Facial Bones Flashcards
How many facial bones do we have?
14
How many paired facial bones do we have?
6
How many unpaired facial bones do we have?
2
What are the 6 paired facial bones called?
Inferior nasal conchae
Nasal bones
Maxillae
Palatine bones
Lacrimal bones
Zygomatic bones
What are the 2 unpaired facial bones called?
Mandible
Vomer
What are the main functions of the facial bones?
(4)
Characterising the shape of the human face
Protection for delicate organs, e.g. tonsils, throat, etc
Attachment for facial muscles
Passageway for the neurovascular structures
What does the fusion of the left and right maxillae at the midline form?
The upper jaw
What are the features of the maxillae?
(3)
It’s the central, paired bone within the viscerocranium
The fusion of the left and right maxillae at the midline forms the upper jaw
The intermaxillary suture is situated between the 2 maxillae
What are the components of the maxilla?
(5)
The body
The zygomatic process (zygomatic arch)
The frontal process
The alveolar process (teeth socket)
The palatine process (hard palate) (roof of mouth)
What is the primary function of the maxillae?
To support and secure the upper teeth in position
What do the zygomatic bones connect to?
The temporal bones
Which facial bone is this?
The maxillae
What are the features of the zygomatic bones?
(5)
They’re irregular paired bones located at the upper lateral part of the face
They’re referred to as cheek bones
They consist of 3 processes- frontal, maxillary and temporal processes
They articulate with the frontal bone, temporal bone, sphenoid bone and maxilla
They form the zygomatic arch
Which facial bone is this?
Zygomatic bone
What are the primary functions of the zygomatic bones?
(2)
Protects the eyes from direct blows
Provides attachment for masticatory muscles
What are the features of the lacrimal bones?
(3)
It’s the smallest and most delicate facial bone
It’s positioned in the anterior part of the medial wall of the orbit
It has 2 surfaces (lateral and medial) and 4 borders (anterior, posterior, superior and inferior)
What are the main functions of the lacrimal bones?
(3)
Provides support for the lacrimal apparatus structures
It’s responsible for tear secretion and drainage
It provides an attachment site for the orbicularis oculi muscle
Which facial bone is this?
Lacrimal bone
What are the features of the inferior nasal conchae?
(2)
Longest and broadest among the 3 conchae
Distinct from the superior and middle nasal conchae
What are the other 2 conchae made of?
Cartilage
What is the inferior nasal conchae made of?
Bone
What are the functions of the inferior nasal conchae?
(2)
It contributes to the formation of the middle and inferior nasal meatus, which directs the majority of airflow
It participates in humidifcation, heating and filtering of the air inhaled through the nose
What part of the face is this?
Inferior nasal conchae
What are the features of the palatine bones?
(3)
They’re L-shaped bones located posterior to the nasal cavity
They’re interposed between the maxilla and sphenoid bones
It’s defined by its horizontal and perpendicular plates
What are the main functions of palatine bones?
(3)
It participates in the formation of the horizontal plate
It participates in the formation of the perpendicular plate
It contributes to a small portion of the orbital floor
What does the horizontal plate do?
It forms the posterior portion of the hard palate of the oral cavity
What does the perpendicular plate do?
It contributes to the lateral wall of the nasal cavity
What are the features of the nasal bones?
(3)
It’s a paired, rectangle-shaped bones located posterior
The connection between the left and right nasal bones occur at the midline through the internasal suture
It establishes various connections with surrounding bones
What are the primary functions of the nasal bones?
(3)
To shape the bridge of the nose
They contribute to the formation of the nasal aperture
They provide protection to the nasal cavity against external factors
What are the features of the mandible?
(4)
It forms the lower jaw
It’s the largest facial bone, situated in the inferior portion of the face
It’s not part of the skull but is connected to it through the TMJ
It’s the only mobile bone in the head
How many ramus do we have?
2
What are the primary functions of the mandible?
