2012 Fiscal Year Final Research Report
Combined patterns of soft and hard tissue structure in mandibular prognathism
| Project/Area Number |
22792077
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Orthodontic/Pediatric dentistry
|
|---|
| Research Institution | Fukuoka Dental College |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2010 – 2012
|
| Keywords | 顎変形症 / 骨格性下顎前突 / SOM / 自己組織化マップ |
|---|
| Research Abstract |
Combined patterns of soft and hard tissue structure in mandibular prognathismObjectiveThe purpose of this study was to create a self-organizing map (SOM) for visual classification of soft and hard tissue structure in mandibular prognathism, and to demonstrate the typical profiles in mandibular prognathism cases.MethodsThe lateral cephalometric radiographs of 90 female patients (mean age 22.6±3.8 years) with malocclusion were examined. Sixteen soft and hard tissue structurelandmarks were digitized. All points were converted into X-Y values to obtain input vectors for the SOM. By self-organization algorithm, a mandibular prognathism profile map with 4 processing units was calculated. After represent inputting process of vectors, the soft and hard tissue profiles of all the subjects were entered in the map.ResultsAfter ten thousand learning events, the mandibular prognathism profile map with 2× 2 units was calculated, producing 4 virtual profiles. Each virtual profile was character zed by
… More
the degree of facial convexity, facial height, mandibular protrusion, maxillary deficiency, upper and lower lip protrusion, and nasolabial angle.Unit 1 : Hard tissue characteristic features were low mandibular plane angle, mild maxillary deficiency and mandibular protrusion. Soft tissue characteristic features were mild mid-face retardation and protrusion of the chin.Unit 2 : Hard tissue characteristic features were anterior inclination of the mandibularramus and mandibular protrusion with narrowing of nasolabial angle in soft tissue. Unit 3 : Hard tissue characteristic features were high mandibular plane angle and mandibular protrusion. Soft tissue characteristic features were increased lower facial height and protrusion of the chin.Unit 4 : Hard tissue characteristic features were maxillary deficiency, high mandibular plane angle and slight deto-alveolar compensation of upper and lower incisors. Soft tissue characteristic features were increased lower facial height and mild mid-face retardation.ConclusionThe results suggest that this map is useful in establishing visual classification of combined patterns of soft and hard tissue structure based on virtual profiles in mandibular prognathism. Less
|
