Most Common Site of Sialadenitis
The parotid gland is the most common site of sialadenitis, accounting for the majority of bacterial sialadenitis cases. 1
Anatomic Distribution by Gland Type
Parotid Gland (Most Common Overall)
- The parotid gland is most commonly involved in bacterial sialadenitis, representing the predominant site of infection 1
- The parotid glands are the largest salivary glands and produce aqueous serous secretions that are less immunogenic, making them more susceptible to infections 2
- In pediatric populations, viral parotitis and juvenile recurrent parotitis affecting the parotid gland are the two most common causes of sialadenitis 3
Submandibular Gland (Most Common for Obstructive Disease)
- The submandibular glands are responsible for more than 80% of salivary stones, making them the most common site for obstructive sialadenitis 2
- The submandibular glands produce mucinous secretions high in calcium and phosphate salts through a long submandibular duct (Wharton's duct) that flows against gravity, predisposing to stone formation 2
- In post-surgical contexts, particularly following skull base neurosurgery, the submandibular gland is the stereotypical site affected, with swelling occurring contralateral to the craniotomy site within 4 hours of surgical closure 4, 5
Clinical Context Matters
Infectious Sialadenitis
- Staphylococcus aureus is the most common bacterial cause, typically affecting the parotid gland 6, 2
- Paramyxovirus (mumps) is the common viral cause, also predominantly affecting the parotid gland 6
Obstructive Sialadenitis
- Sialolithiasis causes up to 50% of all salivary gland disorders and predominantly affects the submandibular gland due to its anatomic and biochemical characteristics 2
- Mechanical compression of Wharton's duct during prolonged head and neck positioning can lead to submandibular sialadenitis, particularly in surgical settings 5
Autoimmune Sialadenitis
- In Sjögren syndrome, parotid glands show lymphoepithelial sialadenitis more frequently than minor salivary glands 7
Key Clinical Pitfall
Do not assume all sialadenitis is parotid-based—while the parotid is most common for infectious causes, the submandibular gland dominates in obstructive disease, which represents a substantial proportion of cases given that sialolithiasis causes up to 50% of salivary gland disorders 2.