the patient up to 9 months has been uneventful. Cases of advanced periodontal destruction typically show some degree of tooth mobility, which was absent in this case. The article discusses the tripod effect as well as the increased surface area for periodontal attachment provided by the additional root contributing to the non-mobility of the involved tooth.

Neonatal molar in a child with Langerhan cell histiocytosis.

Teeth which erupt in the 1st month of postnatal life are known as "neonatal tooth." The incidence of these teeth ranges from 1:2000 to 1:3500 live births. Natal teeth are more common in mandibular central incisor region, followed by maxillary incisor region and mandibular canine region. The neonatal or natal teeth in the maxillary molar region are a rare occurrence. This article represents a rare case of the neonatal tooth with Langerhans cell histiocytosis.

Distomolares en posición ectópica (kissing molars): reporte de un caso / Distomolars in ectopic position (kissing molars): report of a case

Introducción: El término kissing molars se traduce como «dientes besándose¼; superfi cies oclusales de dos molares retenidos están en contacto una con otra en espacio folicular único y raíces en dirección contraria. Literatura científi ca ha reportado 44 casos. Cuartos molares o distomolares, supernumerarios que se forman distalmente a terceros molares; tamaño y forma variable, generalmente retenidos. Caso clínico: Femenino de 32 años con molestias en zona retromolar inferior izquierda, limitación de apertura, trismus, disfagia. En ortopantomografía, se observa cuarto molar retenido junto con tercer molar, superfi cies oclusales de ambos órganos dentarios retenidos en íntimo contacto dentro de un mismo saco folicular, raíces en dirección opuesta. Discusión: Existe controversia acerca de diferencia entre molares retenidos y KM, algunos autores sugieren que la ausencia de contacto entre dos molares retenidos no permite incluirlos en esta condición. Etiología aún incierta, algunos lo consideran como un evento aislado. Existe una teoría en relación con la formación de quiste dentígero; resorción ósea causada por presencia y expansión de éste, resulta en pérdida de hueso en zona mesial de molares retenidos facilitando movilización, inclinación y contacto uno con otro (AU)

Introduction: The term kissing molars is used when the occlusal surfaces of two retained molars are in intimate contact inside the same follicular sack and roots in opposite direction. Literature has reported 44 cases. Fourth molars, also known as distomolars, are a supernumerary tooth that grows distally to third molars; size and shape are variable, generally retained. Case report: Female 32 years old, pain in the left inferior retromolar zone, trismus, dysphagia. Fourth and third retained molars, with occlusal surfaces in contact, inside the same follicular sack, roots in opposite direction are observed in orthopantomography. Discussion: There is controversy about the diff erence between retained molars and KM, some authors suggest that the absence of contact between two retained molars, does not allow to include them in this condition. Etiology still unknown. Dentigerous cyst formation theory is proposed due to the bone resorption in the mesial zone of retained molars in this entity, which facilitates mobilization and contact between molars (AU)

Permanent mandibular protostylid: A rare developmental anomaly and its overview.

Developmental malformations of the teeth might result in alterations of their size, shape, and structure. An accessory cusp is a developmental alteration to the shape of the teeth and is more commonly found in anterior teeth, and its occurrence in permanent molars is quite rare. Accessory cusps occurring in permanent mandibular molars are termed as protostylids. Although they do not pose any significant problem with respect to the function and occlusion, it is of tremendous importance in forensic odontology. This case report presents a rare finding of protostylid on the permanent mandibular molar, and its clinical implications are illustrated.

Five canals on mandibular first molar successfully managed by undergraduate dental student: an educational case report

Undergraduate dental student's eligibility and ability to treat difficult endodontic cases is a new area open for debate. a fifth year undergraduate dental student managed to perform a successful root canal treatment (RCT) on a 42 year old male patient diagnosed as a rare case of mandibular first molar with five root canals. as an educational case report, in a country like Sudan, close supervision and clinical training of undergraduate students in treating difficult endodontic cases is recommended.

Analysis of Cause of Endodontic Failure of C-Shaped Root Canals.

The purpose of this study was to analyze various characteristics and classification of C-shaped root canals and evaluate the causes of endodontic failure of C-shaped root canals by examining the resected root surface with an endodontic microscope and a scanning electron microscope (SEM). Forty-two teeth with C-shaped root canals were included in this study and had undergone intentional replantation surgery. Before surgery, periapical radiography and cone-beam computed tomography were taken. The root canal configuration was analyzed and classified according to Melton's classification at coronal and apical level. After injection of 1 : 100,000 epinephrine with 2% lidocaine, the tooth was carefully extracted. After the root-end resection, the resected root surface was examined using an operating microscope and SEM. Mandibular second molars were most frequently involved teeth (90.4%). The most frequently observed root canal configurations were C1 at the coronal level (45.2%) and C3 at the apical 3 mm level (45.2%). The most common cause of failure for a C-shaped root canal treatment was a leaky canal (45.2%), followed by an isthmus (23.8%), missing canal, overfilling, and iatrogenic problems. In conclusion, C-shaped root canals were most frequently found in mandibular second molars. The most common cause of failure was a leaky canal and isthmus.

Taurodontism and its forensic value: a case report.

