Comparison of weight reduction in different designs of solid and hollow obturator prostheses

Influence of different designs of bulb support structures on the accuracy and weight of 3D printed maxillary obturators. An in vitro study

STATEMENT OF PROBLEM

Evidence is lacking on the influence of different designs of bulb support structures on the accuracy of 3-dimensional (3D) printed obturators.

PURPOSE

The purpose of this in vitro study was to evaluate the influence of various infill designs (hollow, honeycomb, and gyroid) for the bulb of an obturator on the accuracy and weight of digital light projection (DLP) 3D printed maxillary obturators.

MATERIAL AND METHODS

A maxillary obturator was virtually designed and used to obtain 3 digital reference files which were defined based on the design of the infill support structure within the bulb: hollow, honeycomb, and gyroid. The resultant standard tessellation language (STL) files were used to fabricate the obturators using a DLP 3D-printer in FREEPRINT denture resin material (n=10 per each group design). The fitting surfaces of all printed specimens (n=30) were digitized using a laboratory scanner, and the scan STL files were exported to the Geomagic control X program for dimensional accuracy analysis (trueness and precision) using the digital subtraction technique. One-way analysis of variance (ANOVA) was used for analysis (α=.05) RESULTS: Quantitative analysis revealed no significant difference in root mean square estimate (RMSE) values among the test groups for trueness (P=.326) and precision (P=.140). Hollow bulb design was significantly lighter in weight than both honeycomb and gyroid infill designs (P<.001). Colormaps revealed increased areas of negative deviation around the circumference of the bulb wall in the hollow design compared with both the gyroid and honeycomb groups and the close surface matching of fitting surfaces in the 3 groups.

CONCLUSIONS

The lack of significant difference in accuracy among the tested groups and the significantly lighter hollow design obturator compared with honeycomb and gyroid designs favors the selection of the hollow bulb design in the digital fabrication of maxillary obturators.

A fully digital approach to replacing an obturator prosthesis using a 3D printed closed hollow bulb: Α dental technique

The replacement of an obturator prosthesis using conventional methods has multiple issues. Standard tessellation language files generated from the superimposition of an accurate intraoral scanning of the maxillary defect and direct data acquisition of the existing hollow bulb obturator can facilitate the precise design of the prosthesis, requiring only minor adjustments. Rapid prototyping manufacturing techniques seem to ensure precise control of the integrity of the prosthetic component completion. The success of the technique is the simplicity and repeatability of designing and fabricating a retrievable and easily repairable obturator.

Interdisciplinary prosthetic rehabilitation following bilateral maxillectomy with total upper lip and unilateral zygoma resection: A clinical report

This clinical report describes the design and fabrication of an implant-retained and soft-tissue-supported obturator prosthesis and a magnetic retained midfacial prosthesis for a patient with a midfacial defect following bilateral total maxillectomy, removal of the left zygoma, and excision of the entire upper lip. The patient underwent multiple head and neck surgeries for 4 separate primary oral cancers, 1 recurrence, and 1 pulmonary metastasis. The definitive obturator prosthesis was retained by 1 zygomatic implant with soft-tissue support and retention. The midfacial prosthesis was attached to the obturator prosthesis with magnets, improving appearance and the recovery of significant aspects of the patient's speech and swallowing. Some improvement in mastication was observed.

A digital and cast-free workflow for fabricating a definitive hollow obturator prosthesis for a maxillectomy defect: A dental technique

This article presents a novel digital and cast-free workflow for fabricating a definitive hollow obturator prosthesis. A digital altered cast is made after the framework-fitting appointment to maximize support. The framework, hollow obturator base, and teeth are digitally designed, additively manufactured, and then assembled precisely without a cast. This method simplifies the laboratory process, reduces human errors, and provides a prosthesis with high accuracy and good fit.

An integrated hollow bulb obturator prosthesis with a metal framework for a soft palate defect fabricated by multiple digital techniques

The digital workflow to fabricate an integrated hollow bulb obturator prosthesis with a metal framework for a patient with soft palate defect is described. The framework was digitally designed with an open lattice denture base connector to facilitate the assembly of the hollow bulb obturator and printed with titanium. A functional impression of the palatopharyngeal area was made, and an integrated 3-dimensional (3D) cast was obtained by aligning the data of the functional impression to the preliminary intraoral scan data. The hollow bulb obturator and a palatal cover were designed based on the integrated 3D cast and the framework design data and printed with light-polymerizing denture base resin. The printed framework, obturator, and palatal cover were assembled and bonded without a physical cast, and the definitive prosthesis exhibited good fit, retention, and stability.

