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Class II Etiology and Its Effect on Treatment Approach and Outcome

Permanent Link: http://ufdc.ufl.edu/UFE0041786/00001

Material Information

Title: Class II Etiology and Its Effect on Treatment Approach and Outcome
Physical Description: 1 online resource (31 p.)
Language: english
Creator: Mansour, David
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: class
Dentistry -- Dissertations, Academic -- UF
Genre: Dental Sciences thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: CLASS II ETIOLOGY AND ITS EFFECT ON TREATMENT APPROACH AND OUTCOME Managing a patient with class II malocclusion has been an ongoing discussion in orthodontics. The issues are in regards to timing and treatment approach. The Randomized Clinical Trial (RCT) done at the University of Florida (UF) showed there were no significant skeletal differences between patients treated in two phases versus one phase. Some claim that these results do not correlate to the clinical setting. Purpose: The aim of this study is to determine if orthodontists agree within themselves and each other about the etiology, timing and difficulty of treating patients with a class II malocclusion. Methods: This is a retrospective study, with the patient sample derived from the UF class II study mentioned above. The records were sent to 8 orthodontists, who diagnosed the patients. Within the group of patients, duplicate records of 18 patients were dispersed. Results: The orthodontists decided that there was both a skeletal and dental component to the patient?s malocclusion 47.5% of the time. They felt that the mandible would be the arch they would treat 38% of the time. Overall, the raters were consistent within themselves 65% of the time when determining what type of malocclusion the patients possessed, 60% of the time when deciding which arch was at fault when a skeletal imbalance was noted and 81% of the time when determining need for immediate orthodontic treatment. The raters were consistent 33% and 77% of the time in regards to determining case difficulty and phase-2 treatment need, respectively. There was a small but significant correlation between the consistency of the orthodontist?s responses and the PAR score. Conclusions: When analyzing the duplicate sample of 18 patients, the orthodontists felt that there was both a skeletal and dental component to the malocclusion a majority of the time. The mandible was most commonly chosen as the arch that would be treated. It was also found that the higher the PAR score, the more consistent the orthodontists were in there diagnoses of the case, this was a relatively low correlation however. The intra-rater agreement was moderate when determining the etiology of each malocclusion. Due to this insufficient intra-rater agreement, inter-rater agreement was not calculated and it was therefore impossible to accomplish one of the original goals of comparing treatment outcomes between patients after the etiology of the class II malocclusion was determined.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by David Mansour.
Thesis: Thesis (M.S.)--University of Florida, 2010.
Local: Adviser: Dolce, Calogero.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041786:00001

Permanent Link: http://ufdc.ufl.edu/UFE0041786/00001

Material Information

Title: Class II Etiology and Its Effect on Treatment Approach and Outcome
Physical Description: 1 online resource (31 p.)
Language: english
Creator: Mansour, David
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: class
Dentistry -- Dissertations, Academic -- UF
Genre: Dental Sciences thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: CLASS II ETIOLOGY AND ITS EFFECT ON TREATMENT APPROACH AND OUTCOME Managing a patient with class II malocclusion has been an ongoing discussion in orthodontics. The issues are in regards to timing and treatment approach. The Randomized Clinical Trial (RCT) done at the University of Florida (UF) showed there were no significant skeletal differences between patients treated in two phases versus one phase. Some claim that these results do not correlate to the clinical setting. Purpose: The aim of this study is to determine if orthodontists agree within themselves and each other about the etiology, timing and difficulty of treating patients with a class II malocclusion. Methods: This is a retrospective study, with the patient sample derived from the UF class II study mentioned above. The records were sent to 8 orthodontists, who diagnosed the patients. Within the group of patients, duplicate records of 18 patients were dispersed. Results: The orthodontists decided that there was both a skeletal and dental component to the patient?s malocclusion 47.5% of the time. They felt that the mandible would be the arch they would treat 38% of the time. Overall, the raters were consistent within themselves 65% of the time when determining what type of malocclusion the patients possessed, 60% of the time when deciding which arch was at fault when a skeletal imbalance was noted and 81% of the time when determining need for immediate orthodontic treatment. The raters were consistent 33% and 77% of the time in regards to determining case difficulty and phase-2 treatment need, respectively. There was a small but significant correlation between the consistency of the orthodontist?s responses and the PAR score. Conclusions: When analyzing the duplicate sample of 18 patients, the orthodontists felt that there was both a skeletal and dental component to the malocclusion a majority of the time. The mandible was most commonly chosen as the arch that would be treated. It was also found that the higher the PAR score, the more consistent the orthodontists were in there diagnoses of the case, this was a relatively low correlation however. The intra-rater agreement was moderate when determining the etiology of each malocclusion. Due to this insufficient intra-rater agreement, inter-rater agreement was not calculated and it was therefore impossible to accomplish one of the original goals of comparing treatment outcomes between patients after the etiology of the class II malocclusion was determined.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by David Mansour.
Thesis: Thesis (M.S.)--University of Florida, 2010.
Local: Adviser: Dolce, Calogero.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041786:00001


