This paper introduces a test-pattern named a dense component for checking inconsistencies in the hierarchical structure of a wordnet. Dense component (viewed as substructure) points out the cases of regular polysemy in the context of multiple inheritance. Definition of the regular polysemy is redefined ― instead of lexical units there are used lexical concepts (synsets). All dense components are evaluated by expert lexicographer. Based on this experiment we give an overview of the inconsistencies which the test-pattern helps to detect. Special attention is turned to all different kind of corrections made by lexicographer. Authors of this paper find that the greatest benefit of the use of dense components is helping to detect if the regular polysemy is justified or not. In-depth analysis has been performed for Estonian Wordnet Version 66. Some comparative figures are also given for the Estonian Wordnet (EstWN) Version 67 and Princeton WordNet (PrWN) Version 3.1. Analysing hierarchies only hypernym-relations are used.