Oral Physiology and Occlusion Lecture Notes (Stomatognathic System) PDF

PRDM 129 | ORAL PHYSIOLOGY AND OCCLUSION MODULE: 1st Topic for Prelims LESSON: Stomatognathic System 1st SEMESTER | S.Y. 2024-2025 Lecture notes typewritten by: Rhein Fen...

PRDM 129 | ORAL PHYSIOLOGY AND OCCLUSION MODULE: 1st Topic for Prelims LESSON: Stomatognathic System 1st SEMESTER | S.Y. 2024-2025 Lecture notes typewritten by: Rhein Feniza STOMATOGNATHIC SYSTEM ORAL CAVITY TERMINILOGIES Physiology Is the science which deals with the study of normal tissue functions of a normal living body. General Physiology Deals with the study of basic activities of living organisms as a whole, emphasizing on fucntion and dynmaic changes occuring whithin cells, tissues and blood vessels. Oral Physiology A branch of General Physiology which focuses on the functions of the different parts in the oral cavity as well as its associated strcutres. It deals with the Masticatory Apparatus (All structures & organs involved in mastication) Stomatognathic Is a system that comprises of a highly coordinated System structure comprising the human masticatory apparatus. Capable of acting as a single unit for the process of: 1. Mastication 2. Deglutition Is the first portion of the alimentary canal or digestive tract. 3. Phonation Boundaries: 4. Respiration 1. Anteriorly – Lips 5. Other behavioral characteristics or 2. Laterally – Cheeks activities 3. Superiorly – Hard & Soft Palate Group of structures that comprises the 4. Inferiorly – Floor of the Mouth & Tongue Stomatognathic System: 1. Dental Group DIVISIONS OF THE ORAL CAVITY 2. Osseous Group Vestibule Smaller, outer portion 3. Receptor Group Boundaries: 4. Muscular Group 1. Antero-laterally – Lips & cheeks 5. Salivary Glands 2. Postero-medially – Gums & teeth 6. Organs of the Digestive System 3. Superior & Inferiorly – Mucous membrane from the 7. Organs of the Respiratory System lips & cheeks to the gums Oral Cavity Larger, inner portion DEVELOPMENT OF THE ORAL CAVITY Proper Boundaries: 1. Antero-laterally – Alveolar arches with their teeth Oral stomodeum – Is the primitive oral cavity that begins to develop at 2. Superiorly – Hard & soft palate 3 ½ weeks of fetal life. 3. Inferiorly – Tongue & mucous membrane from the side of the tongue to the gums PARTS OF THE ORAL CAVITY Lips Two mobile folds that encircle the rima oris  Rima / Orbicularis Oris – Sphincter muscle of the mouth Covered by skin on its external surface and mucous membrane on its internal surface. Parts: 1. Angle of the mouth – Points where the upper and lower lips meet at the sides. 2. Naso-labial groove – From the side of the nose to the angle of the mouth. 3. Mento-labial groove – Between the chin and lower lip. 4. Philtrum – From the inferior boarder of the nose to the upper lip. 5. Frenulum of the upper and lower lips – Vertical It is lined with an ectoderm and unites with the endoderm to form the mucous folds found on the internal surface of the lips buccopharyngeal membrane. connecting them to the gums. At about 27 days, this membrane ruptures and the stomodeum establishes a connection with the foregut (future digestive tract). At 6 weeks old, the first sign of tooth development is seen. Philtrum Naso-labial Groove The oral ectoderm will give rise to the oral epithelium that runs along the outline of the future dental arches, which is called the DENTAL LAMINA (invagination that forms 2 thicker bands; vestibular lamina & dental ≈ lamina). ≈ Frenulum Simultaneous with the differentiation of the dental lamina, there arises of the round or ovoid swellings at 10 different points in each jaw, upper and lower corresponding to the future position of the deciduous dentition (TOOTH lips BUDS). Mento-labial groove Dental Lamina → Tooth Bud Angle of the mouth ≈ o Enamel Organ – enamel o Dental Papilla – Detin & Pulp o Dental Sac – Cementum, periodontal ligament & alveolar bone pg. 1  Composed of the following layers: HARD PALATE 1. Skin Formed by the palatine processes of the maxilla and the horizontal plates of the palatine bones. 2. Superficial Fascia The surface is covered by the mucous membrane and periosteum 3. Orbicularis Oris Muscle The inferior surface is thicker and its posterior part contain the 4. Submucous Layer blood vessels, nerves and mucous glands. 5. Mucous Membrane Presents the following: 1. Median Raphe – Longitudinal ridge extending from the uvula to the incisive papilla. 