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CLASS II ETIOLOGY AND ITS EFFECT ON TREATMENT APPROACH AND OUTCOME By DAVID O. MANSOUR A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORID A IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2010 1

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2010 David O. Mansour 2

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To Kelly, Mom, Dad and John for always being there 3

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ACKNOWLEDGMENTS I would like to thank my committee mem bers, Calogero Dolce, D.D.S., Ph.D., Timothy T. Wheeler, D.M.D., Ph.D. and Sue McGorray, Ph.D. for their guidance and support. I would also like to thank the participating orthodontis ts at the University of Florida, College of Dentistr y and at other academic inst itutions throughout the United States for taking the time to partake in my project. 4

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TABLE OF CONTENTS page ACKNOWLEDG MENTS..................................................................................................4 LIST OF TABLES............................................................................................................6 LIST OF FI GURES..........................................................................................................7 ABSTRACT.....................................................................................................................8 CHAPTER 1 INTRO DUCTION ........................................................................................................10 2 MATERIALS AN D METHOD S...................................................................................13 Data Sa mple ...........................................................................................................13 Investigat ors...........................................................................................................14 Questionna ire.........................................................................................................15 Statistical Analys is..................................................................................................15 3 RESULT S...................................................................................................................17 4 DISCUS SION.............................................................................................................24 5 CONCLUS ION...........................................................................................................28 LIST OF RE FERENCES...............................................................................................29 BIOGRAPHICAL SKETCH ............................................................................................31 5

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LIST OF TABLES Table page 2-1 Questionnaire sent to orthodontists along with the re cords of 159 patients........163-1 Intra-rater agreement compar ison (Percent agreement )....................................213-2 Intra-rater agreement comparison (Kappa st atistic)............................................213-3 Correlation of combined PAR scores and differences between responses........22 6

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LIST OF FIGURES Figure page 3-1 Type of malocclusion dete rmined by inve stigator s.............................................203-2 Arch each investigator would treat......................................................................203-3 Level of difficulty of case s determined by in vestigator........................................203-4 Scatter plot depicting correlation between PAR score and differences between res ponses............................................................................................23 7

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Abstract of Thesis Pres ented to the Graduate School of the University of Florida in Partial Fulf illment of the Requirements for t he Degree of Master of Science CLASS II ETIOLOGY AND ITS EFFECT ON TREATMENT APPROACH AND OUTCOME By David O. Mansour May 2010 Chair: Calogero Dolce Major: Dental Sciences Managing a patient with class II malo cclusion has been an ongoing discussion in orthodontics. The issues are in regards to timing and treatment approach. The Randomized Clinical Trial (RCT) done at the Un iversity of Florida (UF) showed there were no significant skeletal differences between patients treated in two phases versus one phase. Some claim that these results do not correlate to the clinical setting. Purpose: The aim of this study is to determine if orthodontists ag ree within themselves and each other about the etiology, timing and diffi culty of treating patients with a class II malocclusion. Methods : This is a retrospective study, with the patient sample derived from the UF class II study mentioned above. The records were sent to 8 orthodontists, who diagnosed the patients. Within the group of patients, duplicate records of 18 patients were dispersed. Re sults: The orthodontists dec ided that there was both a skeletal and dental component to the patients malocclusion 47.5% of the time. They felt that the mandible would be the arch they would treat 38% of the time. Overall, the raters were consistent within themselves 65% of the time when determining what type of malocclusion the patients possessed, 60% of the time when deciding which arch was 8

