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.

Patterns of molar agenesis associated with p.P20L and p.R77Q variants in PAX9.

Nonsyndromic tooth agenesis is associated with variants in several genes. There are numerous genotype-phenotype publications involving many patients and kindreds. Here, we identified six Thai individuals in two families with nonsyndromic tooth agenesis, performed exome sequencing, and conducted functional experiments. Family 1 had four affected members carrying the heterozygous PAX9 variant, c.59C>T (p.Pro20Leu). The p.Pro20Leu was previously reported in two families having four and three affected members. These seven cases and Proband-1 had agenesis of at least three third molars. Family 2 comprised two affected members with agenesis of all 12 molars. Both individuals were heterozygous for c.230G>A (p.Arg77Gln) in PAX9, which has not been reported previously. This variant is predicted to be damaging, evolutionarily conserved, and resides in the PAX9 linking peptide. The BMP4 RNA levels in Proband-1's leukocytes were not significantly different from those in the controls, whereas BMP4 levels observed in Proband-2 were significantly increased. Moreover, the p.Arg77Gln variant demonstrated nuclear localization similar to the wild-type but resulted in significantly impaired transactivation of BMP4, a PAX9 downstream gene. In conclusion, we demonstrate that the PAX9 p.Pro20Leu is highly associated with absent third molars, while the novel PAX9 p.Arg77Gln impairs BMP4 transactivation and is associated with total molar agenesis.

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.

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.

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.

A combination of kissing molars, maxillary bilateral supernumerary teeth and macrodontia: a rare case report.

BACKGROUND: Supernumerary teeth (ST) is defined as an additional number of teeth compared to the normal dental formula. The prevalence rate of ST varies from 0.5 to 3.8% in the permanent dentition. When ST located distal to the third molar is acclaimed as distomolar. Moreover, kissing molar is an extremely scarce condition of distomolars, pointed in the opposite direction in a single follicular space. Meanwhile, macrodontia is also a rare shape anomaly characterized by a large crown and tapering root. CASE PRESENTATION: A 22-year-old Chinese man presented a combination of kissing molars, maxillary bilateral supernumerary teeth and macrodontia. Radiographically, two maxillary bilateral distomolars located at the buccal side of adjacent third molars. One mandibular distomolar with the adjacent third molar was contacted by occlusal surfaces while roots were pointed oppositely, which could be diagnosed as KM. Furthermore, the left mandibular third molar can be inferred to be a macrodontia, characterized by a large crown and tapering root. After a thorough investigation, we excluded the possibilities of systemic diseases and genetic inheritance. However, the etiology of this rare combination deserves to be further explored. CONCLUSION: The combination of kissing molars, maxillary bilateral supernumerary teeth and macrodontia is very rare, especially presented in the patient with no syndromes. As there were no complications with these conditions, long-term observation has been recommended for the patient. In addition, the true etiology need a further exploration.

The role of clinical examination in the detection of permanent maxillary molars with two palatal roots.

BACKGROUND: The aim of the study was to determine whether the presence of two palatal roots (2PR) in permanent maxillary molars (PMMs) could be predicted by observing dental morphological traits during the clinical examination. MATERIALS AND METHODS: A total of 18 second and 26 third PMMs with 2PR were examined from the collection of extracted teeth. The reference sample of 44 extracted PMMs with one palatal root was selected such that pairs of morphologically matching PMMs with one and 2PR were formed. The external morphology of these tooth pairs was examined under a stereomicroscope and distinguishing traits were registered. The Fisher's exact test was applied to examine differences between second and third PMMs. Additionally, the external morphology of 17 PMM with 2PR in 15 patients was analysed retrospectively. RESULTS: Extracted PMMs with 2PR possessed the following distinguishing morphological traits: crown wider on the palatal half (55.3%), double Carabelli cusps (23.7%), pronounced palatal indentation of the crown (20.5%), thick palatal enamel extension (16.3%), palato-radicular groove (11.6%) and palatal enamel pearl (2.3%). Differences between second and third PMMs were not statistically significant (p > 0.05). At least one distinguishing trait was present in 63.4% and 94.1% of extracted and clinically evaluated PMMs with 2PR, respectively. Omega-shaped deformation of the dental arch may be the first clinically observable clue to this root constellation. CONCLUSIONS: Clinical examination of tooth morphology and shape of the dental arch is essential for the detection PMMs with 2PR.

