BACKGROUND:Bone mass deficiency is common during implantation in the maxil ary posterior region. Some patients do not want to accept extra surgery for increasing bone because of surgical trauma or medical expenses. Technology of the tilted implant has been proposed, but it has not been recognized and has a lack of relevant evidence.
OBJECTIVE:To investigate the stress distribution of per-implant bone which is subjected to different loading conditions when the different abutment angulations are applied, and to analyze the safety factor of different implants to verify the feasibility of the tilted implant in the maxil ary posterior region.
METHODS:The finite element models of the different angulate abutments were established in commercial software packages. The safety factor of implant in the same power load was observed, and stress and strain condition of the implant and the surrounding bone was also observed.
RESULTS AND CONCLUSION:With the increased abutment angulation, the maximum strain of pre-implant bone was significantly increased, and the safety factor of implant decreased gradual y. Thus, the tilted implant is not recommended in the maxil ary posterior region.

With the aging of population, the elderly (≥65 years old) cancer patients have become one of the main populations for cancer care. For inoperable locally advanced head and neck squamous carcinomas, cisplatin-based concurrent chemoradiotherapy is the first-line choice. Several large clinical studies have shown that patients under 70 years of age can still benefit from concurrent chemoradiotherapy, while it should be cautious to apply chemotherapy to patients aged 70-80 years. For elderly patients who are intolerant to cisplatin, carboplatin or other regimens with less gastrointestinal and renal toxicity should be considered. Although anti-epidermal growth factor receptor (EGFR) monoclonal antibodies combined with radiotherapy has been proved to be more effective than radiotherapy alone in total patient population, age-subgroup analysis showed limited benefit in elderly patients. The safety of immune checkpoint inhibitors in elderly patients has been validated and those with high programmed death ligand-1 (PD-L1) expression may benefit from concurrent or neoadjuvant immunotherapy, however, high-level evidence is still lacking. For patients older than 80 years, radiotherapy alone may be superior to concurrent chemoradiotherapy, and hypofractionated radiotherapy for palliative purposes can be safely used in this population.

Radiotherapy is an essential part of comprehensive treatment, as well as a radical treatment for head and neck cancer (HNC). The COVID-19 has continued so far, imposing a great impact on cancer care. Since conventional fractionated radiotherapy (CFRT, 2 Gy/F) requires as long as more than six weeks of treatment time, a huge challenge for epidemic control is created for both hospitals and patients. Hypofractionated radiotherapy (Hypo-RT) may be more suitable than CFRT for patients during pandemic by increasing the fraction size, thus reducing fraction number and treatment duration. Early studies have explored the application of Hypo-RT in HNC in palliative setting, which partially proved its safety and effectiveness. Recently, the efforts have been made in definitive treatment using hypofractionated regimen, as well as its combination with systemic treatment and immunotherapy. Indeed, regarding the pandemic of COVID-19, Hypo-RT has been recommended by several expert consensus in the HNC. In this review, relevant research progress was summarized and clinical implication of Hypo-RT in COVID-19 pandemic era was discussed.

AIM: To analyze the causes of blindness and low vision in patients with visual disability in Yangpu District of Shanghai from 2019 to 2022.METHODS:Cross-sectional study. A total of 1 604 patients who participated in the evaluation of visual disability in Shanghai Yangpu District Kongjiang Hospital, from April 2019 to December 2022 were selected for the study. The grade of visual disability and the main causes of blindness and low vision were determined by trained doctors.RESULTS:A total of 804 patients with visual disabilities were identified, with 87.31% aged 60 and above. The causes of visual disability were high myopic retinopathy(30.47%), age-related macular degeneration(23.26%), glaucoma(17.04%), and diabetic retinopathy(11.07%). Glaucoma(36.96%)is the leading cause of blindness.CONCLUSION: The majority of patients with visual disability are aged 60 years and above. More attention should be paid to the elderly population. Comprehensive prevention, treatment and rehabilitation measures should be applied in different diseases based on classification, so as to early reduce the occurrence of visual disability.