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9 at fault when a skeletal imbalance was not ed and 81% of the time when determining need for immediate orthodontic treatment. The raters were consistent 33% and 77% of the time in regards to determining case difficulty and phase-2 treatment need, respectively. There was a small but signifi cant correlation between the consistency of the orthodontists responses and the PAR score Conclusions: When analyzing the duplicate sample of 18 patients, the orthodontists felt that there was both a skeletal and dental component to the malocclusion a majori ty of the time. Th e mandible was most commonly chosen as the arch that would be tr eated. It was also found that the higher the PAR score, the more consistent the ort hodontists were in there diagnoses of the case, this was a relatively low correlati on however. The intra-rater agreement was moderate when determining the etiology of each malocclusion. Due to this insufficient intra-rater agreement, inter-rater agreement wa s not calculated and it was therefore impossible to accomplish one of the original goals of comparing treatment outcomes between patients after the etiology of t he class II malocclusion was determined.

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CHAPTER 1 INTRODUCTION Many factors go into the decision making process for determining the etiology, diagnosis, prognosis and treatment planning of patients with class II malocclusion. Many factors are very subj ective. A class II maloccl usion can originate from discrepancies in the skeleton, dentition or both. The clinician determines if the cause of the imbalance in the maxillary arch, mandibular arch or both. Fo r many years it was widely accepted that if a cla ss II patient had a skeletal im balance, it could be corrected in the mixed dentition with early or phase-1 treatment and then complete the dental correction during phase-2 treatment after all the teeth had erupted. There is little doubt that phase-1 treatment is important for corre ction of certain ort hodontic problems that could cause further harm such as crossbites, impinging overbites, severe crowding or disfiguring malocclusions, but clinicians co ntinue to disagree on treatment timing and approach with patients with a class II malo cclusion even though these questions have been studied with well controlled randomized clinical trials (RCTs). These studies concluded that there are benefit s to early treatment but there is no long term skeletal effect. 1-3 RCTs are considered by many 4 to be the gold standard of clinical research so the class II trials should answer the question s that practitioners have on how we ought to approach treatment of a patient with a cl ass II malocclusion. Many clinicians, however, continue to perform early treatment in order to achieve what they believe is a unique orthopedic effect. Several comment aries have questioned the validity of the class II trials completed at these academic institutions. 5,6 One argument raised is that clinical decisions are not made randomly so the randomization of subjects into the 10

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phase 1 treatment groups, which was done in thes e studies, is not a valid study design. Although they are considered the gold standard for establis hing treatment efficacy, the validity of RCTs and whet her or not one can directly correla te their findings to the real world has been challenged in the past. The author points out that there is much individual variation in terms of response to treatment and states that it is the responsibility of clinicians to identify the patients that can be affected positively by the proposed treatment plan. In other words, practitioners must be able to categorize different patients with a class II malocclus ion based on its etiology and then make the appropriate treatment decision. Clinicians are faced with making diagnosis and treatment planning decisions with every patient and there are various reasons why practitioners will choose one treatment modality over another. Some may have strong personal beliefs about appropriate treatment, while others may not be up to date with current liter ature and finally there can be inconsistent reports in the literature. It can be difficu lt to be consistent with each other and within ourselves, especi ally with the vast amount of literature that is published in the field of orthodontics each year. Baumrind et al 7,8 completed a study which addressed the agreement betw een orthodontists when it comes to the decision of whether or not to extract t eeth on patients and found the clin icians in his study agreed with each other almost 66% of the time. Lee et al 9 completed a project where intrarater and inter-rater agreement between 10 or thodontists treatment planning 60 cases was assessed. They found that the intr a-rater agreement was moderate and the interrater agreement was poor. It appears likely that when clinicians diagnose a complex problem such as a class II malocclusion, consistency may be a concern. The purpose 11

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12 of this study was to determine if orthodontis ts from around the country could agree on the phenotype of the class II malocclusion and the treatment approach of a patient.

