By: Najeebullah Department: Oral Anatomy

Origin of Periodontal Cells

& Differentiation of Cementoblasts

Tooth GermEnamel organ (ectodermal component)

Dental papillaDental sac or dental follicle

Ectomesenchymal component

Enamel organ

• Enamel

Dental papilla

• dentin• pulp

Dental follicle

• Cementum• PDL• Alveolar

bone

Precursor cells for cementoblast and PDL reside in Dental Follicle.

Epithelial cells from HERS may undergo transformation into Cementoblast

Origin of PDL Cells and Cementoblasts

HERS: (Hertwig’s epithelial root sheath) Consists of inner & outer enamel epithelia.

Cells of PDL Synthetic

cells

Resorptive cells

Progenitor cells

Defensive cells

fibroblasts, osteoblasts and cementoblasts.

cementoclasts , osteoclasts and fibroclasts.Note that fibroblasts perform both synthetic and resorptive activities.undifferentiated mesenchymal cells

macrophage, lymphocytes and mast cells

Newly formed dentin may cause dental sac cells to differentiate into cementoblasts.

cementoblasts then disperse to cover the root dentin area laying down cementoid.

Initially formed cementum in coronal two-thirds of the root is acellular.

when the cementoblasts get trapped in lacunae in their own matrix like bone cells, the cementum is called cellular or secondary cementum.

Differentiation of Cementoblasts