Crestal sinus lift using an implant with an internal L-shaped channel: 1-year after loading results from a prospective cohort study

PURPOSE

To evaluate the clinical and radiographic outcomes of a one-stage crestal sinus elevation procedure using a self-tapping endosseous implant system (iRaise, Maxillent, Herzliya, Israel) developed for sinus augmentation, 1 year after loading.

MATERIALS AND METHODS

Patients needing restoration in the posterior maxilla with a residual alveolar crest of 3 to 8 mm in height and 5 mm in width distal to the canine as measured on CBCT scan were treated using the iRaise sinus lift system. Outcome measures were: implant and prosthetic failures, any complications, increased bone height (iBH), marginal bone loss (MBL), implant stability quotient (ISQ), radiographic tissue remodelling patterns using the sinus grafting remodelling index (SGRI), volumetric measurements of sinus graft, patient self-reported post-surgical swelling, consumption of pain medication and histological analysis.

RESULTS

A total of 30 consecutive participants with a mean age of 54.2 ± 9.4 years underwent a transcrestal elevation of the sinus membrane, insertion of bone graft, and implant placement. A total of 50 implants were placed (30 iRaise system implants and 20 adjunctive iSure implants, Maxillent). The mean follow-up was 15.8 ± 2.1 months after implant loading. One patient dropped out at the 1-year after loading follow-up examination. No implants and no prostheses failed during the entire follow-up. One patient experienced a small membrane tear. Before implant insertion, the mean residual alveolar ridge height was 4.64 ± 0.86 mm (range: 3.4-6.4 mm; 95% CI: 4.39-5.01 mm). One year after loading, the bone height was 16.86 ± 3.13 mm (95% CI 15.83-18.07 mm). At the 1-year after loading follow-up, the mean MBL was 0.19 ± 1.05 mm (95% CI 0.02-0.78 mm). The mean ISQ at implant placement was 65.2 ± 5.4 (95% CI 63.6-67.4) and increased during the healing period reaching the mean value of 73.6 ± 3.7 (95% CI 73.1-75.9; range 62-79). The difference was statistically significant (8.4 ± 5.3; 95% CI 5.9-39.7; P = 0.0000). One year after loading, SGRI score was evaluated in 23 implants. Overall, the mean SGRI value was 2.29 ± 2.41 mm (95% CI 1.22-2.98 mm). Bone volume at implant placement was 2.41 ± 0.25 CC (95% CI 2.22-2.48 CC). During the 6-month, submerged healing period, a slight bone contraction of 11.3% were observed. (2.13 ± 0.24 CC;95% CI 2.02-2.26; difference = 0.27 ± 0.25 CC; 95% CI 0.10-0.36; P = 0.0011). At the first year post-loading period, the bone graft remained stable (2.11 ± 0.22 CC; 95% CI 2.02-2.24). The difference was not statistically significant (0.02 ± 0.07 CC; 95% CI 0.01-0.04; P = 0.2166). From the patient's point of view, the mean pain value was 0.52 ± 0.74 (range 0-3); mean swelling value was 0.27 ± 0.52 (range 0-2); and the mean consumption of analgesic was 0.87 ± 4.94 tablets (range 0-4) 3 days after surgery. Morphological and histomorphometric analyses showed that all the samples had a normal structure without inflammatory infiltrate, six months after healing. The following fractions (%) were found: bone (immature bone + mature bone): 44.07 ± 4.91; residual biomaterial: 23.98 ± 2.64; medullary spaces: 31.95 ± 3.16.

CONCLUSIONS

Sinus floor augmentation can be successfully accomplished with a transcrestal approach using a dedicated implant system. A physiologic contraction of 11.3% of the original volume of the bone graft was experienced during the first 6 months of healing; afterwards, no additional graft volume reduction was observed. Long-term clinical studies are needed to confirm these preliminary results.

Soft tissue healing in alveolar socket preservation technique: histologic evaluations

After tooth extraction, 14 alveolar sockets were grafted with porous bovine bone mineral particles and covered with non-cross-linked collagen membrane (test group), and 14 alveolar sockets were left uncovered. At 5 and 12 weeks, microvascular density (MVD), collagen content, and amount of lymphocytes (Lym) T and B were analyzed in soft tissue. At 5 weeks, MVD was significantly lower and Lym T was significantly higher in tests than in controls (P < .05). At 12 weeks no differences were found. Placement of resorbable membrane seems to induce an initial and transient modification of the normal wound healing process of the soft tissue.

Histologic and immunohistochemical description of early healing at marginal defects around implants

This study reports on the histologic characteristics of the early phases of implant osseointegration, focusing on osteopontin concentrations in the coronal area of implants placed with marginal defects and in control sites without defect preparation. In the mandibular right area of 12 dogs, two recipient sites were prepared and the margins were widened to obtain a gap of 0.5 mm at one site (small defect) and 1.25 mm at another site (large defect). Implants were placed and allowed a fully submerged healing. The procedure was subsequently performed in the left side in such a way as to obtain healing times of 5, 10, 20, and 30 days. Paraffin sections were stained with osteopontin antibodies and analyzed. At control implants, scarcely organized collagen fibers were observed in the space between the pristine bone and implant and were quickly replaced by mineralized tissue. In the small and large defects, the collagen fibers were organized in a layer that ran parallel to the implant at day 10 and became denser and thicker with time. Osteopontin was evenly distributed in the peri-implant tissue at control implants, while it was mainly located in the collagen bundle section around the implants placed in the defects.

Histologic and Radiographic Comparison of Bone Scraper and Trephine Bur for Autologous Bone Harvesting in Maxillary Sinus Augmentation

PURPOSE

The aims of this study were to investigate the best two of five common methods of collecting autologous bone (preliminary study [PS]) and to test clinically the effects of autografts harvested using a trephine bur or bone scraper for sinus augmentation surgery (main study [MS]).

