Retention of implant retained obturator using two implant placement configurations for maxillectomy cases: in-vitro study

BACKGROUND

Implant-retained obturators for maxillectomy cases have several advantages over traditional obturators but prosthetic design for specific conditions after maxillary resection has several challenges and the appropriate implant placement configuration is essential for improving retention and the stability of the implant-retained obturator.

OBJECTIVES

The present study aimed to assess the retention force of using linear and nonlinear implant placement configurations using ball and socket attachment in implant-retained obturators at the initial retention and after simulation of six months of use.

MATERIALS AND METHODS

Two identical epoxy resin maxillary models of a completely edentulous unilateral maxillary defect (Brown's class IIb) were used for implant placement, in the first model three implants were arranged with linear placement configuration, and in the second model three implants were arranged in nonlinear placement configuration. For proper sample sizing, 26 models and obturator were used. Two equal groups of obturators (13 for each group) were constructed, each with a different implant placement configuration. Both groups used the same attachment design (a non-splinted ball attachment). Using a cyclic loading machine that served as a dental insertion and removal simulator, each study group was subjected to 500 tension-compression cycles simulating 6 months of use. Using the universal testing machine, each obturator was removed at a speed of 50 mm/min for the crosshead. peak load to dislodgement was measured at the initial retention and after the simulations of six months of use. Data were analyzed using independent and paired t-tests while percent change was analyzed using the Mann Whitney U test.

RESULTS

There were a statistically significant differences in retention between the nonlinear implant placement configuration for Brown's class IIb maxillectomy and the linear implant placement configuration at initial retention evaluation with p-value of < 0.0001 and after simulation of six months of usage with p-value of < 0.0001 Also, after simulation of 6 months of use group I lose - 24.87 (10.16) % of its retention while group II lose - 17.49 (7.78) %.

CONCLUSIONS

Non-linear implant placement is more retentive at the initial retention and after simulation of six months of use than linear and loses less retention after usage.

Virtual planning, guided surgery, and digital prosthodontics in the treatment of extended mandible chondrosarcoma

Chondrosarcoma is among the most common primary bone tumors in adults. In the mandible, chondrosarcoma is a very uncommon malignant cartilage-producing tumor. This case report shows how virtual planning combined with other digital technologies may improve masticatory function rehabilitation in patients with enlarged mandibular chondrosarcoma. The present study reports a case of a 52-year-old male patient who was initially diagnosed with a mandible chondroma, which was successfully excised with no evidence of malignant transformation. Nevertheless, the patient's symptoms recurred after 10 years, and a subsequent diagnosis of mandible chondrosarcoma was established, prompting the need for subtotal mandible resection and reconstruction with a fibula-free flap. Following a healing period, the patient underwent dental implant surgery to restore the mandibular dental arch, which was performed utilizing computer-aided design and computer-aided manufacturing technology, with fully guided implant placement facilitated by virtual planning. In this case report, the implant position data merging process is described from the digital impression and control model to ensure optimal passive fit of the full-arch zirconia prosthesis and discuss the importance of occlusal adjustments to avoid technical and biological complications. Virtual planning and digital technologies are crucial for the effective management of mandibular defects, allowing for accurate treatment and complete restoration of mandibular function. Their use leads to improved patient outcomes and quality of life. As technology advances, their importance in treating complex medical conditions is only expected to grow.

Prosthetic Oral Rehabilitation with CAD/CAM Suprastructures in Patients with Severe Tissue Deficits: A Case Series

This article presents the outcomes of prosthetic oral rehabilitation using CAD/CAM telescopic bar overdentures in patients with oral cancer (n = 3), severe facial trauma (n = 2), or various syndromes (n = 1), all suffering from severe tissue deficits and requiring complex and comprehensive oral rehabilitation. The aim was to assess the durability and functionality of implant-retained prosthetic structures, ensuring easy oral hygiene and minimizing specialized follow-up needs. The data for this study were sourced from a retrospective cohort at Helsinki University Hospital. The prosthetic reconstruction encompassed the Atlantis 2in1 and the Createch removable telescopic systems. Thus, 40 implants were placed (4 to 7 per patient), with prosthetic structures in the maxilla (n = 4 patients), in the mandible (n = 1), and in both jaws (n = 1). Two patients experienced no complications, two patients had part of the acrylic resin break, and one patient experienced loosening of the bar structure. All complications associated with prosthetic structures were successfully managed, and none of the implants were lost. The follow-up time ranged from 7 to 126 months. This rehabilitation is proved to be an effective solution for patients with complex oral conditions, facilitating both functional restoration and ease of maintenance. These findings underscore the importance of individualized treatment approaches in cases of tissue deficits.

