Chapter4 Growth and development of craniofacialand dentition in children Department ofPediatric Dentistry Zhang Hongmei vocabulary craniofacial颅面的dentition牙列growth生长development发育 fetus period胎儿期neonatal period新生儿期infancy period婴儿期 toddler period幼儿期preschool age学龄前期schoolage学龄期 adolescent period青春发育期lymphoid淋巴neural神经genital生殖 metabolic新陈代谢的endocrine内分泌的chromosomal染色体的 skeleton骨骼primordial原始的embryos胚胎osteogenic成骨的 intramembranous膜内的endochondral软骨内的ossification成骨 cranium颅parietal颅顶骨的occipital枕骨的sphenoid蝶骨 ethmoid筛骨的temporal bone颞骨hyperplasia增生maxillary上颌骨的 nasal鼻的stroma基质mandible下颌骨condylar髁的cartilage软骨 condyle髁突gems胚芽occlusion咬合lamina薄板intraosseous骨内的 epithelium上皮enamel牙釉质dental papilla牙乳头permanent teeth恒牙 anterior teeth前牙posteriorteeth后牙gestational age胎龄 primitive oral cavity原始口腔deciduous tooth乳牙incisor切牙 canine尖牙premolar tooth前磨牙nolar磨牙symmetrical对称的 mandibular下颌的upper jaws上颌lower jaws下颌primary teeth乳牙 pathological病理的lingual舌的mechanism机制Molecular分子的 lacuna腔隙masticatory咀嚼的malocclusion咬合不正periodontal牙周的 lateral movement横向运动dental arch牙弓proximal近端的distal末端的 primatespace灵长间隙developmental space发育间隙 physiological space生理间隙leeway space剩余间隙 intermaxillary space颌间间隙terminalplane末端平面overbite覆合 overjet覆盖embryonic胚胎的ugly ducking stage胚胎的丑小鸭阶段 labial唇的
Chapter 4 Growth and development of craniofacial and dentition in children Department of Pediatric Dentistry Zhang Hongmei vocabulary : craniofacial 颅面的 dentition 牙列 growth 生长 development 发育 fetus period 胎儿期 neonatal period 新生儿期 infancy period 婴儿期 toddler period 幼儿期 preschool age 学龄前期 school age 学龄期 adolescent period 青春发育期 lymphoid 淋巴 neural 神经 genital 生殖 metabolic 新陈代谢的 endocrine 内分泌的 chromosomal 染色体的 skeleton 骨骼 primordial 原始的 embryos 胚胎 osteogenic 成骨的 intramembranous 膜内的 endochondral 软骨内的 ossification 成骨 cranium 颅 parietal 颅顶骨的 occipital 枕骨的 sphenoid 蝶骨 ethmoid 筛骨的 temporal bone 颞骨 hyperplasia 增生 maxillary 上颌骨的 nasal 鼻的 stroma 基质 mandible 下颌骨 condylar 髁的 cartilage 软骨 condyle 髁突 germs 胚芽 occlusion 咬合 lamina 薄板 intraosseous 骨内的 epithelium 上皮 enamel 牙釉质 dental papilla 牙乳头 permanent teeth 恒牙 anterior teeth 前牙 posterior teeth 后牙 gestational age 胎龄 primitive oral cavity 原始口腔 deciduous tooth 乳牙 incisor 切牙 canine 尖牙 premolar tooth 前磨牙 molar 磨牙 symmetrical 对称的 mandibular 下颌的 upper jaws 上颌 lower jaws 下颌 primary teeth 乳牙 pathological 病理的 lingual 舌的 mechanism 机制 Molecular 分子的 lacuna 腔隙 masticatory 咀嚼的 malocclusion 咬合不正 periodontal 牙周的 lateral movement 横向运动 dental arch 牙弓 proximal 近端的 distal 末端的 primate space 灵长间隙 developmental space 发育间隙 physiological space 生理间隙 leeway space 剩余间隙 intermaxillary space 颌间间隙 terminal plane 末端平面 overbite 覆合 overjet 覆盖 embryonic 胚胎的 ugly ducking stage 胚胎的丑小鸭阶段 labial 唇的
Teaching content: Growthand developmentstages and characteristics ofeach stage The factors influencing growth and development The growth and development ofthe craniofacial skeleton The development oftoothand occlusion Master: The characteristics ofeach growth period thetiming and sequence of dental development growth and development stages oftooth and occlusion Familiar: Influencing factors of growth and development characteristics ofgrowth and development of upper and lower jaw and teeth Understand:Anatomical and physiological changes in dentition and occlusion development Section 1 Stages and Characteristics -、Stages (一)fetus period (二)neonatal period (三)infancy period (四)toddler period (五)preschool period (六)school period (adolescentperiod The relationship between the development and age Lymphoid type Neural type Generaltype Genitaltype
Teaching content: Growth and development stages and characteristics of each stage The factors influencing growth and development The growth and development of the craniofacial skeleton The development of tooth and occlusion Master: The characteristics of each growth period the timing and sequence of dental development growth and development stages of tooth and occlusion Familiar： Influencing factors of growth and development characteristics of growth and development of upper and lower jaw and teeth Understand：Anatomical and physiological changes in dentition and occlusion development Section 1 Stages and Characteristics 一、Stages （一）fetus period （二）neonatal period （三）infancy period （四）toddler period （五）preschool period （六）school period （七）adolescent period The relationship between the development and age Lymphoid type Neural type General type Genital type
