The document summarizes prenatal craniofacial growth and development from the period of the ovum to the period of the fetus. It discusses the formation and ossification of structures like the cranial base, maxilla, mandible and palate. Key points include:
- The cranial base develops from mesenchymal tissue and forms cartilage centers that fuse to form the occipital, temporal and sphenoid bones.
- The maxilla develops from the first brachial arch and maxillary processes. The palate forms from the palatal shelves and separates the nasal cavities.
- The mandible develops from the first brachial arch and forms from intramembranous
This document discusses the evolution and development of the human face. It begins by outlining key theories of evolution, such as Lamarckism, natural selection, and Mendelian inheritance. It then describes the evolution of early human ancestors like Australopithecus and Homo habilis through Homo sapiens. Regarding development, it explains how the face forms from the pharyngeal arches and pouches during embryogenesis, including the formation of structures like the jaw, ears, and thyroid. It provides a high-level overview of the evolution and embryonic development of the human face.
The document discusses the development of the face and palate in humans. It describes how the face develops from structures around the stomatodeum, including the frontonasal process and first pharyngeal arch. The lips, nose, cheeks, eyes, and ears develop through the growth and fusion of these structures between 4-8 weeks. The palate develops from the primary and secondary palate, which grow towards each other and fuse between 6-12 weeks. Possible developmental anomalies that can occur if this process is disrupted include cleft lip, cleft palate, and abnormalities in the size and position of facial features.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Growth & development of face/certified fixed orthodontic courses by India...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Development of the Face, Oral Cavity & Pharyngeal arches2015101
The development of the face occurs mainly between 4-8 weeks of gestation. The lower jaw forms first at 4 weeks, while facial proportions develop between 9 weeks to birth. During this period, the frontonasal, maxillary, and mandibular prominences form and fuse to create the structures of the face. Between 4-12 weeks, the nasal pits form and fuse to create the nasal cavities and septum. The primary palate develops by 6 weeks, and the secondary palate fuses between the lateral palatal processes by 12 weeks to separate the oral and nasal cavities. After birth, further growth of structures like teeth and sinuses contribute to the definitive shape of the face.
Development of face and oral cavity 4 /certified fixed orthodontic courses by...Indian dental academy
The document discusses the embryological development of the face and oral cavity. It describes how the branchial arches and pharyngeal pouches form and give rise to various structures. It explains the development of the primitive mouth and how the facial processes including the nasal placodes form the face. Tooth development occurs in the dental lamina within the maxillary and mandibular processes, progressing through the bud, cap and bell stages to form the tooth germ.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Development of oral cavity and face .ppt by dr. samidha aroraSamidha Arora
The document summarizes the development of the oral cavity and face from the 4th week of embryonic development. It discusses how the frontonasal process, nasal placodes, maxillary processes, and mandibular processes give rise to different structures of the face. It also describes the development of the palate from palatal shelves growing from the maxillary processes that later fuse together.
This document discusses the evolution and development of the human face. It begins by outlining key theories of evolution, such as Lamarckism, natural selection, and Mendelian inheritance. It then describes the evolution of early human ancestors like Australopithecus and Homo habilis through Homo sapiens. Regarding development, it explains how the face forms from the pharyngeal arches and pouches during embryogenesis, including the formation of structures like the jaw, ears, and thyroid. It provides a high-level overview of the evolution and embryonic development of the human face.
The document discusses the development of the face and palate in humans. It describes how the face develops from structures around the stomatodeum, including the frontonasal process and first pharyngeal arch. The lips, nose, cheeks, eyes, and ears develop through the growth and fusion of these structures between 4-8 weeks. The palate develops from the primary and secondary palate, which grow towards each other and fuse between 6-12 weeks. Possible developmental anomalies that can occur if this process is disrupted include cleft lip, cleft palate, and abnormalities in the size and position of facial features.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Growth & development of face/certified fixed orthodontic courses by India...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Development of the Face, Oral Cavity & Pharyngeal arches2015101
The development of the face occurs mainly between 4-8 weeks of gestation. The lower jaw forms first at 4 weeks, while facial proportions develop between 9 weeks to birth. During this period, the frontonasal, maxillary, and mandibular prominences form and fuse to create the structures of the face. Between 4-12 weeks, the nasal pits form and fuse to create the nasal cavities and septum. The primary palate develops by 6 weeks, and the secondary palate fuses between the lateral palatal processes by 12 weeks to separate the oral and nasal cavities. After birth, further growth of structures like teeth and sinuses contribute to the definitive shape of the face.
Development of face and oral cavity 4 /certified fixed orthodontic courses by...Indian dental academy
The document discusses the embryological development of the face and oral cavity. It describes how the branchial arches and pharyngeal pouches form and give rise to various structures. It explains the development of the primitive mouth and how the facial processes including the nasal placodes form the face. Tooth development occurs in the dental lamina within the maxillary and mandibular processes, progressing through the bud, cap and bell stages to form the tooth germ.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Development of oral cavity and face .ppt by dr. samidha aroraSamidha Arora
The document summarizes the development of the oral cavity and face from the 4th week of embryonic development. It discusses how the frontonasal process, nasal placodes, maxillary processes, and mandibular processes give rise to different structures of the face. It also describes the development of the palate from palatal shelves growing from the maxillary processes that later fuse together.
Growth & development of face/certified fixed orthodontic courses by India...Indian dental academy
The document discusses the development and growth of the face from early embryogenesis through adulthood. It describes how the face develops from five prominences surrounding the mouth, including the frontonasal, paired maxillary, and paired mandibular processes. It also discusses the development of structures like the nose, eyes, ears, palate and branchial arches and how anomalies can occur. The growth and anatomy of the face is then covered, addressing topics like muscles, nerves, arteries, growth patterns and theories.
