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.

Axenfeld-Rieger syndrome � report of a rare case and review

A typical case of Axenfeld-Rieger syndrome (ARS), a rare autosomal dominant condition manifesting with ocular, craniofacial, and dental abnormalities, is presented. The patient showed dental features such as oligodontia, microdontia, abnormally shaped teeth, hyperplastic maxillary labial frenum, and maxillary retrognathism. Early diagnosis of the syndrome from its dentofacial manifestations and a multidisciplinary approach is required for the management of patients with ARS.

Implant hybrid prosthetic treatment in Down syndrome patient: a case report

Down syndrome patients generally have poor oral hygiene due to lack of awareness and ability to perform oral care, and there is a high risk of tooth loss. Also, they are characterized by small and irregular teeth and oligodontia, which makes it difficult to do prosthetic treatment. This article reports a case of implant hybrid prosthesis treatment of maxillary edentulous area in Down syndrome patient. The external shape of the final prosthesis was determined by using the mandibular artificial teeth to reflect the oligodontia of the mandible and the pontic areas were adjusted to facilitate oral hygiene care. As a result, aesthetically and functionally satisfactory results were obtained.

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.

Dental Management of Ectodermal dysplasia: A case report.

A variety of syndromes/disorders (genetic/acquired) are encountered in our day-to-day life. Among them, ectodermal dysplasia is a rare syndrome which is transmitted as x-linked recessive/dominant disorder and is known to majorly affect males as compared to females. Clinically, it is observed that there is presence of partial or complete anodontia with conical teeth along with maxillary retrusion, prominent supraorbital ridges or frontal bossing, fine and blond, scanty hair (resembling lanuogo), deformed or absent nails, facial physiognomy (fairy-like face) and reduced sweating. Early diagnosis remains the key for the management of ectodermal dysplasia. Since patient suffers from unpleasant appearance (due to partial or complete anodontia); hence, dental management includes replacement of teeth by either fixed/removable partial or complete dentures /implant- supported dentures. We present a case of ectodermal dysplasia with features of oligodontia, severely deficient alveolar processes and maxillary retrusion which was managed with tooth-supported complete overdentures.

Oral Rehabilitation of Patients with Hypohidrotic Ectodermal Dysplasia: When, Why and How to Intervene.

Ηypohidrotic ectodermal dysplasia (HED) patients present absence of many permanent teeth, alveolar deficiency and severely affected maxillofacial skeleton. The management commonly includes a series of removable dentures and orthodontic appliances, adapted constantly to the child's growth and development. The dental literature lacks a protocol to elucidate when, why and how to intervene for the modification of jaw growth pattern and for the treatment of dental and occlusal problems to maximize the clinical therapeutic outcome. The aim of the present review was to propose and redefine the treatment plan for the orofacial rehabilitation of patients with HED. Normal craniofacial growth is described, followed by a review of published findings about facial growth in HED patients. Subsequently, the treatment strategy is presented, focusing on the stages of physical growth and dental development: (a) infancy and early childhood (primary dentition years), (b) late childhood (mixed dentition years), (c) adolescence (early permanent dentition years) and (d) adulthood (permanent dentition years), and to the special characteristics related to each developmental stage. Finally, the treatment possibilities and restrictions are considered, and a protocol defining when, why and how to intervene is proposed.

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.

Reconstruction of implant prostheses under infraocclusion: a case report / 대한치과보철학회지

Implant has been an effective treatment option for the patients with oligodontia. However, it still remains unclear when the implant should be placed. Skeletal growth that can appear even after the growth period can lead to infraocclusion of the implant which can cause functional or esthetic complications. In order to minimize these problems, definitive restorations should be placed after the functional and esthetic rehabilitation is achieved through the use of provisional restorations. Definitive restorations made with monolithic zirconia were created by replicating provisional restorations by using the latest CAD/CAM technology. These definitive restorations were delivered to the patient and clinical observation after the treatment showed satisfactory result.

