Effect of rehabilitation by using the shortened dental arch concept on the thickness of the masseter muscle and occlusal force: A pilot study.

STATEMENT OF PROBLEM: Knowledge of the effect of a shortened dental arch on masseter muscle thickness and occlusal force is sparse but could help clinicians understand how a shortened dental arch might affect the stomatognathic system. PURPOSE: The purpose of this pilot clinical study was to evaluate and compare the masseter muscle thickness and occlusal force of participants rehabilitated by using a shortened dental arch with matched completely dentate individuals. MATERIAL AND METHODS: Twelve partially edentulous participants with a minimum of 1 posterior occluding pair on each side of the arch were enrolled in the study. The mandibular arch of these participants was rehabilitated by using a single posterior mandibular implant crown (group S). The maxillary arch of all participants in group S was intact. Masseter muscle thickness (cm) and occlusal force (N) were recorded before (T1) and 6 months after implant rehabilitation (T2) for each participant. Twelve participants were selected as controls (group C). They were matched for age, sex, height, and weight with group S and evaluated for masseter muscle thickness and occlusal force. Masseter muscle thickness was evaluated by using ultrasonography during the rest position and maximum volumetric clenching. Occlusal force was measured with an occlusal force measuring appliance. All recordings were done for the left and right sides of the arch. Descriptive analysis was followed by comparison between groups and within group S by using the paired t test (α=.05). RESULTS: Higher masseter muscle thickness and higher occlusal force were observed in group C than in group S before and after rehabilitation. An increase in masseter muscle thickness in the rest position and in maximum volumetric clenching was observed within group S after rehabilitation. Before rehabilitation, a difference in the masseter muscle thickness between group S and group C was statistically significant for the left side at the rest position (P=.017) and during maximum volumetric clenching (P=.016). After rehabilitation, the difference between group S and group C was not statistically significant for masseter muscle thickness at the rest position (P=.890 for right side and P=.555 for left side) and during maximum volumetric clenching (P=.109 for right side and P=.755 for left side). The difference in occlusal force between group S and group C was statistically significant for the right side and left side (P<.001) before rehabilitation and statistically not significant after rehabilitation (P=.161 for the right side and P=.134 for the left side). CONCLUSIONS: Rehabilitation following the concept of a shortened dental arch increased masseter muscle thickness and occlusal force in partially edentulous individuals, making the masseter muscle thickness and occlusal force comparable with those of a completely dentate arch.

Influence of Thermocycling and Surface Treatments on the Flexural Strength of Denture Base Resin: An In Vitro Study.

AIM: The purpose of this study was to evaluate the flexural strength of heat polymerized denture base resin after thermocycling and different surface treatments done prior to repair or relining. MATERIALS AND METHODS: In this in vitro study, 80 specimens were made with heat-polymerized denture base resin and thermocycled (500 cycles between 5 and 55 °C). The specimens were divided in four groups based on different types of surface treatment: group I (control group: without surface treatment), group II (chloroform for 30 seconds), group III [methyl methacrylate (MMA) for 180 seconds], and group IV (dichloromethane for 15 seconds). The flexural strength was assessed using a Universal testing machine with three-point bending test. The obtained data were subjected to statistical analysis using one-way ANOVA and post-hoc tests. RESULTS: The values of average flexural strength of denture base resin measured were as follows: group I: 111.1 MPa, group II: 86.9 MPa, group III: 73.1 MPa, and group IV: 78.8 MPa. Groups II and IV possessed superior flexural strength than group III. The maximum values were observed with the control group. CONCLUSION: The flexural strength of heat-polymerized denture base resin gets affected by different surface treatments done prior to relining procedures. Lowest flexural strength was obtained when treated with MMA monomer for 180 seconds as compared to the other etchants used. CLINICAL SIGNIFICANCE: Prior to denture repair procedures, operators must choose the chemical surface treatment judiciously. It should not affect the mechanical properties such as flexural strength of denture base resins. Reduction in flexural strength of polymethyl methacrylate (PMMA) denture base can predispose the prosthesis to deteriorated performance when in function.

Cranioplast fabrication in a comatose patient: A clinical report.