2. Incisive Papilla – Small projection of the mucous membrane which lies behind the central incisor indicating the location of the opening of the incisive foramen. It forms the anterior limit of the median raphe. (Clinical significance: Site of puncture for nasopalatine block injection) 3. Transverse Palatine Ridges or Rugae – Is about 3 to 4 distinct elevations crossing the anterior part of the palate. 4. Fovea Palatinae – Constant pits found on the posterior end of the palate, near the midline, that are formed by a coalescence of several mucous gland ducts. (Clinical significance: These pits are close to the vibrating line which Supplied by the following makes them an ideal guide for the location of the posterior o Nerve: border of the denture.) Incisive Papilla 1. Infra-orbital Nerve – From the maxillary nerve ≈ Median Raphe Transverse Palatine and supplies the upper lip 2. Mental Nerve – Form the mandibular nerve and Ridges or Rugae supplies the lower lip ≈ Fovea Palatinae ≈ SOFT PALATE A soft, flexible mass attached to the posterior end of the hard palate. Composed of folds of mucous membrane. Presents the following: 1. Uvula – A conical process on the midline of the posterior border of the soft palate. 2. Palatine Arches of Velum – Free margin of the soft palate extending laterally from the uvula that splits as they approach the lateral walls. The split portion forms the pillars of the soft o Blood: palate. 1. Superior Labial Artery 3. Palatoglossal Arch – Anterior pillar of the fauces or anterior 2. Inferior Labial Artery palatine arch, encloses the palatoglossal muscle. 4. Palatopharyngeal Arch – Larger, posterior pillar of the fauces or posterior palatine arch, encloses the palate-pharyngeal muscle. 5. Isthmus of the Fauces or Tonsillar Sinus – An interval between the anterior and posterior pillars. It is triangular in shape and encloses the palatine tonsils. 6. Isthmus of the Pharynx - Interval between the free margin of the soft palate and the posterior pharyngeal wall separating the nasopharynx from the lower pharynx. Cheeks Forms the lateral boundary of the vestibule of the mouth. Buccinator muscle is the major muscle that makes up the cheeks. Composed of the following: 1. Skin 2. Superficial Fascia 3. Buccopharyngeal Fascia 4. Buccinator Muscle 5. Submucous Layers 6. Mucous Membrane Palate Forms the roof of the mouth separating the nasal cavity and the nasopharynx from the buccal cavity. Divided into 2 parts: 1. Hard palate – Larger, anterior 2/3 2. Soft Palate – Smaller, posterior 1/3 pg. 2  Consists of the following: Floor of Formed chiefly by the mylohyoid muscle and other 1. Palatal Aponeurosis the structures which lie beneath the 2 halves of the body of 2. Mucous Glands Mouth the mandible. 3. Muscles Presents the following: o Levator Palatini Muscles 1. Frenulum Linguae or Lingual Frenum – Median fold o Tensor Palatini Muscles of mucous membrane extending from the floor of o Palatoglossus Muscle the mouth to the inferior surface of the tongue. o Palatopharyngeal Muscle 2. Sublingual Fold – Seen on the side of the tongue o Uvulae Muscle where the ducts of the sublingual salivary gland is located. 3. Sublingual Papilla – Slight elevation on the anterior end of the sublingual fold indicating the opening of the submandibular ducts. 4. Fimbriated Fold – Fold of mucous membrane lying lateral to the frenulum. Supplied by the following: o Nerve: 1. Vagus Nerve 2. Accessory Nerve 3. Mandibular Nerve 4. Glossopharyngeal Nerve Tongue A movable mass of muscle covered with mucous membrane lying on the floor of the mouth and associated with the functions of taste, chewing, swallowing and speaking. Parts: 1. Root – Lower, posterior portion through which the extrinsic muscles, blood vessels and nerves are connected with the organ. 2. Body – Anterior, larger portion made up of interlacing skeletal muscles. 3. Margins – Lateral sides of the organ, free and blunt in relation to the gums and teeth. 4. Tip/Apex – Pointed and free anterior end, directed anteriorly against the incisor teeth. It is blunt and rounded when the tongue is at rest. 5. Dorsum Linguae – Slight convex anteroposteriorly. It is divided by V-Shaped groove called Sulcus Terminalis into: o Anterior 2/3 – Where lingual papilla are found o Posterior 1/3 – Where lingual tonsils are located o Blood: 1. Greater Palatine Artery 2. Lesser Palatine Artery Apex pg. 3  Lingual papillae – Consists of 3 kinds: o Intrinsic Muscles – Are confined within the 1. Vallate/Circumvallate Papilla – 10 to 12 per human substance of the tongue and capable only of tongue changing the shape. 