lacrimal bone


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Related to lacrimal bone: Vomer bone

lac·ri·mal bone

[TA]
an irregularly rectangular thin plate, forming part of the medial wall of the orbit posterior to the frontal process of the maxilla; it articulates with the inferior nasal concha, ethmoid, frontal, and maxillary bones.
Synonym(s): os lacrimale [TA], os unguis

lacrimal bone

n.
A thin irregularly rectangular plate forming part of the medial wall of the eye socket behind the frontal process of the maxilla.

lac·ri·mal bone

(lak'ri-măl bōn) [TA]
An irregularly rectangular thin plate, forming part of the medial wall of the orbit behind the frontal process of the maxilla; it articulates with the inferior nasal concha, ethmoid, frontal, and maxillary bones.

lacrimal bone

A small plate of bone, situated just inside the inner wall of the eye socket (orbit), with a shallow hollow to accommodate the LACRIMAL SAC.

orbit 

A rigid bony cavity in the skull which contains an eyeball, orbital fat, the extraocular muscles, the optic nerve, nerves and blood vessels, lacrimal system and fibrous tissue of various kinds. This packing serves to keep the eyeball reasonably well fixed in place as it rotates. The orbital cavity has the approximate form of a pyramid. The walls of the orbital cavity are formed by seven bones. The medial wall of the orbit consists of: (1) the frontal process of the maxilla (maxillary); (2) the lacrimal bone; (3) the lamina papyracea of the ethmoid; and (4) a small part of the body of the sphenoid. The floor of the orbit consists of: (1) the orbital plate of the maxilla; (2) the orbital surface of the zygomatic (malar) bone and (3) the orbital process of the palatine bone. The lateral wall of the orbit consists of (1) the orbital surface of the greater wing of the sphenoid, and (2) the orbital surface of the zygomatic. The roof of the orbit is made up mainly by the frontal bone and behind this by the lesser wing of the sphenoid. The orbit is lined with a membrane of tissue called the periorbita (or orbital periosteum) which extends to the orbital margin (anterior rim of the orbit) where it becomes continuous with the periosteum covering the facial bones. The periorbita is loosely attached to the bones except at sutures, foramina and the orbital margin where it is firmly attached. The bones are much thicker at the margin (rim) than they are along the walls of the orbital cavity. There are many apertures and gaps in the orbit through which blood vessels and nerves pass (see Table O4). See orbital axis; optic canal; inferior orbital fissure; superior orbital fissure; orbital fracture; cavernous haemangioma; lamina papyracea.
Table O3 Bones forming the walls of the orbit
roofmedial wall
1. frontal1. maxilla
2. lesser wing of sphenoid2. lacrimal
3. ethmoid
4. sphenoid
floorlateral wall
1. maxilla1. greater wing of sphenoid
2. zygomatic
3. palatine2. zygomatic

Table O4 Orbital apertures
aperturelocationcontents
optic canalat the apex (in lesser sphenoid)optic nerve
ophthalmic artery
sympathetic nerve fibres
superior orbital fissureat the apex (gap between greater and lesser sphenoid)III, IV, V, VI nerves
sympathetic nerve fibres
ophthalmic vein
recurrent lacrimal artery
inferior orbital fissurebetween lateral wall and posterior part of the floorinfraorbital nerve
zygomatic nerve
branch of inferior ophthalmic vein
nerve fibres from the
pterygopalatine (sphenopalatine)
ganglion to orbital periosteum
ethmoidal foramina (anterior and post.)medial wall (frontal/ethmoidal suture)ethmoidal vessels
ethmoidal nerve/external nasal nerve
zygomatic foramenlateral wallzygomatic nerve and vessels
nasolacrimal canalmedial wall (maxilla/lacrimal)nasolacrimal duct

lac·ri·mal bone

(lak'ri-măl bōn) [TA]
An irregularly rectangular thin plate, forming part of the medial wall of the orbit behind the frontal process of the maxilla; it articulates with the inferior nasal concha, ethmoid, frontal, and maxillary bones.
References in periodicals archive ?
With the help of mucoperiosteal elevator, nasal mucosawas stripped from the lacrimal bone to avoid damage to the nasal mucosa.
Nasal mucoperiosteum was incised and then excised in the diameter of 5 mm to 8 mm to expose lacrimal bone at the anterior end of middle turbinate.
The operation of Dacryo-cysto-rhinostomy is designed to affect the drainage of tears and infected secretions from the lacrimal sac into the middle meatus of the nose by-passing the nasolacrimal duct by creating a new passage in the lacrimal bone and nasal mucosa.
The bone is resected from the maxillary line anteriorly and extended posteriorly up to the lacrimal bone. Lacrimal sac is thus exposed.
The lamina papyracae was fractured and the nasal mucosa was stripped from the lacrimal bone to avoid damage to it.
The major affected bones are those which undergo intramembranous ossification such as cranial vault, clavicles, maxilla, nasal, and lacrimal bones.[sup][5] It is characterized by the absence of the clavicles, which usually occurs in 10% of cases or the presence of hypoplastic clavicles which allow the hypermobility of shoulders that can move it up to the medial plane of the body.
Depending on the degree of pneumatization, agger nasi cells can be bounded anteriorly by the frontal process of the maxilla, anterolaterally by the nasal and lacrimal bones, posterolaterally by the lamina papyracea, superiorly by the frontal sinus, inferolaterally by the uncinate process, and posteriorly by the anterior ethmoid complex.
1, 4 and 5) was articulated anteriorly with incisive bone as also reported in dog (Miller et at.), in horse (Getty), in chital (Kumawat et al.) and in tiger (Joshi) while the nasal bones articulated with lacrimal bones in ox (Raghavan) and in camel (Singh).
The zygomatic and lacrimal bones can also present themselves underdeveloped.
Facial and morphometric studies have shown that patient with narrow face and flat nose as well as underdeveloped lacrimal bones and maxilla have a higher incidence of dacryocystitis which leads to Nasolacrimal duct obstruction.