Non-syndromic multiple supernumerary teeth: report of a case with 14 supplemental teeth.

Indian J Dent Res. 2007 Jul-Sep;18(3):144

Authors: Sivapathasundharam B, Einstein A

PMID: 17687181 [PubMed - indexed for MEDLINE]

Mesiodens with an unusual morphology and multiple impacted supernumerary teeth in a non-syndromic patient.

Indian J Dent Res. 2007 Jul-Sep;18(3):138-40

Authors: Srivatsan P, Aravindha Babu N

Supernumerary teeth are a relatively frequent disorder of odontogenesis characterized by an excess number of teeth. Mesiodens is the most common type of supernumerary tooth found in the premaxilla between the two central incisors. They can be supplemental (resembling natural teeth), conical, tuberculate or molariform. We present the case of a 19 year-old girl who presented with a mesiodens of an unusual morphology and multiple impacted supernumerary teeth not associated with any syndrome.

PMID: 17687179 [PubMed - indexed for MEDLINE]

A novel DSPP mutation is associated with type II dentinogenesis imperfecta in a Chinese family.

BMC Med Genet. 2007;8:52

Authors: Zhang X, Chen L, Liu J, Zhao Z, Qu E, Wang X, Chang W, Xu C, Wang QK, Liu M

BACKGROUND: Hereditary defects of tooth dentin are classified into two main groups: dentin dysplasia (DD) (types I and II) and dentinogenesis imperfecta (DGI) (types I, II, and III). Type II DGI is one of the most common tooth defects with an autosomal dominant mode of inheritance. One disease-causing gene, the dentin sialophosphoprotein (DSPP) gene, has been reported for type II DGI. METHODS: In this study, we characterized a four-generation Chinese family with type II DGI that consists of 18 living family members, including 8 affected individuals. Linkage analysis with polymorphic markers D4S1534 and D4S414 that span the DSPP gene showed that the family is linked to DSPP. All five exons and exon-intron boundaries of DSPP were sequenced in members of type II DGI family. RESULTS: Direct DNA sequence analysis identified a novel mutation (c.49C-->T, p.Pro17Ser) in exon 1 of the DSPP gene. The mutation spot, the Pro17 residue, is the second amino acid of the mature DSP protein, and highly conserved during evolution. The mutation was identified in all affected individuals, but not in normal family members and 100 controls. CONCLUSION: These results suggest that mutation p.Pro17Ser causes type II DGI in the Chinese family. This study identifies a novel mutation in the DSPP gene, and expands the spectrum of mutations that cause DGI.

PMID: 17686168 [PubMed - indexed for MEDLINE]

Dens invaginatus on a geminated tooth: a case report.

J Contemp Dent Pract. 2007;8(5):99-105

Authors: Canger EM, Celenk P, Sezgin OS

AIM: To present a case of a concomitant occurrence of dens invaginatus (DI) and gemination in a mandibular left lateral incisor. BACKGROUND: DI is a developmental anomaly resulting from the invagination of a portion of a crown in the enamel organ stage of odontogenesis. It is commonly found in the maxillary lateral incisors but also occurs in the central incisors, premolars, canines, and molars in descending order of frequency. The occurrence of DI in the mandible is extremely rare. Gemination results from one tooth bud attempting to split into two. Geminated teeth present with a single root structure and rarely occur in mandibular teeth. REPORT: A 13-year-old girl presented with a chief complaint of spontaneous nocturnal pain in the mandibular left lateral incisor tooth. Intraoral examination revealed the tooth was enlarged with a notch on the incisal edge extending to the coronal 1/3 of the crown. The radiological examination revealed a Type 2 DI in a Type I geminated mandibular left lateral incisor. SUMMARY: DI is clinically significant due to the possibility of the pulpal involvement; pulpitis, necrotic pulps, and chronic periapical lesions are often associated with this anomaly without clinical symptoms. Clinicians should be mindful of the possibility of DI when a tooth presents pulpitis without history of trauma or caries and examine the suspicious tooth and the periodontium radiographically.

PMID: 17618336 [PubMed - indexed for MEDLINE]

Congenital hypotrichosis and partial anodontia in a crossbred beef calf.

Can Vet J. 2007 Jun;48(6):612-4

Authors: Barlund CS, Clark EG, Leeb T, Drögemüller C, Palmer CW

Clinical examination, skin biopsies, skull radiographs, and DNA analysis of a 2-day-old Red Angus-Charolais-Simmental cross bull calf confirmed the diagnosis of congenital hypotrichosis and anodontia defect (HAD), also called anhidrotic ectodermal dysplasia, which is a rare anomaly caused by a deletion in the bovine EDA gene on the X chromosome.

PMID: 17616058 [PubMed - indexed for MEDLINE]

Acro-dermato-ungual-lacrimal-tooth syndrome: case report.

Chin Med J (Engl). 2007 May 5;120(9):851-3

Authors: Yang J, Zhang HJ, Yang WL, Chen GS, Tang ZW, Chen S, Ye WH

PMID: 17531133 [PubMed - indexed for MEDLINE]

Root development of permanent lateral incisor in cleft lip and palate children: a radiographic study.

Indian J Dent Res. 2007 Apr-Jun;18(2):82-6

Authors: Deepti A, Muthu MS, Kumar NS

OBJECTIVE: The objective of this study was to compare the root development of lateral incisor on the cleft side with the root development of its contralateral tooth in cleft lip and palate children. SETTING: Cleft lip and palate wing, Meenakshi Ammal Dental College and Hospital, Chennai, South India. MATERIALS AND METHODS: A sample of 96 orthopantamograms of patients with unilateral orbilateral cleft lip and/or cleft palate was selected, regardless of sex and race. MAIN OUTCOME MEASURE: Orthopantamograms were analyzed for root development of lateral incisor on the cleft and non cleft side. Associated anomalies like hypodontia, supernumerary teeth, malformed lateral incisors and root development of canine, if present, were recorded. FINDINGS AND CONCLUSIONS: Root development of permanent lateral incisor was delayed on the cleft side compared to the non cleft side. There was a statistically significant relationship between levels of root development of lateral incisors on the cleft side within the different study groups(P < 0.05). Incidence of hypodontia increased in proportion to cleft severity. Frequency of missing second premolars, supernumerary teeth and malformed lateral incisors increased in cleft lip and palate patients. Root development of canine showed a slight delay on the cleft side when compared to the canine on the noncleft side.

PMID: 17502714 [PubMed - indexed for MEDLINE]

Restoring function and esthetics in a patient with amelogenesis imperfecta: a case report.

