Tormod Bjartveit Krüger

• Süslü, Safiyye; Haugen, Håvard Jostein; Krüger, Tormod Bjartveit; Reseland, Janne Elin & Herlofson, Bente Brokstad (2026). Medication-related osteonecrosis of the jaw in cancer and osteoporosis patients: a retrospective seven-year single-center Norwegian cohort study of clinical profiles and documented soft tissue healing. Acta Odontologica Scandinavica. ISSN 0001-6357. 85, p. 713–724. doi: 10.2340/aos.v85.46983. Full text in Research Archive Show summary

  Objective: To compare systemic profiles, oral findings, and documented soft tissue healing between cancer and osteoporosis patients with medication-related osteonecrosis of the jaw (MRONJ). Material and methods: This retrospective single-center cohort included 105 cases treated in 2013–2019 (56 cancer; 49 osteoporosis). Healing at last follow-up was analyzed using adjusted logistic regression and Firth sensitivity analysis. Results: Of 102 cases with known final status, 68 had documented healing. Osteoporosis cases were older, predominantly female, and had longer antiresorptive exposure than cancer cases (76.7 ± 11.1 vs. 70.0 ± 8.5 years; 102.5 ± 77.8 vs. 34.6 ± 28.5 months; both p < 0.001). Stage II predominated and Stage 0 was uncommon (3/105, 2.9%). Previous tooth extraction at the MRONJ lesion site was more frequent in osteoporosis (95.9% vs. 71.4%; p < 0.001). Surgical treatment was associated with higher healing odds (adjusted odds ratio [OR]: 11.12, 95% confidence interval [CI]: 4.12 to 33.35; p < 0.001), whereas cancer indication was associated with lower odds (adjusted OR: 0.23, 95% CI: 0.07 to 0.68; p = 0.011). Conclusions: Systemic profiles differed; oral patterns were similar. Non-random treatment and missing healing dates limit interpretation. Previous tooth extraction was the most frequent antecedent event; its indication and timing were unverified.

• Süslü, Safiyye; Haugen, Håvard Jostein; Krüger, Tormod Bjartveit; Herlofson, Bente Brokstad; Reseland, Janne Elin & Eriksen, Erik Fink (2026). Oral findings and antiresorptive therapy exposure duration in postmenopausal women with osteoporosis: a cross-sectional cohort study. BMC Oral Health. doi: 10.1186/s12903-026-09735-z. Full text in Research Archive Show summary

  Background Oral findings are common among older adults, but it is unclear whether they vary with the duration of antiresorptive therapy (ART) exposure or relate to the severity of osteoporosis in postmenopausal women. Methods In this cross-sectional cohort ( n  = 129), postmenopausal women undergoing osteoporosis assessment/follow-up were stratified by ART exposure duration: no current ART control (G1, n  = 50), short ART (G2, 3–5 years; n  = 39), and long ART (G3, > 5 years; n  = 40). The prespecified primary oral endpoint was any mucosal finding ( oral_mucosal_any ), defined as ≥ 1 prespecified mucosal lesion category at oral examination. The oral_mucosal_any endpoint was analysed by component to distinguish traumatic from non-traumatic mucosal findings. Secondary oral endpoints included tooth and molar counts, periodontal findings, and the number of mucosal lesion categories. Group differences were analysed using age- and BMI-adjusted regression (G1 reference). Secondary analyses compared oral findings across fracture-burden strata and hip BMD/T-score categories and evaluated whether oral variables improved discrimination for hip osteoporosis (total hip T-score ≤ − 2.5) beyond age, BMI, and ART group. Results Mucosal findings were common and non-monotonic across ART groups (G1: 52.0%, G2: 30.8%, G3: 52.5%). Among the 59 participants with any mucosal finding, traumatic changes were present in 43 (72.9%); in a mutually exclusive classification, 38 (64.4%) had traumatic-only findings. In age- and BMI-adjusted models, short ART was associated with lower odds of oral_mucosal_any versus controls (OR 0.38, 95% CI 0.16–0.93; p  = 0.035), whereas long ART did not differ (OR 0.94, 95% CI 0.38–2.33; p  = 0.894). Tooth and molar counts, periodontal burden, and non-traumatic mucosal findings showed no robust graded pattern with ART duration. Oral findings were broadly similar across fracture-burden strata and hip BMD categories. Adding total teeth and oral_mucosal_any increased apparent Area Under the Curve (AUC) for hip osteoporosis from 0.795 to 0.820, but optimism-corrected AUC changed only from 0.736 to 0.741 (corrected ΔAUC = 0.005). Conclusions In this cross-sectional cohort, common oral findings did not show a robust graded duration–response pattern across ART exposure groups and were not consistently associated with fracture burden or hip BMD strata. The broad mucosal endpoint was largely driven by common traumatic findings and should be interpreted as a clinically pragmatic but biologically heterogeneous endpoint. Oral variables added negligible optimism-corrected discrimination beyond age, BMI, and ART group.

