A novel mutation in the WNT6 gene of congenital tooth agenesis / 口腔疾病防治

Objective @#This article explores the relationship between congenital tooth agenesis and related gene mutations, providing a reference for early diagnosis of the disease.@*Methods @# Clinical and radiographic examinations of a rare case of congenital tooth agenesis were conducted to evaluate the abnormal morphology and quantity of the teeth, as well as the overall health of the patient. Bidirectional sequencing of the PAX9 and MSX1 genes and whole-exome sequencing were conducted to identify potential genetic abnormalities. Sanger sequencing of the newly discovered mutation site was performed on the proband's son. Subsequently, the impacts of the mutations were evaluated through computational tools and a cell-based gene transfection assay. @*Results @#This is a rare case of tooth agenesis characterized by a congenitally missing first molar, a second molar with one single root and a supernumerary second premolar in the right mandibular dentition. The c.717 C>C/T in PAX9 is synonymous. The c.119C>G in MSX1 is a missense mutation predicted to be “benign” by Polyphen. Through whole-exome sequencing, we found a novel mutation, c.637-7 C>A in intron 3 of the WNT6 gene, which is predicted by MAXENT to influence the splicing of mRNA. Both the proband and his son carry this mutation. A cell-based gene transfection assay demonstrated that it did not alter the mRNA splicing of WNT6. @* Conclusion @#The interaction between single nucleotide polymorphisms may contribute to congenital tooth agenesis.

Preliminary study of familial nonsyndromic tooth agenesis caused by ectodysplasin A mutation / 口腔疾病防治

Objective@# To explore the pathogenic genes in a Chinese family affected by nonsyndromic tooth agenesis so as to study the pathogenesis of oligodontia.@*Methods @# Hospital ethical approval and informed consent of the patients and family members were obtained. Clinical data of the proband and close family members were collected, peripheral venous blood was collected, and DNA was extracted. Gene sequencing was performed through whole-exome sequencing, and then the screened pathogenic genes were verified by Sanger sequencing. The three-dimensional structure of the mutant proteins was analyzed and compared with the wild-type using bioinformatics tools.@*Results@#The two patients with congenital majority tooth loss in this family were cousins, and there were no other patients with congenital majority tooth loss in the family. Besides congenital multiple tooth loss, the two patients had no obvious hair abnormalities, finger/toe abnormalities, sweating abnormalities or other abnormal manifestations of ectodermal tissue. We found a mutant gene that in this family by carrying out gene sequencing of the patients and their close family members. A novel EDA (ectodysplasin A) missense mutation c.983C>T (p. Pro328Leu) was identified, which changed the encoded amino acid from proline (Pro) to leucine (Leu). Analysis of the mutation site showed that the site was highly conserved, and three-dimensional structure modeling also found that it changed the structure of EDA. @* Conclusion@#A novel EDA missense variant (c.983C>T, p.Pro328Leu) was first identified in a Chinese family with nonsyndromic tooth agenesis, extending the mutation spectrum of the EDA gene.

Research progress on selective tooth agenesis caused by LRP6 gene mutation / 口腔疾病防治

@#Selective tooth agenesis (STA) is an abnormal number of teeth due to genetic factors or the environment and is most commonly observed for permanent teeth. LRP6 is one of the common causative genes of STA and is inherited by an autosomal dominant mechanism, leading to non-syndrome tooth agenesis (NSTA) or syndrome tooth agenesis (STA). NSTA is only involved in tooth number and appearance abnormalities, whereas STA caused by LRP6 gene mutation results abnormal ear development, oral-facial clefting, sparse hair and hypohidrosis. In this paper, we review the phenotype and gene mutation traits of selective STA caused by LRP6 gene mutation identified in recent years and describe 38 patients with tooth agenesis from 24 mutation sites of LRP6 gene. We analyzed the percentage of missing teeth and found that the lateral incisor in the maxilla and the second premolar in the maxilla and mandible were most commonly lost, whereas all central incisors in the maxilla remained. LRP6 gene plays a major role in tooth development via the WNT/β-catenin signaling pathway, and LRP6 gene mutation can lead to a series of abnormal manifestations due to the disruption of the signaling pathway. The literature showed that LRP6 gene mutations occurred mostly at the E1 or E2 subdomain, meaning that STA due to the mutants extracellularly disturbed the WNT/β-catenin signaling pathway. However, mature treatments for selective congenital tooth loss are lacking.