(3)
To shape to contours of the face, including the chin and jawline
To support the lower teeth
With the TMJ, the mandible gains the ability to move in multiple directions, facilitating speech and chewing
What are the features of the vomer?
(2)
It’s situated in the midsagittal line
It’s a flat plate of bone situated vertically in the nasal cavity
What is the most complex joint in the body?
Temperomandibular joint (TMJ)
What type of joint is TMJ?
A hinge and ellispoid joint
What does TMJ stand for?
Temperomandibular joint
Where is the TMJ situated on the face?
Lateral aspect
What 3 surfaces does the TMJ articulate with?
(3)
Mandibular fossa
Articular tubercle
Head of the mandible
What are the functions of the TMJ?
(5)
Protrusion
Retraction
Elevation
Depression
Lateral
… movements of the mandible
What are movements of the mandible driven by in the TMJ?
4 muscles of mastication and hyoid muscles
What are the muscles of mastication?
(4)
Masseter
Temporalis
Medial pterygoid
Lateral pterygoid
What are the features of the masseter muscle?
(2)
It’s quadrangular in shape, with deep and superficial parts
It’s recognised as the most powerful muscle for mastication
Which muscle is recognised as the most powerful muscle for mastication?
The masseter
What is the feature of the temporalis muscle?
It originates from the temporal fossa
What are the features of the medial pterygoid muscle?
(2)
It’s quadrangular, with deep and superficial heads
It’s positioned inferiority to the lateral pterygoid
What are the features of the lateral pterygoid muscle?
(2)
It’s triangular in shape with superior and inferior heads
It’s the major protractor of the mandible
Which muscle of mastication is this?
Masseter muscle
Which muscle of mastication is this?
Temporalis muscle
Which muscles of mastication are these?
What 2 parts does the tooth consist of?
Crown
Root
What do the upper teeth connect to?
The maxilla
What do the lower teeth connect to?
The mandible
Label the tooth:
What is the end of the root of the tooth called?
The apex
Where is the apical foramen located?
At the apex of the tooth
What does the apical foramen do?
(2)
It allows blood vessels and nerves into the dental pulp
It’s a potential pathway for pulp infection
Which parts of the tooth do we tend to have issues with?
(4)
Enamel
Dentine
Dental pulp/pulp cavity
Cementum
What does the enamel of the tooth do?
(2)
Provides thermal insulation
Protects vital tissues but is susceptible to dental issues
What does the dentine of the tooth do?
It forms most hard tooth structure
What does the dental pulp/pulp cavity do?
It contains vessels and nerves
What does the dental pulp/pulp cavity do?
It contains vessels and nerves
Label the tooth:
Label the tooth:
What does human dentition mean?
The arrangement and/or condition of teeth in humans
What is the human dentition?
(4)
There’s 2 sets of teeth
There’s upper (maxillary) arches and lower (mandibular) arches
The arches are divided into left and right quadrants along the mid-sagittal plane
The teeth are situated in alveolar sockets, and are connected to the bone by a suspension periodontal ligament (gomphosis)
What are the 2 types of human dentition?
Primary dentition
Permanent dentition
Label the primary dentition:
Label the permanent dentition:
What type of tooth is this?
Left upper permanent tooth- central incisors
What type of tooth is this?
Left upper permanent tooth- lateral incisors
What type of tooth is this?
Left lower permanent tooth- central incisors
What type of tooth is this?
Left lower permanent tooth- lateral incisors
What type of tooth is this?
Left upper permanent tooth- canines (cuspids)
What type of tooth is this?
Left lower permanent tooth- canines (cuspids)
What type of teeth are these?
Left upper permanent teeth- premolars
What type of teeth are these?
Left lower permanent teeth- premolars
What type of teeth are these?
Left upper permanent teeth- molars
What type of teeth are these?
Left lower permanent teeth- molars
Label the upper permanent teeth:
Label the lower permanent teeth:
When does the upper central incisor erupt (primary dentition)?