Displasia ectodérmica hipohidrótica: características clínicas y radiográficas / Hypohidrotic ectodermal dysplasia: clinical and radiographic characteristics

Displasia ectodérmica hipohidrótica (DEH) es una enfermedad genética rara de carácter autosómico recesivo ligado al cromosoma X; abarca un conjunto de desórdenes que envuelven tejidos derivados del ectodermo, siendo afectados el sexo masculino y portadores el sexo femenino. Presentan una tríada típica: hipohidrosis, oligodoncia e hipotricosis. Se reporta el caso clínico de un paciente con signos característicos de DEH: piel reseca, cabellos, cejas y pestañas escasos; arrugas e hiperpigmentación perioral y periorbitales; labios y puente nasal prominentes y disminución de secreción lagrimal. En el examen intraoral se observaron ausencias múltiples de piezas dentarias, con presentación de sólo ocho dientes superiores y dos inferiores, todos ellos con alteración de forma y presencia de diastemas. El reconocimiento y tratamiento odontológico precoz de los individuos portadores de DEH, referidos a alteraciones bucales, es de vital importancia no solamente por ofrecer un aspecto funcional y estético favorables sino también porque permite en corto plazo reducir alteraciones en el crecimiento facial.

Hypohidrotic ectodermal dysplasia (HED) is a rare genetic condition. It is of recessive autosomic character and linked to the X chromosome, encompassing a heterogeneous group of disorders involving ectoderm-derived tissues. Males are affected by the disease and females play the role of carriers. This disease presents a typical triad: hypohidrosis, oligodontia and hypotrichosis. This article examines the clinical case of a patient who exhibited characteristic signs of HED: dry skin, scarce hair eyebrows and eyelashes, wrinkles and peri-oral and peri-orbital hyperpigmentation, prominent lips and nasal bridge and decreased lachrymal secretion. Intra-oral examination revealed multiple tooth absences, presence of only eight teeth in the upper jaw and two teeth in the lower jaw, all with shape alterations and presence of diastemata. Early recognition and dental treatment of HED carrier individuals referred to oral alterations is of the utmost importance, not only to achieve favorable esthetics and functionality but also to allow the decrease facial growth alterations in a short time.

A Female Child with Oligodontia in Primary Dentition – Report of a Rare Case.

Aims: Non-Syndromic congenital absence of primary dentition is rare. A female child with congenital absence of primary incisors (n=6) is presented. Presentation of Case: A 4 year-old non-syndromic female child reported with missing several teeth. Intraoral examination revealed absence of (n=6) all four Mandibular Primary Incisors and two Maxillary Primary Lateral Incisors. Radiographic examination revealed absence of corresponding permanent tooth buds. Discussion: The management of this situation is critical for the child and parent point of view due to higher number of missing teeth and early age of reporting. The hypodontia leads to speech problems with lowered self esteem and restricted diet causing malnourishment. Management options include Removable partial denture, Speech therapy, orthodontic jaw expansion, Mini implants. Conclusion: This report presents a rare case of Oligodontia in female child of 4 years old and various management options.

Clinical and genetic evaluation of a family with isolated oligodontia / 实用医学杂志

Objectives To investigate the mutational characteristics of MSX1 and PAX9 genes in a family affected by non-syndromic oligodonti so as to study the pathogenesis of oligodontia from a molecular prospective. Methods A family with oligodontia, but of different descent and unrelated healthy controls were enrolled in our study. Genomic DNA was isolated from the blood samples. Mutation analyses were performed by amplifying MSX1 and PAX9 exons and sequencing the products. Results DNA sequencing revealed a novel missense mutation c.348C>T in a highly conserved homeobox sequence of MSX1 and a known polymorphisms c. 469+35- c.469+45del in exon 1 and in intron in the two patients and in two unrelated healthy controls. But we did not detect any mutation in PAX9. Conclusion Our finding suggests the samesense mutation (c.348C>T) and the polymorphisms (c.469+35- c.469+45del) may be responsible for oligodontia phenotype in this Chinese family.

A rare case report of Oligodontia in the permanent dentition.

Oligodontia is a rare congential disorder of dental anomalies that can occur either as an isolated finding or as part of a syndrome. It is defined as agenesis of six or more teeth excluding the third molars. It is commonly seen in permanent than in deciduous dentition. Patients suffering from oligodontia may present with complex problem such as dental and facial disfigurement. Management of those cases generally requires multidisciplinary approach to restore esthetic and function. This paper reports a rare case of oligodontia in an 18 year old adult female patient who has been missing eight permanent teeth excluding the third molars, clinically and radiographically.

Ectodermal dysplasia: familial report of six cases.

Ectodermal dysplasia is a hereditary disease characterized by a congenital dysplasia of one or more ectodermal structures and their accessory appendages. There are two main types, Hypohidrotic/Christ-Seimens- Tourian Syndrome and Hidrotic/Clouston syndrome. Common manifestations include defective hair follicles and eyebrows, frontal bossing with prominent supraorbital ridges, nasal bridge depression and protuberant lips. Intraorally common findings are anodontia or hypodontia and conical shaped teeth. The patient may suffer from dry skin, hyperthermia and unexplained high fever because of the deficiency of sweat glands. The present article reports unique case series of ectodermal dysplasia cases in two families, where three generations in the both the families were affected.

