39. Select the faces and Detach them.
40. Hide the remaining mesh.
41. Select Polygon as sub-object, then use inset (Shift + i) and make it as next image
42. Now push this faces some units above and use Bevel (Shift + b).
43. Unhide all mesh and select the big mesh (the edited) and attach it at the "gum" and after use Weld (Shift + w) in sub-object vertex, use the value 1.
44. Now select the vertexes as image 092 and use Connect (Shift + n).
45. If you pay attention to the model, you will see that we have an additional tooth, so we're going to delete the faces as image 093 and close this "hole". Organize the vertexes.
46. The model should be as image 094.
47. Some details aren't good yet, we're going to fix them then.
48. I disable "See Through" to edit the model.
49. Remove the red edge, you can use the Remove tool in Panel Editable Poly (Remove don't delete edges, this is similar to the "invisible" of the Editable Mesh, it hides edge only.
50. Ok, we're going to the superior and inferior teeth.
51. Save the work.