Association of Patient Anthropometric Measurements and Dental Implant Treatment

Background

Dental implants are currently one of the most preferred treatment modalities for replacing missing teeth, as they are the most comparable to natural teeth. Even so, satisfaction with such treatment may differ depending on patient nature. The aim of this article was to examine the relationships between different anthropometric measurements on dental implant patient's satisfaction.

Methods and Material

Self-administered questionnaire (structured questions) were given to patients who had dental implant treatment to evaluate their satisfaction level with dental-implant treatment. Different anthropometric measurements were taken: body height; weight; body mass index (BMI); body composition; waist/hip ratio; and circumferences at the waist, hip, and neck.

Results

The overall BMI was 28.9±4.7 kg/m², there was a highly-significant difference in patient satisfaction among the different BMI groups (P< 0.000). The significant difference in most of those groups was between the obese group and the other groups. For neck circumference and waist/hip ratio, a significance difference between the normal weight and obese groups (P< 0.000) was found, while for percentage of muscle, the differences were between the overweight and obese groups (P< 0.000). According to BMI groups a highly significant difference in many patient satisfaction domains were found (P< 0.000). These significant differences were between the obese group and non-obese groups for most aspects of patient satisfaction. For patient satisfaction with final appearance, the normal BMI group differed significantly from the overweight BMI group (P=0.013). Additionally, for patient satisfaction with dentist performance and communication, the overweight BMI group showed significantly higher satisfaction than the normal BMI group (P=0.019). Body measurements were correlated negatively with overall patient satisfaction, and positively with satisfaction with prosthesis.

Conclusion

The obese group patients had the lowest rate of patient satisfaction. BMI and other body measurements can be used to predict patient satisfaction with the outcome of dental implant treatment.

Refabrication of an implant-retained obturator using the denture duplication technique in a bilateral maxillectomy patient with a free fibula osteocutaneous flap

PURPOSE

We aimed to introduce a simple method for refabrication of an implant-retained obturator using the denture duplication technique while retaining the custom abutments for a patient who underwent bilateral maxillectomy and reconstruction with a free fibula osteocutaneous flap. We have proposed this technique to facilitate the impression-making procedure for this extensive maxillary defect and to avoid lengthy and complicated laboratory procedures.

METHODS

A custom tray was developed by duplicating the fitting surface of an old obturator using silicone putty. The tray was used for a bite-pressure impression wherein both definitive impression and jaw relation were obtained simultaneously, reducing the time required for the placement of a new obturator.

CONCLUSIONS

We used the denture duplication technique to refabricate an implant-retained obturator while retaining the custom abutments. Decreased chairside time, fewer visits, the use of easily available materials, and uncomplicated laboratory procedures make this technique more economical and acceptable for patients. Using this approach, the patient was able to use the old prosthesis until the delivery of the new prosthesis. The replacement obturator that was developed using this method maintained an acceptable level of oral function.

Oral Health Management and Rehabilitation for Patients with Oral Cancer: A Narrative Review

Surgery is the current first choice for oral cancer treatment. Intensity-modulated radiation therapy, molecular targeted drugs, and immune checkpoint inhibitors are still used as adjuvant therapy for advanced cancer. In addition, postoperative rehabilitation and multidisciplinary treatment have also been developed in recent years. Multidisciplinary team approaches and supportive care in oral cancer treatment reportedly shorten the time to treatment and improve outcomes. Although there is enough evidence confirming the role of oral and maxillofacial surgeons, dentists, and dental hygienists in supportive care in oral cancer treatment, there are very few systematic studies. In particular, oral health management is a concept that encompasses oral function management, oral hygiene management, and oral care during oral cancer treatment. We provide a narrative review focusing on oral health management from a multidisciplinary and supportive care perspective, applicable in oral cancer treatment.

