Surface Anatomy Flashcards
Nasion
Bony nasofrontal suture
Sellion
soft tissue overlying nasion
radix
root of the nose that encompasses the nasion and sellion
glabella
prominence of the frontal bone between the eyebrows and above the radix
upper lateral cartilage
triangular or trapezoidal in shape and fuse in midline to cartilaginous dorsum
keystone area
region where the ULCs attach to the undersurface of the nasal bone; may overlap by up to 11 mm
scroll
caudal ULC area where it articulates with the LLC
supratip
junction of nasal dorsum and nasal tip
infratip
junction of tip and columella
lower lateral cartilage
C-shaped
3 parts: medial crus, intermediate/middle crus, lateral crus
medial crura of the LLC
Narrowest segment of LLC
Consists of a footplate segment that flares posterolaterally and an anterior segment that defines the contour of the columella
Attached to caudal septum by fibrous tissue and separated from each other by loose connective tissue
intermediate crura of the LLC
Flare posterolaterally away from each other at the angle of divergence
Joins lateral crus at the dome
lateral crura of the LLC
Convex in shape
Extend posteriorly from the intermediate crura
Initially parallel the alar rim but then turn posteriorly, superiorly, and laterally toward pyriform aperture
Meets the ULC at the scroll regions
Angle of divergence
Where the intermediate crura flare posterolaterally away from each other
Contributes to infratip lobule
Normally 50-60 deg
If > 60 deg –> wide or boxy tip
Dome
Point where intermediate crus joins lateral crus
Highest and most anterior point of nasal tip
Joined medially by the interdomal ligaments
Modified surgically to refine nasal tip
Nose subunits
9
nasal dorsum, tip, columella, paired nasal sidewalls, ala/sills, and soft triangles
Ideal facial height divisions
Equally in thirds between trichion, glabella, subnasale, and menton
Ideal facial width divisions
Equally into fifths
Width of one eye = 1/5 = intercanthal distance
5 soft tissue components of nose deep to dermis
- superficial fatty panniculus
- fibromuscular layer
- deep fatty layer
- longitudinal fibrous sheet
- interdomal ligament
Fibromuscular layer of the nasal soft tissue
Consists of the nasal mimetic muscles
Encased and interconnected by the nasal SMAS
Elevation of nasal tissue should be in sub-SMAS plane
Tripod theory of nasal tip
3 limbs: 1 for conjoined medial crura and 2 lateral crura legs
Change in limb length results in predictable changes in nasal tip position
Decreasing all limbs equally –> tip deprojection
Increasing all equally –> inc projection
Shortening medial crura –> caudal tip rotation
Lengthening lateral crura –> caudal tip rotation
Opposite –> cephalic tip rotation
Nasal tip support mechanisms
3 major, 6 minor
- Size, shape, resiliency of LLC
- Attachment of LLC to caudal septum
- Attachment of LLC to ULCs at scroll region
- Interdomal ligament
- Cartilaginous dorsal septum
- Sesamoid complex
- Attachment of LLC to overlying SMAS and skin
- Nasal spine
- Membranous septum
Internal nasal valve
Narrowest segment of nasal cavity
Greatest resistance to nasal airflow
Borders: septum, head of Inf turb, caudal edge of ULC, pyriform aperture
ULC to septum is 10-15 deg in Whites
Causes of static narrowing or dynamic collapse and subsequent nasal obst at the INV
Prior surgery Trauma Septal deviation Inf turb hypertrophy Scarring Synechiae Congen malformations
