Dental Malformations Research Articles

Tongue and Posture

F. MARQUET. Before beginning I should like to thank you for agreeing to make a contribution to this issue devoted to posturology. In addition to tongue posture, a subject to which we’ll return later, what are the principal postural problems that should be considered in orthodontics? Maryvonne FOURNIER. The head hanging down in a forward position is one of the poor postures that are frequently encountered. It is associated with painful points in the occipital crest and sometimes prevents correction of breathing difficulties and problems with the tempero-mandibular joint. Mandibular deviations with which scoliosis, or a scoliatic tendency, are frequently associated with or without tendency to favor putting weight on one foot. Flat feet with disappearance of the inner arch of the foot, with weight placed purely on the posterior part of the foot in certain dental and skeletal Class III cases and exclusively on the anterior part of the foot in certain Class II dental and skeletal cases. F.M. You’re saying that poor weight distribution on the feet can cause dental or skeletal malformations? M.F. When too much weight is placed on the back f the foot, the child is always leaning backward, so much so that if we ask them to lean on the front part of the foot they might break their face and we need to place ourselves well in front of them to catch them if need be. In 50% of Class III cases we are going to find that in addition to this posterior weight distribution there is a recurvatum of the knees and a smoothing out of the lumbar, dorsal, and cervical curvatures. But, on the contrary, in Class II cases where patients place more weight on the front part of the foot there will be a flexum of the knee and an increase in the spinal curvatures. The patients whose thoracic cage tends to be caved in and under-developed usually have Class II Division 1 malocclsions and are mouth breathers. I cannot say that this type of poor development inevitably leads to dento-facial malformation. Some lateral mandibular deviations cause no postural problems whatever.

Dens invaginatus and treatment options based on a classification system: report of a type II invagination

To give an overview of treatment options for dens invaginatus based on a classification system. Dens invaginatus is a dental malformation which may give endodontic complications. Treatment may vary in relation to anatomy, and a classification system for dens invaginatus forms the basis for discussion. A clinical case, classified as a type II invagination (Oehlers' classification), is also presented. Clinical and radiographic examination revealed an invagination penetrating into the apical third of the root canal in tooth number 12. The tooth was immature with an open apex, apical pathosis and a labial fistula. To control the infection, ultrasonic removal of the invagination was necessary, as the invagination prevented complete cleaning and shaping of the root canal. After chemo-mechanical preparation and dressing with calcium hydroxide, an apical plug of MTA was placed, followed by restoration of the tooth with resin-bonded composite. Healing of the lesion with hard tissue formation was confirmed at follow-up. KEY LEARNING POINTS * Knowledge about classification and anatomical variations of teeth with dens invaginatus is important in endodontic decision making. * A classification system may be helpful when treatment options are considered. * Classification of dens invaginatus requires a thorough preoperative radiographic examination.

Mums, Dummies and ‘Dirty Dids’: The Dummy as a Symbolic Representation of Mothering?

The bio medical expert literature, although contested, associates the use of dummies, soothers or pacifiers, with illness, dental malformation, impaired speech and language, and working‐class mothering. This article suggests this negative perspective has filtered, via experts and the media, into public narratives of ‘good’ mothering. Interviews with 20 disadvantaged mothers demonstrate the complex negotiations undertaken to integrate dummy use into their personal ‘good‐mothering’ narratives. Representing their hitherto ignored voices in the dummy debate allows a consideration of the context of, and influences on, dummy use. The article argues that rather than a symbol of inadequate working‐class mothering, dummy use is a complex, highly negotiated, situated mothering practice.