Cranioplasty may be necessary after decompressive craniectomies to aid in the restoration of the esthetic, morphological, functional, and psychosocial stability of those affected. This clinical report describes the management of a comatose road traffic accident victim with a history of autogenous cranial implant failure after decompressive craniectomy. The challenges posed by the nonambulatory state of the patient and his inability to follow commands were overcome by using reverse engineering and rapid prototyping to fabricate a 3D patient-specific polymethylmethacrylate cranial implant. A digital evaluation technique with grids as measuring tools was successfully implemented in the patient's absence. The use of a custom clamp flask aided in the accommodation and subsequent investing, dewaxing, and polymerization of the carved cranial wax pattern. As a result, a custom cranioplast with optimum marginal fit, acceptable contour, adequate thickness, and reduced surgical duration of placement was obtained through a successful combination of conventional and digital techniques.

Evaluation of the wear of glazed and polished zirconia crowns and the opposing natural teeth: A clinical pilot study.

STATEMENT OF PROBLEM: Clinical studies on the wear properties of different zirconia surfaces are lacking. Selecting a surface that causes and undergoes minimal wear will help improve clinical outcomes. PURPOSE: The purpose of this clinical study was to evaluate and compare the wear over 1 year use of glazed zirconia (GZ) and polished zirconia (PZ) crowns opposing natural enamel and the wear of natural enamel opposing PZ and GZ crowns. MATERIAL AND METHODS: This prospective, split mouth, randomized clinical trial included 14 participants requiring complete coverage crowns on first molars, bilaterally, in a completely dentate mandibular arch. GZ and PZ crowns were cemented according to a randomization chart. Polyvinyl siloxane impressions were made immediately and 1 year after the cementation of the crowns. The respective casts were scanned by using a 3D scanner and a software program to measure the amount of linear wear of zirconia crowns and opposing natural teeth. Wear was observed in 8 groups: PZ crowns, GZ crowns, natural enamel opposing natural enamel in the molar and premolar regions (NE-M and NE-PM), natural enamel opposing PZ crowns in the molar region (NE-PZ-M), natural enamel opposing GZ crowns in the molar region (NE-GZ-M), natural enamel opposing PZ crowns in the premolar region (NE-PZ-PM), and natural enamel opposing GZ crowns in the premolar region (NE-GZ-PM). A descriptive analysis was followed by comparison between groups by using a repeated-measure ANOVA with post hoc adjustments (α=.05). RESULTS: The mean wear (µm) observed was as follows (in ascending order): PZ crowns (13 ±3), NE-PM (13 ±1), GZ crowns (27 ±9), NE-M (34 ±3), NE-PZ-PM (44 ±18), NE-PZ-M (63 ±22), NE-GZ-PM (69 ±21), NE-GZ-M (113 ±33). Wear of GZ and PZ crowns was less than wear of NE-M. The difference was statistically significant when comparing PZ with NE-M (P<.001, CI=-17 to -24). Wear of NE-GZ-M and NE-PZ-M was higher than wear of NE-M, with a statistically significant difference (P<.001, CI=-49 to -107 and P =.004, CI=-8 to -49, respectively). Wear of NE-GZ-M was more than that of NE-PZ-M, and the difference was statistically significant (P<.001, CI=-68 to -32). Wear of NE-PZ-PM and NE-GZ-PM was also more than the wear of NE-PM, and the difference was statistically significant (P<.001, CI=-17 to -43 and P<.001, CI=-39 to -70). CONCLUSIONS: PZ and GZ crowns wear substantially with time, with lesser wear observed in PZ crowns. PZ and GZ crowns also cause more wear in opposing natural enamel than natural enamel antagonists, with the highest wear caused by GZ crowns.

Prosthetic rehabilitation of resected orbit in a case of mucormycosis.

The design of orbital prosthesis to rehabilitate patients with orbital exenteration depends on the underlying clinical condition, material chosen for prosthesis, method of retention of the prosthesis, and and preference of the patient. Rehabilitation of a patient with orbital exenteration due to mucormycosis has been described by fabricating a prosthesis that used polymethyl methacrylate (to fabricate a conformer) and silicone material (to fabricate prosthetic superstructure). The two-component prosthesis was designed to attain dual mechanical retention using an anatomic undercut (conformer) and manually created mechanical undercut (prosthetic superstructure). The objective was to maintain the biological health of the underlying postsurgical tissue, longevity of the prosthesis, optimal esthetics, and adequate retention.

