ORTHODONTOLOGY Flashcards
Given the side view of the 12-year old patient, and a left and a right photograph of the upper and lower orthodontic casts.
a. Describe the molar (left and right), canine (left and right) and incisor relationship. (5)
molar: class III canine: class III or I?
incisor: class II
Given the side view of the 12-year old patient, and a left and a right photograph of the upper and lower orthodontic casts.
b. What type of malocclusion is it? (2)
Class II division 1, increased overjet
Given the side view of the 12-year old patient, and a left and a right photograph of the upper and lower orthodontic casts.
c. List 4 reasons causing this malocclusion. (4)
biting on lower lip
mismatching development of mandible and maxilla (mandibular being slower)
long cranial base
large cranial base angle
genetics
Given the side view of the 12-year old patient, and a left and a right photograph of the upper and lower orthodontic casts.
d. 4 ways to measure craniofacial development (4)
Ask them about secondary sexual characteristics, e.g. when has their voice
deepened (boys), when has menarchy first started (girls)
Hand-wrist X-ray
Lateral cephalometic radiograph
Height
Given the side view of the 12-year old patient, and a left and a right photograph of the upper and lower orthodontic casts.
e. List 5 implications associated with malocclusion(not limit to this case). (5)
Given the side view of the 12-year old patient, and a left and a right photograph of the upper and lower orthodontic casts.
f. What is “mesiodens”? Where is it commonly located? List the cause. (3)
- Definition:
- Supernumerary teeth that develops between the central incisors.
- Commonly located:
- Between the maxillary central incisors
- Causes
- Cleft Lip and Palate
- Cleidocranial Dysostosis
- Gardner’s Syndrome
Given the side view of the 12-year old patient, and a left and a right photograph of the upper and lower orthodontic casts.
g. Treatment of mesiodens (2)
Two treatment options: Extraction or Observation
- Extraction
- Immediate removal of mesiodens is usually indicated in the following situations:
- Inhibition or delay of eruption
- Displacement of the adjacent tooth
- Interference with orthodontic appliances
- Presence of pathologic condition
- Spontaneous eruption of the supernumerary tooth.
- Immediate removal of mesiodens is usually indicated in the following situations:
- There are two methods for extraction of mesiodens
- Early extraction before root formation of the permanent incisors
- Late extraction after root formation of the permanent incisors.
- The immediate removal versus delay in surgical intervention following root development of the central incisor and the lateral incisor about the age of eight to 10 years has been mentioned
- Some authors recommend extraction of mesiodens in the early mixed dentition in order to facilitate spontaneous eruption and alignment of the incisors.
- In order to promote eruption and proper alignment of adjacent teeth, it is recommended to extract mesiodens in the early mixed dentition, which may reduce the need for orthodontic treatment. It might take six months to three years for an unerupted tooth to erupt after removal of the mesiodens
- Delayed extraction of the mesiodens about the age of 10 when the apex of the central incisor nearly forms. If treatment is postponed after this age, more complex surgical and orthodontic treatment may be necessary.
Monitor
- Monitoring of mesiodens in the following situations; satisfactory eruption of the succeeding teeth, absence of any associated pathologic lesions and risk of damage to the vitality of the related teeth.
Given lateral cephalometric analysis of the patient, panoramic radiograph and a periodical radiograph of 53.
14 year old male, seeking treatment for the missing tooth.
a. What is orthodontics extraoral examination? (6 marks)
b. Describe the occlusal relationship (molars, canines, incisors)
Angle’s Class 1?
Class 1?
British xxx Class 1?
Given lateral cephalometric analysis of the patient, panoramic radiograph and a periodical radiograph of 53.
14 year old male, seeking treatment for the missing tooth.
c. Pathology found on the Panoramic Radiograph?