Intragenic microdeletion of RUNX2 is a novel mechanism for cleidocranial dysplasia

Cleidocranial dysplasia (CCD; MIM 119600) is a rare autosomal dominant disorder characterized by facial, dental, and skeletal malformations. To date, rearrangement and mutations involving RUNX2, which encodes a transcription factor required for osteoblast differentiation on 6p21, has been the only known molecular etiology for CCD. However, only 70% patients were found to have point mutations, 13% large/contiguous deletion but the rest of 17% remains unknown. We ascertained a family consisted of eight affected individuals with CCD phenotypes. Direct sequencing analysis revealed no mutations in the RUNX2. Real time quantitative PCR were performed which revealed an exon 2 to exon 6 intragenic deletion in RUNX2. Our patients not only demonstrated a unique gene change as a novel mechanism for CCD, but also highlight the importance of considering "deletion" and "duplication" in suspected familial cases before extensive effort of gene hunting be carried.

Dentin Sialophophoprotein (DSPP) and Dentin.

The revolution in genetics disclosed the types of malformations that occur when expression of a particular gene is lost. In the case of tooth dentin, mutations in the two genes encoding type I collagen cause osteogenesis imperfecta, a bone condition that often includes dentin malformations. Besides collagen, there are a number of non-collagenous proteins in dentin. Among the genes encoding the dentin non-collagenous proteins, only mutations in DSPP (dentin sialophosphoprotein) cause inherited dental malformations. DSPP mutations cause dentinogenesis imperfecta types II and III, and dentin dysplasia type II. DSPP is the most abundant non-collagenous protein in dentin. DSPP protein is necessary for proper dentin formation, and understanding its structure and function should yield important insights into how dentin forms and biomineralization is controlled. DSPP is expressed and secreted by odontoblasts, the cells that make tooth dentin and that also maintain cell processes extending into the mineralized tissue. Following its secretion, DSPP is cleaved into smaller pieces by multiple extracellular proteases. For the last five years I have devoted myself to characterizing DSPP-derived proteins. DSPP is cleaved by proteases into three main parts : dentin sialoprotein (DSP), dentin glycoprotein (DGP), and dentin phosphoprotein (DPP). We have learned that DSP is a proteoglycan that forms covalent dimers, DGP is a phosphorylated glycoprotein, and DPP is a highly phosphorylated intrinsically disordered protein that shows extensive length polymorphisms due to the genetic heterogeneity of its coding region.

Abnormalities in tooth morphology, structure and dentition in two children with chromosome aberrations. Translocation trisomy 13 and trisomy 21

Dental malformations due to chromosomal trisomies are rarely described and need an intensive cooperation between pediatricians, orthodonticians and human geneticists to enable the collection of data and to extend the investigations on specific parameters of the teeth. Here we present tooth studies of two children with trisomies 13 (Pätau-syndrome) and 21 (Down-syndrome): the dentition, the tooth morphology and the structure as well as the composition were investigated over a period of six years. Both male patients showed a delayed and abnormal dentition. Morphologic and structural changes compared to the general population were also detectable; whereas, the composition of the teeth was unchanged in enamel, dentin, and the border between them. The abnormalities in all parameters investigated were more pronounced in the patient with Pätau-syndrome than in the child with Down-syndrome.

Sonic hedgehog expression during early tooth development in Suncus murinus

Tooth development is a highly organized process characterized by reciprocal interactions between epithelium and mesenchyme. However, the expression patterns and functions of molecules involved in mouse tooth development are unclear from the viewpoint of explaining human dental malformations and anomalies. Here, we show the expression of sonic hedgehog ( Shh), a potent initiator of morphogenesis, during the early stages of tooth development in Suncus murinus. Initially, symmetrical, elongated expression of suncus Shh ( sShh) was observed in the thin layer of dental epithelial cells along the mesial–distal axis of both jaws. As the dental epithelium continued to develop, sShh was strictly restricted to the predicted leading parts of the growing, invaginating epithelium corresponding to tooth primordia and enamel knots. We propose that some aspects of Shh function in tooth development are widely conserved in mammalian phylogeny.

