<%BANNER%>

Occlusal Plane Change as a Predictor for Class II Correction

Permanent Link: http://ufdc.ufl.edu/UFE0024480/00001

Material Information

Title: Occlusal Plane Change as a Predictor for Class II Correction
Physical Description: 1 online resource (26 p.)
Language: english
Creator: Metz, John
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: class, clockwise, counter, ii, occlusal, plane, rotation
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: The aim of this study is to correlate occlusal plane inclination change with molar and canine classification correction. Methods: The subjects for this retrospective study had participated in a prospective, longitudinal, randomized clinical trial designed to examine the effectiveness of early treatment with headgear/biteplane (H) or a bionator (B), compared to observation (O), among subjects with a Class II malocclusion. The occlusal plane changes were measured as angular changes in relation to cephalometric planes. Dental casts were used to score molar and canine classification from 0 to 10, with most in the range of 1 to 5 (1= full cusp class II and 5 = class I). Data were collected at the start of treatment (DC1) and at various time-points until the end of treatment (DCF). Results: These data indicate that changes in molar and canine classification over the course of treatment did not differ significantly for those with bionator or headgear early treatment or adolescent comprehensive treatment. A mean counterclockwise movement of the occlusal plane was observed in this sample of treated Class II subjects. Conclusion: Angular changes as measured to the occlusal plane were small and were not correlated with the changes in molar and canine classification
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 John Metz.
Thesis: Thesis (M.S.)--University of Florida, 2009.
Local: Adviser: Dolce, Calogero.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-05-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0024480:00001

Permanent Link: http://ufdc.ufl.edu/UFE0024480/00001

Material Information

Title: Occlusal Plane Change as a Predictor for Class II Correction
Physical Description: 1 online resource (26 p.)
Language: english
Creator: Metz, John
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: class, clockwise, counter, ii, occlusal, plane, rotation
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: The aim of this study is to correlate occlusal plane inclination change with molar and canine classification correction. Methods: The subjects for this retrospective study had participated in a prospective, longitudinal, randomized clinical trial designed to examine the effectiveness of early treatment with headgear/biteplane (H) or a bionator (B), compared to observation (O), among subjects with a Class II malocclusion. The occlusal plane changes were measured as angular changes in relation to cephalometric planes. Dental casts were used to score molar and canine classification from 0 to 10, with most in the range of 1 to 5 (1= full cusp class II and 5 = class I). Data were collected at the start of treatment (DC1) and at various time-points until the end of treatment (DCF). Results: These data indicate that changes in molar and canine classification over the course of treatment did not differ significantly for those with bionator or headgear early treatment or adolescent comprehensive treatment. A mean counterclockwise movement of the occlusal plane was observed in this sample of treated Class II subjects. Conclusion: Angular changes as measured to the occlusal plane were small and were not correlated with the changes in molar and canine classification
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 John Metz.
Thesis: Thesis (M.S.)--University of Florida, 2009.
Local: Adviser: Dolce, Calogero.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2011-05-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0024480:00001


This item has the following downloads:


Full Text

PAGE 1

1 OCCLUSAL PLANE CHANGE AS A PREDICTOR FOR CLASS II CORRECTION By JOHN J. METZ A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SC IENCE UNIVERSITY OF FLORIDA 2009

PAGE 2

2 2009 John J. Metz

PAGE 3

3 To Melissa and Grace, for bringing me peace

PAGE 4

4 ACKNOWLEDGMENTS I would like to thank my committee members, Timothy T. Wheeler D.M.D., Ph.D.; Calogero Dolce D.D.S., Ph.D.; and Sue McGorray Ph.D.; for their guidance and direction. I would also like to thank Leandra Dopazo, D.D.S., M.S. for her assistance in the calibration process. Finally, I would like to acknowledge grants from the Southern Association of Orthodontists and the University of Florida Graduate Student Council.

