New complementary alternatives in third molar autotransplantation: A systematic review

BACKGROUND

Dental autotransplantation (DAT) is defined as the replacement or direct transfer of an impacted, semi-impacted or erupted tooth to a donor site, either to a post-extraction socket or to a surgically created socket within the same individual. The use of new technological advances, such as 3-D dental models based on computer-aided design, among others, have been reported to improve the success rate of DAT. Therefore, we aimed to perform a systematic review to explore the possible benefits that the use of these innovative techniques can provide when applied to DAT.

MATERIAL AND METHODS

The literature search was conducted in PubMed, Scopus, and Web of Science databases following the PRISMA guidelines. The research question was: "Are computerized technological advancements a useful tool for improving the success of third molar autotransplantation technique?

RESULTS

The initial literature search identified 195 articles, of which only 11 were included for qualitative analysis. All studies used 3D dental models based on computer-aided design data. Surgical guides and stereolithographic models were used by 4 and 1 study respectively. A total of 91 transplanted teeth were evaluated, out of which only 88 were considered within the parameters of clinical success (96.7%). Only 7 out of the 11 articles reported the specific autotransplanted tooth, being mandibular third molars the most prevalent autotransplanted teeth.

CONCLUSIONS

Although the application of new technologies for DAT increases the success rate of this technique, further primary studies are still needed to address long-term teeth survival rates and complications. The cost and availability to implement the integration of these techniques to DAT may be a variable to consider, as this can be a limitation for some patients or for low-income countries.

Perineural invasion predicts poor survival and cervical lymph node metastasis in oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) usually invades peripheral nerves through a process known as perineural invasion (PNI), recognized as an adverse factor considered for the administration of postoperative adjuvant therapy. The aim of this study was to assess the impact of PNI on survival and cervical lymph node metastasis in a cohort of OSCC patients.

MATERIAL AND METHODS

Presence, location and extension of PNI were assessed in a cohort of 57 paraffin-embedded OSCC resections. Clinico-pathological variables were obtained from each case. Five-year overall survival (OS) and 5-year disease-specific survival (DSS) curves were constructed according to the Kaplan-Meier method and compared with log-rank test. The Cox proportional hazard model was used to assess the role of PNI as an independent risk factor related to poor survival, and a binary logistic regression was performed to estimate the predictive value of PNI for regional lymph node metastasis.

RESULTS

PNI was observed in 49.1% of the cases, affecting only small nerves. Peritumoral PNI was the most common location, and multifocal PNI the most frequent extent. Most PNI positive cases had cervical metastasis (p=0.001), and PNI was more frequent in stages III-IV than in I-II (p=0.02). The five-year OS and the 5-year DSS decreased in PNI positive and peritumoral PNI cases. PNI was an independent risk factor for poor 5-year OS and poor 5-year DSS. The odds for cervical lymph node metastasis were of 6.076 (p=0.006) and 10.257 (p=0.007) for PNI and Tumor budding (TB) positive cases, respectively.

CONCLUSIONS

PNI is a frequent finding in OSCC and an independent risk factor for poor OS and DSS. PNI and TB are both risk factors associated to an increased likelihood for the development of lymph node metastasis. Therefore, we suggest further investigations to test the combined PNI-TB scoring system in risk stratification models for OSCC.

Decellularized allografts as an alternative for reconstruction of large inferior alveolar nerve defects: a systematic review

BACKGROUND

Inferior alveolar nerve (IAN) injuries are a clinical problem with devastating consequences, causing temporary or permanent paresthesia, significantly affecting the patient's quality of life. Despite morbidity, side effects and controversy regarding its results, autologous nerve grafting is still the main treatment for these type of lesions. However, due to advances in knowledge about nerve damage and with the aim of preventing the described problems of autografts, new treatment alternatives based on decellularized allografts have emerged. The aim of this systematic review was to evaluate the reported efficacy of decellularized allografts for the treatment of IAN damage.

MATERIAL AND METHODS

We performed a systematic search in Pubmed, Scopus and Web of Science databases following the PRISMA guidelines. Cohort studies, randomized or non-randomized clinical studies, prospective or retrospective studies, without age limits and language restriction that included human subjects who received decellularized allograft as treatment for IAN damage were included.

RESULTS

Six articles met the inclusion criteria and were included for data analysis. In all 6 articles, resolution of IAN damage was observed in more than 85% of patients after a 12-month follow-up period, and in 2 of them, complete resolution was observed in 100% of their patients at longer follow-ups.

CONCLUSIONS

Decellularized allograft appears to be a promising alternative to resolve IAN lesions, without requiring a nerve autograft procedure. However, more randomized clinical trials are needed to validate adequate treatment modalities with decellularized allografts.