MATERIALS AND METHODS

In the PS, five autograft samples from five patients (n = 25) were harvested with a bone scraper, round bur, piezoelectric device, implant bur, and trephine bur and were processed for histomorphometric analysis. In the MS, sinus augmentation was performed on 20 patients using bovine-derived bone substitute and autograft collected with a trephine bur (group A, n = 10) or collected with a bone scraper (group B, n = 10). Narrow implants were also placed. At 6 months, changes in graft volume were evaluated with cone beam computed tomography. The amounts of regenerated bone, residual graft, and osseointegration of the implants were assessed histologically.

RESULTS

In the PS, the trephine bur and bone scraper harvested bone chips that were medium to large and more vital than those obtained with the other tools. In the MS, no significant differences were seen between groups in terms of the amount of residual biomaterial, regenerated bone, change in graft volume, and osseointegration.

CONCLUSION

Biologic differences between these two bone particulates may not influence regeneration and implant osseointegration in sinus augmentation when mixed with xenograft bone.

Abnormal Variations in the Facial Soft Tissues of Individuals With Down Syndrome: Sudan Versus Italy

OBJECTIVE

To provide quantitative information about the facial soft tissue of Italian and Northern Sudanese subjects with Down syndrome by using summary anthropometric measurements.

DESIGN, SETTING, AND PATIENTS

The three-dimensional coordinates of soft tissue facial landmarks were obtained using a computerized digitizer in 54 Italian subjects with Down syndrome (20 females and 34 males, 13 to 52 years), in 64 Northern Sudanese subjects with Down syndrome (18 females and 46 males, 5 to 34 years), and in 578 Italian and 653 Northern Sudanese reference subjects, matched for sex and age. From the landmarks, 16 facial dimensions were calculated. Data from subjects with Down syndrome were compared with those collected from control individuals by computing z scores. Two summary anthropometric measurements for quantifying craniofacial variations were obtained: the mean z score (an index of overall facial size) and its standard deviation, the craniofacial variability index (an index of facial harmony).

RESULTS

In subjects with Down syndrome, facial size was significantly smaller and craniofacial variability was significantly greater than in typically developed individuals; 93% of Italian and 81% of Northern Sudanese subjects with Down syndrome had one or both values outside the normal interval. Overall, Italian subjects with Down syndrome differed more from the norm than did those from Northern Sudan. In the Northern Sudanese subjects, the mean z scores and the craniofacial variability index were significantly influenced by age: Older Northern Sudanese subjects with Down syndrome had smaller mean z scores and craniofacial variability index values than younger subjects.

CONCLUSIONS

The two ethnic groups had different alterations in their soft tissue facial dimensions that were partially influenced by age.

Human palatal and tuberosity mucosa as donor sites for ridge augmentation

Since different clinical outcomes of periodontal bilaminar surgeries using the palate or the maxillary tuberosity as connective tissue (CT) donor sites have been observed, tissues grafted with CT from the palate or the tuberosity 1 year after surgical procedures for ridge augmentation were compared with nongrafted tissues by using morphologic and molecular methods. Collagen content and matrix metalloproteinases 1 and 2 expression were similar in tissues and cultured fibroblasts from the palate and tuberosity, although with interindividual differences. In contrast, differences in collagen cross-linking and maturation in the tuberosity fibroblasts were observed, suggesting a possible role in determining hyperplastic responses in some patients.

Quantitative Analysis of the Variability of Unilateral Chewing Movements in Young Adults

Kinesiography can be used as a diagnostic tool in a dental clinic context. In the current study, a kinesiograph was used to detect and record the three-dimensional motion of the mandibular mid-incisor point during unilateral chewing as a function of time. The aim of the study was to quantify the within-subject short-term reproducibility of the kinesiographic recordings in normal, healthy subjects. Ten seconds of unilateral (right and left) gum chewing were recorded in 20 control subjects using computerized kinesiography. Each subject performed 18 chewing sequences (three repetitions x three sessions x two sides). Chewing cycle duration, volume, standardized depth and width, and the number of reversed cycles were calculated. Intraclass correlation coefficients (two-way random effects analysis of variance with interactions) and paired t-tests were used to compare sessions. For each subject and side, chewing variability was expressed as the coefficient of variation (percentage ratio of standard deviation to mean) of each variable. Mean left and right side mastications were computed over all sessions and subjects. For all the analyzed variables, larger variations between subjects (analysis of variance, p < 0.001) than between sessions were found, with intraclass correlation coefficients ranging between 0.432 (left side cycle duration) and 0.989 (right side standardized width). No systematic errors between the three measurement sessions were found for cycle volume and shape (paired t, p > 0.05). The highest between subjects/ between sessions variance ratios (up to 223.28) were found for cycle duration and shape. In all subjects, chewing cycle volume was very variable, with mean coefficients of variation up to 47% (left side in females). Cycle duration and standardized depth and width were more reproducible, with mean coefficients of variation up to 10% (duration), 14% (standardized width), and 18% (standardized depth). The spatial characteristics of gum chewing cycles had a large within-subject variability. The temporal and size-standardized (shape) characteristics were more consistent within subject. The results should allow selection of a set of relatively more consistent variables for the definition of normality and the comparison of patients.

Functional jaw muscle assessment in patients with a full fixed prosthesis on a limited number of implants: a review of the literature

BACKGROUND

Full fixed prosthesis on a limited number of implants (FFP) are a viable treatment option for edentulous patients with a reduced amount of residual bone. Jaw muscular function in FFP patients has been evaluated in several studies, however heterogeneous data emerge from literature.

PURPOSE

The aim of this review of the literature was to assess the function of jaw muscles in edentulous patients restored with full fixed prostheses on a limited number (≤ 6) of implants, as compared to dentate subjects and edentulous subjects wearing dentures, implant-supported overdentures or full fixed prostheses supported by more than six implants.

MATERIALS AND METHODS

An electronic search of databases up to December 2013 was performed. The articles were selected using specific inclusion criteria, independent of the study design.

