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.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
2. Contents
% Introduction
% Definition of malocclusion
% Types of malocclusion
% Classification of etiologies of malocclusion
% Brief description on various factors
% Conclusion
www.indiandentalacademy.com
3. Introduction
Comprehensive orthodontic management
involves identification of possible etiological factors and
an attempt to eliminate the same. Although it may not be
possible, it is nevertheless of value in preventive and
interceptive procedures.
Rather than having specific “CAUSES” as do
some diseases, malocclusions are usually clinically
significant variations from normal range of growth and
morphology. Etiologic factors contribute to the
variance, more often than they simply cause it
www.indiandentalacademy.com
4. Definition
The arrangement of teeth in a
dentition or their relation in the jaws to each
other, which is not according to the accepted
morphologic configuration of human maxillo-
dentofacial complex
www.indiandentalacademy.com
5. Malocclusions may involve four tissue systems
m Teeth
m Bones
m Muscles
m Nerves
Malocclusion Groups
www.indiandentalacademy.com
6. m Dental dysplasias
m Skeleto dental dysplasias
m Skeletal dysplasias
Another way to classify malocclusion is
to divide them into three groups
www.indiandentalacademy.com
7. Classification Of Etiologic Factors
According to Mc coy
T Indirect / Pre disposing causes
T Direct / Determining causes
www.indiandentalacademy.com
8. Indirect / Pre disposing causes include
T Hereditary
T Congenital defects
T Pre natal abnormalities
TAcute / chronic infections and deficiency diseases
T Metabolic disturbances
T Endocrine imbalance
T Unknown causes.
www.indiandentalacademy.com
9. Direct / Determining causes include
T Missing teeth
T Supernumerary teeth
T Transposed teeth
T Malposed teeth
T Abnormal labial frenum
T Intrauterine pressure
T Sleeping habits
T Posture
www.indiandentalacademy.com
10. T Pressure
T Abnormal muscular habits
T Malfunctioning muscles
T Premature shedding of deciduous teeth
T Tardy eruption of permanent teeth
T Prolonged retention of deciduous teeth
T Loss of permanent teeth
T Improper dental restorations
www.indiandentalacademy.com
11. ACCORDING TO MOYERS
Heredity
T Neuro muscular system
T Bone
T Teeth
T Soft parts (other than nerve and muscle)
Developmental defects of unknown origin
Trauma
T Prenatal trauma and birth injuries.
T Post natal trauma.
www.indiandentalacademy.com
12. Physical agents
T Pre natal
T Post natal
Habits
T Thumb and finger sucking, tongue
sucking, lip biting etc
Disease
T Systemic diseases
T Endocrine diseases
T Local diseases
Malnutrition
www.indiandentalacademy.com
13. According to Salzmann
Salzmann‟s diagrammatic representation of the
etiologic factors in malocclusion embodies prenatal and post natal
factors. It clearly shows the genetic, differentiative and congenital
factors that make up the prenatal elements of causation, which can
influence and one or all of the postnatal components-
developmental, functional, environmental.www.indiandentalacademy.com
14. According to Graber
General Factors
Heredity (The inherited pattern)
Congenital Defects
T Cleft palate
T Torticollis
T Cleidocranial dysostosis
T Cerebral palsy
T Syphilis etc.
www.indiandentalacademy.com
15. Environment
T Pre natal
Q Trauma
Q Maternal diet
Q Maternal metabolism
Q German measles etc.
T Post natal birth injury
Q Cerebral palsy
Q TMJ injury etc.
www.indiandentalacademy.com
16. Pre disposing metabolic climate and disease
T endocrine imbalance
T metabolic disturbances
T infectious diseases
Dietary problems
T nutritional deficiency
www.indiandentalacademy.com
17. Abnormal pressure habits and functional
aberrations
T Abnormal suckling
Q Forward mandibular posture
Q Non physiologic nursing
Q Excessive buccal pressures
www.indiandentalacademy.com
18. T Thumb and finger sucking
T Tongue thrust and tongue sucking
T Lip and nail biting
T Abnormal swallowing habits
(improper deglutition)
T Speech defects
www.indiandentalacademy.com
19. T Respiratory abnormalities
(mouth breathing)
T Tonsils and adenoids
(compensatory tongue position)
T Psychogenic tics and Bruxism
T Posture
T Trauma and Accidents
www.indiandentalacademy.com
20. Local factors
Anomalies of number
T Supernumerary teeth
T Missing teeth
Q Congenital absence or loss due to
accidents, caries etc
Anomalies of tooth size
Anomalies of tooth shape
Abnormal labial frenum, mucosal barriers
www.indiandentalacademy.com
22. ACCORDING TO PROFFIT
Specific causes
T Disturbances in embryologic development
(teratogens)
T Skeletal growth disturbances
Q Intrauterine molding
Q Birth trauma to mandible
Q Childhood fractures or the jaw
T Muscle dysfunction
www.indiandentalacademy.com
23. T Acromegaly and hemi mandibular hyper trophy
T Disturbances of dental development
Q Congenitally missing teeth
Q Malformed and supernumerary teeth
Q Interferance with eruption
Q Ectopic eruption
Q Early loss of primary teeth
Q Traumatic displacement of teeth
www.indiandentalacademy.com
24. Genetic influences
Environmental influences
T Equilibrium theory and development of dental occlusion
T Functional infuence on dento facial development.