8-10months
What are the features of primary dentition?
(3)
It’s composed of 20 teeth, 10 in each arch
There’s 5 teeth in each quadrant
Eruption begins at 6 months of age
What are the 5 teeth in each quadrant during primary dentition called?
Central incisor
Lateral incisor
Canine
1st molar
2nd molar
When does the upper lateral incisor erupt (primary dentition)?
8-10 months
When does the upper canine (cuspid) erupt (primary dentition)?
16-20 months
When does the upper 1st molar erupt (primary dentition)?
15-21 months
When does the upper 2nd molar erupt (primary dentition)?
20-24 months
When does the lower 2nd molar erupt (primary dentition)?
20-24 months
When does the lower 1st molar erupt (primary dentition)?
15-21 months
When does the lower canine (cuspid) erupt (primary dentition)?
16-20 months
When does the lower lateral incisor erupt (primary dentition)?
15-21 months
When does the lower central incisor erupt (primary dentition)?
6-9months
What are the features of permanent dentition?
(4)
It’s composed of 32 teeth, 16 in each arch
There’s 8 teeth in each quadrant
Eruption starts at 6 years of age
The complete eruption of teeth occurs at around 13 years old, except for the wisdom teeth, which usually erupt by 21 years old
What are the 8 teeth that are in each quadrant in permanent dentition?
Central incisor
Lateral incisor
Canine
1st premolar
2nd premolar
1st molar
2nd molar
3rd molar/wisdom teeth
Label the teeth from permanent dentition:
When does the upper central incisor erupt (permanent dentition)?
7th year
When does the upper lateral incisor erupt (permanent dentition)?
8th year
When does the upper canine (cuspid) erupt (permanent dentition)?
11th-12th year
When does the upper 1st premolar erupt (permanent dentition)?
9th year
When does the upper 2nd premolar erupt (permanent dentition)?
10th year
When does the upper 1st molar erupt (permanent dentition)?
6th year
When does the upper 2nd molar erupt (permanent dentition)?
12th-13th year
When do the 3rd molars/wisdom teeth erupt (permanent dentition)?
17th-25th year
When do the lower 2nd molar erupt (permanent dentition)?
12th-13th year
When does the lower 1st molar erupt (permanent dentition)?
6th year
When does the lower 2nd premolar erupt (permanent dentition)?
10th year
When does the lower 1st premolar erupt (permanent dentition)?
9th year
When does the lower canine (cuspid) erupt (permanent dentition)?
11th-12th year
When does the lower lateral incisior erupt (permanent dentition)?
8th year
When does the lower central incisor erupt (permanent dentition)?
7th year
What are the dental functions?
(3)
Mastication- chewing, breaking down foods, nutrition
Speech- enabling us to pronounce words
Shaping the face- plays an important role in one’s smile, self confidence and facial aesthetics
What are the features of the incisors?
(6)
Primary and permanent dentition have 4 uppers and 4 lowers
They’re closest to the midline (anterior region)
They have straight edges designed for incising food
They’re positioned at the front of the mouth
They’re important for function and aesthetics
They’re more prone to trauma injuries
What are the features of the canines?
(5)
Primary and permanent dentition have 2 uppers and 2 lowers
They’re positioned at the corners of the mouth
They have sharp, triangular incisal edges for piercing and holding food
They have long, stable roots that are capable of withstanding more than incisors
They commonly have insufficient space to erupt
What are the features of premolars?
(4)
They’re only found in permanent dentition
There’s 4 uppers and 4 lowers
They’re positioned between Cannes and molars
Sometimes dentists extract premolars to relieve severe dental crowding before orthodontic treatment (braces)
What are the features of molars?
(5)
Primary dentition has 4 uppers and 4 lowers
Permanent dentition has 6 upper and 6 lowers
They’re located at the posterior region
They’re designed for crushing and chewing food before swallowing
Molars are prone to dental caries due to deep grooves on the surface and wider points of contact