RESULTS

A total of 1598 records were identified. After removing the duplicates and excluding records based on title and abstract, only 37 eligible records were identified. After full-text review, seventeen studies were selected for analysis according to the inclusion criteria. From the included studies, only one evaluated masseter muscle thickness in a cross sectional study by means of ultrasound, while the 16 remaining papers evaluated muscular function by using electromyography (EMG). Those studies analysed several heterogeneous parameters throughout the execution of five functional tests and were therefore described and pooled according to the following task categories: clenching; swallowing; reflex and fatigue for statics; and chewing for dynamics.

CONCLUSIONS

The results of selected studies seem to indicate that, compared to dentate controls, FFP patients display a global satisfactory neuromuscular equilibrium in static activities, but still have some impairment during chewing.

Histological findings on jaw osteonecrosis associated with bisphosphonates (BONJ) or with radiotherapy (ORN) in humans

OBJECTIVE

To describe the histological features of bone tissue harvested from patients affected by jaw osteonecrosis associated with bisphoshponates (BONJ) or with radiotherapy (ORN), in undecalcified ground sections.

MATERIALS AND METHODS

Sixteen bone tissue samples from 14 patients with BONJ and two patients with ORN were processed in order to obtain both ground, undecalcified sections and decalcified sections. The sections underwent histometric and morphometric analysis.

RESULTS

Bone tissue samples obtained from patients with BONJ or ORN of the jaws shared some histological characteristics. Common histological features included the loss of bone architecture, the absence of a proper Haversian system and proper marrow spaces, the presence of necrotic spots of non-mineralized tissue, areas of empty osteocytic lacunae next to areas of hypercellularity, the presence of resorption pits with rare osteoclast-like cells and the presence of bacteria and of an inflammatory infiltrate. A violet rib of tissue characterized by large resorption pits facing was frequently observed between the mineralized bone and the inflammatory infiltrate.

CONCLUSIONS

The histological features of BONJ and ORN are similar and resemble those of osteomyelitis. Even though it is not clear whether infection is the cause or consequence of bone exposure, inflammatory cells, bacteria or their products may have a massive, direct lytic effect on bone tissue challenged by bisphosphonates.

Effect of Poly-L-Lysine coating on titanium osseointegration: from characterization to in vivo studies

Dental implant prostheses cannot preclude a correct and stable implant osseointegration, which is still a challenge and greatly depends on biomaterial-cell interface. Titanium (Ti) coating using polyelectrolyte poly-L-lysine (PLL) may represent an interesting and simple approach, to provide a charged surface net able to improve cell adherence. However, in vitro and in vivo effects of Ti coated with PLL have been poorly investigated. The aims of the present study are (1) to obtain and characterize, chemically and physically, Ti disks coated with PLL (TiPLL); (2) to perform in vitro studies on osteoblast cell lines' cytocompatibility and functionality (alkaline phosphatase [ALP] activity, calcium deposition, proinflammatory interleukin 6 production); (3) to obtain in vivo evidence of osseointegration, using a sheep animal model. XPS, AFM, and contact-angle analyses demonstrated that the Ti disk was successfully covered with PLL, providing higher hydrophilicity to the Ti disk. No cellular toxicity, enhanced calcium deposition, and a decreased tendency toward interleukin-6 production were observed in the osteoblast seeded onto TiPLL. In vivo experiments showed cortical bone microhardness at 3 months significantly improved in the presence of the PLL coating. PLL coating on Ti implants seemed to safely enhance calcium deposition and implant early osseointegration in animals, suggesting promising evidence to optimize the surface properties of dental implants.

A new method to evaluate volumetric changes in sinus augmentation procedure

BACKGROUND

In sinus augmentation procedure, the assessment of volume changes of grafted materials is important both in the clinical practice and in dental research to evaluate the features of filling materials.

PURPOSE

In this study, we assessed the repeatability of a new method proposed to evaluate volumetric changes following sinus lift augmentation procedure.

MATERIALS AND METHODS

In 10 patients, maxillary sinus augmentation procedure with simultaneous implant placement was performed. Maxillary cone beam computer tomographies were taken 1 week after surgery (T1) and 6 months after surgery (T2). At each evaluation the gap inside the implant between the fixture and the bottom of the screw was used as reference point (Rp), and a standardized volume of interest (VOI) centered on the Rp was selected. Masks were chosen to select the graft and bone tissue within the VOI; the volume at T1, T2, and the difference of volume between T1 and T2 were computed. Expert and non-expert operators performed the analysis. Method errors were computed.

RESULTS

The error of the method was 1% for both intra-operator and inter-operator measurements. Tissue contraction at T2 was 19 ± 4% of the total initial volume.

CONCLUSIONS

The standardization of the method allows to obtain repeatable measurements.

Adipose-derived stem cells and rabbit bone regeneration: histomorphometric, immunohistochemical and mechanical characterization

BACKGROUND

In the last few years, several attempts have been made to treat large bone loss, including the use of tissue engineering with osteoinductive scaffolds and cells. This study highlights the role of mesenchymal stem cells from adipose tissue (ASCs; adipose-derived stem cells) in a rabbit bone regeneration model.

METHODS

We compared the neoformed bone tissues achieved by treating critical tibial defects with either hydroxyapatite alone (HA, group I) or hydroxyapatite-autologous ASC constructs (ASCs-HA, group II), investigating their histomorphometric, immunohistochemical and biomechanical properties.

RESULTS

After eight weeks of follow-up, we observed advanced maturation and a spatial distribution of new bone that was more homogeneous in the inner parts of the pores in group II, not just along the walls (as seen in group I). The new tissue expressed osteogenic markers, and biomechanical tests suggested that the newly formed bone in group II had a higher mineral content than that in group I. Although variability in differentiation was observed among the different cell populations in vitro, no differences in bone healing were observed in vivo; the variability seen in vitro was probably due to local microenvironment effects.

