Buccolingual malrelationship of upper and lower teeth.Anterior or posterior (unilateral or bilateral) with or without mandibular displacement. Buccal crossbite: Lower teeth occlude buccal to corresponding upper teeth . Lingual crossbite (scissors bite): Lower teeth occlude lingual to palatal cusps of upper teeth.

2.  American association of orthodontist defines
crossbite as : An abnormal relationship of
tooth or teeth to the opposing tooth or teeth
in which normal buccolingual or labiolingual
relationships are reversed.

3.  BASED ON LOCATION
 ANT. CROSSBITE POST.CROSSBITE
NO. OF TEETH NO. OF TEETH SIDE INVOLVED
SINGLE SEGMENTAL UNILATERAL
BILATER
SINGLE SEGMENTAL TOOTH CROSSBITE -AL
TOOTH CROSSBITE CROSSBITE
CROSSBITE
TO EXTENT
.SINGLE POSTURE
. BUCCAL NON-OCCLUSION
.LINGUAL NON-OCCLUSION

4.  BASED ON ETIOLOGICAL FACTOR
CROSSBITE
SKELETAL FUNCTIONAL
CROSSBITE DENTAL CROSSBITE
CROSSBITE

7.  Etiology
 Dental factors:
trauma to primary teeth or to the permanent
tooth bud, over retained primary tooth,
supernumerary teeth, inadequate arch
length, lip biting, repaired cleft lip or palate,

8.  SKELETAL : Excessive mandibular growth,
Genetic or inherited
cleft palates where there is
retrognathic maxilla.

9.  FUNCTIONAL CROSSBITE: Due to
functional interference of mandible during
closure. This is because of premature
contact and leads to pseudo class 3
malocclusion.

10. INVOLVE SINGLE TOOTH INVOLVE SEGMENT OF
ARCH

11.  Loss of arch length as adjacent teeth
migrates
 Excessive wear to the teeth.
 Traumatic occlusion of the unlocked teeth.
 Development of pseudo-class 3
malocclusion.
 Gingival stripping on labial surface of lower
teeth.

12.  Number of teeth involved: single tooth
indicates local origin and dental crossbite.
 Location of tooth in crossbite : any deflection
from original position or inclination indicates
dental cross bite.
 Functional path of closure of mandible and
occlusal prematurities: simple occlusal
grinding may eliminate development of cross
bite.

13.  Molar and canine relationships: will be class
1 for dental crossbite in centric occlusion. In
true skeletal cross bites the molar and
canine relationship will be class 3.
 Radiographic findings: lateral cephalogram
is useful to find out skeletal discrepancy and
axial inclination of incisors.

14.  AAPD GUIDELINES FOR MANAGEMENT OF
CROSSBITE
 OBJECTIVE OF TREATMENT:
IMPROVED INTRAMAXILLARY ALIGNMENT AND
ACCEPTABLE INTERARCH OCCLUSION AND
FUNCTION.
 TREATMENT COMPLETED WITH
1.EQUILIBRATION
2.APPLIANCE THERAPY
3.EXTRACTION
4.COMBINATION
 TREATMENT DECISION DEPEND UPON
1.AMOUNT AND TYPE OF MOVEMENT
2.SPACE AVAILABLE
3.AP,TRANSVERSE& VERTICAL SKELETAL
RELATIONSHIP
4.GROWTH STATUS
5.PATIENT CO-OPERATION

15.  IN 4 STAGES
 IN PRIMARY DENTITION
 IN MIXED DENTITION
 IN PERMANENT DENTITION
 IN POST PERMANENT DENTITION

16.  Availability of mesio-distal space to correct
the locked in tooth
 Sufficient overbite
 Position of tooth
 Occlusion whether it is class 1 or 3
 Extent of root formation-light forces for teeth
with incomplete root formation.

17.  (PREVENTIVE ORTHODONTIC)
ELIMINATION OF FACTORS
E.G.
 OCCLUSAL PREMATURITIES
 SUPERNUMERARY TOOTH
 HABITS

18.  (INTERCEPTIVE ORTHODONTIC )
TREATMENT BASED ON :
 INSIOR POSITIONING AND SPACE
AVAILABLE
 STAGE OF ERUPTION
 DEGREE OF OVERBITE

19.  Correction of pseudo class 3 anterior cross
bite may require only the removal of
premature contact by incisal grinding of
maxillary or mandibualr incisors.