J Contemp Dent Pract. 2007;8(4):95-101

Authors: Gokce K, Canpolat C, Ozel E

AIM: The purpose of this case report is to present the esthetic and functional rehabilitation of the teeth in a 22-year-old patient with Amelogenesis imperfecta (AI). BACKGROUND: AI is a group of hereditary defects of enamel, unassociated with any other generalized defects. It is a rare developmental abnormality of the enamel, with a variable occurrence of approximately 1:4000 to 1:14000 in Western populations. Al results in poor development or complete absence of the enamel of the teeth caused by improper differentiation of the ameloblasts. REPORT: This report describes the diagnosis and treatment of a young male patient with AI and missing molar teeth using contemporary restorative strategies. Initially, the tooth surfaces were treated with a professional cleaning along with conservative restorative treatment. Later, metal-ceramic crowns for posterior teeth and full-ceramic crowns for anterior teeth were utilized for final restorations. SUMMARY: The complexity of the management of patients with AI supports the suggestion the dental profession should have appropriate methods for the rehabilitation of rare dental disorders. The treatment of patients with AI should start with early diagnosis and intervention to prevent later restorative problems.

PMID: 17486193 [PubMed - indexed for MEDLINE]

Non-syndrome multiple supernumerary teeth: A case report.

J Contemp Dent Pract. 2007;8(4):81-7

Authors: G&#xFC;ndüz K, Muğlali M

AIM: The purpose of this case report is to present a case of a non-syndrome male patient with multiple supplemental supernumerary teeth in three quadrants of his mouth. BACKGROUND: Supernumerary teeth are described as the teeth formed in excess of the number found in a normal dentition. Prevalence of supernumerary teeth varies between 0.1% and 3.8% in the general Caucasian population. Multiple supernumerary teeth are not a common occurrence, although a single or a few supernumerary tooth/teeth in each case have been widely reported in the literature. REPORT: An 11-year-old male presented for a routine preventive dental visit. A routine panoramic radiograph showed the presence of multiple supernumerary teeth which were located in the maxillary right canine incisor region, the maxillary left premolar region, and the mandibular right premolar region. The family's medical history was non-contributory, and an extraoral examination did not reveal any abnormality. SUMMARY: It is rare to find multiple supernumerary teeth in individuals with no other associated diseases or syndromes. This case report presents a case of a non-syndrome male patient with multiple supplemental supernumerary teeth in three quadrants of his mouth.

PMID: 17486191 [PubMed - indexed for MEDLINE]

Dentigerous cyst associated with multiple mesiodens: a case report.

J Indian Soc Pedod Prev Dent. 2007 Mar;25(1):56-9

Authors: Dinkar AD, Dawasaz AA, Shenoy S

Dentigerous cyst is a developmental odontogenic cyst, which apparently develops by accumulation of fluid between reduced enamel epithelium and the tooth crown of an unerupted tooth. When observed with erupted and complete dentition the diagnosis is a surprise; as about 95% of dentigerous cysts involve the permanent dentition and only 5% are associated with supernumerary teeth. The usual age of clinical presentation of dentigerous cyst due to supernumerary tooth is during the first four decades. Mesiodens is a supernumerary tooth situated between the maxillary central incisors. More frequently the mesiodens occurs unilaterally, but it may also be bilateral, while three or more supernumerary teeth in the median region of the palate are more rarely found. We report a rare case of dentigerous cyst in association with multiple mesiodens in a 14-year-old female patient.

PMID: 17456972 [PubMed - indexed for MEDLINE]

Clinical and intraoral findings of a patient with tricho-rhino-phalangeal syndrome type I.

J Indian Soc Pedod Prev Dent. 2007 Mar;25(1):43-5

Authors: Karacay S, Saygun I, Tunca Y, Imirzalioglu N, Guvenc G

Tricho-rhino-phalangeal syndrome (TRPS) is a rare and an autosomal dominant disorder having the following characteristics: slowly growing sparse hair, medially thick and laterally thin eyebrows, bulbous tip of the nose, long flat philtrum and thin upper lip with vermilion border, protruding ears, cone-shaped epiphyses and swelling. Our report intends to introduce TRPS to the dental literature and to present oral, clinical and radiological data of a patient with TRPS. A rare association of supernumerary teeth was also diagnosed and one of them was extracted as it impeded on the eruption path of left premolar tooth.

PMID: 17456968 [PubMed - indexed for MEDLINE]

Identification of three novel NHS mutations in families with Nance-Horan syndrome.

Mol Vis. 2007;13:470-4

Authors: Huang KM, Wu J, Brooks SP, Hardcastle AJ, Lewis RA, Stambolian D

PURPOSE: Nance-Horan Syndrome (NHS) is an infrequent and often overlooked X-linked disorder characterized by dense congenital cataracts, microphthalmia, and dental abnormalities. The syndrome is caused by mutations in the NHS gene, whose function is not known. The purpose of this study was to identify the frequency and distribution of NHS gene mutations and compare genotype with Nance-Horan phenotype in five North American NHS families. METHODS: Genomic DNA was isolated from white blood cells from NHS patients and family members. The NHS gene coding region and its splice site donor and acceptor regions were amplified from genomic DNA by PCR, and the amplicons were sequenced directly. RESULTS: We identified three unique NHS coding region mutations in these NHS families. CONCLUSIONS: This report extends the number of unique identified NHS mutations to 14.

PMID: 17417607 [PubMed - indexed for MEDLINE]

Amelogenesis imperfecta.

Orphanet J Rare Dis. 2007;2:17

Authors: Crawford PJ, Aldred M, Bloch-Zupan A

Amelogenesis imperfecta (AI) represents a group of developmental conditions, genomic in origin, which affect the structure and clinical appearance of enamel of all or nearly all the teeth in a more or less equal manner, and which may be associated with morphologic or biochemical changes elsewhere in the body. The prevalence varies from 1:700 to 1:14,000, according to the populations studied. The enamel may be hypoplastic, hypomineralised or both and teeth affected may be discoloured, sensitive or prone to disintegration. AI exists in isolation or associated with other abnormalities in syndromes. It may show autosomal dominant, autosomal recessive, sex-linked and sporadic inheritance patterns. In families with an X-linked form it has been shown that the disorder may result from mutations in the amelogenin gene, AMELX. The enamelin gene, ENAM, is implicated in the pathogenesis of the dominant forms of AI. Autosomal recessive AI has been reported in families with known consanguinity. Diagnosis is based on the family history, pedigree plotting and meticulous clinical observation. Genetic diagnosis is presently only a research tool. The condition presents problems of socialisation, function and discomfort but may be managed by early vigorous intervention, both preventively and restoratively, with treatment continued throughout childhood and into adult life. In infancy, the primary dentition may be protected by the use of preformed metal crowns on posterior teeth. The longer-term care involves either crowns or, more frequently these days, adhesive, plastic restorations.

PMID: 17408482 [PubMed - indexed for MEDLINE]

Anesthetic management of the trigeminocardiac reflex during mesiodens removal-a case report.

Anesth Prog. 2007;54(1):7-8

Authors: Webb MD, Unkel JH

We describe a case in which reflection of a palatal flap for removal of a mesiodens is presented as the triggering factor for bradycardia caused by stimulation of the trigeminocardiac reflex. The management of the case, as well as the reflex arc, is discussed.

PMID: 17352528 [PubMed - indexed for MEDLINE]

Chondroectodermal dysplasia (Ellis van Creveld syndrome): a report of three cases with review of literature.