CONCLUSIONS

Tibial defects treated with rabbit ASCs-HA showed an improved healing process when compared to the process that occurred when only the scaffold was used. We suggest that implanted ASCs ameliorate the bone reparative process either directly or by recruiting resident progenitor cells.

Iliac crest fresh-frozen allografts and autografts in maxillary and mandibular reconstruction: a histologic and histomorphometric evaluation

AIM

The aim of this paper was to compare histologically and histomorphometrically the osseointegration of iliac crest fresh-frozen allografts and autografts in human pre-prosthetic maxillary and mandibular onlay bone blocks reconstruction.

METHODS

Twelve patients with edentulous atrophic ridges, scheduled for implant-supported prosthetic restorations, underwent reconstruction using iliac crest fresh-frozen allografts (group A, six patients) or autografts (group B, six patients). Four-to-nine months later implants were placed in the augmented areas and bone specimens were simultaneously obtained using trephine burs. The specimens were processed for ground sections and evaluated histologically and histomorphometrically.

RESULTS

The postoperative course was uneventful in all patients in group B and in all except one in group A. Late complications occurred in 5 patients of group A. Dental implants could be inserted in all cases. Specimens from group A showed a vascularized bone with osteoprogenitor stem cells and medium-high grade of bone remodeling. Small areas of necrotic bone were observed sporadically. Sections obtained from group B revealed an advanced stage of bone remodeling. The histomorphometric analysis showed in group A a mean proportion of 24.7±14.7% for lamellar bone, 28.4±13.3% for newly formed bone and 46.9±16.9% for bone marrow; in group B the corresponding values were 25.3±15.3%, 22.9±11.0%, 51.7±15.7%. No statistically significant difference was found (Wilcoxon Test; P>0.05).

CONCLUSION

There were no significant histological differences between group A and B. Larger studies with long term follow-up are needed to confirm that fresh-frozen allografts are a reliable alternative to autografts.

Evaluation of a resorbable collagen matrix infused with rhPDGF-BB in peri-implant soft tissue augmentation: a preliminary report with 3.5 years of observation

Soft tissue augmentation around dental implants in the esthetic region remains a challenging and unpredictable procedure. The ideal surgical technique would include of an off-the-shelf product to minimize morbidity after autogenous grafting procedures. The aim of this study was to use a resorbable collagen matrix (Mucograft) to serve as a scaffold to recombinant human platelet-derived growth factor BB (rhPDGF-BB) to increase peri-implant soft tissue volume in anterior maxillary sites. A total of six patients who had previously undergone a bone regeneration procedure were included in this study. The collagen matrix was applied during stage-two surgery (expanded polytetrafluoroethylene membrane removal and implant placement). Measurements were performed through customized stents by means of endodontic files, and at abutment connection, a soft tissue biopsy specimen was harvested for histologic examination. The healing period was uneventful in all six patients. Measurements were taken apically, centrally, and occlusally for each site. The mean gains in volume from baseline to the 4-month measurement at the apical, central, and occlusal aspects were 0.87 ± 2.13 mm, 2.14 ± 3.27 mm, and 0.35 ± 3.20 mm, respectively. The results showed a moderate increase in the soft tissue volume in esthetic peri-implant sites when applying a collagen matrix infused with rhPDGF-BB. However, the measuring techniques available need to be further improved to record exact changes in the soft tissue volume.

Oral features in five adult patients with Wolf-Hirschhorn syndrome

The Wolf-Hirschhorn syndrome (WHS) is a rare genetic condition presenting with severe mental disability, growth retardation, muscular hypotonia, seizures, craniofacial abnormalities and defects in the cardiovascular, genitourinary and digestive apparata. To date, few data about oral status of afflicted patients were reported, and this syndrome is still unfamiliar among dental and maxillofacial professionals. Aim of the present case series was to provide oral data from five patients with WHS (3 women and 2 men) aged 19-41 years. All patients entered in a long-stay Institution with an inner dental service in 1998 and underwent regular dental examination and hygiene treatment. Neither tooth agenesis or dental size and shape anomalies were found in the analyzed subjects except for one man showing multiple cone-shaped teeth. At the beginning, bad dental and periodontal conditions with gingival signs and recurrent mucosal inflammation were found in all patients. After motivation of their tutors, dental and periodontal parameters were recorded during periodic assessments and a large decrease in the gingival index was found over time. These data could aware dentists about the therapeutic modalities to improve oral health of WHS patients.

Maxillary sinus floor augmentation using a nano-crystalline hydroxyapatite silica gel: case series and 3-month preliminary histological results

The aim of this case series is to histologically examine a new hydroxyapatite in sinus lift procedure after 3 months. Ten 2-stage sinus lifts were performed in 10 healthy patients having initial bone height of 1-2mm and bone width of 5mm, asking for a fixed implant-supported rehabilitation. After graft material augmentation, a rough-surfaced mini-implant was inserted to maintain stability of the sinus widow. A bioptical core containing a mini-implant was retrieved 3 months after maxillary sinus augmentation with NanoBone(®) and processed for undecalcified histology. From the histomorphometric analysis, NanoBone(®) residuals accounted for the 38.26% ± 8.07% of the bioptical volume, marrow spaces for the 29.23% ± 5.18% and bone for the 32.51% ± 4.96% (new bone: 20.64% ± 2.96%, native bone: 11.87% ± 3.27%). Well-mineralized regenerated bone with lamellar parallel-fibred structure and Haversian systems surrounded the residual NanoBone(®) particles. The measured bone-to-implant contact amounted to 26.02% ± 5.46%. No connective tissue was observed at the implant boundary surface. In conclusion, the tested material showed good histological outcomes also 3 months after surgery. In such critical conditions, the use of a rough-surfaced mini-implant showed BIC values supposed to be effective also in case of functional loading. Although longer follow-up and a wider patient size are needed, these preliminary results encourage further research on this biomaterial for implant load also under early stage and critical conditions.