Comparison of the weight of conventionally heat-processed hollow and solid obturators and 3D printed hollow obturators

STATEMENT OF PROBLEM

The weight of larger obturators places increased stress on the supportive teeth and bearing tissue and allows gravity to act as a dislodging factor affecting the stability and retention of the prosthesis. However, whether conventionally processed and 3-dimensionally (3D) printed hollow obturators have similar reduced weights compared with solid obturators is unclear.

PURPOSE

The purpose of this in vitro study was to evaluate the weight difference between conventionally heat-processed complete denture obturators with and without hollowing and 3D printed obturators with a hollow bulb.

MATERIAL AND METHODS

Obturators were fabricated as conventionally heat-processed solid obturators, conventionally heat-processed with a hollow obturator bulb, and 3D printed with a hollow obturator bulb. Nine obturator prostheses were fabricated for each type of Aramany Class I, Class II, and Class III defect. The weights of each of the 27 obturator prostheses were measured, and a statistical analysis was performed with exact versions of the Kruskal-Wallis test or Wilcoxon Rank Sum test (α=.05).

RESULTS

Conventionally heat-processed solid obturators were significantly heavier than the conventionally heat-processed hollow (P<.001) or the 3D printed hollow obturators (P<.001). No significant difference (P=.222) was found between the conventionally heat-processed hollow and 3D printed hollow obturators. The decrease in weight was proportional to the size of the defect with the Aramany Class I defect having the largest differences in weight between the different fabrication methods, followed by Class II, and then Class III with a much smaller defect.

CONCLUSIONS

Additive manufacturing could be a suitable alternative to conventional techniques for the fabrication of a closed hollow obturator because of the comparable weights.

Patient Satisfaction regarding Conventional One-Piece Versus Two-Piece Magnet-Retained Obturator for Patients with Complete Edentulism: A Preliminary Crossover Clinical Trial

Purpose:

This study aimed at evaluating patients' satisfaction with conventional one-piece obturators versus two-piece magnet-retained obturators in completely edentulous patient maxillectomy cases.

Materials and Methods:

Ten completely edentulous participants with hemimaxillectomy (8 males and 2 females) were selected in a crossover study. Participants received a conventional obturator one-piece and two-piece obturators connected by magnet attachment in alternate periods (sequences A‐B and B‐A), and outcomes were assessed after 1 week, 3 months, and 6 months Evaluation was made using Obturator Functioning Scale (OFS) and Oral Health Impact Profile for edentulous people (OHIP-EDENT). One way ANOVA test and multivariate analysis of variance with a general linear model with repeated measures was used to test the impact of the group, time, and order on each of the studied scores (α=.05).

Results:

Magnet design showed a statistically significant lower score (P <.050) than the conventional design regarding the overall satisfaction score of OFS along all follow-up periods. Concerning OHIP-EDENT, the magnet design showed a statistically significant lower score (P <.050) than the conventional design regarding total functional limitations, total physical pain, and total social disability along all follow-up periods while for total psychological discomfort, total physical disability, and total handicap, no statistically significant difference was observed between both groups (P >.050).

Conclusion:

Two-pieces magnet-retained obturator could provide better satisfaction and better restoration of orofacial function than the conventional one to manage completely edentulous patients.

Clinical Trial Registration Number:

NCT05066828

CAD-CAM Hollow Obturator Prosthesis: A Technical Report

An obturator with a hollow bulb can decrease the overall weight of the prosthesis, stress on the underlying tissues, and patient discomfort. Although many techniques and materials have been proposed in the literature for hollowing the obturator prosthesis, they are often time consuming and technique sensitive. This proposed technique used an open‐source software program to hollow a digital design of a solid obturator base from a commercially available software in one single convenient step. The hollowing process allowed precise control of prosthesis thickness at the hollow space area for desirable hermetic seal and prosthesis strength.

Digital workflow and virtual validation of a 3D-printed definitive hollow obturator for a large palatal defect

This clinical report describes how a hollow obturator prosthesis was designed and fabricated for an 82-year-old partially edentulous patient with a large palatal defect. Computer-aided design (CAD) was used to design, articulate, and align the mandibular denture with the obturator prosthesis. The prosthesis was printed, adjusted chairside, rescanned, and made hollow by using a CAD software program. The prosthesis was printed in resin with a dental 3D printer. Quantitative evaluations of clinical (prosthesis dimensions, rest, and occlusal vertical dimensions) and virtual (surface area, volume, weight, interpoint mismatches, spatial overlap) parameters found that the 3D-printed prosthesis required an additional 5% chairside modification. The greatest differences in volume (24.7% less) and weight (22.2% less) were observed when the modified obturator bulb was made hollow via CAD. Hollowing the bulb, therefore, reduced the spatial overlap in volume by 16.8%.