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CHAPTER 2 MATERIALS AND METHODS Data Sample This study was retrospective in design us ing the patients that were treated in a previous longitudinal, RCT completed at the University of Florida. 2 The study was designed to determine the effectiveness of tr eating patients with a class II malocclusion via early treatment with a bionator or headgear/biteplane. An observation group was included as well to compare data with the treatment groups. A total of 277 patients began the study with 95 in the bionator group, 100 in the headgear/biteplane group and 82 in the observation group. The two treatm ent groups were comprised of 40% females and the observation group was 36% female. Average age for the headgear/biteplane, bionator, and control groups were 9.7, 9.6, and 9.5, respecti vely. Inclusion criteria featured patients with at least cusp class II molar bilaterally or greater than cusp class II molar unilaterally. The pat ients also required fully erupted 1st molars, positive overjet and overbite, no more than 3 perm anent canines or premolars and good overall dental and general health. For the current study, or thodontic records of 159 patients were sent to 8 orthodontists at various academic institutions throughout the United St ates. Only 159 of the 277 patients were used due to the marginal quality of the initial records of some of the subjects. Within the set of 159 patients, the records of 18 patients were duplicated and peppered throughout the sample randomly. Peer Assessment Rating (PAR) scores were calculated on all of the patients in t he study according to methods previously described. 10 The PAR is a scoring system which rate s the difficulty of a case based on specific criteria. 11 The pre-treatment and post-treatme nt scores were calculated for all 13

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subjects and based on the pre-treatment PAR sco res; the duplicate patients were distributed in order to ensure there was an equal distribution of low, moderate and high PAR scores. Furthermore, the sample of 18 duplicate patients was si milar to the total group in terms of SNA, SNB and ANB. The onl y measure that was significantly different was FMA where standard deviation, minimu m and maximum values are less extreme for the duplicate sample when compared to the total group. The records consisted of intra-oral and extra-oral photos, panoram ic, lateral cephalometric and hand-wrist radiographs and photos of plaster model s. The records were arranged on a PowerPoint presentation, loaded onto a password protected flash drive and mailed to the different orthodontists. Al ong with the records, a questionnaire was sent to be filled out on each patient. Each practitioner re ceived the questionnaires and flash drive and then was instructed to contact me via email for the password in order to begin. The questionnaire, which can be seen in Table 21, included questions aimed at pinpointing the etiology of the class II malocclusi on and whether or not early treatment was necessary in the eyes of the examiner. Investigators Seven of the eight investigators who participa ted in this study are board certified in the United States or t he country where they received thei r orthodontic training. Three of the investigators completed thei r orthodontic training at the Un iversity of Florida. The three remaining investigators who trained in the United States trai ned at the University of Washington, University of Indiana and Vanderb ilt University. The two investigators who trained outside of the United States trained in Korea and Brazil. These 8 investigators currently hold t eaching or adjunct faculty positions at various academic institutions throughout the United States. 14

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Questionnaire Questions were written to extrapolate w hat each orthodontist uses in a set of orthodontic records to determine what the etiology of the malocclusion is and subsequently, how he or she would treat the case. Respondents were told that any extractions of primary teeth, without the placement of appl iances, was not considered immediate orthodontic treatment Any extractions of perm anent teeth with or without the placement of appliances was considered immediate orthodontic treatment (phase1). Any fixed appliances in the mixed de ntition was considered immediate orthodontic treatment (phase-1). Phase2 treatment was defined as fixed appliances in the permanent dentition. So, a person could hav e phase-2 treatment ev en if they had not had phase-1 treatment. Statistical Analysis A kappa statistic was calculated to measure intra-examiner reliability while taking into account the agreement occurring by chance. The strength of agreement is slight when a kappa statistic is 0-0.2; fair between 0.21-0.4, moderate between 0.41-0.6, substantial between 0. 61-0.8 and almost perfe ct between 0.81-1.00. 12 A Spearman correlation test in comparison to the PAR inde x was calculated to test for intra-examiner reliability in relation to case difficulty. 15

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Table 2-1. Questionnaire sent to orthodontists along with the records of 159 patients Subject ID # In vestigator ID # A. What type of malocclusion does this patient demonstrate? 1) Skeletal 2) Dental 3) Both 4) None B. If you determine this case to have a skeletal imbalance, which arch would you treat? 1) Maxilla 2) Mandible 3) Both 4) No Treatment C. Do you believe this patient has a malocclusion requiring immediate orthodontic treatment? 1) Yes 2) If yes, why? 3) No D. How would you rate the difficulty of this case? 14710 E. Do you think it likely a phase 2 treatment would be necessary? 1) Yes 2) Maybe 3) No 16