Histological evaluation of the peri-implant tissues of three human-retrieved Straumann implants

The most frequently-used histological parameters to define dental implant osseointegration include bone-to-implant contact and quantitative and qualitative assessments of the surrounding tissue (rate of mineralized/non-mineralized tissue and proportion of lamellar and woven bone compared to soft tissue or bone marrow). The aim of this paper was to present the histological features of the bone tissue surrounding three well-functioning Straumann SLA and SLActive implants placed in two patients after 12 and 60 months of loading. The percentage of osseointegration ranged from 66.4% and 71.9% for SLA surfaces, to 88.3% for the SLActive implant. Such results confirm that osseointegration occurs with high rates of bone-to-implant contact in humans, and that implants can be similarly clinically successful, although they show different bone-to-implant contact values.

Role of autologous rabbit adipose-derived stem cells in the early phases of the repairing process of critical bone defects

Adipose-derived stem cells (ASCs) may represent a novel and efficient tool to promote bone regeneration. In this study, rabbit ASCs were expanded in culture and used for the regeneration of full-thickness bone defects in the proximal epiphysis of tibia of 12 New Zealand rabbits. Defects were implanted with graft material as follows: untreated (control), empty hydroxyapatite (HA) disk, ASCs alone, and HA disk seeded with ASCs. Each isolated ASCs population was tested in vitro: they all showed a high proliferation rate, a marked clonogenic ability, and osteogenic differentiation potential. Eight weeks after implantation, macroscopic analyses of all the samples showed satisfactory filling of the lesions without any significant differences in term of stiffness between groups treated with or without cells (p > 0.05). In both the scaffold-treated groups, a good osteointegration was radiographically observed. Even if HA was not completely reabsorbed, ASCs-loaded HA displayed a higher scaffold resorption than the unloaded ones. Histological analyses showed that the osteogenic abilities of the scaffold-treated defects was greater than those of scaffold-free samples, and in particular new formed bone was more mature and more similar to native bone in presence of ASCs. These results demonstrated that autologous ASCs-HA constructs is a potential treatment for the regeneration of bone defects.

Craniofacial growth in ectodermal dysplasia. An 8 year longitudinal evaluation of Italian subjects

OBJECTIVE

To identify the main directions of growth of facial structures in subjects with hypohidrotic ectodermal dysplasia (HED).

MATERIALS AND METHODS

The 3D noninvasive facial measurements were collected in 12 subjects (6 boys, 6 girls) with HED during four assessments (at 8, 11, 12, and 15 years) using an electromagnetic digitizer. The modifications of linear distances in the upper, middle, and lower third of the face were analyzed and compared with cross-sectional data obtained in normal healthy coetaneous. For each distance, differential values between the last and the initial data were calculated individually, separately for a first (8-11 years) and a second growth period (12-15 years).

RESULTS

In the first time span, the growth of all facial measurements was reduced in HED subjects compared with control subjects. During this interval, most of the HED children underwent a functional and/or prosthetic treatment. During adolescence, the width and height of the lower and upper facial thirds showed a larger growth in HED subjects than in control subjects, while all facial depths and all distances in the middle facial third maintained a reduced growth.

CONCLUSIONS

The deviation from normal facial growth of HED subjects tends to lessen with age. Functional and prosthetic appliances may have enhanced facial growth.

Socket grafting in the posterior maxilla reduces the need for sinus augmentation

This study compared the dimensional alterations, the need for sinus floor elevation, and the histologic wound healing of augmented and nonaugmented alveolar sockets. Sixteen human extraction sockets were either grafted or left untreated. At baseline and 3 and 6 months postextraction, alveolar ridge alterations were evaluated; at 3, 6, and 9 months, histologic analyses were conducted. Implant placement with or without sinus floor augmentation was decided at 6 months. Three of eight patients in the control group underwent sinus floor augmentation compared to one of six in the experimental group. The alveolar ridge augmentation procedure presented here increases the possibility of inserting implants without the need for a sinus augmentation procedure.

Special care dentistry for people with intellectual disability in dental education: an Italian experience

AIM

This study documented: (i) the curriculum in special care dentistry in the Italian dental schools, as perceived by Deans and by students, (ii) the rate of satisfaction of dental students with their curricular education in special care dentistry, (iii) the attitude of the dental students towards special care dentistry and towards the 'Special Smiles' programme.

METHODS

The quality and amount of didactic and clinical training delivered by each dental school for subjects with intellectual disability (ID), the interest of students towards this health field and the 'Special Smiles' programme were collected. Self-administered surveys were sent to the Dean and to all the final year students of all dental schools in 20 Italian Universities.

RESULTS

Only four Deans of the 20 dental schools answered the survey, stating to provide didactic and clinical education in special care dentistry. A 51% of student response rate was obtained. Dental students reported to spend about 4% of didactic and 5% of clinical training in the dental care for ID subjects. Most students (83%) rated the training they had received on the topic to be poor. Over 50% of students expressed interest in working in dental offices specifically dedicated to ID patients and 25% of students wished to become Special Smiles volunteers.

CONCLUSIONS

Although the paucity of didactic and clinical training in dental care for ID patients, this survey demonstrated a high level of student's interest in learning more about treating these subjects. The current results could suggest to revise the curricular standards of dental schools, by promoting ID-oriented education programmes.

Histomorphometric analysis of human maxillary sinus lift with a new bone substitute biocomposite: a preliminary report

PURPOSE

To analyze radiographic and histological outcomes of maxillary sinus floor augmentation using a calcium-sulfate based allograft containing demineralized bone matrix particles.

MATERIALS AND METHODS

Fifteen maxillary sinus lift procedures with simultaneous placement of titanium implants were performed in 12 patients of both genders aged 36-71 years. Each sinus cavity was filled by the biocomposite. After 3 months of healing, all surgical sites were uncovered and bone biopsies were retrieved for undecalcified histology and histomorphometry. The ratio between the original and the grafted sinus height (GSH/OSH) was computed using a panoramic radiography taken immediately after surgery and at 3 months of healing, and the two ratios were compared by Wilcoxon signed-rank test.

