Dental anomalies in first-degree relatives of transposed canine probands

"Examining the link between tooth agenesis and papillary thyroid cancer: is there a risk factor?" Observational study

BACKGROUND

Mutations in one or multiple genes can lead to hypodontia and its characteristic features. Numerous studies have shown a strong genetic influence on the occurrence of hypodontia, and identified several genes, including AXIN2, EDA, FGF3, FGFR2, FGFR10, WNT10A, MSX1, and PAX9, that are directly associated with dental agenesis and carcinogenesis. The objective of this study was to investigate the occurrence and pattern of tooth agenesis, microdontia, and palatally displaced canine (PDC) in women diagnosed with papillary thyroid cancer (PTC), compared to a control group of women without any malignancy or thyroid disease.

MATERIALS AND METHODS

This case-control study was carried at the Department of Orthodontics, School of Dental Medicine University of Zagreb, and Department of Oncology and Nuclear Medicine Sestre Milosrdnice University Hospital Centre. The study involved a clinical examination and evaluation of dental status, panoramic X-ray analysis, and assessment of medical and family history of 116 female patients aged 20-40 with PTC, as well as 424 females in the control group who were of similar age.

RESULTS

The prevalence of hypodontia, microdontia, and PDC was statistically higher in women with PTC than in the control group. The prevalence rate of hypodontia was 11.3% in the experimental group and 3.5% in the control group. The experimental group showed a higher occurrence of missing upper lateral incisors, lower left central incisors, and all the third molars (except the upper left) compared to the control group. Women with PTC showed the prevalence of PDC significantly higher than the control group (3.5%, 0.7%, p = 0.002). The probability of hypodontia as a clinical finding increases 2.6 times, and microdontia occurs 7.7 times more frequently in women with PTC.

CONCLUSION

Our study suggests a possible link between odontogenesis and PTC. The absence of permanent teeth may increase the likelihood of PTC in women. Leveraging the age-7 orthopantomogram to identify women at high risk for PTC within a critical early detection window could significantly improve oral health outcomes and PTC prognosis through proactive interventions.

Dental age estimation of young subjects with unilateral palatally displaced canine teeth

INTRODUCTION

Delayed tooth eruption is often seen in patients with palatally displaced canines (PDC), but there is controversy over whether tooth formation is also delayed. This study attempts to elucidate the answer by addressing methodological shortcomings in previous studies.

METHODS

Archived records were searched, and 100 patients (aged 8-16 years) with unilateral PDC were identified. Records of 50 women and 50 men were matched for age and sex with unaffected controls. The exclusion criteria included hypodontia. Dental age (DA) was calculated using the population-specific Maltese database and subtracted from the chronological age (CA). Nonparametric tests were used to compare CA-DA in patients with PDC and controls to determine the DA of end-of-series teeth.

RESULTS

No statistically significant difference with CA-DA between patients with PDC and controls was found. In addition, there were no particular teeth significantly delayed in development.

CONCLUSIONS

Unilateral PDC does not affect dental developmental age, and the end-of-series teeth investigated show no delay in development.

Transposition of Mandibular Molars in a Dog

Tooth transposition is a rare anomaly resulting in the interchanged position of 2 permanent teeth. Etiology of tooth transposition is unclear. In human dentistry, multiple influences are described, and there is strong evidence of a genetic basis. This is the first reported case of tooth transposition in a dog.

Second premolar agenesis is associated with mandibular form: a geometric morphometric analysis of mandibular cross-sections

The aim of this study was to compare mandibular form (i.e., size and shape) between patients with agenesis of the lower second premolar (P2) and a control group with no agenesis. Three hypotheses were tested: (H1) agenesis causes a change in mandibular morphology because of inadequate alveolar ridge development in the area of the missing tooth (mandibular plasticity); (H2) agenesis is caused by spatial limitations within the mandible (dental plasticity); and (H3) common genetic/epigenetic factors cause agenesis and affect mandibular form (pleiotropy). A geometric morphometric analysis was applied to cross-sectional images of computed tomography (CT) scans of three matched groups (n=50 each): (1) regularly erupted P2; (2) agenesis of P2 and the primary second molar in situ; and (3) agenesis of P2 and the primary second molar missing for >3 months. Cross-sections of the three areas of interest (first premolar, P2, first molar) were digitized with 23 landmarks and superimposed by a generalized Procrustes analysis. On average, the mandibular cross-sections were narrower and shorter in patients with P2 agenesis compared with that in the control group. Both agenesis groups featured a pronounced submandibular fossa. These differences extended at least one tooth beyond the agenesis-affected region. Taken together with the large interindividual variation that resulted in massively overlapping group distributions, these findings support genetic and/or epigenetic pleiotropy (H3) as the most likely origin of the observed covariation between mandibular form and odontogenesis. Clinically, reduced dimensions and greater variability of mandibular form, as well as a pronounced submandibular fossa, should be expected during the treatment planning of patients with P2 agenesis.