Anatomy of Teeth and Periodontal Tissues

Anatomy of Teeth and Periodontal Tissues

• Most vertebrates have teeth, simplest being conical and single-lobed (reptiles - homodont).
• Temporomandibular movements are linked to tooth morphology, often resulting in limited lateral movement.
• Mammals have 3-lobed teeth (heterodont dentition).
• Only mammals have multi-rooted teeth.
• Canine teeth lack significant lateral movement.
• The morphology of molar teeth in some mammals facilitates lateral jaw movement.
• The most complex teeth have 4-5 lobes.
• Anthropoid ape dentition is similar to human dentition, with relatively longer canines.
• Ungulates exhibit the greatest lateral jaw movement capacity.

Comparative Anatomy

• Most vertebrates have teeth, but simplest teeth are conical and single-lobed (reptiles - homodont).
• In mammals, simplest teeth are conical with one lobe.

Root Structure

• Teeth have various root numbers (single or multiple).
• Incisors, canines, and premolars often have a single root, while molars usually have two or three roots.
• Root numbers can differ between individuals.

Anatomy of the Periodontium

• The periodontal tissues support teeth, provide connection, protect against oral microbes, and allow proprioceptive sensing.
• The periodontium contains gingiva (facing the teeth), periodontal ligament (PDL), cementum, and alveolar bone.

Gingiva (Gums)

• Gingiva is part of the oral mucosa, composed of three zones.
• Masticatory mucosa (25%)
• Specialized mucosa covering the tongue (15%)
• Lining mucosa (60%)

Gingiva- Clinical Parts

• Marginal gingiva: bordering the tooth.
• Sulcus: the groove between the tooth and marginal gingiva.
• Attached gingiva: gingiva proper, firmly bound to the tooth.
• Interdental gingiva: between the teeth.

Epithelial Junction (Dentogingival Junction)

• It's the boundary between the oral cavity and underlying tissues.
• Located at the bottom of the gingival sulcus.
• Composed of 10-30 layers of non-keratinized stratified squamous epithelium.
• Consists of basal and suprabasal cells.

Cementum

• Covers the anatomical root.
• Acellular cementum: cementoblasts remain on the surface.
• Afibrillar
• Extrinsic fibers
• Cellular cementum: cementoblasts integrate into the matrix (lacunae). After mineralization, are called cementocytes.
• Intrinsic fibers

Development of Cementum

• Cementoblasts differentiate from the dental follicle.
• Epithelial cell rests (Malassez) may linger after complete development, influencing periodontal regeneration.

Sharpeys Fibers

• Primarily present in acellular extrinsic fiber cementum.
• Important for resilient attachment of the tooth.

Periodontal Ligament (PDL)

• PDL is a specialized connective tissue.
• It links the root and alveolar bone.
• Contains type I collagen fibers (Sharpey's fibers), helping to absorb masticatory forces.
• Contains cells for force distribution, shock absorption, and proprioception.
• Sharpeys fibers are arranged into bundles:
• Transseptal
• Interradicular
• Apical
• Oblique
• Horizontal
• Alveolar crest

Alveolar Bone

• Alveolar bone has basic histological structures similar to other bones but with distinctive layers.
• The layers are cortical compact bone, alveolar bone proper (lamina dura), and trabecular bone.

Explore the fascinating anatomy of teeth and periodontal tissues, focusing on their morphology and function in different vertebrates. This quiz delves into the differences between homodont and heterodont dentition, as well as the unique root structures and movements associated with these dental forms.