School of Dentistry
ORTHODONTICS LECTURE 14
SELECTION OF ORTHODONTIC CASES
Sources of difficulty
Patient factors
-
Orthodontic considerations - -
Co-operation, attendance, oral hygiene
Skeletal factors
Soft tissue factors
Tooth malpositions
-
Four important relationships
Four types of swallow
Planning Treatment
Decide on objectives
Plan final tooth positions (Use models if necessary – Kesling set-up)
Assess space requirements - MDA, Space analysis – measure displaced contact in each quadrant
List stages of treatment. Define objectives for each stage
GDPs are paid by results on the basis of start and finish models. PAR scoring is beginning to be
introduced by the DPB and in the future it is possible that dentists will be paid for an
“Improved” or “Greatly improved” outcome but not otherwise. It is therefore important that
GDPs select cases carefully and treat only those that will give a results within a reasonable time
using relatively simple appliances. If removable appliances are to be used a maximum of three
is a good yardstick. The best measure of what to treat is the orthodontic experience of the
individual.
If a GDP is uncertain as to the best orthodontic treatment plan, the patient should be referred for
advice to a Consultant Orthodontist. The alternative will be to refer to a Specialist Orthodontic
Practitioner but this will result in treatment rather than advice.
Read the development of the PAR Index. Richmond et al., 1992 EJO 14, 125-139.
Before referral the GDP should tell the patient and parents:
The reason for referral
That the first hospital visit is for advice
Treatment may or may not be offered.
That there will be a waiting list for treatment
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Patients who are referred should:
Be regular attenders at the practice of the referring dentist
Have good OH - Plaque score below 10%.
Be aware of the personal commitment needed
Have a malocclusion severe enough to warrant treatment. (IOTN Grades 4.) Patients
must appreciate that referral is for advice in the first instance, treatment may or may not
be offered.
Content of the referral letter:
Outline of problem
Past attendance record
Level of patient/parental concern
Previous orthodontic treatment
Relevant medical and dental history (including caries)
Confirmation that likely treatment has been discussed
Signature of dentist
Patients normally accepted for treatment:
IOTN Grades 4 and 5 (Learn the IOTN system.)
Facial clefts
Adults requiring orthognathic treatment
Interdisciplinary cases
Transfers from other hospitals
Suitable for GDP with undergraduate training only:
Tooth behind bite
Unilateral cross bite
Class II(I)
-
extract upper fours only
Class I
-
extract all fours + space maintainers
Suitable for GDP with further training:
Class I with anterior crowding
Class II(I)
Class II(I)
-
extract all fours
headgear for molar correction
lower lingual arch/fixed appliance
buccal segment retraction with or without second molar extraction
Specialist only:
Severe skeletal anomaly:
O/J > 6mm or < Edge to edge
Traumatic overbite or Symmetrical anterior open bite
Cases with mild or severe crowding
Atypical extraction cases
Missing teeth
Surgery
Adults
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All
IMPORTANT GENERAL RULES
IF REFERRAL IS CONTEMPLATED DO NOT:
Extract teeth - primary or permanent
Fit an appliance
Refer early to beat the waiting list
NEVER:
Extract lower premolars in a Class II division 2
Extract upper premolars in a Class III before crossbite correction
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THE DENTAL HEALTH COMPONENT OF THE INDEXOF ORTHODONTIC
TREATMENT NEED (IOTN)
Grade 5 (very great)
5a
Increased overjet greater than 9mm.
5h
Extensive hypondontia with restorative implications (more than 1 tooth missing in any
quadrant) requiring prerestorative orthodontics.
5i
Impeded eruption of teeth (with the exception of third molars) due to crowding,
displacement, the presence of supernumerary teeth, retained deciduous teeth and any
pathological cause.
5m
Reverse overjet greater than 3.5mm with reported masticatory and speech difficulties.
5p
Defects of cleft lip and palate.
5s
Submerged deciduous teeth.
Grade 4 (great)
4a
Increased overjet greater than 6mm, but less than or equal to 9mm.
4b
Reverse overjet greater than 3.5mm with no maticatory or speech difficulties.
4c
Anterior or posterior cross-bites with greater than 2mm discrepancy between retruded
contact position and intercuspal position.
4d
Severe displacements of teeth greater than 4mm.
4e
Extreme lateral or anterior open bites greater than 4mm.
4f
Increased and complete overbite with gingival or palatal trauma.
4h
Less extensive hypodontia requiring prerestorative orthodontics or orthodontic space
closure to obviate the need for a prosthesis.
4l
Posterior lingual cross-bite with not functional occlusal contact in one or both buccal
segments.
4m
Reverse overjet greater than 1mm, but less than 3.5mm with recorded masticatory and
speech difficulties.
4t
Partially erupted teeth, tipped and impacted against adjacent teeth.
Grade 3 (moderate)
3a
Increased overjet greater than 3.5mm, but less than or equal to 6mm with incompetent
lips.
3b
Reverse overjet greater than 1mm, but less than or equal to 3.5mm.
3c
Anterior or posterior cross-bites with greater than 1mm but less than or equal to 2mm
discrepancy between retruded contact position and intercuspal position.
3d
Displacement of teeth greater than 2mm, but less than or equal to 4mm.
3e
Lateral or anterior open bite greater than 2mm, but less than or equal to 4mm.
3f
Increased and complete overbite without gingival or palatal trauma.
Grade 2 (little)
2a
Increased overjet greater than 3.5mm, but less than or equal to 6mm with competent lips.
2b
Reverse overjet greater than 0mm, but less than or equal to 1mm.
2c
Anterior or posterior cross-bite with less than or equal to 1mm discrepancy between
retruded contact position and intercuspal position.
2d
Displacement of teeth greater than 1mm, but less than or equal to 2mm.
2e
Anterior or posterior open bite greater than 1mm, but less than or equal to 2mm.
2f
Increased overbite greater than or equal to 3.5mm without gingival contact.
2g
Pre-normal or post-normal occlusion with no other anomalies. Includes up to half a unit
discrepancy.
Grade 1 (none)
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Extremely minor malocclusions including displacements less than 1mm.
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