Maxillary hollow-bulb obturator: A paradigm shift

Maxillary defects, whether congenital or acquired, make a patient encounter an array of physical and psychological difficulties, leading to an extremely poor quality of life. Rehabilitation of such a patient is often challenging due to the extent of the defect area coupled with the absence of adequate retention caused by the size and weight of the prosthesis. Further, providing a proper seal of the oronasal communication is of utmost importance to restore function. Taking the above factors into consideration, a combination of hollow-bulb obturator consisting of a titanium framework and a flexible, snap-on silicone cap is an effective prosthesis providing a long-term treatment, increased retention, and a happy patient. The fabrication protocol included the use of computer-aided design, titanium along with laser welding, and an intraoral trial before final fabrication, hence, reconfirming the success of the prosthetic design. The maxillary obturator presented in this article eliminates several disadvantages associated with a conventional hollow-bulb obturator, thereby providing a novel, viable option for a maxillofacial prosthodontist.

Prosthodontic rehabilitation of a sub-total maxillectomy defect with a definitive hollow obturator prosthesis using the modified lost-wax concept: A novel technique

Squamous cell carcinoma (SCC) of the oral cavity is relatively common in the Indian subcontinent with surgical resection and adjuvant radiotherapy/chemotherapy being the treatment modality of choice. Prosthetic rehabilitation with an obturator following resection is more economical and yields satisfactory results. Better patient acceptance and comfort necessitates hollowing the prosthesis to a great extent. This novel method modifies the existing lost-wax technique in fabricating a definitive hollow maxillary obturator. An elderly man had reported to the Department of Prosthodontics with the chief complaint of a “big hole” in the mouth which affected his quality of life. He had undergone subtotal maxillectomy, following a histopathologic diagnosis of SCC, with adjuvant radiotherapy. Examination revealed an Aramany Class II defect with the healthy oral mucosa. A lightweight definitive obturator was designed and fabricated using a simple technique which utilizes easily available modeling wax. This article describes a relatively simple, single-step fabrication of a closed hollow-bulb obturator prosthesis with a uniform thickness of heat-cured resin encapsulating the hollow prosthesis.

Shark Fin Titanium Hollow Bulb Obturator: A Treatment Concept

Restoring esthetics and function for patients with maxillectomy defects presents a complex challenge for the clinician. Obturator prostheses are subject to rotational forces during function, allowing movement into the defect. Gaining prosthesis support from endosseous implants can limit the amount of rotation. Xerostomia and impaired tissue healing caused by radiation therapy further complicates the treatment for such patients. Several resilient and rigid obturator design concepts are available for restoration of such defects. This clinical report describes a design concept used to treat a patient with a maxillectomy defect caused by tumor resection secondary to a squamous cell carcinoma.

Evaluation of water absorption properties and fabrication of hollow obturator model using 3D digital dentistry

Fluid accumulation in the hollow spaces of obturator is a continuing problem when fabricating hollow obturator prostheses using the conventional method. To address this problem, the three-dimensional (3D) digital technology was used to evaluate water absorption in the inner hollow obturator spaces. Solid and hollow obturator specimens were fabricated using a 3D printer with photocurable resin. Then, the hermeticity was examined by leak testing. These specimens were immersed in distilled water at 37°C. Each specimen was weighed every 24 h for 120 days, and weight changes between each group were compared. Water accumulation in the hollow obturator was not visually observed. Although water absorption was significantly higher in solid specimens, the weight increase rate was also significantly higher in hollow specimens. Applying a laminating 3D photo fabrication made the fabrication of a completely unified hollow obturator model possible.

The Effect of Immediate Obturator Reconstruction after Radical Maxillary Resections on Speech and other Functions

Objective: Maxillectomy often results in a high level of morbidity with significant psychological and functional implications for patients. The aims of the present study were to assess the effectiveness of the maxillary obturator as a speech rehabilitation aid, to examine the influence of dentition on speech intelligibility, to restore patients’ regular daily activity as soon as possible, and to maintain patients’ psychological well-being throughout the treatment. Patients and Methods: Forty-one palatomaxillary immediate obturator and definitive reconstruction patient treatments were reviewed at a clinic (Ankara, Turkey). Patients aged between 20 and 73 years with surgically acquired partial maxillary defects were included in this study. All patients were rehabilitated with immediate and definitive obturators. The patients were given immediate surgical obturators which were adjusted to the defect area with a tissue conditioner. By employing this procedure and relining with the tissue conditioner weekly, immediate obturators were used in the interim stage of the treatment. As interim obturators, prostheses were used for two to three months until healing and resorption were found satisfactory, after which the definitive obturators were fabricated. Results: The speech intelligibility test (SIT) was employed for the evaluation of the speech ability. Significant improvements were found in the mean speech intelligibility test score (SITS), from 0.02% in patients without prosthetic obturation to 94.10% in patients with immediate obturation on the second day, 95.60% in patients with immediate obturation on the 20th day, and 95.97% in patients with definitive obturation.

