TCDHA Orofacial Structures Semester 1 Final
Exam Study Guide (2024–2025 Edition) Complete
Review of Head & Neck Anatomy for Dental
Hygiene Students – Bones, Muscles, Cranial
Nerves, TMJ, Salivary Glands, Vasculature,
Lymphatics, Landmarks, and Histology
The tendency of the permanent molars to have an eruptive force toward the
midline (erupt occlusally and forced mesially)
Mesial drift
The process by which the roots of a baby tooth are resorbed and dissolved until
so little root remains that the baby tooth falls out
Exfoliation
As the permanent tooth erupts, osteoclastic cells destroy the root of the
deciduous tooth which is called:
Resorption
Bone-destroying cells that destroy the roots of the deciduous teeth
Osteoclasts
The pressure applied by the eruption of the permanent tooth on the deciduous
root triggers the body to activate:
Osteoclasts
The wearing away of the tooth through contact of its functioning surfaces
Attrition
,True or False
Eruptive forces do not cease after the eruption of the 3rd molars
True
Eruption continues because of:
Attrition
Occlusal plane
Formed when teeth erupt and meet their opposing tooth
The curved alignment of the occlusal plane
Curve of Spee
Proximal Contact Areas
2 adjacent teeth share the same proximal bone - the bone that supports the distal
root portion of the first tooth also supports the mesial portion of the second tooth
What does a contact area do?
- prevents food impaction and bacteria invasion
- protects underlying gum tissue between teeth
- provides support and anchorage for the teeth
- helps resist displacement from trauma
Where the occlusal cusp/incisal edge of the tooth touches the occlusal/incisal
portion of another tooth in the opposing arch
Contact point
Triangular shaped spaces between the teeth
Interproximal spaces (also called interdental spaces)
When gingival recession occurs between the teeth, the interdental papilla and
bone no longer fill the entire interproximal space; a void exists cervically to the
contact area
Cervical embrasure
, Mandibular molars are situated more mesially than their maxillary counterparts
Mesial step
Distal surfaces of deciduous 2nd molars are even with each other
Flush terminal plane
Mandibular molars are more posterior than maxillary molars
Distal step
Primate Spaces
Large spaces found mesial to the maxillary canines and distal to the mandibular
canine
Overjet
The amount (measured in mm) of facial horizontal overlap of the maxillary teeth
Overbite
The extension of the incisal edges of the maxillary anterior teeth below the incisal
edges of the mandibular anterior teeth in a vertical direction - amount of vertical
overlap measured in mm or percentage
Ridge
-Elevated portion that runs in a line
-Named for their location
-All cusps have 4 ridges: buccal, lingual, mesial. distal
Marginal ridges
Rounded borders of enamel that form the mesial and distal shoulders of the
occlusal surfaces of posterior teeth and the mesial and distal shoulders of the
lingual surface of anterior teeth
The general arrangement of the teeth
Dentition
Exam Study Guide (2024–2025 Edition) Complete
Review of Head & Neck Anatomy for Dental
Hygiene Students – Bones, Muscles, Cranial
Nerves, TMJ, Salivary Glands, Vasculature,
Lymphatics, Landmarks, and Histology
The tendency of the permanent molars to have an eruptive force toward the
midline (erupt occlusally and forced mesially)
Mesial drift
The process by which the roots of a baby tooth are resorbed and dissolved until
so little root remains that the baby tooth falls out
Exfoliation
As the permanent tooth erupts, osteoclastic cells destroy the root of the
deciduous tooth which is called:
Resorption
Bone-destroying cells that destroy the roots of the deciduous teeth
Osteoclasts
The pressure applied by the eruption of the permanent tooth on the deciduous
root triggers the body to activate:
Osteoclasts
The wearing away of the tooth through contact of its functioning surfaces
Attrition
,True or False
Eruptive forces do not cease after the eruption of the 3rd molars
True
Eruption continues because of:
Attrition
Occlusal plane
Formed when teeth erupt and meet their opposing tooth
The curved alignment of the occlusal plane
Curve of Spee
Proximal Contact Areas
2 adjacent teeth share the same proximal bone - the bone that supports the distal
root portion of the first tooth also supports the mesial portion of the second tooth
What does a contact area do?
- prevents food impaction and bacteria invasion
- protects underlying gum tissue between teeth
- provides support and anchorage for the teeth
- helps resist displacement from trauma
Where the occlusal cusp/incisal edge of the tooth touches the occlusal/incisal
portion of another tooth in the opposing arch
Contact point
Triangular shaped spaces between the teeth
Interproximal spaces (also called interdental spaces)
When gingival recession occurs between the teeth, the interdental papilla and
bone no longer fill the entire interproximal space; a void exists cervically to the
contact area
Cervical embrasure
, Mandibular molars are situated more mesially than their maxillary counterparts
Mesial step
Distal surfaces of deciduous 2nd molars are even with each other
Flush terminal plane
Mandibular molars are more posterior than maxillary molars
Distal step
Primate Spaces
Large spaces found mesial to the maxillary canines and distal to the mandibular
canine
Overjet
The amount (measured in mm) of facial horizontal overlap of the maxillary teeth
Overbite
The extension of the incisal edges of the maxillary anterior teeth below the incisal
edges of the mandibular anterior teeth in a vertical direction - amount of vertical
overlap measured in mm or percentage
Ridge
-Elevated portion that runs in a line
-Named for their location
-All cusps have 4 ridges: buccal, lingual, mesial. distal
Marginal ridges
Rounded borders of enamel that form the mesial and distal shoulders of the
occlusal surfaces of posterior teeth and the mesial and distal shoulders of the
lingual surface of anterior teeth
The general arrangement of the teeth
Dentition
