Growth and Development of Craniofacial Complex
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The document discusses craniofacial growth and development. It describes how the maxilla and mandible grow, including through apposition of bone at sutures for the maxilla and condylar growth and surface remodeling for the mandible. It also discusses assessing growth through hand-wrist radiographs and cephalograms, and the importance of understanding growth for orthodontic treatment planning. Key topics covered include intramembranous vs. endochondrial bone formation, sites of skull growth, growth of the upper face and mandible, and how growth is evaluated.
Growth and Development of Craniofacial Complex
- 1. Fourth Lecture Growth and Development of The Craniofacial Complex
- 2. Growth of the Face Growth of the upper face (Nasomaxillary complex): The Nasomaxillary complex is connected to the cranial base by means of six pairs of sutures. These are: 1. Frontomaxillary 2. Frontonasal 3. Zygomatico-frontal 4. Zygomatico-temporal 5. Pterygo-palatine 6. Zygomatico-maxillary May 22, 2012 Dr. Ahmed Basyouni 2
- 3. Growth of the upper face Intramembranous Ossification: By apposition of bone at the sutures that connect the Mx to the cranium and cranial base. By surface remodeling. May 22, 2012 Dr. Ahmed Basyouni 3
- 4. Growth of the Maxilla Remodeling of the palatal vault moves it in the same direction as it is being translated Bone is removed from the floor of the nose and added to the roof of the mouth May 22, 2012 Dr. Ahmed Basyouni 4
- 5. Growth of the Maxilla Growth of the surrounding soft tissues (eyeballs) translates the maxilla downward and forward, opening spaces in the sutures where bone is added. May 22, 2012 Dr. Ahmed Basyouni 5
- 6. Growth of the Maxilla Midpalatal suture is opened until teenage years. Apposition of bone in the molar area accounts for space for the third molars. May 22, 2012 Dr. Ahmed Basyouni 6
- 7. Growth of the Maxilla Summary: Growth of the maxilla occurs in 2 ways: • By apposition of bone in the sutures that connect the maxilla to the cranial base • By surface remodeling. May 22, 2012 Dr. Ahmed Basyouni 7
- 8. Growth of the Face Growth of the Mandible: The mandible is mixed endochondrial and intramembranous bone. It consists of three major parts: the body, the alveolar process and the two rami. Ramus Ramus Alveolar process Body May 22, 2012 Dr. Ahmed Basyouni 8
- 9. Growth of the Face Growth of the Mandible: At birth the mandible resembles a curved bar containing the tooth buds. The condyle, coronoid, angular (gonial), and alveolar processes are poorly developed. The mandible is formed of two halves joined at the mental symphysis. Postnatal closure of the symphysis occurs during the first year of life. May 22, 2012 Dr. Ahmed Basyouni 9
- 10. Growth of the Mandible Remodeling is done by resorption in the anterior part of the ramus and deposition in the posterior part of the ramus May 22, 2012 Dr. Ahmed Basyouni 10
- 11. Growth of the Mandible The main sites of mandibular growth: 1. The mandibular condyle: The cartilaginous growth of the condyle is by surface apposition and interstitial growth. Growth direction of the condyle is upwards, backwards, and outwards so the mandible is translated forwards and downwards. May 22, 2012 Dr. Ahmed Basyouni 11
- 12. The main sites of mandibular growth: 2. Surface apposition and remodeling resorption: Surface apposition at the posterior border of the mandible is the main factor in the lengthening of the mandible and decrease in the size of the gonial angle from 170 at birth to 120 degrees in adults. May 22, 2012 Dr. Ahmed Basyouni 12
- 13. The main sites of mandibular growth: 2. Surface apposition and remodeling resorption: Resorption of bone at the anterior border of the ramus takes place and contributes to the lengthening of the alveolar bone posteriorly to accommodate the erupting posterior teeth. May 22, 2012 Dr. Ahmed Basyouni 13
- 14. The main sites of mandibular growth: 2. Surface apposition and remodeling resorption: Generalized surface apposition on the outer surface of the mandible is responsible for increase in its thickness. May 22, 2012 Dr. Ahmed Basyouni 14
- 15. The main sites of mandibular growth: 2. Surface apposition and remodeling resorption: The mental foramen is situated during the early years of life under the mesial cusp of the first deciduous molar, whereas in adults it is situated below and between the roots of the first and second premolars, due to surface apposition of bone. May 22, 2012 Dr. Ahmed Basyouni 15
- 16. Growth of the Mandible Overall growth direction results in a downward and forward displacement with most of growth occurring in the ramus. May 22, 2012 Dr. Ahmed Basyouni 16
- 17. How to assess growth? Hand wrist x-ray: To assess skeletal age by comparing degree of ossification of carpal bones of wrist, metacarpals of hand and phalanges of the fingers to standard atlas of hand-wrist development. Sexual maturity: onset of menarche in girls, voice changes and facial hair in boys. May 22, 2012 Dr. Ahmed Basyouni 17
- 18. How to assess growth? Lateral cephalogram tracings: superimpositions Boy growing normally Black - 10 years Red - 14 years May 22, 2012 Dr. Ahmed Basyouni 18
- 19. Why do we assess growth? To determine optimum time for treatment (growth modification and surgery). To determine the amount of growth left. To determine type of growth )horizontal or vertical). May 22, 2012 Dr. Ahmed Basyouni 19
- 20. The Human Head Shape Brachycephalic • short and wide “Brachy” tends to grow horizontally; Dolichocephalic • tall and narrow “Dolicho” tends to grow vertically. Knowing the general pattern of growth and the expected direction can be helpful in orthodontic diagnosis and treatment planning. May 22, 2012 Dr. Ahmed Basyouni 20
- 21. Facial Profile Convex Retrognathic May 22, 2012 Straight Orthognathic Dr. Ahmed Basyouni Concave Prognathic 21
- 22. Summary of all Definitions: Growth Development Types of bone formation: Intramembranous bone Endochondrial bone Sites of skull growth: May 22, 2012 Dr. Ahmed Basyouni 22
- 23. Summary of all Growth of the head: - Growth of the cranium: Cranial vault. Cranial base. - Growth of the face: Growth of the upper face (nasomaxillary complex). Growth of the mandible. May 22, 2012 Dr. Ahmed Basyouni 23
- 24. Summary of all How to assess growth. Why do we assess growth. Human head shape. May 22, 2012 Dr. Ahmed Basyouni 24
- 25. Who Works With Their Minds are Scientists. Who Works With Their Hearts are Artists. Who Works With Their Hands are Workers. Who Works With All of Them are Orthodontists. May 22, 2012 Dr. Ahmed Basyouni 25