Novel PAX9 compound heterozygous variants in a Chinese family with non-syndromic oligodontia and genotype-phenotype analysis of PAX9 variants

Abstract Studies have reported that >91.9% of non-syndromic tooth agenesis cases are caused by seven pathogenic genes. Objective To report novel heterozygous PAX9 variants in a Chinese family with non-syndromic oligodontia and summarize the reported genotype-phenotype relationship of PAX9 variants. Methodology We recruited 28 patients with non-syndromic oligodontia who were admitted to the Hospital of Stomatology Hebei Medical University (China) from 2018 to 2021. Peripheral blood was collected from the probands and their core family members for whole-exome sequencing (WES) and variants were verified by Sanger sequencing. Bioinformatics tools were used to predict the pathogenicity of the variants. SWISS-MODEL homology modeling was used to analyze the three-dimensional structural changes of variant proteins. We also analyzed the genotype-phenotype relationships of PAX9 variants. Results We identified novel compound heterozygous PAX9 variants (reference sequence NM_001372076.1) in a Chinese family with non-syndromic oligodontia: a new missense variant c.1010C>A (p.T337K) in exon 4 and a new frameshift variant c.330_331insGT (p.D113Afs*9) in exon 2, which was identified as the pathogenic variant in this family. This discovery expands the known variant spectrum of PAX9; then, we summarized the phenotypes of non-syndromic oligodontia with PAX9 variants. Conclusion We found that PAX9 variants commonly lead to loss of the second molars.

Novel mutations identified in the WNT10A gene and implant rehabilitation of patients with severe tooth agenesis / 口腔疾病防治

Objective@#To detect WNT10A gene mutations in patients with oligodontia or anodontia (≥6 teeth missing) and analyze their dental phenotype. @*Methods@#Patients with oligodontia or anodontia were enrolled from the clinic for oral examination, genetic history collection and whole exon sequencing, and patients with WNT10A gene mutations were included. Sanger sequencing was utilized to validate the WNT10A gene variations in probands and family members compared with the normal sequence. The pathogenicity of WNT10A mutations was evaluated by functional prediction, conservation analysis and structure prediction of protein mutants. Implant rehabilitation was applied to restore the patients' oral function.@*Results@# Five WNT10A gene mutations were detected in six unrelated patients, and c.26G>A (p. Trp9X) and c.1036delT (p. Cys346fs) were novel mutations with pathogenic potential. The mean number of missing teeth was (15.33±8.64) per case. The most frequently missing permanent teeth were maxillary canines (100%), and the least frequently missing teeth were mandibular first molars (25%). Implant rehabilitation was applied in five patients, and patients were found to have ideal implant osseointegration and functional restoration.@*Conclusion @# This study identified novel WNT10A gene pathogenic variants, enriching the WNT10A gene spectrum and providing new evidence for genetic diagnosis and prenatal consultation. Implant rehabilitation was also proven to be a treatment option for these patients.

