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
牙齿数目异常是口腔常见疾病,可表现为牙齿数目过多(多生牙)和牙齿数目不足(先天缺牙),2种情况可单独发生,也可在同一个体中同时发生。Camilleri将这种既有多生牙又先天缺牙的疾病称为少牙多牙症(comcomitant hypodontia and hyperdonti...牙齿数目异常是口腔常见疾病,可表现为牙齿数目过多(多生牙)和牙齿数目不足(先天缺牙),2种情况可单独发生,也可在同一个体中同时发生。Camilleri将这种既有多生牙又先天缺牙的疾病称为少牙多牙症(comcomitant hypodontia and hyperdontia,CHH),CHH是一种较为少见的疾病。目前病因不明确,患病率差异较大,男性发病率高于女性。可伴发多种综合征和其他牙齿异常等。目前关于CHH的研究多以病例报道为主,本文综合国内外的相关研究,对其病因、临床表现、诊断、影响和治疗原则作一综述。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
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
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
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.
文摘牙齿数目异常是口腔常见疾病,可表现为牙齿数目过多(多生牙)和牙齿数目不足(先天缺牙),2种情况可单独发生,也可在同一个体中同时发生。Camilleri将这种既有多生牙又先天缺牙的疾病称为少牙多牙症(comcomitant hypodontia and hyperdontia,CHH),CHH是一种较为少见的疾病。目前病因不明确,患病率差异较大,男性发病率高于女性。可伴发多种综合征和其他牙齿异常等。目前关于CHH的研究多以病例报道为主,本文综合国内外的相关研究,对其病因、临床表现、诊断、影响和治疗原则作一综述。
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.
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.
