Incidence and risk of antiresorptive agent-related osteonecrosis of the jaw (ARONJ) after tooth extraction in patients with autoimmune disease.

INTRODUCTION: Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a rare but serious complication in patients receiving antiresorprtive agents (AR). However, the incidence of ARONJ after tooth extraction in patients with autoimmune disease (AID) remains unclear. The present study aimed to clarify the high-risk population of ARONJ in patients with AID. MATERIALS AND METHODS: The study population comprised 232 patients treated with AR, AID or non-AID, who had undergone dental extraction from January 2011 to September 2017. The incidence and risk factors of ARONJ were analysed retrospectively. Additionally, the relationship between ARONJ and osteoporotic fracture (OF) and AR discontinuation during dental procedures was investigated. RESULTS: Of 232 patients, 10 developed ARONJ within 1 year of dental extraction. The incidence of ARONJ in patients with AID was higher than that in non-AID patients (2.0/100 person-year vs 0.5/100 person-year; p = 0.03). Among the AID patients, RA patients had strikingly high incidence of ARONJ (3.6/100 person-year). The incidence of neither ARONJ nor OF significantly differed between patients who continued and discontinued AR in the perioperative period. CONCLUSION: Patients with AID who undergo dental extraction are at high risk of ARONJ. Discontinuation of AR would not significantly contribute to reduce the incidence of ARONJ in those patients.

Dyschromatosis symmetrica hereditaria with long hair on the forearms, hypo/hyperpigmented hair, and dental anomalies: report of a novel ADAR1 mutation.

We report on a father and his two children who are affected with dyschromatosis symmetrica hereditaria (DSH). Mutation analysis of ADAR1 gene demonstrated a novel splice acceptor site mutation in intron 10, IVS10-2A>C. The hair on the forearm of the affected father became longer, larger in diameter, and hypopigmented (white) after age 40 years. Hyperpigmented hair was also found in normal and hypopigmented skin. The colors of the hair and the skin did not correlate. Transmission electron micrography of cortical keratinocytes of the hair follicles showed that normal hair contained more keratinocytes than those of hyperpigmented and hypopigmented hair. The keratinocytes of the hyperpigmented hair were larger than those of normal and hypopigmented hair and those of the normal hair were larger than those of the hypopigmented hair. The affected daughter had dens evaginatus of the mandibular right second premolar and the son had dens invaginatus of the maxillary permanent lateral incisors. Expression of Adar1 gene during mouse tooth development is demonstrated.