Kanchan P. Dholam

Dental implants in irradiated jaws: a literature review.

Surgical treatment of head and neck cancer frequently results in defects that challenge conventional prosthetic rehabilitation. Successful rehabilitation using tissue supported dentures in such cases has been reported to be less than 20%. With the loss of jaw bones and thus the support, there is loss of retention to a great deal. Also, teeth loss on the side of the defect adds to failure in retention. Scar tissue formation, deviation of jaw due to muscle pull, decreased mouth opening, loss of sulcus and non vertical force are some of the common adversaries of jaw resection especially mandibular resection which pose great limitation on the stability and success of prospective prosthetic rehabilitation. The advent and application of biologically acceptable implants in clinical dentistry has contributed to restoring the defects of the deficient maxillofacial systems. Surgical intervention in patients who had received head and neck irradiation is preferably avoided as it has been associated with decreased healing and increased potential for development of osteoradionecrosis. Hence an implant as an option when surgical field has received tumerocidal radiation is empirically excluded. The purpose of this article is to review the studies and reports published in various journals related to osseointegrated implant rehabilitation in irradiated bones.

Effectiveness of Fluoride Varnish Application as Cariostatic and Desensitizing Agent in Irradiated Head and Neck Cancer Patients

Objective. To evaluate the effectiveness of three-month fluoride varnish application on radiation caries and dental sensitivity and to assess compliance to three-month fluoride varnish application. Materials and Methods. 190 irradiated head and neck cancer patients were randomly selected and reviewed retrospectively. Oral prophylaxis, fluoride varnish application, and treatment of dental caries were done prior to radiation therapy. Patients were followed up at every three months for dental evaluation and fluoride varnish application. Decayed-missing-filling-teeth indices, dental sensitivity, and compliance to fluoride varnish application were noted for fifteen months and analyzed statistically. Results. Significant increase in decayed-missing-filling-teeth index was seen at nine (P = 0.028), twelve (P = 0.003) and fifteen (P = 0.002) months follow-up. However, the rate of increase in decayed-missing-filling-teeth indices was 1.64/month which is less than the rate mentioned in the literature (2.5/month). There was no significant effect of sex (P = 0.952) and surgery (P = 0.672) on radiation caries, but site of disease (P = 0.038) and radiation dose (P = 0.015) were found to have statistically significant effect. Dental sensitivity decreased from 39% at 3 months to 25% at 15 months followup. 99% compliance to fluoride varnish application was seen till six months followup which decreased to 46% at fifteen months. Conclusion. Three-month fluoride varnish application is effective in decreasing radiation caries and sensitivity and has good compliance.

Implant-retained dental rehabilitation in head and neck cancer patients: an assessment of success and failure.

Background: This study aimed to evaluate the rate of osseointegration (ROI) and overall success rate (OSR) of implants placed in native and grafted jaws with or without radiotherapy at a 5-year follow-up in Indian head and neck cancer patients. Material and Methods: Thirty head and neck cancer patients from various socioeconomic strata were accrued. Eighty-five implants were inserted in 17 native and 13 grafted jaws. Nineteen patients received radiation therapy. A 5-year follow-up ROI and OSR of implants were reported. Results: The 5-year ROI and OSR were 88% and 77%, respectively. ROI was 93% for grafted, 85% for native, 83% for irradiated, and 100% for nonirradiated jaws. OSR was 73% for grafted, 80% for native, 71% for irradiated, and 89% for nonirradiated jaws. Patients from higher socioeconomic strata had higher OSR (92%) as compared with those belonging to lower socioeconomic strata (65%). Conclusion: The failure rate observed in this study was 24% for implants placed in head and neck cancer patients at a 5-year follow-up.

Long Term Rehabilitation of a Total Glossectomy Patient

Malignant tumours of the oral cavity that require resection of the tongue result in severe deficiencies in speech and deglutition. Speech misarticulation leads to loss of speech intelligibility, which can prevent or limit communication. Prosthodontic rehabilitation involves fabrication of a Palatal Augmentation Prosthesis (PAP) following partial glossectomy and a mandibular tongue prosthesis after total glossectomy [1]. Speech analysis of a total glossectmy patient rehabilitated with a tongue prosthesis was done with the help of Dr. Speech Software Version 4 (Tiger DRS, Inc., Seattle) twelve years after treatment. Speech therapy sessions along with a prosthesis helped him to correct the dental sounds by using the lower lip and upper dentures (labio-dentals). It was noticed that speech intelligibility, intonation pattern, speech articulation and overall loudness was noticeably improved.