Association of molar incisor hypomineralization with premature birth or low birth weight: systematic review and meta-analysis.

Objective: Molar incisor hypomineralization (MIH) is a kind of enamel hypomineralization. MIH has a serious negative impact on patient's oral health. Whether neonates with premature birth or low birth weight are susceptible to MIH has not been rigorously evaluated. The purpose of this systematic review and meta-analysis was to determine whether premature birth and low birth weight increased the possibility of developing MIH in neonates.Method: We searched relevant studies published from 2001 to June 2018 on PubMed and Embase. The methodological quality of the studies included in the meta-analysis was assessed using the Agency for Health Care Research and Quality (AHRQ) inventory tool.Results: Premature birth promoted the prevalence of MIH (OR = 1.57, 95%CI: 1.07-2.31). Low-birth-weight neonates were approximately three times likely to suffer from MIH (OR = 3.25, 95%CI: 2.28-4.62).Conclusions: Our finding suggests that premature birth and low birth weight increase the prevalence of MIH.

A three-dimensional analysis of primary failure of eruption in humans and mice.

OBJECTIVES: Primary failure of eruption (PFE) is a genetic disorder exhibiting the cessation of tooth eruption. Loss-of-function mutations in parathyroid hormone (PTH)/parathyroid hormone-related peptide (PTHrP) receptor (PTH/PTHrP receptor, PPR) were reported as the underlying cause of this disorder in humans. We showed in a PFE mouse model that PTHrP-PPR signaling is responsible for normal dental follicle cell differentiation and tooth eruption. However, the mechanism underlying the eruption defect in PFE remains undefined. In this descriptive study, we aim to chronologically observe tooth eruption and root formation of mouse PFE molars through 3D microCT analyses. SETTING AND SAMPLE POPULATION: Two individuals with PFE were recruited at Showa University. A mouse PFE model was generated by deleting PPR specifically in PTHrP-expressing dental follicle and divided into three groups, PPRfl/fl ;R26RtdTomato/+ (Control), PTHrP-creER;PPRfl/+ ;R26RtdTomato/+ (cHet), and PTHrP-creER;PRRfl/fl ;R26RtdTomato/+ (cKO). MATERIALS AND METHODS: Images from human PFE subjects were acquired by CBCT. All groups of mouse samples were studied at postnatal days 14, 25, 91, and 182 after a tamoxifen pulse at P3, and superimposition of 3D microCT images among three groups was rendered. RESULTS: Mouse and human PFE molars exhibited a similar presentation in the 3D CT analyses. The quantitative analysis in mice demonstrated a statistically significant decrease in the eruption height of cKO first and second molars compared to other groups after postnatal day 25. Additionally, cKO molars demonstrated significantly shortened roots with dilacerations associated with the reduced interradicular bone height. CONCLUSIONS: Mouse PFE molars erupt at a much slower rate compared to normal molars, associated with shortened and dilacerated roots and defective interradicular bones.

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.

The prevalence of three-rooted permanent mandibular molars in a Slovenian population: A radiographic study.

