Peer Assessment Rating (PAR) index outcomes for orthodontic and orthognathic surgery patients
Introduction
Clinicians have a duty to ensure that systems are in place to produce acceptable treatment outcomes. Clinical outcomes after orthodontic treatment are often measured using occlusal indices to establish the overall standard of care. Occlusal indices are measured from study models taken before and after completion of treatment.
The Peer Assessment Rating (PAR) index is commonly used and has validity and reproducibility.1, 2, 3 It is a useful tool that can be used to audit the outcomes of orthodontic treatment objectively, and has been used extensively in Europe.4, 5, 6, 7, 8 It is a suitable index for the assessment of outcome and improvement in patients treated with a combined orthodontic and orthognathic approach.9
PAR scores are measured from plaster study models taken before and after treatment to establish a mean reduction in the score; a mean improvement of more than 70% represents a very high standard of treatment. Ideally the number of patients in the “worse, or no improvement” category should be less than 5%.1
Patient-centred questionnaires can also be used to assess the patient's experience of treatment. Travess et al.10 developed a validated questionnaire to examine patients’ perceptions of the process, and the outcome of combined orthodontic and orthognathic treatment. This questionnaire was used in 13 hospitals in the south west region of the UK.11, 12
The primary aim of this prospective service evaluation was to assess occlusal outcomes using the PAR index in 40 consecutively treated orthodontic and 40 orthognathic patients. The secondary aim was to assess the patients’ perceptions of the benefits of orthognathic treatment.
Section snippets
Methods
Forty consecutive patients who had had orthodontic treatment to correct their malocclusion, and 40 consecutively treated patients with dentofacial deformities who had had a combination of orthodontic and surgical treatment were identified within our local maxillofacial unit. Selection commenced in January 2007. All patients in the orthognathic group had rigid internal fixation. Orthodontic treatment was carried out by five clinicians within the department, and the operations by one of three
Results
All 40 sets of study models (before and after treatment) were available for the orthodontic group, and they were PAR scored. One set of models from the orthognathic group (before treatment) was not available, so only 39 full sets were PAR scored.
A sample of 40 sets of study models (20 orthodontic, 20 orthognathic) were re-examined and reproducibility was calculated with the kappa statistic. Reliability within and between examiners was 0.84 (95% CI, 0.70–0.97), which indicated good reliability.
Discussion
The mean percentage improvement in PAR scores for orthodontic and orthognathic treatment were 77% and 74%, respectively, which indicates excellent to good occlusal results for both groups. The better improvement in the orthodontic group does not agree with Richmond et al.1 who reported a higher reduction in orthognathic surgical cases than in orthodontic cases. Although the overall mean percentage reduction in the PAR scores was similar for both groups, the mean scores before treatment were
Acknowledgements
We thank John Endean, laboratory technician, and Mr. Stephen Robinson, consultant orthodontist for their input into this study.
References (18)
- et al.
The validation of the Peer Assessment Rating for malocclusion severity and treatment difficulty
Am J Orthod Dentofacial Orthop
(1995) - et al.
Evaluation of the Peer Assessment Rating (PAR) index as an index of orthodontic treatment need
Am J Orthod Dentofacial Orthop
(2002) - et al.
Prospective, multi-center study of the effectiveness of orthodontic/orthognathic surgery care in the United Kingdom
Am J Orthod Dentofacial Orthop
(2009) - et al.
Patients’ experiences after undergoing orthognthic surgery at NHS hospitals in the south west of England
Br J Oral Maxillofac Surg
(2004) - et al.
Orthodontic preparation for orthognathic surgery: how long does it take and why? A retrospective study
Br J Oral Maxillofac Surg
(2003) - et al.
Perceptions of outcome following orthognathic surgery
Br J Oral Maxillofac Surg
(1996) - et al.
The development of the PAR index (Peer Assessment Rating): reliability and validity
Eur J Orthod
(1992) - et al.
The use of occlusal indices in assessing the provision of orthodontic treatment by the hospital orthodontic service of England and Wales
Br J Orthod
(1993) - et al.
Orthodontic treatment standards in Norway
Eur J Orthod
(1993)
Cited by (19)
Did the coronavirus disease 2019 pandemic affect orthodontic treatment outcomes? A clinical evaluation using the objective grading system and Peer Assessment Rating index
2022, American Journal of Orthodontics and Dentofacial OrthopedicsCitation Excerpt :This study found no differences in treatment duration between the groups, measured from the time appliances were placed to the time removed (Table I). Factors that may influence the treatment duration include age, gender, the severity of malocclusion, extractions, and clinician experience.36 This study shows that PAR reduction or total OGS score were not associated with treatment duration even though group 2 had significantly fewer and irregular appointments and a significantly less total number of appointments, raising the question of whether some control intervals can be partly replaced by teleorthodontics (Table I).
Variation in UK Deanery publication rates in the British Journal of Oral and Maxillofacial Surgery: where are the current 'hot spots'?
2021, British Journal of Oral and Maxillofacial SurgeryEffectiveness of lingual versus labial fixed appliances in adults according to the Peer Assessment Rating index
2019, American Journal of Orthodontics and Dentofacial OrthopedicsCitation Excerpt :The results of the present study are consistent with those published by Luther et al.25 Another study26 concluded that age differences do not seem to play a role in the duration of the treatment, provided that patients are in the permanent dentition. As indicated by Ponduri et al,4 Dyken et al.9 reported that a high PAR score before treatment and a large percentage reduction in the score were significantly associated with long durations of treatment. However, the occlusal index scores after treatment were not associated with duration.
Patient expectations and satisfaction following orthognathic surgery
2019, International Journal of Oral and Maxillofacial SurgeryCitation Excerpt :Ponduri et al. assessed whether treatment would improve the occlusal relationship in 40 patients who had orthodontic procedures and 40 patients who had orthognathic procedures. They found that all participants reported improvements in aesthetics or function, or both12. This is in keeping with the present study results, with 90.7% reporting improved aesthetics following treatment.
Assessing the outcome of orthognathic surgery by three-dimensional soft tissue analysis
2018, International Journal of Oral and Maxillofacial SurgeryReview of orthognathic surgery and related paper spublished in the British Journal of Oral and Maxillofacial Surgery 2011-2012
2015, British Journal of Oral and Maxillofacial SurgeryCitation Excerpt :Ponduri et al. used the Peer Assessment Rating (PAR) index to assess the effect of treatment to improve the occlusal relation in 40 patients who had orthodontic, and 40 who had orthognathic procedures. Outcome was reported as “excellent to good” in both groups, and all participants reported improvement in aesthetics or function, or both.16 In a study of 27 patients undergoing bimaxillary osteotomy, Edler et al. showed that standardised clinical photography and specialised graphics software can be used as a valid quantitative outcome tool to compare interalar width before and after operation, and to assess mandibular asymmetry.17