Osteomyelitis is a bone infection, more common in children than adults, that can start in the dental sac and spread to the maxilla. Symptoms include cheek swelling, eyelid edema, nasal discharge, and fever. Treatment involves high doses of antibiotics, drainage of any abscesses, and removal of infected bone fragments. Orbital complications are a common result of sinusitis, especially from the ethmoid sinus in children. This can lead to subperiosteal abscesses that displace the eyeball, orbital cellulitis spreading infection between orbital structures, or intraorbital abscesses seen on imaging. Left untreated, vision loss, meningitis, or cavernous sinus thrombosis can occur.

1. Osteomyelitis
 It is the infection of bone marrow.
- It is seen in infants and children
than adults because of presence of spongy bone in anterior
wall of maxilla. Infection may start in dental sac and then
spread to the maxilla, but less often it is primary infection
of maxillary sinus.
Clinical Features: Erythema, Swelling of cheek, oedema of
lower lid, purulent nasal discharge and fever.
Subperiosteal abscess followed by fistulae may form in
infraorbital region, alveolus or palate or in zygoma.
Treatment- large doses of antibiotics, drainage of any abscess
and removal of sequestra.

2. 2. - More often seen in
adults.
Results from acute infection of frontal sinus either directly
or through the venous spread. It can also follow trauma or
surgery of frontal sinus in the presence of acute infection.
Pus may form externally under the periosteum as soft
doughy swelling, or internally as extradural abscess.
Treatment- large doses of antibiotics, drainage of abscess
and trephening of frontal sinus through its floor.

3. Orbital Complications
 The orbit is the structure most commonly involved in
complicated sinusitis.
 Orbital extension is usually the result of ethmoid sinusitis.
 Children are more prone to orbital complications,
probably secondary to high incidence of URI and
sinusitis.

6. Subperiosteal abscess
 Pus collects outside the bone under the periosteum.
 A subperiosteal abscess from ethmoids forms on the
medial wall of orbit and displaces the eyeball forward,
downward and laterally.
 From the frontal sinus, abscess is situated just above
and behind the medial canthus and displaces eyeball
downwards and laterally
 From the maxillary sinus, abscess forms in the floor of
the orbit and displaces the eyeball upwards and
forwards.

7. Orbital Cellulitis
 When pus breaks through the periosteum and finds its
way into the orbit, it spreads between the orbital fat,
extraocular muscles, vessels and nerves.
 Clinical features will include oedema of lids,
exophthalmos, chemosis of conjunctiva and restricted
movements of the eye ball. Vision is affected causing
partial or total loss which is sometimes permanent.
Patient may run high fever.
 Orbital cellulitis is potentially dangerous because of the
risk of meningitis and cavernous sinus thrombosis.

8. Orbital Abscess
 Intraorbital abscess usually forms along lamina
papyracea or the floor of frontal sinus.
 Clinical picture is similar to that of orbital cellulitis.
 Diagnosis can be easily made by CT scan or ultrasound
of the orbit.
 Treatment is i.v. antibiotics and drainage of the abscess
and that of the sinus (ethmoidectomy or trephination of
frontal sinus).

9. Superior orbital Fissure syndrome
 Infection of sphenoid sinus can rarely affect structures
of superior orbital fissure. Symptoms consist of deep
orbital pain, frontal headache and progressive paralysis
of CN VI, III and IV, in that order.
Orbital apex Syndrome
It is superior orbital fissure syndrome with additional
involvement of the optic nerve and maxillary division of
the trigeminal (V2)