PAGE 5

5 TABLE OF CONTENTS page ACKNOWLEDGMENTS .................................................................................................................... 4 LIST OF TABLES ................................................................................................................................ 6 LIST OF FIGURES .............................................................................................................................. 7 ABSTRACT .......................................................................................................................................... 8 CHAPTER 1 INTRODUCTION ......................................................................................................................... 9 2 METHODS .................................................................................................................................. 12 3 RESULTS .................................................................................................................................... 15 4 DISCUSSION .............................................................................................................................. 20 5 CONCLUSION ........................................................................................................................... 23 LIST OF REFERENCES ................................................................................................................... 24 BIOGRAPHICAL SKETCH ............................................................................................................. 26

PAGE 6

6 LIST OF TABLES Table page 3 1 Sample c haracteristics ............................................................................................................ 16 3 2 Angular changes referenced to occlusal plane, initial to end of p hase I ............................. 16 3 3 Angular change, initial to end of phase I by treatment group ............................................. 17 3 4 Correlation coefficients of change in classification and a ngul ar c hanges .......................... 17 3 5 Correlation coefficients for angular changes, initial to f inal ............................................... 17

PAGE 7

7 LIST OF FIGURES Figure page 2 1 Cephalometric l andmarks ...................................................................................................... 14 3 1 Angular changes in relation to occlusal p lane from DC1 to DCF ...................................... 18 3 2 Treatment success m easured by canine classification s core ............................................... 19

PAGE 8

8 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science OCCLUSAL PLANE CHANGE AS A PREDICTOR FOR CLASS II CORRECTION By John J. Metz May 2009 Chair: Calogero Dolce Major: Dental Sciences Introduction: The aim of this study is to correlate occlusal plane inclination change with molar a nd canine classification correction. Methods: The subjects for this retrospective study had participated in a prospective, longitudinal, randomized clinical trial designed to examine the effectiveness of early treatment with headgear/biteplane (H) or a b ionator (B), compared to observat ion (O), among subjects with a C lass II malocclusion. The occlusal plane changes were measured as angular changes in relation to cephalometric planes. Dental casts were used to score molar and canine classification from 0 to 10, with most in the range of 1 to 5 (1= full cusp class II and 5 = class I). Data were collected at the start of treatment (DC1) and at various time -points until the end of treatment (DCF). Results: These data indicate that changes in molar and canine classification over the course of treatment did not differ significantly for those with bionator or headgear early treatment or adolescent comprehensive treatment. A mean counterclockwise movement of the occlusal plane was observed in this sample of tre ated Class II subjects. Conclusion: Angular changes as measured to the occlusal plane were small and were not correlated with the changes in molar and canine classification

PAGE 9

9 CHAPTER 1 INTRODUCTION The treatment of malocclusion in orthodontics involves ca reful diagnosis, thorough treatment planning, and execution of technique that guides and corrects both the mature and growing dentofacial structures. Therefore, the orthodontist must understand the significant growth changes that occur in their patients a nd relate the changes to occlusion, skeletal relationships and facial profiles. Specifically, in the treatment of jaw discrepancies in the sagittal plane such as those seen in Class II or C lass III malocclusions, it has been stated that control of the occ lusal plane can facilitate molar classification correction .1 In addition to the relationship of the jaws, the inclination of the occlusal plane also influences facial esthetics, dental fun ction and occlusion. Therefore, management of occlusal plane inclination should be a fundamental component of orthodontic treatment. The occlusal plane is usually described on a cephalogram as moving in a steepening (clockwise) or flattening (countercloc kwise) rotation. Occlusal plane inclination is determined by normal growth and by the mechanics used to treat malocclusions. Bjrk and Skieller showed that maxillary growth was not only characterized by anterior inferior displacement, but also a forward rotation accompanied by a descent of the upper molar region and a simultaneous forward mandibular rotation.2 Therefore, rotational growth of the maxilla will cause a counterclockwise movement. With similar results, Riolo et al. found in a serial cephalometric study of untreated subjects that natural changes caused the Downs occlusal plane to rotate counterclockwise a mean of 6.15 degrees between the ages of 6 and 16 years 3. Creekmore and Schudy showed that maxillary molars erupt more than the maxillary incisors, whereas mandibular incisors erupt more than the mandibular molars .4 5 These vertical changes explain the counterclockwise rotation of the occlusal plane during growth. Lux and Kim not only described the occlusal plane changes but related their influences on the sagittal d imension .6