Oligodontia: challenges in dental rehabilitation

Oligodontia, although rare, may have significant impact on the quality of life of those affected with it. Provision of restorative treatment for these patients can be very challenging and demanding for clinicians, especially during the active growth phase. Nevertheless, the dental needs of these patients are real and should be addressed appropriately. The present case report described a restorative rehabilitative plan and execution of different restorative treatment modalities in a 14-year-old patient with oligodontia. The challenges faced in the provision of dental care were highlighted. The treatment outcome showed a positive psychological impact on the well-being of the patient based on parental observations.

Manejo multidisciplinario de oligodoncia no asociado a síndrome. Reporte de caso / Multidisciplinary management of non syndrome oligodontia. Case report

Objetivo: describir el manejo multidisciplinario proporcionado a una niña de 7 años con oligodoncia no asociada a s¡ndrome. Reporte de caso: Paciente femenino de 7 años de edad acude al servicio de Odontología Pediátrica de la Clínica Dental de la Universidad Peruana Cayetano Heredia, para tratamiento integral, refiriendo un diagnostico presuntivo de Displasia Ectodérmica. Al examen clínico, la paciente presenta placas hipopigmentadas con descamación en zonas localizadas del cuerpo; al examen clínico estomatológico presenta el labio inferior ligeramente evertido, pérdida de la dimensión vertical, oligodoncia de piezas deciduas y al examen radiográfico se evidencia la agenesia de múltiples piezas permanentes. Como parte del tratamiento integral se realizaron interconsultas con pediatr¡a, dermatología y genética para llegar a un diagnostico sistémico definitivo, el cual fue Oligodoncía no asociada a síndrome, descartando así el diagnóstico presuntivo inicial. También se incluyeron interconsultas con las especialidades de rehabilitación oral, ortodoncia, estética y periodoncia para llegar a un adecuado tratamiento odontológico. Después de un estudio minucioso del caso, se confeccionó un plan de tratamiento odontológico preventivo y rehabilitador en el que se realizó profilaxis y aplicación de flúor barniz, resinas simples en las segundas molares superiores deciduas, reconstrucción de los incisivos centrales inferiores deciduos y aumento de la altura clínica de la primera molar inferior decidua; luego se confeccionó la prótesis parcial inferior para as¡ devolver la función masticatoria, fonética y estética. Conclusiones: El manejo odontológico de los pacientes con Oligodoncía debe ser multidisciplinario, con la finalidad de mejorar su alimentación, fonética y estética, lo cual beneficia su proceso de aceptación y socialización...

Objective: to describe the multidisciplinary management provided to a 7 years old girl with non syndromic oligodontia. Case report: female patient of 7 years old presents with her parents to the Dental Clinic’s department of Pediatric Dentistry at the Universidad Peruana Cayetano Heredia, for integral treatment, referring a presumptive diagnosis of ectodermal dysplasia. At the clinical examination, the patient had hypopigmented scaly plaques in localized areas of the body, the clinical stomatological examination presents slightly everted lower lip, loss of vertical dimension, oligodontia of the deciduous teeth and radiographic examination evidence agenesis of multiple permanent teeth. As part of the integral treatment interconsultations were performed with pediatrics, dermatology and genetics to reach a definitive systemic diagnosis, which was non syndromic oligodontia, thus ruling out the initial presumptive diagnosis. Interconsultations were also included with the specialties of oral rehabilitation, orthodontics, periodontics and aesthetic to reach an appropriate dental treatment. After a careful study of the case,, it was made a preventive and dental rehabilitations treatment plan which include prophylaxis and fluoride varnish application, simple resin to the second upper deciduous molars, reconstruction of deciduous mandibular central incisor and increasing clinical height of the first deciduous molar, then the lower partial denture was made to restore masticatory function, phonetics. Conclusions: the dental management of patients with oligodontia should be multidisciplinary, with the aim of improving their diet, phonetics and esthetics, which benefits the process of acceptance and socialization. The functions of the Pediatric dentists are managing patient behavior and interaction with parents, as well as preventing future injuries of dental caries and keep healthy primary teeth as long as possible.