www.indiandentalacademy.com
25. General factors
Heredity
A child may have facial features that markedly
resemble those of his father or mother, or the net result
may be a combination of features from each parent. It is
also to be noted that, a single gene is not responsible for a
particular malocclusion and it may be due to the combined
action of different types of Genes
Heredity could be considered significant in
determining the following characteristics
www.indiandentalacademy.com
26. T Tooth size
T Width and length of arch
T Height of palate
T Crowding and spacing of teeth
T Overjet
T Position and conformation of perioral musculature to
tongue size and shape
T Soft tissue peculiarities
T Facial asymmetries
T Macorgnathia and micrognathia
T Macrodontia an microdontia
www.indiandentalacademy.com
27. T Oligodontia and anodontia
T Tooth shape variations
(peg laterals, Carabellis cusps, mamelons etc)
T Cleft palate and hare lip
T Diastemas
T Deep bite
T Rotation of teeth
T Mandibular retrusion
T Mandibular prognathism
www.indiandentalacademy.com
28. Congenital defects
Cleft lip and palate
Congenital defects life cleft lip and palate separately or
in combination are among the most frequent congenital deformities of
mankind. It is not often possible for the dentist to compensate for
residual post surgical abnormalities. In a unilateral cleft, the teeth or
one side are usually in lingual cross bite with the opposing lower teeth.
Many times the premaxilla is displaced anteriorly, or, because of the
tightly repaired lip, the whole pre maxillary structure is forced
lingually. The maxillary incisors in this type are badly malposed with
bizarre axial inclinations. In the area of cleft, teeth are often jumbled.
Maxillary lateral incisors may be missing, atypical in shape or
„twinned‟
www.indiandentalacademy.com
29. Cerebral palsy
Paralysis or lack of muscular co-ordination due to an intra
cranial lesion
Complete lack of motor control resulting in abnormal
muscular function in masticaction, deglutition, speech and
respiration.
Abnormal pressure habits lead to malocclusion
www.indiandentalacademy.com
30. Torticollis
Shortening of the sternocleido mastoid muscle causing
profound changes in the bony morphology of the cranium
and the face
Characterised by “wry neck”
Bizarre facial asymmetries and uncorrectable malocclusions
if not treated early www.indiandentalacademy.com
31. Cleidocranial dysostosis
Maxillary retrusion and possible mandibular protrusion
Retained deciduous teeth
Retarded eruption of permanent teeth
Short and thin permanent teeth roots
Super numerary teeth
www.indiandentalacademy.com
33. Pre natal
Post natal
Environment
www.indiandentalacademy.com
34. Pre natal
Teratogens: Chemical and other agents capable of producing
embryologic defects if given at critical time are called teratogens
Aminopterin
Aspirin
Cigarette smoke (hypoxia)
Cytomegalovirus
Anencephaly
Cleft lip and palate
Cleft lip and palate
Microcephaly, hydrocephaly,
microphthalmia
Dilantin
Ethyl alcohol
6-Mercaptopurine
13-cis Rentinoic acid
(Accutane)
Cleft lip and palate
Central mid-face deficiency
Cleft Palate
Retinoic acid syndrome: malformations
virtually same as hemifacial microsomia,
Treacher Collins syndrome
Rubella virus
Thalidomide
Microphthalmia, cataracts, deafness
Malformations similar to hemifacial
microsomia, Treacher Collins syndrome
Toxoplasma Microcephaly, hydrocephaly,
microphthalmia
X-radiation
Valium
Vitamin D excess
Microcephaly
Cleft and palate
Premature suture closure
www.indiandentalacademy.com
35. Intrauterine molding
Pressure against the developing face prenatally can
lead to distortion of rapidly growing areas. Eg: an arm is
pressed across the face in utero resulting in severe
maxillary deficiency.
Other factors that may affect are trauma, maternal
diet, maternal metabolism and German measles
www.indiandentalacademy.com
36. Birth trauma
In some difficult births use of forceps to the head to
assist in delivary might damage either or both TMJ.