PAGE 10

10 7 Both authors reported a counterclockwise rotation of the o cclusal plane in untreated groups with good occlusion. Orthodontic treatment mechanics can be used to manipulate the inclination of the occlusal pl ane. Proffit states that in a C lass II situation, if upper posterior teeth are prohibited from erupting and moving forward, while the lower posterior teeth are erupting occlusally and forward, the resulting rotation of the occlusal plane and forward movement of the dentition will contribute to correction of the C lass II molar relationship .1 The upward and forward movement of the mandibu lar molar can be achieved with C lass II elastics; this will establish the posterior occlusal plane at a higher level, a clockwise rotation of the occlusal plane. Braun and Legan developed a method to define the geometric and mathematical relationships between dental occlusion and rotations of the occlusal plane in the sagittal dimension.8 Their main conclusion was that for each degree of rotation of the occlusal plane, a half millimeter change in the dental occlusal relationship was found and reasoned that a clockwise rota tion would result in a C lass II to C lass I change. On the contrary, Sato describes a counterclockwise rotation of the occlusal plane for a Class II correction using the Multiloop Edgewise Archwire (MEAW) appliance .9 The MEAW technique is predicated on diagnosis of the pre -existing occlusal plane and the therapy aims to reconstruct the occlusal plane based on whether a Class II or Class III correction is needed. Numerous case reports by Sato show a counterclock wise of the occlusal plane for c lass II correction. In addition, Lamarque and Thompson also documented counterclockwise changes in the occlusal plane of their treated patients .10 11 It has been shown that two major theories on the change of occlusal plane inclination exist. The review o f the literature on occlusal plane change due to growth supports an age -related

PAGE 11

11 counterclockwise change. A dichotomy exists in regards to thinking of occlusal plane inclination change during orthodontic treatment. The purpose of this study was to analyze longitudinal cephalometric radiographs of a large sample to discern if a predictor exists between occlusal plane inclination change and molar and canine correction.

PAGE 12

12 CHAPTER 2 METHODS The subjects for this retrospective study participated in a prospectiv e, longitudinal, randomized clinical trial designed to examine the effectiveness of early treatment with headgear/biteplane (H) or a bionator (B), compared to observat ion (O), among subjects with a Class II malocclusion. Details of the study have been pre viously published .12 The subjects were stratified before random assignment into one of three groups. St rata included sex, severity of Class II, and severity of initial mandib ular plane angle. Severity of C lass II malocclusion was classified as mild i f they had bilateral half -cusp C lass II, moderate if at least o ne side was three fourths cusp C lass II and severe if at least o ne side was full cusp C lass II. Severity of initial mandibular plane angle was classified into three groups; less than thirty degrees, between thirty and forty degrees, and greater than forty degrees. Longitudinal cephalometric radiographs were collected at baseline (DC1), at the end of early C lass II treatment (DC3) or observation (DC4), at the beginning of fixed applianc es (DC7), and at the end of orthodontic treatment (DCF) The cephalograms were traced and digitized by a single calibrated examiner as reported in a previous article .13 The landmarks used for the current study are shown in Figure 2 1. The sella nasion (SN) plane was constructed from 1) sella and 2) nasion. T he Fran kfort h orizontal (FH) plane was constructed from 3) porion and 4) orbitale. The palatal plane (PP) was constructed from 5) posterior nasal spine and 6) anterior nasal spine. The occlusal plane (OP) was constructed from 7) posterior mean functional occlus al plane and 8) anterior mean functional occlusal plane. Finally, the mandibular plane (MP) was constructed from 9) gonion and 10) gnathion. Dental casts were used to score molar and canine classification and overjet (upper right central incisor to lower right central incisor) by a single calibrated examiner. The examiner was

