Five mandibular incisors: an autosomal recessive trait?

Two Rare Cases of Non-Syndromic Paramolars with Family Occurrence and a Review of Literature

Supernumerary teeth (or hyperdontia) are teeth that exceed the normal number of deciduous or permanent teeth in the oral cavity. The occurrence of supernumerary teeth without any associated syndrome has been frequently reported and many case reports have been published. This article reports two rare cases of familial occurrence of multiple paramolars without the presence of any other syndrome for two consecutive generations. Limited cases of bilateral maxillary or mandibular paramolars have been reported. In addition, prevalence, classification, etiology, complications, diagnosis and therapeutic strategies that may be adopted when supernumeraries occur are discussed. A review of similar cases published in the literature is included as well.

An Exploratory Study of Consanguinity and Dental Developmental Anomalies

Background

Consanguinity is known to alter the population structure but the available literature is almost silent on the association of dental conditions with consanguinity.

Aim

The purpose was to assess the various dental developmental anomalies in 6–9 year old children born out of consanguineous and non-consanguineous marriages and its association with their parents.

Design

A cross sectional house–hold survey with a sample size of 2,000 (1,600 non-consanguineous and 400 consanguineous respondents and their parents) using systematic random sampling was planned. Six to nine-year-old children and their parents living in 1,597 households were examined and the information recorded on a pretested self prepared questionnaire. The questionnaire had questions pertaining to personal details, type of consanguineous marriages, history of trauma and examination of dental developmental anomalies.

Results

Multivariate logistic regression showed that non syndromic supernumerary teeth in fathers (p =.009); fusion in mothers (p = 0.002); fusion (p <0.001), nonsyndromic supernumerary teeth (p < 0.001), and microdontia (p = 0.002) in respondents were significantly associated with consanguinity.

Conclusion

A significant association of developmental anomalies in parents with consanguineous marriages and their respondents was observed.

How to cite this article

Khan SY. An Exploratory Study of Consanguinity and Dental Developmental Anomalies. Int J Clin Pediatr Dent, 2018;11(6):513-518

The doppelganger tooth: A diagnostic conundrum!

Abnormalities in tooth morphology and number are not uncommon. However, an exact clone of a normal tooth is a recondite clinical finding. Presence of supplementary teeth is mostly noticed in maxillary anterior, molar or premolar region, followed by mandibular premolar region in descending order of its site of occurrence. Supplemental tooth in mandibular anterior has a low prevalence of 0.01%. This paper reports one such rare case of nonsyndromic incisive jumeaux in mandibular anterior region during mixed dentition period.

Supplemental mandibular mesiodens: a diagnostic challenge

Developmental anomalies affecting the number of teeth are occasionally encountered clinically. The incidence of supernumerary teeth is approximately 1-3%. Among these are the maxillary anterior teeth, the maxillary molars, and the maxillo-mandubular premolars, in terms of descending order of occurrence. Supernumeraries occur rarely in the mandibular anterior teeth region. They may be either supplemental or rudimentary. We are reporting case of a supplemental type of supernumerary tooth in the mandibular anterior region and steps which were followed to distinguish supernumerary tooth from the normal series.

Developmental disorders of the dentition: an update

Dental anomalies are common congenital malformations that can occur either as isolated findings or as part of a syndrome. This review focuses on genetic causes of abnormal tooth development and the implications of these abnormalities for clinical care. As an introduction, we describe general insights into the genetics of tooth development obtained from mouse and zebrafish models. This is followed by a discussion of isolated as well as syndromic tooth agenesis, including Van der Woude syndrome (VWS), ectodermal dysplasias (EDs), oral-facial-digital (OFD) syndrome type I, Rieger syndrome, holoprosencephaly, and tooth anomalies associated with cleft lip and palate. Next, we review delayed formation and eruption of teeth, as well as abnormalities in tooth size, shape, and form. Finally, isolated and syndromic causes of supernumerary teeth are considered, including cleidocranial dysplasia and Gardner syndrome.