Pathology found on the periapical radiograph
How does the Pathology impact on the mixed dentition
Anson: No answers given
- Orthodontics: Patient with mixed dentition (photos and study casts) (Formative, 2005) a. Provide orthodontic diagnosis
E/O MMPA, LFH, Mandible, Maxilla, TMJ
I/O A P, VERTICAL, TRANSVERSE, OH, Pathology
SOFT TISSUE lip competence, nasolabial angle, labiomental fold
- Name five ways to relieve crowding and create space (Formative, 2005)
Extraction
Distalization of molars
Arch expansion
Proclination of incisors / moving teeth forward
Interproximal enamel stripping
- Ortho: 17 year old female (incompetent lips, skeletal class II div 1). Given: clinical & I/O photos, lateral cephalometric radiograph, computer analysis of lat ceph. (Summative, 2005)
a. Write down the extra oral features of this patient.
Convex profile
Incompetent lips
LFH
MMPA
Facial symmetry
Midline
- Ortho: 17 year old female (incompetent lips, skeletal class II div 1). Given: clinical & I/O photos, lateral cephalometric radiograph, computer analysis of lat ceph. (Summative, 2005)
b. Write down the intraoral features of this patient.
Incisor class II division I
Increased OJ
OB
Midline
Missing teeth
Extra teeth
Molar relationship
Canine relationship
Crowding? Spacing?
Crossbite?
- Ortho: 17 year old female (incompetent lips, skeletal class II div 1). Given: clinical & I/O photos, lateral cephalometric radiograph, computer analysis of lat ceph. (Summative, 2005)
c. List two different methods to improve the lip function and reduce the overjet of this patient.
Normalize overjet of patient by: extraction of upper 4 and lower 5
Retrocline the UI so that the lips will be competent and have more control
Procline LI
Surgery to correct underlying skeletal pattern
- Ortho: 17 year old female (incompetent lips, skeletal class II div 1). Given: clinical & I/O photos, lateral cephalometric radiograph, computer analysis of lat ceph. (Summative, 2005)
d. Sometimes anchorage with headgear is required. What are the three types of pulls using headgear?
High pull
Horizontal pull
Cervical pull
- Ortho: 17 year old female (incompetent lips, skeletal class II div 1). Given: clinical & I/O photos, lateral cephalometric radiograph, computer analysis of lat ceph. (Summative, 2005)
e. List two commonly used upper and two lower retainers.
Vacuum formed retainer
Bonded retainer
- Ortho: 9 year old, incompetent lips, affect speech (Summative, 2005)
a. What are the effects of thumb sucking on maxillary development?
- Proclination of maxillary incisors
- Anterior open bite
- Restriction of incisors development and height of maxillary anterior alveolar process
- Negative pressure making upper arch narrow
- Taper arch shape (constricted)
- Skeletal posterior crossbite
- Ortho: 9 year old, incompetent lips, affect speech (Summative, 2005)
b. Write down two beneficial effects of using a headgear activator.
Stimulate growth of retrognathic mandible
Inhibit growth of maxilla
- Ortho: 9 year old, incompetent lips, affect speech (Summative, 2005)
c. List three methods of assessing skeletal maturity.
- Hand wrist radiograph
- Lateral cephalometric tracing
- Average annual growth incremental are read off to predict the change in position of cephalometric landmarks
- Assessment of height and secondary sex characteristics
- (Cervical vertebrae radiograph)
- Gain in height in previous year
- Ortho: 9 year old, incompetent lips, affect speech (Summative, 2005)
d. List three ways in which the patient can achieve an anterior oral seal.
Circumferential muscular activity to achieve lip to lip seal
Mandible is postured forwards to allow the lips to meet at rest
Lower lip is drawn up behind the upper incisors
Tongue is placed forward between the incisors to contact the lower lips (often contribute to development of incomplete overbite)
- Ortho: 9 year old, incompetent lips, affect speech (Summative, 2005)
e. What are the mandibular growth rotations associated with: 1.ClassIIdiv1; 2.ClassII div2?
Class II dis 1: with increased OB, Forward rotation; with decreased OB, backward rotation
Class II dis 2: Forward rotation
- Ortho: age = 9; study casts, lateral ceph tracing; anterior crossbite (Summative, 2007)
a. Problem list (5)
b. What is BSI classification for the incisors?
