Hypodontia is defined as the developmental absence of one or more teeth which can affect both the primary and permanent dentition. During the diagnosis procedure several other dental and oral symptoms can be observed....Hypodontia is defined as the developmental absence of one or more teeth which can affect both the primary and permanent dentition. During the diagnosis procedure several other dental and oral symptoms can be observed. However esthetic and psychological problems require special attention for these patients, considering that they are often associated with low self-esteem and problems of social acceptance. The optimal therapy should include an interdisciplinary team approach. This review aimed to find out prevalence, causes, clinical manifestations, and treatment modalities of hypodontia. A case report describes that the treatment planning for a patient suffering from oligodontia is introduced at the end of the review. A specialist with the patient together made the decision regarding treatment.展开更多
The ectodermal dysplasias are rare diseases with hypodontia, hypotrichosis and hypohidrosis. The subject's life is considerably constrained and this from an early age, with major difficulties for the integration a...The ectodermal dysplasias are rare diseases with hypodontia, hypotrichosis and hypohidrosis. The subject's life is considerably constrained and this from an early age, with major difficulties for the integration and acceptance of conventional prosthetic occlusal rehabilitation. The use of implants is an integral part of early treatment, in the regions of stable growth, that is to say symphysis. In two childs of 5 and 6 years we have made implant-borne prosthetic rehabilitation in the maxilla and the mandible. Aesthetic and social evaluation were positive. We have restored the normal oro-facial functions for the correct development of skeletal bases. They acted as an external fixator intraoral, stimulating the growth by the function. Our question was: can we leave a child throughout his childhood and adolescence with a not suitable removable prosthesis, under the pretext of growth unfinished?展开更多
Dental abnormalities associated with specific syndromes and/or severesystemic abnormalities in tooth number, form or size are challenging cases in dentistry, affectingesthetics and function. Microdontia is used to ter...Dental abnormalities associated with specific syndromes and/or severesystemic abnormalities in tooth number, form or size are challenging cases in dentistry, affectingesthetics and function. Microdontia is used to term abnormally small teeth that generally themaxillary lateral incisor or third molar is involved. On the other hand, the entire dentition may beaffected as well. Prevalence of microdontia range from 1.5% - 2%. The definition of severehypodontia is four or more tacking teeth. The prevalence of severe hypodontia was found to be lessthan 1% of the unselected population. In another study hypodontia is seen with a higher incidence inthe permanent dentition (3.5% - 6.5%), compared to that of the primary one (0.1% - 0.9%). Theetiology seems to be inheritance in most cases of hypodontia. However, some are caused by mechanicaltrauma to jaws during tooth formation, by infection or by the effects of cytostatica and radiationduring cancer treatment. There are more than 160 syndromes combined with hypodontia. Some of themare ectodermal dysplasia, Rieger syndrome and incontinentia pigmenti. In such cases morphologicalaberrancies as microdontia and conical crowns may be additional features. In addition to the numberof lacking teeth, tooth eruption, occlusion and craniofacial parameters are influenced. The presentpaper reports the use of maxillary and mandibular overdenture removable complete dentures to treat apatient with class III skeletal malocclusion, reduced vertical dimension of occlusion andunacceptable esthetics caused by a rare case of hypodontia and microdontia.展开更多
选择性先天缺牙是由遗传或环境因素导致的牙齿数目异常,多累及恒牙列。低密度脂蛋白受体相关蛋白6(low-density lipoprotein receptor-related protein 6,LRP6)是选择性先天缺牙的常见致病基因之一,该基因突变为常染色体显性遗传,可导...选择性先天缺牙是由遗传或环境因素导致的牙齿数目异常,多累及恒牙列。低密度脂蛋白受体相关蛋白6(low-density lipoprotein receptor-related protein 6,LRP6)是选择性先天缺牙的常见致病基因之一,该基因突变为常染色体显性遗传,可导致非综合征型先天缺牙或综合征型先天缺牙;非综合征型先天缺牙仅表现为牙齿数目、形态异常;综合征型先天缺牙可表现为耳部发育畸形、口面裂、毛发稀少、汗腺异常等。笔者就近年来关于LRP6基因突变导致选择性先天缺牙的表型及基因突变特点的研究现况进行综述,文献收纳24个LRP6基因突变位点和38例相关先天缺牙患者,发现LRP6基因突变导致的选择性先天缺牙好发于上颌侧切牙及上下颌第二前磨牙和第一前磨牙,极少发生于第一磨牙,尤其是下颌第一磨牙,未见上颌中切牙缺失。LRP6基因在牙发育过程中主要通过WNT/β-catenin信号通路发挥重要作用,LRP6基因突变可导致蛋白表达和功能异常、信号通路破坏从而导致选择性先天缺牙。现有文献结果显示,LRP6基因突变好发于胞外段E1、E2亚结构域,影响WNT/β-catenin信号通路的传导而致病。然而目前对于选择性先天缺牙仍缺乏成熟完善的对因治疗。展开更多