RESULTS

By 3 months, all implants were stable without clinical and radiographic signs of infection. Significant changes in GSH/OSH during healing were seen (2.7 +/- 0.6 initially vs. 2.6 +/- 0.5 after healing; p = 0.01). Histologic findings showed newly formed bone surrounding the residual grafted particles without inflammation. At 3 months, mean regenerated bone density was 33.8 +/- 8.6%; marrow spaces amounted to 32.3 +/- 10.3%; residual graft was 33.9 +/- 9.0%. Similar histomorphometric and radiographic results were obtained independently from patient age or sex.

CONCLUSIONS

The analysed putty seems to be a safe and effective graft material for maxillary sinus floor augmentation by accelerating bone regeneration and thus reducing the healing time.

Postural stability of athletes in Special Olympics

To assess body equilibrium in athletes with intellectual disability, 60 adults with intellectual disability (30 Down syndrome, 30 nonsyndromic) participating in the 2005 Italian Special Olympics games were tested, and data for 30 healthy control adults were tested. Each subject performed four posturographic tests with open eyes, open eyes and cotton rolls between antagonist teeth, and closed eyes and cotton rolls between teeth. For each subject and test, oscillations of the body's center of foot pressure on a force platform were measured. Comparisons of the center of foot pressure sway area between groups were computed. Ratios of the sway area for the center of foot pressure among experimental conditions were compared for all athletes. The athletes with Down syndrome had larger sway of center of foot pressure area than controls and smaller than that of athletes for the nonsyndromic. All participants oscillated less with open eyes than with closed eyes. The cotton rolls reduced the sway area for the center of foot pressure by participants, while athletes with intellectual disability showed larger body sway than healthy ones, but cotton rolls between the teeth seemed to improve their postural performance.

Relationship between facial morphology and cervical vertebral shape: a radiographic investigation

AIM

The aim of this study was to investigate the relationships between the characteristics of cervical vertebrae and craniofacial morphology using a global mathematical method.

METHODS

Several cephalometric measurements and the outlines of the second (C2) and fourth (C4) cervical vertebrae were obtained from 45 head films (32 females aged 20-40 years; 13 males aged 21-37 years). Vertebral outlines were mathematically obtained by Fourier series, and the morphological distance between each outline and a reference one was computed. Linear correlations were run between cephalometric variables and morphological distances.

RESULTS

Significant correlations (P<0.05) were found between anterior cranial base length (sella-nasion) and the morphological distance of C4 (subjects with a longer cranial base differ more from the reference vertebral outline), and between maxillary length and the morphological distance of C2 (subjects with a shorter maxilla differ more from the reference vertebral outline). The relationship between mandibular base length (Go-Me) and the morphological distance of C2 (subjects with a shorter mandible differ more from the reference vertebral outline) was nearly significant. Within each subject, the two analyzed vertebrae had independent relationships with the reference outlines.

CONCLUSION

A significant but limited relationship between craniofacial structures and vertebral morphology was found: at the best, 10% of the differences between the individual vertebral morphology and the reference one may be explained by craniofacial cephalometric measurements. The differences found between C2 and C4 morphologies may show a different effect of suboccipital muscles and of neck muscles within the theories of the functional matrix hypothesis.

Nasal base symmetry: a three dimensional anthropometric study

AIM

The aim of this paper was to evaluate directional and fluctuating asymmetry, nostril and alar divergence in the nasal base of healthy young adults. To estimate nostril area and to investigate its relationships with cutaneous nasal area.

METHODS

Three-dimensional plaster models of the nose of 20 young healthy white adults were obtained, digitized and mathematically reconstructed using Non Uniform Rational B-Splines (NURBS) curves. Linear distances (alar length, nostril axis length), angles (interalar angle, interaxial angle; angle between each nostril and alar axes), and surface areas (cutaneous nasal surface; right and left nostril area) were computed using NURBS-reconstructed models.

RESULTS

The left side nasal structures were somewhat larger than the homologous right side ones (P<0.05). Nostril axis was approximately 60% of the corresponding alar length. Nostril area was approximately 3% of cutaneous nasal area. Alar length explained 31-36% of the individual variations in nostril axis length. Cutaneous nasal area explained 54-56% of nostril area, while the interalar angle explained 35% of the variations in interaxial angle.

CONCLUSIONS

The method provided simple measurements of nasal base dimensions and asymmetry; some asymmetry was found also in healthy adults; only moderate relationships between nostril and alar dimensions and angles, as well as between nasal and nostril areas, were found, thus pointing to the necessity of detailed nostril assessments.

Sinus grafting using autogenous bone and platelet-rich plasma: histologic outcomes in humans

Four partially edentulous patients received particulate autogenous bone and platelet-rich plasma (PRP) in one sinus and particulate autogenous bone alone in the contralateral sinus. After 6 months of healing, two or three Osseotite implants were inserted, and an additional Osseotite mini-implant was placed into the graft through the lateral wall of the sinus. At abutment connection, the mini-implants were retrieved for histologic examination. Despite similar clinical and radiographic healing patterns, a higher bone-to-implant contact rate was observed on the implants placed in bone and PRP than on those placed in bone only (46.75% +/- 13.6% versus 20.5% +/- 5.57%, respectively).

Biocompatibility and manageability of a new fixable bone graft for the treatment of localized bone defects: preliminary study in a dog model

The present investigation was performed to compare the biocompatibility, safety, and manageability of a newly developed bone block and a deproteinized bovine bone block (Bio-Oss) for the treatment of localized bone defects in a dog model. Two male beagle dogs were used for this study. The mandibular premolars were extracted and two saddle-type defects were created bilaterally in the edentulous area. The defects were filled according to a randomized design with Bio-Oss bone block or with an equine hydroxyapatite plus collagen bone block (eHAC). Most control and test sites developed dehiscences during healing. After 4 weeks, the animals were euthanized and each hemimandible was prepared for histologic examination. No significant difference in terms of local tolerance was observed between test and control sites, and test and control sites showed similar histologic findings. However, a significant difference was noticed between the Bio-Oss block and the new bone block in terms of manageability.