• Småland-Reksten, Agnes; Agger, Anne Eriksson; Lian, Aina-Mari; Reseland, Janne Elin & Krüger, Tormod Bjartveit (2026). Bisphosphonate and statin: adverse effects of co-medication on wound healing in in vitro models of periodontal tissues. Acta Odontologica Scandinavica. ISSN 0001-6357. 85, p. 125–133. doi: 10.2340/aos.v85.45585. Full text in Research Archive
• Krüger, Tormod Bjartveit; Syversen, Unni; Herlofson, Bente Brokstad; Lian, Aina-Mari & Reseland, Janne Elin (2022). Targeting a therapeutically relevant concentration of alendronate for in vitro studies on osteoblasts. Acta Odontologica Scandinavica. ISSN 0001-6357. 80(8), p. 619–625. doi: 10.1080/00016357.2022.2072522. Full text in Research Archive Show summary

  Objective Bisphosphonates like alendronate mainly exert their effects on osteoclasts. However, osteoblasts are also affected, but exposed to a much lower concentration in vivo than the osteoclasts. Given that the effects are dose-dependent, the intention of the study was to identify a therapeutically relevant concentration of alendronate for in vitro studies on osteoblasts. Materials and methods Primary human osteoblasts were incubated with alendronate (5, 20 and 100 µM) for 1, 3, 7 and 14 days. Proliferation and viability were assessed, and the effects on cellular growth and function were evaluated by multianalyte profiling of selected proteins in cell culture media using the Luminex 200TM. Results The viability was not affected by any of the dosages. Exposure to 5 µM alendronate had a neutral effect on osteoblast proliferation, and on secretion of osteogenic and inflammatory markers, while enhancing synthesis of a marker of angiogenesis. 20 µM alendronate induced a decline in proliferation and affected angiogenic and osteogenic biomarkers adversely. 100 µM alendronate reduced proliferation dramatically, and this dosage was excluded from further experiments. Conclusion A concentration of 5 µM alendronate exerted effects on human osteoblasts that may translate to those observed in vivo and could therefore be relevant for in vitro studies.

• Kruger, Tormod Bjartveit; Herlofson, Bente Brokstad; Lian, Aina-Mari; Syversen, Unni & Reseland, Janne Elin (2021). Alendronate and omeprazole in combination reduce angiogenic and growth signals from osteoblasts. Bone Reports. 14:100750, p. 1–7. doi: 10.1016/j.bonr.2021.100750. Full text in Research Archive Show summary

  Objective: Due to gastrointestinal side effects of oral bisphosphonates (BPs), proton pump inhibitors (PPIs) are often prescribed. PPIs may enhance the risk of osteonecrosis of the jaw, a rare side effect of BPs. Therefore, the objective of this study was to evaluate the effects of the oral BP alendronate (ALN) and the PPI omeprazole (OME) alone and in combination on primary human osteoblasts and gingival fibroblasts in vitro. Methods: Human gingival fibroblasts and normal human osteoblasts were incubated with either 5 μM of ALN or 1 μM of OME, or ALN + OME for 1, 3, 7 or 14 days. Effect on viability was evaluated by the lactate dehydrogenase activity in the medium and on proliferation by quantifying 3H-thymidin incorporation. Multianalyte profiling of proteins in cell culture media was performed using the Luminex 200TM system to assess the effect on selected bone markers and cytokines. Results: The proliferation of osteoblasts and fibroblasts was reduced upon exposure to ALN + OME. ALN induced an early, temporary rise in markers of inflammation, and OME and ALN + OME promoted a transient decline. An initial increase in IL-13 occurred after exposure to all three options, whereas ALN + OME promoted IL-8 release after 7 days. OME and ALN + OME promoted a transient reduction in vascular endothelial growth factor (VEGF) from osteoblasts, whereas ALN and ALN + OME induced a late rise in VEGF from fibroblasts. Osteoprotegerin release was enhanced by ALN and suppressed by OME and ALN + OME. Conclusions: ALN + OME seemed to exaggerate the negative effects of each drug alone on human osteoblasts and gingival fibroblasts. The anti-proliferative effects, modulation of inflammation and impairment of angiogenesis, may induce unfavorable conditions in periodontal tissue facilitating development of osteonecrosis.

• Kruger, Tormod Bjartveit; Herlofson, Bente Brokstad; Landin, Maria Augusta Dos S Silva & Reseland, Janne Elin (2016). Alendronate alters osteoblast activities. Acta Odontologica Scandinavica. ISSN 0001-6357. 74(7), p. 550–557. doi: 10.1080/00016357.2016.1217041. Full text in Research Archive
• Kruger, Tormod Bjartveit; Sharikabad, Mohammad Nouri & Herlofson, Bente Brokstad (2013). Bisphosphonate-related osteonecrosis of the jaw in four Nordic countries and an indication of under-reporting. Acta Odontologica Scandinavica. ISSN 0001-6357. 71(6), p. 1386–1390. doi: 10.3109/00016357.2013.764007. Full text in Research Archive

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• Wang, Qidi; Akdeniz, Cennet; Heck, Ansgar; Bjørk, Mai Britt; Theisen, Ole Rasmus & Eggesbø, Heidi Beate [Show all 16 contributors for this article] (2025). X-bundet hypofosfatemi. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 145(3). doi: 10.4045/tidsskr.24.0476. Full text in Research Archive Show summary

  X-bundet hypofosfatemi er en sjelden genetisk sykdom som medfører fosfattap i nyrene, redusert mineralisering av tenner og skjelett, deformerte knokler og begrenset mobilitet. Dette har betydelige konsekvenser for helse og livskvalitet. Denne kliniske oversikten gjennomgår anbefalinger for diagnostisering, behandling og oppfølging av voksne med tilstanden.

• Kruger, Tormod Bjartveit; Reseland, Janne Elin & Herlofson, Bente Brokstad (2013). The effect of zoledronic acid on human osteoblasts in vitro. Full text in Research Archive
• Kruger, Tormod Bjartveit & Herlofson, Bente Brokstad (2011). Is there an under-reporting of bisphosphonate-related osteonecrosis of the jaw in the Nordic countries? Full text in Research Archive

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