Association between tooth agenesis and cancer: a systematic review

Abstract The congenital absence of multiple teeth may share the same genetic background of the development of some types of cancer. Objective: This systematic review aimed to investigate the possible association between dental agenesis and cancer, and the perspective of agenesis as an early predictor for cancer risk. Methodology: The electronic databases PubMed, Scopus, Web of Science, Cochrane Library, LILACS, and OpenGrey were searched and the risk of bias was evaluated using the Newcastle-Ottawa tool. The GRADE tool was used to evaluate the certainty of the evidence. Results: Six studies met the eligibility criteria. A positive co-occurrence between ovarian cancer and hypodontia was found in two articles. Three studies evaluated the association between dental agenesis and colorectal cancer and only one showed common genes for these conditions. One paper found individuals with hypodontia had a higher risk of family history of cancer. Five studies had a fair quality and one a good quality. The certainty of evidence was classified as very low. Conclusion: Notwithstanding the limited scientific evidence, there may be a possible association between dental agenesis and cancer due to genes involved in both conditions. Agenesis of multiple teeth could be an early indicator of cancer risk. Nevertheless, studies with a better level of evidence are needed to confirm this possible association.

Prosthodontic Rehabilitation of Bilateral Maxillary Lateral Incisors Agenesis: A Case Report with One-Year Follow-Up

ABSTRACT@#Globally, non-syndromic tooth agenesis is commonly seen in clinical practice. However, its management is often complex and requires a multidisciplinary team approach for the maximal outcome. While various treatment options are possible, considerations for the treatment are not only based on the dentofacial conditions but also cultural and social background and personal preference of the patient. Thus, patientcentred care approach should always be practised for an optimal outcome. In the present case, a patient with established craniofacial growth presenting with bilateral agenesis of maxillary lateral incisors and over-retained deciduous maxillary left canine sought for aesthetic improvements. The patient did not prefer any orthodontic treatment citing a prolonged treatment duration and sub-optimal motivation as a hindrance. Thus, a prosthodontic only approach was taken by providing a conventional cantilever bridge and ceramic veneers to achieve the aims of treatment. This article discusses the possible limitation of such prosthodontic only solution in managing tooth agenesis.

Association between hypodontia of permanent maxillary lateral incisors and other dental anomalies

ABSTRACT Introduction: Tooth agenesis is often associated with other tooth anomalies, such as microdontia, delayed eruption and ectopic eruption. Moreover, they may be found all in the same individual, as certain genetic mutations may have a variable phenotypic expression. Treatment of cases of hypodontia of anterior teeth should not involve only opening or closing space for prosthetic rehabilitation. Individuals with hypodontia of permanent maxillary lateral incisors may have teeth with a mesiodistal width smaller than that of patients with a normal dentition, and which may need reshaping to achieve an esthetic and functional occlusion. Objective: This clinical case report discusses the association of hypodontia of permanent maxillary lateral incisors with other tooth anomalies and their treatment alternatives.

RESUMO Introdução: As agenesias dentárias são frequentemente associadas a outras anomalias dentárias, tais como microdontia, atraso na erupção e ectopismo. Além disso, podem vir todas juntas em um mesmo indivíduo, pois certas mutações genéticas podem se expressar fenotipicamente de diferentes formas. A abordagem terapêutica nos casos de hipodontia de dentes anteriores não deve se pautar somente entre fechar ou abrir espaço para substituição protética. Portadores de hipodontia de incisivos laterais superiores permanentes podem apresentar os outros dentes com largura mesiodistal menor que os de pacientes com dentição normal, e podem necessitar de reanatomizações para que se obtenha uma oclusão dentária estética e funcional. Objetivo: Dessa forma, o objetivo do presente artigo é relatar um caso clínico e discutir a associação da hipodontia de incisivos laterais superiores permanentes com outras anomalias dentárias, e suas alternativas de tratamento.

Dental Rehabilitation of a Rare Hallermann-Streiff Syndrome with Olygodontia: A Case Report / Rehabilitación dental de un caso raro de Síndrome de HallermannStreiff con Oligodoncia: Reporte de un caso

Abstract Hallermann-Streiff syndrome (HSS) is a rare oculomandibulofacial discephaly with hypotrichosis that occurs as a sporadic mutation. It is characterized by abnormal findings especially in head and face. Dental anomalies occur in 50-80% of the patients. In this case report, facial-oral findings and the existing dental anomalies of the syndrome in a 6-year-old male patient diagnosed with HSS were identified. Dental rehabilitation and a 12-month follow-up of the patient were reported. Each case presented with this rare syndrome may contribute to the literature to determine the prognosis of the disease and to take protective and preventive measures.