Taurodontism is an anomaly that affects posterior teeth, vertically increasing the size of the pulp chamber, mimicking the shape of bovine teeth, being only evidenced in diagnostic images. This report describes a case of taurodontism in a mandibular second molar, highlighting the forensic importance of this dental anomaly with relevant potential for human identification, not only for its morphological aspect but also for its relatively low frequency in mandibular second molars. In the case under study, the individual did not have any restored teeth. Thus, the set of diverse imaging modalities is fundamental to identify the anatomy of teeth and roots, the only information that could be used in a hypothetical identification situation, assigning to this anomaly an exceptional relevance as a potential characteristic for positive identification.

Endodontic management of taurodontism with a complex root canal anatomy in mandibular posterior teeth.

One of the biggest challenges in endodontic treatment is to comprehensively understand the variation of tooth root canal anatomy. To a large degree, the anatomy and furcation distribution of teeth, which vary from nationality and ethnic groups, will influence the clinical diagnosis, treatment plan and even prognosis. Taurodontism, as one of anatomic variation in tooth structures, is relatively hard to be seen in dental clinics. Two special cases of taurodontism with varied root canal anatomies in mandibular second premolar and first molar are reported in this paper.

Examination of paramolar tubercles in Turkish population using cone beam computed tomography / Estudio de los tuberculos paramolares en una población turca mediante tomografía computarizada de haz cónico

SUMMARY: Paramolar tubercle (PT) is an additional cusp occuring on buccal surface of both upper and lower permanent molars. PT is also known as parastyle when tubercle is present in upper molars, as protostylid when tubercle is present in lower molars. The aim of this study was to evaluate prevalence of PTs in Turkish population with cone beam computed tomography (CBCT). Presence of PT in molar teeth were evaluated retrospectively using CBCT images of 210 patients (102 male, 108 female) between 18-77 years old. A total of 909 teeth were analyzed. Because of various reasons some teeth were excluded and final analyze was done with 653 teeth. Prevalence of PT was found as 2.76 % (18 out of 653). Highest frequency of PT was detected 5 in #27, 4 in #17, 2 in #48 among all molar teeth respectively. In two cases; 2 PTs were on the same tooth, bilateral PT was found only in one case. PT was undetected on upper first molars. Prevalence of PTs on permanent molars is a rare phenomenon in the studied population. Use of CBCT in such anatomic variations will provide valuable and detailed information during treatment modalities. Since this pilot study represents Turkish subpopulation, comprehensive studies with increased number of cases should be undertaken to clarify the prevalence of paramolars in Turkish population. Advanced imaging techniques like CBCT will be more helpful in understanding and detecting exact morphological and anatomical variations of PTs during treatment modalities.

RESUMEN: El tubérculo paramolar (TP) es una cúspide adicional que está en la superficie vestibular de los molares permanentes superiores e inferiores. El objetivo de este estudio fue evaluar la predisposición de TP en la población turca con tomografía computarizada de haz cónico (TCHC). Presencia de TP en dientes molares se evaluaron retrospectivamente utilizando imágenes de tomografia de 210 pacientes (102 hombres, 108 mujeres) entre 18-77 años de edad. Se analizó un total de 909 dientes. Por varias razones, algunos dientes fueron excluídos y el análisis final se realizó con 653 dientes. Prevalencia de PTP se encontró en el 2,76 % (18 dientes de 653). La frecuencia más alta de TP se detectó: 5 en # 27, 4 en # 17, 2 en # 48, entre todos los dientes molares, respectivamente. En dos casos, 2 de los TP fueron observados en el mismo diente; TP bilateral sólo se encontró en un caso. El TP no fue detectado en los primeros molares superiores. La prevalencia de TP en los molares permanentes es un fenómeno poco frecuente en la población estudiada. El uso de la TCHC en tales variaciones anatómicas, proporcionará información valiosa y detallada para definir la aplicación de diferentes modalidades de tratamiento. Dado que este estudio piloto representa a una subpoblación turca, estudios exhaustivos con un mayor número de casos deben llevarse a cabo para determinar la prevalencia en la población turca total. Técnicas avanzadas de imagen como TCHC serán más útiles para detectar variaciones morfológicas y anatómicas exactas de TP durante diversas modalidades de tratamiento.

The Impact of the Eda Pathway on Tooth Root Development.

The Eda pathway ( Eda, Edar, Edaradd) plays an important role in tooth development, determining tooth number, crown shape, and enamel formation. Here we show that the Eda pathway also plays a key role in root development. Edar (the receptor) is expressed in Hertwig's epithelial root sheath (HERS) during root development, with mutant mice showing a high incidence of taurodontism: large pulp chambers lacking or showing delayed bifurcation or trifurcation of the roots. The mouse upper second molars in the Eda pathway mutants show the highest incidence of taurodontism, this enhanced susceptibility being matched in human patients with mutations in EDA-A1. These taurodont teeth form due to defects in the direction of extension of the HERS from the crown, associated with a more extensive area of proliferation of the neighboring root mesenchyme. In those teeth where the angle at which the HERS extends from the crown is very wide and therefore more vertical, the mutant HERSs fail to reach toward the center of the tooth in the normal furcation region, and taurodont teeth are created. The phenotype is variable, however, with milder changes in angle and proliferation leading to normal or delayed furcation. This is the first analysis of the role of Eda in the root, showing a direct role for this pathway during postnatal mouse development, and it suggests that changes in proliferation and angle of HERS may underlie taurodontism in a range of syndromes.