Cameo surface recording in complete denture fabrication using transcutaneous electrical nerve stimulation: A clinical report.

Severe bone loss in patients with complete edentulism poses a treatment challenge. In fabricating a denture, the stability of the prosthesis must be enhanced by recording the cameo surface within the confines of the physiological position of the cheek and tongue muscles (the neutral zone) and by shaping it accordingly. The treatment of a patient with a completely edentulous maxillary arch and severe maxillary anterior bone loss is described. The cameo surface was recorded within the physiological limits during the fabrication of a complete denture by using transcutaneous electrical nerve stimulation (TENS).

Technique for adapting a spacer for a custom impression tray.

A method of adapting a spacer for the custom trays used to make a definite impression for complete dentures is presented. The technique can be used under a variety of conditions and offers several advantages.

Correction of cheek biting in a dentate patient.

Postsurgical injury by teeth to oral mucosa (reconstructed by a flap) can lead to ulceration and subsequent infection at the reconstructed site. A prompt intervention by fabricating a specially designed prosthesis to deflect the reconstruction flap away from the occluding teeth has been described for the treatment of cheek biting in the present clinical report.

Correction of microstomia in an edentulous patient.

The problem of small oral aperture is big. Irrespective of the etiology, this problem may be overcome by adjunctive therapies in the form of prosthesis, surgery, or exercise. A patient is described with this problem, which was overcome by revisiting the 3 adjunctive therapies including a commissural stent designed with the patient's edentulous state in mind.

An Alternate Vista in Rehabilitation of Cranial Defects: Combining Digital and Manual Techniques to Fabricate a Hybrid Cranioplast.

The desired features of a cranioplast include providing an acceptable contour, continuity with the remaining skull (marginal adaptation), improvising the aesthetic outcome, providing a strengthened prosthesis to avoid fracture in case of repeat trauma, and protecting the remaining neurological structures. Combining digital and manual techniques to fabricate a hybrid polymethylmethacrylate cranioplast during the rehabilitation of a pediatric patient with cranial defect has been described. Utilization of digital techniques (rapid prototyping to obtain skull analog) and manual (hand) sculpting of the prosthesis strengthened with glass fiber enabled the authors to fabricate a hybrid cranioplast. Satisfactory outcome was achieved.

Alleviating speech and deglutition: Role of a prosthodontist in multidisciplinary management of velopharyngeal insufficiency.

Surgical resection of soft palate due to cancer affects the effective functioning of the velopharyngeal mechanism (speech and deglutition). With the loss of speech intelligibility, hyper resonance in voice and impaired function of swallowing (due to nasal regurgitation), there is a depreciation in the quality of life of such an individual. In a multidisciplinary setup, the role of a prosthodontist has been described to rehabilitate such patients by fabrication of speech aid prosthesis. The design and method of fabrication of the prosthesis are simple and easy to perform. The use of prosthesis, together with training (of speech) by a speech pathologist resulted in improvement in speech. Furthermore, an improvement in swallowing had been noted, resulting in an improved nutritional intake and general well-being of an individual. The take-home message is that in the treatment of oral cancer, feasible, and rapid rehabilitation should be endeavored in order to make the patient socially more acceptable. The onus lies on the prosthodontist to practise the same in a rapid manner before the moral of the patient becomes low due to the associated stigma of cancer.

Role of a dentist in comprehensive management of a comatose patient with post traumatic head injury and neuropathological chewing.

Injury of the head and neck region can result in substantial morbidity. Comprehensive management of such patients requires team work of several specialties, including dentists. A young female patient with extensive loss of cranium and associated pathological chewing was referred to the dental department. The lost cranium was replaced by a custom-made, hand-fabricated cranioplast. Trauma due to pathological mastication was reduced by usage of a custom-made mouthguard. Favorable results were seen in the appearance of the patient and after insertion of the mouthguard as evidenced in good healing response. The intricate role of a dental specialist in the team to manage a patient with post traumatic head injury has been highlighted. The take away message is to make the surgical fraternity aware of the scope of dentistry in the comprehensive management of patients requiring special care.

"Weighing it Down": Technique to Reduce the Weight of an Obturator.

