An assessment of orthodontic treatment using occlusal indices.

This retrospective study was carried out to assess the need for orthodontic treatment and the standard of treatment provided by the Government Dental Clinic in Singapore. The materials for this study comprised the pre-treatment and post-treatment study models as well as the clinical notes of 194 patients who were consecutively debanded over a three-month period in 1996. The pre- and post-treatment models were assessed using the Index of Orthodontic Treatment Need (IOTN) and the Peer Assessment Rating (PAR) index. The results indicated that a large proportion (81.4%) of the cases were treated with extractions. The majority of the cases were treated by upper and lower fixed appliances. Treatment was completed, on average, in 21 visits spread over 2.1 years. The result also demonstrated that the majority of the patients had genuine need for treatment for both dental and aesthetic reasons. Eighty-two percent of patients fell into the category of "need" for treatment based on dental health grounds. The mean PAR score reduction was 77%, indicating a high standard of treatment.     

The long-term benefits of orthodontic treatment

OBJECTIVE :This study aimed to evaluate post-treatment changes at least five years out of retention in a cohort of 100 consecutively started patients treated by a postgraduate student in a UK orthodontic department. DESIGN: Analysis of study models using recognised occlusal indices. Setting Patients initially treated at Newcastle Dental Hospital were recalled for record collection. MATERIALS AND METHODS: Study models and clinical photographs were taken for each patient attending for post-retention records. Weighted Peer Assessment Rating (PAR) Index and Index of Orthodontic Treatment Need (IOTN) scores were recorded for cases at the beginning, end and at least 5 years post-retention. Main outcome measures Post-treatment changes were evaluated using PAR Index and IOTN to evaluate extent and likelihood of change and to compare treatment modalities. RESULTS: Seventy-eight patients attended for post-retention records. Overall PAR reduction immediately post-treatment was 68.6% and at a mean of 6.5 years post-retention was 55.5%. Dual arch fixed appliance treatments achieved the greatest reduction in PAR score, and maintained the reduction beyond the retention period better than other treatment modalities. Eighty-four per cent of the cohort still had some demonstrable improvement after a mean of 6.5 years post-retention. There was a residual need for treatment in 8% of cases on aesthetic grounds and in 24% of cases on dental health grounds. CONCLUSIONS: Occlusal deterioration after orthodontic treatment is almost universal. Dual arch fixed appliance treatment provides the best post-treatment and post-retention result.     

Outcome of a scheme for specialist orthodontic care, a follow-up study in 31-year-olds

Changes in the occlusion after orthodontic treatment have in several studies been analyzed by the use of the PAR Index developed by Shaw & Richmond. The use of the PAR Index has been shown by O'Brien & Shaw to be a reliable and reproducible method to evaluate orthodontic treatment results. The purpose of the study was to examine the long-range orthodontic treatment outcome by following a group of patients into adulthood to the age of 31 years. For the study 115 individuals from a previous randomized study were invited for follow-up examination at age 31 years. Seventy-two individuals, 32 males (44.4%) and 40 females (55.6%) of the original sample attended for clinical examination. Study casts were obtained and questionnaires addressing the patient's awareness and opinion of the treatment were distributed. In addition twenty-four subjects responded by returning filled-in questionnaires. The mean change in wPAR scores from start to retention represents a mean relative improvement in occlusion of 78.7%. The mean wPar score improvement from age 19 to 31 years was 11.9%. The relative mean wPar score change dropped to 53.5% at age 31 years. The differences in wPAR recordings between the recorded stages were all statistically significant. The treatment outcome as expressed by mean wPAR scores at age 31 years was significantly better among individuals treated with extractions compared to those treated without extractions. The mean wPAR scores of the individuals with retainers at age 31 years were significantly lower when compared to the mean score for those without retainers (unpaired t-test, p = 0.020). This clearly indicates the benefit of long-term retention. The changes in the concern scores from 19 to 31 years of age were small. At age 31 years only 8 of the 96 respondents (8.3%) expressed concern about the treatment outcome.     

