Mandibular Anterior Crowding and Periodontal Status

Objective: To assess the relationship of mandibular anterior crowding (MAC) to periodontal status over short and long term. Methods: 162 male dentate subjects in the VA Dental Longitudinal Study (DLS) with MAC at the study baseline were selected. Plaque, calculus, gingival bleeding on probing (BoP), and periodontal probing depth (PPD) were measured. Alveolar bone loss was assessed by using Periapical radiographs with Schei ruler method. MAC was determined from casts and defined as the difference between the sum of mesio-distal dimensions of mandibular incisors and the intercanine dimension. Subjects were categorized by baseline MAC severity into 4 groups. Average follow-up was 7 years (range 2-12 years). Results: There were no significant baseline differences among the four MAC groups in age, tobacco use or oral hygiene habits. Compared to subjects with no MAC, those with any MAC had higher odds of having more teeth with high plaque score at baseline (OR =2.6, p <0.01) and at follow-up (OR = 2.0, p <0.01), and severe MAC was associated with higher odds of having teeth with high calculus score at baseline (OR=2.7, p=0.05). Subjects with MAC had higher odds of having more teeth with BoP at baseline (OR=1.9, p=0.05) and at follow-up (OR=2.2 p=0.04), and higher odds of teeth with PPD> 3mm at follow-up (OR= 2.9, p=0.03). Over the follow-up period, there was a significant (p<0.001) relationship between increase in MAC and increase in alveolar bone loss. Conclusion: Mandibular anterior crowding is associated with increased likelihood of plaque and calculus accumulation and BoP. Severe crowding was associated with an increase over time in PPD and bone loss. This study was supported by the U.S. Department of Veterans Affairs and NIDCR grant # K24 DE00419