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CHAPTER 3 RESULTS The orthodontic records of 159 patients from the University of Florida class II study were sent and completed by the eight par ticipating orthodontists. The demographic characteristics and distributi on of the patient sample has been previously described. 13 Since there was poor agreement within (intra-rater) orthodontists in determining the etiology and treatment approach for each pat ient, the aim of the study was changed. The following results are based on the data which was collected from the duplicate patients in the sample. The investigators reported t hat a majority of the pat ients had a combination of skeletal and dental malocclusion as this ans wer was chosen 47.5% of the time, (Figure 3-1). In terms of the arch that each investigator woul d treat, the mandible was chosen 38% of the time, while 37% would not treat ei ther arch (Figure 3-2) Difficulty ratings varied greatly with a score of on a 10 point scale being the most commonly one chosen, approximately about 25% of the time, (Figure 3-3). The intra-rater agreement is depicted in Tabl es 3-1 and 3-2, based on the results from the duplicated pati ents within the sample. Overall, the raters were consistent within themselves 65% of the time when determining what type of malocclusion the patients possessed, 60% of the time when deciding which arch was at fault when a skeletal imbalance was noted and 81% of the time when determining need for immediate orthodontic treatment. The raters were consistent 33% and 77% of the time in regards to determining case difficulty and phase-2 treatment need, respectively. The question regarding case difficulty was answe red on a 10 point scale with 1 being the easiest case and 10 being the most difficul t. The raters answer s on case difficulty 17

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were within +/1 point on the difficulty sca le 42% of the time and were off by more than point 25% of the time. Raters 4 and 8 were least consistent of all the raters in any category with the question regarding case difficulty, with intra-rater agreement being 18%. Raters 4 and 5 were most consistent of all the raters in any category when it came to determining phase-2 treatment need agreeing with them selves 100% of the time. The kappa statistic measures the percent agreement of t he investigators but takes the possibility of chance into account. Overall, the inve stigators had moderate agreement for determining the type of maloccl usion possessed by the patient, deciding which arch was at fault if a skeletal im balance was detected and determining whether or not phase-2 treatment was necessary. Th e kappa statistic ranged from 0.18 to 0.55 with a mean of 0.48 for the rate rs determining the type of malocclusion detected, from 0.13 to 0.60 with a mean of 0.43 for the rate rs determining which arch was at fault and range of 0.10-0.82 with a mean of 0.55 for the raters det ermining whether or not a phase-2 treatment was necessary. When determining need for immediate treatment, the investigators had substant ial agreement within themse lves. The agreement ranged from 0.33-0.87 with a mean of 0.62 among the raters. W hen determining difficulty of each case, the investigators had fair agreem ent. The values ranged from 0.02-0.31 with a mean of 0.21. Raters 4 and 8 were least consistent of all the raters in any category with the question regarding case diffi culty with a score of 0.02 or slight agreement. Raters 4 and 5 were most consist ent of all the raters in any category when it came to determining phase-2 treatment need. Both had perfe ct agreement within themselves in regards to this category. Ov erall, the raters were most consistent with 18

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determining whether or not there was an i mmediate need for orthodontic treatment and least consistent when it came to quantifying case difficulty. Correlation between PAR index and variabilit y of responses was calculated and is displayed in Table 3-3. Again, PAR score was used to determine case difficulty and if that had an effect on the decisions made by t he raters. Overall, the intra-examiner reliability was directly correlated with increa sing PAR score. In other words, the higher the PAR score, the lower the discrepancy there was between the investigators responses. This is indicated by the negat ive Spearmans correlation coefficients. Figure 3-4 plots PAR score versus the sum of the differences of each raters scores. The higher the PAR score indicates a more difficult case. The higher the sum of the differences value, the more inconsistent t he rater was on that particular patient. Conversely, a positive Spearmans correlation coefficient indicates that with increasing PAR score the discrepancy between investig ator responses also increased. Investigator numbers 2 and 8 had positive Spearmans correlation coefficients while the other investigators were all negative. Ther e are no values for in vestigator numbers 4 and 5 in the cells that correspond to phase-2 treatment need because correlation cannot be estimated if there is no variability in response. Both of these investigators responded that all patients r equired phase-2 treatment. 19