Effective rehabilitation after partial glossectomy.

ObjectiveThe surgical treatment of cancer of tongue results in speech deficits. Speech disorders in the glossectomised patients fall into, categories of impaired articulation, reduced speech intelligibility, altered oral & nasal resonance, impaired voice quality & reductions in global speech proficiency. Since speech is a social tool, its most significant measurements start with the degree to which it can be understood.MethodsThis study was conducted at Tata Memorial Hospital, Mumbai, India, An incidental sample of 25 patients was selected for this study. Different questionnaires specially devised for this study were used to assess patients’ speech & deglutition post-operatively. The data was collected 3 months after surgery of these patients.ResultsStudies have indicated that larger the segment of the tongue, the greater is the distortion of speech & difficulty in deglutition. All functions associated with the interaction of the tongue with the related anatomy of the head & neck were severely impaired following glossectomy. The rehabilitation plan for partial glossectomy patients depended upon the assessment of their post-operative articulation level, education, job, age, family & motivation.

A Novel Obturator Device for Management of Dilated Trachea-esophageal Puncture Tract Fistulas

Voice rehabilitation in laryngectomized patients by tracheoesophageal puncture is a time tested technique. In some patients the tracheoesophageal puncture gets inordinately dilated leading to leakage around the prosthesis. Most of these fistulas are managed by a variety of conservative treatments like temporary removal of prosthesis, placement of silastic ring over the prosthesis, placement of nasogastric tube and airway protection by a cuffed tracheostomy tube. Intractable fistulas are tackled by surgical closure but are fraught with failures. We hereby suggest a novel temporary obturator that can be can be easily made at a very low cost in any hospital having prosthetic rehabilitation services and obviates the need for a tracheostomy tube, nasogastric tube and repeated hospital visits.

Technical considerations in rehabilitation of an edentulous total glossectomy patient.

The technician by virtue of his profession plays an important role in fabricating silicone tongue prosthesis for a total glossectomy patient. The technician, with his skills and specialized knowledge in handling material, plays a valuable role as a member of the oncology team. A patient with total glossectomy can be rehabilitated by silicone tongue prosthesis as an aid to improve his speech and swallowing. This paper describes the technical steps involved in fabricating a silicone tongue prosthesis for an edentulous total glossectomy patient.

Restoration of nasal defect with implant-retained nose prosthesis

In patients with the loss of facial structures due to neoplasms, trauma or congenital deformities, reconstruction using autogenous tissue is a complex and multistage procedure with an unsatisfactory outcome. Prosthetic reconstruction becomes the treatment modality of choice in such cases. A prosthesis fabricated on an osseointegrated implant is an excellent method to rehabilitate such patients. In these procedures, permanent percutaneous connections anchored in the underlying bone support the facial prosthesis (auricular orbital or nasal prosthesis).

Implant-retained orbital prosthesis

An 11-year-old woman reported with rhabdomyosarcoma of the right eye, with cranial involvement. The patient had received multimodal treatment comprising chemotherapy and orbital exenteration. Implant-retained orbital restoration was considered after a decade of the curative treatment. One implant was placed in the supraorbital ridge and the other implant, in the frontal process of the zygoma. Subsequently, implant-supported magnet-retained prosthesis was fabricated.

Osteogenic Nanofibrous Coated Titanium Implant Results in Enhanced Osseointegration: In Vivo Preliminary Study in a Rabbit Model

A titanium implant surface when coated with biodegradable, highly porous, osteogenic nanofibrous coating has shown enhanced intrinsic osteoinductive and osteoconductive properties. This coating mimics extracellular matrix resulting in differentiation of stem cells present in the peri-implant niche to osteoblast and hence results in enhanced osseointegration of the implant. The osteogenic nanofibrous coating (ONFC) consists of poly-caprolactone, gelatin, nano-sized hydroxyapatite, dexamethasone, ascorbic acid and beta-glycerophosphate. ONFC exhibits optimum mechanical properties to support mesenchymal stem cells and steer their osteogenic differentiation. ONFC was subjected to various characterization tests like scanning electron microscopy, Fourier-transform infrared spectroscopy, x-ray diffractometry, thermal degradation, biomineralization, mechanical properties, wettability and proliferation assay. In pre-clinical animal trials, the coated implant showed enhanced new bone formation when placed in the tibia of rabbit. This novel approach toward implant bone integration holds significant promise for its easy and economical coating thus marking the beginning of new era of electrospun osteogenic nanofibrous coated bone implants.