2. INTRODUCTION
Fractures of the frontal bone occur among 2 to 15% of patients with
facial fractures.
Its fracture can cause devastating complications because of
its close proximity to the brain, eyes, and nose.
Most victims are male (66–91%) and young (usually 20–30 yr
of age, range 6–72 yr)
Injuries are sustained in motor vehicle or motorcycle collisions
(44–85%)
The frontal bone is like half of a shallow, irregular cap forming
the
forehead or frons .
It has three parts and contains two cavities, THE
FRONTAL SINUSES.
3. EMBRYOLOGY
The frontal bone is an
intramembranous bone that develops
from 2 paired structures that begin to
ossify at the 8th or 9th week in utero.
The ossification begins in the frontal
processes of the squamous regions,
progresses to the orbital and
squamous regions, and reaches the
frontal and temporal regions by the
12th week.
The metopic suture in the midline
closes during the second year of life.
The forehead is displaced anteriorly
by sutural growth, inner table
resorption, and outer table deposition
4. The frontal sinus is Absent at birth
The frontal sinuses are derived from the
frontal recess portion of the middle
meatus or occasionally from an air cell
of the ethmoid infundibulum
Initial pneumatization begins during
the 4th month in utero.
Secondary pneumatization begins at the
age of 6 months to 2 years and develops
laterally and vertically.
The sinuses are radiologically evident at
5 to 6 years of age.
Most pneumatization is completed by the
time the child is 12 to 16 years old but it
continues until the age of 40 .
5.
6. SURGICAL ANATOMY
From the nasion the bone extends approximately 12.5 cm
superiorly,8.0 cm laterally, and 5.5 cm posteriorly.
Two frontal tuberosities are noted lateral to the midline and superior
to the supraorbital rim.
The thickest area of the bone is the supraorbital rim from the
frontozygomatic process to the nasal bones.
7. The supraorbital foramen are located at the most superior portion of
the orbital rim.
The supratrochlear foramen is located medial to the supraorbital
foramen or notch and lateral to the nasal bones.
A spine or concavity exists on the frontal bone along the medial
anterior orbital roof; the trochlea of the superior oblique muscle is
attached to this spine
8. FRONTAL SINUSES are paired air filled asymmetric triangular cavity lined by
pseudo stratified ciliated columnar epithelium found within the frontal bones and
are separated by a frontal septum.
The dimensions are-
Height 32mm
Width 26mm
Depth 17mm
Surface area 720 mm2
The outer and inner bony walls are
referred to as inner and outer tables .
The anterior wall of the sinus is stronger
than the posterior wall, but it also has low
resistance to either low-energy or high-
energy impact.
The posterior wall of the sinus is thinner
and weaker and separates the sinus from
the dural covering of the brain in the ACF
9. The sinus floor consists of membranous bone and is the thinnest of the sinus
boundaries.
Importantly, the floor of the frontal sinus is on average 3.1 mm below the
nasion (i.e., the frontonasal suture).
Drainage of the frontal sinus is variable. A true FND exists in only 15% of
the population, varying from a few millimeters to 1 cm in length. In the
remaining 85%, the frontal sinus drains directly into the anterosuperior
portion of the middle meatus via an ostium without a true duct or
occasionally by a communication through the ethmoids.
10.
11.
12. FUNCTIONS OF FRONTAL
SINUS
Production and storage of mucus
Resonator for voice
Humidification and warming of inhaled
air
Accesory area of olfaction.
Conservation of heat from the nasal
fossae
Definition of facial contour
Surge tank to dampen the pressure
differential that develops during
13. DIAGNOSIS
The diagnosis of the frontal sinus fracture based on the proper
history and physical examination of the patient which includes
inspection and palpation of the affected area.
The detailed history includes the following points:
1. Information about events
2. Visual difficulties
3. Numbness
4. Pain
5. Rhinorrhea
6. Sense of smell
7. Previous history of nasal or sinus disease surgery.
17. CLASSIFICATIONS
1)Stanley’s Classification of Frontal Sinus Fracture
• Type I: Anterior Table Fracture
–– Isolated to anterior table
–– Accompanied by supraorbital rim fracture
–– Accompanied by naso-ethmoid complex fracture
• Type II: Anterior and Posterior Table Fractures
–– It is a linear fracture either on transverse direction or in
vertical direction
• Type III: Comminuted Fractures
–– Isolated to both tables
–– Accompanied by naso-ethmoid complex fracture
18. 2)Gonty Et al. Classification of Frontal Sinus
Fracture
• Type I: Anterior Table Fracture
–– Isolated to anterior table
–– Accompanied by supraorbital rim fracture
–– Accompanied by naso-ethmoid complex fracture
• Type II: Anterior and Posterior Table Fractures
–– A linear fracture either on transverse direction or in
vertical direction
–– Comminuted fracture either isolated to both tables or
accompanied by naso-ethmoid complex fracture
• Type III: Posterior Table Fracture
• Type IV: Through and Through Frontal Sinus Fracture
33. REFERENCES
Maxillofacial trauma by Peter Ward Booth
Petersons Principles of Oral and Maxillofacial Surgery
2 Vol. set by Michael Miloro, G. E. Ghali, Peter E.
Larsen
Fonseca Volume 3 –Trauma
Grays anatomy – 41ST Edition
McMinn and Abrahams' Clinical Atlas of Human
Anatomy