Finishing occlusion, degree of stability and the PAR index

The occlusions of sixty-five patients, treated by one private specialist orthodontist with consistent philosophy and goals, were assessed according to the PAR Index. For each patient, pre-treatment, post-treatment and follow-up study models were assessed. Follow-up models were taken at least 6.5 years following the removal of all retention appliances. Mean-weighted PAR scores were calculated for the total sample and various sub-groups at each stage. Mean percentage changes in weighted PAR scores were also calculated. The relationships between the occlusal standards at the end of active treatment and at the end of the follow-up period, and specific diagnostic and treatment factors were then investigated to search for any factors that might be predictive of long-term post-treatment occlusal stability or instability. The overall mean-weighted pre-treatment, post-treatment and follow-up PAR scores were 25.5, 3.0 and 7.0, respectively. There was an 85.6 per cent decrease with treatment in the overall mean-weighted PAR score. This was followed by a 15.2 per cent increase in that overall mean during the follow-up period. In this introductory study, neither the PAR score at the end of active treatment, nor the amounts of occlusal change occurring during or after active treatment, were found to be predictive of the amount of post-treatment occlusal change.     

Evaluation of orthodontic treatment, retention and relapse in a 5-year follow-up: a comparison of treatment outcome between a specialist and a post-graduate clinic

The aim of this study was to evaluate and compare orthodontic treatment between a specialist clinic and a post-graduate clinic. A long-term follow-up study was done 5 years after orthodontic treatment ended. Eighty-one individuals treated at the Post-graduate clinic at the Department of Orthodontics, University Clinics of Odontology, G?teborg, and 84 individuals treated at the Orthodontic Specialist Clinic in V?nersborg, the county of V?stra G?taland were examined. The Peer Assessment Rating (PAR) index was used on pre-, post-treatment and 5-year follow-up study casts. The percentage reduction in weighted PAR (WPAR) scores after treatment and at the 5-year follow up did not differ significantly between the clinics. There were significant higher pre-, post-treatment and 5-year follow-up PAR and WPAR scores in patients from the Specialist Clinic as compared with patients from the Post-graduate Clinic. In the whole sample 97.6% of the patients were improved or greatly improved after treatment and 95.8% were still improved or greatly improved 5 years after treatment. Sixty-seven percent of the patients still had retainers in one or both arches at the 5-year follow-up. The WPAR scores are one factor that indicates the high quality of the treatment process in both clinics. The higher post-treatment PAR scores in the Specialist Clinic may be because a larger number of patients were treated only in one jaw at this clinic.     

Adult patients' view of orthodontic treatment outcome compared to professional assessments

One important aspect in evaluating the outcome and quality of orthodontic treatment is the patient's own assessment. The objective of this study was to evaluate the course and outcome of orthodontic treatment in adults from the patient's vs the operator's point of view. In a previous study, the orthodontic treatment of 88 adults was evaluated using the IOTN and PAR Index before and after treatment. Fifty-nine patients answered treatment questionnaires on 1. the reason for seeking treatment, 2. dentofacial aesthetics, 3. treatment outcome, 4. course of treatment, 5. attitude, 6. social well-being. Depending on the original treatment goal, the patient population was divided into an Ideal Group and a Compromise Group. In 75% of the patients, dissatisfaction with dental aesthetics was the prime motive for seeking treatment; correlations with PAR parameters (overjet and maxillary anterior teeth) were weak. In general, a high degree of patient satisfaction with orthodontic treatment was registered. As regards satisfaction with post-treatment dental aesthetics there were no significant differences between the groups. Comparison of professional assessment with the subjective rating by patients revealed discrepancies in that the patients' rating of outcome tended to be more positive. The differentiation between ideal and compromise treatment goals proved useful. In the Compromise Group, a high level of patient satisfaction was attained with a shorter treatment duration and lower appliance involvement. 92% considered their major pre-treatment need to have been met, and 95% would have had the treatment performed again.     

