Patient's characteristic included for treatment with individualized allogenic 3D bone block before or during/after orthodontic treatment: A 6-year observational study.

Background: The most important part of orthodontic treatment (OT) is the pre-orthodontic examination (PE). Only a precise evaluation of clinical and radiological features can reduce the risk of complications.

Objectives: To develop practical guidelines for advanced clinical-radiological pre-orthodontic examinations and for qualifying patients for alveolar bone reconstructions.

Material and methods: A retrospective assessment was performed on 49 out of 145 patients (aged 22-55) referred for alveolar bone reconstructions over a 6-year observation period, with 77.6% of the patients being women. Patient examinations were conducted using the following parameters: clinical (e.g., gingival recession (GR), Miller and Angle classifications), radiological (using cone beam computed tomography (CBCT) to evaluate bone dehiscence, occlusal plane (OccP), atlanto-occipital joint position (O-C1), width of mentalis muscle (B:D), bone marrow steatosis (BMS), and various cephalometric parameters such as the position of the alveolar ridge (AR) relative to the mandible, labial width angle, and volumetry of AR, as well as vitamin D level. Statistical analyses were performed using Student's t-test, Shapiro-Wilk test and Pearson's χ2 test.

Results: In the group of patients before orthodontic treatment (OT), the average bone marrow steatosis (BMS) was significantly lower compared to that in patients after treatment (-12 HU vs -137 Hounsfield units (HU)). In patients with class C dehiscence, the B:D measurement was significantly greater than in those with class A dehiscence (15.0 mm vs 12.5 mm). Additionally, a lateral shift of the atlanto-occipital joint (Oc-1) had a significant negative impact on the angles describing lower teeth inclination. Overall, the odds of gingival recession (GR) were 6.5 times higher in women (OR = 6.55); GR odds increased by more than 3.5 times when B:D exceeded 14.1 mm, by 4 times when the occlusal plane (OccP) was flat, and by 8 times when bone density was 24.9 ng/mL.

Conclusions: Insufficient bone volume was observed in a similar proportion both before and during/after orthodontic treatment. The described pre-orthodontic examination allows for an accurate assessment of soft tissue and bone condition, thereby reducing the risk of further complications. CBCT should become a standard component of the pre-orthodontic examination.