1. Why study Diet? Utility for model building? Food provides energy necessary to sustain life and allow for reproduction Main activity of most animals’ lives Major component of natural selection: “obtain food and keep from becoming food”

2. Why study teeth? Utility for model building? Indicate foods consumed Indicate size & behavior Well preserved in the fossil record Growth & development patterns Sexual dimorphism characteristics Non-dietary indicators

3. Tooth Types

4. Human Dentition Tooth Types

5. Roles of the teeth Differential use in heterodont dentition Incisors & canines -- ingestion, get the food into the mouth seizing, stripping, squashing, puncturing Incisors & canines -- ingestion, get the food into the mouth seizing, stripping, squashing, puncturing Premolars & molars -- preparation of food for digestion food is chopped up to increase surface area molars are a series of cutting blades and crushing basin Premolars & molars -- preparation of food for digestion food is chopped up to increase surface area molars are a series of cutting blades and crushing basin

6. Extant vs Extinct Data collection from the living primates

7. Diagnostic features Incisors & canines Features of the skull used to determine dietary category Molars & premolars Cusps & crests Enamel thickness Massiter & temporalis muscles Body size

8. Anterior Dentition Get food in the mouth Grooming Scraping ~~~~~~~~~~~~~~~~~~~~ Get food in the mouth Grooming Scraping ~~~~~~~~~~~~~~~~~~~~ Incisors & Canines Large incisors indicate frugivore Small incisors = carnivore or insectivore Large incisors indicate frugivore Small incisors = carnivore or insectivore

9. Incisors

10. Canines

11. Premolars & Molars Posterior Dentition Folivores = low or high Insectivores = tall, pointed Carnivores = tall, pointed Frugivores = low, rounded Omnivore = low, rounded

12. Premolars & Molars

14. Cusps & Crests Molar & premolar morphology cusp crest

15. Enamel thickness Thickness of the hard mineral surface covering the teeth

16. Dental Attrition Enamel wear

17. Muscles of mastication

18. Body size Diet dictates primate body size Body-size tends to correlate w/ dietary regime Body-size tends to correlate w/ dietary regime Folivore = largest Insectivore = smallest Frugivore = medium to large

19. Dietary strategies Folivore - plants Categories of Diet for the Primates Frugivore - fruit Carnivore - meat Insectivore - insects Omnivore - mixed

20. Age Changes Subadult Dentition

21. Human Chewing Anatomy of the TMJ temporalis massiter 1. Temporal bone 2. Mandibular condyle

22. Human Chewing Movement of the TMJ held in place by a sheath of tendon and muscles glides on cartilage Bursa helps absorb some forces Literal double joint held in place by a sheath of tendon and muscles glides on cartilage Bursa helps absorb some forces Literal double joint

23. Human Chewing Motions of the Mandible …but subject to very complex movements and forces.

24. Human Chewing “Disarticulation” of the TMJ

25. Human Chewing Nerves & Blood Vessels around TMJ

26. Human Chewing Disorders of the TMJ & Associated Structures Developmental Condylar Hyperplasia Hyperplasia Agensis Infectious Spread Tuberculosis Syphillis Gonorrhea Staphylococcal Infection Streptococcal Infection Inflammatory rheumatoid arthritis Psoriatic arthritis Reiter’s syndrome Systemic lupus erthematosis Familial Mediterranean fever Degenerative osteoporosis Traumatic Condylar Fracture Ankylosis Internal rearrangement Metabolic Gout Pseudogout TMJ Pain Dysfunction Neoplastic Benign Tumors Fibro-Osseous Disorders Fibrous dysplasia Paget’s disease Luxation & Subluxation

27. Human Chewing Clinical Aspects Burt Reynolds “In” malady drew attention to the extent of the disorder

28. Human Chewing Treatments

29. Human Chewing Measuring Mandibular Angle

30. Human Chewing Molar & Incisal Chewing

31. Human Chewing Hylander’s Lever Action Model Trouble w/TMJ: Chew on the same side as pain Trouble w/TMJ: Chew on the same side as pain Trouble w/molar: Chew on the opposite side Trouble w/molar: Chew on the opposite side

32. The Nubians

33. Human Chewing condyle pathology

34. fossa pathologies

35. Human Chewing Categories Studied Age Sex Complete Socket Resorption Active Pathologies Dental Attrition Age Sex Complete Socket Resorption Active Pathologies Dental Attrition

36. Human Chewing Age Changes in the Mandible Lateral View Dorsal View

37. Human Chewing Age & Sex Relationships 35.12 AGE SEX male female TMJ PATHOLOGY - + 34.47 26.40 70.60 47.60 52.40

38. Human Chewing Complete Socket Resorption

39. Human Chewing Complete Socket Resorption

40. caries partial socket resorption abcess

41. Human Chewing Dental Caries & Abcesses 0.79 ABCESS CARIES TMJ PATHOLOGY + - 0.24 0.71 2.88 1.39 2.27 PARTIAL RESORPTION

42. Human Chewing Dental Attrition tooth wear

43. Human Chewing Results Significantly more females affected compared to males Greater wear found on the same side as TMJ damage Greater wear found on side opposite carious lesions Trends similar to clinical findings