Rehabilitation of hemi-maxillectomy with a definite one piece hollow bulb obturator

Maxillary intraoral defects due to surgical resection create an open link between the oral and nasal cavities causing difficulty in deglutition, speech, and an unaesthetic appearance. Prosthetic innervention is required to restore the needs of speech, mastication as well as closing the oroantral communication. This article shows a case report of systematic approach for fabrication of immediate plate just after surgery, followed by interim feeding plate 2 weeks after surgery, and finally definitive one piece hollow bulb obturator 6 months after surgery.

Hollow Bulb One Piece Maxillary Definitive Obturator - A Simplified Approach

In maxillary defects, role of a prosthodontist is to rehabilitate the intra- and extra-oral structures and to endow with the normal function of mastication, speech, deglutition, and esthetics. Malignancies are common in the oral region and are treated usually through surgical intervention. Surgical intervention creates anatomical defects creating communication between oral and nasal cavity. Patients pose difficulties while performing normal functions such as swallowing and speaking, due to this communication. To overcome the problems encountered by the patient, obturators are fabricated. The main problem with rehabilitation of large defect is the weight of prosthesis; the prosthesis becomes very bulky and nonretentive due to its weight. Hollow obturators are fabricated to conquer this tribulation by different techniques. This case report describes a simplified method of fabrication of a definitive hollow bulb obturator for rehabilitation of a maxillary defect (Aramany's class I) by insertion of balloon.

Lost wax-bolus technique to process closed hollow obturator with uniform wall thickness using single flasking procedure

INTRODUCTION

Maxillary obturator prosthesis is more frequent treatment modality than surgical reconstruction for maxillectomy in patients suffering from oral cancer. The obturators often become heavy and hence are hollowed out in the defect portion to reduce its weight as a standard practice.

MATERIALS AND METHODS

The processing technique described the incorporation of the preshaped "wax-bolus" during packing procedure of the Obturtor prosthesis and eliminated later by melting it once the curing procedure is completed.

RESULTS

This article is a single step procedure resulting into the closed-hollow obturator as single unit with uniform wall thickness around the hollow space ensuring the least possible weight of the hollow obturator.

CONCLUSION

This processing technique achieves predictable internal dimension of the hollow space providing uniform wall thickness of the obturator.

Sealing maxillary titanium obturators with removable flexible caps

Maxillary obturator prostheses with hollow metal obturators can be made of titanium to reduce weight. To prevent perforation of the hollow obturator during modifications, the obturator is slightly undersized and covered with a replaceable cap. This cap is made of a soft copolymer to facilitate uncomplicated modifications in the resection area and to improve function.

Fabrication of Closed Hollow Bulb Obturator Using Thermoplastic Resin Material

Purpose. Closed hollow bulb obturators are used for the rehabilitation of postmaxillectomy patients. However, the time consuming process, complexity of fabrication, water leakage, and discoloration are notable disadvantages of this technique. This paper describes a clinical report of fabricating closed hollow bulb obturator using a single flask and one time processing method for an acquired maxillary defect. Hard thermoplastic resin sheet has been used for the fabrication of hollow bulb part of the obturator. Method. After fabrication of master cast conventionally, bulb and lid part of the defect were formed separately and joined by autopolymerizing acrylic resin to form one sized smaller hollow body. During packing procedure, the defect area was loaded with heat polymerizing acrylic resin and then previously fabricated smaller hollow body was adapted over it. The whole area was then loaded with heat cure acrylic. Further processes were carried out conventionally. Conclusion. This technique uses single flask which reduces laboratory time and makes the procedure simple. The thickness of hollow bulb can be controlled and light weight closed hollow bulb prosthesis can be fabricated. It also minimizes the disadvantages of closed hollow bulb obturator such as water leakage, bacterial infection, and discoloration.