体生 Section 2 Influencing factors of growth and development Genetic factor:Genetic variation,metabolic defects,endocrine disorders, chromosomal abnormalities More than 16,000 human genes play a role in craniofacial development. Environmental factor:Prenatal environment,postnatal environment Complex ofgenetic activity and external infuences can affect growth. Section 3 Growth and development of the craniofacial skeleton -Growth of the craniofacial skeleton origin:supporting connective tissue ofprimordial embryos osteogenic mode intramembranous ossification endochondral ossification Proportion changes of craniofacial growt and development Proportion changes volume ratio height ratio cranium face cranium face neonate 8 neonate 13 adult adult
Section 2 Influencing factors of growth and development Genetic factor: Genetic variation, metabolic defects, endocrine disorders, chromosomal abnormalities More than 16,000 human genes play a role in craniofacial development. Environmental factor : Prenatal environment, postnatal environment Complex of genetic activity and external infuences can affect growth. Section 3 Growth and development of the craniofacial skeleton 一． Growth of the craniofacial skeleton origin: supporting connective tissue of primordial embryos osteogenic mode ：intramembranous ossification endochondral ossification
Cranium growth:1-2y(rapidest development),6y(about 90%) Facial growth:1-2y,9-14y (rapidest development),Height>Depth>Width 3.Craniofacial skeleton growth and development Ist period of accelerated growth:postnatal 7m 2nd period of accelerated growth:4y-7y 3rd period of accelerated growth:1ly-13y 4thperiod of accelerated growth:16y-19y 4.Cranium growth intramembranous ossification:cranium,including forehead bone,parietal bone endochondral ossification:occipital bone,sphenoid bone,ethmoid bone. and temporal bone Bone surface hyperplasia is the main form of bone growth,one side new bone deposition and the other side old bone resorption. 5.Facial bonegrowth Three-dimensional growth ofmaxillary (length,width,height):key of facial structure Volume growth mainly depends on bone surface hyperplasia and interstitial stroma hyperplasia. Growth and development of mandible The mandible growth mainly depends on the bone surface proliferation and condylar cartilage osteogenesis. Condyle is the main growth center of mandible,it's the last one to stop developingamong the facial bones. Section 4 Development of tooth and occlusion process of tooth development time oftooth development time and sequence of tootheruption mechanism oftooth eruption succession of deciduousteeth development oftooth and occlusion
Cranium growth：1-2y ( rapidest development), 6y ( about 90%) Facial growth：1-2y，9-14y ( rapidest development), Height> Depth> Width 3.Craniofacial skeleton growth and development 1st period of accelerated growth： postnatal 7m 2nd period of accelerated growth：4y－7y 3rd period of accelerated growth：11y－13y 4th period of accelerated growth：16y－19y 4. Cranium growth intramembranous ossification： cranium, including forehead bone, parietal bone endochondral ossification： occipital bone,sphenoid bone, ethmoid bone, and temporal bone Bone surface hyperplasia is the main form of bone growth, one side new bone deposition and the other side old bone resorption. 5. Facial bone growth Three-dimensional growth of maxillary （length、width、height）： key of facial structure Volume growth mainly depends on bone surface hyperplasia and interstitial stroma hyperplasia . Growth and development of mandible The mandible growth mainly depends on the bone surface proliferation and condylar cartilage osteogenesis. Condyle is the main growth center of mandible, it's the last one to stop developing among the facial bones. Section 4 Development of tooth and occlusion process of tooth development time of tooth development time and sequence of tooth eruption mechanism of tooth eruption succession of deciduous teeth development of tooth and occlusion