- Based on incisor relationship and is the most widely used descriptive classification (qualitative)
- Class I the lower incisor edges occlude with or lie immediately below the cingulum plateau of upper central incisor
- Class II the lower incisor edges lie posterior to the cingulum plateau of upper central incisor
- Division 1 proclined upper central incisors, or increase in overjet
- Division 2 retroclined upper central incisors, minimum or increased overjet
- Class III the lower incisal edge lie anterior to the cingulum plateau of the upper central incisors, with reduced or reversed overjet
- Ortho: age = 9; study casts, lateral ceph tracing; anterior crossbite (Summative, 2007)
c. History taken for this type of malocclusion
Crowding of upper arch (premature loss of deciduous teeth)
Trauma or pathology
Familial pattern
Mandibular displacement
- Ortho: age = 9; study casts, lateral ceph tracing; anterior crossbite (Summative, 2007)
d. Mixed dentition analysis for Caucasians (5)
- Ortho: age = 9; study casts, lateral ceph tracing; anterior crossbite (Summative, 2007)
e. 3 main causes of median diastema
Supernumerary teeth / high frenum attachment / missing or peg shaped laterals
Actually it is normal during the ugly duckling stage as eruption of canine cause tipping movement of central incisors , self-closure occur if space is small
- Ortho: age = 9; study casts, lateral ceph tracing; anterior crossbite (Summative, 2007)
f. What consideration needed concerning retention after correction of median diastema?
Relapse if space distal to central incisors has not been closed
Re migration of frenum attachment after frenectomy
Bonded flexible wire can be attached to palatal sides of two central incisors to prevent space reopen
- Ortho: age = 9; study casts, lateral ceph tracing; anterior crossbite (Summative, 2007)
g. Name the stage of treatment provided
Retention stage (Orthodontic treatment involve 3 stages: planning > active > retention)
- Ortho: 11 year old, class 2 div. 1 (Summative, 2007)
a. Patient needs growth modification. What appliance needed and its 4 modes of action? (5)
Functional appliance (Herbst appliance or Cervical pull headgear with Andresen activator)
Restrict growth of maxilla / promote growth of mandible / dentoalveolar change / remodeling or
condylar growth/ clockwise rotation of occlusal plane/ extrusion of upper molars to decrease OB
- Ortho: 11 year old, class 2 div. 1 (Summative, 2007)
b. If patient rejects this treatment, what other ways? (2)
Accept malocclusion
Functional appliance: twin block
Orthodontic camouflage
Orthognatic surgery in future after growth of jaw is completed
- Ortho: 11 year old, class 2 div. 1 (Summative, 2007)
c. 3 accessory orthodontic appliances for effective control of ↓overjet
2 by 4 appliance
Z spring
- Ortho: 11 year old, class 2 div. 1 (Summative, 2007)
d. Name the term for this patient’s overbite
Deep bite (when incisors’ overlap exceeds 1/3 of crown height of lower
- Ortho: 11 year old, class 2 div. 1 (Summative, 2007)
e. 2 fixed appliances to expand maxilla (4)
Rapid maxillary expansion appliance
Quadhelix appliance
- Ortho: 11 year old, class 2 div. 1 (Summative, 2007)
f. Treatment options for questionable 26 occlusal caries
Topical fluoride / preventive resin restoration / caries restoration
- Ortho: 11 year old, class 2 div. 1 (Summative, 2007)
g. What topical fluoride regime for this patient?
Fluoride varnish (22600 ppm 5% NaF) ?
