Labial Bone Volume Nearly Doubled With PAOO in Class III Surgical Cases

Edited by Dentaltown staff

Labial alveolar bone volume in the mandibular anterior region nearly doubled in adults who received periodontally accelerated osteogenic orthodontics during combined orthodontic-orthognathic treatment for skeletal Class III malocclusion, while matched controls showed no labial gain and lost total bone volume, according to a study published Aug. 17 in the American Journal of Orthodontics and Dentofacial Orthopedics.

The study included 42 adults, 21 treated with PAOO and 21 in a matched control group. Cone beam computed tomography was obtained at baseline and after treatment for both groups, with an additional scan six months after PAOO for the treated group. Labial, lingual, and total alveolar bone volumes were quantified using a deep learning-assisted automated segmentation tool, and linear mixed-effects models analyzed longitudinal changes adjusted for baseline root length.

In the PAOO group, labial alveolar bone volume rose from 42.94 cubic millimeters at baseline to 84.15 cubic millimeters after treatment, at P less than .001. Total alveolar bone volume rose alongside it, from 114.20 to 139.92 cubic millimeters, also at P less than .001.

The control group moved the other way. Labial bone volume did not change, at P = .846, and total bone volume fell to 93.76 cubic millimeters, at P less than .001, a decline the authors attribute primarily to loss on the lingual side.

By the end of treatment, the PAOO group had significantly greater labial and total alveolar bone volumes than controls, at P less than .001.

The authors concluded that PAOO was associated with increased and maintained labial alveolar bone volume, which may help preserve total alveolar support during combined treatment, and that deep learning-assisted CBCT segmentation can serve as an efficient volumetric evaluation tool.

Mengqiao Pan, Runzhi Guo, Huifang Yang, Jian Liu, Li Xu, and Jianxia Hou conducted the study at Peking University School and Hospital of Stomatology. It was funded by the Beijing Natural Science Foundation.

Patients were not randomly assigned, so surgical candidacy, periodontal phenotype, and clinician judgment may have influenced both who received PAOO and the outcome. The volumes were measured to the end of treatment, so the durability of the labial gain remains open.

Sources:
American Journal of Orthodontics and Dentofacial Orthopedics, “Deep learning-assisted cone-beam computed tomography volumetric assessment of mandibular anterior alveolar bone changes with and without periodontally accelerated osteogenic orthodontics during skeletal Class III orthodontic-orthognathic treatment,” published online Aug. 17, 2026: sciencedirect.com/science/article/pii/S0889540626003379
DOI: doi.org/10.1016/j.ajodo.2026.06.012
PubMed, PMID 42606395: pubmed.ncbi.nlm.nih.gov/42606395