Feasibility and accuracy of using intraoral scanners to digitize maxillectomy
defects for prosthetic rehabilitation: A systematic review
Authors:   Department of Maxillofacial
            Prosthetics, Graduate School, Tokyo Medical and Dental University (TMDU), Tokyo,
            Japan., Elbashti Mahmoud , Molinero-Mourelle Pedro ,   Department of Conservative
            Dentistry and Orofacial Prosthodontics, Complutense University of Madrid, Madrid,
            Spain., Aggarwal Himanshi ,   Department of Restorative
            Sciences, University of Alabama at Birmingham, Birmingham, United States., Aswehlee Amel ,   Department of Dental
            Technology, University of Tripoli, Tripoli, Libya., Schimmel Martin ,   Department of Reconstructive
            Dentistry and Gerodontology, University of Bern, Bern, Switzerland., Abou-Ayash Samir ,   Department of Reconstructive
            Dentistry and Gerodontology, University of Bern, Bern, Switzerland., Yamamori Tetsuo ,   Department of Prosthetic
            Dentistry, School of Dentistry, Ohu University, Koriyama, Japan, and Chair of Dental
            Service Problem Committee, Japan Prosthodontic Society（2019-2023)., Baba Kazuyoshi ,   Department of
            Prosthodontics, School of Dentistry, Showa University, Tokyo, Japan, and President of
            Japan Prosthodontic Society（2021-2023)., Sumita Yuka ,   Department of Maxillofacial
            Prosthetics, Graduate School, Tokyo Medical and Dental University (TMDU), Tokyo,
            Japan.
Published: May 2022

Purpose: Few studies have focused on the feasibility and accuracy of intraoral
digital impressions for maxillectomy defects, especially for extensive soft tissue
defects. Using intraoral scanners alone might be feasible for producing maxillary
obturator prostheses, albeit with some limitations. It seems logical to investigate this
ambiguity. Therefore, this systematic review aimed to assessing the feasibility and
accuracy of using intraoral scanners (IOSs) to digitize maxillectomy defects. Materials
and Methods: PubMed, the Cochrane Oral Health Group Trials Register, and the Cochrane
Central Register of Controlled Trials were electronically searched, and five
prosthodontics journals were manually searched for English-language articles published
as of December 2020 that assessed the feasibility and accuracy of using intraoral
scanners to acquire digital impressions for maxillectomy defects. Results: Two in vitro
studies, three clinical studies, six clinical reports, and three techniques were
included (N=14). Aramany’s and Brown’s classifications were used to classify defects in
twelve and one articles, respectively; the remaining article did not specify defect
class. The 3M True definition IOS with Cone-beam computed tomography (CBCT), Computed
tomography (CT), and/or optical scanners were used in both in vitro studies, mainly to
evaluate accuracy. The Trios 3 scanner was used in nine studies as the main resource for
data acquisition (75.0%), whereas the Trophy 3DI, Lava, and Cerec Omnicam scanners were
used in three articles (25.0%). Four degrees of feasibility were identified: feasible
(14.3%), feasible with limitations (28.6%), feasible with CBCT or CT (35.7%), and
feasible with conventional impressions (21.4%). Accuracy was evaluated in four studies
but was not mentioned in ten studies. Conclusion: The results revealed a low level of
evidence for the feasibility and accuracy of using intraoral scanners to digitize
maxillectomy defects. Additional multicenter clinical studies are needed to evaluate the
feasibility and accuracy of digital workflow compared with the conventional
approach.