Health-related quality of life in maxillectomy patients undergoing dentoalveolar rehabilitation

OBJECTIVES

Surgical resection of the maxilla impairs aesthetics, speech, swallowing, and mastication. Maxillary reconstruction is increasingly performed with virtual surgical planning (VSP) to enhance functional dental rehabilitation with a conventional denture or osseointegrated implants. The aim of this study was to determine whether dental status and VSP is associated with health-related quality of life (HRQOL) and function in patients who have undergone maxillectomy.

MATERIALS AND METHODS

A cross-sectional study was conducted among patients who underwent free flap reconstruction or obturation of the maxilla between July 2009 and December 2020. The FACE-Q Head and Neck Cancer (FACE-Q) module, M.D. Anderson Dysphagia Inventory (MDADI), and Speech Handicap Index (SHI) were used to evaluate HRQOL.

RESULTS

Forty-three patients (response rate 59%) completed questionnaires and 48% underwent dental rehabilitation. In Okay Class II and III defects, adjusting for the effect of radiotherapy and time from surgery, there was a positive association between denture status and FACE-Q smiling (p = 0.020), eating (p = 0.012), smiling (p = 0.015), and MDADI global (p = 0.015), emotional (p = 0.027), functional (p = 0.028), and composite (p = 0.029) scores. VSP was associated with FACE-Q swallowing (p = 0.005), drooling (p = 0.030), eating (p = 0.008), smiling (p = 0.021), MDADI global (p = 0.017), emotional (p = 0.041), functional (p = 0.040), composite (p = 0.038), and SHI total scores (p = 0.042).

CONCLUSIONS

Dentoalveolar rehabilitation and VSP were associated with higher HRQOL scores relating to eating and drinking, smiling, and speaking.

Postoperative oral dysfunction following oral cancer resection and reconstruction: A preliminary cross-sectional study

OBJECTIVES

Oral cancer treatment reportedly causes decreased oral function, but few studies have examined the effects of oral cancer treatment on oral function in depth. This study aimed to comprehensively evaluate the oral function after treatment and classify the conditions related to oral dysfunction in patients with oral cancer.

MATERIALS AND METHODS

We recruited participants, collected their background data, and evaluated their oral function from September 2019 to March 2021. Principal component analysis was used to identify the components of oral function measurement and oral health perception. Receiver operating characteristic analysis was performed to investigate the accuracy of oral function measurements in predicting oral intake and nutritional status.

RESULTS

Fifty patients treated for oral cancer, including 33 (66.0%) males and 17 (34.0%) females, were included. Their median age was 71.0 years (interquartile range: 63.0-76.0). There were significant differences in oral dryness between males and females, occlusal force among different age groups, tongue pressure based on the tumor stage and performance of reconstructive procedures, and masticatory function and Eating Assessment Tool scores based on whether radiotherapy was performed (P < 0.05). The principal component analysis proposed that oral function measurements and subjective oral health perception could be divided into three main components (transport, oral hygiene, and occlusion type), which explain 61.5% of the variance of the phenomenon.

CONCLUSION

A significant decrease in oral function after oral cancer treatment should be diagnosed as postoperative oral dysfunction. Postoperative oral dysfunction can be classified into three types, each of which may present with different pathologies.

Dentoalveolar outcomes in maxillary reconstruction: A retrospective review of 85 maxillectomy reconstructions

BACKGROUND

Although microvascular free flaps are often used to reconstruct maxillary defects, dentoalveolar rehabilitation is arguably less common despite its importance to midface function and aesthetics. The aim of this study is to review the contemporary management of maxillary defects in a single quaternary referral institution to identify factors that assist or impede dentoalveolar rehabilitation.

METHODS

A retrospective review of maxillary reconstructions performed between February 2017 and December 2020 was performed. Patient characteristics, defect classification, operative techniques, complications and dentoalveolar outcomes were recorded.

