What Is the Lacrimal Bone?

Lacrimal bones are a thin pair of bones that are the size and shape of a fingernail. It is the smallest bone on the face.

Lacrimal bones are a thin pair of bones that are the size and shape of a fingernail. It is the smallest bone on the face.

Chinese name

Lacrimal bone

Foreign name

lacrimal bone

Location

Anterior side

Tearbone Introduction

These bones are on the posterolateral wall of the nasal bone and the medial wall of the orbit. The lacrimal fossa contains a lacrimal sac. Anterior maxillary, posterior ethmoid labyrinth orbital plate.

Lacrimal bone

Anatomy of the lacrimal face skull

The facial skull includes pairs of the maxilla, the sacrum, the sacrum, the lower turbinate, the lacrimal bone, the nasal bone, and the individual vomera, mandible, and hyoid bones.

The upper jaw is larger and irregular, forming the upper alveolar arch, the bottom and outer walls of the nasal cavity, the top of the oral cavity, and the inferior wall of the orbit. It also participates in the composition of the infratemporal fossa and the pterygopalatine fossa. Projections (Figure 1). The maxillary body has four sides: the nasal plane, the anterior lacrimal sulcus and the lacrimal bone synthesize a nasolacrimal duct, and the maxillary sinus fissure on the posterior upper part of the nasal plane, which is the maxillary sinus opening; tube. The orbital surface is triangular in shape, and the front is bordered by a sharp lower orbital edge. The trailing edge is free and obtuse, and serves as the anterior boundary of the infraorbital fissure. The infraorbital canal continues from the infraorbital canal starting from the infraorbital fissure.

Lateral view of maxilla

Figure 1 Lateral view of the maxilla (right side)

1. Frontal process 2. Infraorbital foramen 3. Alveolar process 4. Posterior superior alveolar hole 5. Infraorbital sulcus

Passed by. Front, front and outside, the inner nasal notch meets left and right, forming a large part of the pear-shaped hole; the front edges of the two sides are divided into forward nasal spines. Below the temporal, the bulge is the anterior wall of the infratemporal fossa, and the alveolar hole on the wall communicates with the alveolar tube in the wall; After the frontal process points up, connect the frontal bone. The condyles are outwardly connected to the patella. The condylar process extends horizontally inward, with the incisor tube passing at its medial edge, the sulcus below, and the anterior part of the epiphysis on both sides. The alveolar process protrudes downward, and the alveolar arch is formed on both sides, and the teeth are fixed in the alveolar. The maxillary sinus is in the body and has a pyramidal shape. The bottom surface of the sinus is lower than the maxillary sinus hole, so the fluid in the sinus is not discharged smoothly.

The sacrum and sacrum are "L" -shaped, located behind the maxilla and before the sphenoid bone, forming the posterior part of the epiphysis, becoming the outer side and bottom of the nasal cavity, and the top of the oral cavity. The inner wall of the nest. The patella is divided into a vertical plate, a horizontal plate, and three protrusions. The vertical plate is rectangular, and the upper edge is separated by the chrysalis notch from the anterior orbital process and the rear sphenoid process; the posterior edge and the horizontal plate join out a conical process, extending to the postero-inferior and lateral sides, and then connecting to the wing process. The medial side is the nasal surface, and the sieve ridge and turbinate anteroposterior are connected to the middle and lower turbinates. The lateral surface is the maxillary surface connected to the maxilla, and the sacral sulcus and the sulcus of the same name of the maxilla form a large sacral duct, opening in the epiphysis. The orbital process forms a small part of the infraorbital wall. The sphenopalatine notch forms the sphenopalatine hole throughout the skull, connecting the nasal cavity with the pterygopalatine fossa. The horizontal plate constitutes the posterior epiphysis, and the posterior edges of the two sides are combined at the midline and protrude backward to form the posterior nasal spine. The medial edge of the nasal surface protrudes upwards into a nasal condyle, which is connected to the vulva.

The sacrum The sacrum is diamond-shaped, located just below the orbit, forming a bony bulge on the cheek; it has three sides and two processes. The lateral surface is the buccal surface, and it protrudes to the front and the outside. This surface has 1 to 2 faces, and there are phrenic facial nerves. The temporal surface is recessed inward and backward to form the anterior lateral wall of the temporal fossa, which has the iliac temporal foramen. The orbital surface is smooth and depressed, forming a considerable part of the orbital margin. The face has a zygomatic orbital foramen, which may be one, or has been divided into two holes, which are directly connected to the zygomatic face and the temporal foramen. The frontal process and the temporal process are connected with the bones of the same name.

