Classification and management of chronic sialadenitis of the parotid gland

Saliva has numerous oral functions and multiple functions in relation to digestion in the upper gastrointestinal tract. Chronic salivary hypofunction can lead to severe adverse health outcomes. Chronic sialadenitis is one of the major conditions that can cause salivary hypofunction. A correct diagnosis and management of chronic sialadenitis is essential for the recovery of salivary hypofunction. Chronic sialadenitis of the parotid gland is often seen in the clinic, sometimes also referred to as recurrent pyogenic parotitis, recurrent parotitis, non-obstructive parotitis, sialadenitis or obstructive parotitis, among other terms. The literature describes several different classifications and denominations for chronic sialadenitis of the parotid gland. These various classifications and denominations complicate the definition and diagnostic criteria, and if chronic sialadenitis of the parotid gland can develop into Sjogren's syndrome remains unclear. Treatment of this condition is also a challenging problem. Here, we review the presented classification and denomination of chronic sialadenitis of the parotid gland, proposing a classification based on the disease entities identified in a long-term follow-up investigation, and discuss the treatment principles for the condition.