Effects of different tooth sites and ages on the remodeling patterns of human mandibular alveolar bone

OBJECTIVES: This study aimed to investigate the effects of tooth sites (incisors, canines, premolars, molars) and aging on the remodeling patterns of the human mandibular alveolar bone, including the buccal cortical bone, lingual cortical bone, and cancellous bone. METHODS: A total of 600 eligible patients (300 males and 300 females, aged 20-80 years) were randomly selected from the Stomatological Hospital of Xi'an Jiaotong University between January 2023 and December 2024. All subjects underwent cone-beam computed tomography (CBCT) scans using a Planmeca ProMax 3D scanner. They were stratified into age groups (20-29 to 70-80 years, in 10-year intervals) and by tooth position (incisors, canines, premolars, molars). The measurement plane was standardized using InVivoDental 7 software. Cortical bone thickness was measured as the average of six points on both the buccal and lingual sides below the root apex. Cancellous bone density was analyzed using threshold analysis in ImageJ software. RESULTS: The results indicated that within the same age group, the buccal cortical bone thickness followed a distinct pattern across different tooth positions: molars (LM) > premolars (LP) > canines (LC) > incisors (LA). In contrast, no clear patterns were observed for lingual cortical bone thickness or cancellous bone amount across tooth positions within the same age group. With increasing age, the buccal cortical bone thickness at the same tooth position exhibited a gradual thinning pattern. However, no obvious patterns of change with age were found for either the lingual cortical bone thickness or the amount of cancellous bone at the same tooth position. CONCLUSIONS: The remodeling pattern of the mandibular alveolar bone is significantly influenced by both tooth position and age, with the most pronounced effects observed on the buccal cortical bone. CLINICAL RELEVANCE: These findings suggest that clinical practices such as oral implantology and orthodontics should pay particular attention to the status of the buccal cortical bone, especially in the anterior region and in older patients.