Objective: The objective during the obturator fabrication (interim or definitive) should be to reduce the weight of the obturator prosthesis. This is because the increased weight of the maxillary obturator is detrimental to the success of the prosthesis due to decreased retention (pulled by gravity), constant rubbing of prosthesis on mucosa and increased patient discomfort. Design and Interventions: Of the many simple baby-steps to ensure enhanced retention of the prosthesis, a simple method to reduce the weight has been described using the subtractive technique of obturator fabrication. Results: Reduced weight of the obturator prosthesis which makes the prosthesis more acceptable to the patient and more successful overall.

The effect of bioelectric and manual impressions on quality of complete dentures and quality of life: A cross over pilot study.

Purpose: To compare the quality of complete dentures and quality of life of participants rehabilitated by using TENS (Transcutaneous electric nerve stimulation) facilitated impression making with manual impressions. Material and methods: Ten completely edentulous participants were enrolled in the crossover, pilot study. Participants were randomized in 2 groups. Five participants in each group were rehabilitated by dentures fabricated with TENS facilitated definitive impression technique (group T) and conventional impression technique (group C). In group T, Bioelectric border molding was done for the participants, that uses electric stimulation of the nerves supplying the muscles. In group C, incremental border molding using modeling plastic impression compound was carried out. Participants in each group used the dentures for 3 months. After 3 months, OHIP-EDENT questionnaire responses were obtained from the participants to observe the oral health related quality of life. A dental specialist recorded denture quality by Kapur scoring criteria. After one month wash period, the treatment was swapped between the groups. OHIP-EDENT scores and Kapur score were recorded for the alternate dentures after 3 months of use. Descriptive analysis was followed by Mann Whitney test to compare the overall scores between group T and group C for OHIP-EDENT, the scores for individual domains of OHIP-EDENT, and Kapur score for denture evaluation (α = 0.05). Results: The overall OHIP-EDENT scores within each domain were less in group T when compared with the scores in group C and Kapur score for group T was more than group C. The difference was statistically significant i.e. P = 0.002 & 0.003 respectively. Conclusions: Less OHIP-EDENT scores in group T imply better perception of quality of life of individuals due to better performance of stomatognathic system. The higher Kapur scores in group T signifies better quality of dentures when TENS was used for definitive impression making.

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.

Comparison of Soft Tissue Volumetric Changes and Pink Esthetics After Immediate Implant Placement with Socket Shield and Conventional Techniques: A Randomized Controlled Trial.

PURPOSE: To compare volumetric changes in buccal soft tissue and pink esthetic scores after immediate implant placement performed with a socket shield technique (SST) or the conventional technique (CT). MATERIALS AND METHODS: This parallel-arm, randomized controlled trial included 22 participants requiring replacement of a single maxillary incisor with an immediate implant. Immediate implants were placed via either the SST or the CT, with patients randomly allocated to one of the two groups. All implants underwent an immediate loading protocol. Definitive crowns were placed 6 months after implant placement. Scans of casts were recorded with a digital white light scanner before implant placement and at the end of 12 months. Volumetric changes to soft tissues on the buccal aspect were assessed by superimposition of the scanned cast. Esthetic evaluation of the soft tissue was done by evaluating the pink esthetic score (PES) before implant placement and 6 and 12 months after implant placement. Statistical analysis of the data was performed using statistical software (Stata 16.0, StataCorp). RESULTS: The mean volumetric change in buccal soft tissues at the end of 12 months in the SST group was -0.1520 ± 0.86 mm, and in the CT group, it was -0.643 ± 0.35 mm. The difference was statistically significant (P = .001). Higher PES was observed in the SST group at all time intervals. The difference was statistically significant at 6 months (P = .001) and 12 months (P = .007). CONCLUSIONS: The results of this study showed less volumetric changes in buccal soft tissues and higher PES when the SST is used rather than the CT.

Comparison of soft tissue volumetric changes and pink aesthetics in immediate implant placement by socket shield and conventional technique: A randomized controlled trial.