Familial keratosis follicularis spinulosa decalvans associated with woolly hair

Keratosis follicularis spinulosa decalvans (KFSD) is a rare inherited disorder of keratinization clinically characterized by diffuse follicular hyperkeratosis, progressive scarring alopecia of scalp, eyebrows and eyelashes, corneal dystrophy and photophobia. Woolly hair is a hereditary condition, transmitted as an autosomal dominant or recessive trait, usually seen in Caucasians at birth or shortly after, in which there are curly, thick, often heavily pigmented hairs. We report two cases, a son and his mother, in whom KFSD occurred in association with woolly hair. In addition, various dental anomalies, including agenesis, inclusions and teeth malformations, were present in the child. Interestingly, both patients simultaneously developed an inflammatory tinea capitis caused by Microsporum canis. To our knowledge, the association of KFSD with woolly hair has not been described. The dental anomalies found in the child are intriguing, as they have never been reported previously in patients with KFSD. Finally, the concomitant onset of inflammatory tinea capitis in both patients may be explained by the enhanced susceptibility to fungal infection in keratinizing disorders.

Mutations in X-linked PORCN, a putative regulator of Wnt signaling, cause focal dermal hypoplasia

Focal dermal hypoplasia is an X-linked dominant disorder characterized by patchy hypoplastic skin and digital, ocular and dental malformations. We used array comparative genomic hybridization to identify a 219-kb deletion in Xp11.23 in two affected females. We sequenced genes in this region and found heterozygous and mosaic mutations in PORCN in other affected females and males, respectively. PORCN encodes the human homolog of Drosophila melanogaster porcupine, an endoplasmic reticulum protein involved in secretion of Wnt proteins.

Developmental biology and genetics of dental malformations

The synthesis of tooth development biology with human studies focusing on inherited conditions that specifically interfere with tooth development is improving our understanding of normal and pathological tooth formation. The type of inherited dental malformations observed in a given kindred relate to when, during odontogenesis, the defective gene is critically expressed. Information about the protein encoded by the defective gene and the resulting dental phenotype helps us understand the major processes underway at different stages during tooth development. Genes affecting early tooth development (PAX9, MSX1, and AXIN2) are associated with familial tooth agenesis or oligodontia. Genes expressed by odontoblasts (COL1A1, COL1A2, and DSPP), and ameloblasts (AMELX, ENAM, MMP20, and KLK4) during the crown formation stage, are associated with dentinogenesis imperfecta, dentin dysplasia, and amelogenesis imperfecta. Late genes expressed during root formation (ALPL and DLX3) are associated with cementum agenesis (hypophosphatasia) and taurodontism. Understanding the relationships between normal tooth development and the dental pathologies associated with inherited diseases improves our ability to diagnose and treat patients suffering the manifestations of inherited dental disorders.

L'étude des hypoplasies linéaires de l'émail et la caractérisation de l'élevage porcin au Moyen Âge sur les sites de Boves (Somme) et de Vincennes (Val-de-Marne)

Pathologies which may appear on the bones or teeth of an animal are related to its health and its living conditions. A dental malformation known as linear enamel hypoplasia (LEH) is caused by temporary insufficiencies in the build-up of the enamel as the crown develops. This anomaly is characterised by the appearance of lines or ridges on the surface of the crown. The study of these lines makes it possible to propose chronological models of periods of physiological stress occurring during the animal's development, and can often be related to a deterioration in diet. The first results obtained from the castle sites of Boves (eighth century - fourteenth century) and Vincennes (fourteenth century) suggest that variations in the number and aspect of the lines observed on the teeth of pigs may be related to environmental conditions and livestock farming practices current between the eighth and the fourteenth centuries. Thanks to the observation of LEH occurrence, comparisons may be established between different sites, or different phases of one particular site. The possibility of comparing several periods on the same site also provides an opportunity to research the incidents or conditions in the livestock raising process that may have determined these variations.

Short root anomaly associated with Rothmund-Thomson syndrome

A case of short root anomaly in a patient with Rothmund-Thomson syndrome is reported. The syndrome is a rare genodermatosis characterized by poikilodermatous rash starting in infancy, associated with juvenile cataracts, small stature, skeletal abnormalities, dental malformations, and predisposition to skin and bone cancers. In this case, abnormally short roots were detected during radiographic examination, affecting a complete permanent dentition including partially erupted third molars. The report contains a short review of the current literature on Rothmund-Thomson syndrome.

