The document discusses the etiology of orthodontic problems over 5 sessions. It covers various specific causes of malocclusion including disturbances in embryologic development, skeletal growth disturbances, muscle dysfunction, acromegaly and hemimandibular hypertrophy, and disturbances of dental development. Environmental influences and genetic factors are also discussed. The document examines causes in detail such as fetal alcohol syndrome, cleft lip and palate, childhood fractures of the jaw, and muscular dysfunction.
The document discusses the etiology of orthodontic problems over 5 sessions. It covers various specific causes of malocclusion including disturbances in embryologic development, skeletal growth disturbances, muscle dysfunction, acromegaly and hemimandibular hypertrophy, and disturbances of dental development. Environmental influences and genetic factors are also discussed. The document examines causes in detail such as fetal alcohol syndrome, cleft lip and palate, childhood fractures of the jaw, and muscular dysfunction.
The document discusses the etiology of orthodontic problems over 5 sessions. It covers various specific causes of malocclusion including disturbances in embryologic development, skeletal growth disturbances, muscle dysfunction, acromegaly and hemimandibular hypertrophy, and disturbances of dental development. Environmental influences and genetic factors are also discussed. The document examines causes in detail such as fetal alcohol syndrome, cleft lip and palate, childhood fractures of the jaw, and muscular dysfunction.
The document discusses the etiology of orthodontic problems over 5 sessions. It covers various specific causes of malocclusion including disturbances in embryologic development, skeletal growth disturbances, muscle dysfunction, acromegaly and hemimandibular hypertrophy, and disturbances of dental development. Environmental influences and genetic factors are also discussed. The document examines causes in detail such as fetal alcohol syndrome, cleft lip and palate, childhood fractures of the jaw, and muscular dysfunction.
Genetic Influences Environmental Influences Etiology in contemporary perspective Specific causes of malocclusion Disturbances in Embryologic Development Skeletal Growth Disturbances Muscle Dysfunction Acromegaly and Hemimandibular Hypertrophy Disturbances of Dental Development Environmental Influences
Equilibrium Theory and Development of the Dental
Occlusion Functional Influences on Dentofacial Development Etiology in contemporary perspective
Changing Views of Etiologic Possibilities
Etiology of Crowding and Malalignment Etiology of Skeletal problems Malocclusion is a developmental condition. In most instances, malocclusion and dentofacial deformity are caused, not by some pathologic process, but by moderate distortions of normal development. Etiology of malocclusion Etiological assessment of malocclusion is an important aspect in orthodontics, as the genesis of the deformity provides keys to the planning treatment. The developmental process of the dentition and craniofacial growth takes place over a period of approximately 20 years, whereby the environment has a modeling impact on the genotype, being an integral part of the factors of heredity. Due to this interaction, it is difficult to classify the etiology of malocclusion exactly, as the causes are often multifactorial and prevent exact differentiation between endogeneously and exogeneously induced changes. Etiology of malocclusion Causes of Malocclusion
Cause time tissue results
1.Heredity 2.Anomalies due to 1. Neuromuscular tissue maldevelopment 1.Continual,intermitent, 2.Teeth 1.Malfunction 3.Trauma or only once 3.Bone 4.Physical agents 2.Malocclusion 2.Various age levels(pre- 4.Cartilage 5.Habits or postnatal) 3.Bone dysplasia 5.Soft tissue, except 6.Diseases muscles 7.Malnutrition Specific Causes of Malocclusion Specific causes of malocclusion Disturbances in Embryologic Development Skeletal Growth Disturbances Muscle Dysfunction Acromegaly and Hemimandibular Hypertrophy Disturbances of Dental Development Disturbances in Embryologic Development(Developmental Damage)
Those malocclusions which, etiologically speaking, were
caused by developmental damage during the fetal period, are considered Congenital Anomalies . (Moss 1962, Enlow 1982) Congenital anomalies In many of these cases the exact casual pathogenesis cannot be determined. The following are included among the causes of these dysplasia proven to date: Embryopathies caused by virus diseases in the mother(e.g. measles, toxoplasmosis, rubella ) Ionizing radiation Poisonous effects (e.g. medication) or other teratogenic harmful substances. Congenital anomalies Fetal damages with this type of genesis and the following craniofacial abnormalities have been proven to be closely connected with one another: Maldevelopment of the first and second branchial arches Micrognathism Oligodontia Anodontia Congenital anomalies The majority of cases with lip-jaw-palate clefts are included in this etiological group.
