Finite element stress analysis of Aramany class I maxillectomy defect with single‐ and two‐piece closed bulb obturators

Abstract

Restoration of acquired maxillary defect with an obturator prosthesis is a well evident approach in rehabilitation of maxillofacial defects. 1 Obturator therapy enhances the phonetics, aesthetics, swallowing and mastication, and occludes the oral and nasal cavity, thereby escalating the quality of life of patients. 2 Intraoral scenario of a maxillectomy state is much incomparable to that of a normal partial edentulous situation. 3 The prosthesis has to depend principally on the remaining hard and soft tissues for retention, stability and support. Nevertheless, a heterogeneous pattern of force gets transmitted when the patient performs any oral function. Altogether, more dislodging and rotational force get activated when the defect is huge and normal residual structures are less. 4,5 The size and configuration of the maxillectomy defect is one of the significant factors determining the prognosis of treatment.Lightweight hollow prostheses are fabricated when the defect size is large in order to improve the retention, stability, speech resonance and comfort of the patients. 6 A definitive closed hollow bulb obturator is the preferred mode of therapy proximately 6 months after

Biomechanical Stress in Obturator Prostheses: A Systematic Review of Finite Element Studies

“…One of them evaluated the stress in congenitally unilateral palatal cleft scenario [25], one used mainly in vivo approach with no interpretation in the result and discussion sections regarding FEA [23], and four different studies were duplicated in their methodology and results [24,26], so we chose the earlier studies [13,27]. Finally, 13 articles were recruited for this review [13,[27][28][29][30][31][32][33][34][35][36][37][38]. The number of primary surveyed articles, number of excluded articles, reasons for exclusion, and the final recruited articles are shown in Figure 1.…”

“…The use of Vertex polymer as a retainer with an occlusal plate on the main abutment teeth was found to reduce stress on the teeth without compromising the stability of the prosthesis [24]. There were no significant differences in the distribution of stress between the single-and two-piece hollow obturators, although the two-piece obturator showed a slight lower stress value than the single-piece obturator [29,36].…”

“…Exclusion criteria (1) The studies conducted between January 2010 and December 2020 (2) Studies conducted in the English language (3) In vitro mathematical studies (4) Studies conducted only on partial and complete removable maxillofacial obturators (5) The case with surgical maxillary defect (6) Studies used only FE methods to predict the distribution of the stress and displacement in MFP 3 BioMed Research International that assessed the differences in displacement between singleand two-piece closed hollow-bulb obturators [29]. In the reviewed studies, the stress was estimated in the prostheses for partially edentulous scenarios [13,27,29,30,32,[34][35][36][37], while in another it was examined in completely edentulous scenarios [25,28,31,33,38]. Six of the 13 studies reviewed in the current review, examined the influences of implant/s on the distribution of stress in the prostheses.…”

“…The stress distribution of single-piece hollow bulb section was examined by two studies [13,25], while the two-piece was examined by two other studies as well [29,36], and this mostly was to simulate the real situation.…”

“…The main reason for this is owing to the variety of the occlusal forces that can be found in the population, which are dependent on gender, age, general health, natural dentition, and anterior or posterior teeth. However, the mean maximum force 120-150 N were selected, either individually or collectively, in most of the reviewed studies, as it considers the mean maximum force for patients with remaining natural teeth and wearing removable obturator prostheses [13,29,30,32,35,36].…”