Indian J Dent Res. 2007 Jan-Mar;18(1):31-4

Authors: Kurian K, Shanmugam S, Harsh Vardah T, Gupta S

Chondroectodermal dysplasia is a rare mesenchymal - ectodermal dysplasia first described in 1940 by Richard W.B. Ellis and Simon van Creveld now known as Ellis van Creveld syndrome. It is also known as Mesvectodermal dysplasia. Majority of cases were characteristically seen in one particular inbred population from the Amish community of Lancaster County, Pennsylvania, U.S.A. The syndrome manifests with several skeletal anomalies, oral mucosal and dental anomalies, congenital cardiac defects and nail dysplasia. Ellis van Creveld syndrome may be differentiated from other chondrodystrophies like achondroplasia, chondroplasia punctata, asphyxiating thorasic dystrophy and Morquio's syndrome. The presence of oral mucosal and dental alterations like notching of the lower alveolar process, fusion of the upper lip with gingival mucosal margin, occasional presence of neonatal teeth, oligodontia and conical shape of anterior teeth will confirm the diagnosis of Ellis van Creveld syndrome and hence its importance to dentists.

PMID: 17347543 [PubMed - indexed for MEDLINE]

An observational study of the frequency of supernumerary teeth in a population of 2000 patients.

Med Oral Patol Oral Cir Bucal. 2007 Mar;12(2):E134-8

Authors: Leco Berrocal MI, Mart&#xED;n Morales JF, Martínez González JM

OBJECTIVES: An evaluation is made of the epidemiological characteristics of supernumerary teeth, with an analysis of the associated clinical-eruptive complications. STUDY DESIGN: A longitudinal observational study was made of 2000 patients, with the documentation of demographic data, the presence of supernumerary teeth, their location, mechanical accidents and the presence of associated pathology. RESULTS: The presence of supernumerary teeth was recorded in 1.05% of the study subjects (mean age 20.2 years), with a greater frequency in males. The most frequent location was in the upper maxilla (79.2%), fundamentally in the retromolar zone and at premaxillary level. The presence of mechanical accidents was the most frequent complication (54%)--the displacement of adjacent teeth being the most common finding--along with the presence of follicular cysts. CONCLUSIONS: The prevalence of supernumerary teeth in our series was 1.05%, the most frequent location being at upper distomolar level. Mechanical accidents were the most frequent complication.

PMID: 17322802 [PubMed - indexed for MEDLINE]

EEC syndrome sans clefting: variable clinical presentations in a family.

Indian J Dermatol Venereol Leprol. 2007 Jan-Feb;73(1):46-8

Authors: Thakkar S, Marfatia Y

Ectrodactyly, ectodermal dysplasia and cleft palate/lip syndrome (EEC) is a rare autosomal dominant syndrome with varied presentation and is actually a multiple congenital anomaly syndrome leading to intra- and interfamilial differences in severity because of its variable expression and reduced penetrance. The cardinal features include ectrodactyly, sparse, wiry, hypopigmented hair, peg-shaped teeth with defective enamel and cleft palate/lip. A family comprising father, daughter and son presented to us with split hand-split foot deformity (ectrodactyly), epiphora, hair changes and deafness with variable involvement in each family member.

PMID: 17314449 [PubMed - indexed for MEDLINE]

Bone grafting with platelet-rich plasma in alveolar cleft. Case report.

Minerva Stomatol. 2007 Jan-Feb;56(1-2):63-71

Authors: Rullo R, Festa VM, Guida L, Laino G

Bone grafting of the alveolus has become an essential part of the contemporary surgical management of oral clefts. The benefits of this procedure are the stabilization of the maxillary arch, elimination of oronasal fistulae, the reconstruction of the soft tissue nasal base support, creation of bony support for subsequent tooth eruption or, when they are not present or not preserved, for implants application. The authors show a case of bone grafting with the aid of platelet-rich plasma (PRP). Because of the difficulties due to the oral cleft and to its surgical reparation (big size of bone defect, hard scars and sclerotic soft tissue) the authors decided to add PRP to a bone graft taken from the chin. PRP contains a high concentration of growth factors and is able to stimulate both wound and bone regeneration. Infact, the authors have observed very good results both in bone integration and in soft tissue reparation.

PMID: 17287708 [PubMed - indexed for MEDLINE]

An unusual case of talon cusp on a geminated tooth.

Braz Dent J. 2006;17(4):343-6

Authors: G&#xFC;ndüz K, Açikgõz A

Talon cusp is a developmental anomaly seen on the lingual surface of anterior teeth. Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development. These developmental anomalies may cause clinical problems including esthetic impairment, pain, caries and tooth crowding. This paper presents an unusual case of gemination accompanied by talon cusp in permanent dentition. The clinical and radiographic findings are described.

PMID: 17262150 [PubMed - indexed for MEDLINE]

Dental findings in GAPO syndrome: case report.

Braz Dent J. 2006;17(3):259-62

Authors: da Silveira HE, Quadros OF, Dalla-Bona RR, da Silveira HL, Fritscher GG

This article reports the case of a young female adult with GAPO syndrome who presented as a peculiar dental finding unerupted primary and permanent dentitions, which resembled total anodontia on clinical examination. A cephalometric analysis was performed to investigate the alterations in facial bone development. This is the 9th GAPO syndrome case reported in a Brazilian patient.

PMID: 17262136 [PubMed - indexed for MEDLINE]

Kabuki make-up (Niikawa-Kuroki) syndrome: dental and craniofacial findings in a Brazilian child.

Braz Dent J. 2006;17(3):249-54

Authors: dos Santos BM, Ribeiro RR, Stuani AS, de Paula e Silva FW, de Queiroz AM

This article reports the case of a Brazilian child diagnosed with Kabuki make-up syndrome (KMS), addressing the clinical features observed, with emphasis on the disease-specific oral and craniofacial manifestations. The patient had the distinctive KMS craniofacial appearance, mild delayed mental development, fingers with prominent fingertip pads and visual deficit. The dental findings included fusion of the left mandibular incisors (central and lateral), gemination of the right mandibular central incisor and congenital agenesis of the right mandibular lateral incisor, in the primary dentition, as well as absence of both permanent mandibular lateral incisors. Fusion and gemination have not been previously referred to as typical dental features in KMS. The detection of unique dental findings, such as missing teeth and dental anomalies of form in the primary dentition by means of clinical and radiographic examinations, might consist of a helpful diagnosis parameter in identifying children who may have milder forms of Kabuki syndrome.

PMID: 17262134 [PubMed - indexed for MEDLINE]

Homozygous mutations in fibroblast growth factor 3 are associated with a new form of syndromic deafness characterized by inner ear agenesis, microtia, and microdontia.