Resumen El síndrome de Hallermann-Streiff (HSS) es una discefalia oculomandibulofacial rara con hipotricosis que ocurre como una mutación esporádica. Se caracteriza por hallazgos anormales, especialmente en cabeza y cara. Las anomalías dentales ocurren en 50-80% de los pacientes. En este reporte de caso, se identificaron los hallazgos faciales-orales y las anomalías dentales existentes del síndrome en un paciente masculino de 6 años diagnosticado con HSS. Se informó la rehabilitación dental y un seguimiento de 12 meses del paciente. Cada caso presentado con este síndrome raro puede contribuir a la literatura para determinar el pronóstico de la enfermedad y tomar medidas de protección y prevención.

Research progress on pathogenic genes and molecular mechanisms of nonsyndromic tooth agenesis / 口腔疾病防治

@#Tooth agenesis is a common tooth number deficiency that occurs in the tooth-forming process or earlier period of tooth germ development and has a serious impact on the maxillofacial development, aesthetics and masticatory function of patients. According to the presence or absence of systemic symptoms, tooth agenesis can be divided into syndromic tooth agenesis and nonsyndromic tooth agenesis. In recent years, the discovery of new related genes, new mutation sites and related molecular mechanisms has become a major direction of gene research. This article will review the current research progress of the signaling pathways related to nonsyndromic tooth agenesis, such as the WNT/beta-catenin pathway, TGF-β/BMP pathway, PAX9, MSX1, and the EDA/EDAR/NF-κb pathway, and their molecular mechanisms. The interaction between Pax9 activating the Wnt/β-catenin and TGF-β/BMP pathways, MSX1 activating the TGF-β/BMP pathway, and Wnt activating the EDA/EDAR/NF-κb pathway was also found, which provides a new theoretical basis for the prevention and treatment of tooth agenesis. The molecular mechanism of nonsyndromic tooth agenesis is rarely studied; thus, the exploration of its mechanism will become one of the main research directions in the future.

Detection of EDA gene mutation and phenotypic analysis in patients with hypohidrotic ectodermal dysplasia / 北京大学学报(医学版)

OBJECTIVE@#To detect the ectodysplasin A (EDA) gene mutation in patients with hypohidro-tic ectodermal dysplasia (HED), and to analyze the distribution pattern of missing permanent teeth and the systemic manifestation of HED patients with EDA gene mutation.@*METHODS@#Twelve HED families were enrolled from clinic for genetic history collection, systemic physical examination and oral examination. Peripheral blood or saliva samples were collected from the probands and the family members to extract genomic DNA. PCR amplification and Sanger sequencing were utilized to detect the EDA gene variations, which were compared with the normal sequence (NM_001399.5). The functional impact of EDA gene variants was then evaluated by functional prediction of mutation, conservation analysis and protein structure prediction. The pathogenicity of each EDA gene variation was assessed according to the stan-dards and guidelines of the American College of Medical Genetics and Genomics (ACMG). The systemic phenotype and missing permanent tooth sites of HED patients with EDA gene mutations were summarized, and the missing rate of each tooth position was analyzed and compared.@*RESULTS@#Eight out of twelve HED families were identified to carry EDA gene mutations, including: c.164T>C(p.Leu55Pro); c.457C>T (p.Arg153Cys); c.466C>T(p.Arg156Cys); c. 584G>A(p.Gly195Glu); c.619delG(p.Gly207Profs*73); c.673C>T(p.Pro225Ser); c.676C>T(p.Gln226*) and c.905T>G(p.Phe302Cys). Among them, c.164T>C(p.Leu55Pro); c.619delG(p.Gly207Profs*73); c.673C>T(p.Pro225Ser); c.676C>T(p.Gln226*) and c.905T>G(p.Phe302Cys) were novel mutations. The HED patients with EDA gene mutations in this study were all male. Our results showed that the average number of missing permanent teeth was 13.86±4.49, the average number of missing permanent teeth in the upper jaw was 13.14±5.76, the missing rate was 73.02%. And in the lower jaw, the average number of missing permanent teeth was 14.57±3.05, the missing rate was 80.95%. There was no significant difference in the number of missing teeth between the left and right sides of the permanent dentition (P>0.05). Specifi-cally, the maxillary lateral incisors, the maxillary second premolars and the mandibular lateral incisors were more likely to be missing, while the maxillary central incisors, the maxillary and mandibular first molars had higher possibility of persistence.@*CONCLUSION@#This study detected novel EDA gene pathogenic variants and summarized the distribution pattern of missing permanent teeth of HED patients, thus enriched the variation and phenotype spectrum of EDA gene, and provided new clinical evidence for genetic diagnosis and prenatal consultation.

