1009DOH / 1019DOH / 1040DOH
Oral Biology 2 / Applied Oral Biology 2 /
Clinical Dental Practice 1
Laboratory Manual
Anatomy of the Head and Neck Region
Laboratory 1
Embryology
Learning objectives:
1- Describe the embryology of the face
2- Describe the derivatives of pharyngeal arches
Embryology of the face and pharyngeal arches
(Textbook of Head &Neck Anatomy, 4th Edition, Wolters Kluwer Lippincott Williams &
Wilkins Philadelphia, PA, USA Chapter 5;).
Pharyngeal arch embryology:
Pharyngeal Arches are blocks or bars of condensed mesenchymal tissue that are located
between the pharyngeal pouches and pharyngeal clefts (or grooves). Each arch is numbered
in order of their location (reflecting developmental sequence), arch 1 (Mandibular), 1
(Hyoid), arch 3, arch 4 and arch 6. Arch 5 doesn’t develop in humans and although
rudimentary arch 6 contributes with arch 4 to form thyroid and laryngeal cartilages and other
muscular and neural structures.
View timepoints 1:45 minutes to 5:30 minutes of the following video to review your
understanding of pharyngeal arch development
Why is learning about pharyngeal arch development of assistance for your future clinical
practice?
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Before or after your laboratory class, review Table 5.1 page 55, Chapter 5, Hiatt
J.L.and Gartner L.P. Textbook of Head &Neck Anatomy, 4th Edition, Wolters Kluwer
Lippincott Williams & Wilkins Philadelphia, PA, USA Chapter 5 which describes
Pharyngeal arch derivatives and their innervation.
Complete your own table to summarise key information from your lectures on the pharyngeal
arches and their derivatives (see sheet at end of these laboratory notes).
Pharyngeal Arch 1 and embryology of the face
View timepoints 5:30 minutes to 12:30 minutes of the following video to review your
understanding of facial embryology http://www.youtube.com/watch?v=SG3do_BeB0M
Now view this short summary animation which demonstrates the growth and fusion of the
regions of the frontonasal prominence and Pharyngeal Arch 1 prominences.
Please note the colours in the video represent the following:
Frontonasal Prominence central portion (white)
Frontonasal Prominence - Lateral nasal (purple)
Frontonasal Prominence - Medial nasal (green)
Pharyngeal Arch 1 - Maxillary prominence (yellow)
Pharyngeal Arch 1 - Mandibular prominence (orange)
http://php.med.unsw.edu.au/embryology/images/d/d7/Face_001.mov
These lecture and practical notes from the University of NSW will assist your study so work
your way through them.
http://php.med.unsw.edu.au/embryology/index.php?title=BGD_Lecture__Face_and_Ear_Development
http://php.med.unsw.edu.au/embryology/index.php?title=BGDB_Practical__Face_and_Ear_Development
Sutures, sinuses and foetal skulls
In adults, the cranial bones are united by fibrous joints which are synarthrotic as they do not
permit movement. Note the joints between the skull bones.
Locate and examine these cranial sutures:
Sagittal suture: Which bones does it connect?
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Coronal suture: Which bones does it connect?
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Lambdoid suture: Which bones does it connect?
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Squamous suture: Which bones does it connect?
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What type of tissue is found in these joints?
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What may happen to these joints as adults age?
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The Pterion is a landmark feature of the skull, where the skull thickness is minimal.
Which four bones connect here?
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2._________________________________________________________________________
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3._________________________________________________________________________
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4._________________________________________________________________________
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Paranasal Sinuses:
Clustered around the nose are mucosa-lined, air filled sinuses which are located in 5 bones of
the skull (Ethmoid, Sphenoid, Frontal and each of the pair of maxillary bones).
Identify two general functions of sinuses
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2._________________________________________________________________________
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Where do sinus drain?
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Using the x-rays and the skulls, identify the air sinuses in the skull.
Frontal
Maxillary: NOTE the proximity of the upper molar teeth to this sinus
Ethmoid
Sphenoid
From you observations of the location of these sinuses, briefly explain may infections spread
to these paranasal sinuses.
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During extraction of upper molar and premolar teeth, an oroantral communication may occur.
What do you think is meant by the term oroantral communication
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The mastoid process of the temporal bone also contains air cells connected to atmosphere via
the tympanic cavity and pharyngotympanic (Eustachian) tube. What is the clinical relevance
of these air cells?
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Foetal skull: Identify the following structures on the foetal skull model
Locate the Anterior fontanelle, posterior fontanelle and mastoid (posterolateral) fontanelle
and label them on the diagrams below.
In the lateral view, note the relative
size of the cranial vault compared to
the size of the face. The mandible is
particularly underdeveloped and the
acoustic meatus is very shallow. See
Figures 1.3 and 1.4 page 3, Head and
Neck Anatomy for Dental Medicine
(2010) Eric W. Baker Editor Thieme
Medical Publishers Inc NY USA
Or Figure 7.39a 244 Chapter 7 Marieb
& Hoehn, Human Anatomy and
Physiology, 2013, 9th Edition Pearson
Education for foetal adult comparisons
Figure 7.36ab, page 244 Chapter 7 Marieb & Hoehn, Human Anatomy and Physiology, 2013, 9 th Edition
Pearson Education
Now locate and name the sutures you identified in the adult skull.
What difference do you notice between the sutures of the foetal and adult skulls?
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What type of tissue covers the fontanelles in infants? What type of ossification occurs here?
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