What Is the Nasal Bone?

Nasal bone is a pair of small bones located on the back of the nose, rectangular, thick and thin, supporting the back of the nose. The nasal bone is connected to the frontal bone, the nasal cartilage is connected below, the maxilla is connected to the lateral side, and the contralateral nasal bone is connected to the medial side. The nasal bones are paired and are located on both sides of the lower midline of the frontal bone, forming the dorsal nasal. There are many opportunities for nasal bone injury, and it is often accompanied by multiple injuries.

Nasal bone is a pair of small bones located on the back of the nose, rectangular, thick and thin, supporting the back of the nose. The nasal bone is connected to the frontal bone, the nasal cartilage is connected below, the maxilla is connected to the lateral side, and the contralateral nasal bone is connected to the medial side. The nasal bones are paired and are located on both sides of the lower midline of the frontal bone, forming the dorsal nasal. There are many opportunities for nasal bone injury, and it is often accompanied by multiple injuries.

Chinese name

Nasal bone

Foreign name

nasal bone

Belong to

Facial skull

Shape

Long

Features

Upper narrow and wide, thick upper and thin upper

On

Frontal nose

Next

Superior nasal cartilage

Outside connection

Maxillary frontal process

Inside connection

Contralateral nasal bone

Followed by

Ethmoid median plate, nasal septum cartilage

Nasal bone imaging

The normal structure of the nasal area and its HRCT manifestations that are easily confused with fractures:

1. Nasal suture: a suture for tightly connecting the bones of the nose. (1) Nasal suture: the seam between the left and right nasal bones. Coronal plane: only visible on 1 or 2 layers of images, it is jagged, thin straight line or "S" line shadow, which is related to the development of left and right nasal bones. Horizontal axis plane: From the appearance of the nasal bone to the disappearance, it can be seen on each layer of the image, and it is a short-line shadow that is vertical or slightly oblique to the nasal bone. (2) Nasomaxillary suture: the suture connection between the full length of the outer edge of the nasal bone and the inner edge of the frontal process of the maxilla. It is the bone fracture that is most likely to be confused with the fracture on the image. The HRCT scan showed that the nasal and maxillofacial morphology can be expressed as dilated, flat, occlusal, interstitial bone, and thin nasal bones at different scanning levels. Among them, the swollen, occlusal, intersegmental bones and thin nasal bones are characteristic morphologies As long as one of them is observed on a continuous level, it can be confirmed as a nasal maxillary suture, and the boundary between the nasal bone and the maxillary frontal process can be clarified. Fracture lines do not have this characteristic form. In addition, the depression in the back of the nasal bone, the depression near the lower edge is more obvious, and its lateral maxillary frontal process runs in a continuous arc. When the outer edge of the lower end of the nasal bone is too depressed or straight (related to the development of the nasal bone), the lower end of the nasal bone is scanned in a coronal plane. The axial scan of the nasal bone was normal in shape and intact, and there was no separation and dislocation of the nasal and maxillary sutures, which could exclude fractures. (3) Nasal frontal suture and fronto-mandibular suture: The seam between the nasal bone and the frontal nasal process is the nasal frontal suture. The suture connection between the upper edge of the maxilla frontal process and the frontal nasal process is the frontomaxillary suture. The coronal plane is clearly visible. Appears as a translucent, small, sawtooth-like translucent shadow of varying depths, tightly connected. Because these two bone sutures are located at the lower part of the face and the bone is thicker at the joint formation, fractures occur less frequently, and suture separation and dislocation are prone to occur during trauma. The fracture line appears outside the normal bone suture and is fissure-shaped, showing sharpness and irregularity, and may be dislocated, overlapping, and collapsed, often accompanied by swelling of adjacent mucosa and soft tissues, often involving the lower and middle nasal bones. In addition, the bone suture area is weak in bone Zone, easy to separate and dislocation under the action of external force.

2. Interstitial bone: An image formed when the scanning line traverses the gap between the jagged bones. Found in the nasal suture, nasal jaw suture. It is spot-shaped, next to the bone suture, and running in line with adjacent connecting bones. Nasal and maxillary sutures are prone to misalignment and angulation during trauma, and free osseous fragments can be seen after the occlusal bones are broken, but they are inconsistent with the adjacent connecting bones.

3. Nasal foramen: Some small foramen on the nasal bone, with small veins running vertically or obliquely in the middle and lower part of the nasal bone. The coronal plane is better, showing dot-like, small round hole-like shadows, and the horizontal axis scans are linear translucent shadows that run vertically or obliquely on the nasal bone at the corresponding position, and some do not penetrate the nasal bone. Smooth and natural, unlike sharp fracture line shadows.

