Ortho Flashcards
What incisor relationship is this?
Class I
What type of tooth movement is this?
Torque
What is a class II molar relationship?
the buccal groove of the mandibular first permanent molar occludes anteriorly to the mesio-buccal cusp of the maxillary first permanent molar
What is the average MMPA?
27 degrees
What does 5p mean on IOTN?
Cleft lip/palate
What are the different types of springs in removable orthodontic appliances?
● palatal finger springs
● buccal canine retractors
● z springs (incisors)
● t springs (premolars)
What is the baseplate of removable orthodontic appliances made from?
Acrylic
What is the Sella (S)?
the point in the midpoint of the sella turcica
What is the gonion (Go)?
the constructed point of intersection of the tangents of the ramus plane and the mandibular plane. This is the most posterior and inferior part on the angle of the mandible
What does the SNA angle show?
Indicates the relative antero-posterior positioning of the maxilla in relation to the cranial base
What does frankfort mandibular plane angle (FMPA) measure?
Growth of the mandible. The angle is the point at which the line of the mandible meets the facial plane (line that goes through the ear canal
What space requirement means orthodontic extractions will be necessary?
More than 8mm space required
What is the B point on a lat ceph?
deepest concavity on the mandibular symphysis (can change with growth and tooth movement)
What incisor relationship is this?
Class II div 1
How often do aligners need to be worn?
22 hours a day
What class skeletal pattern does this patient have?
Class II
What are the main medical contraindications for orthodontic treatment?(5)
● Risk of infective endocarditis
● Asthma (bring inhaler to apt)
● Allergies (latex and nickel)
● Bleeding disorders (complications with orthodontic extractions)
● Epilepsy (damage to appliance and Phenytoin can cause gingival hyperplasia)
What does a 5h IOTN score mean?
Two or more teeth missing from one quadant
What are the two main active components used in removable ortho appliances?
Screws and springs
What kind of bite is this?
Scissors bite
What does 3f mean on IOTN?
Deep/complete overbite but no trauma
What is a class II div 2 incisor relationship?
Lower incisor edges occlude behind the cingulum plateau of the uppers and the upper incisors are retroclined
What is average FMPA?
If the FMPA goes through the base of the head (occipital bone), it is is average
What is the average incisor inclination for maxillary incisors (line through incisors and intersect with ANS-PNS line)?
110 degrees
What type of tooth movement is this?
Pure tipping
What wire is used for southend clasps?
0.6-0.7mm
What does 4c mean on the IOTN scale?
crossbite with mandibular displacement>2mm
What does it mean if the MMPA is greater than 27 degrees?
Indicates vertical bone growth
What does it mean if the SNB angle is less than 80 degrees?
Retrognathic mandible
What is the treatment for retained deciduous theeth?
These teeth usually require extraction if it is due to ankylosis as this can deflect the permanent successor. If the permanent successor is missing, the tooth is often left in situ
What does IOTN stand for?
Index of Orthodontic Treatment Need
What growth phase does a patient need to be in for a functional appliance?
Pre-adolescent (younger than 14 years)
What type of tooth movement is this?
Translation
What does it mean if the ANB angle is greater than 2 degrees?
Class II skeletal pattern
What does it mean if the incisor inclination angle is less than 110 in maxillary or 90 in mandibular incisors?
Incisors are retroclined
What does the S-N line on a lateral ceph show?
Cranial base
What does 4d mean on the IOTN scale?
Displacement (mesial of one tooth to distal of adjacent tooth) >4mm
What is the force applied on a tooth with a spring in a removable orthodontic appliance?
Does not exceed 25-40 grams per tooth
What does 4f IOTN mean?
Traumatic overbite
Why do springs in removable orthodontic appliances need to be close to the gingival margin?
To prevent over-tipping of the teeth
What is the average incisor inclination for mandibular incisors (line through incisors and intersect with Me-Go line)?
90 degrees
When is crowding mild?
When it is 0-4mm (distal from one tooth to mesial of adjacent tooth)
What does it mean if the MMPA is less than 27 degrees?
Indicates horizontal bone growth
What is a class I incisor relationship?
Lower incisor edges occlude on the cingulum plateau of the uppers
What does 3d mean on the IOTN scale?
Displacement (mesial of one tooth to distal of adjacent tooth) between 2-4mm
What is the closed exposure technique for impacted canines?
Gold chain (expose the tooth, place bracket and gold chain and force eruption)
What is the average ANB angle?
2 degrees
What is the A point on a lateral ceph?
deepest midline concavity on the anterior maxilla (can change with growth and tooth movement)