Dental anomalies of a child with incontinentia pigmenti: Case report

Incontinentia Pigmenti is a rare multi-system dominant genetic disorder caused by a mutation of the IKBKG/NEMO gene, localized on the X-chromosome, locus Xq28, characterized by dermatological, ocular, neurological, and dental alterations. This case report shows Incontinentia Pigmenti dental findings and emphasizes the importance of the dentist's knowledge about these anomalies so that the patient can be regularly monitored throughout the development of the dentition. Keywords: Child, Incontinentia Pigmenti, Tooth Abnormalities.

Skeletal Deformities in Osterix-Cre;Tgfbr2f/f Mice May Cause Postnatal Death

Transforming growth factor β (TGFβ) signaling plays an important role in skeletal development. We previously demonstrated that the loss of TGFβ receptor II (Tgfbr2) in Osterix-Cre-expressing mesenchyme results in defects in bones and teeth due to reduced proliferation and differentiation in pre-osteoblasts and pre-odontoblasts. These Osterix-Cre;Tgfbr2f/f mice typically die within approximately four weeks for unknown reasons. To investigate the cause of death, we performed extensive pathological analysis on Osterix-Cre- (Cre-), Osterix-Cre+;Tgfbr2f/wt (HET), and Osterix-Cre+;Tgfbr2f/f (CKO) mice. We also crossed Osterix-Cre mice with the ROSA26mTmG reporter line to identify potential off-target Cre expression. The findings recapitulated published skeletal and tooth abnormalities and revealed previously unreported osteochondral dysplasia throughout both the appendicular and axial skeletons in the CKO mice, including the calvaria. Alterations to the nasal area and teeth suggest a potentially reduced capacity to sense and process food, while off-target Cre expression in the gastrointestinal tract may indicate an inability to absorb nutrients. Additionally, altered nasal passages and unexplained changes in diaphragmatic muscle support the possibility of hypoxia. We conclude that these mice likely died due to a combination of breathing difficulties, malnutrition, and starvation resulting primarily from skeletal deformities that decreased their ability to sense, gather, and process food.

Oral manifestations of Alagille syndrome

Alagille syndrome (AGS) is a multisystem disorder classically involving liver and heart failure, characteristic vertebral and facial features and ocular abnormalities. AGS is caused by heterozygous mutations in JAG1 or NOTCH2, with variable phenotype penetrance. We report two cases of AGS in children with tooth defects characterised by green discolouration and hypomineralisation. The role of hyperbilirubinaemia (HB) in this atypical colour, a classical feature of AGS, has been well described. However, it does not totally explain the dental phenotype. As JAG1 and NOTCH2 mutations can affect bone development and considering common physiological pathways between bone and tooth mineralisation, both mutations could participate in this unusual dental phenotype. The role of HB and genetics in the development of the dental phenotype of AGS is discussed in two prototypical cases. Future research should focus on the underlying genetic component of tooth abnormalities.

Equine supernumerary molar tooth: A clinical case

The aim of this report is to present a clinical case of an additional tooth (dens suplementarius) in a 13-year-old thoroughbred mare currently used for pleasure riding. She was referred for specific dental evaluation because of recurrent nasal discharge that started to change from mucous to mucopurulent. The first attempt to remove the additional tooth was performed on the standing horse, but was unsuccessful because of the location of the problem. Surgical procedures under general anaesthesia, that is, trepanation of the nasofrontal sinus and “sinus flap,” succeeded. The mare was under antimicrobial therapy for 7 days after the surgery and received NSAID drugs for 2 more days. Medical dressing was removed 2 days after the surgery, and sinus flush with Foleys catheter was performed during 8 days after removing the dressing. The mare returned to previous work soon after the surgical procedure. Dental problems are among the most common in field veterinary practice, but supernumerary teeth occur in only a small percentage of horses. Cases of such tooth abnormalities are usually detected in the early or middle age of an animal during a regular dental examination or when the situation starts to create clinical problems. A suspicion of an additional tooth should always be confirmed by imaging diagnostics. In most cases, radiological evaluation is enough to confirm the diagnosis and asses the situation before selecting a specific medical solution.

The Biology Underlying Abnormalities of Tooth Number in Humans

In past decades, morphologic, molecular, and cellular mechanisms that govern tooth development have been extensively studied. These studies demonstrated that the same signaling pathways regulate development of the primary and successional teeth. Mutations of these pathways lead to abnormalities in tooth development and number, including aberrant tooth shape, tooth agenesis, and formation of extra teeth. Here, we summarize the current knowledge on the development of the primary and successional teeth in animal models and describe some of the common tooth abnormalities in humans.

Tooth Abnormalities and Occlusal Disorders in Individuals with Frontonasal Dysplasia

Objective Frontonasal dysplasia is a rare developmental defect of the midface, and little is known about the dental involvement in individuals with this condition. This study investigated tooth abnormalities and occlusal disorders in individuals with frontonasal dysplasia. Design Cross-sectional. Setting Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, Bauru, Brazil. Interventions Clinical oral examination, analysis of patient records, and panoramic radiographs. Participants A total of 20 individuals with frontonasal dysplasia aged 7 to 17 years. Main Outcome Measures Prevalence of the several tooth abnormalities and occlusal disorders analyzed. Results A total of 19 individuals presented at least one tooth abnormality, with highly variable findings. In radiographs, 20% of individuals (all presenting oral clefts) presented agenesis of lateral incisors and second premolars. No supernumerary teeth were observed; 65% of individuals exhibited occlusal alterations, especially anterior open bite in the two individuals with median cleft lip. Conclusions Variable clinical and radiographic alterations were observed, probably due to the large variety of phenotypic characteristics. No specific dental alteration could be related with frontonasal dysplasia.

Tooth abnormalities in pediatric patients submitted to antineoplastic treatment for central nervous system neoplasms

<strong>Objective</strong>: The aim of this study was to evaluate the frequency of tooth abnormalities in pediatric patients treated for central nervous system neoplasms. <strong>Material and methods: </strong>This cross-sectional study assessed thirty-one patients, median age 14.2 years (range 5 - 25), who were off therapy for at least one year, comparatively with a control group of thirty-one healthy patients matched for age with the study group. Tooth abnormalities were evaluated by panoramic radiographs. <strong>Results: </strong>There was no statistical significant evidence that patients of the study group (age range 5 - 25 years) have more frequency of tooth abnormalities comparatively with controls. However, in children who were diagnosed before 5 years of age, microdontia was the most common abnormality with statistically significant difference (<em>P=</em>0.037). Root shortening grade III was observed in patients over 10 years of age at the time of radiographic examination, also with statistical significance (<em>P=</em>0.046). <strong>Conclusions: </strong>Tooth abnormalities frequency in patients treated for central nervous system neoplasms is directly related to the age of diagnosis and stage of odontogenesis. Microdontia and reduced root surface areas, the most common abnormalities observed, can lead to future oral health impairment due to malocclusion and less periodontal support. It is important to give parents and patients early orientation about maintenance of good oral hygiene and proper treatment by orthodontics or dentofacial orthopedics.