a. List out the extra oral orthodontic diagnosis. (5)
see question 10a on page 193-195
b. List out the intra oral orthodontic diagnosis. (5)
See Question 15b
page 209-210
c. Write down the formula for “Facial proportion” and calculate it with the data obtained from cephalometric analysis. (2)
The facial Proportion
This is the ratio of the lower facial height to the total anterior facial height measured perpendicularly from the maxillary plane, calculated as apercentage
d. What are the other measurements that indicate the vertical skeletal patterns? (2)
- Maxillary Mandibular plane angle (MMPA)
- Average is 27 + 4 degree
- Frankfort Mandibular plane angle (FMPA)
- Average is 28 + 4 degree
- Difficult to locate accurately than MMPA so not preferred
- Increased angle indicate either an increased lower anterior face height or reduced lower posterior face height
e. What is the reference line for wits analysis? (1)
Functional occlusal plane (between cusp tips of molars and premolars / primary molar)
f. What are the two factors that we should consider when making space analysis? (2)
Nationality and gender if we were to use tanaka’s space analysis method
g. What are the three aspects of etiology for the malocclusion regarding to the information
provided? (3)
Skeletal factors: retrognatic maxilla with normal mandible / normal maxilla with prognathic mandible Backward rotation of mandibular growth
Soft tissue factors: tongue thrusting habit
h. What are the 5 methods for creating space to relieve crowding? (5)
- Extraction of teeth
- Factors to consider – prognosis of tooth, position of tooth, space analysis, incisor relationship, lateral facial profile, anchorage required, types of appliances to be used
- Extract incisor – rare, as it will cause lingual tilting of remaining lower labial segment + reduction of inter-canine width
- Extract canine – rare (only when severely displace or crowded canine case) as its position is at turning point of arch which provides canine guidance + its long root is favorable for anchorage
- Extract PM1 – common method to relieve moderate to severe crowding in arch
- Extract PM2 – indicated in mild to moderate crowding cases with
- hypoplastic PM2 (poor bracket bonding)
- severe displacement of PM2 itself
- space closure by forward mvt of M1 instead of labial segment retraction is wanted
- Extract M2 – in cases you want to facilitate distal mvt of buccal segment / relieve mild premolar crowding / provide additional space for third molar eruption
- Arch expansion (make sure there is adequate buccal supporting bone before starting)
- Removable appliances with midline screw and buccal capping
- Rapid maxillary expansion (RME)
- Large forced generated to open the midline suture of palate to achieve skeletal expansion
- Used in teens (10-11 years old) with midline suture not yet fused
- 0.25mm expansion on arch per day
- 2-time adjustment needed per day
- left in mouth as retainer for few months later
- not stable, can cause transverse problems
- usually for cases together with CB or OB
- Proclination of incisors
- Distalization of molars
- Functional appliance (rare) – E/O force by headgear
- Removable appliance – screw appliance
- Fixed appliance (usually for lower) – with spring
- Enamel stripping –1-2mm enamel removal only
- beware of dentine exposure + apply F- after stripping
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
a. What are your extra oral diagnoses in the sagittal dimension of this case? (5)
Average MPA & facial proportions
Slightly acute nasio labial angle
Anson: More on pages 193-195
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
b. What type of growth pattern does this patient have? (2)
Backward downward
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
c. What type of appliance is suitable for correction of her malocclusion? (1)
Functional appliance
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
d. Give an example of this type of appliance. (1)
Twin block appliance / Herbst appliance / Bionator / Van beek high pull headgear / Andresen activator
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
e. State two desirable actions that this type of appliance can achieve. (2)
e. State two desirable actions that this type of appliance can achieve. (2)
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
f. Which method of space analysis is the best for this case? (1)
Tanaka Johnston mixed dentition analysis
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
g. What measurements do you need for the space analysis? (3)
Sum of mesiodistal width of lower 4 incisors → Calculate predicted width of unerupted canine and premolars
Arch length from distal aspect of permanent lateral incisors to mesial aspect of permanent first molar → Space available
Differences between space available and required = spacing / crowding
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
h. After space analysis, you found out that there is spacing in the upper arch, but you can’t find any spaces from the study cast, why? (2)
Individual variation among populations
Errors in measuring width of lower incisors when they are crowding or overlapped
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
i. State three methods to assess her skeletal maturity. (3)
- Direct method
- Longitudinal records of cephalograms
- Indirect method
- Chronological age