Tooth Agenesis and Delay in Patients with Agenesis of Mandibular Second Premolars / 대한소아치과학회지

Tooth agenesis is a common human dental anomaly and the agenesis of mandibular second premolars has been proven to be the most frequently observed. The aim of this study is to investigate tooth agenesis and delayed tooth development in patients with agenesis of mandibular second premolars.This study reviewed 9 to 15 year-old patients with agenesis of mandibular second premolars who visited the department of pediatric dentistry of Yonsei University Dental Hospital and took panoramic radiographs from January 2014 to December 2016. On panoramic radiographs, agenesis of teeth was observed and developmental delay of teeth was evaluated by the Nolla method. Among 125 patients with agenesis of mandibular second premolars, 58 patients (46.4%) showed agenesis of other teeth and 38 patients (30.4%) showed delayed tooth development. In this study, patients with agenesis of mandibular second premolars were more likely to have tooth agenesis or delayed eruption of other teeth.

Suspected non-syndromic Oligodontia - A rare case with 13 agenesis

@#Oligodontia is a condition in which the patient has more than six ageneses, excluding the third molars. Whereas the absence of one tooth is quite common, oligodontia is a rare congenital condition that can happen with or without the syndrome. The condition happens due to disturbances during odontogenesis process. Management of oligodontia is a long-term process, and it involves prosthetic, restorative, and orthodontic treatment to support the oral function and esthetic of the patient. This article aims to report a rare case of agenesis of 13 permanent teeth (excluding third molars) in an 11-year-old girl and her treatment plan.

Agenesis of mandibular second premolar in patient with dental bimaxillary protrusion

ABSTRACT The present study reports the treatment carried out in a patient with mandibular second premolar agenesis associated with early loss of a deciduous second molar, deep overbite, severe overjet and dentoalveolar bimaxillary protrusion, which led to lip incompetence and a convex facial profile. The main objectives of this treatment were: to eliminate the spaces in mandibular arch, correct overbite, as well as eliminate bimaxillary protrusion and lip incompetence, thus leading to a balanced profile. The case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) as part of the requirements to obtain the title of BBO diplomate.

RESUMO O presente caso clínico relata o tratamento de uma paciente com agenesia de segundo pré-molar inferior associada à perda precoce do segundo molar decíduo, sobremordida profunda, sobressaliência exagerada e biprotrusão dentoalveolar, que causavam incompetência labial e perfil facial convexo. Os objetivos do tratamento foram eliminar os espaços presentes na arcada inferior, corrigir a sobremordida, eliminar a biprotrusão e a incompetência labial, harmonizando o perfil. Esse caso foi apresentado ao Board Brasileiro de Ortodontia e Ortopedia Facial (BBO) como parte dos requisitos para obtenção do título de Diplomado pelo BBO.