It's about 20 years,including dental germs development,tooth eruption and occlusion establishment. Process of tooth development Dental germs formation (Growth) Dental tissue formation (Calcification) Tootheruption (Eruption) Tooth eruption:pre-eruptive phase eruption phase post-eruptive phase Active eruption:The teeth move towards occlusion and erupt to mouth. Passive eruption:The reduced enamel epithelium separated from the enamel surface,the gums recoiled toward the root,and the clinical crown exposed. Root development: Deciduous teeth need 1-1.5years Permanent teeth need 2-3 years(anterior teeth)/3-5 years(posterior teeth) 二，The time of tooth development Deciduous tooth germ from the 6th week to 10th week ofembryo Permanent tooth germ:from 4 months to 4 years ofage The rule of tootheruption:Certaintime,Certainorder,Left-right symmetrical eruption,Mandibular is earlier than the maxillary. The order oftootheruption is moreclinically significant than thetime of tootheruption. Thereare large individual differences in the timing of tootheruption Influencing factors:genetic factors,environmental factors The order oftootheruptionalso frequently mutates
It's about 20 years, including dental germs development, tooth eruption and occlusion establishment. Process of tooth development Dental germs formation（Growth) Dental tissue formation（Calcification) Tooth eruption（Eruption) Tooth eruption：pre-eruptive phase ；eruption phase ；post-eruptive phase Active eruption：The teeth move towards occlusion and erupt to mouth. Passive eruption：The reduced enamel epithelium separated from the enamel surface, the gums recoiled toward the root, and the clinical crown exposed. Root development : Deciduous teeth need 1 -1 .5years Permanent teeth need 2-3 years (anterior teeth) / 3-5 years (posterior teeth) 二 .The time of tooth development Deciduous tooth germ ：from the 6thweek to 10th week of embryo Permanent tooth germ: from 4 months to 4 years of age. The rule of tooth eruption:Certain time，Certain order，Left-right symmetrical eruption，Mandibular is earlier than the maxillary. The order of tooth eruption is more clinically significant than the time of tooth eruption. There are large individual differences in the timing of tooth eruption. Influencing factors: genetic factors, environmental factors The order of tooth eruption also frequently mutates
Eruption period A:central incisor order B:lateral incisor ÷D:first molar C:canine E:second molar Time and sequence of permanenttootheruption Time and sequence of permanent tooth eruption Time and sequence upper jaw jaw time (year)order time (year)order 1 78 5 67 3 2 89 6 7~8 3 11~12 12 910 4 10~11 8 10~12 9 5 10~12 10 11-12 11 6 6、✉7 67 12~13 14 11~13 13 8 1721 1721 great differences among individuals Order oferuption: Maxillary: 61243578 61245378 Mandible: 61234578 Difference 61243578 Root Sorptionofthe Primary Teeth Physiological absorption Pathological absorption Root absorption site: Deciduous anterior teeth:lingual sideofapex 1/3 Deciduousmolars:inner surface ofroot divisions
Time and sequence of permanent tooth eruption great differences among individuals Order of eruption： Maxillary: 6 1 2 4 3 5 7 8 6 1 2 4 5 3 7 8 Mandible: 6 1 2 3 4 5 7 8 Difference ： 6 1 2 4 3 5 7 8 Root Sorption of the Primary Teeth Physiological absorption Pathological absorption Root absorption site: Deciduous anterior teeth: lingual side of apex 1/3 Deciduous molars: inner surface of root divisions
Root stabilizationofdeciduous teeth: A:2-4 years old B:2-5 years old C:4-7 yearsold D:3-8yearsold E:3-8岁 Mechanism of tooth eruption (1)Biological behavior ofteeth The function ofthe dental sac Occurrence of bone resorption The role of cells (2)Molecular mechanism oftooth eruption Molecules related to tooth eruptionand its mechanismofaction tooth eruption-related molecular gene localization Replacement of deciduous and permanent teeth Deciduous tooth replacement is a complex biological proces The deciduous and permanent teeth grow in the same bone lacuna. The permanent tooth germ moves towards the occlusal surface in the jaw A.Dentition and occlusal development (1)Three dentition stages in childhood Primary Dentition 6 months-6 years old Mixed Dentition 6 years old-12 years old Young permanent dentition: 12 years old-15 years old 1.Primary Dentition Primary Dentition 6 months -6 years old Masticatory function Induction oferuption position ofpermanent teeth learning pronunciation Maintain facial beauty Prevention ofmalocclusionofpermanentteeth Major tasks in deciduous dentition:Maintain the health of deciduous teeth and the integrity ofdentition (1)Strengtheningoral health education
