I want to remove the "New" option in the entry in the main menu. Its small right arrow, which allows the user to see this menu at all, I would completely delete with this.

Here's what the element looks like in my site map:
<SubArea Id="nav_cases" Entity="incident"
DescriptionResourceId="Cases_SubArea_Description"
GetStartedPanePath="Cases_Web_User_Visor.html"
GetStartedPanePathAdmin="Cases_Web_Admin_Visor.html"
GetStartedPanePathOutlook="Cases_Outlook_User_Visor.html"
GetStartedPanePathAdminOutlook="Cases_Outlook_Admin_Visor.html" />
And based on the documentation on the sitemap I don’t think I can achieve this with xml.
So, I think I want to know if this is possible? Or is it just part of the framework that I can’t get into? Is there any smart javascript I can do?
The reason I want to remove it is because they are children in the parent: child relations, and we want users to create them from the context of the parent record.