Am J Hum Genet. 2007 Feb;80(2):338-44

Authors: Tekin M, Hi&#x15F;mi BO, Fitoz S, Ozdağ H, Cengiz FB, Sirmaci A, Aslan I, Inceoğlu B, Yüksel-Konuk EB, Yilmaz ST, Yasun O, Akar N

We identified nine individuals from three unrelated Turkish families with a unique autosomal recessive syndrome characterized by type I microtia, microdontia, and profound congenital deafness associated with a complete absence of inner ear structures (Michel aplasia). We later demonstrated three different homozygous mutations (p.S156P, p.R104X, and p.V206SfsX117) in the fibroblast growth factor 3 (FGF3) gene in affected members of these families, cosegregating with the autosomal recessive transmission as a completely penetrant phenotype. These findings demonstrate the involvement of FGF3 mutations in a human malformation syndrome for the first time and contribute to our understanding of the role this gene plays in embryonic development. Of particular interest is that the development of the inner ear is completely disturbed at a very early stage--or the otic vesicle is not induced at all--in all of the affected individuals who carried two mutant FGF3 alleles.

PMID: 17236138 [PubMed - indexed for MEDLINE]

[Prevalence of enamel defects and the relationship to dental caries in deciduous and permanent dentition in Indaiatuba, São Paulo, Brazil]

Cad Saude Publica. 2007 Feb;23(2):435-44

Authors: Hoffmann RH, de Sousa Mda L, Cypriano S

The aim of this study was to determine the prevalence of hypoplasia, demarcated opacity and dental fluorosis among schoolchildren with deciduous and permanent dentition. The association between enamel defects and dental caries was also verified. The sample consisted of 624 schoolchildren aged 5 and 309 aged 12. The dmft and DMFT indexes were used to assess dental caries prevalence, DDE to assess enamel defects, and Dean to assess fluorosis. Chi-squared test was used to test significance (p < 0.05) and odds ratio to analyze prevalence of dental caries and enamel defects. A positive association between dental caries and enamel defects (hypoplasia, demarcated opacity and dental fluorosis) was observed for schoolchildren aged 5. However, only hypoplasia and demarcated opacity were associated with caries experience in permanent dentition. The results of this study indicated that children had increased odds of dental caries when enamel defect was present, both in deciduous and permanent dentition; further studies are needed to give evidence to this association.

PMID: 17221093 [PubMed - indexed for MEDLINE]

Analyses of a novel L130F missense mutation in FOXC1.

Arch Ophthalmol. 2007 Jan;125(1):128-35

Authors: Ito YA, Footz TK, Murphy TC, Courtens W, Walter MA

OBJECTIVE: To understand how the novel L130F mutation, found in 2 patients with Axenfeld-Rieger syndrome, disrupts function of the forkhead box C1 protein (FOXC1). METHODS: Sequencing DNA from patients with Axenfeld-Rieger syndrome identified a novel missense mutation that results in an L130F substitution in the FOXC1 gene. Site-directed mutagenesis was used to introduce the L130F mutation into the FOXC1 complementary DNA. The level of L130F protein expression was determined by means of immunoblotting. We determined the mutant protein's ability to localize to the nucleus, bind DNA, and transactivate a reporter construct. RESULTS: The FOXC1 L130F mutant protein is expressed at levels similar to those of wild-type FOXC1. The L130F protein, however, migrated at an apparent reduced molecular weight compared with the wild-type protein, suggesting that the mutant and wild-type proteins may be differentially phosphorylated. The L130F protein also had a significantly impaired capacity to localize to the nucleus, bind DNA, and transactivate reporter genes. CONCLUSIONS: The disease-causing L130F mutation further demonstrates that helix 3 of the forkhead domain is important for the FOXC1 protein to properly localize to the nucleus, bind DNA, and activate gene expression. CLINICAL RELEVANCE: The inability of FOXC1 to function owing to the L130F mutation provides further insight into how disruptions in the FOXC1 gene lead to human Axenfeld-Rieger syndrome.

PMID: 17210863 [PubMed - indexed for MEDLINE]

Identification of four new PITX2 gene mutations in patients with Axenfeld-Rieger syndrome.

Mol Vis. 2006;12:1448-60

Authors: Vieira V, David G, Roche O, de la Houssaye G, Boutboul S, Arbogast L, Kobetz A, Orssaud C, Camand O, Schorderet DF, Munier F, Rossi A, Delezoide AL, Marsac C, Ricquier D, Dufier JL, Menasche M, Abitbol M

PURPOSE: Axenfeld Rieger syndrome (ARS) is an autosomal dominant inherited disorder affecting development of the ocular anterior chamber, abdomen, teeth and facial structures. The PITX2 gene is a major gene encoding a major transcription factor associated with ARS. METHODS: ARS patients were collected from six unrelated families. Patients and their families were ophthalmologically phenotyped and their blood was collected for DNA extraction. We screened the coding region of human PITX2 gene by direct sequencing. The consequences of the mutations described were investigated by generating crystallographic representations of the amino acid changes. In order to better understand the occurrence of glaucoma in ARS patients, we studied the PITX2 gene expression in human embryonic and fetal ocular tissue sections. RESULTS: We identified four novel PITX2 genetic alterations in four unrelated families with ARS. These mutations included two nonsense mutations (E55X and Y121X), an eight nucleotides insertion (1251 ins CGACTCCT) and a substitution (F58L), in familial and sporadic cases of ARS. We also showed for the first time that PITX2 is expressed at early stages of the human embryonic and fetal periocular mesenchyme, as well as at later stages of human development in the fetal ciliary body, ciliary processes, irido corneal angle and corneal endothelium. The human fetal eye PITX2 gene expression pattern reported here for the first time provides a strong basis for explaining the frequent occurrence of glaucoma in patients affected by PITX2 gene mutations. CONCLUSIONS: Two mutations identified affect the homeodomain (E55X and F58L). The E55X nonsense mutation is likely to alter dramatically the DNA-binding capabilities of the PITX2 homeodomain. Furthermore, there is a complete loss of the carboxy-terminal part of the PITX2 protein beyond the site of the mutation. The phenylalanine F58 is known to contribute to the hydrophobic network of the homeodomain. The crystallographic representations of the mutation F58L show that this mutation may change the conformation of the helical core. The F58L mutation is very likely to modify the homeodomain conformation and probably alters the DNA binding properties of PITX2. The other mutations (Y121X and the eight-nucleotide insertion (1251 ins CGA CTC CT) CGA CTC CT, at position 224 in PITX2A) result in partial loss of the C-terminal domain of PITX2. Pitx2 synergistically transactivates the prolactin promoter in the presence of the POU homeodomain protein Pit-1. Pitx2 activity is regulated by its own C-terminal tail. This region contains a highly conserved 14-amino-acid element involved in protein-protein interactions. The C-terminal 39-amino-acid tail represses DNA binding activity and is required for Pitx2 interactions with other transcription factors, for Pitx2-Pit-1 interaction and Pit-1synergism. Pit-1 interaction with the Pitx2 C terminus masks the inhibitory effect and promotes increased DNA binding activity. Thus, the partial or complete loss of the C terminus tail can lead to decreased or absent DNA binding activity and trigger severe ARS phenotypes. Our in situ hybridization results obtained on human embryonic and fetal ocular tissue sections constitute the first molecular histological data providing an explanation for the occurrence of precocious glaucoma in human patients affected by ARS caused by PITX2 mutations. Further structural and biochemical studies are needed for understanding the wide spectrum of clinical phenotypes caused by the increasing number of new PITX2 mutations found in ARS affected patients.