PAGE 13

13 trained by two faculty orthodontists and intra and inter rater reliability was assessed. For intra rater comparison, over 98% of calls were within plus/minus one category, with exa ct agreement ranging from 70 to 85%. For inter rater comparisons, over 93% of calls were within plus/minus one category, with exact agreement ranging from 54 to 85%. The canine and molar classification scale was measured in quarter cusp increments from 0 to 10, with most scores in the range from 1 to 5 (1= full cusp C lass II and 5 = C lass I). The scores were then added together to get a total score (TS) (bilateral cla ss I molar and canine TS = 20). Data were collected at the start of treatment (DC1), the end of phase I or 2 years (DC3 or DC4 ), during phase II treatment (DC7) and at the end of treatment (DCF). The data was then analyzed c omparing the angle s formed by the planes identified in Figure 1 with the occlusal plane for each time point T he c lassification data was also compared to angular changes to determine if a correlation exists between molar and canine classification and change in occlusal plane inclination. Statistical Analysis : Chi -square tests of association were used to test for samp le characteristic differences between early treatment groups. Paired t -tests were used to test for differences in angular measurements over time. Analysis of variance was used to test for treatment group differences with regard to changes in the angular measures over time. Pearson correlation coefficient estimates were used to examine correlation between angle changes, and canine classification and overjet changes. A p -value less than 0.05 was considered statistically significant

PAGE 14

14 Fig ure 2 1. Cepha lometric l andmarks 1) sella 2) nasion 3) porion 4) orbitale 5) posterior nasal spine 6) anterior nasal spine 7) posterior mean functional occlusal plane 8) anterior mean functional occlusal plane 9) gonion 10) gnathion. Planes: sella -n asion pl ane (SN), Frankfort horizontal plane (FH), palatal plane (PP), occlusal plane (OP), mandibular plane (MP)

PAGE 15

15 CHAPTER 3 RESULTS Overall, 325 subjects were randomized and baseline data were available for 277 subjects. The sample characteristics are shown in Table 3 1 and include subjects that had canine classification scores at DC3/4 or DCF The original sample experienced attrition during the study period; therefore not all subjects had data at the initial and final time points. The total numbe r of subject s studied was 2 59 and did not differ significantly by tre atment group, sex, severity of C lass II, or i nitial mandibular plane angle. The predominant racial origin of the sample was white. Two time periods of interest were created to analyze the data; time period 1 included DC1 to DC3/4 data (n = 259) and time period 2 included data DC1 to DCF (n = 211). All planes were referenced to the occlusal plane for analysis and the angular changes for time period 1 are shown in Table 3 2. The changes were significant for SN -OP, FH OP, PP OP, and SN -MP; but they were less than one degree. Furthermore, when looking at angular changes by treatment group in time period 1, small but significant changes were observed. Table 3 3 illustrates that the headgear treatment group ha d significant changes for the SN OP angle and FH OP angle; an increase of 0.76o and 0.87o respectively Also, the headgear group had significant changes in the SN MP angle, an increase of 1.11o. The bionator treatment group had significant changes for the FH OP angle, it increased 0.48o. Finally, the observation group had significant changes for the PP OP angle, it decreased 0.24o. Time period 2 measured both phase 1 and phase 2 treatment. The mean angular changes for each plane referenced to occl usa l plane are shown in Figure 3 1 The SN OP, FH OP, PP OP, and SN -MP all exhibited a decrease or counterclockwise movement in their angular measurements. In contrast, the MP OP angle exhibited an increase or clockwise movement during the complete treatmen t period.