Heavy pressure in the area of TMJ could cause internal
haemorrhage, loss of tissue and a subsequent under
development of the mandible
Childhood fractures: Falls that produce condylar
fractures may cause marked facial asymmetries
Extensive scar tissue, from a burn may also produce
malocclusions
Post natal
www.indiandentalacademy.com
37. Some specific endocrinologic diseases may be potent
makers of malocclusion. Diseases with a paralytic
effect, such as poleomyelitis are capable of producing
malocclusions.
Disease with muscle malfunction, such as muscular
dystrophy and cerebral palsy also have deforming effects
on dental arch
Pre disposing metabolic climate and diseases
www.indiandentalacademy.com
39. Acromegaly
Which is caused by an anterior pituitary
tumor that secrete excess amounts of GH, excessive growth
of mandible may occur, creating a skeletal class III
malocclusion in adult life. Also multiple root resorption
may be found.
www.indiandentalacademy.com
40. Nutritional deficiency
Disturbances such as rickets, scurvy and berry-berry can
produce severe malocclusions. Main problem is upsetting of the dental
developmental time tables. The resultant premature loss, prolonged
retention, poor tissue health and abnormal eruptive paths lead to
malocclusion
www.indiandentalacademy.com
41. Non nutritive sucking habits, Includes all
sucking habits
T Thumb sucking
T Finger sucking
T Pacifiers etc.
Abnormal pressure habits and
functional aberrations
www.indiandentalacademy.com
42. Dento facial changes associated with prolonged
non nutritive sucking habits are
T Increased proclination of upper incisors
T Increased maxillary arch length
T Increased clinical crown length of max incisiors
T Increased atypical root resorption in primary
central incisors
www.indiandentalacademy.com
43. T Increased retroclination of mandibular incisors
T Increased overjet
T Decreased over bite
T Increased unilateral and bilateral class II occlusion
T Increased lip incompetence
T Tongue thrust
T Speech defects, especially lisping
www.indiandentalacademy.com
44. Lip biting
T Involves the lower lip which is turned inwards and
pressure is exerted on the lingual surfaces of
maxillary anteriors
T Proclined upper anteriors and retroclined lower
anteriors
T Hyper trophic and redundant lower lip
T Cracking of lips
Lip habits
www.indiandentalacademy.com
45. Nail biting
Does not produce gross malocclusion. But minor
local tooth irregularities like
T Rotation
T Wear of incisal edge
T Minor crowding.
www.indiandentalacademy.com
46. Tongue thrust
Defined as a condition in which the tongue makes contact with any
teeth anterior to the molars during swallowing
It has to be remembered at this time that there is a controversy
regarding Tongue thrust as an etiologic factor of anterior open bite.
According to Graber and Moyers, Tongue thrust definitely leads to
anterior open bite. Proffit contradicts this fully and according to
him, it is an already existing anterior open bite that leads to Tongue
thrusting habit
T Proclination of anterior teeth
T Anterior open bite
T Bimaxillary protrusion
T Posterior open bite in case of
lateral Tongue thrust
T Posterior cross bite
www.indiandentalacademy.com
47. Mouth breathing
Mouth breathing can result in altered jaw and tongue posture which
could alter the oro-facial equilibrium there by leading to malocclusion
T Long and narrow face
T Short and flaccid upper lip.
T Contracted upper arch with possibility of
posterior cross bite
T Increased overjet as a result of flaring of the incisors.
T Dryness of the mouth predisposes to caries.
T Anterior open bite
www.indiandentalacademy.com
48. Bruxism
Grinding of teeth for non functional purposes
T Occlusal wear facets
T Fractures of teeth and restorations
T Mobility of teeth.
T Tenderness and hypertrophy of masticatory muscles
T TMJ pain
www.indiandentalacademy.com
49. Tongue size as well as function is an important
consideration. Aglossia can result in narrowing of the
upper dental arch with severely malpositioned teeth and
crowding. Where as Macroglossia can lead to widening of
dental arches, spacing and open bite.
www.indiandentalacademy.com
50. Anomalies in number of teeth
T Super numerary teeth
T Missing teeth
Local factors
www.indiandentalacademy.com
51. Super numerary teeth
The presence of extra tooth obviously has great potential to disrupt
normal occlusal development. Early intervention and to remove it is
usually required to obtain reasonable alignment and occlusal
relationships. Most common-mesiodens.