Comparison of orthodontic treatment outcomes in educational and private practice settings

An accredited graduate orthodontic program provides advanced specialty education to meet standards of care mandated by the ADA, including both didactic and clinical components with defined outcome measures. To quantify these measures, the quality of care provided by graduate orthodontic students was compared to that of orthodontists in private practice. The quality of care was studied in two different delivery settings in the Columbus, Ohio, area-private practice orthodontists (PPO) and the OSU graduate orthodontic clinic (GOC). The Peer Assessment Rating (PAR) Occlusal Index was used as a measure of malocclusion severity and post-treatment occlusal outcome. Quality of care was measured using post-treatment PAR, percent PAR reduction, and treatment duration. At baseline, no differences were seen in the gender and pre-PAR scores of patients treated by the PPO and GOC, but statistically significant differences were seen in patients' pre-treatment age, race, and starting dentition. When the post-treatment occlusal results were compared, no statistically significant differences were seen in post-PAR scores and percent PAR reduction between the PPO and GOC. A statistically significant difference was seen in treatment duration (p = 0.002), which was longer in the PPO even after controlling for confounding factors such as pre-treatment age, gender, race, starting dentition, and treatment stages. Our conclusion is that there was no statistically significant difference in the occlusal outcome between the PPO and GOC, but there was a significant difference in the treatment duration.     

The provision and outcome of orthodontic services in a Norwegian community: a longitudinal cohort study

In a systematic child dental care system, professionals, consumers, and purchasers have a common interest in ensuring that provision and outcome of orthodontic care fulfill the goals of the service and the public's expectations. The purpose of this prospective study was to examine whether treatment was in fact provided to children with a normative treatment need, and also to assess the outcome of treatment. The baseline data were established for a sample of 83 11-year-olds before decisions about orthodontic treatment had been made, by recording the individuals' orthodontic concern as reported in questionnaires and their occlusal condition according to an index of orthodontic treatment need (NOTI). At re-examination at the age of 16 years, it was also recorded whether the individual had received orthodontic treatment. Most individuals (83%) with a normative need had been treated as well as some individuals without need but who had expressed orthodontic concern. Treatment had resulted in occlusal improvement ('health gain') in most patients, and generally this improvement paralleled a decrease in concern. The goals of the orthodontic service seem to have been fulfilled to the extent that residual treatment need was infrequent. The high treatment rate (63%) and standard may explain why all individuals, both treated and untreated, expressed satisfaction with their dental appearance at 16 years of age.     

Treatment and standard evaluation using the Peer Assessment Rating index

The aim of this retrospective study was to determine the outcome of orthodontic treatment carried out on patients by postgraduate students at the Katholieke Universiteit Leuven, Belgium. The treatment outcome of 292 'final examination' patients and of 287 'control' patients was compared by means of the Peer Assessment Rating (PAR) index. The sample consisted of dental casts representing a wide range of malocclusions at the start of treatment and post-treatment. All patients received non-surgical treatment between 1987 and 1996 by one of 18 different postgraduate students. The data were analysed with a variant of the analysis of covariance. A significantly higher (P < 0.001) treatment standard was found for final examination patients compared to the control, indicated by the mean percentage PAR score reduction of 79.1% and 70.7%, respectively. When the results are expressed in terms of treatment outcome, 44.5% of the examination patients and 44.0% of the controls were allocated to the 'Greatly improved' group, while 3.1% of the patients examined and 7.3% of the control patients were classified as 'Worse or no different'.     

The seven-year outcome of an early orthodontic treatment strategy

The benefits of early orthodontic treatment are continuously discussed, but studies are few. We examined whether definite need for orthodontic treatment could be eliminated in public health care by systematically focusing on early intervention. One age cohort living in a rural Finnish municipality (N = 85) was regularly followed from ages 8 to 15 years, and persons with malocclusions were treated according to a pre-planned protocol. Treatment need was assessed according to the Dental Health Component (DHC) of the Index of Orthodontic Treatment Need, and treatment outcome by the Peer Assessment Rating Index (PAR). Fifty-two percent of the cohort received treatment, and definite treatment need decreased from 33% to 9%. In the treated group, the mean PAR score reduction was 63%, and 51% showed more than 70% improvement. The results suggest that an early treatment strategy may considerably reduce the need for orthodontic treatment in public health care with limited specialist resources.     