Face develops in humans between 4th – 10th week of intrauterine life.
prenatal growth of the maxilla
DEVELOPMENT OF UPPER LIP
Development of lower lip
Development of nose
hare lip
OBLIQUE FACIAL CLEFT
macrostomia
lateral facial cleft
microstomia
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Development of Face /certified fixed orthodontic courses by Indian dental ac...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
01. pharyngeal arches (3 lectures, march 18)monazain3
The pharyngeal apparatus consists of pharyngeal arches, pouches, grooves, and membranes that contribute to development of the head and neck. By the 4th week of development, 4 pairs of pharyngeal arches are present externally and are separated by pharyngeal grooves. The arches give rise to important structures of the face, neck, and organs through their mesenchymal, cartilaginous, muscular, and nervous components. Derivatives of the pharyngeal arches include bones, muscles, blood vessels, and nerves that form the jaw, tongue, larynx, and other head and neck structures.
1. The cranial end of the embryo folds first due to the rapid growth of the brain, forming the primitive oral cavity and stomatodeum.
2. The face develops from five mesodermal elevations called processes that are augmented by neural crest cells and lined with ectoderm. These include the frontonasal process, two maxillary processes, and two mandibular processes.
3. The frontonasal process forms the forehead and nose. The maxillary processes form parts of the upper lip, cheek, and palate. The mandibular processes merge to form the lower lip and chin.
The head and neck develop from the first four pharyngeal arches and are highly complex structures requiring contributions from all three germ layers. The pharyngeal arches give rise to many structures in the head including bones, muscles and nerves. The face develops from fusion of the frontonasal process and medial and lateral nasal processes between 4-7 weeks. The primary palate arises from the medial nasal process while the secondary palate develops from fusion of the two palatine processes between 7-12 weeks. The tongue develops from the first four pharyngeal arches and the maxilla develops from the dorsal end of the first pharyngeal arch.
This document provides an overview of facial development from fertilization through the formation of facial structures. It discusses the formation and fate of the germ layers and pharyngeal arches, which give rise to facial tissues and structures. Key stages of development discussed include formation of the lens, nose, cheeks, eyes, external ear, and palate. Common anomalies in facial development are also summarized, such as cleft lip and palate.
The document summarizes prenatal and postnatal growth and development of the face. It describes how the face increases in size much more during the prenatal period compared to postnatal growth. It outlines the development of the face from the gestational periods and formation of the primordia. It discusses common anomalies during development and functional therapies. The craniofacial bones undergo remodeling and fusion during childhood with the skull assuming the adult shape by adolescence.
1. The document discusses prenatal facial growth, which can be divided into three periods: the period of the ovum, embryo, and fetus.
2. During the period of the embryo (1-7 weeks), the major development of the facial and cranial regions occurs, including the formation of the branchial arches which give rise to structures of the face, neck, and throat.
3. In the period of the fetus, accelerated growth of craniofacial structures occurs resulting in increased size and changes in proportions, and the prenatal growth of structures such as the cranial base, maxilla, mandible, palate, and mandible are described.
This document discusses embryogenesis and prenatal face formation. It covers early embryonic development from fertilization through the fetal period. Key points include:
- Embryogenesis occurs in three main periods: preimplantation, embryonic, and fetal.
- The pharyngeal arches play an important role in face development, with each arch contributing muscles, nerves, and blood vessels.
- Organ systems like the cardiovascular, digestive, and nervous systems undergo differentiation during the somite period from 3-4 weeks.
- The postsomite period from 5-8 weeks sees formation of external features and digit development. The embryo is now termed a fetus.
The document summarizes the embryology of the head and neck region. It discusses that the mesenchyme that forms the head is derived from mesoderm, neural crest cells, and thickened ectoderm. There are 5 pairs of branchial arches that form the basis of all head and neck structures. Each arch contains mesenchyme, ectoderm, endoderm, blood vessels, cartilage, muscles and nerves. The arches give rise to many structures in the head and face through the ossification and differentiation of these components.
The document discusses the development of the face and palate from embryology. It begins with an introduction to embryology and the formation of germ layers. It then covers the development of the five facial primordia around the stomodeum in the fourth week. This includes the frontonasal prominence and paired maxillary and mandibular prominences. It also discusses the formation of the nasal placodes, lips, eyes, and ears from the facial prominences. The document next explains palatogenesis, including the development of the primary and secondary palate from the sixth to twelfth weeks. It concludes with anomalies that can occur during craniofacial development.
The document summarizes the development of the face from the 4th week of embryonic development. It discusses how the frontonasal prominence, maxillary prominences, and mandibular prominences form the basic structures of the face. It describes the development of specific structures like the nose, palate, ears, eyes, lips, and tongue from these prominences. It also discusses the theories of craniofacial growth and the role of the pharyngeal arches, pouches, grooves, and clefts in facial development.
Influence of orofacial functions on development of face and occlusionmohammed alawdi
1) Orofacial functions like sucking and swallowing influence facial and dental development. Abnormal or prolonged functions can cause malocclusions.
2) Common orofacial habits in children include thumb sucking, tongue thrusting, and mouth breathing. These habits can result in open bites, protruded teeth, and narrow arches.
3) Treatment depends on the child's age and severity of the malocclusion. Younger children may need reminder therapy while older children may require appliances to correct positioning and arch constriction.
This document discusses the development of the face and oral cavity from early embryonic stages through postnatal growth. It covers topics like germ cell formation and fertilization, the formation of the three germ layers and neural tube, development of the branchial arches and pharyngeal pouches, shifts in blood supply to the face, development of muscles and cartilage, and prenatal and postnatal growth patterns. The development of the face and oral cavity involves complex interactions between ectoderm, mesoderm, endoderm, and neural crest cells during embryonic and fetal development.
The document discusses the development of the face from the 4th week of embryonic development. It describes how the face develops from three prominences - the frontonasal process and right and left maxillary and mandibular processes. It provides details on how various structures are formed from the fusion and development of these prominences, including the upper lip, lower lip, cheek, nose, palate and muscles of the face. The document also briefly discusses some common developmental anomalies of the face like cleft lip and cleft palate.
phayrangeal apparatus By Dr.Aisha Sadaf IBMS -KMU-peshawarAisha Sadaf
The document describes the development of the pharyngeal arches, pouches, and clefts in early human embryogenesis. It states that the pharyngeal arches develop as six curved mesenchymal thickenings on each side of the primitive pharynx. Each arch gives rise to specific skeletal, muscular, vascular and nervous derivatives. The pharyngeal pouches form as outpocketings between the arches and give rise to structures such as the tonsils and parathyroid glands. Pharyngeal clefts form between the pouches and contribute to structures like the external auditory meatus. Congenital anomalies can result if development of the arches, pouches or clefts is disrupted.
