All-on-four concept and immediate loading for simultaneous rehabilitation of the atrophic maxilla and mandible with conventional and zygomatic implants

We report the simultaneous rehabilitation of an edentulous patient with a hybrid (zygomatic and conventional implants) all-on-four implant-supported prosthesis for the maxilla and a standard (conventional implants) all-on-four implant-supported prosthesis for the mandible. The transfer impression was made with a multifunctional guide and the upper and lower prostheses were placed 24 h postoperatively. Clinical and radiographic examinations showed no infection or bony resorption 2 years later. Simultaneous maxillary and mandibular rehabilitation with all-on-four immediate loading is a viable, fast and effective option for edentulous patients. (C) 2009 Published by Elsevier Ltd on behalf of The British Association of Oral and Maxillofacial Surgeons.

Bone healing pattern in surgically created circumferential defects around submerged implants: an experimental study in dog

Objective: To describe the healing of marginal defects below or above 1 mm of dimension around submerged implants in a dog model.Material and methods: In 12 Labrador dogs, all mandibular premolars and first molars were extracted bilaterally. After 3 months of healing, full-thickness flaps were elevated in the edentulous region of the right side of the mandible. Two recipient sites were prepared and the marginal 5mm were widened to such an extent to obtain, after implant installation, a marginal gap of 0.5mm at the mesial site (small defect) and of 1.25mm at the distal site (large defect). Titanium healing caps were affixed to the implants and the flaps were sutured allowing a fully submerged healing. The experimental procedures were subsequently performed in the left side of the mandible. The timing of the experiments and sacrifices were planned in such a way to obtain biopsies representing the healing after 5, 10, 20 and 30 days. Ground sections were prepared and histomorphometrically analyzed.Results: The filling of the defect with newly formed bone was incomplete after 1 month of healing in all specimens. Bone formation occurred from the base and the lateral walls of the defects. A larger volume of new bone was formed in the large compared with the small defects. Most of the new bone at the large defect was formed between the 10- and the 20-day period of healing. After 1 month of healing, the outline of the newly formed bone was, however, located at a similar distance from the implant surface (about 0.4mm) at both defect types. Only minor newly formed bone in contact with the implant, starting from the base of the defects, was seen at the large defects (about 0.8mm) while a larger amount was detected at the small defects (about 2.2 mm).Conclusion: Marginal defects around titanium implants appeared to regenerate in 20-30 days by means of a distance osteogenesis. The bone fill of the defects was, however, incomplete after 1 month.

Expectations and final evaluation of complete dentures by patients, dentist and dental technician

There is a poor association between the dentist's evaluation of denture quality and patients' satisfaction with their dentures. Possible differences between dental professionals and patients' expectations might help explain differences in outcome evaluations. This study compared scores given by a dentist, a dental technician and patients for their expectations before and their final evaluation after complete dentures treatment. Twenty completely edentulous patients, a prosthodontist and a dental technician provided scores for the expected aesthetic and functional results of their dentures based on a visual analogue scale at baseline. Post-treatment completion ratings were given after adjustments, by dentist and patients. The dental technician provided post-treatment completion ratings after completing the dentures. The patients had higher expectations than the dental technician and the dentist perceived for both aesthetic and function (P < 0.001). The patients also presented higher post-treatment completion ratings than the dental professionals perceived for final aesthetics (P = 0.016, Kendall's W = 0.207). and function (P = 0.002, Kendall's W = 0.303). Only the dentist presented a statistically significant difference between expectations (lower) and final (higher) outcomes for aesthetics (P = 0.017) and function (P = 0.003). There was no correlation between expectations and post-treatment completion ratings according to the patients' age. There was also no correlation between the patients' gender and expectation scores. Patients presented higher expectations regarding their dentures than dental professionals. The dentist believed that dentures would bring fewer benefits than patients did, but his perception of denture benefits post-treatment was significantly higher than his expectations.

Squamous cell carcinoma in a residual mandibular cyst

Described is a case of squamous-cell carcinoma arising in a residual cyst in a 60-year-old edentulous woman. The clinical and radiographic diagnosis was residual cyst, and the treatment employed was conservative surgical enucleation. The cause of these changes is unknown. Theoretically, the inflammatory reaction may have been a predisposing factor.

Determinação da relação central. Estudo sobre as posições laterais da mandíbula, em relação à linha mediana facial, em função de dois métodos para esta determinação.

The authors studied the lateral positional desviations of the mandible, in relation to the facial median line in 30 (thirty) full edentulous patients, with the purpose to verify the influence of the unstrained guided (chinpoint guidance) and deglutition methods for the determination of centric relation. According the results obtained they conclude that the unstrained guided method produced a mandibular lateral desviation with a mean value of the 0.752 mm and in the deglutition method the mean value observed was 1.109 mm. The statistical analysis of the results revealed for the unstrained guided method a proportion of the points to the right and left of the median line not statistically significant, while for the deglutition method the difference was statistically significant at a level of 5%.