2. Fungiform Papilla – Scattered in between filiform 1. Inferior Longitudinal papilla 2. Superior Longitudinal 3. Filiform Papilla – Most numerous and distributed in 3. Transverse rows 4. Vertical ▪ Nerve Supply of the Intrinsic Muscles: 1. Hypoglossal Nerve 2. Lingual Nerve 3. Glossopharyngeal 4. Chorda Tympani ▪ Blood Supply of the Intrinsic Muscles: 1. Lingual Artery 2. Tonsillar Artery Muscles of the tongue: o Extrinsic Muscles – Originate from the outside of the tongue. These functions to change the position as well as the shape of the tongue. 1. Genioglossus 2. Hyoglossus 3. Styloglossus 4. Palatoglossus 5. Chondroglossus ▪ Nerve Supply of the Extrinsic Muscles: 1. Hypoglossal Nerve 2. Spinal Accessory Nerve pg. 4  PRDM 129 | ORAL PHYSIOLOGY AND OCCLUSION MODULE: 2nd Topic for Prelims LESSON: FUNCTIONS OF STOMATOGNATHIC SYSTEM 1st SEMESTER | S.Y. 2024-2025 Lecture notes typewritten by: Rhein Feniza FUNCTIONS OF STOMATOGNATHIC SYSTEM 3. Esophageal – Involuntary transport phase whereby the food passes along the esophagus through a relaxed lower esophageal MASTICATION Phases 1. Moulding of the food and saliva into a ball or bolus 2. Forming of the bolus back in the mouth to contact the Purpose 1. Physiological transformation of food posterior pharyngeal wall and palatoglossal arches 2. Enhance growth and development of dento-alveolar structures Regurgitation through stimulation Vomiting 3. Stimulates salivary flow Characteristics 1. Lips are fused and appears stiff 4. There is volatization of food to increase appetite of infantile 2. Tongue is abnormally large and it is caught between the 5. Protection of the individual from undesirable food components swallowing maxillary and mandibular gum pads 6. Help further develop or allow jaw bone to grow 3. There is no harmonious relationship between in maxilla and Mechanical 1. Voluntary the mandible (mandible is at its most posterior position) Process of 2. Involuntary 4. Absence of normal seal Chewing 5. There is no harmonious relationship between the cranial Phases of 1. Opening and facial structure Chewing Jaw opening phase usual opening (10-15mm) Characteristics 1. Presence if normal seal Cycle It is accomplished by the action of the digastric and of adult 2. Presence of normal occlusion mylohyoid muscle with the help of gravity swallowing: 3. Tongue is inside the oral cavity 2. Closing 4. There is normal antero-posterior relationship between the Jaw closing phase maxilla and the mandible 3. Occlusal 5. There is harmonious relationship between the cranial and Slow jaw closing phase the facial structure Food is crushed Conditions o Dysphagia Accomplished by the masseter internal pterygoid and associated in o Odynophagia temporalis muscle swallowing o Aphagia Muscle undergo isotonic contraction or relaxation o Abnormal growth on the esophagus Gradual change Stages of 1. Incisal SPEECH Mastication Characteristics: o Knife-like edge of incisors Normal 1. Afferent mechanism o Monorooted condition which is sufficient for their development 2. Association areas-involves the: simple function of speech is Seat of learning and memory o Incisors are supported by the intermaxillary sutures affected by the Seat if habits and condition and the symphysis menti following 3. Efferent mechanism o Lips are in contact and there is the presence of oral 4 Process 1. Respiration seal 2. Phonation o Teeth comes in full contact 3. Resonance 2. Direct Crushing Resounding gravity Characteristics: The prolongation and intensification of sound o Includes cuspids and bicuspids o Dullness o Presence of a more inclined plane or more surface o Flatness contact 4. Articulation o Working side is where the food is and the other side will be the balancing side Act of speaking 3. Mortar and Pestle This involves a complex coordinating movement of the Characteristics: following: o Normal oral seal produced by the upper and lower lip o Muscles of the lips o Normal occlusion is present o Cheeks o Normal antero-posterior relationship of the maxilla o Palate and mandible o Tongue o Presence of symmetrical phase o Posterior laryngeal wall o Tongue is kept within the oral cavity o There is harmonious relationship between the cranial RESPIRATION and facial structure o Mastication is soundless Kinds 1. External – between blood and