20.  TONGUE BLADE
Ideally suited for a case of one
tooth anterior croos bite. Lower incisor
acts a s fulcrum. Tongue blade placed 45
degree behind the locked tooth.
used for 1 to 2 hors for 10 to 14 days daily.
 INDICATIONS:
1.INCISORS STILL ERUPTING
2.ADEQUATE SPACE
3.NO MAJOR OVERBITE
 DISADVANTAGES:
1.EFFECTIVE TILL CLINICAL
CROWN NOT COMPLETELY
ERUPTED
2.PATIENT CO-OPERATION

21. Introduced by catlan. A lower acrylic inclined plane
is cemented and the plane should be at 45 degree
angle to the long axis of lower incisor teeth.
INDICATION:
Treatment of dental anterior cross bite involving one
or more teeth can be accomplished.
DISADVANTAGES:
 Difficulty in speech and chewing.
 Patient cooperation is needed.
 Possibilty of opening the bite if used for more than 2
or 3 weeks.

22.  CANNOT BE GIVEN IF
MANDIBULAR TEETH MALALLlGNED
PERIODONTICALLY COMPROMISED

23. CAN CORRECT SINGLE TOOTH
CROSSBITE
2-4 WEEKS.
NOT RECOMMENDED IN PATIENT WITH
EXESSIVE OVERBITE.

24.  Composite inclines are build on lower
mandibular incisors directly in the patients
mouth.
 Croll suggested use of bonded compomer
slope based on the assumption that
compomer can be easily removed.

25.  Maxillary hawley’s appliance with z spring
incorporated into the acrylic resin.
 Retention can be obtained by use of ball
clasps, adams or c type clasps.
 Movement of the in locked incisors is
accomplished by activating the springs 1.5 to
2mm per weeks.
 If the bite is deeper than normal then a slight
opening of the bite may be desirable by
means of a bite plane.

26.  DOUBLE CANTILEVER
SPRING/Z-SPRING
INDICATION:
WHEN INVOLVE 1-2 MAXILLARY
ANT. TEETH
DISADVANTAGES
EFFECTIVE ONLY WHEN SPACE
AVAILABLE

27.  SCREW APPLIANCE:
1.MICRO SCREW :
USED FOR SINGLE TOOTH
2.MINI SCREW :
USED FOR 2 TEETH
3.MEDIUM SCREW:
USED FOR SEGMENTAL TEETH
4.3-D SCREW
CAPABLE OF CORRECTING ANT. AND
POST. CROSSBITE

28. FACE MASK
INDICATION:
SKELETAL ANTERIOR CROSBITE

29.  FRANKEL III APPLIANCE
-SKELETAL CLASS III
MALOCCLUSION
 CHIN CAP APPLIANCE
-PREVENT OR CORRECT ANT.
CROSSBITE
DUE TO PROMINENT MANDIBLE

30. [III] IN PERMANENT DENTITION
 SCREW APPLIANCE:
MINI SCREW
MEDIUM TO CORRECT SINGLE OR
SCREW SEGMENTAL CROSSBITE
 FIXED APPLIANCE:
TO CORRECT SINGLE OR MULTIPLE TEETH
[IV] IN POST PERMANENT DENTITION:
SURGICAL ORTHODONTIST

31.  DEFINITION: a transverse discrepancy in
arch relationship in which the palatal cusps
of one or more upper posterior teeth do not
occlude in the central fossae of opposing
lower teeth.

32.  Dental factors : faulty eruption pattern,
insufficent arch length leads to lingual or
buccal deflection of teeth during eruption,
Over retained primary teeth leads to lateral
shift of mandible, ectopic eruption and
prolonged thumb sucking.

33.  Skeletal factors:
 Asymmetric growth of maxilla or mandible:
inherited growth pattern, trauma, long
standing functional problem.
 Difference in basal width of maxilla and
mandible: constricted maxilla
cleft palate

34.  Functional factors: due to functional
adjustments to tooth interferences. Muscular
adjustment is more compared to dental cross
bites. Functional analysis should be done.