The face develops between the 4th and 6th week of embryonic development from structures including the frontonasal process, mandibular arches, and maxillary processes. Between the 6th and 12th week, the palate begins to form through the fusion of the palatal shelves, separating the nasal and oral cavities. Abnormalities can occur if the fusion of structures like the medial nasal processes, mandibular arches, or palatal shelves is incomplete, leading to cleft lip, cleft palate, or other anomalies. A thorough understanding of normal facial development aids in diagnosing and treating congenital defects.
Development of dentition /certified fixed orthodontic courses by Indian denta...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Growth & development of face/certified fixed orthodontic courses by India...Indian dental academy
The document discusses the development and growth of the face from early embryogenesis through adulthood. It describes how the face develops from five prominences surrounding the mouth, including the frontonasal, paired maxillary, and paired mandibular processes. It also discusses the development of structures like the nose, eyes, ears, palate and branchial arches and how anomalies can occur. The growth and anatomy of the face is then covered, addressing topics like muscles, nerves, arteries, growth patterns and theories.
Face develops in humans between 4th – 10th week of intrauterine life.
prenatal growth of the maxilla
DEVELOPMENT OF UPPER LIP
Development of lower lip
Development of nose
hare lip
OBLIQUE FACIAL CLEFT
macrostomia
lateral facial cleft
microstomia
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Development of Face /certified fixed orthodontic courses by Indian dental ac...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
01. pharyngeal arches (3 lectures, march 18)monazain3
The pharyngeal apparatus consists of pharyngeal arches, pouches, grooves, and membranes that contribute to development of the head and neck. By the 4th week of development, 4 pairs of pharyngeal arches are present externally and are separated by pharyngeal grooves. The arches give rise to important structures of the face, neck, and organs through their mesenchymal, cartilaginous, muscular, and nervous components. Derivatives of the pharyngeal arches include bones, muscles, blood vessels, and nerves that form the jaw, tongue, larynx, and other head and neck structures.
1. The cranial end of the embryo folds first due to the rapid growth of the brain, forming the primitive oral cavity and stomatodeum.
2. The face develops from five mesodermal elevations called processes that are augmented by neural crest cells and lined with ectoderm. These include the frontonasal process, two maxillary processes, and two mandibular processes.
3. The frontonasal process forms the forehead and nose. The maxillary processes form parts of the upper lip, cheek, and palate. The mandibular processes merge to form the lower lip and chin.
The head and neck develop from the first four pharyngeal arches and are highly complex structures requiring contributions from all three germ layers. The pharyngeal arches give rise to many structures in the head including bones, muscles and nerves. The face develops from fusion of the frontonasal process and medial and lateral nasal processes between 4-7 weeks. The primary palate arises from the medial nasal process while the secondary palate develops from fusion of the two palatine processes between 7-12 weeks. The tongue develops from the first four pharyngeal arches and the maxilla develops from the dorsal end of the first pharyngeal arch.
This document provides an overview of facial development from fertilization through the formation of facial structures. It discusses the formation and fate of the germ layers and pharyngeal arches, which give rise to facial tissues and structures. Key stages of development discussed include formation of the lens, nose, cheeks, eyes, external ear, and palate. Common anomalies in facial development are also summarized, such as cleft lip and palate.
The document summarizes prenatal and postnatal growth and development of the face. It describes how the face increases in size much more during the prenatal period compared to postnatal growth. It outlines the development of the face from the gestational periods and formation of the primordia. It discusses common anomalies during development and functional therapies. The craniofacial bones undergo remodeling and fusion during childhood with the skull assuming the adult shape by adolescence.
1. The document discusses prenatal facial growth, which can be divided into three periods: the period of the ovum, embryo, and fetus.
2. During the period of the embryo (1-7 weeks), the major development of the facial and cranial regions occurs, including the formation of the branchial arches which give rise to structures of the face, neck, and throat.
3. In the period of the fetus, accelerated growth of craniofacial structures occurs resulting in increased size and changes in proportions, and the prenatal growth of structures such as the cranial base, maxilla, mandible, palate, and mandible are described.
This document discusses embryogenesis and prenatal face formation. It covers early embryonic development from fertilization through the fetal period. Key points include:
- Embryogenesis occurs in three main periods: preimplantation, embryonic, and fetal.
- The pharyngeal arches play an important role in face development, with each arch contributing muscles, nerves, and blood vessels.
- Organ systems like the cardiovascular, digestive, and nervous systems undergo differentiation during the somite period from 3-4 weeks.
- The postsomite period from 5-8 weeks sees formation of external features and digit development. The embryo is now termed a fetus.
The document summarizes the embryology of the head and neck region. It discusses that the mesenchyme that forms the head is derived from mesoderm, neural crest cells, and thickened ectoderm. There are 5 pairs of branchial arches that form the basis of all head and neck structures. Each arch contains mesenchyme, ectoderm, endoderm, blood vessels, cartilage, muscles and nerves. The arches give rise to many structures in the head and face through the ossification and differentiation of these components.
The document discusses the development of the face and palate from embryology. It begins with an introduction to embryology and the formation of germ layers. It then covers the development of the five facial primordia around the stomodeum in the fourth week. This includes the frontonasal prominence and paired maxillary and mandibular prominences. It also discusses the formation of the nasal placodes, lips, eyes, and ears from the facial prominences. The document next explains palatogenesis, including the development of the primary and secondary palate from the sixth to twelfth weeks. It concludes with anomalies that can occur during craniofacial development.
The document summarizes the development of the face from the 4th week of embryonic development. It discusses how the frontonasal prominence, maxillary prominences, and mandibular prominences form the basic structures of the face. It describes the development of specific structures like the nose, palate, ears, eyes, lips, and tongue from these prominences. It also discusses the theories of craniofacial growth and the role of the pharyngeal arches, pouches, grooves, and clefts in facial development.
Influence of orofacial functions on development of face and occlusionmohammed alawdi
1) Orofacial functions like sucking and swallowing influence facial and dental development. Abnormal or prolonged functions can cause malocclusions.