The structure of the human temporomandibular joint disc: A scanning electron microscopy study

The articular disc of the temporomandibular joint was studied in fetuses (16 to 39 weeks of intrauterine life), infants (up to 4 months of age), dentulous adults (aged 30 to 39 years), and completely edentulous adults (aged 60 to 69 years) by scanning electron microscopy. The constituent bundles of collagen fibers were stratified and were oriented anteroposteriorly, laterolaterally, and obliquely in the middle portion of the disc. A ring of laterolateral bundles constituted the main feature of the thick posterior portion. In the anterior portion of the disc, the fibers were anteroposteriorly and obliquely oriented. On the superior and inferior surfaces of the disc, a thin layer of perpendicularly arranged collagen fibers covered the underlying, thick, laterolateral oriented collagen fibers.

Tensile bond strengths of hard chairside reline resins as influenced by water storage

Due to gradual resorption of the edentulous ridge bone, removable prostheses often require denture base relines to improve fit and stability. This research evaluated the bond strength between one heat-cured acrylic resin (Lucitone 550®) and two hard chairside reline resins, after two different periods of storage in water (50 h and 30 days). The bond strength was evaluated using a tensile test. The mode of failure, adhesive or cohesive, was also recorded. The results submitted to the Kruskal-Wallis test indicated that the highest tensile strengths were achieved with intact Lucitone 550® denture base resin in both periods of storage in water. After 50 h of storage in water, Duraliner II® reline material exhibited the highest bond strength to the denture base resin. After 30 days of storage in water, Duraliner II® reline resin demonstrated a significant reduction in adhesion, showing lower tensile bond strength than Kooliner® material. Both hard chairside reline materials failed adhesively across Lucitone 550® denture base resin, in both periods of time. © 1999 Blackwell Science Ltd.

Avaliacao das condicoes de saude bucal dos idosos em um municipio brasileiro

This study assessed the oral health of individuals 60 years or older in the city of Araraquara, Sao Paulo, Brazil, in 1998. Of the 194 people who participated in the study, 91 of them were institutionalized and had an average age of 73.6 years, and 103 were not institutionalized and had an average age of 69.3 years. The study participants were examined by a previously trained oral surgeon who determined the prevalence of the most common oral health problems. The results revealed a large number of edentulous individuals (72% of those institutionalized and 60% of the noninstitutionalized participants) and many persons with extracted teeth (93% and 90%, respectively), as well as a high frequency of periodontal pockets (57% and 75%, respectively) and of inadequate dentures (80% and 61%, respectively). Our results show reduced quality of life for a large proportion of these older individuals, and also indicate that public health services should pay greater attention to this population group.

Microbiologic and radiographic analysis of ligature-induced peri-implantitis with different dental implant surfaces

Purpose: The goal of this study was to evaluate microbiota and radiographic peri-implant bone loss associated with ligature-induced peri-implantitis. Materials and Methods: Thirty-six dental implants with 4 different surfaces (9 commercially pure titanium, 9 titanium plasma-sprayed, 9 hydroxyapatite, and 9 acid-etched) were placed in the edentulous mandibles of 6 dogs. After 3 months with optimal plaque control, abutment connection was performed. On days 0, 20, 40, and 60 after placement of cotton ligatures, both microbiologic samples and periapical radiographs were obtained. The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Campylobacter spp, Capnocytophaga spp, Fusobacterium spp, beta-hemolytic Streptococcus, and Candida spp were evaluated culturally. Results: P intermedia/nigrescens was detected in 13.89% of implants at baseline and 100% of implants at other periods. P gingivalis was not detected at baseline, but after 20 and 40 days it was detected in 33.34% of implants and at 60 days it was detected in 29.03% of dental implants. Fusobacterium spp was detected in all periods. Streptococci were detected in 16.67% of implants at baseline and in 83.34%, 72.22%, and 77.42% of implants at 20, 40, and 60 days, respectively. Campylobacter spp and Candida spp were detected in low proportions. The total viable count analysis showed no significant differences among surfaces (P = .831), although a significant difference was observed after ligature placement (P < .0014). However, there was no significant qualitative difference, in spite of the difference among the periods. The peri-implant bone loss was not significantly different between all the dental implant surfaces (P = .908). Discussion and Conclusions: These data suggest that with ligature-induced peri-implantitis, both time and periodontal pathogens affect all surfaces equally after 60 days.

Diagnostic agreement of conventional and inverted scanned panoramic radiographs in the detection of the mandibular canal and the mental foramen.

The aim of this study was to evaluate the diagnostic agreement of conventional panoramic radiographs and their inverted scanned images in the detection of the mandibular canal and mental foramen. A total of 77 panoramic radiographs obtained from the files of totally edentulous patients were used. Digitization was done by means of a scanner with brightness and contrast adjustment, as well as image inversion. The extension of mandibular canal was divided into anterior, middle, and posterior regions, and the presence of a radiopaque line that characterized the mandibular canal was classified according to a 5-point confidence scale. The mental foramen was classified in 4 types: continuous, separated, diffuse, and unidentified. Both conventional and inverted scanned panoramic radiographs were evaluated by 3 calibrated implantologists at 2 distinct moments with a minimum interval of 10 days between them. Intraexaminer agreement was evaluated by Kappa statistics by point and by 95% confidence interval. Because the intraexaminer level of agreement was low, interexaminer agreements could not be carried out. The results showed a substantial (in 2 situations), moderate (in 16 situations), and fair (in 18 situations) intraexaminer agreement for mandibular canal and a substantial (in 1 situation), fair (in 1 situation), and moderate (in 10 situations) intraeaminer agreement for mental foramen. There were no statistically significant differences in most instances. In conclusion, the diagnostic agreement of conventional and inverted scanned panoramic radiographs for detection of mandibular canal and mental foramen was low.