PMID: 17167399 [PubMed - indexed for MEDLINE]

Peripheral and central hypomyelination with hypogonadotropic hypogonadism and hypodontia.

Neurology. 2006 Dec 12;67(11):2066-9

Authors: Timmons M, Tsokos M, Asab MA, Seminara SB, Zirzow GC, Kaneski CR, Heiss JD, van der Knaap MS, Vanier MT, Schiffmann R, Wong K

We identified four unrelated patients (three female, one male) aged 20 to 30 years with hypomyelination, pituitary hypogonadotropic hypogonadism, and hypodontia. Electron microscopy and myelin protein immunohistochemistry of sural nerves showed granular debris-lined clefts, expanded abaxonal space, outpocketing with vacuolar disruption, and loss of normal myelin periodicity. Reduced galactocerebroside, sphingomyelin, and GM1-N-acetylglucosamine and increased esterified cholesterol were found. This is a clinically homogeneous progressive hypomyelinating disorder. The term 4H syndrome is suggested.

PMID: 17159124 [PubMed - indexed for MEDLINE]

The development of supernumerary teeth in the mandible in cases with a history of supernumeraries in the pre-maxillary region.

J Orthod. 2006 Dec;33(4):250-5

Authors: Hall A, Onn A

This article presents four cases in which delayed formation and late eruption of supernumerary teeth in the mandible occurred in patients with a history of supernumerary formation in the premaxilla region. In all cases, the premaxillary supernumeraries prevented eruption of the associated permanent incisor(s).

PMID: 17142331 [PubMed - indexed for MEDLINE]

Kabuki syndrome: a case report.

J Orthod. 2006 Dec;33(4):242-5

Authors: Lung ZH, Rennie A

This article reports the case of an 8-year-old female with Kabuki syndrome and the oral/dental implications of this syndrome, namely hypodontia with interdental spacing, abnormal tooth morphology, malocclusion and a defect in the anterior midline of the palate. The oral findings will aid the clinician in diagnosing this syndrome, which was once thought to be seen exclusively in the Japanese population.

PMID: 17142329 [PubMed - indexed for MEDLINE]

Identification of the first intragenic deletion of the PITX2 gene causing an Axenfeld-Rieger Syndrome: case report.

BMC Med Genet. 2006;7:82

Authors: de la Houssaye G, Bieche I, Roche O, Vieira V, Laurendeau I, Arbogast L, Zeghidi H, Rapp P, Halimi P, Vidaud M, Dufier JL, Menasche M, Abitbol M

BACKGROUND: Axenfeld-Rieger syndrome (ARS) is characterized by bilateral congenital abnormalities of the anterior segment of the eye associated with abnormalities of the teeth, midface, and umbilicus. Most cases of ARS are caused by mutations in the genes encoding PITX2 or FOXC1. Here we describe a family affected by a severe form of ARS. CASE PRESENTATION: Two members of this family (father and daughter) presented with typical ARS and developed severe glaucoma. The ocular phenotype was much more severe in the daughter than in the father. Magnetic resonance imaging (MRI) detected an aggressive form of meningioma in the father. There was no mutation in the PITX2 gene, determined by exon screening. We identified an intragenic deletion by quantitative genomic PCR analysis and characterized this deletion in detail. CONCLUSION: Our findings implicate the first intragenic deletion of the PITX2 gene in the pathogenesis of a severe form of ARS in an affected family. This study stresses the importance of a systematic search for intragenic deletions in families affected by ARS and in sporadic cases for which no mutations in the exons or introns of PITX2 have been found. The molecular genetics of some ARS pedigrees should be re-examined with enzymes that can amplify medium and large genomic fragments.

PMID: 17134502 [PubMed - indexed for MEDLINE]

Dilacerated unerupted central incisor: A case report.

J Indian Soc Pedod Prev Dent. 2006 Sep;24(3):152-4

Authors: Agnihotri A, Marwah N, Dutta S

Dilaceration of permanent successors is one of the most common complications of trauma to the deciduous teeth. It is advisable to keep these patients under observation post-trauma and to consult an orthodontist at an early stage to prevent unfavorable sequelae. Presented here is a typical case of dilaceration.

PMID: 17065784 [PubMed - indexed for MEDLINE]

Increased Young's modulus and hardness of Col1a2oim dentin.

J Dent Res. 2006 Nov;85(11):1032-6

Authors: Lopez Franco GE, Huang A, Pleshko Camacho N, Stone DS, Blank RD

Mice harboring the Col1a2(oim) mutation (oim) express dentinogenesis imperfecta. To determine the effect of Col1a2 genotype on tissue mechanical properties, we compared Young's modulus and hardness of dentin in the 3 Col1a2 genotypes. Upper incisors were tested by nanoindentation. Genotype had a significant effect on Young's modulus, but there was not a simple mutant allele dosage relationship. The effect of genotype on hardness did not reach significance. Hardness and Young's modulus were greater near the dento-enamel junction than near the pulp chamber. Greater hardness and Young's modulus values near the dento-enamel junction reflected continued mineralization of the dentin following its initial synthesis. Analysis showed the mechanical data to be consistent with Fourier transform infrared and backscattered electron microscopy studies that revealed increased mineralization in oim bone. Analysis of the data suggests that clinical fragility of teeth in oim mice is not due to deficiencies of hardness or Young's modulus, but may be due to defects in post-yield behavior or resistance to fatigue damage.

PMID: 17062745 [PubMed - indexed for MEDLINE]

The clinical features and aetiological basis of primary eruption failure.

Eur J Orthod. 2006 Dec;28(6):535-40

Authors: Ahmad S, Bister D, Cobourne MT

Primary failure of eruption (PFE) is a poorly understood condition associated with tooth eruption failure. This investigation systematically reviews the literature, evaluates clinical features and associations with PFE, and describes five further cases. Publications were selected and identified as describing PFE when there was no identifiable aetiological factor contributing to eruption failure and no evidence of successful orthodontic extrusion of the affected tooth or teeth. A data abstraction form recorded the following additional information; subject age, gender, general health status, and teeth present. Eighteen publications were sourced that detailed at least one case of PFE in a manner conforming to the selection criteria; these papers included a total of 35 individual cases, to which five previously unreported subjects were added. Within the whole sample of 40 cases, a total of 24 (60 per cent) were females and 16 (40 per cent) males. First and second molar teeth were most commonly affected; incisors, canines, and premolars were also involved, but with a reduced individual frequency. There was no significant difference in incidence between the maxilla and mandible, or between left and right sides. A family history of eruption failure was found in almost 50 per cent of the sample, with eruption failure or ankylosis affecting at least one primary tooth, also a common finding. Within the 40 cases, hypodontia was present at levels higher than population norms. PFE appears to be a condition that predominantly affects the molar dentition. The increased frequency of hypodontia in affected individuals and common findings of a family history regarding tooth eruption problems suggests a significant genetic component to the aetiology of this rare condition.

PMID: 17041084 [PubMed - indexed for MEDLINE]

Cleidocranial dysplasia: importance of radiographic images in diagnosis of the condition.