35.  Abnormal wear of dentition
 Interference of normal growth and
development of arches.
 Pain due to muscle spasm.
 Asymmetric midlines.
 Loss of arch dimension

36.  Study models using wax bite in centric
occlusion.
 Normal bucal and lingual axial inclination.
 Symmetry of arches can be assessed using
boley guage or divider.
 Assessment of midlines by PA view
radiographs or frontal cephalogram.

37.  Midline should be assessed. Differential
diagnosis of midline shift is as follows:
 midline shift only in centric then functional
crossbite
 Midline shift both in centric and rest position
then true skeletal crossbite.

38.  Posterior crossbite present as any one of the
combination
lingual crossbite
buccal crossbite
complete lingual crossbite

39. SIMPLE POSTERIOR CROSSBITE
 FREQUENTLY SEEN IN
CLINICAL PRACTISE
BUCCAL CUSP OF MAXILLARY
TEETH OCCLUDE LINGUAL TO
BUCCAL CUSP OF MANDIBULAR
TEETH

40. UNILATERAL
CROSSBITE
BILATERAL
CROSSBITE

41. BUCCAL NON-
OCCLUSION
LINGUAL/PALATAL
NON-OCCLUSION

42. SKELETAL CROSSBITE
CAUSES:
1.INHERITED
2.DEFECTIVE EMBRYOLOGICAL DEVELOPMENT

43.  availabilty of mesiodistal space.
 position of apical portion of tooth after
treatment. This should be at the same
position as that of the tooth in normal
occlusion.
 Types of tooth movement movement
required either tipping or bodily movement.

44.  Usually in posterior single tooth crossbite
both the antagonist teeth are tipped out of
position.
 Bite elastics are effective in such cases.

45.  First any fuctional interfernce present is
eliminated by occlusal equlibration.
 Treatment of bilateral contraction-quad helix,
w-arch, RME.
 Treatment of unilateral cross bite-
removable plates, quad helix , w-arch and
coffin spring.

46. QUAD-HELIX APPLIANCE
:
SPRING CONSIST OF 4 HELICES
CAPABLE OF DENTOALVEOLAR
EXPANSION
OF MOLARS AS WELL AS
PREMOLAR
REGION
CAN BE REACTIVATED WITH 3
PRONG
WIRE WITHOUT REMOVAL

47.  This may be due to narrow maxilla or
mandible.
 Narrow maxilla:
mild cases-quad helix or w-arch
severe cases- RME
 narrow mandible- usually associated with
retrognathic mandible- functional appliance.
 Severe cases treated by surgery.

48.  One of the oldest appliance still used in
orthodontics.
 Broadly classified as:
Slow expansion appliance
rapid expansion appliance

49.  Designed primarily to produce dentoalveolar
changes.
 In young children might produce skeletal
changes with opening of midpalatal suture.

50.  Relieve crowding in minimal space
discrepancy (<4mm)
 Posterior dental crossbite in one or two
teeth.
 Cleft palate cases with collapsed maxilla.
 Constricted maxillary arch.

51.  Adv – slow expansion elicits more
physiological response, less damage to
teeth, produces skeletal effect in young
children.
 Disadv - movement is predominantly tipping
rather than bodily expansion.

52.  Removable slow expansion :
Expansion plates with jack screws
Coffin springs
Removable quad helix
 Fixed slow expansion:
W – arch
Quad helix
Expansion screw

53.  Orthodontic indication:
unilateral or bilateral posterior cross bite
narrow maxila in certail class 2 cases
collapsed maillary arch in cleft palate
along with reverse pull headgear to loosen
sutures.
used in anterior crossbite to gain spaces
Bonded RME can be used in high angle
cases

54.  Medical indication:
poor nasal airway, recurrent ear nasal and
sinus infection, septal deformity, allergic
rhinitis, asthama.

55.  Application of force to widen the maxilla
causes opening of midpalatal suture and
then new bone formation is induced.
 The space created in the midline is filled with
tissue fluids and blood.
 after 3 months new bone fills in the space.