Effectiveness of phase I orthodontic treatment in an undergraduate teaching clinic

In this retrospective study, the Peer Assessment Rating (PAR) index was used to objectively evaluate the effectiveness of Phase I (early) orthodontic treatment provided in an undergraduate teaching clinic. Pre-treatment and post-treatment casts of ninety-three patients were analyzed. All patients selected for Phase I orthodontic treatment had Class I skeletal relationships and did not require complex orthodontic treatment such as growth modification or treatment of occlusions with missing or impacted teeth. The mean age of patients who received Phase I orthodontic treatment was 9.9 years. The mean initial PAR score for the sample was 29.70 +/-9.84. The mean reduction in PAR score was 14.9 points corresponding to a 50.2 percent decrease in the PAR score following Phase I orthodontic treatment. Seventy-three percent of the patients experienced at least a 30 percent reduction in their PAR score following Phase I (early) orthodontic treatment. The mean cost of $381.00 for the Phase I orthodontic treatment was found to be influenced by the length of treatment, type of Phase I treatment provided, age at start of treatment, and percentage reduction in PAR score. The greatest success rate for the Phase I orthodontic treatment occurred with either fixed or a combination of fixed and removable appliances. Over half of the patients recommended for Phase I orthodontic treatment in the undergraduate dental clinic were successfully treated and did not require Phase II treatment. For them, there was both a treatment and a financial benefit to the Phase I orthodontic treatment.     

Patient-centered evaluation of orthodontic care: a longitudinal cohort study of children's and parents' attitudes.

As health services are adapted to meet consumers' needs, patient-centered evaluation of quality of care as well as informed consent to treatment decisions become increasingly important concepts in orthodontics. In an attempt to assess the orthodontic service in a region, this study focused on attitudes among children and their parents. The attitudes were recorded both before and after the period in which orthodontic treatment is usually carried out. Changes in children's and parents' attitudes were applied to measure outcome of care, and to evaluate the relevance of informed consent in decisions about treatment. Seventy-nine family units were interviewed with the use of questionnaires when the child was 11 years of age and again at 16 years. Both orthodontically treated and untreated subjects were included. Responses to questions about satisfaction with dental appearance and desire for treatment were transformed to a score for orthodontic concern. A significant decrease in the concern score was observed over the 5-year period among the treated subjects, and the care system apparently identified and provided treatment to the majority of those children concerned at 11 years. Intra-unit disagreement in concern was observed among 25% of the child/parent units at the 11-year stage, whereas at 16 years nearly all units agreed. Informed consent as a tool to ensure patients' autonomy when decisions about treatment are made did not appear to be negatively affected by conflicting attitudes between children and their parents.     

Outcome of combined orthodontic-surgical treatment in a United Kingdom university dental institute

