Oscar throat sexing? (sounds wrong i know)

[Eläköön]

basically i was observing my oscars earlier as they are a pair but have yet to lay so im not sure which is which, however they are a foot long so its not like theyre only babies.

i remember reading that a certain fish is sexed by its lower jaw structure specifically the Mandible (maybe its snakeheads) anyway both of my oscars have a different jaw structure.
the bigger one has 2 lines that meet in the middle joined to the gills,
the other one has the same 2 lines but a large gap inbetween with more skin between. is this just variation or have i found a reliable way to sex oscars?

 

[steelshade]

I haven't heard of this, but I'm interested in finding if it is true.

 

[Eläköön]

anybody else who has a pair of oscars please look at this for me and if possible take some pictures so we can see if this is the trick to sexing these guys easily

 

[[enjoyable_attempt]]

Just take em out and look at thier vents.

 

[Eläköön]

this isnt about sexing MY oscars this is about possibly finding a way to help distinguish metamorphical differences between the sexes of oscars, something that until now wasnt really possible, if of course this is correct