Lecture 1: Introduction and Surface Anatomy of the Head and Neck PDF

Lecture 1: Introduction and Surface Anatomy of the Head and Neck and Surface Anatomy DEN 1112  Learning Objectives Define anatomical terms specific to head and neck anatomy Discuss the clinical applications of head and neck and surface anatomy L...

Lecture 1: Introduction and Surface Anatomy of the Head and Neck and Surface Anatomy DEN 1112  Learning Objectives Define anatomical terms specific to head and neck anatomy Discuss the clinical applications of head and neck and surface anatomy Locate surface landmarks of the head and neck regions Integrate an understanding of surface anatomy into clinical practice  Why is it important for a DH? The dental professional must have a thorough knowledge of head and neck anatomy when performing the extraoral and intraoral examination. 1. Determine the presence of abnormalities or lesions 2. Indicate their etiology and amount of involvement 3. Use descriptive terminology of the lesion and its location 4. Knowledge of anatomical landmarks is necessary for performing dental radiology procedures (placement of the intra-oral films, mounting of radiographs) 5. Administration of local anesthesia is based on landmarks of the head and neck 6. Provide background for understanding the spread of dental infection The nomenclature of anatomy is based of the body in anatomic position. Standing erect Arms at side, palms and toes directed forward Eyes looking forward  Key Terms Superior Posterior, Dorsal Anterior, Ventral Inferior Flat Surface Planes Midsagittal, or median - divides the body into right and left sides Coronal, or frontal - divides the body into anterior and posterior parts Transverse, or axial - divides the body horizontally into inferior and superior parts The transverse plane is always perpendicular to the midsagittal plane. Body Parts in Relationship to these Planes Medial - area closer to the midsagittal plane within the body Mesial - closer to the midsagittal within the teeth Lateral - area further away from the midsagittal plane Proximal - area closer to the midsagittal plane Distal - further from the midsagittal within the teeth Deep - structure located away from the body surface Superficial - structure located toward the surface of the body  Regions of the head Frontal Parietal Occipital Zygomatic Nasal Oral Infraorbita l Buccal Mental  Frontal Region Includes the forehead and the area superior to the eyes. Supraorbital ridge Inferior to the eyebrows More prominent in adult males Also called ‘superciliary’ Glabella A flat region between eyebrows Frontal eminence Prominence of the forehead More pronounced in children and females Examined by bilateral palpation  Parietal and Occipital Regions Covered by the scalp Scalp consists of layers of soft tissue overlying the skull and is covered by hair. Examining these areas is important because many lesions may be hidden from the clinician and patient. https://www.rdhmag.com/pathology/article/14200708/ski  Temporal and Auricular Region Temporal includes the superficial side of the head posterior to the eye Auricular includes the external ear Examined by: visual inspection and manual palpation  External Ear ⬤ Composed of an auricle and the external acoustic meatus ear is composed of an auricle or oval flap of ⬤ helix - ends inferiorly at the lobule the ear and the centrally located tragus - smaller flap of tissue external acoustic ⬤ anterior to the external acoustic meatus. meatus (EAM). ⬤ antitragus – flap of tissue opposite the tragus ⬤ intertragic notch – deep notch between the tragus and antitragus  Orbital Region Includes the eyeball and the supporting structures within the bony socket During an extraoral examination visually inspect the eyes with their movements and responses to light and action.  Nasal Region Includes the external nose During an extraoral examination visually inspect the external nose starting at the root of the nose and proceeding to the apex. Infraorbital, Zygomatic and Buccal Regions The infraorbital region is located inferior to the orbital region and lateral to the nasal region. DEN 1112  Infraorbital, Zygomatic and Buccal Regions The zygomatic region is lateral to the infraorbital region; it overlies the cheekbone, and the zygomatic arch. The zygomatic arch extends from just inferior to the lateral margin of the eye toward the upper portion of the ear. DEN 1112  Infraorbital, Zygomatic and Buccal Regions The buccal region is composed of the soft tissues of the cheek (muscles and fat). During an extraoral examination visually inspect and palpate bilaterally the infraorbital, zygomatic, and buccal regions, as well as the temporomandibular joint (TMJ). Infraorbital, Zygomatic and Buccal Regions During an extraoral examination visually inspect and palpate bilaterally the infraorbital, zygomatic, and buccal regions, as well as the TMJ.  