Introduction: This retrospective observational cohort study evaluated effectiveness of combined orthodontic–orthognathic surgical treatment in a UK University Dental Institute. Methods: Patients were identified from a database maintained prospectively throughout a 5-year period of observation. Demographic and clinical data included age, malocclusion, Index of Treatment Need, Index of Orthognathic Functional Treatment Need, orthodontist, surgeon, surgical procedure and treatment-time. Peer Assessment Rating (PAR) scores were generated from pre- and post-treatment dental study casts by a single calibrated examiner. Results: One hundred and sixty two subjects began treatment during the period of observation, 92 completed, 14 elected to discontinue before surgery and 56 remained in treatment. Outcome data were available for 73, 16 males and 57 females (mean age 23.28 [SD, 7.92] years). Within this sample, 33 (45.2%) presented with class II division 1, 6 (8.2%) with class II division 2 and 34 (46.6%) with class III malocclusion. Isolated maxillary and mandibular surgery was carried out in 3 (4.1%) and 24 cases (32.8%), respectively; bimaxillary surgery was performed in 46 (63.1%). Mean total treatment time in fixed appliances was 920.28 days (30.7 months). Mean pre-treatment PAR score was 39.09 [SD, 9.42] and post-treatment 5.86 [SD, 4.25] with a mean 83.7% PAR score reduction, representing a greatly improved occlusal result. Kruskal–Wallis testing found no evidence of any relationship between independent variables and percentage PAR reduction; however, surgeon identity did significantly influence treatment length (P?=?0.007). Conclusions: This investigation demonstrates that in terms of static occlusion combined orthodontic–orthognathic surgery is effective in correcting severe malocclusion.     

应用PAR指数对332例错畸形矫治结果的评估

目的评估和分析影响矫治结果的相关因素。方法采用ＰＡＲ指数对３３２例使用固定矫 治器治疗的治疗前后模型进行评估分析。结果（１）最终的矫治结果与性别无关，但女性较男性在精细 调整方面要求更高。（２）年轻的患者相对年长者较易取得更完善的矫治效果。（３）方丝弓矫治器和Ｂｅｇｇ 矫治器同样有效，但各有优缺点。（４）矫治结果的改善程度与错程度有关，错程度轻、非拔牙者，矫治 结果的改善程度较低。（５）不对称拔牙是造成中线偏斜的主要原因。结论制定合理的矫治方案，选用 合适的矫治方法和适当的矫治时机，是取得高水平矫治结果的关键。     

Orthodontic treatment outcome in a First Nations population in Alberta, Canada: a comparative study.

The primary objective of this study was to determine whether there was a significant difference in the degree of improvement after orthodontic treatment between a sample of First Nations orthodontic patients and a control sample of non-First Nations orthodontic patients. The secondary objective was to determine whether there was a difference in the severity of malocclusions being treated in a sample of the First Nations patients compared with a control sample of the non-First Nations patients. Several factors that might affect treatment outcome, such as missed appointments, treatment duration, oral hygiene, extractions, dental classification, and geographic location, were also studied. A sample of 60 First Nations patients and a control group of 60 non-First Nations patients between the 11 and 18 years of age who had been treated with full fixed orthodontic appliances were evaluated. The weighted peer assessment rating (PAR) index was applied to pretreatment and posttreatment study models to address the study's main objectives. The results showed that the First Nations group had greater PAR scores pretreatment than did the controls, and their weighted PAR scores improved more with treatment. Posttreatment PAR scores were similar between the 2 groups. In addition to First Nations status, only extractions and geographic location affected PAR improvement scores.     

直丝弓与方丝弓矫治器的疗效比较

目的 应用PAR指数评价直丝弓矫治器与方丝弓矫治器的治疗效果。方法 选取北京大学口腔医院正畸科1994-2001年采用直丝弓或方丝弓双颌固定矫治器完成治疗的错畸形患者80例,对治疗前后模型进行PAR指数测量,记录治疗前后PAR分值及其差值,以治疗前相同的PAR总分值和拔牙、非拔牙矫治方式将患者进行配对分组,分为直丝弓组和方丝弓组,每组40例,对两组患者的测量数据进行统计学检验。结果 治疗后直丝弓组后牙排列的PAR分值低于方丝弓组（P＜0.01）,后牙排列效果较方丝弓组好。两组患者治疗后其余各项PAR分值及治疗前后PAR差值均无统计学差异（P＞0.05）。直丝弓组平均疗程缩短3.95个月。结论 直丝弓矫治器对牙齿排列尤其是后牙的定位较准确,在较短的时间内可取得与方丝弓矫治器相同的治疗效果,矫治效率较方丝弓矫治器高。     