Also lateral incisors, extra premolars, fourth molars multiple super
numerary teeth are found in cleidocranial dysplasia and other
congenital deformities like cleft lip and cleft palate
www.indiandentalacademy.com
52. Missing teeth
Congenital absence
Due to accidents / caries
Order of frequency
T Max and mandibular 3rd molars
T Max laterals
T Mandibular 2rd premolars
T Mandibular incisors
T Maxillary second premolars
Anodontia–complete absence
Oligodontia–congenital absence of many, but not all teeth
Hypodontia – absence of only a few teeth
www.indiandentalacademy.com
53. Quite frequently it has been noted
that, one maxillary lateral incisor will be of
normal size and configuration while the
other is small. Anomalies of size are
relatively frequent in the mandibular pre
molar area
Anomalies of tooth size
www.indiandentalacademy.com
54. Anomalies of Tooth Shape
Most frequent – “Peg Lateral”
Leads to excessive spacing. Anomalies of shape occur as a
result of developmental defects like amelogenesis
imperfecta, hypoplasia, Gemination, Dens in
Dente, Odontomas, Fusions, Congenital syphilitic
aberations such as Hutchinson‟s incisors and mulberry
molars.
www.indiandentalacademy.com
55. Abnormal labial Frenum
If the frenum is thick, it prevents the closure of
diastema (which is normal during mixed dentition prior to the
eruption of canines)
In these cases a frenectomy is indicated
www.indiandentalacademy.com
56. Premature loss of deciduous teeth
The early loss of permanent teeth should be
considered as a “Malocclusion Maker”
Deciduous teeth not only serve as organs of
mastication, but as space savers for permanent teeth.
Loss of a deciduous 2nd molar will lead to mesial
drift of the 1st permanent molar and blocking of
erupting 2nd premolars. In this cases appropriate
space maintainers should be given
www.indiandentalacademy.com
57. Prolonged retention and abnormal
resorption of deciduous teeth
If the roots of the deciduous teeth are not resorbed
properly, uniformly or on schedule, the permanent
successors may be either withheld from
eruption, or they may be deflected into
malposition
www.indiandentalacademy.com
58. Delayed eruption of Permanent teeth
Endocrine disorders like hypothyroidism
Presence of supernumerary teeth or
deciduous root
Mucosal or Bony barrier
www.indiandentalacademy.com
59. This is usually a secondary manifestation of a primary
disturbance
T Severe crowding
T Super numerary tooth
T Retained deciduous tooth / root fragment
T Bony barrier
T Dentigerous cysts
Another form of abnormal eruption is referred as ectopic
eruption. Most common form is a permanent tooth
erupting through the alveolar process causing resorption on
a contiguous deciduous tooth or permanent teeth , rather
than its predecessor. Eg; maxillary first molar, causing
resorption of maxillary deciduous second molar.
Abnormal eruptive path
www.indiandentalacademy.com
60. Ankylosis
Ankylosis or partial ankylosis occurs relatively frequently
during 6-12 year age period. Ankylosed deciduous teeth
should be identified and treated by removal or building up
or surgical subluxation along with space maintainers.
Permanent teeth can also be found to be ankylosed can be
due to
T Accidents / trauma
T Congenital diseases like cleidocranial dysostosis
www.indiandentalacademy.com
61. Dental caries
Dental caries should be considered as one of the local
factors causing mal occlusion. Caries which leads to
premature loss of a deciduous or permanent tooth may
cause drifting, axial inclination, over eruption, bone loss
etc.
www.indiandentalacademy.com
62. Improper dental restorations
Silver mercury alloy restorations have a tendency
to “flow” under pressure. Large proximal restorations change
gradually under the assault of occlusal forces, and arch length is
increased. This may result in the creation of broken
contacts, rotations, crossbite conditions and functional
prematurities. Lack of anatomic detail in restoration of cuspal
areas of a tooth can permit elongation of opposing tooth.
Loose contacts also leads to food packing, teeth
tend to move apart and also leads to bone loss
www.indiandentalacademy.com
63. Knowledge about the various etiological factors of malocclusion will
help us to plan the various interceptive and preventive orthodontic
procedures.
It also helps in eliminating the etiological factor if it is of a
environmental type.
The recognition and reporting of a malocclusion or a condition that
could lead to a malocclusion is the most important service that a
dentist can provide to his patients. Malocclusion has an important
impact on the function and esthetics of the entire dentition. In
fact, malocclusion has a detrimental effect on the self esteem of many
children, adolescent and adult. If a malocclusion is not recognized by
either the dentist or the patient, it cannot be assessed and treated
A sound knowledge about the various factors that lead to
malocclusion, will definitely help is to render excellent treatment for
our patients with good retention and stability
Conclusion
www.indiandentalacademy.com
64. For more details please visit
www.indiandentalacademy.com
www.indiandentalacademy.com