NOSE
Nose and Paranasal Sinuses
Introduction to the anatomy and function of the nose and surrounding sinuses.
The Facial Skeleton
Importance of understanding the bony facial skeleton:
Critical in trauma management.
Assist in diagnosis and treatment of inflammatory diseases of the facial skeleton.
External Nose
Various structures defining the appearance:
Nasal bone
Lateral nasal cartilage
Frontal process of maxilla
Lateral crus of alar cartilage
Minor alar cartilage (accessory)
Medial crus of alar cartilage
Fatty tissue
Nasal Cavities
Components within the nasal cavities:
Nasal Vestibule
Nasal Septum
Nasal Valve
Lateral nasal wall
Choana
Medial crus of alar cartilage
Nasal Cavity
Cavity divided into right and left halves by nasal septum.
Opens anteriorly through nostrils (anterior nares)
Opens posteriorly into the nasopharynx (posterior nasal aperture)
Bony Skeleton of the Nose
Roof:
Anterior: Nasal part of the frontal bone + Nasal bone
Middle: Cribriform plate of the ethmoid bone
Posterior: Body of the sphenoid bone
Floor:
Anterior: Palatine process of the maxilla
Posterior: Horizontal plate of the palatine bone
Medial wall (nasal septum):
Postero-inferior: Vomer
Superiorly: Perpendicular plate of the ethmoid bone
Antero-inferior: Septal cartilage
Lateral Wall of the Nose
Divided into three areas: A. VestibuleB. Nasal conchae and meatuses: 1. Conchae covered with mucous membrane (superior, middle, inferior nasal conchae)2. Meatuses (depressions): superior, middle, inferior meatuses- Superior meatus receives posterior ethmoidal air sinus opening.
Nasal Drainage and Blood Supply
Arterial supply:
Sphenopalatine artery (branch from maxillary artery)
Septal branch of the superior labial artery (from facial artery)
Ascending branch of the greater palatine artery (from maxillary artery)
Anterior and posterior ethmoidal branches of the ophthalmic artery
Kieselbach's plexus: Common site for epistaxis (nosebleeds).
Nerve Supply
Innervation details:
Anterior ethmoidal nerve
Posterior ethmoidal nerve
Various branches from the ophthalmic and maxillary nerves
Paranasal Air Sinuses
Definition: Air-filled spaces surrounding nasal cavity; functions include warming, humidifying inspired air, reducing skull weight, adding voice resonance.
Types of sinuses:
Maxillary sinus (inside maxilla)
Frontal sinus (between frontal bone plates)
Sphenoid sinus (inside sphenoid body)
Ethmoid sinus (in lateral ethmoid bone)
Symptoms and Diagnosis of Nasal Conditions
Common complaints:
Nasal obstruction
Discharge
Epistaxis
Specific allergy history
Headaches
Olfactory dysfunction
Facial pressure/pain
Clinical Examination Techniques
PCR: Anterior and posterior rhinoscopy
Nasal endoscopy: Main modern examination method for detailed assessment.
Imaging Techniques
Conventional radiographs
Computed Tomography (CT)
Magnetic Resonance Imaging (MRI)
Ultrasound
Tumors of the Nose and Sinuses
Benign tumors include inverted papilloma and osteomas.
Malignant tumors: predominantly epithelial (e.g., squamous cell carcinoma).
Symptoms of sinonasal tumors often manifest late; include obstructive symptoms and facial pain.
Malformations of the Nose
Conditions like choanal atresia & frontobasal dysraphias can impact airflow and develop secondary complications
Surgical interventions may be necessary for cases like choanal atresia to alleviate airway obstruction.