Application of Polyvinyl chloride sheet as delayed surgical obturator in maxillectomy defects secondary to mucormycosis- A case series.

It was a great challenge for the prosthodontist to rehabilitate and sustain the prosthesis in patients with bilateral maxillectomy defects due to mucormycosis seen with Covid-19 during second wave in India. In such extensive defects there was difficulty in retaining the obturator due to the absence of soft tissue or anatomical undercuts, condition of existing dentition, retained inferior turbinates and limitation in taking retention from defect side during healing phase. In such extensive maxillectomy defects, retention, stability and support can be enhanced by maximum preservation of hard and soft tissues, skin grafting and removal of inferior turbinates to provide a larger surface area for stress distribution. But here, in this case series, maxillectomy defects with retained inferior turbinates presented a problem in retaining the obturator prosthesis due to limitation in taking retention from the defect side. The conventional method of fabrication of obturator using autopolymerizing acrylic failed in terms of weight of the prosthesis and in gaining retention from the defect side during healing phase. Therefore, thermoplastic vacuum pressed Polyvinyl chloride sheet (PVC) was used for fabrication of delayed surgical obturator due to many merits conferred by it. Its light weight, non porous nature, easy adaptability, patient comfort, efficient undercut engagement, hygienic nature makes it a good treatment option. The main cocern was to close oro-nasal communication to eliminate the need of nasogastric tube and to prevent nasal regurgitation. In all cases, patients were comfortable with the obturator prosthesis in terms of adaptation and function.

Evaluation of active tactile sensibility in a single-tooth implant opposing a natural tooth with either an immediate or delayed functional loading protocol: A parallel design clinical study.

STATEMENT OF PROBLEM: High primary stability makes immediate loading more predictable, but immediately loaded implants are subjected to higher stresses and strains during the healing phase than implants that are left to heal for 3 months. Whether an earlier sensory-motor phenomenon with an immediate loading protocol helps to reduce the risk of overloading at the implant-bone interface is unclear. PURPOSE: The purpose of this concurrent parallel design clinical study was to evaluate and compare active tactile sensibility for a single-tooth implant opposing a natural tooth in the mandibular posterior region with either a delayed or immediate functional loading -protocol. MATERIAL AND METHODS: In this parallel group randomized trial, 2 test groups were formed: the DL group comprised 20 participants with the delayed loading protocol (loading after 3 months), and the IL group comprised 20 participants with the immediate loading protocol (loading within 2 days). Natural tooth-to-tooth contact on the side contralateral to the implant site (split mouth) in both test groups was used as a control to evaluate active tactile sensibility, which was evaluated in the test and control sites of both groups by using interocclusal articulating foils of varying thickness in maximum intercuspation. Active tactile sensibility was compared between the DL and IL groups at 3 and 6 months of follow-up. The nonparametric Mann-Whitney test was used for intergroup comparisons (P=.05). RESULTS: A significant difference was found for 8-µm- and 12-µm-thick articulating foil at 3 months and for 8-µm-thick foil at 6 months (P<.05), indicating a difference in active tactile sensibility between the DL and IL groups. No implant failure was recorded in this short clinical study. CONCLUSIONS: An immediate loading protocol can be performed in implants with sufficient primary stability. Upon loading, the IL group has shown more active tactile perception than the DL group.

Intraoral customized Z-spring-retained delayed surgical obturator for rare cases of bilateral subtotal maxillectomy.

While dealing with a grave second wave of ongoing pandemic COVID-19, India also saw a surge in cases of COVID-19-associated mucormycosis, a systematic fungal infection caused by the Mucorales species. Mucormycosis is a highly angioinvasive, rapidly spreading fungal infection. In numerous cases of mucormycosis, bilateral subtotal maxillectomy was performed due to unpredictable and indefinable advancement of fungus clinically. Effective obturation of bilateral maxillectomy defect is a difficult task and as this is a relatively uncommon surgical problem, insufficient data are available on the construction of delayed surgical obturator for such cases. The aim of this article is to discuss the design of Z-spring-retained delayed surgical obturator which is easy to fabricate, easy to rectify, cost-effective, and comfortable for the patients compared to previous spring-retained obturators. This surgical obturator is retained through Z-spring made of 1.02 mm thick wire. Due to the thick gauge, this spring counters postsurgery trismus and develops the seal between the acrylic plate and dorsum of the tongue during deglutition thus helps the patient in taking a soft diet initially. Novelty in this case is the design of the spring, which makes it beneficial for both patient and prosthodontist.

Comparative evaluation of extrasinus versus intrasinus approach for zygomatic implant placement.

Edentulism, a common problem can occur either as a congenital defect or acquired later due to dental caries, periodontitis, as a consequence of aging, maxillofacial trauma or post-ablation in tumor resections. The rehabilitation of the missing teeth can be done using dental implants. To overcome the deficiency of available bone, processes like sinus augmentation with substituted bone graft and Le Fort I osteotomy with interpositional bone graft have been described in the literature. In order to overcome the associated limitations with these procedures, implants were designed that can be placed in specific anatomical areas like zygoma. This study aims to compare two different types of surgical approaches (Intrasinus vs Extrasinus) for the placement of zygomatic implants to treat atrophic maxilla. The placement of zygomatic implant through both extrasinus and intrasinus approaches were evaluated on the basis of different parameters and it was observed that postoperative pain and swelling was significantly found in intra sinus approach as compared to extra sinus approach. However, in the intranasal approach, poor patient compliance or low satisfaction rate was observed as compared to extra sinus approach. On the basis of the results of the study and post operative evaluation based on various criteria, it was concluded that extra sinus approach has got an edge over intra sinus approach.

New records of Cantharellus species from the northwestern Himalayas of India.

This study investigated several collections of the genus Cantharellus (Cantharellaceae) from the northwestern Himalayas, India, on the basis of morphology and molecular data. Phylogenetic relationships and species limits were investigated by using nuclear ribosomal large subunit sequences (LSU). We recognized 13 species: Cantharellus appalachiensis Petersen, C. cibarius Fries, C. lateritius (Berk) Singer, C. miniatescens Heinem, C. minor Peck, C. pseudoformosus and seven species, C. applanatus sp. nov., C. elongatipes sp. nov., C. fibrillosus sp. nov., C. himalayensis sp. nov., C. indicus sp. nov., C. natarajanii sp. nov., and C. umbonatus sp. nov., as new to science. All these species are described and their taxonomy and ecology are discussed. In addition, a key is provided to all the recognized species. The phylogenetic analysis recovered 10 major supported clades of Cantharellus species.