J Oral Sci. 2006 Sep;48(3):161-6

Authors: Tanaka JL, Ono E, Filho EM, Castilho JC, Moraes LC, Moraes ME

Cleidocranial dysplasia (CCD) is a rare syndrome usually caused by an autosomal dominant gene, although 40% of cases of CCD appear spontaneously with no apparent genetic cause. This condition is characterized by several cranial malformations and underdevelopment, absence of the clavicles, and multiple supernumerary and impacted permanent teeth. The diagnosis of this condition is usually based on the presence of the main features (supernumerary teeth, partial or total absence of one or both the clavicles, and bony malformations) and on clinical and familial evidence. The bony and dental features of CCD may be visualized on radiographic images of the face and skull. Here, we present a familial case of CCD and discuss the importance of dental radiographs in diagnosis of the condition.

PMID: 17023750 [PubMed - indexed for MEDLINE]

The Prx1 homeobox gene is critical for molar tooth morphogenesis.

J Dent Res. 2006 Oct;85(10):888-93

Authors: Mitchell JM, Hicklin DM, Doughty PM, Hicklin JH, Dickert JW, Tolbert SM, Peterkova R, Kern MJ

The paired-related homeobox genes, Prx1 and Prx2, encode transcription factors critical for orofacial development. Prx1(-/-)/Prx2(-/-) neonates have mandibular hypoplasia and malformed mandibular incisors. Although the mandibular incisor phenotype has been briefly described (ten Berge et al., 1998, 2001; Lu et al., 1999), very little is known about the role of Prx proteins during tooth morphogenesis. Since the posterior mandibular region was relatively normal, we examined molar tooth development in Prx1(-/-)/Prx2(-/-) embryos to determine whether the tooth malformation is primary to the loss of Prx protein or secondary to defects in surrounding tissues. Three-dimensional (3D) morphological reconstructions demonstrated that Prx1(-/-)/Prx2(-/-) embryos had molar malformations, including cuspal changes and ectopic epithelial projections. Although we demonstrate that Prx1 protein is expressed only mesenchymally, 3D reconstructions showed important morphological defects in epithelial tissues at the cap and bell stages. Analysis of these data suggests that the Prx homeoproteins are critical for mesenchymal-epithelial signaling during tooth morphogenesis.

PMID: 16998126 [PubMed - indexed for MEDLINE]

Bilaterally impacted maxillary central incisors: surgical exposure and orthodontic treatment: a case report.

J Contemp Dent Pract. 2006 Sep 1;7(4):98-105

Authors: Bayram M, Ozer M, Sener I

Maxillary central incisor impactions occur infrequently. Their origins include various local causes, such as odontoma, supernumerary teeth, and space loss. Supernumerary and ectopically impacted teeth are asymptomatic and found during routine clinical or radiological examinations. The surgical exposure and orthodontic traction of bilaterally impacted central incisors after removal of impacted supernumerary teeth is presented in this report.

PMID: 16957796 [PubMed - indexed for MEDLINE]

A sella turcica bridge in subjects with dental anomalies.

Eur J Orthod. 2006 Dec;28(6):580-5

Authors: Leonardi R, Barbato E, Vichi M, Caltabiano M

Calcification of the interclinoid ligament (ICL) of the sella turcica, or sella turcica bridging, has been associated with severe craniofacial deviations. Despite no comprehensive study on the sella turcica bridge, a relationship with tooth and eruption disturbances has been reported. In order to investigate whether congenital absence of the second mandibular premolar, or the presence of a palatally displaced canine (PDC), is associated with sella bridging, a retrospective study was performed. Lateral cephalometric radiographs from 20 males and 14 females, aged between 8 and 16 years, with a PDC and second mandibular premolar aplasia were reviewed and compared with a control group. A standardized scoring scale was established to quantify the extent of a sella turcica bridge from each radiograph (no calcification, partially calcified, and completely calcified). The prevalence of complete calcification of the ICL in adolescents with dental anomalies was equal to 17.6 per cent, while an incidence 9.9 per cent was found in the control group. A partially calcified sella turcica was observed in 58.8 per cent of adolescents with dental anomalies compared with 33.7 per cent in the control group. The association between the degree of calcification of the ICL and the presence of dental anomalies in the studied adolescents was statistically significant according to chi-square statistics (P = 0.004). This was confirmed by Fisher's exact test (P = 0.003). According to these findings, the prevalence of a sella turcica bridge in adolescents with dental anomalies is increased, while age and gender do not greatly influence ossification of the ICL. The very early appearance during development of a sella turcica bridge should alert clinicians to possible tooth anomalies in life later.

PMID: 16954179 [PubMed - indexed for MEDLINE]

Multidisciplinary treatment of mandibular prognathism with multiple congenitally missing teeth.

Bull Tokyo Dent Coll. 2006 Feb;47(1):25-31

Authors: Nishimura R, Nojima K, Nishii Y, Hanai J, Arataki T, Uchiyama T, Yamaguchi H

Surgical orthodontic treatment and dental implant therapy were performed on a man (aged 18 years 8 months) with mandibular prognathism and seven congenitally missing teeth: upper canines, first and second premolars and lower right second premolar. After 17 months of preoperative orthodontic treatment at age 20 years 1 month, sagittal split ramus osteotomy was performed using the remaining upper deciduous teeth as an anchor for intermaxillary fixation. In postoperative orthodontic treatment, the remaining deciduous teeth were extracted, and fixture installation was performed. The entire therapy required 4 years to complete (age 22 years 8 months). After completion of orthodontic treatment, superstructures were put in place. This patient had many dental problems, so multidisciplinary care was performed in conjunction with other departments to improve oral function and facial esthetics.

PMID: 16924156 [PubMed - indexed for MEDLINE]

Two cases with supernumerary teeth in lower incisor region.

Bull Tokyo Dent Coll. 2006 Feb;47(1):19-23

Authors: Yokose T, Sakamoto T, Sueishi K, Yatabe K, Tsujino K, Kubo S, Yakushiji M, Yamaguchi H

Abnormalities in number of teeth are occasionally noted in clinical cases. Many theories have been proposed as regards the causes of the occurrence of supernumerary teeth, including atavism theory, mechanical tooth germ separation theory, tissue induction theory, and dental laminar morphological disturbance theory. However, none of these theories alone offers a sufficient explanation for this phenomenon. The incidence of supernumerary permanent teeth is approximately 1-3%. These are the maxillary anterior teeth, the maxillary molars, and the maxillo-mandibular premolars in terms of descending order of site of occurrence. On the other hand, incidence in the mandibular anterior tooth area, of which there have been few detailed reports, is about 0.01%, a markedly low value. In this paper, we report two rare cases of supernumerary teeth in the mandibular incisor area. We discuss their etiology and orthodontic treatment, and detail a differential diagnosis between the normal and supernumerary teeth. We found that it was difficult to establish a clear etiology and differentiation between the normal and supernumerary teeth.

PMID: 16924155 [PubMed - indexed for MEDLINE]

Functional characterization of a GJA1 frameshift mutation causing oculodentodigital dysplasia and palmoplantar keratoderma.

