comb over vs fine-tooth comb

comb over

verb
  • to examine scrupulously 

fine-tooth comb

verb
  • To search (something or somewhere) meticulously. 

noun
  • A means of making a thorough search. 

  • A comb with fine, closely spaced teeth, especially one used for removing head lice and their nits (eggs) from the hair; a nit comb. 

How often have the words comb over and fine-tooth comb occurred in a corpus of books? (source: Google Ngram Viewer )