2) Common orofacial habits in children include thumb sucking, tongue thrusting, and mouth breathing. These habits can result in open bites, protruded teeth, and narrow arches.
3) Treatment depends on the child's age and severity of the malocclusion. Younger children may need reminder therapy while older children may require appliances to correct positioning and arch constriction.
This document discusses the development of the face and oral cavity from early embryonic stages through postnatal growth. It covers topics like germ cell formation and fertilization, the formation of the three germ layers and neural tube, development of the branchial arches and pharyngeal pouches, shifts in blood supply to the face, development of muscles and cartilage, and prenatal and postnatal growth patterns. The development of the face and oral cavity involves complex interactions between ectoderm, mesoderm, endoderm, and neural crest cells during embryonic and fetal development.
The document discusses the development of the face from the 4th week of embryonic development. It describes how the face develops from three prominences - the frontonasal process and right and left maxillary and mandibular processes. It provides details on how various structures are formed from the fusion and development of these prominences, including the upper lip, lower lip, cheek, nose, palate and muscles of the face. The document also briefly discusses some common developmental anomalies of the face like cleft lip and cleft palate.
phayrangeal apparatus By Dr.Aisha Sadaf IBMS -KMU-peshawarAisha Sadaf
The document describes the development of the pharyngeal arches, pouches, and clefts in early human embryogenesis. It states that the pharyngeal arches develop as six curved mesenchymal thickenings on each side of the primitive pharynx. Each arch gives rise to specific skeletal, muscular, vascular and nervous derivatives. The pharyngeal pouches form as outpocketings between the arches and give rise to structures such as the tonsils and parathyroid glands. Pharyngeal clefts form between the pouches and contribute to structures like the external auditory meatus. Congenital anomalies can result if development of the arches, pouches or clefts is disrupted.
The face develops between the 4th and 6th week of embryonic development from structures including the frontonasal process, mandibular arches, and maxillary processes. Between the 6th and 12th week, the palate begins to form through the fusion of the palatal shelves, separating the nasal and oral cavities. Abnormalities can occur if the fusion of structures like the medial nasal processes, mandibular arches, or palatal shelves is incomplete, leading to cleft lip, cleft palate, or other anomalies. A thorough understanding of normal facial development aids in diagnosing and treating congenital defects.
Development of dentition /certified fixed orthodontic courses by Indian denta...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The document summarizes the development of the face from the 4th week of embryonic development. It discusses how the frontonasal process, maxillary processes, and mandibular processes form the structures of the face, including the lips, nose, eyes, ears, and palate. It also describes the development of branchial arches and how they contribute to specific muscles, nerves, arteries, and bones. The formation and differentiation of the pharyngeal pouches and clefts that form parts of the ear, thyroid, parathyroid glands and thymus are also outlined.
Craniofacial growth is a complex and a beautiful phenomenon.
It all begins when a sperm cell fuses with an egg cell, a process called fertilization.
Human fertilization is the union of a human egg and sperm, usually occurring in the ampulla of the fallopian tube. The result of this union is the production of a ’Zygote’ cell, or fertilized egg, initiating prenatal development
Prenatal growth can be divided into 3 main stages:
Germinal stage: From ovulation to implantation(0-2 weeks).
Embryonic stage : 3rd week to 8th week.
Fetal stage: 9th week till birth.
The document summarizes facial development from the 4th to 8th weeks of gestation. It describes how the frontonasal prominence forms the forehead and nose while the maxillary prominences form the upper lip and cheek and the mandibular prominences form the lower lip, chin and cheek. It also discusses nasal cavity development including formation of the nasal sac and choanae as well as development of the palate, paranasal sinuses, and bones of the skull.
Growth & development of maxilla & mandible.ppt [autosaved]Priyanka Doshi
This document discusses the growth and development of the maxilla and mandible. It begins by defining growth and development. It then describes the mechanisms of bone growth and the two types of ossification - intramembranous and endochondral. Prenatal growth is divided into the periods of the ovum, embryo and fetus. Details are provided on the prenatal growth of the maxilla, including the development of the palate. Prenatal growth of the mandible and development of Meckel's cartilage are also outlined. The document concludes with descriptions of postnatal growth of the maxilla and mandible through processes like displacement, growth at sutures and surface remodeling.
The document discusses the development of the face from the embryonic to fetal periods. It covers the formation of the pharyngeal arches and how they give rise to structures like the mandible, maxilla and palate. It also describes the development of other facial features such as the nose, sinuses, lips, tongue, teeth and salivary glands from the pharyngeal arches and surface ectoderm. Common anomalies arising from defects in these developmental processes are also mentioned.
This document summarizes the development of the maxilla and mandible prenatally and postnatally. Prenatally, the maxilla develops from the maxillary prominence and ossifies around 4 weeks gestation near the infraorbital nerve. The premaxilla also ossifies early and fuses with the maxilla. Palatine bones develop near the nasal capsule. Postnatally, the maxilla and palate grow through surface deposition, remodeling, and sutural growth. The mandible initially develops from Meckel's cartilage in the first pharyngeal arch and undergoes endochondral ossification through a condylar cartilage, allowing continued growth.
The ear develops from three germ layers into three main structures - the inner, middle, and outer ear. The outer ear develops from hillocks in the mandibular and hyoid arches, which fuse to form the pinna. The external auditory canal develops from the first branchial groove. The middle ear cavities develop from outpouchings of the first and second pharyngeal pouches. Ossicles develop from the first and second branchial arches. The inner ear develops from the otic placode, forming the fluid-filled cochlea and vestibular system. The facial and acoustic nerves also develop during this period to innervate the ear structures.
1. The document discusses the development of the face and oral cavity from early prenatal growth through maturation. It describes how the five facial prominences, including the frontonasal, maxillary, and mandibular processes, develop and give rise to different structures.
2. Key stages of development discussed include formation of the oral cavity from the stomodeum, separation of the nasal cavity by fusion of the medial nasal processes, and separation of the oral and nasal cavities by formation and fusion of the secondary palate from palatine shelves.