J Biol Chem. 2006 Oct 20;281(42):31801-11

Authors: Gong XQ, Shao Q, Lounsbury CS, Bai D, Laird DW

A frameshift mutation generated from a dinucleotide deletion (780-781del) in the GJA1 gene encoding Cx43 results in a frameshift yielding 46 aberrant amino acids after residue 259 and a shortened protein of 305 residues compared with the 382 in wild-type Cx43. This frameshift mutant (fs260) causes oculodentodigital dysplasia (ODDD) that includes the added condition of palmoplantar keratoderma. When expressed in a variety of cell lines, the fs260 mutant was typically localized to the endoplasmic reticulum and other intracellular compartments. The fs260 mutant, but not the G138R ODDD-linked Cx43 mutant or a Cx43 mutant truncated at residue 259 (T259), reduced the number of apparent gap junction plaques formed from endogenous Cx43 in normal rat kidney cells or keratinocytes. Interestingly, mutation of a putative FF endoplasmic reticulum retention motif encoded within the 46 aberrant amino acid domain failed to restore efficient assembly of the fs260 mutant into gap junctions. Dual whole cell patch-clamp recording revealed that fs260-expressing N2A cells exerted severely reduced electrical coupling in comparison to wild-type Cx43 or the T259 mutant, whereas single patch capacitance recordings showed that fs260 could also dominantly inhibit the function of wild-type Cx43. Co-expression studies further revealed that the dominant negative effect of fs260 on wild-type Cx43 was dose-dependent, and at a predicted 1:1 expression ratio the fs260 mutant reduced wild-type Cx43-mediated gap junctional conductance by over 60%. These results suggest that the 46 aberrant amino acid residues associated with the frameshift mutant are, at least in part, responsible for the manifestation of palmoplantar keratoderma symptoms.

PMID: 16891658 [PubMed - indexed for MEDLINE]

The molecular etiologies and associated phenotypes of amelogenesis imperfecta.

Am J Med Genet A. 2006 Dec 1;140(23):2547-55

Authors: Wright JT

The amelogenesis imperfectas (AIs) are a clinically and genetically diverse group of conditions that are caused by mutations in a variety of genes that are critical for normal enamel formation. To date, mutations have been identified in four genes (AMELX, ENAM, KLK4, MMP20) known to be involved in enamel formation. Additional yet to be identified genes also are implicated in the etiology of AI based on linkage studies. The diverse and often unique phenotypes resulting from the different allelic and non-allelic mutations in these genes provide an opportunity to better understand the role of these genes and their related proteins in enamel formation. Understanding the AI phenotypes also provides an aid to clinicians in directing molecular studies aimed at delineating the genetic basis underlying these diverse clinical conditions. Our current knowledge of the known mutations and associated phenotypes of the different AI subtypes are reviewed.

PMID: 16838342 [PubMed - indexed for MEDLINE]

Surgical and orthodontic treatment of an impacted permanent central incisor: a case report.

J Indian Soc Pedod Prev Dent. 2006 Jun;24(2):100-3

Authors: Thosar NR, Vibhute P

Although impaction of a permanent tooth is rarely diagnosed during the mixed dentition period, an impacted central incisor is usually diagnosed accurately when there is delay in the eruption of tooth. In this article, the impacted incisor was moved into it's proper position with surgical exposure and orthodontic traction, after which it showed good stability.

PMID: 16823236 [PubMed - indexed for MEDLINE]

Telescopic crowns in adult case with lip and palate cleft. Update on the etiology and management.

Med Oral Patol Oral Cir Bucal. 2006 Jul;11(4):E358-62

Authors: Ma&#xF1;es Ferrer JF, Martínez González A, Oteiza Galdón B, Bouazza Juanes K, Benet Iranzo F, Candel Tomás A

Lip and palatal clefts are among the most important congenital craniofacial malformations to be taken into account in general dental practice, due to their high incidence and important repercussions upon the oral cavity. The underlying causes are genetic and fundamentally environmental, and the disorders manifest as early as in the embryonic period. Males are predominantly affected, with a 7:3 ratio versus females. Our patient, a 20-year-old male, presented the most common association, i.e., total unilateral hare lip with palatal cleft. A description is provided of the treatment for his dental problem, together with an update on the etiology and management of adults with malformations of this kind.

PMID: 16816823 [PubMed - indexed for MEDLINE]

Retrospective study of 145 supernumerary teeth.

Med Oral Patol Oral Cir Bucal. 2006 Jul;11(4):E339-44

Authors: Fernández Montenegro P, Valmaseda Castellón E, Berini Aytés L, Gay Escoda C

OBJECTIVE: The goal of the present retrospective study is to describe the distribution of the supernumerary teeth in a population of patients that have been attended at the Public Clinic of the Department of Oral Surgery. BACKGROUND: Supernumerary teeth and multiple hyperdontia are usually associated with different syndromes, such as Gardner syndrome, or with facial fissures; however, they can appear in patients without any pathology. Their prevalence oscillates to 0.5-3.8% in patients with permanent teeth and to 0.35-0.6% in patients with primary teeth. PATIENTS AND METHODS: A total of 36,057 clinical histories of patients that were admitted at the clinic between September of 1991 and March of 2003 were revised. The following data were extrapolated: age, sex, number of extracted supernumerary teeth, localization, morphology and type of supernumerary teeth. Consequently, 102 patients were included into the present study. RESULTS: Of the 147 supernumerary teeth identified in the oral cavities of patients 145 were extracted. The most frequent supernumerary teeth identified were mesiodens (46.9%), followed by premolars (24.1%) and fourth molars or distal molars (18%). As for location, 74.5% of the supernumerary teeth were found in the superior maxillary bone and 46.9% of the supernumerary teeth were present in the palatine/lingual area. Heteromorphology was found in two thirds of the supernumerary teeth, with conical shape being the most frequent. Finally, 29.7% of the supernumerary teeth had occlusion with permanent teeth, and mesiodens were the predominating type of supernumerary teeth that showed this feature. CONCLUSIONS: Mesiodens very frequently cause retention of permanent incisors, which erupt spontaneously after the extraction of supernumerary teeth, if there is sufficient space in the dental arch and if they conserve the eruptive force. Generally, supernumerary premolars are eumorphic and are casually discovered during radiological exam, if not producing any symptomology.

PMID: 16816819 [PubMed - indexed for MEDLINE]

A nonsense mutation in the first transmembrane domain of connexin 43 underlies autosomal recessive oculodentodigital syndrome.

J Med Genet. 2006 Jul;43(7):e37

Authors: Richardson RJ, Joss S, Tomkin S, Ahmed M, Sheridan E, Dixon MJ

BACKGROUND: Oculodentodigital syndrome (ODD) is a pleiotropic congenital disorder characterised by abnormalities of the face, eyes, dentition, and limbs. ODD, which is inherited as an autosomal dominant trait, results from missense mutations in the gap junction protein connexin 43. OBJECTIVE: To analyse a family with a history of ODD which is inherited in an autosomal recessive manner RESULTS: ODD in this family resulted from the homozygous mutation R33X in the first transmembrane domain of connexin 43. CONCLUSIONS: The findings provide clear genetic evidence that ODD can be inherited in an autosomal recessive manner and that a dominant negative mechanism underlies autosomal dominant ODD.