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Figure 3-1. Type of malocclusio n determined by investigators. Figure 3-2. Arch each investigator would treat. Figure 3-3. Level of difficulty of cases determined by investigator. 20

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Table 3-1. Intra-rater agreement comparison (Percent agreement). Raters Overall 1 2 3 4 5 6 7 8 Type 65 78 62 61 67 47 61 82 65 Arch 60 72 62 67 50 47 22 82 71 Need 81 78 94 78 67 76 78 88 88 Difficulty: Exact +/1 >1 33 42 25 44 44 11 20 53 27 22 39 39 18 35 47 53 24 24 44 44 11 41 47 12 18 47 35 Phase 2 77 67 69 65 100 100 89 71 59 Table 3-2. Intra-rater agreement comparison (Kappa statistic). Raters Overall 1 2 3 4 5 6 7 8 Type 0.48 0.55 0.33 0.35 0.33 0.18 0.46 0.30 0.47 Arch 0.43 0.47 0.36 0.44 0.34 0.26 0.13 0.30 0.60 Need 0.62 0.56 0.87 0.51 0.33 0.61 0.56 0.72 0.67 Difficulty (weighted) 0.21 0.55 0.21 0.32 0.05 0.34 0.12 0.39 0.02 0.15 0.39 0.31 0.34 0.68 0.12 0.26 0.02 0.48 Phase 2 0.55 0.42 0.39 0.55 --0.82 -0.10 0.27 0.0 0.2 slight agreement 0.2 0.4 fair agreement 0.4 0.6 moderate agreement 0.6 0.8 subst antial agreement 0.8 1.0 almost perfect agreement 21

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Table 3-3. Correlation of combined PAR scores and differences between responses. n type arch immed difficulty ph 2 need sum All Spearman 139 -0.05 -0.09 -0.01 -0.15 -0.10 -0.19* Rater 1 Spearman 18 -0.28 -0.11 -0.27 -0.21 -0.46 -0.29 Rater 2 Spearman 16 0.15 0.17 -0.36 -0.17 0.34 0.15 Rater 3 Spearman 18 0.34 0.44 0.14 -0.07 -0.56* -0.11 Rater 4 Spearman 18 -0.16 -0.44 -0.23 0.15 -0.33 Rater 5 Spearman 17 -0.08 -0.38 0.10 -0.33 -0.42 Rater 6 Spearman 18 -0.38 -0.05 0.22 -0.39 0.04 -0.22 Rater 7 Spearman 17 -0.35 -0.35 -0.15 -0.30 0.08 -0.35 Rater 8 spearman 17 0.33 -0.12 0.43 0.15 0.17 0.39 test of correlation = 0, p< 0.05 22

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23 r = 0.138 0 5 10 15 20 25 30 35 40 012345678 Sum of DifferencesPAR score Figure 3-4. Scatter plot depicting corre lation between PAR score and differences between responses.

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CHAPTER 4 DISCUSSION Recently there has been criticism on t he methodology used in the completed RCTs on effectiveness of early treatment of patient s with a class II malocclusion. The greatest shortcoming of these RCTs was their disregard for the etiology of the class II malocclusion. 5, 6 As a result, the validity of the conclusions of these studies which showed that early treatment had no detectable effect on a patients growth pattern has been questioned. In the current study, eight orthodontists were asked to give the etiology, diagnosis and general treatment plan for 159 patients whose records were taken from the University of Florida class II study. 2 Within the sample, 18 patients were duplicated to assess intra-rater agreement. The practi tioners were asked to decide if the malocclusion was dental and/or skeletal in orig in, which arch they would treat, would they treat immediately, how difficult the ca se was and whether or no t they felt a phase-2 treatment would be necessary. A major findi ng was that the practitioners were not consistent within themselves (intra-rate r agreement) with the etiology and treatment approach of the malocclusion of these patients. Over all the practitioners had 65% agreement when diagnosing the type of malocclusion and 60% agreement when describing which arch was at fault. As a result, the original plan to assess inter-rater agreement could not be completed. Among the many reason for the intra-rater inconsistency was that no guidelines were given for the responses. There are ma ny factors that go into determining the etiology, diagnosis and treatment planning a malocclusion. Some may focus on the occlusion, while other will place greater weight on the prof ile or cephalometric values. 24