Early treatment of nonsyndromic oligodontia: a clinical case report / Tratamento precoce da oligodontia não-sindrômica: relato de caso clínico

This report aims to describe the clinical case of a 10-year-old male patient (R.C.B.C.), presenting nonsyndromic oligodontia with maternal family trait and absence of 22 permanent teeth. Clinically, the patient had prolonged retention of some primary teeth and presence of permanent maxillary left central incisor, permanent mandibular right central incisor and four first permanent molars. Radiographically, only permanent maxillary second molars and mandibular third molars were developing, whereas all other germs of permanent teeth were missing. Treatment consisted of maxillary expansion followed by moving permanent maxillary left central incisor bucco-mesially, and rehabilitation of spaces with removable denture, where the main goal was to restore function and esthetic harmony. The case has been monitored for the past six years. Nonsyndromic oligodontia is a rare condition that poses significant functional and psychosocial difficulties. Treatment usually requires a multidisciplinary approach among which pediatric dentistry and orthodontics play a major role. In view of its complexity, treatment should be initiated as early as possible to minimize future functional and aesthetic issues. Dental implants are considered as definitive treatment of cases of oligodontia, however, until the patient reached the ideal age, other treatments to ensure aesthetics and function must be performed.

O objetivo deste trabalho é descrever o caso clínico do paciente R.C.B.C., dez anos de idade, gênero masculino, portador de oligodontia não associada à síndrome, com traço familiar materno e ausência de 22 dentes permanentes. Clinicamente, o paciente apresentava retenção prolongada de alguns incisivos, todos os caninos e molares decíduos e presença do incisivo central superior esquerdo, incisivo central inferior direito e os quatro primeiros molares, todos da dentição permanentes. Radiograficamente, apenas os segundos molares superiores e os terceiros molares inferiores estavam em desenvolvimento, com ausência dos demais germes dos dentes permanentes. Terapeuticamente, foi instituída a expansão maxilar seguida de mesialização e vestibularização do incisivo central superior esquerdo e de reabilitação com prótese removível, sendo o objetivo principal restaurar a harmonia estética e a função. O caso foi acompanhado há seis anos. A oligodontia não-sindrômica é considerada rara e impõe importantes dificuldades funcionais e psicossociais aos seus portadores. Geralmente, o tratamento requer uma abordagem interdisciplinar, onde a odontopediatria e a ortodontia desempenham papel primordial. Devido à complexidade envolvida, o tratamento deve ser iniciado o mais cedo possível, para minimizar futuras questões funcionais e estéticas. Os implantes dentários são considerados como tratamento definitivo para os casos de oligodontia, entretanto, até os pacientes alcançarem a idade ideal, outros tratamentos para garantir estética e função devem ser realizados.

Implantes de diâmetro reduzido (< 3 mm) para reabilitação oral de espaços edêntulos atrésicos em pacientes adolescentes ­ relato de caso com acompanhamento de um ano / Reduced diameter dental implants (< 3 mm) for oral rehabilitation of edentulous atresic spaces

Reabilitações estéticas em áreas anteriores com limitação de espaço mesiodistal tornam-se um desafio. Entretanto, implantes dentários de diâmetros reduzidos (< 3 mm) têm sido utilizados nestes casos. Este relato de caso apresenta a utilização de dois implantes de diâmetro reduzido (2,8 mm) e conexão morse no tratamento de agenesia de laterais superiores. Após planejamento cirúrgico-protético, os implantes foram restaurados imediatamente e acompanhados por um período de um ano. Dentro das limitações deste trabalho, sugere-se que implantes de diâmetro reduzido podem ser utilizados com sucesso para a restauração imediata de laterais superiores, oferecendo um bom perfil de emergência protética e estética para dentes estreitos.