Oral Region Includes the lips,oral cavity, palate, tongue, floor of mouth,and parts of the throat (pharynx). Lips During an extraoral examination bilaterally palpate the lips and visually inspect them in a systematic manner. Commissural lip pit Commissural lip pit A deep depression is seen at the labial commissure.  Oral Cavity ⬤oral cavity – area inside the mouth ⬤The jaws are within the oral cavity ⬤Underlying the upper lip is the upper jaw or maxilla(e). ⬤Underlying the lower lip is the lower jaw or mandible  Oral Cavity ⬤Structures closest to the facial surface are facial. ⬤Those facial structures that are also closer to the lips are labial. ⬤Facial structures closest to the inner cheek are buccal. ⬤Structures closest to the tongue are lingual. ⬤Those lingual structures closest to the palate are palatal.  View of buccal and labial mucosa Linea Alba Mucogingival junction Free mucosa (unattached) Attached gingiva  Linea Alba ⬤A variation on the buccal mucosa is the linea alba. ⬤A white ridge of raised callused tissue that extends horizontally where the maxillary and mandibular teeth occlude. Fordyce granules Clusters of sebaceous glands Fordyce granules. Most commonly observed on the lips and buccal mucosa. Appear as tiny yellow lobules A variant of normal  During an intraoral examination ask the patient to open their mouth slightly and gently pull the lips away from the teeth. Visually inspect and bidigitally palate the inner check using a circular compression.  Maxillary tuberosity Retromolar pad ⬤ A tissue-covered elevation on the maxilla just posterior to the most distal maxillary molar is the maxillary tuberosity. ⬤ On the mandible just posterior to the most distal mandibular molar is a dense pad of tissue, the retromolar pad. Frontal view of the oral cavity Maxillary vestibule Mandibular vestibule Gingiva and the associated landmarks Interdental papilla  During an intraoral examination retract the buccal and labial mucosa and visually inspect and digitally palate the vestibular area and gingival tissue using circular compression, including the maxillary tuberosity and retromolar pads.  Palate two parts: hard and soft ⬤hard palate ⬤incisive papilla ⬤palatine rugae ⬤soft palate ⬤median palatine raphe Have the patient tilt their head back slightly and extend their tongue. Depress the tongue, have the patient say “ah” and visually inspect. Use finger to palate hard palate. Torus Palatinus Torus palatinus or palatal torus is a bony protrusion on the palate, usually on the midline. Tongue- Dorsum Surface  Tongue Have the patient extend the tongue and wrap gauze around the anterior two thirds. Visually inspect and digitally palpate. Tongue - Ventral Surface and Floor of Mouth Tongue - Ventral Surface and Floor of Mouth Have the patient lift the tongue and visually inspect area. Observe salivary flow; bimanually palpate with the index finger intraorally and the opposite hand under the chin.  Short lingual frenum (Ankyloglossia) Bilateral mandibular tori Pharynx, or Throat 3 parts Nasopharynx Oropharynx Laryngopharynx Oral Cavity and Oropharynx fauces anterior faucial pillar posterior faucial pillar palatine tonsils  Mental Region Philtrum Nasolabial groove Visually inspect and bilaterally palpate the chin during an extraoral exam. Regions of the Neck The neck extends from the skull and mandible down to the clavicles and sternum. The regions of the neck can be divided into different cervical triangles. Regions of the Neck Sternocleidomastoid muscle (SCM) divides neck diagonally into: Anterior cervical triangle (larger) Posterior cervical triangle (smaller) The SCM is palpated along with the regions anterior and posterior to it during an extraoral exam. Thyroid The thyroid cartilage, “Adam's apple” at the midline Palpating the thyroid gland by placing one hand on one side of the trachea and gently displacing the thyroid tissue.