Background: Three-rooted permanent mandibular molars (PMMs) have great clinical significance and interesting geographical distribution. Aim: The aim of this retrospective study was to assess their prevalence among a Slovenian dental school patient population. Materials and methods: A total of 3668 PMMs (1361 first, 1573 second, and 734 third) were evaluated by means of intraoral (periapical and bite-wing) radiographs that were collected from dental records of 1317 patients (708 females and 609 males) aged 13-92 years (mean age 37.3 years). The radiographs were evaluated independently by two observers under optimal conditions using a viewing box and a magnifying glass. 95% confidence intervals (CI) for the prevalence of three-rooted PMMs in the population were estimated using Wald's method. The Fisher's exact test was applied to examine any statistically significant difference among PMM groups, between left and right teeth and between male and female patients. Results: Three roots were identified in 1.32% [0.82%-2.10%, 95% CI] of the evaluated first PMMs, 0.25% [0.07%-0.61%, 95% CI] of second, and 1.77% [1.01%-3.04%, 95% CI] of third PMMs. The overall prevalence of three-rooted PMMs was 0.95% [0.68%-1.33%, 95% CI]. The second PMM was less often affected than the first or the third PMM (p < 0.001). No statistically significant differences for three-rooted first, second and third PMMs were detected with respect to sex (p > 0.05) or the side of occurrence (left vs. right side, p > 0.05). Conclusions: A relatively low prevalence of three-rooted PMMs in the examined Slovenian population is in agreement with the available data for Europeans. Three-rooted variants occur least frequently in second PMMs. From a clinical viewpoint, the possibility of three-rooted PMMs should always be considered and looked for, even when treating indigenous European patients.

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)

Investigation of maxillofacial morphology and oral characteristics with Turner syndrome and early mixed dentition.

Turner syndrome is associated with an X chromosome abnormality in women and is characterized by infantilism, congenital webbed neck, and cubitus valgus. The aim of this study was to determine the maxillofacial morphology and oral characteristics of Japanese girls (mean age, 8.5 years) with Turner syndrome and early mixed dentition. Lateral cephalograms obtained at the first visit were used to analyze maxillofacial morphology. Oral characteristics were identified using orthopantomograms, intraoral photographs, and study casts. All patients received growth hormone. Lateral cephalograms showed a retrognathic maxilla and mandible and a small gonial angle. Nine patients had a high-arched palate. Nine patients had class II first molar relationship occlusion and one had mesial step-type occlusion. Three patients showed ectopic eruption of the maxillary first permanent molar accompanied by resorption of the maxillary second primary molar. Eruption of the permanent teeth tended to occur early. The median mesiodistal diameter of the maxillary central incisor was smaller than the Japanese norm. Ectopic eruption of the maxillary first permanent molar may be caused by lack of eruption space and a discrepancy between bone growth and timing of tooth maturation.

Molar Incisor Hypomineralization: paediatricians should be involved as well!

Tooth structure anomalies affect the deciduous or permanent dentition with varying degrees of severity, depending on the odontogenesis phase in which the disturbance factor occurs. Some forms are clearly increasing and becoming of common clinical observation, as is the case of MIH (Molar Incisor Hypomineralization) whose prevalence ranges from 3 to 25%. However, often stucture anomalies are still under-diagnosed. Early diagnosis should be within the reach of all clinicians (both dentist and non-dentist), and is essential for improving the treatment outcome and quality of life of affected patients. The objectives of treatment consist in the resolution of the symptoms and in the aesthetic, morphological and functional restoration of the affected teeth, which can be achieved with a multidisciplinary approach. Therefore, in order to prevent damage to the teeth with structure anomalies, early visits and close follow-ups are necessary. In children the first dental visit is recommended at the age of 3-4 years, however in the presence of important dental abnormalities of the deciduos dentition, the paediatrician or the parents should request a visit even at a younger age. Because of the sensitivity that is often associated with these disorders, in fact, daily tooth brushing is often inadequate. It is therefore important to inform the parents and instruct them to intervene in order to maintain proper oral hygiene. Finally, special attention should also be paid to the diet, which should not be cariogenic and exclude foods and drinks with acidic pH. Perhaps it would be appropriate to share this information with the paediatricians and general practitioners we collaborate with: I am sure that a better knowledge of this dental condition will translate into an even earlier diagnosis and improved treatment outcomes for our (and their) patients! What are your thoughts about it?