Dental Anatomy and Physiology for Clinical Dental Technicians. with Marnie Hayward

Transcription

1 Dental Anatomy and Physiology for Clinical Dental Technicians with Marnie Hayward

2 Salivary glands Parotid Submandibular Sublingual

3 Salivary glands position

4 Parotid glands Lie below ear and behind angle of mandible Produce thin serous saliva which flows into mouth via Stensons ducts which lie opposite maxillary 2 nd molars

5 Submandibular glands Lie against inside of mandible close to the molars and premolars Produce a muco-serous saliva which flows into mouth via Whartons s ducts

6 Sublingual glands Lie further forward than submandibular glands, either side of lingual frenum Produce thick mucous saliva which flows into mouth through ducts called ducts of Rivinus

7 In your learning sets... List the functions of saliva

8 Functions of saliva Aids Digestion Bolus formation Lubrication Cleansing contains enzyme ptyalin (amylase) which begins digestion of starches softens food making it easier to swallow keeps mouth moist, aiding clear speech washes and cleans the mouth

9 Functions of saliva Buffer stabilises changes in acid/alkali balance Solvent Antibacterial action helps to dissolve solids before they can be tasted To protect oral cavity

10 The Tongue Ventral surface Dorsal surface

11 The Tongue Highly muscular structure Covered by mucous membrane Lies on mylohyoid muscle in floor of mouth Attached to floor by thin fold of mucous membrane called the lingual frenulum Covered with small fungiform and filiform papillae on upper (dorsal) surface taste buds 8-12 larger vallate papillae form inverted V shape towards base

12 Functions of the Tongue Mastication (chewing) Deglutition (swallowing) Speech Taste

13 Papillae (taste buds) and taste areas?

14 Taste detection Tongue can detect 5 basic tastes Sweet Sour Salt Bitter Umami (savoury) No evidence to suggest different areas detect different tastes

15 Extrinsic muscles of the tongue Muscle From Function Genioglossus Mandible Protudes tongue, depresses centre Hyoglossus Hyoid bone Depresses tongue Styloglossus Styloid process Elevates and retracts tongue Palatoglossus Soft palate Depresses soft palate Elevates back of tongue

16 Intrinsic muscles of the tongue 4 paired muscles Originate and insert within tongue Lengthen and shorten Curl and uncurl apex and edges Flatten and round edges

17 Oral cavity and beyond

18 The Oral Cavity

19 Cross section of molar

20 Enamel Protective outer covering of the crown Hardest substance in the body Doesn t contain any nerves/blood vessels Insensitive to pain Cannot undergo repair - damage caused by decay/injury is permanent Microscopically, consists of long solid rods - prisms

21 Microscopic appearance of enamel surface and dentine

22 Dentine Forms interior of crown and root Highly sensitive to pain Protected from painful stimuli by enamel of crown and cementum of root Contains dentinal tubules which make it slightly elastic like a shock absorber Softer than enamel, less mineralised

23 Cementum Calcified substance covering root of tooth Formed by cementoblasts Anchors tooth to bone via periodontal ligament

24 Cementum under the microscope

25 Pulp Purely soft tissue unlike enamel, dentine and cementum Nerves and blood vessels enter root apex through apical foramen and pass up through root to pulp chamber Contains odontoblasts (dentine forming cells) in outermost layer, next to dentine Odontoblasts contain dentinal fibrils which pass into dentine through tubules Secondary dentine is produce slowly throughout life Reparative dentine is produced quickly in response to damage

26 Dental pulp Contains odontoblasts (dentine forming cells) in outermost layer, next to dentine Odontoblasts contain dentinal fibrils which pass into dentine through tubules

27 Supporting structures - bone The alveolar process is a ridge of bone containing the tooth sockets Jaws bones contain dense outer layer (compact bone) and softer interior (spongy/cancellous bone) Lamina dura is compact bone lining of tooth socket a well defined lamina dura is an indicator of good periodontal health

28 Normal lamina dura Thickening of lamina dura due to periodontal disease

29 Supporting structures - gingiva Firmly attached to underlying alveolar bone Fits around neck of each tooth like tight cuff Gingival crevice - shallow crevice present between tooth surface/gum margin Interdental papilla - triangular mound of gum in between teeth

30 Gingival margin Gingival crevice Free gingiva Periodontal ligament Attached gingiva Alveolar bone

31 Interdental papilla

32 Supporting structures periodontal ligament Soft fibrous tissue which attaches each tooth to its socket (cementum to lamina dura) Acts as a shock absorber Contains nerves and blood vessels Bundles of fibres also attach gingival margin to tooth/alveolar bone and each tooth to its neighbour

33 Tooth and supporting structures

34 Now in your learning sets, label the diagram of the oral cavity...