|
KMID : 0362220130400030195
|
|
Journal of The Korean Research Society for Dental Materials
2013 Volume.40 No. 3 p.195 ~ p.204
|
|
|
Evaluation of the relationship between Monson’s sphere and arch form and cusp angle using three-dimensional reconstruction method
|
|
Nam Shin-Eun
Lee Seung-Pyo
|
|
|
Abstract
|
|
|
|
Monson’s sphere has been used as a reference for prosthetic reconstruction of the posterior dentition. Recent studies have reported that the radius of Monson’s sphere differs greatly in individuals, but little researches has been conducted on factors related to the Monson’s sphere. Therefore, this study aimed to generate Monson’s sphere using newly developed algorithm and evaluate the relationship between the Monson’s sphere and correlated factors. Mandibular dental casts from 71 young adult Korean were scanned and rendered as virtual dental models with a 3-D scanner. Twenty and six landmarks were digitized on the virtual dental models using a custom made software program. The Monson’s sphere was estimated by fitting a sphere to the cusp tips using a least-squares method. Using specialized software program, arch radius, arch angle, arch length, arch width and buccolingual cusp angle of mandibular posterior teeth were measured. Mann-Whitney Test were performed to test gender difference and correlation coefficients were investigated to verify the correlation between Monson’s sphere and correlated factors (a=.05). The mean radius of the sphere was 111.47 mm (4.39 inch). There was significantly difference between males and females in the radius (p<.001). Arch angle in canine (ICA), arch length (IIC, IIM), arch width (ICW, IMW) and all buccolingual cusp angle measurements (CA) except for left first premolar were correlated to the radius of Monson’s sphere, respectively (p<.05). Especially, buccolingual cusp angles of molar showed the highest correlation coefficients among the factors, with ? 0.533 - -0.276 (p<.05). It was concluded that the radius of Monson’s sphere was greater than the classical 101.06 mm (4 inch) value and buccolingual cusp angles of molar can be considered as one of the main factors correlating with the radius of Monson’s sphere.
|
|
|
KEYWORD
|
|
|
Arch form, Cusp angle, Monson’s sphere, Virtual dental models
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
|
|