Root stabilization of deciduous teeth: A：2-4 years old B：2-5 years old C：4-7 years old D：3-8 years old E： 3-8岁 四. Mechanism of tooth eruption （1） Biological behavior of teeth The function of the dental sac Occurrence of bone resorption The role of cells （2） Molecular mechanism of tooth eruption Molecules related to tooth eruption and its mechanism of action tooth eruption-related molecular gene localization 五. Replacement of deciduous and permanent teeth Deciduous tooth replacement is a complex biological process . The deciduous and permanent teeth grow in the same bone lacuna. The permanent tooth germ moves towards the occlusal surface in the jaw. 六.Dentition and occlusal development （1）Three dentition stages in childhood Primary Dentition ： 6 months—6 years old Mixed Dentition ： 6 years old —12 years old Young permanent dentition： 12 years old —15 years old 1. Primary Dentition Primary Dentition ： 6 months—6 years old Masticatory function Induction of eruption position of permanent teeth learning pronunciation Maintain facial beauty Prevention of malocclusion of permanent teeth Major tasks in deciduous dentition：Maintain the health of deciduous teeth and the integrity of dentition （1） Strengthening oral health education
(2)Early detectionand treatment ofdeciduous caries (3)Prevention of malocclusion caused by premature loss of deciduous teeth 2.Mixed Dentition Mixed Dentition 6 years old-12 years old Major tasks Prevention ofmalocclusionand early correction Induction ofnormal occlusion Early prevention and treatment ofpermanent teeth caries 3.Young permanent dentition stage Young permanent dentition stage:12-15 yearsold Major tasks: Prevention and treatment ofpermanent teeth caries and periodontal diseases Correctionofmalocclusion Save the first and second permanent molars as much as possible Dentition and occlusion development Dentition and occlusion development Hellman occlusal stage ni Comihirsen mlar npmnont moa A Completion period of eruption of second permanent mola n or nent molar Attained(完成)C:Commenced(开始)B:Between A and C(A和C之间 ()A toothless period(stage IA) A toothless period
（2）Early detection and treatment of deciduous caries （3） Prevention of malocclusion caused by premature loss of deciduous teeth 2. Mixed Dentition Mixed Dentition ： 6 years old —12 years old Major tasks ： Prevention of malocclusion and early correction Induction of normal occlusion Early prevention and treatment of permanent teeth caries 3. Young permanent dentition stage Young permanent dentition stage：12—15 years old Major tasks： Prevention and treatment of permanent teeth caries and periodontal diseases Correction of malocclusion Save the first and second permanent molars as much as possible Dentition and occlusion development （一）A toothless period (stage IA) A toothless period ：
The period from birth to the time when baby teeth begin to sprout (0~0.5 vears old) The existence of intermaxillary space The mandible has only back and forthmovement,no lateral movement. (Pre-occlusal period of deciduous teeth (IC stage) Pre-occlusal period of deciduous teeth From deciduous teeth to second deciduous molars(0.5-2.5 years old) (Deciduous tooth occlusal completion period (IIA stage) Deciduous tooth occlusal completion period:From the time when all the deciduous teeth are erupted until the permanent teeth are about to sprout (2.5~6 years old) 1.Physiological space ofdeciduous dentition-primate space,developmental space 2.The change ofdental arch 3.The end plane ofthe second deciduousmolar 4.Occlusion and wear ofdeciduous teeth 1.Physiological space of deciduous dentition: Spaced type dental arch:96% closed typedental arch:4% With the change ofage,the growth ofjaw and the space became larger Developmental space:With the development of jaw,there is a physiological space in the deciduous dentition about3-yearsod,which iscalled developmental space. Physiological space:primate space+developmental space 2.Change of the dental arch:Widening ofthe spacing between deciduous canine:Reductionofanterior arch length ofthe first deciduous molar 3.Terminal plane of second deciduous molar:In the middle occlusal position. the distal relation of the maxillary and mandibular second deciduous molars is called the terminal relation,which is regarded as the basic examination item to judge the occlusal relationship ofthe deciduous teeth. 4.The occlusion and wear Deep overbite occlusion-normal overbite occlusion-blade occlusion
