Oral Physiology PDF

ORAL PHYSIOLOGY Dr. Romeo T. Cruz Jr. DMD, MACT, EdD ORAL PHYSIOLOGY Branch of dentistry concerned with the study of functions and activities of the different structures found in the oral cavity  Stomatognathic System The stomatognathic system It encompasses various refers t...

ORAL PHYSIOLOGY Dr. Romeo T. Cruz Jr. DMD, MACT, EdD ORAL PHYSIOLOGY Branch of dentistry concerned with the study of functions and activities of the different structures found in the oral cavity  Stomatognathic System The stomatognathic system It encompasses various refers to the collective structures components, including the and functions involved in the teeth, jaws, temporomandibular process of chewing, joint (TMJ), muscles of swallowing, breathing and mastication, salivary glands, voice production. taste buds, and other oral structures  STOMATOGNATHIC SYSTEM Composed of structures of the mouth and jaws considered collectively as they subserve the functions of mastication, deglutition, respiration and speech. STOMA: Mouth. GNATHIA: Upper and lower jaws.  FUNCTIONS OF THE STOMATOGNATHIC SYSTEM ▪ 1. Mastication ▪ 2. Deglutition ▪ 3. Speech ▪ 4. Respiration  1. MASTICATION  > is a physiologic activity formed when there is normal occlusion in a cyclic movement.  > simply the chewing process. MASTICATION  > Purposes:  1. Physiological transformation of food.  2.Enhances growth & development of dento-alveolar structures through stimulation.  3. Stimulates salivary flow.  4.There is volatilization of food to increase appetite.  5. Protection of the individual from undesirable food components.  6. Help further develop or allow jaw bone to grow.  2. DEGLUTITION  > once the food is chewed, the next step is to swallow it.  > swallowing is a complex group of reactions to move food onwards in the digestive tract while preserving the airway DEGLUTITION  > transport of material from mouth to esophagus:  Adult swallow ◼ deglutition/swallowing  Infant swallow ◼- suckling – earliest means of food transport ◼ - sucking/drinking – fluid transport  3. SPEECH  > an expression of thought either written or spoken. SPEECH Speech is produced by bringing air from the lungs to the larynx where the vocal folds may be held open to allow the air to pass through or may vibrate to make a sound (phonation). Purposes: - Communication: Speech enables the exchange of thoughts, ideas, and emotions between individuals. - Articulation and pronunciation: Speech involves the precise movements of the mouth and vocal organs to produce clear and correct sounds. - Oral motor control: Speech requires coordination and control of the muscles involved in breathing, phonation, and articulation  4. RESPIRATION  > a continuous process closely associated with deglutition.  > also referred to as ventilation wherein there is the entrance of oxygen & release of carbon dioxide.  RESPIRATION Purposes: - Homeostasis: Respiration contributes to the maintenance of physiological balance, including the regulation of body temperature. *person gasping air through mouth - Energy production: The process of respiration generates energy in the form of ATP (adenosine triphosphate) through cellular respiration. - Gas exchange: Respiration facilitates the exchange of oxygen and carbon dioxide between the body and the environment. NINE STRUCTURAL COMPONENTS OF THE STOMATOGNATHIC SYSTEM: I. Basal bones superiorly- maxillary and palatine bones inferiorly- mandibular bone JAWS The jaws, also known as the mandible (lower jaw) and maxilla (upper jaw), provide the framework for the teeth and play a crucial role in the process of mastication. The mandible is the only movable bone in the skull and is connected to the skull through the temporomandibular joint (TMJ). The jaws work together to facilitate biting, chewing, and other oral functions. II. Muscles of Mastication 1. Temporalis muscle- elevates and positions the mandible 2. Masseter- elevates the mandible 3. External/Lateral Pterygoid- positions the mandible and moves the jaw laterally. It depresses the mandible 4. Internal/Medial Pterygoid- elevates the mandible.. MUSCLES OF MASTICATION The muscles of mastication are responsible for the movement of the jaw during chewing. These muscles work together to coordinate the complex motions required for effective chewing