4. Hook-shaped nose: The lower segment of the nasal condyle is mutated, and the adduction is obvious. A coronal scan shows a free small bone fragment before the nasal septum, and a horizontal axis scan shows no abnormalities in the nasal bone. The lateral positioning piece can show that its overall shape is hook-shaped.

5. Indentation on the inner surface of the nasal bone: There are several longitudinal grooves and oblique grooves on the inner surface of the nasal bone, which are the indentations of the anterior ethmoid nerve and blood vessels. HRCT horizontal axis scan of the nasal bone is uneven, and some bones are thin but continuous. Multiple stripe-shaped, feather-like, and honeycomb-shaped shadows can be seen on the surface of the nasal bone on the molybdenum target X-ray magnification photography and computer digital photography (DR) side film, which are easy to be mistaken for fracture lines.

Nasal bone related diseases and treatment

1. The nose is located in the middle of the head and face of the human body, which is a relatively prominent part. In the maxillofacial trauma, it is easy to cause a nasal fracture. The literature reports that the nasal fracture accounts for 37,7% of the posterior fracture of the trauma. The nose protrudes from the face in the shape of a triangular pyramid, which is susceptible to external force injuries and fractures. The nasal bone, maxilla, and frontal bone are the bones that support the external nose, and the nasal septum supports the external nose. The frontal process of the maxilla is connected to the lateral nasal cartilage by tough connective tissue, which determines the width of the back of the nose. Therefore, external forces of different strengths and directions acting on the nose are not only prone to nasal bone fractures, but also often accompanied by nasal septum fractures. Most of the adjacent nasal bone structures are relatively thin, and compound injuries are easy to form after fracture. For nasal bone fractures, if not diagnosed and treated in time, it often leads to sequelae such as external nasal deformity, nasal septum deviation, and nasal dysfunction (nasal congestion, headache, runny nose). Therefore, after nasal trauma, it is necessary to achieve correct diagnosis, timely treatment and ideal remedial measures.

2. The classification of common nasal bone fractures is simple nasal bone fracture, including unilateral nasal bone fracture, bilateral nasal bone fracture, nasal bone fracture with nasal suture separation; composite nasal bone fracture, including nasal bone fracture with nasal septum fracture, nasal bone fracture With maxillary frontal process fracture, nasal fracture with orbital fracture. According to the fracture line direction, it can be divided into: transverse fracture, oblique fracture, comminuted fracture and so on.

3. Common symptoms and signs of nasal bone fractures: nosebleeds, swelling of the nose and face, purple eyelid bruising, nasal congestion, tearing of soft tissues, and deformities of the external nose to varying degrees (collapse of the nose bridge, depression of the back of the nose, etc.). Nasal palpation is also important. If palpation, cramping, tenderness, shortening of the nose, or widening of the root of the nose are indicated, a nasal bone fracture is indicated. For patients with severe compound injuries, there may be serious complications: headache, vomiting, disturbance of consciousness, cerebrospinal fluid rhinorrhea, craniocerebral trauma such as skull fracture, maxillofacial fracture, limb trunk spine fracture, etc.

4. Treatment In order to avoid the sequelae of external nose deformity and nasal dysfunction, the reduction of nasal bone fracture should be carried out as soon as possible. Patients with stable vital signs and good general conditions should strive for early rehabilitation of fractures, preferably within 2 to 3 hours after trauma. If the local swelling is obviously accompanied by a large amount of bleeding in the nasal cavity, it can last 5 to 10 days, but it should not exceed 14 days. Otherwise, dislocation healing due to epiphyseal formation may not be satisfactory. The fracture healing process can be divided into three stages: the hematoma mechanized evolution stage, the primitive epiphyseal formation stage, and the epiphyseal reconstruction and shaping stage. The hematoma mechanization evolution phase takes approximately 2 weeks to complete initially. Nasal bone fractures that had not been reduced for more than 2 weeks, with epiphyseal formation at the fracture site, and difficult reduction, were classified as old fractures.

The main treatment methods are simple reduction of nasal bone fractures, nasal endoscopic nasal bone fracture restoration, and old nasal bone fracture restoration.

5. Efficacy evaluation Generally, the clinical evaluation is mainly based on the appearance and nasal ventilation. Cure: Double nasal ventilation is good, the external nose is not deformed, and the nasal septum is basically centered. Improvement: There is still a slight deflection or collapse of the external nose, and the nasal septum is slightly deflected, but it is better than before treatment and the nasal ventilation function is significantly improved; Ineffective: Nasal appearance Obvious deformity, postoperative nasal bone fracture displacement and nasal septum deviation did not improve, there were still symptoms of poor ventilation.

It should be noted that different fracture types should choose different treatment start times and treatment options.