RESULTS

A total of 85 maxillary reconstructions were performed in 73 patients. Of the 64 patients where dental rehabilitation was required, 31 received a functional denture (48%) with 24 (38%) being implant-retained. Significant predictors of successful rehabilitation included the use of virtual surgical planning (VSP; 86% vs. 25%, p < 0.001), preoperative prosthodontic assessment (82% vs. 21%, p < 0.001), prefabrication (100% vs. 40%, p = 0.002) and use of the zygomatic implant perforator flap technique (100% vs. 39%, p = 0.001). Preoperative prosthodontic consultation was associated with 21-fold increase in the odds of rehabilitation (odds ratio 20.9, 95% confidence interval 6.54-66.66, p < 0.005).

CONCLUSION

Preoperative prosthodontic evaluation, VSP and reconstructive techniques developed to facilitate implant placement are associated with increased dental rehabilitation rates. Despite using an institutional algorithm, functional dentures are frequently prevented by factors including soft tissue constraints, disease recurrence and patient motivation.

Retrospective long-term clinical evaluation of implant-prosthetic rehabilitations after head and neck cancer therapy

OBJECTIVE

To assess clinical and patient-reported outcomes of implant-prosthetic rehabilitations in patients with a history of head-neck cancer (HNC), treated with tumor resection without (TR) or with adjuvant radiotherapy (TR/RT). A healthy cohort rehabilitated with the same reconstructive protocols served as control group (C).

MATERIALS AND METHODS

A total of 28 women and 29 men were considered in the present retrospective study. Participants received 322 implants, finally supporting 79 prosthetic reconstructions. Primary outcome was the assessment of implant and prosthetic survival rates. Furthermore peri-implant soft tissue parameters (attached peri-implant mucosa, AM; modified bleeding and plaque indices, mBI/mPI; probing depth, PD) and prosthetic technical complications were documented. Patient-reported outcome measures (PROMs) by means of visual analog scales (VAS) and the Oral Health Impact Profile German 14 form (OHIP G14) were collected. For statistical purposes Chi-square and Mann-Whitney-U-Test were adapted.

RESULTS

After a mean follow-up of 81.2 ± 50.3 months, implant survival rate was 98.1% (HNC-TR), 98.2% (HNC-TR/RT) and 100.0% (C), respectively (four implants failed in the HNC groups). HNC-TR/RT showed significant higher mPI and mBI compared to C. Within HNC-TR/RT, vestibuloplasty significantly reduced mBI and PD values. No failures occurred at the prosthetic level. Overall, higher VAS scores were reported for bar- compared with Locator-retained prostheses. Furthermore, increased OHIP G14 values resulted for HNC-TR/RT.

CONCLUSIONS

High survival rates on implant and prosthetic level were observed. The use of soft tissue grafts resulted in stabilization of the peri-implant mucosa in irradiated patients. In terms of retention and chewing ability, participants preferred bars over Locator attachments.

Stress distribution on different bar materials in implant-retained palatal obturator

Implant-retained custom-milled framework enhances the stability of palatal obturator prostheses. Therefore, to evaluate the mechanical response of implant-retained obturator prostheses with bar-clip attachment and milled bars, in three different materials under two load incidences were simulated. A maxilla model which Type IIb maxillary defect received five external hexagon implants (4.1 x 10 mm). An implant-supported palatal obturator prosthesis was simulated in three different materials: polyetheretherketone (PEEK), titanium (Ti:90%, Al:6%, V:4%) and Co-Cr (Co:60.6%, Cr:31.5%, Mo:6%) alloys. The model was imported into the analysis software and divided into a mesh composed of nodes and tetrahedral elements. Each material was assumed isotropic, elastic and homogeneous and all contacts were considered ideal. The bone was fixed and the load was applied in two different regions for each material: at the palatal face (cingulum area) of the central incisors (100 N magnitude at 45°); and at the occlusal surface of the first left molar (150 N magnitude normal to the surface). The microstrain and von-Mises stress were selected as criteria for analysis. The posterior load showed a higher strain concentration in the posterior peri-implant tissue, near the load application side for cortical and cancellous bone, regardless the simulated material. The anterior load showed a lower strain concentration with reduced magnitude and more implants involving in the load dissipation. The stress peak was calculated during posterior loading, which 77.7 MPa in the prosthetic screws and 2,686 με microstrain in the cortical bone. For bone tissue and bar, the material stiffness was inversely proportional to the calculated microstrain and stress. However, for the prosthetic screws and implants the PEEK showed higher stress concentration than the other materials. PEEK showed a promising behavior for the bone tissue and for the integrity of the bar and bar-clip attachments. However, the stress concentration in the prosthetic screws may represent an increase in failure risk. The use of Co-Cr alloy can reduce the stress in the prosthetic screw; however, it increases the bone strain; while the Titanium showed an intermediate behavior.

