Staged Reconstruction (Delayed-Immediate) of the Maxillectomy Defect Using CAD/CAM Technology

Background Computer-aided design/computer-aided manufacturing (CAD/CAM) technology has become increasingly popular for free fibula reconstruction of the mandible. The same technology, however, has not been widely utilized in immediate complex midface reconstruction utilizing free fibula flaps. Maxillary defects are difficult to precisely predict or produce matched cutting guides for after the ablative surgery. We present a protocol for “delayed-immediate” two-stage reconstruction for complex mid-facial defects, by delaying lymph node neck dissection and using CAD/CAM technology for delayed bony reconstruction.

Methods Stage 1 includes the extirpative surgery, placement of a temporary obturator, and an immediate post-excision fine cut computed tomography (CT) of the defect that is used for CAD/CAM planning. The time interval between stages is used for virtual surgical planning (VSP) and provides an opportunity for the final pathologic margins to be evaluated. At stage 2, definitive reconstruction is performed in conjunction with the delayed neck dissection. Briefly delaying the neck dissection until stage 2 allows for recipient vessel dissection and microsurgical anastomoses to safely occur in a surgically naïve neck.

Conclusion A two-stage delayed-immediate reconstruction of complex mid-face defects can be safely and effectively performed. This protocol takes advantage of advancing CAD/CAM technology, provides an opportunity to evaluate final margins, and avoids recipient vessel dissection and microsurgery in previously operated or irradiated necks.

A Contemporary Framework and Suprastructure Ceramic Design for Posterior Implant Fixed Partial Denture

Bone and soft tissue deformities in long-standing partial edentulism are commonly treated with implant therapy. The various ceramic restorative systems available and digital technology allow for customization of design and material selection. A substructure design that mimics tooth preparation in a custom zirconia framework with a lithium disilicate suprastructure is presented as an effort to address the functional and esthetic challenges posed by long-standing posterior partial edentulism. The aim is to present several contemporary elements of design to address the functional, esthetic, and maintenance needs.

Correction of bone and softtissue deformity of the single implant in the aesthetic zone: a case treated with alveolar ridge preservation, modified roll technique and a digitally coded healing abutment

The correction of soft tissue deformity and aesthetic rehabilitation of a single implant in the aesthetic zone with a combination of periodontal and prosthodontic approaches is described. Soft tissue deformity was corrected resulting in significant soft tissue volume increase and eliminated the need for prosthetic gingival replacement. A two stage implant placement protocol, ridge preservation and a soft tissue augmentation flap design preserved epithelium attachment to the connective tissues. Use of a digitally coded healing abutment preserved the newly established soft tissue volume, allowed impression making without implant component removal, and minimized trauma to the newly established soft tissue architecture.

Correction of esthetic and biomechanical outcomes after maxillary anterior single dental implant fracture: a case report

Rehabilitation of the single anterior tooth in the esthetic region after a dental implant fracture requires management of contributing biomechanical and/or biological etiologic factors. The multidisciplinary treatment of a fractured maxillary anterior single dental implant with a staged, combined surgical and prosthetic approach is discussed. Alleviation of several, but not all, risk factors eliminated the need for replacement of gingiva with pink porcelain and maintained a stable post implant host complex.

Evaluation of fracture resistance in aqueous environment under dynamic loading of lithium disilicate restorative systems for posterior applications. Part 2

PURPOSE

The goals of part 2 of the study presented here were 1) to assess whether there is a difference in failure mode of different thicknesses (2.0, 1.5, 1.0, and 0.5 mm) of anatomically standardized full contour monolithic lithium disilicate restorations for posterior teeth, and 2) to assess if there is a difference among various crown thicknesses when these restorations are subjected to dynamic load forces common for posterior teeth.

MATERIALS AND METHODS

Four groups (n = 10), each with a different thickness of anatomically appropriate all-ceramic crowns, were to be tested as established from the statistical analysis of the preliminary phase. Group 1: 2.0 mm; group 2: 1.5 mm; group 3: 1.0 mm; group 4: 0.5 mm. The specimens were adhesively luted to the corresponding die, and underwent dynamic cyclic loading (380 to 390 N) completely submerged in an aqueous environment until a failure was noted by graphic recording and continuous monitoring.

RESULTS

There was a statistically significant difference of the fatigue cycles to failure among four groups (p < 0.001; Kruskal-Wallis test). The mean number of cycles to fail for 2.0 mm specimens was 17 times more than the mean number of cycles to fail for 1.0 mm specimens and 1.5 times more than the mean number of cycles to fail for 1.5 mm specimens. The 0.5 mm specimens failed with one cycle of loading. A qualitative characteristic noted among the 2.0 mm specimens was wear of the area of indenter contact followed by shearing of the material and/or crack propagation.

CONCLUSION

Based on the findings of this study, it may be reasonable to consider a crown thickness of 1.5 mm or greater for clinical applications of milled monolithic lithium disilicate crowns for posterior single teeth.

A tooth-stabilized surgical template for alveolectomy

The supraeruption of teeth and bone in patients with long-standing partial edentulism often results in compromised interarch distance. A method is presented for the fabrication and predictable use of a tooth-stabilized surgical template for alveolectomy in instances where teeth are present.