Esthetic rehabilitations in the anterior zones with limited mesiodistal spaces are a great challenge. However, dental implants with reduced diameters (< 3 mm) with a morse taper connection have been used in cases os lateral incisor agenesis. After a detailed surgical-prosthetic planning, the dental implants were immediately restored and followed-up for one year. Within the limits of this paper, it can be suggested that narrower dental implantes can be used with success in such situations, providing a good emergence profile and esthetics to for narrower dental spaces.

Rehabilitation of a patient with non-syndromic partial oligodontia

Oligodontia is defined as a congenital tooth agenesis with the absence of six or more permanent teeth. This clinical report describes a patient with non-syndromic partial oligodontia, with retained deciduous teeth and the absence of 16 permanent teeth. Anterior esthetic problems were caused by interarch tooth size discrepancy, interdental space, aberrant tooth dimensions, and the absence of centric contacts of the anterior teeth. Prosthetic restoration after orthodontic and implant treatment was performed with a multi-disciplinary team approach. Favorable functional and esthetic results were obtained using a definitive prosthesis.

Alteraciones de Número en Dentición de Pacientes entre 2 y 12 Años de Edad con Disrafias Labio Alvéolo Palatina Atendidos en la Unidad de Odontopediatría del Hospital Regional Antofagasta, Chile / Dentition Number Alterations in Patients between 2 and 12 Years of Age with Cleft Alveolus Palate Examined at the Pediatric Dental Unit of the Regional Hospital Antofagasta, Chile

Se realizó un estudio de las alteraciones de número dientes en 71 pacientes entre 2 y 12 años de edad, portadores de Fisura Labio Alvéolo Palatina del Hospital Regional de Antofagasta, atendidos entre Abril del 2004 y Julio del 2010, utilizando las fichas clínicas, radiografías panorámicas, oclusales o periapicales. Se encontró una prevalencia de agenesias dentarias en un 57,75%, de dientes supernumerarios en un 23,95%. Sólo el 18,4% de los niños no presentó alteraciones de número. En la distribución por sexo, en los niños la fisura labial y fisura labio alvéolo palatina bilateral presentó una mayor frecuencia, mientras que en las niñas las fisuras palatinas y fisuras labio alvéolo palatinas unilaterales fueron más frecuentes. Según el tipo de fisura, la más frecuente fue la fisura labio alvéolo palatina unilateral con un 64,79%. La frecuencia de agenesias en el lado de la fisura fue de un 89,3%. El diente más afectado en las agenesias fue el incisivo lateral con un 78,6% en los niños entre 2 a 6 años, y con un 100% en los niños entre 7 y 12 años. Se observó que el 61,5% de los niños con agenesia tenían 1 diente afectado, el 30,8% mostraron 2 dientes afectados y solo el 7,7% presentó 3 o más dientes afectados.

The present study was carried out to research alterations of teeth in 71 patients, whose ages were between two and twelve years old and who exhibited alveolus cleft lip palate. These patients were treated at The Regional Hospital in Antofagasta around April 2004 and July 2010, therefore, we used the tabs clinics, panoramic radiograph, occlusal and periapical radiographs. A prevalence of tooth agenesis in 57.75% of supernumerary teeth in 23.95% was found and 18.4% of children did not show any modification of number. In connection with the distribution by sex of the cleft lip and cleft lip bilateral alveolar palatine presented a high frequency in boys , and the palate clefts with fissure unilateral alveolus cleft lip were frequently observed in girls. Regarding to the types of cleft lip, the most frequent found was the alveolar cleft lip palate unilateral with 64.70% over the total of the fissures. On the other hand, the frequency of agenesis, related to fissure was 89.3%. The most affected tooth in agenesis was the lateral incisor with 78.6% in children whose ages were from 2 to 6 years old, and 100% in children from 7 to 12.It was also observed that 61.5% of children with agenesis had one affected tooth, 30.8 % had two affected teeth and only 7.7% had three or more affected teeth.