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Moreover these factors are in a continuum i.e. molar class II can be from cusp to a full cusp or greater. Given this and the fact that many of these variables are subjective, it is not surprising that there was moderate agreement within a rater. Our results showing inconsistency in t he orthodontists diagnosis and treatment planning has been seen previously in the literat ure. It has been found that orthodontists ar e inconsistent in many diagnostic measures such as determining molar class, and crowding. 14, 15 We did find that there was more agreement in responses as the PAR score increased which is similar to what Lee et al. reported. The difficult cases were easier to identify. It is in the less severe cases where disagreement occurs. These data indicate that there is a si gnificant amount of subjectivity when diagnosing the etiology of a class II maloccl usion making it difficult to be consistent within oneself much less among each other. T here are countless variations of class II phenotypes of patients with a skeletal and/or dental malocclusion. For example, a patient can be class I dentally with an ANB a ngle of 6 or class II dentally with an ANB of 2. One practitioner may like the profile of a specific patient while another practitioner may think he/she is mandibular retrognathic. It is very difficult to randomize a sample into distinct groups when there are so m any variables that ma ke up a class II malocclusion. So while it may sound idealis tic to divide this sample according to etiology, this study has shown that orthodontists do not categorize patients consistently. Another factor for the within rate r inconsistency many be diagnostic thoroughness. 16 This would include the time spent in thoroughly diagnosing a case, such as cephalometric tracing. The cepha lometric measurements were not included with the orthodontic records although the raters were permitted to trac e the radiograph if 25

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they deemed it necessary. The lateral ceph alometric radiograph is often used by a practitioner to determine if the etiology of the Class II malocclusion is skeletal or dental in origin. It is unknown how many ort hodontists trace their lateral cephalometric radiographs to aid in making treatment decisions. It has been shown that a cephalometrics generally do not influence an orthodontists treatment decisions when added to the records. 17 Tracing a cephalogram may not influence treatment decision but would possibly would lead to mo re consistent diagnostic decisions. The many studies that have examined orthodontists clinical reliability both within and between themselves have all shown poor to moderate reli ability whether it was for extraction/nonextraction or like this st udy for diagnosis and treatment planning. 7-9, 14, 18, 19 These inconsistencies have also been attribut ed to diversity in training background and lack of established practice guidelines, i.e. there are many ways that a dental class II malocclusion can be corrected. Finally the orthodontic literature may also be a contribut or to the inconsistencies. Clinicians may not be keeping-up the vast amount of literature that is being disseminated. There are many inconsistencie s in the orthodontic lit erature. Beginning with the many case or retrospective studi es which lack evidence, as described by Sackett et al. 4 and his colleagues, to the results fr om RTC may not have had the clinical significance that orthodontist expected. The published results from the recently completed RCTs on class II treatment are for the average patient, the data also shows that there is a great deal of individual va riation. There have not been any studies to date that show a way to predict which patient s will react favorably to early treatment in terms of altering a patients growth pattern This study showed that the practitioners 26

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who participated were not consistent in the diagnosis of the etiology of malocclusion. In regards the possibility in infl uencing mandibular growth, the fa ct remains that there have not been any well controlled, prospective, randomized human studies that support the fact that we as clinicians can permanent ly alter a patients growth pattern. Some of the limitations of this study include differential interpretation of the questions although measures were taken to pr event this as well as the limited number of investigators from varying backgrounds that were able to participate. 27

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CHAPTER 5 CONCLUSION The results from the RCTs which have exam ined the effects of early treatment for a class II malocclusion, have been challe nged with respect to the idea that randomization should have been completed afte r etiology was determined. In this study, we report that practitioners had m oderate agreement within themselves when determining the etiology, diagnosis and treatm ent plan of a group of patients. They were more consistent in determini ng need for immediate treatment and phase-2 treatment. Intra-rater agr eement improved as the PAR score increased but the correlation was weak. 28

