Taurodontism and Van der Woude syndrome. Is there an association?

Co-Occurrence of Taurodontism in Nonsyndromic Cleft Lip and Palate Patients in Subset of Indian Population: A Case-Control Study Using CBCT

The present study aimed to assess the co-occurrence of taurodontism in nonsyndromic cleft lip and palate (NSCLP) patients in a subset of Indian population using cone beam computed tomography (CBCT).

The study was a retrospective case-control kinds assessing 1500 CBCT scans over a period of 2 years; 67 scans out of 1500 showed cleft lip and palate (CLP). After fulfilling the inclusion and exclusion criteria, 38 subjects out of 67 comprised the case group; 80 randomly selected subjects constituted the control group. The first and second permanent molars in both the arches (8 teeth) of each subject were assessed for the presence and severity of taurodontism using the objective criteria. Statistical analysis was done using the χ2 test. Inter and intraobserver agreement was evaluated by Kappa statistics.

71.05% subjects showed taurodontism in case group, while 45% subjects showed its presence in control group; results being significant for both the groups. However, the comparison of number of teeth with taurodontism in the 2 groups came out to be statistically insignificant. Also no significant association of taurodontism was seen with gender or the different types of cleft (P = .437). Hypotaurodontism was the most prevalent type.

There was a higher prevalence of taurodontism in both groups which had been underestimated in the previous studies. This emphasizes the significance of the use of CBCT in detection of dental anomalies which would otherwise go undetected.

Taurodontism in the first permanent molars in Van der Woude syndrome compared to isolated cleft palate

OBJECTIVES

To analyse prevalence, pattern, and severity of taurodontism in individuals with Van der Woude syndrome (VWS) exhibiting cleft palate and compare with aged-matched non-syndromic cleft palate (NSCP) and non-cleft controls.

MATERIALS AND METHODS

One hundred and seventy-eight dental panoramic tomographs (DPTs) (105 girls and 73 boys) consisting of 42 VWS patients (x¯=8.55±1.02 years), 42 NSCP patients (x¯=8.59±1.02 years), and 94 normative non-cleft children (x¯=8.79±1.16 years) were assessed and their first permanent molars evaluated. Measurement 3 of the taurodontism index developed by Shifman and Chanannel with the Tulensalo modification was used. Prevalence, pattern, and severity were compared between groups. Statistical differences were determined by one-way analysis of variance and Fisher test. Repeatability was calculated by Cohens Kappa test.

RESULTS

The prevalence of taurodontic molars was 59.5% in VWS, 45.2% in NSCP, and 26.6% in non-cleft controls. The prevalence and severity of taurodontism in VWS and NSCP were significantly higher than in non-cleft children in all first permanent molars. There was no significant difference in prevalence and severity between VWS and NSCP. The odds for having taurodontism in the VWS group was approximately double compared to the NSCP group. Most of the taurodontic molars showed hypotaurodontism and taurodontism occurred bilaterally more frequently than unilaterally.

CONCLUSION

This study shows a higher prevalence of taurodontism in VWS and NSCP. Most taurodontic molars are hypotaurodontic and most occur bilaterally.

Rare Diseases of the Oral Cavity, Neck, and Pharynx

Diseases occurring with an incidence of less than 1-10 cases per 10 000 individuals are considered as rare. Currently, between 5 000 and 8 000 rare or orphan diseases are known, every year about 250 rare diseases are newly described. Many of those pathologies concern the head and neck area. In many cases, a long time is required to diagnose an orphan disease. The lives of patients who are affected by those diseases are often determined by medical consultations and inpatient stays. Most orphan diseases are of genetic origin and cannot be cured despite medical progress. However, during the last years, the perception of and the knowledge about rare diseases has increased also due to the fact that publicly available databases have been created and self-help groups have been established which foster the autonomy of affected people. Only recently, innovative technical progress in the field of biogenetics allows individually characterizing the genetic origin of rare diseases in single patients. Based on this, it should be possible in the near future to elaborate tailored treatment concepts for patients suffering from rare diseases in the sense of translational and personalized medicine. This article deals with orphan diseases of the lip, oral cavity, pharynx, and cervical soft tissues depicting these developments. The readers will be provided with a compact overview about selected diseases of these anatomical regions. References to further information for medical staff and affected patients support deeper knowledge and lead to the current state of knowledge in this highly dynamic field.

Prevalence of Taurodont Molars in a Selected Iranian Adult Population

Introduction:

Taurodontism is an anomaly characterized by elongated crowns and consumedly apical location of the bifurcation area. This study aimed to determine the prevalence of taurodontism in molars based on digital panoramic radiographies in eight cities of Iran.

Methods and Materials:

This descriptive cross-sectional study was conducted on 2360 digital panoramic radiographs taken for different treatment purposes. Demographic information of patients was recorded and radiographs were evaluated for presence of taurodont molars. The prevalence rates were calculated and the data were analyzed using SPSS software version 18 via paired t-test, chi square test and ANOVA.

