Three.js - Set imported .obj as mesh and not linesegments

Question

I am importing a obj + mtl file (exported from blender) in my three.js project. The problem is that i get a linesegments object (buffergeometry+linesegment material) instead of a mesh. How can i solve this?

This is my code:

var mtlLoader= new THREE.MTLLoader();
mtlLoader.load( 
'http://localhost/planegeometryeditor/meshes/map/firstterrain.mtl', 
 function(materials) {
    materials.preload();
var objLoader= new THREE.OBJLoader();
objLoader.setMaterials(materials);
objLoader.load(
       'http://localhost/planegeometryeditor/meshes/map/firstterrain.obj', 
   function(object) { scene.add(object); }
   null, 
   null
);
 }
 );