The effects of curve of spee in skeletal class II patients treated with combined orthodontics and surgery
| dc.contributor.author | Kuo, Ping-Hsiang | |
| dc.contributor.examiningcommittee | Tsang, Susan (Preventive Dental Science) | en_US |
| dc.contributor.examiningcommittee | Mcfadden, Leland (Dental Diagnostic and Surgical Sciences) | en_US |
| dc.contributor.supervisor | Drummond, Robert | |
| dc.date.accessioned | 2022-07-25T21:21:31Z | |
| dc.date.available | 2022-07-25T21:21:31Z | |
| dc.date.copyright | 2022-07-25 | |
| dc.date.issued | 2021-09-02 | |
| dc.date.submitted | 2022-07-25T19:25:45Z | en_US |
| dc.degree.discipline | Preventive Dental Science (Orthodontics) | en_US |
| dc.degree.level | Master of Science (M.Sc.) | en_US |
| dc.description.abstract | Purpose: To perform a retrospective study with the question: Is there a significant correlation between pre-surgical Curve of Spee (COS) and skeletal changes from mandibular bilateral sagittal split osteotomy (BSSO) advancement surgery? Furthermore, in skeletal Class II patients, does initial mandibular plane angle (MPA) make a difference? Methods: The sample was made up of a group of patients who underwent a single surgical procedure of mandibular BSSO advancement and divided into three groups by mandibular plane angle (MPA). Pre-surgical Curve of Spee (COS) was measured on digital dental models and correlated with skeletal changes from pre-surgical and post-surgical cephalograms using Spearman rank-order analysis. Paired T-test was utilized to identify statistical significance. Regression analysis was performed to estimate the cephalometric change per unit of pre-surgical COS. P-value was set at 0.05. Results: The sample was composed of 90 subjects; divided into 3 groups: (1) high-MPA (MPA 34.10 ± 3.23°; aged 26.28 ± 17.66 years; n = 30) (2) medium-MPA (MPA 27.85 ± 1.61°; aged 22.04 ± 11.40 years; n = 30) (3) low-MPA (MPA 20.91 ± 3.20°; aged 26.84 ± 15.58; n = 30). Statistical significance was found between pre-surgical Curve of Spee (COS) and both linear and percentage changes of lower face height (LFH) in the low-MPA group (p < 0.001). The estimated relationship between COS and LFH was that for each 1mm pre-surgical COS, there was an increase in LFH of 1.629 mm from the surgical procedure (p = 0.000). Conclusion: Pre-surgical Curve of Spee is significantly correlated with surgical changes in lower face height in low-MPA subjects. The quantified ratio between them could be applied in simulating surgical outcome clinically. | en_US |
| dc.description.note | October 2022 | en_US |
| dc.identifier.uri | http://hdl.handle.net/1993/36632 | |
| dc.language.iso | eng | en_US |
| dc.rights | open access | en_US |
| dc.subject | Curve of Spee | en_US |
| dc.subject | Skeletal Class II | en_US |
| dc.title | The effects of curve of spee in skeletal class II patients treated with combined orthodontics and surgery | en_US |
| dc.type | master thesis | en_US |
| local.subject.manitoba | no | en_US |