Rehabilitation of medically complex ectodermal dysplasia with novel surgical and prosthodontic protocols

The functional and aesthetic needs of a 17-year-old patient afflicted with ectodermal dysplasia, chronic long-term immunosuppression, cleft palate, velopharyngeal insufficiency, hypernasality, maxillary hypoplasia, and oligodontia were met with a multidisciplinary team approach. Predictable functional and aesthetic outcomes were obtained with a combination of injection augmentation of the soft palate and nasopharynx and rigid fixation maxillary external distraction with immediate placement and immediate load protocols. No biological or prosthetic complications were noted after definitive rehabilitation with a mandibular implant-retained fixed prosthesis and a maxillary implant-retained detachable prosthesis.

Virtual surgical planning for treatment of severe mandibular retrognathia with collapsed occlusion using contemporary surgical and prosthodontic protocols

PURPOSE

To meet functional and esthetic needs in an older adult for treatment of complex skeletal and dentoalveolar deformities using contemporary surgical and prosthodontic protocols.

METHODS

An older adult with dentoalveolar complex and skeletal deformity (mandibular retrognathia) was treated by a combination of virtual planning and current surgical and prosthodontic protocols. Treatment planning steps and sequencing are presented.

RESULTS

Skeletal, soft tissue, and dental harmonies were attained without biological or mechanical complications. Definitive oral rehabilitation was completed with a maxillary complete denture and a mandibular metal ceramic fixed implant-retained prosthesis.

CONCLUSIONS

A surgical and prosthodontic team approach in combination with technologic advances can predictably optimize esthetic and functional outcomes for patients with complex skeletal and dentoalveolar deformities.

Development of stable peri-implant soft tissue and mentolabial sulcus depth with an implant-retained soft tissue conformer after osteocutaneous flap reconstruction

Excessive soft tissue bulk, movement, chronic inflammation, and hypertrophy in periimplant areas pose challenges for long-term management of peri-implant soft tissues surrounding osteocutaneous flap reconstructions. A case history report is presented on the predictable establishment of stable peri-implant soft tissue and improved mentolabial sulcus depth in a patient treated for high-grade osteosarcoma of the mandible. Following surgical resection, reconstruction with osteocutaneous fibula free flap, and endosseous implant placement, a combined surgical and prosthetic approach was used through a lip switch vestibuloplasty and an implant-retained soft tissue conformer.

Preference changes of adult outpatients for giving saliva, urine and blood for clinical testing after actual sample collection

PURPOSE

Patients' preferences of the type of sample collections for clinical testing are currently unknown. The aims of this study were: (1) to assess patients' preferences of three types of samples for clinical testing (saliva, urine and blood) both before and after collection and (2) to assess whether prior experiences with collection of saliva impacted patients responses.

METHODS

Adult outpatients underwent collection of one sample each of saliva, urine and blood. Patients' perceptions of comfort, convenience and easiness were assessed in pre-collection and post-collection questionnaires.

RESULTS

Post-collection, patients' endorsement of saliva as being the "most comfortable" and "most convenient" significantly declined (pre vs. post, 61.5% vs. 37.5% and 73.1% vs. 42.3%). However, saliva was still endorsed as the "most convenient" post-collection (compared to urine 33.7% and blood 24.0%). Although not statistically significant, the proportion of patients who changed their response in terms of what sample was "easiest to collect at home" was considerably higher in the group with vs. without prior experience giving saliva (54.6% vs. 32.6%, p=0.19 Fisher's exact test).

CONCLUSIONS

Overall, saliva remained as the most highly preferred sample to donate despite a decline in patients' preferences of saliva donation after sample collection. The results of the study are promising for future widespread patient acceptance of saliva as a diagnostic fluid.

Comparison of two different veneer preparation designs in vital teeth

OBJECTIVE

To compare the clinical performance of two different veneer preparation designs (overlap and nonoverlap) on anterior veneer restorations in vital teeth in a retrospective clinical study.

METHOD AND MATERIALS

In this study, 292 anterior all-ceramic veneer restorations in vital teeth were clinically examined in 74 patients. The preparation designs were categorized by the amount of tooth reduction on the final casts, with 245 in the overlap and 47 nonoverlap group.

RESULTS

After a mean ± SD observation time of 124.25 ± 60.61 months, 20 failures occurred. All failures occurred in the overlap design. Restorations with nonoverlap preparation designs showed significantly fewer failures than restorations with overlap preparation design (P = .018, log-rank).

CONCLUSION

Based on the findings of this study, whenever feasible, a preparation design without incisal overlap is recommended, especially in vital teeth..

Dental students' perceptions of dental specialties and factors influencing specialty and career choices

The goals of this study were to 1) evaluate dental students' perceptions of dental specialties, 2) identify factors that play an important role in students' decision to pursue specialty training or career choices, and 3) establish a baseline of students' perceptions of the dental fields with the best future in terms of salary, personal and patient quality of life, and overall impact on the dental profession. Surveys were distributed to 494 students at the University of Pennsylvania School of Dental Medicine. Data were collected from 380 traditional four-year students and thirty advanced standing students. Chi-square tests, multivariate analysis, and logistic regressions were used to determine associations and independent contributions of student demographics to their perceptions of dental specialties and factors influencing specialty training or career choices. Debt was a statistically significant factor (p<0.001) in choosing specialty training or career independent of gender, age, or class year. Enjoyment of providing care in a specialty or field was identified as the single most important factor in choosing a specialty career. Half of the respondents had decided not to specialize. Pursuing postdoctoral general dentistry training and private practice in general dentistry were the most commonly reported plans after completion of dental school. Suggestions are made for ways to inform students about specialty training.