Articles
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1,950 results found
Article
Aicardi syndrome
Aicardi syndrome is a rare severe developmental disorder. It results from an X-linked genetic defect that is fatal in males and therefore only manifests in females (except for rare 47, XXY cases).
Terminology
Aicardi syndrome is distinct from Aicardi-Goutieres syndrome although both are named ...
Article
Nasal dermoid cyst
Nasal dermoids (or nasal dermoid sinus cysts) are the most common congenital midline nasal lesion typically presenting in early childhood.
Epidemiology
Nasal dermoids are rare and account for only 4-12% of all dermoid cysts of the head and neck, far less common than angular dermoids 1,2. They ...
Article
Frontal intersinus septal cells
Frontal intersinus septal cells, also known as interfrontal sinus septal cells, are a subtype of medial frontal recess cells.
Gross anatomy
The frontal intersinus septal cells lie within the intersinus septum between the frontal sinuses. They usually drain in the medial aspect of the frontal r...
Article
Retromolar trigone
The retromolar trigone, sometimes called the retromolar fossa, is an oral cavity subsite that consists of the mucosa posterior to the last mandibular molar. It is roughly triangular shaped and extends superiorly towards the maxilla along the anterior surface of the mandible.
Gross anatomy
Att...
Article
Kayser-Fleischer rings
Kayser-Fleischer rings, sometimes shortened to K-F rings, are caused by copper deposition in the cornea and are a specific, clinical sign of Wilson disease.
Clinical presentation
They are usually brown or dark reddish in color. Early on they may need a slit lamp to be visible before they becom...
Article
Deep spaces of the head and neck
The deep spaces of the head and neck refer to compartments delimited by the deep cervical fascia. While these concepts overlap with traditional anatomical descriptions, their existence highlights the importance of fascia in confining various pathologies.
A knowledge of these spaces not only all...
Article
Primary acquired nasolacrimal duct obstruction (PANDO)
Primary acquired nasolacrimal duct obstruction (PANDO) is a chronic inflammatory cause of nasolacrimal drainage apparatus obstruction.
Epidemiology
Most commonly seen in middle-aged or elderly women.
Pathology
Etiology
The exact cause is still not very well known however it thought to be...
Article
Endolymphatic duct
The endolymphatic duct is a small epithelial-lined channel, part of the membranous labyrinth that passes through the vestibular aqueduct in the bony labyrinth of the petrous temporal bone. It arises from the utricle and saccule via the utriculosaccule duct and drains endolymph. The distal end is...
Article
Rhinolith
Rhinoliths, also known as nasal calculi, are uncommon lesions that result from a chronic inflammatory response to complete or partial mineralized encrustation of intranasal foreign bodies. They are most commonly seen in children and cognitively impaired adults who insert foreign bodies into thei...
Article
Amaurosis fugax
Amaurosis fugax is the transient monocular loss of vision, normally lasting a few seconds to a few minutes, secondary to vascular ischemia or insufficiency.
Epidemiology
It has an incidence of 50,000 per year in the United States.
Clinical presentation
Patients present with transient monoc...
Article
Microgenia
Microgenia is a term meaning a small chin. It is somewhat related to but distinct from the term micrognathia which means a small mandible.
Pathology
Associations
Microgenia can be isolated or be associated with a number of anomalies which include
campomelic dysplasia 1
hydrolethalus
Noonan...
Article
Basal cell adenoma
Basal cell adenomas are uncommon salivary gland tumors, representing ~4% (range 1-7.5%) of benign parotid tumors. They can also occur in the other major salivary glands as well as the minor salivary glands.
Clinical presentation
Most commonly, a painless growing mass 1.
Pathology
Typically,...
Article
Blunt traumatic neck injury
Blunt traumatic neck injury is uncommon because it is usually protected by the head, shoulders, and chest. This term is generally used to refer to injuries of the neck besides to cervical spine injuries, which are common.
Pathology
Blunt injury to the neck is most commonly from motor vehicle ...
Article
Squamosal suture
The squamosal or squamous suture is the cranial suture between the temporal and parietal bones bilaterally. From the pterion, it extends posteriorly, curves inferiorly and continues as the parietotemporal suture.
Along with growth of the pterion, the asterion and at the frontozygomatic suture, ...
Article
Boogard's angle
Boogard's angle is measured by drawing a line from basion to opisthion and another line along the plane of the clivus to the basion intersecting the first line - the angle between these two lines is measured.
The normal angle is 126° +/- 6°. If the angle measures more than 136° it is indicative...
Article
Nasolacrimal drainage apparatus
The nasolacrimal (drainage) apparatus consists of:
lacrimal canaliculi
lacrimal sac
nasolacrimal duct
Gross anatomy
Tears produced by the lacrimal gland, accessory lacrimal glands of Krause, Wolfring and Zeis, and Meibomian glands track medially along the eyelid margins and collect at the l...
Article
Nasolacrimal canal
The nasolacrimal canal is the short bony passage along which the nasolacrimal duct courses in the face.
Gross anatomy
lateral wall
lacrimal groove of the medial maxilla
lacrimal hook of the lacrimal bone
medial wall
superiorly: lacrimal bone
inferiorly: lacrimal process of the inferior n...
Article
Medial wall of the orbit (mnemonic)
A useful mnemonic to remember the bones forming the medial wall of the orbit is:
My Little Eye Sits (in the orbit); or
Medial Layer Eye Socket
Mnemonic
M: maxilla (frontal process)
L: lacrimal
E: ethmoid (lamina papyracea)
S: sphenoid (body)
Article
Anderson and Montesano classification of occipital condyle fractures
The Anderson and Montesano classification is a widely used system for describing occipital condyle fractures. It divides injuries into three types based on morphology and mechanism of injury 1-5.
Classification
type I: impacted type occipital condyle fracture
morphology: comminution of the co...
Article
Orthopantomography
The orthopantomogram (also known as an orthopantomograph, pantomogram, OPG or OPT) is a panoramic single image radiograph of the mandible, maxilla and teeth. It is often encountered in dental practice and occasionally in the emergency department; providing a convenient, inexpensive and rapid way...
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