PURPOSE: The purpose of this study was to compare soft tissue volumetric changes on buccal aspect and pink aesthetics score in immediate implant placement by socket shield and conventional technique. MATERIAL AND METHODS: This parallel-arm, randomized controlled trial included 22 participants requiring replacement of single maxillary incisor by immediate implant placement. Immediate implants were placed with socket shield technique (SST) and conventional technique (CT) in respective two groups after randomization. All implants were immediately loaded by immediate loading protocol. Definitive crowns were placed 6 months after implant placement. Scans of casts were recorded by using a digital white light scanner before implant placement and at the end of 12 months. Volumetric soft tissue changes on the buccal aspect was assessed by the superimposition of scanned cast. Esthetic evaluation of soft tissue was done by using pink esthetic score (PES) before implant placement, 6 months, and 12 months after implant placement. Statistical analysis of the data was performed using statistical software (Stata 16.0; Stata Corp LLC). RESULTS: The mean soft tissue volumetric change on the buccal aspect at the end of 12 months in the SST group was -0.1520 ±0.86 mm, and in the CT group was -0.643 ±0.35 mm and the difference was statistically significant (P=.001). Higher PES was observed in the SST group when compared to the CT group at all time intervals. The difference was statistically significant at 6 months (P=.001) and 12 months (P=.007). CONCLUSIONS: The results of the study show less volumetric change on the buccal aspect and higher PES in SST when compared to CT. Int J Prosthodont 2023. doi: 10.11607/ijp.8063.

Osteogenic markers in peri-implant crevicular fluid in immediate and delayed-loaded dental implants: A randomized controlled trial.

INTRODUCTION: The study evaluates the levels of matrix metalloprotease-8 (MMP-8), and Cathepsin-K (CatK) in peri-implant crevicular fluid (PICF) among patients with immediate loaded (IL) and delayed-loaded (DL) implants at different time points to know the inflammation and osteogenic status. METHODS: The study population consisted of two groups (n = 25, each group) with a mean age of 28.7 ± 3.5 years, and PICF was collected. MMP-8 and CatK levels were quantified through ELISA. RESULTS: We observed the concentrations of inflammatory markers (MMP-8 and CatK) at three time points in the IL and DL groups. The mean concentration of MMP-8 in the IL group was 9468 ± 1230 pg/mL, 5547 ± 1088 pg/mL, and 7248 ± 1396 pg/mL at 2 weeks, 3 months, and 12 months, respectively; while in the DL group was 10 816 ± 779.7 pg/mL, 9531 ± 1245 pg/mL, and 9132 ± 1265 pg/mL at 2 weeks, 3 and 12 months, respectively. The mean concentration of Cat-K in the IL group was observed at 422.1 ± 36.46 pg/mL, 242.9 ± 25.87 pg/mL, and 469 ± 75.38 pg/mL at 2 weeks, 3, and 12 months, whereas in the DL group was 654.6 ± 152.9 pg/mL, 314.7 ± 28.29 pg/mL, and 539.8 ± 115.1 pg/mL at 2 weeks, 3 months and 12 months, respectively. CONCLUSION: In this study, the levels of CatK and MMP-8 levels decline at 12 months in both groups, and the IL group shows lower values compared to the DL group; however, no significant changes were observed after analyses were adjusted for multiple comparisons (p > 0.025). Therefore, there is not much difference observed in the inflammation process between immediate and delayed loading. (Clinical trial identifier: CTRI/2017/09/009668).

Acrylic cranial implant: an alternative vector in management of cranial defect.

In a pediatric patient with cranial defect, in order to replace the missing portion of the cranium, an acrylic cranial implant was fabricated prior to the surgical procedure. The primary aim was to fabricate this cranial implant prior to the surgical procedure and with optimum fit. A customized hand-sculpted acrylic cranial implant fabricated by lost wax technique was made prior to the surgery and with adequate precision.The prefabricated cranial implant was used by neurosurgeons on the patient in order to restore the continuity of bone (by the acrylic cranioplast) over the cranial defect, improving the aesthetics and more importantly providing protection to the vital neural tissue.Though with recent advancements (like computer-aided design and manufacturing, and rapid prototyping), rapidity and precision can be achieved in the fabrication of cranial prosthesis, yet most of the apparatus may not be amenable in every setup and may not be affordable by all patients. A simple, operator-friendly technique which acquires satisfactory precision has been described for a patient much in need. Optimal postoperatory results were attained.