The endo‐perio lesion: a critical appraisal of the disease condition

Endodontic–periodontal lesions present challenges to the clinician as far as diagnosis and prognosis of the involved teeth are concerned. Etiologic factors such as bacteria, fungi, and viruses as well as various contributing factors such as trauma, root resorptions, perforations, and dental malformations play an important role in the development and progression of such lesions. Treatment and prognosis of endodontic–periodontal diseases vary and depend on the cause and the correct diagnosis of each specific condition. This article will appraise the interrelationship between endodontic and periodontal diseases and provide biological and clinical evidence of significance for diagnosis, prognosis, and decision‐making in the treatment of these conditions.

Lacrimoauriculodentodigital syndrome with cleft lip/palate and renal manifestations.

To describe the largest family reported with the lacrimoauriculodentodigital (LADD) syndrome. A family study of eight individuals with LADD syndrome. Pediatric Clinical Research Center at Oakland Children's Hospital. Eight individuals in a four-generation family. A diagnosis of LADD syndrome was determined by the presence of one or more of the characteristic lacrimal duct, auricular, dental, or digital malformations. Tear function and orofacial clefting were also considered in the final diagnosis of LADD syndrome. Affected family members had the characteristic features of LADD syndrome, including cup-shaped ears; lacrimal duct obstruction; and dental, forearm, and digit malformations. In addition to the cardinal features of LADD syndrome, the proband was born with cleft lip and palate. The mother and sister of the proband have hydronephrosis, a rare feature of the disorder. Family members also have features not previously described in LADD syndrome, including vesicoureteral reflux, recurrent urinary tract infections, camptodactyly, distal thumb symphalangism, and a bicornuate uterus. The findings suggest that the presence of vesicoureteral reflux and recurrent urinary tract infections should be evaluated in LADD syndrome patients and that the distinction of LADD syndrome from ectrodactyly-ectodermal dysplasia and clefting syndrome by the absence of clefting may need to be reconsidered.

Congenital mesenchymal chondrosarcoma of the orbit: Case report and review of the literature

Purpose To report the first case of congenital extraskeletal mesenchymal chondrosarcoma arising in the orbit. Design Interventional case report and review of the literature. Methods Ophthalmologic examination and computed tomography scan of the orbit were performed. Histologic and histochemical examination and immunohistochemistry of the biopsy specimen were evaluated. Main outcome measures Ocular and systemic disease control. Results A 5-month-old girl was seen with a papillomatous lesion in the right lower tarsal conjunctiva present from birth. Histologic examination demonstrated an admixture of undifferentiated mesenchymal cells and islands of mature hyaline cartilage, and immunohistochemistry studies revealing positivity for vimentin and S-100 were consistent with the diagnosis of mesenchymal chondrosarcoma. The patient was treated with combined chemotherapy (ifosfamide, epirubicin, and cisplatin), radiotherapy, and surgery (exenteration). She is alive with no evidence of disease after 4 years of follow-up. Facial asymmetry and dental malformations have developed as late effects. Further reconstructive surgery is planned for the malformations. Conclusions Extraskeletal mesenchymal chondrosarcoma in the orbit is extremely rare. This study reports the first case of congenital extraskeletal mesenchymal chondrosarcoma arising in the orbit (also the youngest patient) both in skeletal and extraskeletal sites. Multimodality treatment (surgery, chemotherapy, and radiotherapy) may lead to long-term survival.

Congenital universal hypertrichosis with deafness and dental anomalies inherited as an X-linked trait.

We report a large Mexican kindred with a variant form of congenital universal hypertrichosis that is inherited in an apparent X-linked recessive manner. In addition to the generalized hypertrichosis, the affected individuals have dental malformations and deafness. Males are more severely affected than females who exhibit only mild hypertrichosis, but not deafness or dental anomalies. Haplotype analysis in this pedigree revealed linkage to a 13-cM region on chromosome Xq24-q27.1 between markers GATA198A10 and DXS8106. Localization of the gene underlying this form of hypertrichosis is the initial step in identifying genes on the X chromosome that are involved in the control of hair growth and development.