Rehabilitación protésica sobre implantes en paciente con oligodoncia / Prosthetic rehabilitation on implants in patients with oligodontia

Fundamento: la rehabilitación a través de implantes dentarios ha sido un medio eficaz para la sustitución de dientes perdidos o ausentes. Presentación del caso: paciente de 25 años de edad, portadora de prótesis parcial acrílica superior por oligodoncia de incisivos laterales superiores, con lesiones en la mucosa oral. La paciente es tratada por un equipo multidisciplinario y se rehabilitó con prótesis fija soportada por implantes. Conclusiones: la implantología como medio de soporte en la rehabilitación protésica resultó efectiva en una paciente con oligodoncia de incisivos laterales superiores, con mejoría en la estética, la autoestima y la función.

Background: rehabilitation through dental implants has been an effective means for the replacement of lost or absent teeth. Case presentation: 25 year old patient, holder of an acrylic upper partial prosthesis due to oligodontia of upper lateral incisive and lesions in the oral mucous membrane. The patient is treated by a multidisciplinary team and was rehabilitated with a fixed prosthesis supported by implants. Conclusions: Implantology as a means of support in prosthetic rehabilitation resulted effective in a patient with oligodontia of upper lateral incisive with aesthetic improvement, function and self esteem.

Non-syndromic oligodontia in permanent dentition: a rare case report / Oligodontia não sindrômica nad entição permanente: relato de caso raro

Tooth agenesis is one of the most common congenital anomalies seen in humans. Although absence of one or more teeth is common, absence of multiple teeth is rare. Oligodontia is a rare developmental anomaly, involving agenesis of six or more permanent teeth, excluding the third molars. The reported prevalence of oligodontia in permanent dentition is 0.14%. Oligodontia can be presented as an isolated condition or as a part of a syndrome. Discussion: The present case report highlights a unique case of non-syndromic oligodontia, with agenesis of four permanent incisors, left permanent canine and right second premolar in the mandibular arch and its management with a novel fixed functional prosthetic appliance. Conclusion: Prosthetic rehabilitation is an urgent need for these kind of patients so that they do not suffer from masticatory and esthetic problems which can eventually lower the self esteem of individuals...

A agenesia dentária é uma das anomalias congênitas mais comuns em humanos. Embora a ausência de um ou mais dentes seja comum, a ausência de vários dentes é rara. A oligodontia é uma anomalia de desenvolvimento rara, envolvendo agenesia de seis ou mais dentes permanentes, excluindo os terceiros molares. A prevalência de oligodontia na dentição permanente é de 0,14%. A oligodontia pode apresentar-se como uma condição isolada ou como parte de uma síndrome. Discussão: O presente relato destaca um caso único de oligodontia não sindrômica, com agenesia de quatro incisivos permanentes, canino permanente esquerdo e segundo pré-molar direito no arco inferior, e seu manejo com um novo aparelho de prótese fixa funcional. Conclusão: A reabilitação protética é uma necessidade urgente para este tipo de paciente para que ele não sofra de problemas de mastigação e estética, os quais podem eventualmente reduzir a autoestima do indivíduo...

Multidisciplinary Therapy of Extensive Oligodontia: A Case Report

Oligodontia is a rare congenital disorder consisting in the absence of six or more teeth. This case report describes a multidisciplinary treatment approach for a 12-year-old male with absence of 11 permanent teeth. Prior to any procedure, all primary teeth were scheduled for extraction due to poor crown-to-root ratio. The treatment plan comprised two phases: 1. orthodontic and speech therapy aimed at overbite and anterior open bite adjustment, as well as tongue position improvement; and 2. prosthetic treatment by insertion of removable temporary partial dentures. The multidisciplinary treatment involving orthodontics, speech and prosthetic therapies have reestablished the masticatory function and aesthetics, allowing the patient to achieve greater self-esteem and better social acceptance.

Resumo A oligodontia é uma doença rara, congênita, caracterizada pela ausência de seis ou mais dentes. Este relato de caso descreve uma abordagem terapêutica multidisciplinar de um adolescente de 12 anos de idade com ausência de 11 dentes permanentes. Antes de qualquer procedimento, todos os dentes decíduos foram extraídos devido à pobre relação coroa-raiz. O plano de tratamento foi constituído por duas fases: 1. terapia ortodôntica e fonoaudiológica com o objetivo de ajuste de sobre-mordida e mordida aberta anterior, bem como melhoria da posição da língua, e 2. tratamento reabilitador protético através da instalação de próteses parciais removíveis provisórias. A abordagem multidisciplinar envolvendo os tratamentos ortodônticos, fonoaudiológico e protético reestabeleceram a função mastigatória e a estética, melhorando a autoestima e aceitação social do paciente. .