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LIST OF REFERENCES 1. Tulloch JF, Proffit WR, Phillips C. Outcomes in a 2-phase randomized clinical trial of early Class II treatment. Am J Orthod Dentofacial Orthop 2004;125:657667. 2. Dolce C, McGorray SP, Brazeau L, King GJ, Wheeler TT. Timing of Class II treatment: skeletal changes comparing 1-phase and 2-phase treatment. Am J Orthod Dentofacial Orthop 2007;132:481-489. 3. O'Brien K, Wright J, Conboy F, Appelbe P, Davies L, Connolly I et al. Early treatment for Class II Division 1 maloccl usion with the Twin-block appliance: a multi-center, randomized, c ontrolled trial. Am J Or thod Dentofacial Orthop 2009;135:573-579. 4. Sackett DI, Strauss SE, Richardson WS. Evidence-Based Medicine: How to Practice and teach EMB. Philadelphi a, PA: Churchill-Livingstone; 200. 5. Darendeliler M. Validity of Randomized Clinical Trials in Evaluating the Outcome of Class II Treatment. Seminar s in Orthod. 2006;12:67-79. 6. Darendeliler M. Validity of randomized clinical trials in evaluating the outcome of Class II treatments. Or thod Fr 2007;78:303-315. 7. Baumrind S, Korn EL, Boyd RL, Maxwe ll R. The decision to extract: Part 1-Interclinician agreement. Am J Ort hod Dentofacial Orthop 1996;109:297-309. 8. Baumrind S, Korn EL, Boyd RL, Maxw ell R. The decision to extract: part II. Analysis of clinicians' stated reasons for extraction. Am J Orthod Dentofacial Orthop 1996;109:393-402. 9. Lee R, MacFarlane T, O'Brien K. Cons istency of orthodontic treatment planning decisions. Clin Ort hod Res 1999;2:79-84. 10. Pavlow SS, McGorray SP, Taylor MG, Dolce C, King GJ, Wheeler TT. Effect of early treatment on stability of occlusion in patients with Class II malocclusion. Am J Orthod Dentofacia l Orthop 2008;133:235-244. 11. Richmond S, Shaw WC, O'Brien KD, Bu chanan IB, Jones R, Stephens CD et al. The development of the PAR Index (Peer Assessment Rating): reliability and validity. Eur J Or thod 1992;14:125-139. 12. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159-174. 29

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13. Keeling SD, Wheeler TT, King GJ, Garvan CW, Cohen DA, Cabassa S et al. Anteroposterior skeletal and dental changes after early Class II treatment with bionators and headgear. Am J Orthod Dentofacia l Orthop 1998;113:40-50. 14. Luke LS, Atchison KA, White SC. Cons istency of patient classification in orthodontic diagnosis and treatment pl anning. Angle Orthod 1998;68:513-520. 15. Keeling SD, McGorray S, Wheeler TT, King GJ. Imprecision in orthodontic diagnosis: reliability of clinical measures of malocclus ion. Angle Orthod 1996;66:381-391. 16. Lanning SK, Pelok SD, Williams BC, Richar ds PS, Sarment DP, Oh TJ et al. Variation in periodontal diagnosis and treatment planning among clinical instructors. J Dent Educ 2005;69:325-337. 17. Nijkamp PG, Habets LL, Aartman IH, Zentner A. The influence of cephalometrics on orthodontic treatment planning Eur J Orthod 2008;30:630-635. 18. Ribarevski R, Vig P, Vig KD, Weyant R, O'Brien K. Consist ency of orthodontic extraction decisions. Eu r J Orthod 1996;18:77-80. 19. Mandall NA. Are photographic records reliable for orthodontic screening? J Orthod 2002;29:125-127. 30

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31 BIOGRAPHICAL SKETCH David Mansour grew up in Orlando, FL for mo st of his life. He decided to head to Gainesville to attend the University of Florid a in the fall of 1999 to pursue a Bachelor of Science degree in microbiology and cell science. David continued his education in Gainesville by attending dental school t here from 2003-2007 thereby receiving his Doctorate of Dental Medicine. Finally, he received his M.S. in the spring of 2010 by completing the Orthodontics program at the University of Florida.