The impact of immediate versus delayed mini-screw placement on alveolar bone preservation and bone density following tooth extraction: evidence from a canine model.

The aim of this study was to evaluate the impact of mini-screw placement on the alveolar ridge using a split-mouth design. Twelve beagles underwent bilateral extraction of their lateral teeth. In the immediate group, a mini-screw was unilaterally placed approximately 3-4 mm below the alveolar crest of the extraction site on the experimental side. The delayed group received mini-screws six weeks after tooth extraction. On average, the dogs were sacrificed after 11 weeks, and the maxillary bones were excised and scanned using cone-beam computed tomography (CBCT). Histopathological examinations were conducted to assess inflammation and bone formation scores. The results showed that in the immediate group, bone height was significantly greater on the intervention side compared to the control side (p < 0.05), whereas there was no significant difference in the delayed group. In both groups, there was a significant increase in bone density around the mini-screws compared to the control sides (p < 0.05). Mini-screw insertion led to a significant enhancement of bone growth in both groups (p < 0.05), with no notable differences between the two groups. The mini-screws did not have any impact on bone inflammation or width. Overall, both immediate and delayed mini-screw placement in the extraction socket positively influenced bone dimensions, density, and histological properties. However, immediate insertion was more effective than delayed placement in preserving vertical bone height, despite delayed insertion resulting in higher bone density.

Two Cases of COVID-Related Osteonecrosis of the Jaws: A New and Worrying Entity Is Emerging.

Many people were affected by COVID-19 in its severe form. Some intercurrences are still emerging. We here report two cases of COVID-related osteonecrosis of the jaws (CRONJ). Two retrospective cases were admitted into Imam Reza Hospital, Mashhad, Iran with suspected CRONJ. One patient escaped from hospital while the other showed a positive result after our proposed treatment. A new aftermath to COVID-19 infections is emerging. Maxillofacial and orthopedic surgeons should be aware of this situation. CRONJ should be on the suspect list in patients with COVID-19. Measures that are useful in the treatment carried out, as well as some measures recommended in the literature, were discussed. Surgical treatment of CRONJ appears to be an effective alternative, especially in the more aggressive cases.

Efficacy of Platelet-Rich Fibrin Combined with Autogenous Bone Graft in the Quality and Quantity of Maxillary Alveolar Cleft Reconstruction.

INTRODUCTION: The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) on the quality and quantity of bone formation in unilateral maxillary alveolar cleft reconstruction using cone beam computed tomography. MATERIALS AND METHODS: This study was conducted on 10 non-syndromic patients with unilateral cleft lip and palate within the age group of 9-12 years. The study population was randomly assigned into two groups of PRF and control, each of which entailed 5 cases. In the PRF group, the autogenous anterior iliac crest bone graft was used in combination with PRF gel. On the other hand, the control group was subjected to reconstruction only by bone graft. The dental cone beam CT images were obtained immediately (T0) and 3 months (T1) after the operation to assess the quality and quantity of the graft. Independent and paired sample t-tests and analysis of covariance were used to analyze and compare the data related to the height, thickness, and density of the new bone. RESULTS: The mean thickness difference of the graft in both PRF and control groups at T0 and T1 was not significantly different (P>0.05). Furthermore, the reduction changes of bone height at the graft site from T0 to T1 were not statistically significant for both groups (P=0.78). The mean total bone loss of the regenerated bone from T0 to T1 was lower in the control group than that in the PRF group; however, this difference was not statistically significant. CONCLUSION: The usage of PRF exerted no significant effect on the thickness, height, and density of maxillary alveolar graft.