Structured Objective: The purpose of this study was to systematically characterize individuals with short root anomaly (SRA) without any history of orthodontic treatment. The long‐term objective of the study was to improve diagnosis and treatment planning and determine risk factors for developing SRA.Setting and Sample Population: Twenty‐seven patients including two families and 16 unrelated individuals from (9–48 years) reported to orthodontic and/or dental practitioners within the USA.Materials and Methods: Digital panoramic and periapical films were analyzed to document pattern and frequency of SRA‐affected teeth. Crown‐to‐root (CR) ratios of the affected teeth were used to characterize the extent of malformation. Pedigree analysis by inspection was completed for one family to determine pattern of inheritance.Results: Twenty‐six of the twenty‐seven individuals were of Latino descent, and one was of Filipino descent. Hard tissues including enamel, dentin, pulp chambers and canals, and surrounding soft tissues were normal. We found that 25 of 27 individuals had localized SRA and two Latino individuals had generalized SRA. Teeth were affected bilaterally with maxillary central incisors (~63%) and mandibular second premolars most commonly involved (~33%). Affected teeth had a distinct, similar radiographic appearance; in the generalized cases, there was a more severe affection with larger (~twice) CR ratios. Ninety‐four percent of affected individuals did not show a significant difference in the CR ratios at different ages. Pedigree analysis suggests an autosomal dominant inheritance pattern in one family.Conclusion: This is the first report to show that SRA occurs more frequently in Latino individuals and has a predilection for anterior teeth. The occurrence of SRA in two families further confirms a hereditary component and supports a distinct nosology and nomenclature, hereditary idiopathic root malformation (HIRM) and warrants further investigation.

The study objective was to investigate the effects of fluoride on intact parathyroid hormone (iPTH) secretion. Thyro-parathyroid complexes (TPC) from C3H (n = 18) and B6 (n = 18) mice were cultured in Ca²⁺-optimized medium. TPC were treated with 0, 250, or 500 µM NaF for 24 h and secreted iPTH assayed by ELISA. C3H (n = 78) and B6 (n = 78) mice were gavaged once with distilled or fluoride (0.001 mg [F^-]/g of body weight) water. At serial time points (0.5-96 h) serum iPTH, fluoride, total calcium, phosphorus, and magnesium levels were determined. Expression of genes involved in mineral regulation via the bone-parathyroid-kidney (BPK) axis, such as parathyroid hormone (Pth), calcium-sensing receptor (Casr), vitamin D receptor (Vdr), parathyroid hormone-like hormone (Pthlh), fibroblast growth factor 23 (Fgf23), α-Klotho (αKlotho), fibroblast growth factor receptor 1c (Fgf1rc), tumor necrosis factor 11 (Tnfs11), parathyroid hormone receptor 1 (Pth1r), solute carrier family 34 member 1 (Slc34a1), solute carrier 9 member 3 regulator 1 (Slc9a3r1), chloride channel 5 (Clcn5), and PDZ domain-containing 1 (Pdzk1), was determined in TPC, humeri, and kidneys at 24 h. An in vitro decrease in iPTH was seen in C3H and B6 TPC at 500 µM (p < 0.001). In vivo levels of serum fluoride peaked at 0.5 h in both C3H (p = 0.002) and B6 (p = 0.01). In C3H, iPTH decreased at 24 h (p < 0.0001), returning to baseline at 48 h. In B6, iPTH increased at 12 h (p < 0.001), returning to baseline at 24 h. Serum total calcium, phosphorus, and magnesium levels did not change significantly. Pth, Casr,αKlotho,Fgf1rc,Vdr, and Pthlh were significantly upregulated in C3H TPC compared to B6. In conclusion, the effects of fluoride on TPC in vitro were equivalent between the 2 mouse strains. However, fluoride demonstrated an early strain-dependent effect on iPTH secretion in vivo. Both strains demonstrated differences in the expression of genes involved in the BPK axis, suggesting a possible role in the physiologic handling of fluoride.

This study aimed to find the set of risk indicators best able to predict root caries (RC) incidence in caries-active adults utilizing data from the Xylitol for Adult Caries Trial (X-ACT). Five logistic regression models were compared with respect to their predictive performance for incident RC using data from placebo-control participants with exposed root surfaces at baseline and from two study centers with ancillary data collection (n = 155). Prediction performance was assessed from baseline variables and after including ancillary variables [smoking, diet, use of removable partial dentures (RPD), toothbrush use, income, education, and dental insurance]. A sensitivity analysis added treatment to the models for both the control and treatment participants (n = 301) to predict RC for the control participants. Forty-nine percent of the control participants had incident RC. The model including the number of follow-up years at risk, the number of root surfaces at risk, RC index, gender, race, age, and smoking resulted in the best prediction performance, having the highest AUC and lowest Brier score. The sensitivity analysis supported the primary analysis and gave slightly better performance summary measures. The set of risk indicators best able to predict RC incidence included an increased number of root surfaces at risk and increased RC index at baseline, followed by white race and nonsmoking, which were strong nonsignificant predictors. Gender, age, and increased number of follow-up years at risk, while included in the model, were also not statistically significant. The inclusion of health, diet, RPD use, toothbrush use, income, education, and dental insurance variables did not improve the prediction performance.