1. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 1 Chapter 5 Embryology

2. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 2 Terms PRENATAL Postnatal

3. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 3 3 stages of Pregnancy Zygote (2 weeks) Embryo (2-8 weeks) Fetus ( 9 weeks – birth/ 9 months)

4. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 4 Embryology Primitive facial development –Three primary embryonic layers Ectoderm Developing brain Developing nervous system ENAMEL, gingiva Mesoderm Developing heart, and internal organs DENTIN< CEMENTUM< PULP Endoderm Developing digestive system and glandular organs

5. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 5 Zygote& Embryo stage Zygote- proliferate Embryo- differentiate ( 3 stages) 1. Cytodifferentiate (cells) 2. Histodifferentiate ( tissues) 3. Morphodifferentiate ( form/shape)

6. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 6 Embryonic Facial Process Embryo Child Adult Frontonasal process Medial nasal Mandibular process Frontonasal process Nasolacrimal groove Medial nasal (maxillary) Philtrum Upper lip Mandibular process Labial commisures Frontonasal process Maxillary process Labial commissures Philtrum Mandibular process

7. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 7 FACE Development of the face begins 4 th week Frontonasal process forms: Forehead, eyes, nose, philtrum Middle of face forms –Called:Maxillary process –Forms: cheeks, upper lip, soft palate, zygoma

8. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 8 Development of the face Mandibular process forms mandible, lower lip, lower face Stomedeum or primitive mouth

9. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 9 Development of the face Face continues to develop until 12 th week Maxillary processes on each side fuse at the: Labial Commissures Frontonasal process fuses with the: Maxillary Process

10. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 10 Embryo to Fetus

11. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 11 Week 10-11

12. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 12 Development of the palate Primary palate develops by 6 th week –Anterior portion forms with 4 incisors Palatine process develops by 9 th week –When primary and premaxilla join –Forms in H shape

13. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 13 Development of the palate Secondary palate develops by 12th week –Two halves of palate fuse together –Hard palate –Remaining teeth –Soft palate & uvula

14. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 14 CLEFT Improper formation of Palate _CLEFT_____lip and palate Failure of fusion of the palate or lip and nasal process can occur between weeks _6th__ and _12th___ of development

15. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 15 Cleft Lip When maxillary processes fail to fuse with the medial nasal process Unilateral – Bilateral – Occurs about one in 1000 births

16. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 16 Cleft Palate Failure of the palatal shelves to fuse with the primary palate Occurs about one in 2500 births Cleft palate more common in GIRLS Cleft lip more common in Boys

17. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 17 Unilateral cleft lip, primary palate, and alveolar process Bilateral cleft of the secondary palate Cleft uvula Cleft lip; unilateral versus bilateral Cleft palate Development Disturbances Philtrum Lip Incisive papillae Hard palate Soft palate Cleft uvula Nasal cavity Nasal septum Philtrum Lip Primary palate Alveolar process Secondary palate

18. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 18 Bilateral cleft of the lip, alveolar process, and primary palate Bilateral cleft of the lip, alveolar process, and primary and secondary palate Cleft lip; unilateral versus bilateral Cleft palate Development Disturbances Philtrum Lip Primary palate Alveolar process Secondary palate

19. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 19 Cleft Lip & Palate

20. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 20 Cleft

21. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 21 Developmental disturbances ANOMALY – Deviation –Disturbances can occur during:prenatal Genetic factors – –Often affect development of teeth –Can affect growth of bone

22. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 22 Inherited factors Inheritance will affect tissues such as TEETH Only things inherited are: –A. Size –B. Shape –C. Color –D. Number

23. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 23 Inherited factors Person could inherit: lg teeth, sm bone –Results could be: Person could inherit: sm teeth, lg bone –Results could be:

24. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 24 Inherit Mismatched jaw sizes

25. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 25 Environmental factors Mother’s body provides: environment for fetus Changes can affect: diet, infection, medication

26. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 26 Fetal Alcohol

27. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 27 Syphillis

28. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 28 The End