and grinding of food. Functions of Muscles of Mastication The muscles of mastication perform several functions, including: - Initiating and controlling the movement of the mandible during chewing. - Maintaining the stability and alignment of the temporomandibular joint (TMJ). - Providing the necessary force for effective mastication and grinding of food. - Assisting in the proper positioning and alignment of the teeth for optimal occlusion (bite). - Contributing to the production of speech sounds and facial expressions. Functional Movement III. TEMPORO-MANDIBULAR JOINT Main Components of TMJ 1. Mandibular Condyles 2. Articular surface of the mandibular bone 3. Capsule 4. Articular disc 5. Ligaments 6. Lateral Pterygoid. TEMPOROMANDIBULAR JOINT (TMJ) The temporomandibular joint (TMJ) is the joint that connects the mandible to the skull. It allows for the movement of the jaw, including opening and closing of the mouth, as well as side-to-side and forward-backward movements. Features of TMJ □ Left and right joints work in harmony. □ Articular disc separates upper and lower compartments. □ The upper compartment is for the transitory, gliding movement. □ The lower compartment is for rotary or opening movement. □ Covered with avascular fibrocartilage. IV. Dentition TEETH Teeth are hard structures located in the mouth and serve various functions in the digestive process. They are classified into different types based on their shape and function, including: INCISOR Incisors: Sharp-edged teeth at the front of the CANINE mouth used for cutting and biting. Canines: Pointed teeth next to the incisors, used for tearing and gripping food. Premolars: Broad teeth with cusps, involved in chewing and grinding. PREMOLAR Molars: Large, flat teeth at the back of the mouth, responsible for crushing and grinding MOLAR food. V. Supporting Structures Periodontium 1. GINGIVA 2. PERIODONTAL LIGAMENT 3. CEMENTUM 4. ALVEOLAR BONE VI. Limiting structures Outer limiting structures- cheeks, lips Inner limiting structure- tongue  Tongue The tongue is a muscular organ located in the oral cavity and is essential for various functions, including taste perception, swallowing, and speech production. It is composed of muscles and covered with taste buds that allow for the perception of different tastes, such as sweet, sour, salty, bitter, and umami. The movements of the tongue aid in chewing and forming food into a bolus for swallowing, as well as shaping sounds for speech. Tonsils The tonsils are part of the lymphatic system and are located at the back of the throat. They play a role in the body's immune response by trapping and filtering harmful bacteria and viruses that enter the body through the mouth and nose. The tonsils are part of the body's defense mechanism against infections. VII. Saliva/ Salivary Gland Saliva: An aqueous solution which moistens the oral cavity. The major salivary glands are the ff: ◼ Parotid gland - Stensen’s duct ◼ Submandibular gland - Wharton’s duct ◼ Sublingual gland - Bartholin’s duct and the duct of Rivinus VIII Neural □ A communication network that transmits information by electrical signal in and out of the CNS. □ Trigeminal nerve is the main nerve supply of the oral cavity. Neural System of the Oral Cavity The oral cavity is innervated by a complex neural system that includes sensory and motor components. The sensory nerves provide feedback regarding touch, temperature, and taste sensations, while the motor nerves control the movements of the muscles involved in chewing, swallowing, and speech. The main nerve involved in oral sensation and motor control is the trigeminal nerve (cranial nerve V). Other cranial nerves, such as the facial nerve (cranial nerve VII) and glossopharyngeal nerve (cranial nerve IX), also contribute to the neural innervation of the oral cavity. IX. Blood and Lymph Nodes  Blood and Lymph Nodes The oral cavity is supplied with blood vessels and contains lymph nodes that play important roles in maintaining oral health and immune function. The blood vessels deliver oxygen and nutrients to the oral tissues, while the lymph nodes filter and help eliminate toxins, bacteria, and other harmful substances. Proper blood circulation and lymphatic drainage are essential for the overall health and function of the oral cavity.