Fabrication of a definitive obturator from a 3D cast with a chairside digital scanner for a patient with severe gag reflex: a clinical report

Patient gagging is a common problem during dental procedures such as maxillary impression making. This clinical report describes the use of a chairside intraoral scanner for a patient with a hypersensitive gag reflex. The technique proved to be a more comfortable alternative for the patient and an accurate method for the clinician to capture both hard and soft tissue detail for the fabrication of a definitive obturator.

Rehabilitation of post surgical maxillectomy defects using interim obturators-a case series

Prosthetic rehabilitation of extensive maxillectomy defects are exigent given the difficulties faced due to loss of palatal bone,teeth and surrounding supporting tissues which help in retention, support and stability of the prosthesis. An interim maxillary obturator is a prosthesis which is made after surgical resection of a portion or all of one or both maxilla where initial healing is completed. Frequently many or all teeth in the defect area are replaced by this prosthesis. It plays a vital role in preventing the facial disfigurement and irritation to the surgical site thereby enhancing the healing and restores the functional capabilities such as speech, mastication, deglutition etc. To gain better retention and stability, preservation of the unaffected regions is needed which can be achieved by proper surgical planning and designing of the prosthesis. This case series describes rehabilitation of three extensive maxillectomy defects with hollow open and closed interim obturators.

Use of polyetheretherketone in the fabrication of a maxillary obturator prosthesis: a clinical report

To treat a patient who needed a replacement for a maxillary obturator prosthesis, a new obturator prosthesis was fabricated from polyetheretherketone (PEEK), a material often used in medicine but seldom in dentistry. This material provided the patient with a better-adjusted, more functional, and lighter prosthesis.

Effect of varying bulb height on articulation and nasalance in maxillectomy patients with hollow bulb obturator

PURPOSE

To evaluate the effect of bulb height of hollow bulb obturator prosthesis on articulation and nasalance.

METHOD

A total of 10 patients, who were to undergo maxillectomy falling under Aramany class-I and II, with normal speech and hearing pattern were selected for the study. They were provided 2 maxillary obturators, one extending full height of the defect and other with bulb height approximately up to inferior nasal concha. The patients were asked to wear each obturator for 6 weeks and the speech analysis was done to measure changes in articulation and nasalance at 6 different stages of treatment i.e. preoperative, postoperative (after complete healing), 24h and 6 weeks after providing full bulb height obturator and reduced bulb height obturator. Articulation was measured objectively for distortion, addition, substitution and omission by speech pathologist and nasalance was measured by Dr. SPEECH software.

RESULT

Comparison between full and reduced bulb height for nasalance and articulation, showed that there was no statistical significant difference (P>0.05) between the two for both the parametres.

CONCLUSION

Articulation and nasality improves after providing obturator. Articulation and nasalance both are independent of bulb height.

Maxillofacial prosthodontic management of an ablative maxillary surgical defect using a combination of conventional obturator prosthesis and an early loading implant supported high-strength full ceramic fixed dental prosthesis

Prosthodontic rehabilitation of maxillary defects and early loading of endosseous implants has been widely published. The combination of the aforementioned treatment modalities are seldom reported in peer reviewed journals. This article describes the clinical presentation, management and prosthodontic rehabilitation of the maxillary defect of a patient. Clinical and scientific concerns are discussed.

Closed hollow bulb obturator--one-step fabrication: a clinical report

A method is described for the fabrication of a closed hollow bulb obturator prosthesis using a hard thermoforming splint material and heat-cured acrylic resin. The technique allowed the thickness of the thermoformed bulb to be optimized for weight reduction, while the autopolymerized seal area was covered in heat-cured acrylic resin, thus eliminating potential leakage and discoloration. This technique permits the obturator prosthesis to be processed to completion from the wax trial denture without additional laboratory investing, flasking, and processing.

Light is Right—Various Techniques to Fabricate Hollow Obturators

Management of malignancies and abnormal growths in maxillary sinus often include ablative surgeries. The closure of the resulting anatomical defect can be achieved with an obturator prosthesis. Reduction in weight of the obturator is an important consideration in improving the retention and stability of the prosthesis. Hollowing the bulb of the obturator (extension of the prosthesis into the defect) is an effective method of reducing the weight of the prosthesis. Such obturators can be one piece or two pieces. Of the many methods to make an obturator hollow, four techniques are described here. Along with the pros and cons of each, the method of fabrication is detailed as well. It is the discretion of the operator to apply these techniques aptly for fabrication of either an interim or a definitive prosthesis.

Speech rehabilitation of maxillectomy patients with hollow bulb obturator

Aim:

To evaluate the effect of hollow bulb obturator prosthesis on articulation and nasalance in maxillectomy patients.