- Height increase (peak growth velocity)
- Secondary sex characters
- Hand-wrist X rays
- Cervical Vertebral Maturation (CVM)
Anson: More on pages 197-199
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
j. If an adult patient has exactly the same malocclusion, then what is your best treatment option? What disciplines would be involved in this treatment option? (2)
- With dental problems only
- Fixed appliance – to align arch + intrude incisors + procline lower incisors
- With both skeletal and dental problems
- Orthognathic surgery (for marked class II skeletal pattern or altered vertical skeletal proportions cases)
- Pre-surgical fixed appliance – correct dental problems
- Surgery (VSSO) – advance mandible
- Post-surgical fixed appliance – alignment and levelling
- Orthognathic surgery (for marked class II skeletal pattern or altered vertical skeletal proportions cases)
- Need the help of Oral Maxillofacial Surgeon
A 10 years old girl complaining of her front teeth “sticking out”. (Class II div 1)
E/O photographs: incompetent lips, average MPA & facial proportion, slightly acute nasio labial angle Intra-oral photographs: Class II incisor and molar relationship, increased overjet
Cephalometric analysis: everything normal except SNA and “A, B on OP” increased
Study cast: no apparent spacing or crowding in both arches
k. To retract the upper incisors, which one, bodily movement or tipping movement, would be more suitable? Briefly describe how you can achieve such movement. (2)
Bodily by fixed appliance
Apply force close to its centre of resistance, use of rectangular wire
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
a. List out the extra oral orthodontics diagnosis. (5)
- Skeletal pattern
- Anteroposterior
- Class I – the mandible is 2 – 3 mm posterior to maxilla
- Class II – the mandible is retruded relative to the maxilla
- Class III – the mandible is protruded relative to the maxilla
- Anteroposterior
- Vertical
- Lower facial height
- Frankfort mandibular planes angle
- Transverse
- Extent of asymmetry and whether only the lower facial third or the maxilla or orbits are involved should be recorded.
- Soft Tissues
- Lips
- The form, tonicity, and fullness of the lips.
- Lip competence
- Lower lip position relative to the upper incisors
- The smile aesthetics
- Tongue
- Lips
- Temporomandibular joints
- Habits
- Lip-sucking habits
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
b. List out the intra oral orthodontics diagnosis. (5)
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
c. 3 questions
i. Is there any genetic factor causing the malocclusion of the patient? What is it? (1)
- Supernumerary teeth or small arch
- More number teeth will need to fit in a small arch
- Space required more than space available
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
c. 3 questions
ii. Is there any environmental factor causing the malocclusion of the patient? What is it? (1)
- Sucking habits and mouth breathing
- Sucking habits will lead to an overbite
- Mouth breathing will lead to oral musculature imbalance hence the teeth will be more protruded
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
c. 3 questions
iii. What is a common quantitative assessment of malocclusion? What are the two elements included in this assessment? (3)
Index of orthodontics treatment needed, include dental health and aesthetics components
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
d. 3 questions
i. Which line is the one that stands for the relationship between the growth of the cranial base and the maxilla? Name it. (2)
B (Maxillary plane)
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
d. 3 questions
ii. Which line is the one that stands for the relationship between the growth of the cranial base and the mandible? Name it.
C (Mandibular plane)
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
d. 3 questions
iii. What is line E? (1)
Rickett’s E plane (from soft tissue chin and tip of nose)
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
e. Five methods to relieve crowding.
i. What are the methods to relieve crowding by increasing the arch length? (3)
Arch expansion
Distalization of molars
Proclination of incisors
- Orthodontics (photos and study casts are provided) On a Cephalometric tracing diagram, 5
lines are marked. (Formative 2009)
e. Five methods to relieve crowding.
ii. What are the methods to relieve crowding by decreasing the need of teeth length? (2)
Interproximal enamel stripping
Extraction
A 13 years old patient, her mother with similar malocclusion. Habit: biting of lower lips Increased overjet Cephalometric analysis: LI/MnPI lower than normal but within normal value
g. In the same case but for a 30 years old patient, what is your treatment plan for the patient? What disciplines would be involved in this treatment option? (2)
A 10 years 4 month girl patient, no family history of the similar malocclusion. C/O: irregular teeth
MH: allergic to an antibiotic
E/O, I/O: Anterior cross bite of 21, edge to edge incisal condition
Lateral cephalomatric all values within normal range except Me-MxPl PA shows an odontome mesial to unerupted 13 with 53 in place
f. List 4 problems the abnormality can cause?
Given: 12 year old patient has anterior open bite, with tongue thrusting History: no familial history of anterior open bite
d. Give the formula of facial proportion.
