10. Transverse
malocclusion
2. Scissor bite (also called lingual crossbite):
It is the malocclusion where the lower posterior teeth completely occlude lingual
to the upper posterior teeth.
11. Anterior crossbite
affect around 3% of US population.
Can affect one or more anterior teeth
The more the teeth in crossbite, the greater the chance of
skeletal discrepancy.
12. Anterior crossbite
Possible causes are:
Lack of space
Platally displaced upper incisor due to
retained deciduous tooth, supernumerary
tooth, trauma or pathology)
Anterior displacement of the mandible.
Skeletal problem.
13. Consequence of cross bite
TMJ problem, specially if
associated with displacement
Periodontal breakdown
(e.g. to lower incisor).
Esthetic concern (in case of
anterior crossbite)
14. Treatment
The success of correction depend on
Adequate space within the arch.
Adequate overbite.
15. Treatment options
Single tooth crossbite:
Tongue blade
Removable appliance with Z spring
Inclined bite plate
Fixed appliance
38. Posterior crossbite
Can be unilateral or
bilateral
Can affect one or more
buccal segment teeth
Often associated with
mandibular displacement
39. Incidence of posterior crossbite
Affect 8-16 % of the population
Foster & Hamilton 1969
No differance between gender and races
80% assosciated with mandibular
displacement
40. Posterior crossbite
Posterior crossbites have six possible
explanations:
(1) The upper arch is too narrow
(2) the lower arch is too wide
(3) a lateral functional shift occurs during closure of the
mandible
(4) one or more teeth are displaced toward the palate in the
maxillary alveolar ridge
(5) one or more teeth are displaced toward the buccal side of
the mandibular alveolar ridge
(6) combinations of the above explanations.
42. Etiology
Skeletal factors:
Due purely to a mismatch in the relative widths of the
arches (i.e. small maxilla, wide mandible or both).
Due to an anterior-posterior discrepancy resulting in
relative cross bite.
True skeletal asymmetry (hemimandibular
elongation, …….).
43. Etiology
Dental factors:
Palatally displaced upper buccal segment teeth
and/or lingually displaced lower buccal segment teeth.
High cusp canine or occlusal interference that result
in mandibular displacement
Improper restoration (e.g. overfilled restoration or
improper crwon design) that result in displacement.
44. Etiology
Soft tissue factors:
Microglossia (small tonuge size)
Enlarged adenoid that result in low tongue position.
Improper restoration (e.g. overfilled restoration or
improper crwon design) that result in displacement.
47. Treatment options
Treatment will depend on:
The nature of the problem (skeletal or dental)
The age of the patient
How many teeth in cross bite.
Whether displacement is present or not.
48. Treatment options
Cross elastics.
Selective grinding to remove occlusal prematurity
Dental expansion using removable plates or a
quad helix
Skeletal expansion appliances
Surgically assisted palatal expansion
62. After skeletal expansion
Following skeletal
expansion the appliance is
stabilized with for 3
months, before advancing
to the next phase of
treatment.
64. Declaration
The author wish to declare that; these presentations are his original work, all
materials and pictures collection, typing and slide design has been done by the
author.
Most of these materials has been done for undergraduate students, although
postgraduate students may find some useful basic and advanced information.
The universities title at the front page indicate where the lecture was first
presented. The author was working as a lecturer of orthodontics at Ibn Sina
University, Sudan International University, and as a Master student in Orthodontics at
University of Khartoum.
The author declare that all materials and photos in these presentations has been
collected from different textbooks, papers and online websites. These pictures are
presented here for education and demonstration purposes only. The author are not
attempting to plagiarize or reproduced unauthorized material, and the intellectual
properties of these photos belong to their original authors.
65. Declaration
As the authors reviews several textbooks, papers and other references during
preparation of these materials, it was impossible to cite every textbook and journal
article, the main textbooks that has been reviewed during preparation of these
presentations were:
Contemporary Orthodontics 5th edition; Proffit, William R, Henry W. Fields, and
David M. Sarver.
Handbook of Orthodontics. 1st edition; Cobourne, Martyn T, and Andrew T. DiBiase.
Essentials of orthodontics: Diagnosis and Treatment; Robert N. Staley, Neil T. Reske
Orthodontics: Current Principles & Techniques 5th edition; Graber, Lee W, Robert L.
Vanarsdall, and Katherine W. L. Vig
Orthodontics: The Art and Science. 3rd Edition. Bhalajhi, S.I.
66. Declaration
For the purposes of dissemination and sharing of knowledge, these
lectures were given to several colleagues and students. It were also
uploaded to SlideShare website by the author. Colleagues and students
may download, use, and modify these materials as they see fit for non-
profit purposes. The author retain the copyright of the original work.
The author wish to thank his family, teachers, colleagues and students
for their love and support throughout his career. I also wish to express
my sincere gratitude to all orthodontic pillars for their tremendous
contribution to our specialty.
Finally, the author welcome any advices and enquires through his
email address: Mohanad-07@hotmail.com