Materials and Methods:

A total of 10 patients, who were to undergo maxillectomy, falling under Aramany classes I and II, with normal speech and hearing pattern were selected for the study. They were provided with definitive maxillary obturators after complete healing of the defect. The patients were asked to wear the obturator for six weeks and speech analysis was done to measure changes in articulation and nasalance at four different stages of treatment, namely, preoperative, postoperative (after complete healing, that is, 3-4 months after surgery), after 24 hours, and after six weeks of providing the obturators. Articulation was measured objectively for distortion, addition, substitution, and omission by a speech pathologist, and nasalance was measured by Dr. Speech software.

Results:

The statistical comparison of preoperative and six weeks post rehabilitation levels showed insignificance in articulation and nasalance. Comparison of post surgery complete healing with six weeks after rehabilitation showed significant differences in both nasalance and articulation.

Conclusion:

Providing an obturator improves the speech closer to presurgical levels of articulation and there is improvement in nasality also.

A hollow definitive obturator fabrication technique for management of partial maxillectomy

Maxillary obturator prosthesis is the most frequent treatment option for management of partial or total maxillectomy. Heavy weight of the obturators is often a dislocating factor. Hollowing the prosthesis to reduce its weight is the well established fact. The alternate technique to hollow-out the prosthesis has been described in this article which is a variation of previously described processing techniques. A pre-shaped wax-bolus was incorporated inside the flasks during packing of the heat-polymerized acrylic resin to automatically create the hollow space. The processing technique described is a single step flasking procedure to construct a closed-hollow-obturator prosthesis as a single unit. To best understand the technique, this article describes management of a patient who had undergone partial maxillectomy secondary to squamous cell carcinoma rehabilitated with a hollow-obturator prosthesis.

Difference in water accumulation patterns between solid and closed hollow obturators under a thermal cycle

Water accumulation in the hollow space of a maxillary obturator is a continuing problem, and it is unclear whether the porosity of acrylic resin is involved in the mechanism. The purposes of the study were to evaluate the effect of a hollow space in the resin obturator on water sorption under a thermal cycle and to determine factors associated with water accumulation in the obturator. Twenty solid spheres (30-mm diameter) and 40 hemispheres (30-mm diameter, 1.5 mm thickness) were fabricated from heat-polymerized acrylic resin. Closed hollow specimens consisted of 2 hemispheres joined with autopolymerizing resin. Ten solid and 10 closed hollow specimens were immersed in distilled water, whereas the other specimens were stored at 100% relative humidity. Each specimen was thermocycled (5°C-37°C) with a dwell time of 12 hours and weighed every 12 hours for 180 days. Of the 20 closed hollow specimens, 16 showed no water accumulation (8 in distilled water, 8 at 100% humidity). The weight of these specimens became saturated by day 90, with increases from the initial weight of 1.41% at 5°C and 1.36% at 37°C. By day 180, the weights of the solid specimens had increased by 0.96% at 5°C and 0.94% at 37°C. Weight fluctuation associated with temperature was observed for both types of specimens and for all storage conditions. It is concluded that water accumulation inside a closed hollow obturator is not directly related to the water absorption properties of the acrylic resin but is related to thermal damage of the obturator.

Inflatable hollow obturator prostheses for patients undergoing an extensive maxillectomy: a case report

The presence of a large palatal or maxillary defect after partial or total maxillectomy for tumor, trauma or congenital deformation poses a challenge to prosthodontists, particularly when the use of an implant cannot be considered. This case report described the use of an air valve in a hollow silicone obturator to manufacture an inflatable obturator that could be extended further into undercut area to retain itself. The inflatable obturator exhibited adequate retention, stability and border sealing, thereby improving the masticatory, pronunciation and swallowing functions of patients. It may be a suitable alternative treatment option to an implant-retained obturator.

Fabrication of a hollow obturator as a single unit for management of bilateral subtotal maxillectomy

Prosthetic rehabilitation with an obturator for a total or subtotal maxillectomy patient is a challenging task, as there are little or no residual maxillary structures to depend on for support, retention, and stability of the prosthesis. This clinical report describes the prosthodontic management of a patient operated on for a bilateral subtotal maxillectomy secondary to ameloblastoma of the palate with a closed hollow obturator. The processing technique described in this article to fabricate the hollow obturator is a variation of other well-known techniques. The variation comprises the use of a wax bolus to maintain a predictable internal dimension for a hollow obturator. This technique allows fabrication of a complete hollow obturator prosthesis as a single unit in heat-polymerized acrylic resin using a single-step flasking procedure.

