Risk factors for reconstruction plate exposure after surgery in oral cancer patients. A retrospective cohort study

Biomechanical evaluation of implant options for unilateral maxillary defects: a finite element analysis

OBJECTIVE

This study aimed to evaluate stress distribution in unilateral maxillary defects using finite element analysis (FEA) to compare subperiosteal (SI) and zygomatic implants (ZI).

MATERIALS AND METHODS

A 3D model of a unilaterally atrophied maxilla was reconstructed from CT scans. Five scenarios were simulated: (1) quad zygoma implants (SC1), (2) zygoma and conventional implants (SC2), (3) two-piece SI and conventional implants (SC3), (4) one-piece SI and conventional implants (SC4) and (5) one-piece SI implant (SC5). Mechanical properties were assigned based on data in the literature; a 450 N force for occlusal loading and a 93 N force for oblique loads were applied.

RESULTS

Under vertical loading, SC2 exhibited the highest tensile stress (Pmax) in the atrophic region (R-AM), while SC4 showed the lowest Pmax across the entire maxilla, indicating better stress distribution. Under oblique forces, SC2 also showed the highest Pmax in R-AM, while SC5 had the lowest Pmax overall. Minimum principal stress (Pmin) followed similar patterns, with SC4 and SC5 demonstrating lower stress levels than the other scenarios. Abutment stresses were highest in SC2 and lowest in SC4. Overall, the SI scenarios (SC3-SC5) exhibited lower stress transmission to the alveolar bone than the ZI scenarios (SC1 and SC2), with SC4 providing the most balanced stress distribution across all regions.

CONCLUSIONS

SI implants, mainly the one-piece SI (SC4), offered a more favourable stress distribution than ZI implants in unilateral maxillary defects, reducing the risk of excessive bone stress. This finding suggests that SI implants may be superior for such cases, although individual patient anatomy should guide implant selection. Further clinical studies are necessary to confirm these biomechanical findings in vivo.

CLINICAL RELEVANCE

This study underscores the crucial role of implant selection in minimising stress on the alveolar bone in unilateral maxillary defects. Based on these findings, we recommend personalised implant strategies based on biomechanical insights to enhance outcomes in maxillofacial reconstruction.

Removable partial prosthesis combined with swallowing training is an efficient clinical solution for oral cancer post-operation patients with palatal defect and dysphagia: a prospective study

OBJECTIVE

Dysphagia is one of the major complications of oral cancer patients, and is disturbing thousands of patients worldwide. Our study aim to evaluate the clinical efficacy of prosthesis combined with swallowing training on palatal defect and dysphagia in post-operative oral cancer patients.

MATERIALS AND METHODS

Sixteen oral cancer patients with palatal defect and dysphagia post-operation were treated with removable prosthesis and individualized swallowing function training. Swallowing function of patients before and after treatment was analyzed and compared by videofluoroscopic swallowing examination. The severity of depression and life quality were evaluated by Depression Scale (SDS) and Functional Assessment of Cancer Therapy-Head and Neck (FACT-H&N) scores, respectively.

RESULTS

Oral transit time (OTT) significantly shortened after treatment (P < 0.01), and Penetration-Aspiration Scale (PAS) scores was significantly higher after treatment (P < 0.001). Different consistency bolus showed different risk of aspiration. Thickened liquids were related to lower PAS scores (P < 0.001). SDS standard score was significantly lower after treatment (P < 0.05). The total score of FACT-H&N after treatment was significantly higher (P < 0.05). No patients came back for regressed swallowing function during the follow-up period (17.06 ± 2.376 months).

CONCLUSION

Removable prosthesis and swallowing training can significantly improve swallowing function, reduce depression degree, and improve quality of life (QOL).

CLINICAL RELEVANCE

Removable prosthesis combined with swallowing training is a cheap and effective method to improve QOL in patients with palate defect and dysphagia after oral cancer.