PAGE 16

16 Treatment success, as measured by canine classification (Maximum score = 10) was observed to be high with 86% of subjects scoring 8 or higher (Figure 3 2 ). To account for upper premolar extraction patients, both canine and molar classificatio n scores are reported. Overall, no significant differences were noted in occlusal plane angular changes when compared to the change in canine classification (Table 3 4). A significant correlation was found between canine classification and overjet. Tabl e 3 5 illustrates the correlations of the angle changes from initial to final; all angular changes were significant with each other at a level of p<0.01 Table 3 1. Sample c haracteristics Bionator Headgear Observation Total P Value Total Patients 86 93 80 259 Sex (Male) 52 (60%) 56 (60%) 50 (63%) 158 0.9464 (Female) 34 (40%) 37 (40%) 30 (38%) 101 Severity Severe Moderate Mild 39 (45%) 24 (28%) 23 (27%) 42 (45%) 29 (31%) 22 (24%) 37 (46%) 23 (29%) 20 (25%) 118 76 65 0.9856 MPA <30o 30o40o >40o 21 (24%) 57 (66%) 8 (9%) 24 (26%) 63 (68%) 6 (6%) 18 (23%) 56 (70%) 6 (8%) 63 176 20 0.9441 Total number (percentage); c hi -square test of association Table 3 2. Angular changes re ferenced to occlusal plane, initial to end of p hase I Initial End Phase I Change P value SN OP angle 19.8 o (4.0) 20.1 o (4.0) 0.3 o (1.4) 0.0009 FH OP angle 7.5 o (3.8) 8.0 o (3.9) 0.4 o (1.7) <0.0001 PP OP angle 12.0 o (3.7) 11 .9 o (3.8) 0.1 o (0.6) 0.0405 MP OP angle 16.1 o (3.8) 16.1 o (4.0) 0.0 o (2.0) 0.83 SN MP angle 36.0 o (5.1) 36.3 o (5.5) 0.3 o ( 1.9) 0.0064 Mean (standard deviation) sample size (n=234); p aired t tests

PAGE 17

17 Table 3 3. Angul ar change, initial to end of phase I by treatment group Bionator (n=82) Headgear (n=90) Observation (n=62) P value^ SN OP angle 0.20 o 0.76 o 0.20 o < 0.0001 FH OP angle 0.48 o 0.87 o 0.20 o 0.0007 PP OP angle 0.01 o 0.05 o 0.24 o 0.09 00 MP OP angle 0.40 o 0.35 o 0.12 o 0.0403 SN MP angle 0.20 o 1.11 o 0.08 o < 0.0001 Mean; *p aired t test (within groups, differences from zero), ^ ANOVA ( comparing groups ) Table 3 4 Correlation coefficients of change in classification and angular c hanges DC1 to End of Early Treatment *0.57 0.25 0.23 0.05 0.02 0.16 Bionator *0.57 0.08 0.00 0.01 0.01 0.07 Headgear *0.53 0.22 0.22 0.12 0.02 0.14 Observation 0.19 0.05 0.06 0.03 0.19 0.21 DC1 to F OJ *0.56 0.00 0.04 0.03 0.14 0.15 Bionator *0.57 0.02 0.04 0.11 0.06 0.07 Headgear *0.51 0.01 0.10 0.00 0.15 0.18 Observation *0.58 0.02 0.01 0.16 0.21 0.21 Pearson correlation c oefficient, p -value <0.0001 Table 3 5 Correlation coefficients for angular changes, initial to f inal *0.74 *0.68 0.55 *0.46 *0.58 0.55 *0.19 0.41 *0.28 *0.49 Pearson correlation coefficient, s ample size (n=200); s ignificance p<0.01

PAGE 18

18 Figure 3 1. Angular changes in relation to occlusal p lane from DC1 to DCF Arrow down corresponds with a decrease in degrees and counterclockwise movement (SN OP, FH OP, PP OP, SN -MP). B) Arrow up corresponds wit h an increase in degrees and clockwise movement (MP OP).

