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Mandible & maxilla

General

Anatomy & histology

Author: Nat Pernick, M.D.

Last author update: 1 October 2013

Last staff update: 28 August 2020

Copyright: 2004-2024, PathologyOutlines.com, Inc.

PubMed Search: Mandible maxilla histology[title]

Table of Contents

Cite this page: Pernick N. Anatomy & histology. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/mandiblemaxillahistology.html. Accessed December 25th, 2024.

Anatomy

Contain primitive embryonic structures from early fetal development to 25 years of age
Divided into alveolar bone (supports teeth) and body with variable thickness ranging from paper thin overlying roots of cuspid (canines) and bicuspid (premolar) teeth to thick at apex of chin
Mandible
- Receptor for lower teeth
- Consists of curved horizontal body and two perpendicular rami
Maxillae
- Forms upper jaw, boundaries of roof of mouth, floor and lateral wall of nose, floor of orbit
- Consists of zygomatic, frontal, alveolar and palatine processes

Development

Primitive oral cavity (dental lamina, derived from ectoderm) invaginates, acquires a bell shape, and ameloblasts develop along inner (concave) surface; called "enamel organ" at this stage
Dental papilla, derived from mesoderm, forms within "enamel organ", is loose stellate reticulum; its outer layer matures to become odontoblasts
Dental sac or follicle forms from outer layer of dental papillae / odontoblasts, which form periodontium, a fibrous sheath enveloping the tooth
Inner layer of dental sac becomes cementoblasts and deposit cement over newly formed dentin, and outer layer of dental sac becomes osteoblasts and produces alveolar bone

Three phases of activity

Initiation of entire deciduous dentition (first set of teeth) during second month of gestation (above)
Initiation of permanent dentition (second set of teeth) and extension of dental lamina distal to dental organ of second deciduous molar
After 5 - 6 years of activity, dental lamina breaks up into epithelial rests or islands that may develop into odontogenic cysts or tumors

Teeth

From medial to lateral:
- Incisors
- Canines (cuspids)
- Premolars (bicuspids)
- Molars

Ameloblasts

Also called adamantoblasts
Secrete enamel matrix

Cementicles

Rounded, strongly basophilic structures normally within periodontal ligament

Cementum

Similar to bone, cellular or acellular, intensely basophilic
Also present in other parts of skeletal system

Dental lamina

Epithelium with potential to develop teeth
Derived from primitive oral epithelium along free margin of arches of jaws

Dental pulp

Hypocellular, myxoid
Resembles myxoma but is compact and has peripheral odontoblasts

Dentin

Radially striated due to numerous minute canals (dentinal tubules) containing cytoplasmic processes from odontoblasts
Resembles osteoid if tubules / canals are absent

Enamel