Aetiology of supernumerary teeth: a literature review

BACKGROUND

Supernumerary teeth are teeth, or tooth-like structures that have either erupted or remain unerupted in addition to the 20 primary and 32 permanent teeth.

AIMS

This paper attempts to (a) provide an overview of the proposed hypotheses and the current understanding of the aetiology of supernumerary teeth, and (b) review the published cases of supernumerary teeth occurring in families.

REVIEW

No studies have been able to distinguish between different aetiologies for the different locations of supernumerary teeth, while, from a developmental or molecular perspective, the proposed hypotheses may be plausible and explains the origin of different types of supernumerary teeth.

CONCLUSION

The only clearly evident feature, based on the existing published reports, is that it is logical to state that supernumerary teeth have a genetic component in their aetiology.

Genetics and presence of non-syndromic supernumerary teeth: A mystery case report and review of literature

Presence of supernumerary teeth is well-recognized clinical phenomenon. However, it is uncommon to find multiple supernumeraries in individuals with no other associated disease or syndrome. Presence of multiple supernumerary teeth is thought to have genetic component. We report a rare case where multiple supernumerary teeth were seen without presence of any other syndrome in 3 generations; father, son, and two grandsons. We also present a review of similar cases published in literature till date. The role of genetics in development of supernumerary teeth is highlighted.

Genetic basis of non-syndromic anomalies of human tooth number

Teeth organogenesis develops through a well-ordered series of inductive events involving genes and BMP, FGF, SHH and WNT represent the main signalling pathways that regulate epithelial-mesenchymal interactions. Moreover, progress in genetics and molecular biology indicates that more than 300 genes are involved in different phases of teeth development. Mutations in genes involved in odontogenesis are responsible for many dental anomalies, including a number of dental anomalies that can be associated with other systemic skeletal or organic manifestations (syndromic dental anomalies) or not (non-syndromic dental anomalies). The knowledge of the genetic development mechanisms of the latter is of major interest. Understanding the mechanisms of pathogenesis of non-syndromic teeth anomalies would also clarify the role of teeth in craniofacial development, and this would represent an important contribution to the diagnosis, treatment and prognosis of congenital malformations, and the eventual association to other severe diseases. Future research in this area is likely to lead to the development of tests for doctors to formulate an early diagnosis of these anomalies.

Supernumerary eumorphic mandibular incisor in association with aggressive periodontitis

According to the literature, the prevalence of supernumerary teeth is 1% to 4% of permanent dentitions; and among these, the presence of fifth mandibular incisor — a supernumerary eumorphic tooth — has rarely been described in literature, and its association with localized aggressive periodontitis is an even more rare entity. This paper reports a very rare case of unusual association of supernumerary eumorphic fifth mandibular incisor with aggressive periodontitis in a Muslim individual, so that these findings generate curiosity and inspire others to carry out further studies and investigations.

Is the homozygous region on chromosome 16q12.2 responsible for a fifth mandibular incisor?

The presence of a fifth mandibular incisor, a eumorphic supernumerary tooth, has rarely been described in the literature. Recently we reported on a large Lebanese consanguineous family where 4 individuals displayed 5 mandibular incisors with the same shape and size. This type of familial clustering of the trait has not been previously described. We previously postulated several theories to explain the etiology of this anomaly. The possibility of an autosomal recessive inheritance for this nonsyndromic trait was discussed. We now report the use of homozygosity mapping to identify a homozygous region with different alleles at chromosome 16q12.2, located at the marker D16S415, which likely harbors the gene underlying this anomaly.

Supplemental mandibular permanent incisor teeth: report of two cases

Two cases of supplemental mandibular permanent incisors are presented. These supernumerary teeth often erupt into the dental arches causing crowding and aesthetic problems. Management may range from simple extraction of the supernumerary teeth to comprehensive orthodontic treatment. Early diagnosis may provide better opportunity for optimal treatment outcome.