PAGE 19

19 0 10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10 Canine Classification Score Frequency Initial End of Phase I Final Figure 3 2. Treatment success measured by canine classification s core Right and left canine classificati on measured 1 to 5. Bilateral c lass I canine would be scored 10.

PAGE 20

20 CHAPTER 4 DI SCUSSION The sample was evenly distributed and provided an excellent opportunity to retrospectively evaluate the effects of C lass II treatment on the occlusal plane. Two time periods were created to correct for patient dropout; this also allowed the occl usal plane changes to be examined during phase 1 and phase 2 orthodontic treatment. Molar classification scores were collected and analyzed separately because some subjects received extraction of upper premolars to correct the C lass II malocclusion. Even though statistically significant changes were demonstrated in Table 3 -2 and Table 3 3 it should be noted that these changes were less than one degree. The sample size was large overall, so there was a large amount of statistical power to detect small ch anges. Although the angular changes were smal l, close examination of Figure 3 1 shows that the overall mean movement of the occlusal plane is counterclockwise. The angles above the occlusal plane all decreased and the angle below the occlusal plane (MP O P) increased. It was shown that the angular changes were not correlated with canine classification change, but the trend of counterclockwise movement would be in agreement with the results of Sato, Lamarque and Thompson .911 Further the angular changes described in Table 3 5 were correlated with each other and also support a counterclockwise movement, with the positive correlations between SN OP and FH OP and the negative correlations with MP OP. It is well established that a surgical posterior maxillary impaction will result in autorotation of the mandible and a resultant forward position of the mandible in the sagittal dimension .14 The oral and maxillofacial surgery community has recognized that the changes in the occlusal plane are a consequence of the surgical rotation of the jaws and not the inherent goal of orthognathic surgery; however they evaluate the rotation of the occlusal plane in thei r pre -

PAGE 21

21 surgical planning.15 In this same manner, there has been a recent recommendation to include a more comprehensive evaluation of the occlusal plane in the diagnosis of malocclusion .16 The results of this study show that there is not a correlation between angular changes of the occlusal plane and canine classification correction. However, this sample population was treated with a functional C lass II applianc e (b ion ator ), headgear, or the use of c lass II elastics. It is possible that evaluating treated samples of other clinicians such as those that routinely use the MEAW technique, a correlation could be found between occlusal plane inclination and c lass II correction. It would be interesting to evaluate the dif ferent mechanics used to treat c lass II malocclusion to discern if different treatment modalities affect the occlusal plane in different ways. For example, use of class II elastics may result in more clockwis e change by positioning the mandibular molars in a higher vertical position. In the same manner, the use of headgear restricts the downward descent of the maxillary molar and could impose more of a clockwise change. In contrast, the MEAW technique aims t o intrude both maxillary and mandibular molars in the beginning of therapy and then aims to position the maxillary molar in a more down and forward position thus imposing a counterclockwise rotation of the occlusal plane and a resultant forward adaptation of the mandible in the correction of C lass II malocclusions .9 As expected, the study population exhibited a significant change in overjet which was positively correlated with canine classification correction (Table 3 4). Further, as shown in Figure 3 2 an overall trend towards C lass I was exhibited by 86% of the sample. Therefore, this population did in fact exhibit C lass II correction; however it was not demonstrated to be significantly correlated with occlusal plane inclination. This study measured canine classification as the treatment outcome to be desired. Angles molar and canine classification

PAGE 22

22 should be considered as a measurement gathered from with the maxillomandibular complex. Another possible way to evaluate the success of C lass II treatment would be the anteroposterior position of the mandible, a measurement gathered on the mandible itself. Further research should be conducted to evaluate the effect of occlusal plane inclination on the sagittal position of the mandible.