The aim of this study was to investigate and compare the inheritance pattern and prevalence of inheritable dental anomalies in a sample of patients with maxillary canine—first premolar transposition and their first-d...The aim of this study was to investigate and compare the inheritance pattern and prevalence of inheritable dental anomalies in a sample of patients with maxillary canine—first premolar transposition and their first-degree relatives with a sample of palatally displaced canine families. Thirty-five consecutive maxillary canine—first premolar transposition probands and 111 first-degree relatives were matched to 35 consecutive palatally displaced canine probands and 115 first-degree relatives. These were assessed for palatally displaced canines and incisor-premolar hypodontia. Parental age at birth of the proband was also noted. The results revealed that（i） there is no difference in the overall prevalence of palatally displaced canine or incisor-premolar hypodontia between the groups of relatives;（ii） first-degree relatives of bilateral palatally displaced canine probands have a higher prevalence of palatally displaced canine and incisor-premolar hypodontia than those with unilateral palatally displaced canine; and（iii） maternal age at birth of the maxillary canine—first premolar transposition probands was significantly higher than that of the palatally displaced canine probands.The results suggest that maxillary canine—first premolar transposition and palatally displaced canine are unlikely to be different genetic entities and also indicate environmental or epigenetic influences on dental development.展开更多
Abnormalities of tooth number in development of the dentition are quite common;however, concomitant hypo-hyperdontia is a rare mixed numeric anomalous condition, especially when it occurs in the same dental arch and i...Abnormalities of tooth number in development of the dentition are quite common;however, concomitant hypo-hyperdontia is a rare mixed numeric anomalous condition, especially when it occurs in the same dental arch and in a non-syndromic situation. The presence of this condition specifically in the mandibular anterior region is reported very infrequently. This case report presents the case of a 9 years old non-syndromic male with missing mandibular central incisors and an erupted mandibular mesiodens along with the review of literature. To ensure optimum function and aesthetics, cosmetic recontouring was performed after oral prophylaxis. This is the ninth case reported in the dental literature till date, with the two anomalies manifesting in the anterior region of the mandible. This article also discusses the review of literature of concomitant hypo-hyperdontia.展开更多
Tooth agenesis is the most common developmental anomaly of the human dentition. Epilepsy-like disorder (EL) mice, which have a 100% incidence of agenesis of the third molars, may be a good model for the genetic study ...Tooth agenesis is the most common developmental anomaly of the human dentition. Epilepsy-like disorder (EL) mice, which have a 100% incidence of agenesis of the third molars, may be a good model for the genetic study of human tooth agenesis. Our previous congenic breeding strategy using EL mice confined a major locus for agenesis of M3, designated am3, within an approximately 1 Mega base pair (Mbp) interval on chromosome 3, which contains five known genes;Lef1, Hadh, Cyp2u1, Sgms2 and Papss1. The aim of this study was to identify the strongest candidate for am3 among the five genes using real-time PCR analysis. The tooth germs of M3 in the bud stage of EL and control mice were dissected out, and total RNA was extracted. In real-time PCR analysis, a significantly low level of expression of Lef1, which is one of the essential transcription factors for early tooth development, was observed in M3 of EL mice. In addition, a significantly low level of expression of Fgf4, which is a direct transcriptional target for LEF1 in early tooth development, was observed in M3 of EL mice. Our results suggest that the cause of M3 agenesis of EL mice may be a low level of Lef1 expression in M3 in the bud stage of EL mice.展开更多
