Figure 4: An overview of the root-close periodontal membrane in different conditions or diseases affecting the ectoderm (ecto), mesoderm (meso), and neuroectoderm (neuro). The root-close tissue layers are explained in Figure 1 and marked in figure (a). (b) Illustrates that general changes in the ectoderm (e.g., ectodermal dysplasia) affect the root-close tissue layer, which hypothetically appear as thin red lines. (c) Illustrates that general changes in the mesoderm or ectomesenchymal (e.g., osteogenesis imperfect) affect the root-close tissue layer illustrated by sparse green lines. (d) Illustrates that general changes in the neuroectoderm (e.g. meningitis spreading to peripheral nerves) affect the root-close tissue layer which appear with very few yellow dots