3. Glands such as the parotid, submandibular, and sublingual glands develop from epithelial buds in the oral cavity and surrounding
Development of Face and Palate including Anomalies of palate Ragya Bharadwaj
The face develops between 4-6 weeks of embryonic development. Key structures include the pharyngeal arches and neural crest cells. The pharyngeal arches give rise to structures like the jaw and palate, while neural crest cells contribute to structures like the nose. The nasal pits form from placodes and fuse with other prominences. The primary palate forms from fusion of the medial nasal prominences, while the secondary palate develops from the palatal shelves fusing. Cleft lip and palate can occur if these fusion processes fail.
The document outlines craniofacial development from embryology through birth. It discusses how facial tissues originate from ectoderm and neural crest cells. It describes 5 stages of craniofacial development from germ layer formation to organ system formation. Common craniofacial disorders are explained such as fetal alcohol syndrome, cleft lip/palate, and craniosynostosis syndromes. Growth and development of specific structures like the nose, palate, and mandible are detailed. Growth mechanisms and sites are compared for cranial vault, cranial base, nasomaxillary complex, and mandible.
The document discusses prenatal growth of the maxilla and mandible. It begins by providing definitions of growth, development, and the correlation between the two. It then describes the prenatal embryology and ossification of the maxilla, including the development of the palate and maxillary sinus. For the mandible, it discusses the pharyngeal arches, Meckel's cartilage, ossification centers, and endochondral bone formation including the condylar and coronoid processes.
This document provides an overview of craniofacial embryology, covering early orofacial development including the pharyngeal arches and pouches, calvaria, cranial base, facial skeleton, palate, paranasal sinuses, mandible, temporomandibular joint, tongue, tonsils, and salivary glands. It discusses the development of each structure in detail from the early gestational weeks through birth and childhood, including ossification centers, fusion of bones, and pneumatization of sinuses. It also notes some anomalies that can occur in development.
PRENATAL AND POST NATAL GROWTH AND DEVELOPMENT OF NASOMAXILLARY COMPLEXB NITIN KUMAR
This document provides an overview of prenatal and postnatal growth and development of the nasomaxillary complex. It discusses the prenatal periods of ovum, embryo, and fetus, and how structures like the palate, orbits, and nasal cavity develop during these periods. Postnatally, it describes growth mechanisms like drift and displacement that affect structures in the nasomaxillary complex like the maxilla, palate, zygomatic bone, and nasal cavity. Primary displacement of the maxillary tuberosity is a major driver of maxillary growth postnatally.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
PRENATAL GROWTH OF MANDIBLE
Occurs between the 4th and 7th week of intrauterine life.
4th week of intrauterine life
Formation of the head fold
Following which the developing brain and the pericardium form 2 prominent bulges on the ventral aspect of the embryo.
The 2 bulges are separated from each other by a shallow depression called stomatoedum (corresponding to the primitive mouth).
Floor of the stomatodeum is formed by the Buccopharyngeal membrane, which separates the stomatodeum from the foregut.Soon, mesoderm covering the developing forebrain proliferates, and forms a downward projection that overlaps the upper part of the stomatodeum – this downward projection is called frontonasal process.
Cleft lip and palate can occur individually or together. They have varying incidence rates among races. Treatment involves a multidisciplinary team and occurs in stages:
Stage I from birth to 18 months includes maxillary obturators, presurgical orthopedics, lip and palate surgery.
Stage II from 18 months to 5 years addresses the primary dentition with obturator adjustments and restorations.
Stage III from 6 to 11 years involves correcting crossbites during mixed dentition.
Stage IV from 12 to 18 years uses orthodontics and prosthodontics to complete treatment during permanent dentition. The goal is successful rehabilitation through a coordinated, long-term approach.
- Biomechanics in orthodontics refers to the reaction of dental and facial structures to orthodontic forces.
- Key concepts in biomechanics include force, center of mass, center of resistance, center of rotation, moment, and couple.
- The different types of tooth movement that can occur due to forces and moments include tipping, translation, root movement, rotation, intrusion, and extrusion. Efficient orthodontic treatment requires sound treatment plans backed by sound mechanical/biomechanical plans.
This document discusses the Twin Block functional appliance, including its development, designs, mode of action, and treatment techniques. It introduces the Twin Block, developed in 1977 to treat a young patient. Key features and benefits are outlined, along with bite registration procedures, component designs, and treatment stages. Modifications for treating various malocclusions are described, along with integration with fixed appliances. The versatility of the Twin Block for treating different malocclusions is emphasized.
Trigeminal neuralgia (TN), also known as tic douloureux, causes severe facial pain and is described as among the most excruciating pains. It is characterized by sporadic shock-like pains in areas of the face innervated by the trigeminal nerve. Common triggers include eating, talking, and facial touch. The condition is caused by blood vessel compression of the trigeminal nerve root at its entry point to the brainstem. Diagnosis is based on symptoms and neurological exam. Treatment options include medications, microvascular decompression surgery, and percutaneous rhizotomy procedures to ablate nerve fibers.
Surgical orthodontics procedures are carried out as an adjunct to orthodontic treatment to eliminate etiologic factors or correct severe dentofacial abnormalities. Major procedures include extractions of teeth, surgical uncovering of impacted teeth, frenectomy, pericision, and corticotomy. Minor procedures include extractions of carious, malformed, supernumerary, and impacted teeth. Orthodontic surgeries are used to treat severe orofacial disproportions not amenable to orthodontics alone and involve various osteotomies and genioplasty procedures. Pre-treatment diagnosis and planning includes medical evaluation, radiographs, study models, and cephalometric analysis.
Stainless steel is an alloy of iron and chromium that is resistant to corrosion. There are three main types of stainless steel - ferritic, martensitic, and austenitic. Austenitic stainless steel contains 18% chromium, 8% nickel, and 0.08-0.15% carbon and is the type most commonly used in dentistry. Removable appliances can be used to guide eruption, upright teeth, and allow for spontaneous tooth movement. They are fabricated using components like clasps, springs, and screws to apply forces. Common types of clasps include C-clasps, Jackson clasps, and Adam's clasps, which are made of wire and engage undercuts for retention.
