Calcium hydroxylapatite filler: an overview of safety and tolerability.

Soft tissue fillers are becoming increasingly important as nonsurgical treatment options for facial rejuvenation. Calcium hydroxylapatite (CaHA) is an injectable dermal filler that contains uniform CaHA microspheres suspended in an aqueous carboxymethylcellulose gel carrier. It is considered a long-lasting, but non-permanent filler, and is highly biocompatible with human tissue. No osteogenesis has been reported in extensive literature describing the use of CaHA in a variety of soft tissue applications. Injection of CaHA into the oral mucosa and the lips is an unapproved indication and may result in nodule formation. This occurs soon after injection and is a result of accumulated particles and not a granulomatous reaction. As with all biodegradable dermal fillers, CaHA can be associated with rare incidences of foreign body reactions, but only a handful of case reports have been documented in 10 years of clinical use. CaHA can be associated with local, short-term, injection-related adverse events, which are generally mild and resolve within a few days. Clinical trials that have followed patients for up to 3 years post-injection report no long-term or delayed-onset adverse events. CaHA is an effective and safe treatment option for a variety of aesthetic indications. This paper focuses on common safety concerns of patients and aesthetic physicians, including unfounded fears of osteogenesis and foreign body granulomas, providing an up-to-date overview of the tolerability and long-term safety of CaHA for aesthetic indications.