Syndrome de Johanson-Blizzard : à propos d'un cas

The Johanson-Blizzard syndrome is a rare autosomal recessive syndrome. This syndrome includes congenital aplasia of the cutis, aplasia of the alae nasi, bilateral hearing loss, dental malformations and pancreatic insufficiency. Case report – We report a sporadic case male infant from nonconsanguineous parents. He presented aplasia of the cutis and high anorectal malformation, associated with exocrine pancreatic insufficiency. A colostomy was performed at birth and anorectal atresia was corrected surgically at two months. Exocrine pancreatic insufficiency required immediate enzyme supplementation.

Unilateral primary or secondary retention of permanent teeth, and dental malformations.

The purpose of the present investigation was to describe the dentition in subjects with local primary or secondary unilateral retention of two or more permanent teeth, and to elucidate the aetiology by comparing the regions of retention with the innervation pattern of the jaws. The material comprised radiographic dental orthopantomograms (OTP) from 12 patients with an age range of 6-18 years (six females and six males). The locations of retention and the dental morphology in the affected regions were analysed. Comparison with contralateral teeth was undertaken and the innervation pattern of the affected field was considered. Varying degrees of dental root malformation were found to be associated with primary and secondary retention. More pronounced root malformations were observed in subjects with several affected teeth. A connection between unilateral retained permanent teeth and temporary or permanent disruption of the nerve supply to the affected region is suggested.

Dental injuries due to African traditional therapies for diarrhea.

The number of immigrants and refugees from Asia and Africa to developed countries has increased in the past 20 years. Through caring for these patients, western physicians have become increasingly aware of traditional healing practices such as coining, cupping, and herbal therapies.1 Most physicians know little about traditional healing practices involving the mouth. We present 3 cases of dental malformations from care provided by traditional healers in East Africa (figures​(figures11,​,2,2, and​and33). Figure 1 On a routine physical examination, this 6-year-old Somali boy, a recent immigrant to the United States, was noted to be missing both primary lowercuspids. Figure 2 A 7-year-old Somali boy (brother of boy infigure 1) was also noted on a routine physical examination to have enamel defects located centrally on the buccal surface of both lower cuspids. The right cuspid was broken off above the defect. Figure 3 A 16-year-old Somali boy, who had been in the United States for several years, was noted by his primary care dentist to be missing both permanent lower incisors.

Neuro-osteology.

Neuro-osteology stresses the biological connection during development between nerve and hard tissues. It is a perspective that has developed since associations were first described between pre-natal peripheral nerve tissue and initial osseous bone formation in the craniofacial skeleton (Kjaer, 1990a). In this review, the normal connection between the central nervous system and the axial skeleton and between the peripheral nervous system and jaw formation are first discussed. The early central nervous system (the neural tube) and the axial skeleton from the lumbosacral region to the sella turcica forms a unit, since both types of tissue are developmentally dependent upon the notochord. In different neurological disorders, the axial skeleton, including the pituitary gland, is malformed in different ways along the original course of the notochord. Anterior to the pituitary gland/sella turcica region, the craniofacial skeleton develops from prechordal cartilage, invading mesoderm and neural crest cells. Also, abnormal development in the craniofacial region, such as tooth agenesis, is analyzed neuro-osteologically. Results from pre-natal investigations provide information on the post-natal diagnosis of children with congenital developmental disorders in the central nervous system. Examples of these are myelomeningocele and holoprosencephaly. Three steps are important in clinical neuro-osteology: (1) clinical definition of the region of an osseous or dental malformation, (2) embryological determination of the origin of that region and recollection of which neurological structure has developed from the same region, and (3) clinical diagnosis of this neurological structure. If neurological malformation is the first symptom, step 2 results in the determination of the osseous region involved, which in step 3 is analyzed clinically. The relevance of future neuro-osteological diagnostics is emphasized.