Msx1 Gene Variant - its Association in Isolated Hypodontia: A Case Control Genetic study!!!.

INTRODUCTION: Non‑syndromic tooth agenesis is a congenital anomaly with significant medical, psychological, and social ramifications. There is sufficient evidence to hypothesize that locus for this condition can be identified by candidate genes. AIM OF THE STUDY: The aim of this study was to test whether MSX1 671 T > C gene variant was involved in etiology of non‑syndromic tooth agenesis in Raichur patients. MATERIALS AND METHODS: Blood samples were collected with informed consent from 50 subjects having non‑syndromic tooth agenesis and 50 controls. Genomic deoxyribonucleic acid (DNA) was extracted from the blood samples, polymerase chain reaction (PCR) was performed, and restriction fragment length polymorphism (RFLP) was performed for digestion products that were evaluated. RESULTS: The results showed positive correlation between MSX1671 T > C gene variant and non‑syndromic tooth agenesis in Raichur patients. CONCLUSION: MSX1 671 T > C gene variant may be a good screening marker for non‑syndromic tooth agenesis in Raichur patients.

Análise radiográfica de agenesia dentária / Radiographic analysis of tooth agenesis

Introdução: Agenesia é uma anomalia do desenvolvimento dentário frequente no ser humano, e é representada pela ausência de um ou mais dentes, fato relacionado com problemas estéticos e de maloclusão. Objetivo: Investigar a presença de agenesia dental, por meio de radiografias panorâmicas. Materiais e métodos: Foram avaliadas radiografias de pacientes atendidos em três clínicas odontológicas de Presidente Prudente (SP), relacionando a frequência da agenesia com o gênero, quadrantes e grupos dentários afetados. Os critérios de exclusão foram idade e perdas dentais por extrações ou outros motivos. A avaliação das tomadas radiográficas foi executada por dois avaliadores, utilizando negatoscópio em ambiente escuro para possibilitar a análise. Resultados: Foram avaliadas 600 radiografias panorâmicas de pacientes na faixa etária entre 9 e 16 anos. Foram encontrados 171 casos de agenesia; destes, 82 casos foram observados no gênero masculino e 89, no feminino. Quando avaliado o tipo de dente, os terceiros molares apresentaram maior frequência de agenesias (65%), seguido dos segundos pré-molares (5,8%), incisivo lateral (4,8%), primeiro pré-molar e incisivo central (0,6%) em todos os quadrantes, sendo mais frequente no quadrante superior e no gênero feminino. Conclusão: Há prevalência de agenesias no arco superior, com destaque para a do terceiro molar em relação ao de outros dentes. Adicionalmente, sugere-se que o gênero não é um fator predisponente para presença de agenesia.

Introduction: Agenesis is a frequent anomaly of dental development in humans, which is characterized by absence of one or more teeth, and has been related with aesthetic and malocclusion problems. Objective: To investigate the presence of dental agenesis using panoramic radiographs. Materials and methods: Patients radiography of three Dental Clinics of Presidente Prudente, São Paulo State, Brazil, were assessed, and requency of agenesis, gender, and quadrants of dental groups were scored. Exclusion criteria were age and the losses by dental extractions or other reasons. Two reviewers, using negatoscope in a dark room, undertook the analyses of panoramic radiographs. Results: Panoramic radiographs of 600 patients, 9 to 16 years old were evaluated. Agenesis was found in 171 patients, 82 male and 89 female. The third molars had a higher requency of tooth agenesis (65%), followed by the second premolars (5.8%), lateral incisor (4.8%) and one remolar and incisor central (0.6%) on all sides. Agenesis was more frequently found in the upper quadrant and female patients. Conclusion: It was concluded that the agenesis of maxilla and the third molar was the most observed. Additionally it is suggested that gender is not a predisposing factor for the presence of agenesis.