Non-invasive longitudinal assessment of facial growth in children and adolescents with hypohidrotic ectodermal dysplasia

Facial growth patterns in 12 subjects (six boys and six girls) with hypohidrotic ectodermal dysplasia (HED) were analyzed and compared with facial growth patterns obtained in healthy reference peers. All subjects with HED were aged 7 yr (mean age +/- standard deviation: 7.08 +/- 0.41 yr) at the first examination and 14 yr (mean age +/- standard deviation: 14.56 +/- 0.34 yr) at the last examination. In each subject, the three-dimensional coordinates of facial landmarks were collected non-invasively at eight subsequent years. The volumes of forehead, nose, maxilla and mandible, upper lips, and lower lips were estimated. For each facial volume, differential values between different time points were calculated individually, separately for the 'childhood' (7-10 yr) and the 'adolescence' (11-14 yr) growth period in both HED and reference subjects. Children and adolescents with HED had a slightly reduced global facial growth in comparison with normal reference peers. The peak mandibular and maxillary development was delayed by approximately 2 yr towards later adolescence. The present non-invasive system seems to be useful for studying longitudinal changes of facial growth in healthy and syndromic subjects.

Three-dimensional facial morphometry of attractive children and normal children in the deciduous and early mixed dentition

OBJECTIVES

To identify possible esthetic canons in facial size and shape of Italian children.

MATERIALS AND METHODS

The three-dimensional coordinates of 50 facial landmarks (forehead, eyes, nose, cheeks, mouth, jaw, ears) were collected in 220 healthy reference children (4-9 years old) and in 89 "attractive" children of a similar age group selected by a commercial casting organization. Soft-tissue facial angles, distances, and volumes were computed. Comparisons were made with the Student's t-test.

RESULTS

Attractive children had a larger face than the reference children, with a larger maxilla and forehead; overall, their faces were wider and deeper, but less vertically developed. Lips were more voluminous in attractive children, with a higher mouth. The nose was larger in attractive children than in reference children. The soft-tissue facial profile was more convex in attractive children, with a more prominent maxilla relative to the mandible.

CONCLUSIONS

Overall, considering that in the analyzed ages body growth and dental changes are very fast and individually determined, all the measurements appeared sufficiently homogenous, and the quantitative characteristics of an "attractive" face well defined. Esthetic reference values can be used to determine optimal timing and goals in orthodontic treatment.

Occlusal morphology 1 year after orthodontic and surgical-orthodontic therapy

OBJECTIVE

To evaluate morphologic characteristics of occlusion (contact points, contact areas, and frequency of contact) in clinically successful patients 1 year after orthodontic and surgical-orthodontic therapy followed by passive retention.

MATERIALS AND METHODS

Twenty-two orthodontic and 18 surgical-orthodontic patients were analyzed. All patients were treated with standard edgewise technique by the same orthodontist. Contact points and areas were evaluated using a new method of digital image analysis of occlusal impressions. Polivinylsyloxan impressions were taken, scanned, and turned into gray-scale images. The physic relationship of light absorbance through the polivinylsyloxan for known thickness was calculated to determine contact areas (less than 50 microm of thickness) and near contact areas (less than 350 microm of thickness).

RESULTS

The contact area was significantly larger in the orthodontic than in the surgical-orthodontic patients (Student's t-test, P < .05). The surgical-orthodontic group had significantly fewer contact points than the orthodontic group only at 150 microm of thickness. In both groups of patients, the first molar had the largest contact surface. Occlusal support was distributed mainly in the posterior regions with an important role involving the first molars.

CONCLUSION

Surgical-orthodontic patients appear to have smaller contact surfaces and fewer contact points than orthodontic patients do. However, there were no differences in the number of teeth in contact with opposing teeth.

Bone regenerated via rhPDGF-bB and a deproteinized bovine bone matrix: backscattered electron microscopic element analysis

This study used backscattered electron microscopy (BSE-SEM) to analyze specimens in which bone was augmented both horizontally and vertically with a xenograft scaffold and recombinant human platelet-derived growth factor (rhPDGF-BB), with or without a resorbable collagen membrane. The study objective was to compare percentage weight and volume calcium-phosphorus ratios of regenerated bone and native bone and the nature of the bony contact with two different implant surfaces. Examination of the nature of the mineralized tissues by BSE-SEM provides an understanding of the composition and element ratio of bone regenerated from nonautogenous grafts. The data collected demonstrated no statistically significant difference between regenerated bone and native bone in the two tested groups. Our observations suggest that bone regenerated via nonautogenous grafts displays composition, structure, and physical properties very similar to those of native bone. Similarly, no significant differences were observed at the bone-implant interface between bone regenerated proximal to oxidized versus machined implants.

Three-dimensional hard tissue palatal size and shape in Down syndrome subjects

The aim of the present study was to evaluate palatal morphology in Down syndrome (Ds) subjects, focusing on the effect of dental formula on the hard palate to assist clinicians when planning dental rehabilitation. Palatal landmarks were digitized with a three-dimensional (3D) computerized digitizer on the dental casts of 47 Ds subjects (23 dentate males, 9 edentulous males, and 15 dentate females) aged 20-45 years, 37 dentate reference individuals (20 males and 17 females) aged 30-39 years, and 14 edentulous reference males aged 55-72 years. The co-ordinates of the palatal landmarks were used to construct a mathematical equation of palatal shape, independent of dimensions. Palatal length, slope, width, and maximum palatal height in both the sagittal and frontal planes were measured. In males, palatal length, width, and height were significantly influenced by both the syndrome and edentulism (analysis of variance, P < 0.05). The same measurements were significantly reduced in Ds compared with dentate females (t-test, P < 0.05). In the sagittal plane, Ds did not modify palatal shape; in the frontal plane, Ds individuals showed a higher palate. Overall, palatal shape was influenced by both Ds and edentulousness. Therefore, Ds seems to alter the normal palatal size and shape, although verification on larger samples is required. The findings of the present study may encourage more interdisciplinary dentofacial therapy in the dental and orthodontic care of Ds subjects.