PAGE 23

23 CHAPTER 5 CONCLUSION This retrospective study of a large Class II patient population evaluated the impact of treatment effects of C lass II correction on the occlusal plane. It was shown the angular changes measured to the occlusal plane were small and not significantly correlated with canine classification correctio n. However, an overall trend of counterclockwise movement of the occlusal plane was exhibited by these study participants during orthodontic treatment. Further research is needed to evaluate specific treatment mechanics to discern if those modalities aff ect the occlusal plane in ways different than what was observed in this study.

PAGE 24

24 LIST OF REFERENCES 1 Proffit WR, Fields HW. Contemporary orthodontics. St. Louis: Mosby; 2000. 2 Bjork A, Skieller V. Facial development and tooth eruption. An implant study at the age of puberty. Am J Orthod 1972;62:339383. 3 Riolo ML, R. M, McNamara J, Hunter WS. An Atlas of Craniofacial Growth: Cephalometric Standards from the University School Growth Study. Ann Arbor: The University of Michigan; 1974. 4 Creekmo re TD. Inhibition or stimulation of the vertical growth of the facial complex, its significance to treatment. Angle Orthod 1967;37:285297. 5 Schudy FF. The control of vertical overbite in clinical orthodontics. Angle Orthod 1968;38:1939. 6 Lux CJ, Burden D, Conradt C, Komposch G. Age related changes in sagittal relationship between the maxilla and mandible. Eur J Orthod 2005;27:568578. 7 Kim YE, Nanda RS, Sinha PK. Transition of molar relationships in different skeletal growth patterns. Am J Orthod Dentofacial Orthop 2002;121:280290. 8 Braun S, Legan HL. Changes in occlusion related to the cant of the occlusal plane. Am J Orthod Dentofacial Orthop 1997;111:184188. 9 Sato S, Akimoto S, M. A, S. A, Y. J. MEAW Orthodontic Therapy Using Multiloop Edgewise Arch Wire. Daiichi Shika Publications; 2001. 10. Lamarque S. The importance of occlusal plane control during orthodontic mechanotherapy. Am J Orthod Dentofacial Orthop 1995;107:548558. 11. Thompson WJ. Occlusal plane and overbite. Angle Orthod 1979;49:4755. 12. Wheeler TT, McG orray SP, Dolce C, Taylor MG, King GJ. Effectiveness of early treatment of Class II malocclusion. Am J Orthod Dentofacial Orthop 2002;121:917. 13. Dolce C, McGorray SP, Brazeau L, King GJ, Wheeler TT. Timing of Class II treatment: S keletal changes comparing 1 -phase and 2 -phase treatment. Am J Orthod Dentofacial Orthop 2007;132:481489. 14. Wessberg GA, Washburn MC, LaBanc JP, Epker BN. Autorotation of the mandible: effect of surgical superior repositioning of the maxilla on mandibular resting posture. Am J Orthod 1982;81:465472.

PAGE 25

25 15. Reyneke JP, Bryant RS, Suuronen R, Becker PJ. Postoperative skeletal stability following clockwise and counter -clockwise rotation of the maxillomandibular complex compared to conventional orthognathic treatment. Br J Oral Maxillofac Surg 2007;45:5664. 16. Tanaka EM, Sato S. Longitudinal alteration of the occlusal plane and development of different dentoskeletal frames during growth. Am J Orthod Dentofacial Orthop 2008;134:602 e601611; discussion 602603.

PAGE 26

26 BIOGRAPHICAL SKETCH John J. Metz r eceived his Bachelor of Science in b iology in 2002 from Indiana Un iversity in Bloomington He continued his education at the University of Florida Col lege of Dentistry in Gainesville and earned his Doctorate of Dental Medicine in 2006. This thesis is a p artial requi rement for the degree of Master of Science in Dental Sciences, Orthodontics. He received his M.S. from the University of Florida in the spring of 2009.