Malignant neoplasms are one of the main causes of death in developed countries.Thanks to the multidisciplinary approach and treatments methods(surgical treatment,chemotherapy,radiotherapy)in pediatric oncology,the num...Malignant neoplasms are one of the main causes of death in developed countries.Thanks to the multidisciplinary approach and treatments methods(surgical treatment,chemotherapy,radiotherapy)in pediatric oncology,the number of cancer survivors among children is growing.The high survival rate obliges the medical community to monitor the long-term consequences of both the cancer disease and the anticancer treatment used.The incidence and type of complications in oncological treatment vary.Their presence and severity depend on the child‟s age,the nature of the malignant neoplasm,as well as the specificity and intensity of therapy.Frequent complications of treatment may include serious maxillofacial defects resulting from developmental disorders of bones,soft tissues and teeth.One of the dental complications of both radio-and chemotherapy is tooth agenesis.In this manuscript,we highlight the dental complications of oncological treatment and the need of an interdisciplinary approach in dealing with them.展开更多
文摘Hypodontia is defined as the developmental absence of one or more teeth which can affect both the primary and permanent dentition. During the diagnosis procedure several other dental and oral symptoms can be observed. However esthetic and psychological problems require special attention for these patients, considering that they are often associated with low self-esteem and problems of social acceptance. The optimal therapy should include an interdisciplinary team approach. This review aimed to find out prevalence, causes, clinical manifestations, and treatment modalities of hypodontia. A case report describes that the treatment planning for a patient suffering from oligodontia is introduced at the end of the review. A specialist with the patient together made the decision regarding treatment.
文摘The ectodermal dysplasias are rare diseases with hypodontia, hypotrichosis and hypohidrosis. The subject's life is considerably constrained and this from an early age, with major difficulties for the integration and acceptance of conventional prosthetic occlusal rehabilitation. The use of implants is an integral part of early treatment, in the regions of stable growth, that is to say symphysis. In two childs of 5 and 6 years we have made implant-borne prosthetic rehabilitation in the maxilla and the mandible. Aesthetic and social evaluation were positive. We have restored the normal oro-facial functions for the correct development of skeletal bases. They acted as an external fixator intraoral, stimulating the growth by the function. Our question was: can we leave a child throughout his childhood and adolescence with a not suitable removable prosthesis, under the pretext of growth unfinished?
文摘Dental abnormalities associated with specific syndromes and/or severesystemic abnormalities in tooth number, form or size are challenging cases in dentistry, affectingesthetics and function. Microdontia is used to term abnormally small teeth that generally themaxillary lateral incisor or third molar is involved. On the other hand, the entire dentition may beaffected as well. Prevalence of microdontia range from 1.5% - 2%. The definition of severehypodontia is four or more tacking teeth. The prevalence of severe hypodontia was found to be lessthan 1% of the unselected population. In another study hypodontia is seen with a higher incidence inthe permanent dentition (3.5% - 6.5%), compared to that of the primary one (0.1% - 0.9%). Theetiology seems to be inheritance in most cases of hypodontia. However, some are caused by mechanicaltrauma to jaws during tooth formation, by infection or by the effects of cytostatica and radiationduring cancer treatment. There are more than 160 syndromes combined with hypodontia. Some of themare ectodermal dysplasia, Rieger syndrome and incontinentia pigmenti. In such cases morphologicalaberrancies as microdontia and conical crowns may be additional features. In addition to the numberof lacking teeth, tooth eruption, occlusion and craniofacial parameters are influenced. The presentpaper reports the use of maxillary and mandibular overdenture removable complete dentures to treat apatient with class III skeletal malocclusion, reduced vertical dimension of occlusion andunacceptable esthetics caused by a rare case of hypodontia and microdontia.
