diff --git a/modules/backend/classes/NavigationManager.php b/modules/backend/classes/NavigationManager.php
index f7abeec77..fcd04cef7 100644
--- a/modules/backend/classes/NavigationManager.php
+++ b/modules/backend/classes/NavigationManager.php
@@ -1,5 +1,6 @@
 <?php namespace Backend\Classes;
 
+use Event;
 use BackendAuth;
 use System\Classes\PluginManager;
 
@@ -86,6 +87,11 @@ class NavigationManager
             $this->registerMenuItems($id, $items);
         }
 
+        /*
+         * Extensibility
+         */
+        Event::fire('backend.menu.extendItems', [$this]);
+
         /*
          * Sort menu items
          */
@@ -157,25 +163,95 @@ class NavigationManager
             $this->items = [];
 
         foreach ($definitions as $code => $definition) {
-            $item = (object)array_merge(self::$mainItemDefaults, array_merge($definition, [
-                'code' => $code,
+            $item = (object) array_merge(self::$mainItemDefaults, array_merge($definition, [
+                'code'  => $code,
                 'owner' => $owner
             ]));
 
             foreach ($item->sideMenu as $sideMenuItemCode => $sideMenuDefinition) {
-                $item->sideMenu[$sideMenuItemCode] = (object)array_merge(
+                $item->sideMenu[$sideMenuItemCode] = (object) array_merge(
                     self::$sideItemDefaults,
                     array_merge($sideMenuDefinition, [
-                        'code' => $sideMenuItemCode,
+                        'code'  => $sideMenuItemCode,
                         'owner' => $owner
                     ])
                 );
             }
 
-            $this->items[] = $item;
+            $itemKey = $this->makeItemKey($owner, $code);
+            $this->items[$itemKey] = $item;
         }
     }
 
+    /**
+     * Dynamically add an array of main menu items
+     * @param string $owner
+     * @param array  $definitions
+     */
+    public function addMainMenuItems($owner, array $definitions)
+    {
+        foreach ($definitions as $code => $definition)
+            $this->addMainMenuItem($owner, $code, $definition);
+    }
+
+    /**
+     * Dynamically add a single main menu item
+     * @param string $owner
+     * @param string $code
+     * @param array  $definitions
+     */
+    public function addMainMenuItem($owner, $code, array $definition)
+    {
+        $sideMenu = isset($definition['sideMenu']) ? $definition['sideMenu'] : null;
+
+        $itemKey = $this->makeItemKey($owner, $code);
+        if (isset($this->items[$itemKey]))
+            $definition = array_merge((array) $this->items[$itemKey], $definition);
+
+        $item = (object) array_merge(self::$mainItemDefaults, array_merge($definition, [
+            'code'  => $code,
+            'owner' => $owner
+        ]));
+
+        $this->items[$itemKey] = $item;
+
+        if ($sideMenu !== null)
+            $this->addSideMenuItems($sideMenu);
+    }
+
+    /**
+     * Dynamically add an array of side menu items
+     * @param string $owner
+     * @param string $code
+     * @param array  $definitions
+     */
+    public function addSideMenuItems($owner, $code, array $definitions)
+    {
+        foreach ($definitions as $sideCode => $definition)
+            $this->addSideMenuItem($owner, $code, $sideCode, $definition);
+    }
+
+    /**
+     * Dynamically add a single side menu item
+     * @param string $owner
+     * @param string $code
+     * @param string $sideCode
+     * @param array  $definitions
+     */
+    public function addSideMenuItem($owner, $code, $sideCode, array $definition)
+    {
+        $itemKey = $this->makeItemKey($owner, $code);
+        if (!isset($this->items[$itemKey]))
+            return false;
+
+        $mainItem = $this->items[$itemKey];
+        if (isset($mainItem->sideMenu[$sideCode]))
+            $definition = array_merge((array) $mainItem->sideMenu[$sideCode], $definition);
+
+        $item = (object) array_merge(self::$sideItemDefaults, $definition);
+        $this->items[$itemKey]->sideMenu[$sideCode] = $item;
+    }
+
     /**
      * Returns a list of the main menu items.
      * @return array
@@ -267,7 +343,7 @@ class NavigationManager
      * Specifies a code of the side menu item in the current navigation context.
      * @param string @sideMenuItemCode Specifies the side menu item code
      */
-    public function setContextSideMenu($sideMenuItemCode) 
+    public function setContextSideMenu($sideMenuItemCode)
     {
         $this->contextSideMenuItemCode = $sideMenuItemCode;
     }
@@ -309,4 +385,14 @@ class NavigationManager
 
         return $items;
     }
+
+    /**
+     * Internal method to make a unique key for an item.
+     * @param  object $item
+     * @return string
+     */
+    private function makeItemKey($owner, $code)
+    {
+        return strtoupper($owner).'.'.strtoupper($code);
+    }
 }
\ No newline at end of file