This document discusses space maintainers, which are appliances used to maintain space lost prematurely due to tooth extraction. It defines space maintainers and classifies them as fixed or removable, functional or non-functional, unilateral or bilateral, active or passive, with or without bands, and combinations. Requirements for space maintainers are outlined, and removable, fixed, and specific types of space maintainers like distal shoe and crown and loop are described, including their advantages, disadvantages, and indications for use. Planning factors for space maintainers like time since tooth loss and dental age are also covered.
This document discusses skeletal maturity indicators that can be used to assess a patient's biological age and remaining growth potential. It describes how chronological age alone is not enough, and that skeletal age determined from hand wrist radiographs provides a more accurate assessment. The document outlines several methods for assessing skeletal age, including the Fishman skeletal maturity indicators and the Modified MP3 Cervical Vertebrae Maturation Index. It explains what each method evaluates and the stages involved. Assessing skeletal age is important for orthodontic treatment planning to determine treatment timing and prognosis.
Retention and relapse are important concepts in orthodontics. Retention is maintaining the corrected tooth positions after treatment, while relapse is the loss of correction. There are several theories on retention, including proper occlusion, apical base positioning, and mandibular incisor positioning. Retainers help maintain corrections and come in removable and fixed varieties. Factors that can lead to relapse include stretched periodontal ligament fibers, growth changes, inadequate bone adaptation, muscle imbalances, untreated etiologies, and third molar eruption. Maintaining corrections long-term may require permanent retention.
Preventive orthodontics aims to educate patients and parents, monitor growth and development, diagnose potential malocclusions, and treat issues before they arise. Preventive procedures include parent education, caries control, managing deciduous teeth, extracting supernumerary teeth, and treating habits. Space maintainers are used to preserve space from lost deciduous teeth. Removable space maintainers are easy to clean but can be lost, while fixed types do not interfere with eruption but require more skill. Common space maintainers include band and loop, lingual arch, distal shoe, and acrylic partial dentures.
The cranial base grows postnatally through processes like cortical drift and remodeling, elongation at synchondroses, and sutural growth. The maxilla and mandible are attached to the growing cranial base and are displaced downward and forward as the cranial base grows. The maxilla also grows through sutural growth and surface remodeling while the mandible grows through remodeling of processes like the ramus, body, angle, lingual tuberosity, alveolar process, chin, condyle, and coronoid process. Growth of the cranial base, maxilla, and mandible continues until late adolescence to accommodate the developing dentition.
Orthognathic surgery involves surgical procedures to correct dentofacial deformities involving the maxilla, mandible, or both. It is carried out along with orthodontic treatment. Indications include severe class II or III malocclusions, deep overbites, open bites, vertical excess or deficiency, asymmetry, and compromised periodontal health. The goals are optimal facial and dental aesthetics, functional occlusion, future oral health, rapid treatment, stability, and minimal morbidity. Treatment requires joint planning by an orthodontist and oral surgeon, including presurgical orthodontics, surgical splint fabrication, and sagittal, transverse, or vertical surgical procedures like le fort osteotomies or sagittal split
Orthodontic study models are accurate reproductions of a patient's teeth and surrounding tissues that are important diagnostic aids for orthodontists. Ideal study models accurately reproduce the dental anatomy without distortion, are trimmed symmetrically for easy identification of asymmetries, accurately reproduce occlusion when placed on their backs, and have a clean smooth surface while depicting as much of the alveolar process as possible. Study models consist of an anatomical stone plaster portion imprinted from the dental impression and an artistic plaster base that supports the anatomical portion and gives the models a pleasing symmetrical appearance.
This document discusses soldering and welding techniques for joining metals. It describes soldering as joining metals with a lower-melting alloy called solder. Key requirements for good solder include having a melting point below the base metals and similar strength. Hard solders like gold and silver solders are used in dentistry. Welding joins metals without another alloy, using techniques like spot welding, arc welding, and laser welding. Spot welding passes a current through the metals to generate heat and join them, while maintaining pressure until cooled. Fluxes are also discussed which help remove oxides during the process. Proper cleaning, temperature control, pressure, and techniques are needed for successful soldering and welding.
This document provides an overview of orthodontic diagnosis procedures. It discusses the importance of collecting pertinent data in a systematic manner to identify the nature and cause of orthodontic problems. The summary includes:
1. Essential diagnostic aids include case history, clinical examination, study models, and certain radiographs to assess the malocclusion.
2. The document outlines procedures for examining a patient's medical history, dental history, facial symmetry, jaw relationships, dentition, and functional assessment.
3. Functional examination assesses factors like postural rest position, path of closure, respiration, swallowing, and temporomandibular joint function to evaluate normal function.
This document provides an overview of orthodontic appliances, including definitions, classifications, components, and examples. It discusses both removable and fixed appliances. Removable appliances are further divided into active, passive, and orthopedic categories. Examples of removable appliances include Hawley's retainers, Begg's retainers, bite plates, habit breakers, and space maintainers. Fixed appliances include brackets, wires, elastics, and functional appliances like Herbst and Twin Block. The document also covers indications, contraindications, advantages, and disadvantages of removable appliances as well as fabrication methods.
- The document discusses several dental cast analysis methods, including Ashley Howe's analysis, Pont's analysis, Bolton's analysis, and Moyer's mixed dentition analysis.
- These analyses involve measuring tooth widths, arch widths, and comparing values to determine discrepancies and space availability. Factors like crowding, extraction needs, and arch expansion potential are assessed.
- Specific measurements and formulas are provided to calculate values like total tooth material, premolar diameters, arch widths, tooth size ratios, and predicted widths of unerupted teeth based on erupted teeth.
This document discusses various methods of gaining space in orthodontic treatment, including:
1. Proximal stripping, expansion of arches, distalization, protracting anteriors, derotation of posteriors, and uprighting of molars.
2. Specific techniques are described like slow expansion using coffin springs or quad helix appliances, and rapid maxillary expansion using hyrax expanders.
3. Distalization methods include extra-oral forces, pendulum appliances, and lip bumpers.
4. Extractions, particularly of premolars, are also discussed as a space gaining technique, though recent advances aim to reduce reliance on extractions.