environment “Duration of chewing does not affect the amount” 2. Internal – Between blood and the cell Stages 1. Inspiration – intake of oxygen 2. Expiration DEGLUTITION Characteristics: o Decrease in size of the thoracic cavity Purpose Transport of material from mouth to esophagus o Ribs moves downward while the diaphragm o Adult – deglutition moves upwards in a relax stage o Infant – suckling and sucking Characteristics 1. Increase in size of thoracic cavity Characteristics 1. Anterior of tongue is retracted 2. There is backwards movement of thoracic cavity 2. Hyoid bone is elevated 3. Spinal column moves backwards and diaphragm moves 3. Mastication stops downward 4. Respiration reflex stops Causes of 1. Colds/Influenza 5. Back portion of the tongue is elevated and retracted against mouth 2. Obstruction of the nasal cavity the palate breathing 3. Deviated nasal septum (cleft palate) Mechanical 1. Voluntary – initial act is voluntary Characteristics 1. Presence of normal seal Process 2. Involuntary – actions becomes involuntary when food of normal 2. Normal atmospheric pressure comes in contact with the oropharynx respiration 3. Normal TMJ Stages 1. Oral – Is a voluntary act where you elevate the anterior 4. Normal occlusion aspect of the tongue passing against the palate pushing 5. Normal antero-posterior relationship of the maxilla and the 2. Pharyngeal – Begins as the bolus of the food is carried mandible between the tongue, the soft palate, the constrictor wall 6. Tongue is kept within the oral cavity and the epiglottis 7. Establishment of physiologic rest position pg. 5  PRDM 129 | ORAL PHYSIOLOGY AND OCCLUSION MODULE: 3rd Topic for Prelims LESSON: Physiology of the Teeth 1st SEMESTER | S.Y. 2024-2025 Lecture notes typewritten by: Rhein Feniza PHYSIOLOGY OF THE TEETH Protective Functional 1. Proximal contact area (PCA) Forms of the Tooth Crown Teeth – The prominent structure in the oral cavity. o Major Functions in Life of the Human Teeth: 1. Incise and reduce food material 2. Help sustain themselves in the dental arches Importance of Proper Contact Relation o Important Values Between the Teeth: 1. Physically attractive o It serves to keep food from packing in 2. Good diction and correct speech between the teeth. 3. Psychologically o It helps to stabilize the dental arches by the combines anchorage of all the teeth in either arch, if in positive contact with MORPHOLOGY & PHYSIOLOGY OF THE TOOTH each other. Geometric concept of 1. Triangle The third molars are prevented from drifting crown outlines distally where there is no contacting tooth due to: o The angulation of their occlusal surface with their roots o The angle of the direction of the occlusal forces in their favor. PCA Can Be Observed From Two Aspects: o Labial/Buccal Aspects o Incisal/Occlusal Aspects 2. Interproximal Spaces 2. Trapezoid Longest uneven side towards the occlusal or incisal surface Shortest uneven side towards the occlusal: o Mesial & distal aspects of all maxillary posterior teeth 3. Rhomboid Crown & Roof Forms 1. Crown according to their Covered with enamel 3. Embrasures (spillways) Function Kinds of Embrasures: o Labial or buccal and lingual interproximal o Incisal or occlusal Purposes: o It makes a spillway for the escape of food during mastication. o It prevents food from being forces through the contact area. 4. Facial and Lingual Contours at the Cervical Thirds (Cervical Ridges) Approximately 0.5mm is the normal curvature from the CEJ to the crest of the contour. Physiologic Importance: o Holds the gingiva under definite tension o Protects the gingival margins by deflecting food material away from the margins during mastication Effects of the Absence or Minimal Curvature:  Incisal ridge/edge – Central and lateral o Gingival tissue may be driven apically incisor resulting to gum recession and possible  Single cusp – Canines and cuspids pathologic changes.  Two cusp – Premolars and bicuspids Effect of Too Much Curvature  Three cusp – Molars o Gingiva is protected too much and loses 2. Root tissue “tone” under the exaggerated Covered with cementum contour.  Single rooted – Incisors, canines, and o Food material and debris will be packed premolars (Max. 2nd PM and Mand. 1st around the gingiva. and 2nd PM) o Stagnation of foreign material leads to  Birooted – 1st premolar maxillary chronic inflammation of the gingiva. Multirooted – Maxillary molars 5. Curvatures of the Cervical Lines (CEJ) pg. 6