BGDB Face and Ear - Postnatal

Postnatal Skull

Skull CT Vertex, later and basal views.

rapid brain growth in the early years of life (growth of the neurocranium stopping at about 7 years of age). fontanels usually close by the second year of life posterior fontanel by about 3 months. anterior fontanel by about 20 months. Complete sutural fusion occurs after the third decade of life. Sutures and Fontanels a - Metopic suture b - coronal sutures c - sagittal suture d - lambdoid suture e - squamosal suture f - anterior fontanel g - posterior fontanel h - sphenoidal fontanel i - mastoid fontanel Adult Skull MRI Links: Skull Development - MRI  ‎‎Viscerocranium Page | Play  ‎‎Temporal Bones Page | Play  ‎‎Occipital - Frontal Page | Play  ‎‎Parietal-Zygomatic Page | Play

Head Growth

Head growth and corresponding charts differ slightly for girls and boys. Given as head circumference-for-age Birth to: 13 weeks, 2 years, 5 years.

Girls	Boys
Chart PDF | WHO - Girls	Chart PDF | WHO - Boys

Links: Growth Charts | Neural Exam Movies | - Standard Head circumference-for-age | WHO Growth Standards

Adult Palate

The Palate (palatum) forms the roof of the mouth; it consists of two portions, the hard palate in front, the soft palate behind. Hard Palate (palatum durum) is bounded in front and at the sides by the alveolar arches and gums; behind, it is continuous with the soft palate. It is covered by a dense structure, formed by the periosteum and mucous membrane of the mouth, which are intimately adherent. Along the middle line is a linear raphæ, which ends anteriorly in a small papilla corresponding with the incisive canal. On either side and in front of the raphé the mucous membrane is thick, pale in color, and corrugated; behind, it is thin, smooth, and of a deeper color; it is covered with stratified squamous epithelium, and furnished with numerous palatal glands, which lie between the mucous membrane and the surface of the bone. Soft Palate (palatum molle) is a movable fold, suspended from the posterior border of the hard palate, and forming an incomplete septum between the mouth and pharynx. It consists of a fold of mucous membrane enclosing muscular fibers, an aponeurosis, vessels, nerves, adenoid tissue, and mucous glands. When occupying its usual position, i. e., relaxed and pendent, its anterior surface is concave, continuous with the roof of the mouth, and marked by a median raphé. Its posterior surface is convex, and continuous with the mucous membrane covering the floor of the nasal cavities. Its upper border is attached to the posterior margin of the hard palate, and its sides are blended with the pharynx. Its lower border is free. Palatine velum lower portion, which hangs like a curtain between the mouth and pharynx. Palatine Uvula hangs from the middle of its lower border and is a small, conical, pendulous process. Arches of the fauces (pillars of the fauces) lateralward and downward from the base of the uvula on either side are two curved folds of mucous membrane, containing muscular fibers.

Postnatal Ear

First, look through the adult ear structures and identify their developmental origins.

Auditory Tube (Eustachian, otopharyngeal or pharyngotympanic tube) Connects middle ear cavity to nasopharynx portion of pharynx. Tube is normally closed and opened by muscles. Ventilation - pressure equalization in the middle ear Clearance - allow fluid drainage from the middle ear Newborn to adult auditory tube Birth shorter (17-18 mm), narrower and runs almost horizontal Tube is opened by a single muscle, tensor palati muscle Adult longer (twice as long), wider and runs at approximately 45 degrees to the horizontal. Tube is opened by two separate muscles, tensor palati and levator palati

Hearing Testing

Newborn hearing test

Abnormalities in neonatal hearing can impact upon development of the nervous system and developmental learning milestones, early detection is therefore key.

The incidence of significant permanent hearing loss is approximately 1-3/1000 newborns. Neonatal hearing screening is carried out in several countries including the USA, UK and in Australia. In NSW the Statewide Infant Screening Hearing (SWISH) Program was introduced in 2002.

There is also a general guide giving a timetable for a number of simple responses that a neonate should make if hearing has developed normally (More? Neonatal Hearing Check List).

The two major forms of hearing loss are conductive and sensorineural.

State Wide Infant Screening Hearing Program (SWISH) a newborn hearing testing program using an automated auditory response technology (AABR). Program was introduced in NSW Australia in 2002 across 17 area health service coordinators. It is thought that in NSW 86,000 births/year = 86-172 babies potentially born with significant permanent hearing loss.

Automated Auditory Brainstem Response (AABR) uses a stimulus which is delivered through earphones and detected by scalp electrodes. The test takes between 8 to 20 minutes and has a sensitivity 96-99%.

Links: Hearing test

Additional Information

Additional Information - Content shown under this heading is not part of the material covered in this class. It is provided for those students who would like to know about some concepts or current research in topics related to the current class page.

Head Measurements

Normal Head	Abnormal Head
‎‎ Head Shape Page | Play	‎‎Head Shape Page | Play
‎‎Head Circumference Page | Play	‎‎Head Circumference Page | Play

Links: Growth Charts | Neural Exam Movies | - Standard Head circumference-for-age | WHO Growth Standards

External Auditory Meatus Changes

Birth	Adult

Neonatal Hearing Check List

The timing and types of responses listed below reflect only a rough guide for the general population. Abnormalities in neurological, visual or motor skill development can also affect responses.

• Birth to 3 months - Reacts to loud sounds, Quiets to familiar voices or sounds, Makes cooing noises, Responds to speech by looking at speaker’s face.
• 3 to 6 months - Turns eyes or head toward sounds, Starts to make speech-like sounds, Laughs and makes noises to indicate pleasure and displeasure.
• 6 to 9 months - Babbles, ‘dada’‘ma-ma’‘baba’, Shouts/vocalises to get attention, Will often respond to ‘no’ and own name, Responds to singing and music.
• 9 to 12 months - Imitates speech sounds of others, Understands simple words, eg ‘ball’,‘dog’, ‘daddy’, Turns head to soft sounds, First words emerge.
• 12 to 18 months _ Appears to understand some new words each week, Follows simple spoken instructions, eg ‘get the ball’, Points to people, body parts or toys when asked, Continually learns new words to say although may be unclear.
• 18 to 24 months - Listens to simple stories or songs, Combines two or more words in short phrases eg ‘more juice’.

Hearing check list text based upon NSW Health Pamphlet - Why does my baby need a hearing check?

Neural Exam

The following are examples of simple neural assessment of development in early hearing and understanding.

12 month Behaviour	18 month Behaviour	30 month Behaviour
<html5media height="290" width="320">File:12mo 02.mp4</html5media>	<html5media height="290" width="320">File:18mo 02.mp4</html5media>	<html5media height="290" width="320">File:30mo 02.mp4</html5media>

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Cite this page: Hill, M.A. (2024, April 19) Embryology BGDB Face and Ear - Postnatal. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/BGDB_Face_and_Ear_-_Postnatal

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G