title: Clinical implications of recent exodontia before diagnosis of gingival squamous cell carcinoma: A new classification.
abstract: BACKGROUND
  The purpose of this study was to clarify the clinical implications of cases with recent dental extractions to establish a new classification of gingival squamous cell carcinoma (SCC).
  
  
  METHODS
  A total of 156 patients were enrolled in this study. The subjects were divided into 3 groups: type I (dentate; n = 46), type II (edentulous; n = 55), and type III (dental extraction; n = 55). Continuous clinical and treatment variables were analyzed by 1-way analysis of variance (ANOVA) or t test, and categorical variables were evaluated by chi-square tests. Assessment of 5-year survival rates were carried out by the Kaplan-Meier analysis, and the influence of related factors was evaluated by the log-rank test.
  
  
  RESULTS
  The 55 type III patients showed a high probability of bony invasion (80%) and a lower 5-year survival rate (48%) than the other 2 groups.
  
  
  CONCLUSIONS
  Our proposed classification may help clinicians to identify patients with gingival SCC who present with more advanced disease status.
authors.affiliation: Department of Stomatology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Chi-Sheng
authors.initials: CS
authors.lastname: Cheng
authors.affiliation: Department of Stomatology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Chien-Ming
authors.initials: CM
authors.lastname: Chang
authors.affiliation: Department of Stomatology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Ying-Lyung
authors.initials: YL
authors.lastname: Hsiao
authors.affiliation: Department of Oral and Maxillofacial Surgery, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China.|Chung Shan University, Taichung, Taiwan, Republic of China.
authors.forename: Man-Yee
authors.initials: MY
authors.lastname: Chan
authors.affiliation: Department of Stomatology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Chun-Yin
authors.initials: CY
authors.lastname: Lee
authors.affiliation: Department of Stomatology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Li-Tzu
authors.initials: LT
authors.lastname: Lee
authors.affiliation: Department of Oral and Maxillofacial Surgery, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China.|School of Dentistry, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yong-Kie
authors.initials: YK
authors.lastname: Wong
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000401:mortality; D005260:Female; D005887:Gingival Neoplasms / Q000175:diagnosis* / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015996:Survival Rate; D014081:Tooth Extraction / Q000706:statistics & numerical data*
keywords: asymptomatic clinical features; classification; dental extraction; mechanism of bone invasion; squamous cell carcinoma (SCC)