Results:

A total of 2360 panoramic radiographs (from 51.4% male and 48.6% female patients) were evaluated and the prevalence of taurodontism was reported 22.9% (22.6% in males and 23.3% in females) (P>0.05). Its prevalence was 51.67% in the right and 48.33% in the left quadrants (P>0.05), 34.1% in the mandible and 65.9% in the maxilla (P=0.000) and 79.52% in the second and 20.48% in the first molar (P=0.000). The prevalence of hypotaurodontism, mesotaurodontism and hypertaurodontism was 84.13%, 11.07% and 4.8%, respectively.

Conclusion:

The prevalence of taurodont molars was high in Iran and it was more common in the second molars and in the maxilla. Hypotaurodontism had the highest prevalence.

Full Spectrum of Postnatal Tooth Phenotypes in a Novel Irf6 Cleft Lip Model

Clefting of the lip, with or without palatal involvement (CLP), is associated with a higher incidence of developmental tooth abnormalities, including hypodontia and supernumerary teeth, aberrant crown and root morphologies, and enamel defects, although the underlying mechanistic link is poorly understood. As most CLP genes are expressed throughout the oral epithelium, the authors hypothesized that the expression of CLP genes may persist in the dental epithelium and thus, in addition to their earlier role in labiopalatine development, may play an important functional role in subsequent tooth patterning and amelogenesis. To address this, the authors generated a unique conditional knockout model involving the major CLP gene, Irf6, that overcomes the previously reported perinatal lethality to enable assessment of any posteruption dental phenotypes. A dental epithelium-specific Irf6 conditional knockout (Irf6-cKO) mouse was generated via a Pitx2-Cre driver line. Dental development was analyzed by microcomputed tomography, scanning electron microscopy, histology, immunohistochemistry, and quantitative polymerase chain reaction. Irf6-cKO mice displayed variable hypodontia, occasional supernumerary incisors and molars, as well as crown and root patterning anomalies, including peg-shaped first molars and taurodontic and C-shaped mandibular second molars. Enamel density was reduced in preeruption Irf6-cKO mice, and some shearing of enamel rods was noted in posteruption incisors. There was also rapid attrition of Irf6-cKO molars following eruption. Histologically, Irf6-cKO ameloblasts exhibited disturbances in adhesion and polarity, and delayed enamel formation was confirmed immunohistochemically. Altered structure of Hertwig's epithelial root sheath was also observed. These data support a role for IRF6 in tooth number, crown and root morphology and amelogenesis that is likely due to a functional role of Irf6 in organization and polarity of epithelial cell types. This data reinforce the notion that various isolated tooth defects could be considered part of the CLP spectrum in relatives of an affected individual.

Prevalence of Taurodont molars in a North Indian population

BACKGROUND

It is very important for dentists to be familiar with anomalies of teeth not only for the clinical complications but also their management. Taurodontism also provides a valuable clue in detecting its association with various syndromes and other systemic conditions. The purpose of this study was to assess the prevalence of Taurodont molars among a North Indian population.

MATERIALS AND METHODS

A total of 1000 patients' full-mouth periapical radiographs were screened. The radiographs were evaluated under optimal conditions using double magnifying glasses. A total of 7615 molars (including third molars) were evaluated. The relative incidence and the correlations regarding the location of Taurodont teeth (right versus left side and maxillary versus mandibular) were analyzed using the Chi-square test.

RESULTS

Twenty-eight patients were found to have a Taurodont molar (11 women and 17 men [P = 0.250]). The prevalence of Taurodont molar was 2.8%. Males had a higher prevalence rate than females (3.4% vs. 2.2%, respectively). A cluster analysis of total Taurodonts in the mandible (45%) versus maxilla (55%) of both males and females combined showed a statistically significant difference (P < 0.05).

CONCLUSION

The occurrence of Taurodontism is basically based on racial expression in different populations. These variations in prevalence between different populations may be due to ethnic variations. The occurrence of Taurodont molars among this Indian population was rare.

Craniofacial morphology in children with van der Woude syndrome and isolated cleft palate

OBJECTIVE

To compare cephalometrically 6-year-old children with van der Woude syndrome and cleft palate (VWS) to children with isolated cleft palate alone (CP).

DESIGN

A retrospective case-control study.

PATIENTS AND SETTING

Forty-four children with VWS were compared to 73 children with CP using lateral cephalograms. The mean age of the children with VWS was 6.6 years (range = 5.9-8.2) and that of the children with CP, 6.2 years (range = 5.7-6.7). Palatal closure had been done at a mean age of 1.4 years (range = 0.8-2.2), mostly with the Veau-Wardill-Killner or the Cronin pushback surgical techniques. The data was collected over a 30-year period.

MAIN OUTCOME MEASURE

Linear and angular measurements were obtained from lateral cephalograms. A Student's t-test was used in the statistical analysis.