Hereditary embryonal defects only account for
approximately 20% of these patients. (Schilli et al., 1970) Disturbances in Embryologic Development Stage Time (humans) Related Syndromes Post fertilization Germ layer formation and Day 17 Fetal alcohol Syndrome (FAS) initial organization of structures Neural Tube formation Days 18-23 Anencephaly Origin, migration, and Days 19- 28 Hemifacial microsomia interaction of cell Mandibulofacial dysostosis populations (Treacher Collins syndrome) Limb abnormalities Formation of organ systems Primary palate Days 28-38 Cleft lip and/ palate, other facial clefts Secondary palate Days 42-45 Cleft Palate Final differentiation of Day 50 - birth Achondroplasia Tissues Synostosis syndromes (Crousons,Apert,s, etc.) Fetal alcohol syndrome Fetal alcohol Syndrome Lip and Palate Cleft Median Mandibular Cleft Median Mandibular Cleft Median Mandibular Cleft Crousons disease(Craniofacial dysostosis) Hemifacial Microsomia Hemifacial Microsomia Teratogens affecting Dentofacial Development Teratogens Effect Aminopterin Anencephaly Aspirin Cleft lip and palate Cigarette smoke(hypoxia) Cleft lip and palate Cytomegalovirus Microcephaly, hydrocephaly, microphthalmia Dilantin Cleft lip and palate Ethyl alcohol Central mid-face deficiency 6-Mercaptopurine Cleft Palate 13-cis Retinoic acid Retinoic acid syndrome: malformations virtually same as (Accutane) hemifacial microsomia,Treacher Collins syndrome Rubella virus Microcephaly, hydrocephaly, microphthalmia Thalidomide Malformations similar to hemifacial microsomia,Treacher Collins syndrome Toxoplasma Microcephaly, hydrocephaly, microphthalmia X-radiation Microcephaly Valium Cleft lip and palate Vitamin D excess Premature suture closure Skeletal Growth Disturbances
Fetal molding and birth injuries
Intrauterine molding Birth trauma to mandible Childhood fractures of the jaw Intrauterine molding
Arm pressed across the face Severe maxillary
deficiency at birth Head flexed tightly against the chest Pierre Robin anomalad or sequence (1/3 Stickler syndrome) Pierre Robin Syndrome Birth trauma to mandible I Heavy pressure to TMJ Internal hemorrhage, loss of tissue, under development of the mandible. It is rare and children with deformities involving the mandible are much more likely to have a congenital syndrome. Childhood Fractures of the jaw 75% of the children with early fractures of the mandibular condylar process have normal mandibular growth. When problem arise it usually is asymmetric growth with the previously injured side lagging behind. 5% severe mandibular deficiency is due to early fracture of the jaw.(Dentofacial Clinic university of North Carolina) Problem arises when there is enough scarring in the area to restrict the normal growth movements of maxilla and mandible. Ankylosis of TMJ Ankylosis of TMJ Childhood Fractures of the jaw The best therapy is conservative management at the time of injury and early mobilization of the jaw to minimize any restriction on movement. An old fracture is the most likely cause of asymmetric mandibular deficiency in a child but it might be due to rheumatoid arthritis or congenital absence of tissue as in hemifacial microsomia. Muscle Dysfunction Torticollis Major decrease in tonic muscle activity Muscular dystrophy Cerebral palsy Muscle weakness syndromes Muscular Dysfunction Acromegaly and Hemimandibular Hypertropy Acromegaly Anterior Pituitary tumor Hemimandibular Hypertropy Likley in girls between 15-20 Condylar hyperplasia prominent Possible onset from age of 10 in either sex Any Questions?