Head and Neck Osteosarcoma-The Ongoing Challenge about Reconstruction and Dental Rehabilitation

Head and Neck osteosarcoma is an uncommon disease. Hitherto, the treatment is surgical resection and survival is influenced by the presence of free margins. However, the dimension of the resection may represent a hurdle for an adequate Quality of Life (QOL). Maxillofacial district is a narrow space where the function, esthetics and patient’s relational skills fit together like the gears of a clock. The functional results depend on the type of reconstruction and prosthetic rehabilitation that are both important to guarantee a good aesthetic result and finally increase the patient’s self-esteem. This study aims to report our experience about head and neck (HN) osteosarcoma focusing the attention on reconstructive and dental-rehabilitative problems. It is a retrospective study all patients were surgically treated in our department. Subjects with histological diagnosis of HN osteosarcoma, treated between 2005 and 2017 were included. The demographic characteristics, surgical treatment, eventually secondary reconstruction and prosthetic rehabilitation, performed in the same department, have been collected. The QOL was assessed through the EORTC QLQ-H&N35 (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Head and Neck 35) questionnaire. Fifteen patients were enrolled, eight received a free flap microsurgical reconstruction. Dental rehabilitation was performed in five cases and a mobile prosthesis was always delivered. Eighteen implants were inserted in fibula bones for three patients; highly porous implants were used.

Mandibular dental implant placement immediately after teeth removal in head and neck cancer patients

BACKGROUND

Little is known about immediate implant placement in head and neck cancer patients. We studied implant survival and functional outcomes of overdentures fabricated on implants placed immediately after removal of the lower dentition during ablative surgery or preceding primary radiotherapy (RT).

METHODS

Inclusion criteria were primary head and neck cancer, dentate lower jaw, and indication for removal of remaining teeth. Two implants to support a mandibular overdenture were placed immediately after extraction of the dentition during ablative surgery, or prior to starting primary radiotherapy. Standardized questionnaires and clinical assessments were conducted (median follow-up 18.5 months, IQR 13.3).

RESULTS

Fifty-eight implants were placed in 29 patients. Four implants were lost (implant survival rate 93.1%). In 9 patients, no functional overdenture could be made. All patients were satisfied with their dentures.

CONCLUSIONS

Combining dental implant placement with removal of remaining teeth preceding head neck oncology treatment results in a favorable treatment outcome.

What is the optimal timing for implant placement in oral cancer patients? A scoping literature review

BACKGROUND

Oral cancer patients can benefit from dental implant placement. Traditionally, implants are placed after completing oncologic treatment (secondary implant placement). Implant placement during ablative surgery (primary placement) in oral cancer patients seems beneficial in terms of early start of oral rehabilitation and limiting additional surgical interventions. Guidelines on the ideal timing of implant placement in oral cancer patients are missing.

OBJECTIVE

To perform a scoping literature review on studies examining the timing of dental implant placement in oral cancer patients and propose a clinical practice recommendations guideline.

METHODS

A literature search for studies dealing with primary and/or secondary implant placement in MEDLINE was conducted (last search December 27, 2019). The primary outcome was 5-year implant survival.

RESULTS

Sixteen out of 808 studies were considered eligible. Both primary and secondary implant placement showed acceptable overall implant survival ratios with a higher pooled 5-year implant survival rate for primary implant placement 92.8% (95% CI: 87.1%-98.5%) than secondary placed implants (86.4%, 95% CI: 77.0%-95.8%). Primary implant placement is accompanied by earlier prosthetic rehabilitation after tumor surgery.

CONCLUSION

Patients with oral cancer greatly benefit from, preferably primary placed, dental implants in their prosthetic rehabilitation. The combination of tumor surgery with implant placement in native mandibular bone should be provided as standard care.

Systematic review of literature: functional outcomes of implant-prosthetic treatment in patients with surgical resection for oral cavity tumors

No improvement in quality of life after implant prosthetic reconstruction following resective surgery for cancer.