安格尔Ⅱ类1分类错耠畸形临界病例拔牙与否的正畸治疗效果评估

目的通过对安格尔Ⅱ类1分类错胎临界病例正畸前后的牙胎模型同行评估等级（PAR）指数分析,评估这类患儿拔牙与否的正畸治疗效果,为临床医师制定矫治计划提供参考。方法选择83例平均年龄（12．6±1．1）岁的安格尔Ⅱ类1分类错胎临界病例为研究对象,其中拔牙57例,非拔牙26例,应用PAR指数对其治疗前后的牙胎模型进行评分,比较拔牙组与非拔牙组矫治前后错胎的分值变化,进而评估两组正畸治疗的效果。结果安格尔Ⅱ类1分类错验临界病例不论拔牙与否,治疗后的加权PAR指数总分均较治疗前明显减小,加权PAR指数减少率均大于70％,且两组之间的加权PAR指数总分差异无统计学意义;治疗效果明显改善者为96．39％（80／83）。结论安格尔Ⅱ类1分类错胎临界病例拔牙与否,均可在牙胎关系方面收到较好的治疗效果。     

Effectiveness and duration of two-arch fixed appliance treatment

The aims of this study were to determine the effectiveness and duration of single-phase two-arch fixed appliance treatment and to evaluate factors that may influence these two variables. Data were collected from 177 consecutively completed cases at the Orthodontic Department, Government Dental Clinic, Singapore, during a three-month period. Pre-treatment and post-treatment models were assessed using the Peer Assessment Rating (PAR) index. The result showed that two-arch fixed appliance treatment reduced the malocclusions on average by 77.80 per cent over a period of 25 months. Multiple regression techniques revealed that 22 per cent of the variability in treatment effectiveness could be explained by the pre-treatment PAR score, the age at the start of treatment, the frequency of office visits and whether or not the treatment involved extractions. The variation in treatment duration was due to the frequency of office visits, the pre-treatment PAR score and whether or not the treatment involved extractions or headgear.     

Peer Assessment Rating (PAR) index outcomes for orthodontic and orthognathic surgery patients

The Peer Assessment Rating (PAR) index is commonly used to evaluate occlusal outcomes after orthodontic treatment. We compared the PAR outcomes of 40 consecutively treated orthodontic patients and 40 orthognathic patients to evaluate the standard of care given. A patient-centred questionnaire was used to examine patients’ perceptions of the benefits of orthognathic treatment. PAR scores of orthodontic and orthognathic patients improved by a mean of 77% and 74%, respectively, after treatment indicating that excellent to good occlusal results were achieved for both groups. A high quality occlusal outcome is important for all patients as good intercuspation at the end of treatment is thought to improve stability. Most orthognathic patients reported improvements in their dental and facial appearance and thought that the treatment had been beneficial.     

An approach to maintain orthodontic alignment of lower incisors without the use of retainers

The purpose of this investigation was to examine the long-term stability of orthodontic alignment of lower incisors without the use of retainers. The study sample comprised 56 patients treated according to a protocol that included over-correction of rotated teeth at an early stage of treatment and systematic enamel reduction (stripping) of the approximal surfaces in the mandibular anterior region, both during treatment and follow-up. Care was also taken to maintain dental arch form and to avoid lateral expansion of the lower dental arch and proclination of the incisors. Dental study casts were obtained pre-treatment, at the end of treatment, and 3 years post-treatment. Alignment of the mandibular incisors was recorded using Little's irregularity index. The inter-canine distance and the sum of the mesio-distal widths of the mandibular incisors and canines were also measured.The total amount of enamel removed from the approximal surfaces of the lower anterior teeth ranged from 0.3 to 5.0 mm (mean 1.9 mm). The mean increase in irregularity index score of 0.6 from post-treatment to 3 years follow-up indicated good stability. In 45 per cent of the patients the change in score during this period was less than 0.5, indicating that the treatment approach presented may be considered an alternative strategy to placement of lower retainers to safeguard the stability of alignment of mandibular incisors.