Prosthetic treatments for patients with oronasal communication

The prosthetic treatments play a role in the rehabilitation of patients with congenital and acquired cleft palate. To prepare the surgical field and/or correct inevitable sequelae of the surgery, the rehabilitation with obturator prosthesis is an auxiliary or complementary treatment to surgical treatments. In cases where the surgical treatment is contraindicated, the prosthetic rehabilitation becomes a definitive treatment. The denture is planned and fabricated according to each patient. Therefore, the aim of this study was to discuss the prosthetic rehabilitation performed in patients with oronasal communication.

Upper lip prosthesis retained to a palatal obturator

In cases of total or partial maxillectomies, the prosthetic rehabilitation is an effective alternative to minimize the sequelae left by surgical resection. The present study reports a clinical case of a 52-year-old patient who underwent partial maxillectomy, with upper lip involvement. The oronasal communication, resultant from surgical resection, did not allow the patient to return to her normal social life. Besides, the upper lip partial resection damaged her face's aesthetics. The proposed treatment was the confection of an upper lip prosthesis retained by a palatal obturator. The prosthesis insertion restored the patient's facial aesthetics, contributing not only to function, but also to psychosocial adaptation.

Prosthetic rehabilitation of Oro-nasal defect

Maxillofacial defects may be due to congenital defect, trauma, tumor or infection. Among infections, fungal head and neck infections are common complication in patients with immunological or metabolic compromise. Cerebral extension of these infections often complicates the treatment plan. Treating these cases requires correction of the compromised state, local and systemic anti-fungal therapy and repeated radical debridement assisted by serial imaging. Following debridement, the resultant deformity can be corrected either surgically or prosthetically. Many factors are to be considered regarding the choice of the treatment. Here is a case report of a 55 year old male diabetic patient with oro-nasal mycosis, where debridement resulted in a gross morbid defect of the dorsum of the nose and the hard palate. Prosthetic rehabilitation was carried out with separate nasal prosthesis and a palatal feeding obturator.

Rehabilitation of a congenital palatal defect with a modified technique: a case report

Introduction

Constuction of the obturator prostheses and providing the patient's comfort with them are very difficult. Primary and the most important stage for these prostheses is to perform a proper impression.

Case Presentation

A 55-year-old edentulous Turkish female patient with a congenitally maxillary defect was rehabilitated with an open hollow obturator prosthesis. After the preliminary impression was completed, a metal frame suitable with the maxillary defect was constructed manually and used for making the impression of the defect area. After the first part of the obturator was finished, second part which separates nasal cavity and oral cavity was constructed by the aid of the bulb.

Conclusion

When constructing an obturator prosthesis, making a detailed impression from the defect area can be performed by the aid of a metal frame, and an intraorally shaped extension that separates oral cavity from nasal cavity might be more effective for adaptation of the prosthesis.

Optimization of maxillary obturator thickness using a double-processing technique

Preservation of remaining structures is a primary goal of prosthetic rehabilitation. Continuously applied stresses on the remaining tissues from a large, heavy obturator jeopardize the health of the tissues, compromise the function of the prosthesis, and affect patient comfort. Various techniques have been described for hollowing the bulb of an obturator after processing to reduce its weight; however, access to the inner aspects of the bulb is limited, preventing adequate control of thickness of the walls. This article describes a double-processing technique for an obturator to optimize the weight and thickness of the bulb.

Zygoma implant-supported prosthetic rehabilitation after partial maxillectomy using surgical navigation: A clinical report

The rehabilitation of patients with acquired defects of the maxilla is a challenge in terms of reestablishing oronasal separation. In most patients these goals are met by means of prosthetic rehabilitation with an obturator prosthesis. If the remaining dentition does not offer sufficient retention and support, the placement of zygoma implants can enhance the stability of the prosthesis. Due to the anatomic intricacies of the zygomatic bone and the implant length, computer-supported navigated implant placement can be advantageous. In the following clinical report, a diabetic patient with a status of posthemimaxillectomy secondary to aspergillusis infection is presented, in whom a zygoma implant was placed using a CT scan-based navigation system. A special retentive anchoring abutment was used to integrate the zygoma implant into a telescopic crown-retained denture on the residual dentition. This tooth-implant-supported obturator prosthesis restored function and phonetics, as well as esthetics, for this young patient.