The period from birth to the time when baby teeth begin to sprout (0~0.5 years old) The existence of intermaxillary space The mandible has only back and forth movement, no lateral movement. （二）Pre-occlusal period of deciduous teeth（IC stage） Pre-occlusal period of deciduous teeth ：From deciduous teeth to second deciduous molars (0.5-2.5 years old) （三）Deciduous tooth occlusal completion period（ⅡA stage） Deciduous tooth occlusal completion period：From the time when all the deciduous teeth are erupted until the permanent teeth are about to sprout (2.5~6 years old) 1．Physiological space of deciduous dentition -primate space, developmental space 2．The change of dental arch 3．The end plane of the second deciduous molar 4．Occlusion and wear of deciduous teeth 1.Physiological space of deciduous dentition： Spaced type dental arch：96% closed type dental arch：4% With the change of age, the growth of jaw and the space became larger. Developmental space：With the development of jaw, there is a physiological space in the deciduous dentition about 3-6 years old, which is called developmental space. Physiological space：primate space+ developmental space 2.Change of the dental arch：Widening of the spacing between deciduous canine；Reduction of anterior arch length of the first deciduous molar 3.Terminal plane of second deciduous molar :In the middle occlusal position, the distal relation of the maxillary and mandibular second deciduous molars is called the terminal relation, which is regarded as the basic examination item to judge the occlusal relationship of the deciduous teeth. 4.The occlusion and wear Deep overbite occlusion → normal overbite occlusion → blade occlusion
or extremely shallow overbite and overjet occlusion The occlusion ofthe anterior deciduous teeth:The crossing angle of the axes of the deciduous anterior teeth is larger than the permanent teeth,so the upper and lower teeth ofthe deciduousanteriorteeth are nearly vertical (The first permanentmolarsor incisors begin to erupt II C stage) 1).Development ofthe first permanent molar 2).The eruptionofthe first permanent molars 3).The occlusal relationship ofthe first permanent molar 4).Replacement ofincisors The establishment ofthe first permanent molar relationship:greatly increases the chew area:establishes the main support for the intermaxillary height:maintain the relationship between the upper and lower dental arch The eruption ofthe first permanent molars influencing factors 1.Development direction ofthe first permanent mola 2.Eruptionrate and the degree of development ofthe upper and lower jaw 3.Physiological spaceand type ofterminal plane in dentition. the development ofthe first permanent molar 1.Dental germ begins to form (embryonic 3-4 months) 2.Beginning calcification(at birth) 3.Completionofcrown calcification (2-3 years old) 4.Start to erupt (6-7yearsold) 5.Root development is complete (9-10 years old) (The first permanent molar eruption is completed and the permanent anterior teeth eruption (II A stage) 1.Increased distance between canines 2.Change in molar spacing 3.The dental arch grows forward 4.The maxillary permanent incisors erupt distally 5.Crowding ofthe lower incisors
or extremely shallow overbite and overjet occlusion The occlusion of the anterior deciduous teeth：The crossing angle of the axes of the deciduous anterior teeth is larger than the permanent teeth, so the upper and lower teeth of the deciduous anterior teeth are nearly vertical. （四）The first permanent molars or incisors begin to erupt （ ⅡC stage） 1）. Development of the first permanent molar 2）. The eruption of the first permanent molars 3）. The occlusal relationship of the first permanent molar 4）. Replacement of incisors The establishment of the first permanent molar relationship:greatly increases the chew area；establishes the main support for the intermaxillary height；maintain the relationship between the upper and lower dental arch The eruption of the first permanent molarsinfluencing factors ： 1.Development direction of the first permanent molar 2.Eruption rate and the degree of development of the upper and lower jaw 3.Physiological space and type of terminal plane in dentition. the development of the first permanent molar 1.Dental germ begins to form（embryonic 3-4 months） 2.Beginning calcification (at birth) 3.Completion of crown calcification （2-3 years old） 4.Start to erupt（6-7 years old） 5.Root development is complete（9-10 years old） （五）The first permanent molar eruption is completed and the permanent anterior teeth eruption（ Ⅲ A stage） 1. Increased distance between canines 2. Change in molar spacing 3. The dental arch grows forward 4. The maxillary permanent incisors erupt distally 5. Crowding of the lower incisors