RESULTS

The craniofacial morphology in children with VWS and CP was similar, but those with VWS had slightly smaller diameters of the lower pharyngeal airway. The maxilla and mandible were well related to each other, although a little retrusive in relation to the cranial base. The soft tissue profile reflected the skeletal relationships, no significant protrusion of the lower lip was noted.

CONCLUSIONS

Six-year-old children with VWS and CP have similar craniofacial morphology.

Taurodontism: A minor diagnostic criterion in Laurence-Moon/Bardet-Biedl syndromes

OBJECTIVE

The objective of the study was to present the prevalence of taurodontism in the permanent dentition in individuals with Laurence-Moon/Bardet-Biedl syndromes (LM/BBS).

METHODS AND PARTICIPANTS

Thirty-nine individuals were studied, which comprises the whole population of known LM/BBS patients in Norway. Data were collected retrospectively. Panoramic radiographs (OPG) were evaluated to document taurodontism.

RESULTS

Taurodontism was found in 82.9% of the individuals with LM/BBS. The second mandibular molars had the highest (72.3%) prevalence of taurodontism and the first mandibular molars the lowest (58.2%).

CONCLUSION

This study suggests that taurodontism should be included as a minor diagnostic criterion for the Laurence-Moon/Bardet-Biedl syndromes (LM/BBS).

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.

Prevalence of taurodontism in the North Indian population

OBJECTIVES

Taurodontism affects primarily molars and premolars in both the deciduous and permanent dentition. The aim of the study was to assess the prevalence of taurodontism in the North Indian population.

STUDY DESIGN

4143 patients were studied by analyzing the panoramic radiographs for the presence of taurodontism which is defined as the presence of an apically displaced pulp chamber and the tooth lacks the usual constriction at the cementoenamel junction. The age of the patients ranged from 13 to 38 years with a mean age of 21.8 years.

RESULTS

Taurodontism was found in 17 patients with a prevalence of 0.4% of which 0.21% were males and 0.19% females. Taurodonts were significantly more common in the maxilla (65.6%) than in the mandible (34.4%) (p<0.05) and the maxillary second molar (34.4%) was the most commonly involved tooth. According to the morphology hypotaurodonts were most common (75%) but there was no significant difference in males and females (p>0.05).

CONCLUSION

Taurodontism is relatively uncommon in the North Indian population. Further large scale studies need to be carried out to assess its prevalence in the general population. A family history of other anomalies should also be considered for affected patients. Key words:Taurodontism, prevalence, maxillary second molar.

Prevalence of taurodontism in premolars and molars in the South of iran

Background and aims

The study was undertaken to assess the prevalence of taurodontism and related systemic condi-tions and gender differences in premolars and molars of patients attending Shiraz Faculty of Dentistry.

Materials and methods

In this cross-sectional study, panoramic radiographs of 510 randomly selected patients were evaluated by a maxillofacial radiologist for the apically displaced pulp chamber. Detailed medical and family history of the patients was obtained.

Results

The prevalence of taurodontism in 510 panoramic views was 5.5% of patients. Females had significantly higher prevalence of taurodontism than men (P>0.05) and mandibular second molar was the most affected tooth.

Conclusion

Taurodontism was relatively common in population under study. A family history of other anomalies should be checked for affected patients.

The role of Irf6 in tooth epithelial invagination

Thickening and the subsequent invagination of the epithelium are an important initial step in ectodermal organ development. Ikkα has been shown to play a critical role in controlling epithelial growth, since Ikkα mutant mice show protrusions (evaginations) of incisor tooth, whisker and hair follicle epithelium rather than invagination. We show here that mutation of the Interferon regulatory factor (Irf) family, Irf6 also results in evagination of incisor epithelium. In common with Ikkα mutants, Irf6 mutant evagination occurs in a NF-κB-independent manner and shows the same molecular changes as those in Ikkα mutants. Irf6 thus also plays a critical role in regulating epithelial invagination. In addition, we also found that canonical Wnt signaling is upregulated in evaginated incisor epithelium of both Ikkα and Irf6 mutant embryos.

Imaging evalution of the gingival fibromatosis and dental abnormalities syndrome

OBJECTIVE

The purpose of this study was to evaluate the dentomaxillofacial imaging features of one family affected by the gingival fibromatosis (GF) and dental abnormalities (DA) syndrome.

METHODS

Conventional radiographs (periapical and panoramic) and cone beam CT (CBCT) were performed in nine members of this family: four were affected by the syndrome and five were not.

RESULTS

The four affected members demonstrated mild generalized GF in association with DA, including hypoplastic amelogenesis imperfecta, intrapulpal calcifications, delay on tooth eruption and pericoronal radiolucencies in unerupted teeth. None of these oral changes were identified in the five unaffected members. All nine members presented alterations in the paranasal sinuses and mucosal thickening of the maxillary sinus was the most common finding.

CONCLUSION

Family members not affected by the syndrome showed similar alterations in the paranasal sinuses and CBCT was useful to characterize the dentomaxillofacial features of this new syndrome associating GF and DA.