Lecture 5 - Normal Anatomy Flashcards
Enamel
Most radiopaque
Densest substance in body
90% mineralized
Dentin
75% mineralized
Meets with enamel at DEJ
Pulp
Soft tissue from interior of crown to apex of roots
Radiolucent
Pulp chamber decreases with age due to secondary dentin deposition (apex to crown)
Secondary dentin deposition
Age Acute trauma Caries Erosion Attrition
Cementum
50% mineralized
Thin layer, mainly on root surface
Meets with enamel at CEJ
Can’t be seen on radiograph, same density as dentin
Cause of divergent roots
1) Tooth and roots still developing - in a mature tooth, the pulp walls in apical region constrict
2) Trauma such as bruxism
Dental papilla
Forms dentin and primordial pulp
Cervical burnout
Normal
Radiolucent area b/t enamel and crest of alveolar ridge
Lamina dura
Thin, radiopaque, well-defined layer of dense bone that surrounds the tooth socket
Continuous with cortical bone at alveolar crest
Thicker/denser with greater occlusal stress
Intact lamina dura usually indicates vital pulp
Alveolar crest
Radiopaque line represents gingival margin of alveolar process b/t teeth
Continuous and forms sharp angle with lamina dura
Shorter in anterior teeth than posterior
Recedes with age & periodontal disease
Periodontal ligament
Composed of collagen
Radiolucent space b/t root and lamina dura
Extends whole tooth from alveolar crests
Thinner at root apex, wider at alveolar crest
Intermaxillary suture
Thin, radiolucent line in midline of maxilla
B/t central incisors superior to anterior nasal spine and posterior b/t palatine processes to the posterior aspect of the hard palate
Bordered by radiopaque thin cortical bone lines
Anterior nasal spine
Radiopaque at junction of the inferior end of nasal septum, between maxillary central incisors
1.5-2 cm above alveolar crest
Nasal fossa
Air-filled
Radiolucent
Inferior border is radiopaque lines extending bilaterally from base of anterior nasal spine
Incisive/nasopalatine foramen
Oral terminus of nasopalatine canal
Vessels and nerves to max. central incisors
Radiolucent b/t roots and middle-apical 1/3 of central incisors
Superior foramina of nasopalatine canal
Origin of nasopalatine canal in floor of nasal cavity
Travel on either side of nasal septum and unite at foramen
Lateral fossa
Depression in maxilla near apex of lateral incisor
Diffusely radiolucent on periapical
Not pathologic if lamina dura is intact
Nasolacrimal canal
Drains under the inferior concha of nasal cavity
Above apex of canine on periapical
