Sir, we would like to contribute to the tips for management of dry mouth by Y. Lin et al.1 Besides general measures for the relief of oral dryness, they also provided a comprehensive list of local measures. However, a recent study in patients with Sjögren's disease showed significant differences in the efficacy of therapies in relieving dry mouth complaints.2 In line it is also important to realise that different causes of oral dryness can lead to differences in the perception of oral dryness between patients. Using the Regional Oral Dryness Inventory (RODI), we recently demonstrated that subgroups of dry mouth patients perceived different intra-oral regions as most dry.3 The use of dry-mouth interventions was related to this local severity of oral dryness. For example, the use of a mouth gel was significantly associated with dryness of the anterior of the tongue. Therefore, we hypothesise that by using the RODI, in combination with other parameters, it will be possible to give patients more individually tailored advice on the most appropriate interventions for relief of oral dryness symptoms.