Junji Takehara1, Tomotsugu Takano, Rahena Akhter, Manabu Morita. 1. Department of Preventive Dentistry, Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Nishi 7, Kita 13, Kita-ku, Sapporo 060-8586, Japan. jtake@den.hokudai.ac.jp
Abstract
OBJECTIVES: The purpose of this clinical study was to examine the relationships of v-shaped noncarious cervical lesion (NCCL) formation with occlusal factors. METHODS: A total of 159 male self-defense force officials with a mean age of 36.2 years participated in this study. All present teeth were examined for the presence and type of NCCL using the Tooth Wear Index (TWI). The subjects were then interviewed about bruxing and toothbrushing habit. Finally, occlusal force, occlusal contact area and average pressure were measured using a pressure-detecting sheet. Subject-level logistic regression was carried out to assess the associations of factors with presence of v-shaped NCCL teeth. Subjects without v-shaped NCCL were designated as control subjects. RESULTS: Totally, 4518 teeth were examined. Seventy-eight subjects (49.1%) had one or more teeth with typical v-shaped NCCL (259 teeth). The number of teeth with v-shaped NCCL of grade 2 (defect less than 1mm in depth) was 195 (4.3%), and the number of teeth with v-shaped NCCL of grade 3 (defect 1-2mm in depth) was 54 (1.2%). The prevalence of teeth with v-shaped NCCL was significantly higher in the maxilla than in the mandible. Most of the NCCL teeth were premolars. There was no significant difference between teeth with NCCL on the right side and those on the left side. Subject-level logistic regression analysis revealed that age (OR=1.11), toothbrushing pressure (400g, OR=2.43) and occlusal contact area (>23.0mm(2), OR=4.15) were associated with the presence of NCCL teeth. CONCLUSIONS: It is concluded that aging, toothbrushing pressure and occlusal contact area are associated with the presence of NCCLs.
OBJECTIVES: The purpose of this clinical study was to examine the relationships of v-shaped noncarious cervical lesion (NCCL) formation with occlusal factors. METHODS: A total of 159 male self-defense force officials with a mean age of 36.2 years participated in this study. All present teeth were examined for the presence and type of NCCL using the Tooth Wear Index (TWI). The subjects were then interviewed about bruxing and toothbrushing habit. Finally, occlusal force, occlusal contact area and average pressure were measured using a pressure-detecting sheet. Subject-level logistic regression was carried out to assess the associations of factors with presence of v-shaped NCCL teeth. Subjects without v-shaped NCCL were designated as control subjects. RESULTS: Totally, 4518 teeth were examined. Seventy-eight subjects (49.1%) had one or more teeth with typical v-shaped NCCL (259 teeth). The number of teeth with v-shaped NCCL of grade 2 (defect less than 1mm in depth) was 195 (4.3%), and the number of teeth with v-shaped NCCL of grade 3 (defect 1-2mm in depth) was 54 (1.2%). The prevalence of teeth with v-shaped NCCL was significantly higher in the maxilla than in the mandible. Most of the NCCL teeth were premolars. There was no significant difference between teeth with NCCL on the right side and those on the left side. Subject-level logistic regression analysis revealed that age (OR=1.11), toothbrushing pressure (400g, OR=2.43) and occlusal contact area (>23.0mm(2), OR=4.15) were associated with the presence of NCCL teeth. CONCLUSIONS: It is concluded that aging, toothbrushing pressure and occlusal contact area are associated with the presence of NCCLs.