Effects of defect configuration, size, and remaining teeth on masticatory function in post-maxillectomy patients

The aim of this study was to investigate the correlation between the masticatory function and the maxillary defect configuration, size, and remaining teeth in post-maxillectomy patients restored with an obturator prosthesis. Fifty consecutive post-maxillectomy patients (mean age 67.0) participated in this study. The subjects consisted of 26 dentate and 24 edentulous patients. Data were collected from the patients' clinical records, diagnostic casts, and a questionnaire on masticatory function to evaluate the defect configuration, size, and the masticatory function scores associated with wearing obturator prostheses. The defect size was evaluated by the ratio of defect area to the horizontal impression area. The defect configuration was assessed according to Aramany's classification and separated into unilateral and bilateral defects. The multiple regression analysis and the Mann-Whitney U-test (P<0.05) were used to assess statistical significance. The Spearman's correlation coefficient by rank test was also used to detect correlation. The following conclusions were made: (i) The presence of teeth in the maxillary dentition and the different type of the defect configuration had significant correlation with the masticatory function score (r=0.616). (ii) The masticatory function scores of the subjects differed significantly with the presence of teeth in the maxillary dentition and the different types of defect configurations (P=0.005, P=0.002, respectively). (iii) There was significant correlation between the masticatory function score and the size of the defect area in the edentulous group (r=-0.648, P=0.001). The presence of teeth, the size and configuration of the defect influenced the masticatory function of post-maxillectomy patients with obturator prostheses.

Water absorption characteristics of two types of acrylic resin obturators

STATEMENT OF PROBLEM

The mechanisms of water accumulation in the inner space of a closed hollow obturator are not understood, and it is not known whether the porosity of acrylic resin is involved in these mechanisms.

PURPOSE

The purpose of this study was to evaluate water absorption by solid and closed hollow obturators and to determine the mechanisms of water accumulation in the inner space of the closed hollow obturator.

MATERIAL AND METHODS

Twenty solid and 20 closed hollow spherical specimens (30 mm in diameter) were fabricated from heat-polymerized acrylic resin (Acron Clear). Closed hollow specimens consisted of 2 hemispheres (30 mm in diameter, 1.5 mm in thickness) joined with autopolymerizing resin (Unifast II). Ten solid and 10 closed hollow specimens were immersed in distilled water at 37 degrees C, while the other specimens were stored in an atmosphere of 100% relative humidity at 37 degrees C. Each specimen was weighed every 24 hours for 180 days, and weight changes between each group were compared by 2-way ANOVA and the Tukey HSD test. Split-plot design ANOVA was used to compare the course of the weight change over 180 days (alpha=.05).

RESULTS

The weight of the closed hollow specimens increased immediately and became saturated by day 30, with an increase of 1.44% from the initial weight. Water accumulation was not observed inside the closed hollow specimen during the 180-day storage period. The weight of solid specimens increased more slowly than that of closed hollow specimens; by day 180 the weight of the latter had increased by 1.16%. However, no significant difference in changes in mean mass of the same type of specimen was observed between the 2 storage conditions.

CONCLUSION

These results suggest that water accumulation inside a closed hollow obturator is unrelated to the water absorption properties of the acrylic resin.

A hollow-bulb interim obturator for maxillary resection. A case report

The treatment of hemimaxillectomy patients include the construction of an interim obturator in the wound healing period. With the aim of simplifying this process, we describe construction of an obturator in a short single visit, in the dental chair with no need for impressions or for laboratory services. The obturator comprises: (i) the surgical obturator and (ii) a hollow light-cured resin bulb built onto the base, and providing a large surface for bonding of the soft reline material. The advantages of this approach are rapid construction and ease of ongoing adjustment during the healing process.

Fabrication of a closed hollow obturator

This article describes a technique for fabricating a closed hollow bulb obturator. It allows for control of the bulb's wall thickness and weight while not requiring any additional materials or time-consuming steps to the conventional processing procedures.

A titanium and visible light-polymerized resin obturator

Obturator prostheses are typically large, and their weight and size are often important design factors. This article describes the fabrication of an obturator prosthesis with a titanium framework and visible light-polymerized denture base resin. It is speculated that these low-density materials may produce prostheses lighter than similar ones made with conventional materials. An added advantage is that visible light-polymerizing resins facilitate relining.

1997 Judson C. Hickey Scientific Writing Awards. An innovative investment method for the fabrication of a closed hollow obturator prosthesis

An investment method is described for fabrication of a closed hollow obturator based on the use of three sections of a denture processing flask. The thickness of the obturator portion is minimized and all surfaces exposed to the oral cavity are processed with heat-polymerized acrylic resin. The technique eliminates additional steps noted in the literature, allowing for the prosthesis to be processed to completion from the wax trial denture. This technique provides a lightweight and seamless obturator and can be used for complete or partially edentulous cases. Clinical and laboratory time are minimized while fabricating a durable, virtually water-tight prosthesis that can be used alone or in conjunction with an extraoral prosthesis.