Peer Assessment Rating (PAR) - Orthodontic Index

Peer Assessment Rating (PAR) - Orthodontic Index

1. Nasir Al-Hamlan BDS, MPH, MSc, FDS RCSEd, FDS RCSEd, MOrth RCSEd, FICD
Consultant and Assistant Professor, Orthodontics
King Saud bin Abdulaziz University for Health Sciences
Riyadh, Saudi Arabia
@nhalhamlan
@saudibraces
nasiralhamlan
@nasiralhamlan
Peer Assessment Rating (PAR)
(Richmond et.al., 1992)

2. Peer Assessment Rating (PAR) (Richmond et.al., 1992)

3. Peer Assessment Rating (PAR) (Richmond et.al., 1992)
• Over 6 meetings with 10 experienced orthodontists to formulate
PAR index by using over 200 SM (pre-/post-treatment),
• Zero = good alignment and higher scores (rarely above 50)
indicate increasing degrees of irregularity,
• Grade treatment results for self teaching device, however; it can be
insensitive and misjudge individual patient needs, therefore it is
not an index of treatment need.

4. COMPONENTS AND WEIGHTINGS
COMPONENTS WEIGHTINGS
Upper/lower anterior segment x 1
Left/right buccal occlusion x 1
Overjet x 6
Overbite x 2
Centerline x 4
• Greatly improve: > 22 points
• Improved: > 30%
• Worse/no different: < 30%

5. Ruler

6. Advantages
• Accumulative scores,
• Gives grading treatment results,
• Reliable (Richmond et al., 1992),
• 2 minutes stated as time required for scoring.

7. Limitation (Hamdan and Rock, 1999)
• Sensitive with increased OJ
• OB low weighting
• Zero weighting for displacement

8. DESCRIPTION

9. • Anterior segments
- ULS/LLS
- Recording zone = canine (mesial contact points)
- Recorded features: Crowding, Spacing, Impaction
- Contact point displacement:

SCORE DISPLACEMENT
0 0 mm – 1 mm
1 1.1 mm – 2 mm
2 2.1 mm – 4 mm
3 4.1 mm – 8 mm
4 > 8 mm
5 Impacted teeth

10. • Anterior segments
-Impactions of canines and incisors are recorded
-Impacted = space between two adjacent teeth is ≤ 4 mm
-Ectopic incisors and canines are recorded in the anterior segment
-Contact point displacement scores and impacted/ectopic teeth
scores are summed ! overall score for anterior segment

11. • Buccal occlusion
-Record left and right and in all three planes
-Recording zone = canine "! LAST molar (either 1st, 2nd or 3
rd)
-All features recorded with teeth in occlusion
-A-P, VERTICAL and TRANSVERSE scores are summed for each buccal segment

12. •Buccal occlusion
Score A-P
0 good interdigitation
1 < ½ unit from full
2 ½ unit (cusp-cusp)

13. •Buccal occlusion
Score VERTICAL
0 no open bite
1 lateral open bite > 2 mm on at least two teeth

14. • Buccal occlusion
Score TRANSVERSE
0 no crossbite
1 crossbite tendency
2 single tooth in crossbite
3 > 1 tooth in crossbite
4 > 1 tooth in scissors bite
• Do NOT sum x-bites and x-bite tendency

15. • Overjet
-Record OJ and anterior crossbites,
-Recording zone most prominent incisal edge,
-Some patients have OJ and anterior x-bite..record both and summate score:
Score OJ Score Anterior crossbite
0 0-3 mm 0 No crossbite
1 3.1 – 5 mm 1 One or more teeth edge-edge
2 5.1 – 7 mm 2 One single tooth in x-bite
3 7.1 – 9 mm 3 Two teeth in x-bite
4 > 9 mm 4 > Two teeth in x-bite
NOTE: Canine crossbites recorded in OJ assessment

16. • Overbite
-Record worst vertical overlap OR openbite of ANY of the four incisors (DO
NOT summate)
OPEN BITE OVERBITE
Score Score
0 No open bite 0 ≤ 1/3
rd Lower Incisor
1 ≤ 1 mm 1 > 1/3rd < 2/3rd Lower Incisor
2 1.1 mm – 2 mm 2 > 2/3
rd Lower Incisor
3 2.1 mm – 3 mm 3 ≥ full tooth coverage
4 ≥ 4 mm

17. • Centerline
- Difference between upper and lower midlines recorded in RELATION TO
LOWER DENTAL MIDLINE and NOT face.
Score Centerline
0 Coincident and up to ¼ lower incisor width
1 ¼ - ½ lower incisor width
2 > ½ lower incisor width

18. PAR- case analysis
• PRETREATMENT
ULS: (3-2) 1, (2-1) 0, (1-1) 0, (1-2) 1, (2-3) 2
Total = 4
Weighting 4 x 1 = 4
LLS: (3-2) 1, (2-1) 0, (1-1) 0, (1-2) 0, (2-3) 0
Total = 1
Weighting 1 x 1 = 1

19. • PRETREATMENT
• RBO: A-P = 0, Vertical = 0, Transverse = 0
Total = 0
Weighting 0 x 1 = 0
• LBO: A-P = 1, Vertical = 0, Transverse = 0
Total = 0
Weighting 1 x 1 = 1
PAR- case analysis

20. PRETREATMENT
• OJ: 10mm = 3, Crossbite = 0
Total = 3
Weighting 3 x 6 = 18
PAR- case analysis

21. PRETREATMENT
Either overbite or openbite
Overbite > 2/3rd of Lower Incisor =2
Total = 2
Weighting 2 x 2 = 4
CL: 1/2 Lower Incisor width = 1
Total = 1
Weighting 1 x 4 = 4
Total Pretreatment Score = 32 points
PAR- case analysis

22. POSTTREATMENT
ULS: (3-2) 0, (2-1) 0, (1-1) 0, (1-2) 0, (2-3) 0
Total = 0
Weighting 0 x 1 = 0
LLS: (3-2) 0, (2-1) 0, (1-1) 0, (1-2) 0, (2-3) 0
Total = 0
Weighting 0 x 1 = 0
PAR- case analysis

23. POSTTREATMENT
RBO: A-P = 1, Vertical = 0, Transverse = 0
Total = 1
Weighting 1 x 1 = 1
LBO: A-P = 0, Vertical = 0, Transverse = 0
Total = 0
Weighting 0 x 1 = 0
PAR- case analysis

24. POSTTREATMENT
OJ: 2mm = 0, Crossbite = 0
Total = 0
Weighting 0 x 6 = 0
Either overbite or openbite = 0
Total = 0
Weighting 0 x 2 = 0
CL: Coincident = 0
Total = 0
Weighting 0 x 4 = 0
Total Posttreatment Score = 1 point
PAR- case analysis

25. Measurement the Treatment Outcome
Points:
Pretreatment score (32) – Posttreatment score (1) = 31

> 22 (Greatly Improved)
Percentage:
Pretreatment score reduced was from 32 to 1 in posttreatment;
therefore, the reduction was 31 points.
32-------------------31
100-----------------96.88
96.88 > 30% (Improved)
PAR- case analysis

26. •Thank YOU