56. Banded Bonded
Haas acrylic splints
Isaacson cast metal splints
Hyrax

57.  Before 15yrs:
Activate twice in a day
90 degree activation each time
0.5mm a day
Review after 1 week
15-20 yrs
Activate 4 times a day
45 degree activation
0.5mm per day

58. Opens in a ‘v’ fashion
Broad end is in anterior apex in posterior
Appearance of midline diastema
Treatment period is usually 2 weeks.
Relapse is higher hence overcorrection req
Force recorded is in range of 10 to 20 pounds.

59.  Bone changes: maxilla moves laterally due
to expansion, rotates with the fulcrum at
fronto nasal sutures, increase in nasal
airway, downward and backward rotation of
mandible, increase in mandibular angle.
 Sutural changes: after initial hyperaemia
area is invaded by osteoblasts. New bone is
deposited at the edge of palatal processes.

60.  Dental changes: initially teeth move labially
by translation. Increased buccal inclination of
posterior teeth. Slight extrusion of posterior
teeth. Appearance of median diastema which
closes later due to pull of transseptal fibers.

61.  At the end of active expansion treatment
80% skeletal & 20% dental expansion
occurs.
 Relapse is highest during first 6 weeks.
 Dissappearance of mesian diastema is due
to pull of transseptal fibers.

62.  Detection of these condition in primary
dentition can allow either intervention or
monitoring on an effective basis.
 Deciding when or even whether to treat an
orthodontic problem in primary dentition is a
controversial issue.

63.  The majority of crossbite in primary dentition
appear to be unilateral than bilateral.
 Prevalence of posterior crossbite in primary
dentition
- 1to 6% depending upon population sampled.
- -caucasian population generally exhibiting
higher prevalence than african and asian.

64.  The proportion of posterior crossbites of
primary dentition which persist in permanent
dentition varies with longitudinal studies
reporting between 55 to 90% of these
malocclusion failing to self correct beyond
primary dentition stage.

65.  Better long term stability.
 Reduction in overall treatment complexity
and time.
 Better functional and aesthetic end results.

66.  Allow time for possible spontaneous
correction of malocclusion.
 Avoid multiple phases (as a result of relapse
or other orthodontic problems which do not
manifest untill later)
 Ensure the patient has reached a
developmental stage at which cooperation
towards and self motivation for treatment is
present.

67.  Developmental : transverse discrepancy
between maxilla and mandible,
anteroposterior skeletal discrepancy, cleft
palate
 Soft tissue influence and habits: neonatal
intubation resulting in trauma to or prolonged
pressure on palate, early weaning and
associated low impact muscular activity from
bottle feeding, non nutritive sucking,
adaptive swallowing behaviour

68.  Majority of posterior crossbites in primary
occlusion do not correct by themselves.
 Orthodontic treatment is considered
desirable.
 A positive effect on factors described below.

69.  Bruxism can be triggeredby occlusal
interference and lead to significant tooth
surface loss.
 Posterior crossbites with a shift on closure
are one of the malocclusion correlated with
TMJ.
 Unilateral crossbites may result in facial
asymmetry and lower midline discrepancy.

70.  Difficulty in speech and deglutition. Defective
articulation of sounds such as ‘r’ ‘s’ and ‘l’.

71.  Only clear indication for correction in primary
dentition is in cases where aesthetics or
function is otherwise compromised.
 Depend on an intact dentition and certain
level of patient cooperation.

72.  Correct any habit that has contributed to the
aetiology of crossbite or monitor for
spontaneous correction.
 Remove tooth interferences or generate
cuspal guidance that prevents the patient
from biting into functional crossbite.
 Actively expand a constricted maxillary arch
using one of several removable or fixed
appliance.

73.  With upto 45% of posterior crossbites in the
primary dentition self correcting with
continued development of the dentition there
is no evidence at present time to support the
routine correction of crossbites in primary
dentition.

74.  CROSSBITE SHOULD BE CONSIDERED IN
THE CONTEXT OF PATIENT’S TOTAL
TREATMENT NEEDS:
 CROSSBITE CORRECTION
1.REDUCE DENTAL ATTRITION
2.IMPROVE DENTAL ESTHETICS
3.REDIRECT SKELETAL GROWTH
4.IMPROVE TOOTH TO ALVEOLUS
RELATIONSHIP
5.INCREASE ARCH PERIMETER