文摘选择性先天缺牙是由遗传或环境因素导致的牙齿数目异常,多累及恒牙列。低密度脂蛋白受体相关蛋白6(low-density lipoprotein receptor-related protein 6,LRP6)是选择性先天缺牙的常见致病基因之一,该基因突变为常染色体显性遗传,可导致非综合征型先天缺牙或综合征型先天缺牙;非综合征型先天缺牙仅表现为牙齿数目、形态异常;综合征型先天缺牙可表现为耳部发育畸形、口面裂、毛发稀少、汗腺异常等。笔者就近年来关于LRP6基因突变导致选择性先天缺牙的表型及基因突变特点的研究现况进行综述,文献收纳24个LRP6基因突变位点和38例相关先天缺牙患者,发现LRP6基因突变导致的选择性先天缺牙好发于上颌侧切牙及上下颌第二前磨牙和第一前磨牙,极少发生于第一磨牙,尤其是下颌第一磨牙,未见上颌中切牙缺失。LRP6基因在牙发育过程中主要通过WNT/β-catenin信号通路发挥重要作用,LRP6基因突变可导致蛋白表达和功能异常、信号通路破坏从而导致选择性先天缺牙。现有文献结果显示,LRP6基因突变好发于胞外段E1、E2亚结构域,影响WNT/β-catenin信号通路的传导而致病。然而目前对于选择性先天缺牙仍缺乏成熟完善的对因治疗。
基金funded under the Joint King’s College London/University of Malta agreement
文摘The aim of this study was to investigate and compare the inheritance pattern and prevalence of inheritable dental anomalies in a sample of patients with maxillary canine—first premolar transposition and their first-degree relatives with a sample of palatally displaced canine families. Thirty-five consecutive maxillary canine—first premolar transposition probands and 111 first-degree relatives were matched to 35 consecutive palatally displaced canine probands and 115 first-degree relatives. These were assessed for palatally displaced canines and incisor-premolar hypodontia. Parental age at birth of the proband was also noted. The results revealed that（i） there is no difference in the overall prevalence of palatally displaced canine or incisor-premolar hypodontia between the groups of relatives;（ii） first-degree relatives of bilateral palatally displaced canine probands have a higher prevalence of palatally displaced canine and incisor-premolar hypodontia than those with unilateral palatally displaced canine; and（iii） maternal age at birth of the maxillary canine—first premolar transposition probands was significantly higher than that of the palatally displaced canine probands.The results suggest that maxillary canine—first premolar transposition and palatally displaced canine are unlikely to be different genetic entities and also indicate environmental or epigenetic influences on dental development.
文摘Abnormalities of tooth number in development of the dentition are quite common;however, concomitant hypo-hyperdontia is a rare mixed numeric anomalous condition, especially when it occurs in the same dental arch and in a non-syndromic situation. The presence of this condition specifically in the mandibular anterior region is reported very infrequently. This case report presents the case of a 9 years old non-syndromic male with missing mandibular central incisors and an erupted mandibular mesiodens along with the review of literature. To ensure optimum function and aesthetics, cosmetic recontouring was performed after oral prophylaxis. This is the ninth case reported in the dental literature till date, with the two anomalies manifesting in the anterior region of the mandible. This article also discusses the review of literature of concomitant hypo-hyperdontia.
文摘Tooth agenesis is the most common developmental anomaly of the human dentition. Epilepsy-like disorder (EL) mice, which have a 100% incidence of agenesis of the third molars, may be a good model for the genetic study of human tooth agenesis. Our previous congenic breeding strategy using EL mice confined a major locus for agenesis of M3, designated am3, within an approximately 1 Mega base pair (Mbp) interval on chromosome 3, which contains five known genes;Lef1, Hadh, Cyp2u1, Sgms2 and Papss1. The aim of this study was to identify the strongest candidate for am3 among the five genes using real-time PCR analysis. The tooth germs of M3 in the bud stage of EL and control mice were dissected out, and total RNA was extracted. In real-time PCR analysis, a significantly low level of expression of Lef1, which is one of the essential transcription factors for early tooth development, was observed in M3 of EL mice. In addition, a significantly low level of expression of Fgf4, which is a direct transcriptional target for LEF1 in early tooth development, was observed in M3 of EL mice. Our results suggest that the cause of M3 agenesis of EL mice may be a low level of Lef1 expression in M3 in the bud stage of EL mice.
文摘Malignant neoplasms are one of the main causes of death in developed countries.Thanks to the multidisciplinary approach and treatments methods(surgical treatment,chemotherapy,radiotherapy)in pediatric oncology,the number of cancer survivors among children is growing.The high survival rate obliges the medical community to monitor the long-term consequences of both the cancer disease and the anticancer treatment used.The incidence and type of complications in oncological treatment vary.Their presence and severity depend on the child‟s age,the nature of the malignant neoplasm,as well as the specificity and intensity of therapy.Frequent complications of treatment may include serious maxillofacial defects resulting from developmental disorders of bones,soft tissues and teeth.One of the dental complications of both radio-and chemotherapy is tooth agenesis.In this manuscript,we highlight the dental complications of oncological treatment and the need of an interdisciplinary approach in dealing with them.