Relation between speaking space of the /s/ sound and freeway space in dentate and edentate subjects.

The purpose of this study is to assess the relation between the speaking space of the /s/ sound and the freeway space in two subject groups. One group had natural dentition (Group I, n = 61) and the other comprised complete denture wearers (Group II, n = 33). The analysis was done by means of a jaw-tracking device (K6-I Diagnostic System, Myotronics Research Inc., Seattle, WA, USA). Freeway space was determined by asking the subjects to occlude from the postural rest position. Speaking space of /s/ was measured during the pronunciation of the word seis and comprised the mean distance from the /s/ speaking position to maximal intercuspation. A weak correlation was found between the speaking space of /s/ and the freeway space in Group I (r = 0.41, p < 0.01), but in Group II, the correlation was stronger (r = 0.75, p < 0.01). The speaking space of /s/ and freeway space were different in Group I, but statistically similar in Group II (paired t-test, alpha = 0.05). It can be suggested that anatomic changes following prosthetic procedures caused a functional adaptation which resulted in more similar values for the speaking space of /s/ and the freeway space.

Cocaine associated with onlay bone graft failure: A clinical and histologic report

This patient report presents an unusual onlay bone graft failure following local cocaine application. Three months after the bone grafting procedure performed in the anterior maxilla for bone volume augmentation, the bone graft was totally exposed in the oral cavity as a result of the rubbing of cocaine on the gingival tissue that covered the bone graft. A histologic view of the removed bone fragment presented not only an area of necrosis but also ample spaces filled with necrosis material and resorption areas. Dental practitioners need to be aware of this phenomenon because such patients often do not report the use of drugs, particularly cocaine. Copyright © 2005 by Lippincott Williams & Wilkins.

Prosthetic rehabilitation of a bone defect with a teeth-implant supported, removable partial denture

The use of teeth-implant, mucosa-supported removable dentures for rehabilitation of partially edentulous patients involves highly complex biomechanical aspects. This type of prosthesis associates 3 kinds of support that react differently to the functional and parafunctional forces developed in the oral cavity. Although the construction of removable partial dentures may seem paradoxical when osseointegrated implants are placed, in some cases, this option is an excellent alternative to solve difficulties related to the anatomic, biologic, psychomotor, and financial conditions of the patient. This article reports on a case in which a teeth-implant, mucosa-supported removable partial denture was the option of choice for a patient with financial and anatomic limitations, having a large structural loss of the residual alveolar ridge caused by trauma by a gunshot injury at the mandible. The 5-year follow-up did not reveal any type of biomechanical or functional problem. Copyright © 2006 by Lippincott Williams and Wilkins.

Nasal width as a guide for the selection of maxillary complete denture anterior teeth in four racial groups

Purpose: Selecting artificial teeth for edentulous patients is difficult when pre-extraction records are not available. Various guidelines have been suggested for determining the width of the maxillary anterior denture teeth. This study was undertaken to evaluate the use of the nasal width as a guide for the selection of proper width maxillary anterior denture teeth in four racial groups of the Brazilian population. Materials and Methods: One hundred and sixty subjects (40 Whites, 40 Mulattos, 40 Blacks, and 40 Asians) were selected. Using a sliding caliper, the nasal width and the intercanine distance were measured. The Pearson product-moment correlation coefficient was used to determine the relationship between the above measurements. A prediction was made of the percentage of subjects of the White, Mulatto, Black, and Asian populations in which the selection error due to the clinical application of the method of the nasal width would be within 0 to 2 mm, within 2 to 4 mm, and greater than 4 mm. Results: The four racial groups showed a weak correlation between the intercanine distance and the nasal width. In 39.7% of the White, 55.7% of the Mulatto, 81.9% of the Black, and 48.2% of the Asian populations, errors greater than 4 mm would be present with the use of the nasal width. Conclusions: The correlation found between the intercanine distance and the nasal width was not high enough to be used as a predictive factor. The relationship between natural tooth width and artificial tooth width as predicted by the nasal width showed that the nasal width method is not accurate for all the studied groups. Copyright © 2006 by The American College of Prosthodontists.

Complete denture masticatory efficiency: a literature review

The restoration of masticatory function and esthetics is an important aim in dentistry mainly when patients present with extensive tooth loss. The aim of mastication is to reduce food size to produce a homogeneous bolus appropriate to be swallowed. For edentulous patients, chewing efficiency is reduced because dental arches are replaced by artificial teeth. The aim of this study is to present factors related to chewing efficiency for the edentulous patient.