Electromyographic evaluation of implant-supported prostheses in hemimandibulectomy-reconstructed patients

OBJECTIVES

To assess the clinical conditions, patient's satisfaction and functional outcomes in oral neoplasia patients with hemimandibulectomy, bone reconstruction and implant-supported prosthesis.

MATERIAL AND METHODS

Twelve patients after mandibular resection (with and without condyle), reconstruction and successful fixed implant-supported prosthesis rehabilitation were examined. Patients underwent clinical evaluation and filled in a questionnaire about their satisfaction toward oral functions. Surface electromyography (EMG) of the masticatory muscles was performed during a 15-s unilateral gum chewing test. EMG potentials were standardized as percentage of a maximum clench on cotton rolls and compared with reference data obtained from 20 healthy subjects.

RESULTS

Excellent clinical and radiological parameters were found. Patients stated a decreased post-rehabilitation satisfaction toward mastication and phonetics, but an increased attention to oral care. Only patients with condylar resection reported augmented esthetic scores. In both the resected and the remaining sides, chewing frequency was higher in the patients than in the reference group (Wilcoxon's rank-sum test, P<0.001). Pooled muscle activities (sum of the integrated areas of the EMG potentials over time) were larger in patients than in control subjects, particularly in the non-operated side (P=0.001). The percentage contribution of working-side muscular activity in the operated side was similar to reference values, but significantly inferior in the opposite side (P<0.001). The patterns of muscle contraction during unilateral chewing were more variable in the reconstructed patients than in control subjects; the difference was significant only in the non-operated side (P<0.01).

CONCLUSION

Post-rehabilitation median scores of the questionnaire indicated a positive judgment of the treatment. EMG analysis showed that functional recovery in hemimandibulectomy patients was satisfactory, although some alterations were observed in the non-operated side of mastication.

Two-dimensional vs three-dimensional assessment of soft tissue facial profile: a non invasive study in 6-year-old healthy children

AIM

In medical practice, the analysis of facial soft tissues often complement (or even supplement) the evaluation of the hard-tissue relationships. Current technology provides reference data in three dimensions, but clinical practice still uses two-dimensional photographs. In the current study, two-dimensional photographic and computerized, three-dimensional angles measured on the facial profile of children were compared.

METHODS

Two-dimensional angular measurements (facial convexity including/excluding the nose; maxillary prominence; nasal prominence; nasolabial; mentolabial; maxillo-labio-mandibular; interlabial) were obtained on the facial profile photographs of 55 boys and 31 girls aged 6; measurements were compared to three-dimensional computerized data collected on 27 boys and 28 girls of the same age and ethnic group.

RESULTS

On average, in boys, only the angles of facial convexity including the nose, interlabial, nasolabial and maxillo-labio-mandibular showed differences between the means larger than 2 degrees (up to 2.5 degrees). Statistically significant differences (P<0.05, Watson-Williams' test) were found for the angle of facial convexity including the nose and the maxillary prominence angle. In girls, differences between the two methods larger than 2 degrees were found for the interlabial, maxillo-labio-mandibular (statistically significant), and mentolabial angles (differences up to 7 degrees, corresponding to 4% of the relevant mean).

CONCLUSION

The two-dimensional photographic and the three-dimensional computerized data compared in the current study, even not superimposable, seemed sufficiently interchangeable, at least from a clinical point of view. A particular attention should be given to the recording of lip position.

Three-dimensional ridge augmentation with xenograft and recombinant human platelet-derived growth factor-BB in humans: report of two cases

The present paper reports on two patients who underwent three-dimensional ridge augmentation using a xenograft in combination with recombinant human platelet-derived growth factor-BB (rhPDGF-BB). Patient 1 received a deproteinized bovine block infused with PDGF and secured to the alveolar crest by two fixation screws to augment the crest horizontally. After 5 months, implants were successfully placed. Patient 2 underwent a vertical ridge augmentation procedure that combined deproteinized bovine bone particles embedded in a collagen matrix soaked in PDGF Three titanium dental implants were placed in each patient 5 months later. Clinical and histologic results showed excellent soft and hard tissue healing. Bone had regenerated throughout the whole area and the xenograft particles were embedded in bone, which presented resorption lacunae close to areas with ongoing bone formation. This indicated that, in augmented areas, intense physiologic remodeling was ongoing. No data exist concerning three-dimensional bone augmentation using PDGF and a xenograft in humans. This report suggests that the use of rhPDGF-BB in combination with a deproteinized bovine graft may have the potential to regenerate large three-dimensional alveolar defects in humans.

Three-dimensional facial morphometry of attractive Italian women

OBJECTIVES

To identify reference standards and possible esthetic features in facial proportion and form of Italian adult women.

METHODS AND SUBJECTS

A three-dimensional electromagnetic digitizer was used to collect the coordinates of 50 facial landmarks (forehead, eyes, nose, cheeks, mouth, jaw, ears) in 71 healthy, reference women (18-30 years old) and in 48 "attractive" women selected during a beauty competition; soft tissue facial angles, distances and volumes were computed.

RESULTS

Attractive women had wider faces with a relatively larger upper facial third (forehead); a larger facial width relative to facial height. The mouth was larger, and lips were more prominent; the interlabial angle was reduced. Overall, the soft-tissue profile was more prominent, with a larger maxillary prominence relative to the mandible. Faces in the attractive women were more flat in the horizontal plane. For several of the analyzed measurements, similar patterns were observed for the 36 women participants to the semi-final stage of the beauty competition, the 12 finalists, and the winner. The winner of the beauty competition deviated from the reference women more than the other two groups of attractive women.

CONCLUSION

Esthetic reference values were determined for a population of 18-30 year olds that reflect contemporary society.