Inferior turbinate The inferior turbinate is a free-standing bone piece that is thin and curly. It is connected to the maxilla and sacrum on the outside wall of the nasal cavity, and its lower edge is free. The upper edge has three processes: the maxillary process is connected to the maxilla; the anterior lacrimal process is connected to the lower end of the lacrimal bone; the posterior ethmoid process is connected to the ethmoid hook process. The nasolacrimal duct runs down from the orbit into the lower nasal passage of the inferior turbinate.

Lacrimal bones Lacrimal bones are the smallest and most fragile individual bone fragments in the skull, located in the front of the medial side of the orbit; The orbital surface is divided into two parts by the posterior posterior condyle, and the anterior part is the lacrimal sulcus, which houses the lacrimal sac and continues down to the nasolacrimal duct. The lower end of the tear posterior condyle is bent forward and upward to form a tear hook, which is the starting point of the nasolacrimal duct. The inner side is part of the outer side wall of the nasal cavity.

The nasal bones and nasal bones are rectangular, narrow upper and lower, and located on the back of the nose. The left and right bones are spliced. Vessel holes can be seen on the outside; the ethmoidal groove on the inside is passed by the anterior ethmoidal nerve.

The vulva is a quadrilateral, thin, flat, located in the middle of the nasal cavity, forming the posterior inferior part of the nasal septum. The upper edge is thicker, and the vomera wing is slightly protruded to the sides, and the upper part is connected to the butterfly mouth; the lower edge is connected to the epiphysis, the front edge is combined with the septal cartilage and the ethmoid bone vertical plate, and the trailing edge is free to become the medial edge of the hind nostril.

Mandible The mandible is an independent bone with strong bone quality. It is located in the anterior and inferior part of the face. It consists of an arched mandibular body and bone plates standing on both sides, that is, the mandibular branch. The mandible is divided into inner, outer and upper and lower edges. Triangular ridges are visible below the outer midline, with zygomatic nodules on both sides; there is a zygomatic hole leading to the upper back about the second double canine. The oblique line extending from the zygomatic tubercle to the posterior edge of the mandibular branch continues. The lower edge is round and thick, also known as the base of the mandible, and the shallow depression on the inner surface near the midline is the diabdominal fossa with diabetic muscle attachment. Two pairs of sacrospinalis can be seen below the median line of the inner surface, which are the starting points of the tongue muscles. From there, the mandibular hyoid muscle line extends from above. The line has a sublingual gland depression above the line and below the posterior line. The submandibular gland is concave. The upper edge is the alveolar part, which constitutes the lower alveolar arch. The mandibular branch is a square bone projecting from the posterior part to the posterior part, which is divided into two sides, four edges and two processes. The rough surface of the outer posterior part is masseter trochanter. The part of the inner surface corresponding to the masseter tuberosity is the pterygoid tuberosity. On the inner side of the branch, there is a mandibular foramen at about the center, which leads into the mandibular canal, and the tube branches again to the root of the tooth, through which the alveolar nerve and blood vessels pass. The lamellar bone process at the anterior medial edge of the mandibular foramen is called the mandibular lingual, and the mandibular sulcus goes from here to the anterior inferior to the mandible. There is a mandibular notch in the upper margin. The coronoid process before the notch is attached by the temporal muscle. The subsequent condylar process can be divided into the mandibular head, mandible neck, and pterygoid muscle anterior neck. The mandibular head and the mandibular fossa of the temporal bone form the temporomandibular joint (Figure 2).

lower jaw

Figure 2 Mandible

1. Mandibular coronoid process 2. Mandibular foramen 3, Sacral hole 4, Mandibular branch 5, Mandibular condyle

Hyoid Hyoid bone is an independent small bone that is "U" shaped and lies between the tongue and throat in front of the neck. The hyoid bone is divided into a body and a pair of large and small horns. The central part of the hyoid bone is the body, with large horns protruding upwards and backwards; the small horns are attached above the junction between the body and the large horns, and there is a styloid process between the small horns and the styloid