PMID: 16816024 [PubMed - indexed for MEDLINE]

Gene discovery for dental anomalies: a primer for the dental professional.

J Am Dent Assoc. 2006 Jun;137(6):743-52

Authors: Pemberton TJ, Gee J, Patel PI

BACKGROUND: Thousands of inherited human disorders have been catalogued to date, but the underlying genetic causes of less than 20 percent of those disorders have been discovered. TYPE OF STUDIES REVIEWED: The completion of the Human Genome Project (HGP) has made available the DNA sequence of all 24 human chromosomes, thereby allowing the localization of all human genes and, ultimately, determination of their function. Disease gene discovery is being expedited greatly by the data from the HGP, thereby paving the way for determination of the genetic etiology of most of these disorders. RESULTS: While most dental anomalies can severely affect patients' quality of life, they are not fatal, which makes multigenerational families with these disorders available for study. These families are invaluable for genetic studies. Despite this fact, the discovery of genes underlying non-syndromic dental anomalies has lagged behind that for anomalies affecting other organ systems. The authors present an overview of the methodologies of disease gene identification using hypodontia, which is one of the most common anomalies of the dentition, to illustrate the application of these principles. CLINICAL IMPLICATIONS: An understanding of the advances in human genetics should inspire the practicing dental professional to ascertain whether a dental anomaly is inherited and, if so, work with a human geneticist to identify its underlying genetic mechanism.

PMID: 16803803 [PubMed - indexed for MEDLINE]

Is mild dental invagination a risk factor for apical root resorption in orthodontic patients?

Eur J Orthod. 2006 Aug;28(4):307-12

Authors: Mavragani M, Apisariyakul J, Brudvik P, Selvig KA

The purpose of this retrospective study was to assess if dental invagination is a risk factor for root resorption during orthodontic treatment. The sample consisted of 91 patients (32 males, 59 females) with a mean age of 13.1 years (range 9.3-32.1 years) with complete orthodontic records, including periapical radiographs of the maxillary incisors before and after treatment. Forty-nine patients had at least one maxillary incisor invaginated, whilst the remaining 42 patients were free of dental invaginations. Variables recorded for each patient included gender, age, Angle classification, extraction or non-extraction therapy, ANB angle, overjet, overbite, trauma, habits, agenesis, tooth exfoliation, treatment duration, Class II elastics, body-build, general factors, impacted canines, and root form deviation. Crown and root length of the maxillary incisors were measured on pre- and post-treatment long cone periapical radiographs corrected for image distortion. The percentage of root shortening and root length loss in millimetres was then calculated. Most of the invaginated teeth were minor type 1. Statistical analysis revealed no significant difference in the severity of apical root resorption between invaginated and non-invaginated incisors in patients without dental invaginations, nor was the extent of dental invagination related to the severity of apical root resorption. However, invaginated teeth had malformed roots more often than non-invaginated teeth. Dental invagination, and particularly type 1, cannot be considered a risk factor for apical root resorption during orthodontic tooth movement.

PMID: 16763089 [PubMed - indexed for MEDLINE]

Ectopia or concomitant hypohyperdontia? A case report.

J Orthod. 2006 Jun;33(2):71-7

Authors: Bateman G, Mossey PA

This report describes the unusual appearance seen on a panoramic radiograph of an orthodontic patient which the authors argue may represent ectopia or concomitant hypohyperdontia of the mandibular premolar teeth. A literature review describes the frequency of such anomalies in this area from previous studies. The presenting features of the patient and the differential diagnoses are explored. Treatment planning is discussed and treatment carried out in this particular case is detailed. The unusual symmetrical bilateral anomalies in this patient may point to a genetic determinant of tooth germ position and/or movement.

PMID: 16751428 [PubMed - indexed for MEDLINE]

Delineation of the ADULT syndrome phenotype due to arginine 298 mutations of the p63 gene.

Eur J Hum Genet. 2006 Aug;14(8):904-10

Authors: Rinne T, Spadoni E, Kjaer KW, Danesino C, Larizza D, Kock M, Huoponen K, Savontaus ML, Aaltonen M, Duijf P, Brunner HG, Penttinen M, van Bokhoven H

The ADULT syndrome (Acro-Dermato-Ungual-Lacrimal-Tooth, OMIM 103285) is a rare ectodermal dysplasia associated with limb malformations and caused by heterozygous mutations in p63. ADULT syndrome has clinical overlap with other p63 mutation syndromes, such as EEC (OMIM 604292), LMS (OMIM 603543), AEC (106260), RHS (129400) and SHFM4 (605289). ADULT syndrome characteristics are ectrodactyly, ectodermal dysplasia, mammary gland hypoplasia and normal lip and palate. The latter findings allow differentiation from EEC syndrome. LMS differs by milder ectodermal involvement. Here, we report three new unrelated ADULT syndrome families, all with mutations of arginine 298. On basis of 16 patients in five families with R298 mutation, we delineate the ADULT syndrome phenotype. In addition, we have documented a gain-of-function effect on the dNp63gamma isoform caused by this mutation. We discuss the possible relevance of oral squamous cell carcinoma in one patient, who carries this p63 germline mutation.

PMID: 16724007 [PubMed - indexed for MEDLINE]

MSX1 and orofacial clefting with and without tooth agenesis.

J Dent Res. 2006 Jun;85(6):542-6

Authors: Modesto A, Moreno LM, Krahn K, King S, Lidral AC

MSX1 has been considered a strong candidate for orofacial clefting, based on mouse expression studies and knockout models, as well as association and linkage studies in humans. MSX1 mutations are also causal for hereditary tooth agenesis. We tested the hypothesis that individuals with orofacial clefting with or without tooth agenesis have MSX1 coding mutations by screening 33 individuals with cleft lip with or without cleft palate (CL/P) and 19 individuals with both orofacial clefting and tooth agenesis. Although no MSX1 coding mutations were identified, the known 101C > G variant occurred more often in subjects with both CL/P and tooth agenesis (p = 0.0008), while the *6C-T variant was found more often in CL/P subjects (p = 0.001). Coding mutations in MSX1 are not the cause of orofacial clefting with or without tooth agenesis in this study population. However, the significant association of MSX1 with both phenotypes implies that MSX1 regulatory elements may be mutated.

PMID: 16723652 [PubMed - indexed for MEDLINE]

Dental treatment strategies in a 40-year-old patient with cleidocranial dysplasia.

J Appl Genet. 2006;47(2):199-201

Authors: Olszewska A

Oral anomalies and dental treatment in a patient with cleidocranial dysplasia (referred to the dental clinic at the age of 40 years) are presented. Five supernumerary teeth were found in the patient: three in the maxilla in the area of molars and two in the mandibula in the area of premolars. Therapy included surgical exposure of impacted teeth in combination with removal of supernumerary teeth.

PMID: 16682765 [PubMed - indexed for MEDLINE]