Orthodontics involves correcting teeth alignment and positioning. It aims to achieve functional efficiency, structural balance, and esthetic harmony through treatments like preventive, interceptive, corrective, and surgical orthodontics. Edward Hartley Angle is considered the father of modern orthodontics. He developed classifications of malocclusions and appliances like pin and tube and edgewise appliances. Other contributors included Calvin Case, Martin Dewey, Holly Broadbent, Raymond Begg, and Rolf Frankel who developed growth guidance appliances.
This document discusses interceptive orthodontics, which aims to prevent potential malocclusions from progressing into more severe ones. Key procedures discussed include serial extraction, correction of developing crossbites, controlling abnormal habits, regaining space after premature tooth loss, closing diastemas, muscle exercises, intercepting skeletal malrelations, and removing soft tissue or bony barriers inhibiting tooth eruption. Serial extraction involves the planned extraction of certain teeth to guide others into favorable positions. Developing anterior crossbites should be corrected early to prevent skeletal malocclusions. Interceptive orthodontics recognizes and eliminates irregularities and malpositions early to guide proper development.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
2. During this period, the height increases by almost 5000 times as
compared to only a threefold increase during the post natal period. It is
divided into 3 periods –
Period of the Ovum – This period extends for two weeks from the
time of fertilization. During this period the cleavage of the ovum and
attachment of the ovum to the intra uterine wall occurs.
Period of the Embryo – This period extends from the 14th day to the
56th day of intra uterine life. Major part of the development of the facial
and cranial region occurs during this time.
Period of the Foetus – This phase extends between the 56th day of
intrauterine life till birth. In this period, accelerated growth of the cranio-
facial structures occurs resulting in an increase in their size. There is also
a change in proportion between the various structures.
3. Pre Natal Growth Of Cranial Base
The earliest evidence of formation of the cranial base is seen in the
post/late somitic period [4th – 6th week of intra uterine life]. During this
period mesenchymal tissue derived from primitive streak, neural crest
and occipital sclerotomes condense around the developing brain and
form a capsule which is known as Ectomenix or Ectomeningeal capsule. A
portion of this capsule gives rise to the future cranial base.
Evidence of skull formation is seen late after development of other cranial
structures.
From around 40th day onwards, the Ectomeningeal capsule is slowly
converted into cartilage. This is the onset of cranial base formation. The
conversion of mesenchymal cells into cartilage or chondrification occurs
in 4 regions –
• Parachordal
• Hypophyseal
• Nasal
• Otic
4. • Parachordal – The chondrification centers which form around the
cranial end of the notochord are called Parachordal cartilages.
• Hypophyseal – Cranial to the termination of notochord, the
Hypophyseal pouch develops which gives rise to the anterior lobe of the
pituitary gland.
[i] On both sides of hypophyseal stem two post sphenoid cartilages
develop, which fuse together and form the posterior part of the body of
sphenoid.
[ii] Cranial to pituitary gland, two trabecular cartilages develop which
fuse together and form the anterior part of body of sphenoid.
[iii] Lateral to pituitary gland, chondrification centers are seen which
form the lesser wing and greater wing of sphenoid.
5. • Nasal – Initially a capsule is seen around the nasal sense organ. This
capsule chondrifies and forms the cartilages of the nostrils, which later
fuses with the cartilages of the cranial base.
• Otic – Initially a capsule is seen around the vestibulo-cochlear sense
organs which condrifies and later ossifies to give rise to the mastoid and
petrous portions of the temporal bone. The otic cartilages also fuse with
the cartilages of the cranial base.
The initially separate centres of cartilage formation in the cranial base
fuse together into a single irregular and perforated cranial base.
Numerous nerves, blood vessels result in perforations or foramina in the
developing cranial base. The ossifying chondro-cranium meets the
ossifying cranial vault to form the neurocranium.
6.
7. Chondro – Cranial Ossification
The cranial base which is in a cartilagenous form undergoes ossification.
The bones of the cranial base undergo both endochondral and
intramembranous ossification.
• Occipital Bone – It shows both types of ossification. Seven ossification
centres are seen, 2 intra membranous and 5 endochondrial.
• Temporal Bone – It also ossifies both endochondrally and intra-
membranously from 11 centres.
• Ethmoid Bone – It shows only endochondrial ossification. It ossifies
from 3 centres.
• Sphenoid Bone – It ossifies by both types from 15 ossification centres.
The cranial base or chondrocranium is important as a junction between the
cranial vault and the facial skeleton, being shared by both. The cranial
base is relatively stable during growth as compared to the cranial vault
and the face. Therefore the cranial base can be taken as a basis against
which the cranial vault and facial skeleton can be compared.
8. Flexure Of The Cranial Base -
During the embryonic and early fetal period, the cranial base becomes
flexed in the region between the pituitary fossa and the spheno-occipital
junction. The face is tucked under the cranium. This flexure of the cranial
base is accompanied by a corresponding flexure of the developing brain
stem.
The spinal chord and foramen magnum, which during the early stages of
development were directed backwards, now become directed
downwards.
9. Uneven growth of Cranial Base
The uneven growth of the cranial base is due to the uneven nature of
growth seen in different regions of brain.
The flexure of cranial base aids in increasing the neurocranial capacity
and is the main reason for the downward displacement of face during
growth.
At 10th week of intra uterine life, the flexion of the base is about 65
degrees. This flattens out a bit at the time of birth.
10. Pre-Natal Embryology Of Maxilla
Around the 4th week of intra uterine life, a prominent bulge appears on
the ventral aspect of the embryo corresponding to the developing brain.
Below the bulge, a shallow depression which corresponds to the primitive
mouth appears called stomadeum. The floor of the stomadeum is formed
by the buccopharyngeal membrane which separates the stomadeum from
the foregut.
By around 4th week of intrauterine life, 5 brachial arches form in the
region of the future head and neck. Each of these arches gives rise to
muscles, connective tissue, vasculature, skeletal components and neural
components of the future face. The 1st brachial arch is the mandibular
arch and plays an important role in the development of the naso-
maxillary region.
The mesoderm covering the developing forebrain proliferates and forms a
downward projection that overlaps the upper part of the stomadeum.
This downward projection is called Fronto-nasal process.
