Florian A. Probst

Background/Objectives: The aim of this study is to examine the relationship between cervical spine and jaw bone mineral density (BMD) and assess how cortical thickness and BMD influence primary implant stability (PIS) across different bone health conditions. Methods: The study included 29 patients (mean age: 63.7 ± 13.7 years; 13 women) and 15 healthy controls (mean age: 25.3 ± 3.0 years; seven women). Cervical spine (C2–C4) and mandibular BMD were evaluated using asynchronous calibration and manual segmentation. Cortical thickness was measured, and primary implant stability was assessed via insertion torque in Newton centimeters (Ncm). Results: Cervical spine BMD was significantly lower in the patient group compared to controls (203.0 ± 51.0 vs. 252.0 ± 21.7 mg/dL, p < 0.0001). No significant correlation was found between mandibular BMD and cervical spine BMD in both groups (patients: ρ = 0.1287; p = 0.506, controls r = −0.1214; p = 0.667). Linear regression analysis revealed that cortical thickness alone, not implant site BMD, significantly influenced PIS (F(2.74) = 5.597, p = 0.005). Conclusions: Asynchronous calibration accurately quantifies cervical and mandibular BMD. Cortical thickness rather than overall bone density emerges as a critical factor in determining implant stability. These findings suggest that clinicians should prioritize cortical thickness assessment when planning dental implant procedures, potentially improving outcomes across diverse patient bone health profiles.

Objectives: To detect and evaluate early signs of apical periodontitis using MRI based on a 3D short-tau-inversion-recovery (STIR) sequence compared to conventional panoramic radiography (OPT) and periapical radiographs in patients with apical periodontitis. Materials and methods: Patients with clinical evidence of periodontal disease were enrolled prospectively and received OPT as well as MRI of the viscerocranium including a 3D-STIR sequence. The MRI sequences were assessed for the occurrence and extent of bone changes associated with apical periodontitis including bone edema, periradicular cysts, and dental granulomas. OPTs and intraoral periapical radiographs, if available, were assessed for corresponding periapical radiolucencies using the periapical index (PAI). Results: In total, 232 teeth of 37 patients (mean age 62±13.9 years, 18 women) were assessed. In 69 cases reactive bone edema was detected on MRI with corresponding radiolucency according to OPT. In 105 cases edema was detected without corresponding radiolucency on OPT. The overall extent of edema measured on MRI was significantly larger compared to the radiolucency on OPT (mean: STIR 2.4±1.4 mm, dental radiograph 1.3±1.2 mm, OPT 0.8±1.1 mm, P=0.01). The overall PAI score was significantly higher on MRI compared to OPT (mean PAI: STIR 1.9±0.7, dental radiograph 1.3±0.5, OPT 1.2±0.7, P=0.02). Conclusion: Early detection and assessment of bone changes of apical periodontitis using MRI was feasible while the extent of bone edema measured on MRI exceeded the radiolucencies measured on OPT. Clinical relevance: In clinical routine, dental MRI might be useful for early detection and assessment of apical periodontitis before irreversible bone loss is detected on conventional panoramic and intraoral periapical radiographs.

Background and Objectives: Antiresorptive drugs are widely used in osteology and oncology. An important adverse effect of these drugs is medication-induced osteonecrosis of the jaw (MRONJ). There is scientific uncertainty about the underlying pathomechanism of MRONJ. A promising theory suspects infectious stimuli and local acidification with adverse effects on osteoclastic activity as crucial steps of MRONJ etiology. Clinical evidence showing a direct association between MRONJ and oral infections, such as periodontitis, without preceding surgical interventions is limited. Large animal models investigating the relationship between periodontitis and MRONJ have not been implemented. It is unclear whether the presence of infectious processes without surgical manipulation can trigger MRONJ. The following research question was formulated: is there a link between chronic oral infectious processes (periodontitis) and the occurrence of MRONJ in the absence of oral surgical procedures? Materials and Methods: A minipig large animal model for bisphosphonate-related ONJ (BRONJ) using 16 Göttingen minipigs divided into 2 groups (intervention/control) was designed and implemented. The intervention group included animals receiving i.v. bisphosphonates (zoledronate, n = 8, 0.05 mg/kg/week: ZOL group). The control group received no antiresorptive drug (n = 8: NON-ZOL group). Periodontitis lesions were induced by established procedures after 3 months of pretreatment (for the maxilla: the creation of an artificial gingival crevice and placement of a periodontal silk suture; for the mandible: the placement of a periodontal silk suture only). The outcomes were evaluated clinically and radiologically for 3 months postoperatively. After euthanasia a detailed histological evaluation was performed. Results: Periodontitis lesions could be induced successfully in all animals (both ZOL and NON-ZOL animals). MRONJ lesions of various stages developed around all periodontitis induction sites in the ZOL animals. The presence of MRONJ and periodontitis was proven clinically, radiologically and histologically. Conclusions: The results of this study provide further evidence that the infectious processes without prior dentoalveolar surgical interventions can trigger MRONJ. Therefore, iatrogenic disruption of the oral mucosa cannot be the decisive step in the pathogenesis of MRONJ.

Transcutaneous submandibular approaches are the preferred technique for the application of load-bearing mandibular osteosynthesis plates. However, an extraoral approach is associated with several shortcomings, like the risk of harming the facial nerve and scarring. This technical note presents a specialized mandibular reconstruction plate (MatrixMANDIBLE Preformed Reconstruction Plate [Synthes Maxillofacial, Paoli, PA]), simplifying the transoral application by its design with a preformed curvature along the lateral surface of the mandible. The application of wide-spanning plates reaching from the posterior margin of the ramus even into the contralateral body region is facilitated. Transoral application of preformed mandibular reconstruction plates seems to be a promising option to bypass external incisions and to reduce operating room time.