11. The stomadeum is thus overlapped superiorly by the frontonasal process,
while the mandibular arches of both the sides form the lateral walls of
the stomadeum. The mandibular arch gives a bud from it’s dorsal end
called the Maxillary Process. The maxillary process grows ventro-
medio-cranial to the main part of the mandibular arch, which is now
called Mandibular Process. Thus, at this stage the primitive mouth or
stomadeum is overlapped from above by the frontal process, below by
the mandibular process and on either sides by the maxillary processes.
The ectoderm overlying the fronto-nasal process shows bilateral localized
thickening above the stomadeum. These are called as the Nasal
Placodes. These placodes soon sink and form the nasal pits.
The formation of these nasal pits divides the fronto nasal process into 2
parts – medial and lateral nasal processes.
The two mandibular processes grow medially and fuse to form the lower
lip and lower jaw. As the maxillary process undergoes growth, the fronto
nasal process becomes narrow so that the two nasal pits come closer.
12.
13. Development Of Palate
The palate is formed by contributions of the maxillary process, palatal
shelves given off by maxillary process and Fronto – nasal process.
The fronto-nasal process gives rise to the premaxillary region while the
palatal shelves form the rest of the palate. As the palatal shelves grow
medially, their union is prevented by the presence of the tongue. Thus,
initially the developing palatal shelves grow vertically downwards towards
the floor of the mouth.
14. Around 7th week of intra-uterine life, a quick transformation in the
position of the palatal shelves occurs and they change from a vertical to
a horizontal position.
By 8.5 weeks of intra-uterine life, the two palatal shelves are in close
approximation with each other. Initially they are covered by an epithelial
lining but as they join the epithelial cells degenerate. The connective
tissue from the palatal shelves intermingle with each other and fuse.
The entire palate doesn’t contact and fuse at the same time. Initially
contact occurs in the central region of the secondary palate , then
closure occurs anteriorly and posteriorly.
The mesial edges of the palatal processes fuse with the free lower end of
nasal septum and thus separates the two nasal cavities from each other
and the oral cavity.
15. Ossification of Palate – Occurs from 8th week of intra-uterine life. Its is
intra-membranous type of ossification. The palate ossifies from a single
center derived from the maxilla. The most posterior part of the palate
does not ossify and forms the soft palate. The mid-palatal suture ossifies
by 12-14 years.
Development of Maxillary Sinus – It forms around 3rd month of intra-
uterine life. It develops by expansion of the nasal mucous membrane into
the maxillary bone. Later the sinus enlarges by resorption of the internal
wall of maxilla.
16. Pre-Natal Embryology Of Mandible
Around 4th week of intra-uterine life, the developing brain and
pericardium form two prominent bulges on the ventral aspect of the
embryo. These bulges are separated by the primitive oral cavity or
stomadeum. The floor of the stomadeum is by bucco-pharyngeal
membrane which separates it from the foregut.
The pharyngeal arches are laid down on the lateral and ventral aspects of
the cranialmost part of the foregut which lies in close approximation with
the stomadeum. Initially there are six pharyngeal arches, but the 5th one
disappears as soon as it is formed leaving only five. They are separated
by four branchial grooves. The first arch is called as the mandibular arch
and the second arch, hyoid arch. The other arches do not have any
specific names.
Each of these five arches contain a central cartilage rod that forms the
skeleton of the arch, a muscular component, a vascular component and a
neural component.
17. The mandibular arch forms the lateral wall of the stomadeum. It gives a
bud at its dorsal end which is called as maxillary process. It grows
ventro-medially, cranial to the main part of the arch, which is now called
as the mandibular process. The mandibular processes grow towards each
other and fuse in midline. They now form the lower border of the
stomadeum i.e. the lower lip and the lower jaw.
Meckel’s Cartilage
It is derived from the 1st branchial arch around the 41st – 45th day of
intra-uterine life. It extends from the cartilagenous otic capsule to the
midline or symphysis and provides a template for guiding the growth of
the mandible. A major part of Meckel’s cartilage disappears during
growth and the remaining part develops into – mental ossicles, incus and
malleus, spine of sphenoid bone, anterior ligament of malleus and
spheno-mandibular ligament.
The first structure to develop in the primordium of the lower jaw is the
mandibular division of the trigeminal nerve. This is followed by
mesenchymal condensation forming the first branchial arch. Neurotrophic
factors produced by the nerve induce osteogenesis in the ossification
centers.
18. A single ossification center for each half of mandible arises in 6th week of
intra-uterine life in the region of the bifurcation of the inferior alveolar
nerve into mental and incisive branches.
The ossifying membrane is located lateral to the Meckel’s cartilage. From
this primary center, ossification spreads below and around the inferior
alveolar nerve and its incisive and branch and upwards to form a trough
for accommodating the developing tooth buds. Spread of the
intramembranous ossification dorsally and ventrally forms the body and
ramus of the mandible.
As ossification continues, the Meckel’s cartilage becomes surrounded and
invaded by bone. Ossification stops at the site that later becomes
mandibular lingula from where the Meckel;s cartilage continues into the
middle ear and develops into the auditory ossicles [malleus and incus].
19.
20. Endochondral Bone Formation
It is seen only in 3 areas of mandible – condylar process, coronoid
process and mental region.
• Condylar Process – At about 5th week of intra-uterine life, an area of
mesenchymal condensation can be seen above the ventral part of the
developing mandible. This develops into a cone shaped cartilage by
about 10th week and starts ossification by 14th week. It then migrates
inferiorly and fuses with the mandibular ramus by about 4 months. Much
of the cone shaped cartilage is replaced by bone by the middlw of fetal
life, but its upper end persists into adulthood acting both as a growth
cartilage and an articular cartilage.
• Coronoid Process – Secondary accessory cartilages appear in the
region of the coronoid process by about the 10-14th week of intra-uterine
life. This cartilage is believed to grow as a response to the developing
temporalis muscle. The coronoid accessory cartilage becomes
incorporated into the expanding intra-membranous bone of the ramus
and disappears before birth.
21. • Mental Region – In the mental region, on either side of the symphysis,
one or two small cartilages appear and ossify in the 7th month of intra-
uterine life to form variable numbers of mental ossicles in the fibrous
tissues of the symphysis. These ossicles become incorporated into the
intra-membranous bone when the symphysis ossifies completely during
the first year of post-natal life.