Development of a teledentistry system for the elderly in the context of the COVID-19 pandemic: 3D diagnostic models integration in a web platform

Objective: To recognize the usefulness of incorporating Three-Dimensional models of standardized humans in electronic health records, in the context of the development of a teledentistry web platform designed for the attention of the elderly population in COVID-19 pandemic context. Material and Methods: A teledentistry web platform designed with different modules for clinical records. Through a new user-computer interface with a standardized virtual 3D phantom, an extraoral physical examination, an intraoral examination section was modeled. A label-associated marker is allowed to record descriptive aspects of the findings. A 3D odontogram represents multiple patient’s conditions for each of the 32 dental positions. Results: From a total of 135 patients registered on the platform, 51 markers and 33 photographs associated with the surface of the virtual 3D phantoms were recorded. For the Location parameter: Hard palate 27.6%, inserted gingiva 15.7%, tongue 15.6%. For the Type of lesion parameter (according to the information entered in the pathology selector): unidentified 35.3%, sub-prosthetic stomatitis 23.5%, irritative fibroma 9.8%. Through the registration of the exact location of the finding in the virtual phantom by a 3D marker, the 3D modeling of the oral pathologies contributed to a better diagnosis, improving the remote communication between the attending dentist and specialists. Conclusion: The combination of the 3D modeling and anatomical-referencing in a teledentistry platform can become a powerful tool for the dental practice, due to their utility and specificity.

Sinus Floor Augmentation by Intraoral Endoscopic Approach for Biomaterial Study in a Rabbit Model

AIM

To develop a new surgical model for sinus floor augmentation (SFA) in rabbit for experimental purposes.

MATERIALS AND METHODS

Eight adult rabbits were used, two for a surgical design using the anatomical dissection study, and the other six for an endoscopically assisted intraoral approach of SFA unilaterally, creating a subantral space where an allograft biomaterial was deposited. SFA was verified through cone-beam computerized tomography. Healing, weight, food, feces, and behavior were evaluated for 4 weeks post-operatively.

RESULTS

All animals survived. There was no bleeding or infection; inflammation was mild. No changes were observed in terms of feeding, weight, feces, or behavior. Tissue healing was normal.

CONCLUSION

This model is a refinement of the experimental technique and is a real option for SFA, without compromising animal morbidity because of its conservative design. The minimally invasive approach with endoscopic assistance reduces bias and improves surgical predictability.

Accuracy of Navigation-Guided Dental Implant Placement with Screw Versus Hand Template Fixation in the Edentulous Mandible

PURPOSE

Preoperative planning of the implant position as part of a coordinated prosthetic and surgical concept is becoming increasingly important regarding function and esthetics. The aim of this study was to investigate the transmission accuracy of template fixation during surgery in edentulous arches with hand fixation in comparison to intermediary screw fixation.

MATERIALS AND METHODS

Preoperatively, 10 implant positions were planned using computed tomography (CT) with the system med3D for implant placement in four mandible models of the Goettingen study model, using a prosthetic diagnostic template. A total of 40 implant insertions were created. For every 20 insertions, the template was temporarily fixed with three screws and compared with the insertion using a hand-fixed template. The precision of the transmission was evaluated with and without screw fixation by re-evaluating the preimplant planning with additional CT scanning of the respective models.

RESULTS

Compared with the hand-fixed procedure (HFG) in the model situation, there were no significant differences between the deviations of planned and final implant position in the screw-fixed group (FG). According to the study results, the fixed procedure leads to less depth deviation and lateral error of the implant base in relation to the HFG. Within both groups, there were significant differences between the radial deviation tendencies from the implant base to the implant apex (P = .033 for FG and P = .001 for HFG).

CONCLUSION

The use of CT-based implant planning succeeds in fixed and hand-fixed surgical procedures with high precision in the atrophic, edentulous mandible model. According to the results of this study, in cases demanding high depth precision, screw-fixation of the template can be helpful.

Inward fragmentation and socket preservation in complex mandibular third molar surgery - A Case Report

Open extraction sockets following inward fragmentation of partially erupted mandibular third molars may compromise the hard tissue regeneration and lead to postoperative complications. In the case report, we present socket preservation to seal the open alveolous without flap displacement. A female patient aged 22, presented for removal of a partially erupted M3M was operated on via occlusal inward fragmentation under magnifying endoscopic vision. Critical nerve structures were identified and protected before socket preservation with resorbable in situ hardening TCP particles was performed. The alveolar bone site healed uneventful, panoramic and cross-sectional conebeam reformats confirmed an complete hard tissue maintanence. Endoscopically assisted inward fragmentation combined with socket preservation leads to the maintenance of adjacent hard tissues without need for flap transposition in complex anatomical sites.

Novel use of cranial epidural space in rabbits as an animal model to investigate bone volume augmentation potential of different bone graft substitutes

Background

The success of bone augmentation to a major degree depends on the biomechanics and biological conditions of the surrounding tissues. Therefore, an animal model is needed providing anatomical sites with similar mechanical pressures for comparing its influence on different biomaterials for bone regeneration. The present report describes the new bone formation associated to biomaterial in a bursa created in the epidural space, between dura mater and cranial calvaria, under the constant pressure of cerebrospinal fluid.

Methods

Five adult California rabbits were used for the trial. In each animal, two bursae were created in the epidural spaces, in the anterior part of the skull, below both sides of the interfrontal suture. The spaces between dura mater and cranial calvaria were filled with in-situ hardening biphasic calcium phosphate containing hydroxyapatite and beta tricalcium-phosphate (BCP), in-situ hardening phase-pure beta-tricalcium phosphate (β-TCP) or without any biomaterials (sham). After 90 days, the animals were sacrificed, and the defect sites were extracted and processed for histomorphometric analysis by optical and backscattered electron microscopy.

Results

The cranial epidural spaces created (n = 10) could be preserved by the application both BCP (n = 3) and β-TCP biomaterials (n = 3) in all experimental sites. The sites augmented with BCP showed less new bone formation but a trend to better volume preservation than the sites augmented with β-TCP. However, the bone in the BCP sites seemed to be more mature as indicated by the higher percentage of lamellar bone in the sites. In contrast, the created space could not be preserved, and new bone formation was scarce in the sham-operated sites (n = 4).

Conclusion

The experimental bursae created bilaterally in the epidural space allows comparing objectively bone formation in relation to biomaterials for bone regeneration under permanent physiological forces from cerebrospinal fluid pressure.

Interaction between deglutition, tongue posture, and malocclusion: A comparison of intraoral compartment formation in subjects with neutral occlusion or different types of malocclusion

OBJECTIVE

To test the null hypothesis of no significant difference in terms of intraoral pressure curve characteristics assessed simultaneously at the subpalatal space (SPS) and the vestibular space (VS), during different oral postures, between four groups with either an Angle Class II/1 (II1), Angle Class II/2 (II2), anterior open bite (O) malocclusion, or a neutral occlusion control group (I).

MATERIALS AND METHODS

Intraoral pressure recordings were performed simultaneously in the VS and SPS of 69 consecutive subjects (nII1  =  15; nII2  =  17; nO  =  17; nI  =  20; mean age/standard deviation 18.43/6.60 years). Assessments included defined sections of open mouth posture (OMP, 30 seconds), anteriorly closed mouth condition (60 seconds), dynamics by a tongue-repositioning maneuver (TRM, 60 seconds), swallowing, and positive pressure generation (PP, 10 seconds). Interactions of malocclusion, compartment location, and posture on pressure curve characteristics were analyzed by Kruskal-Wallis and Mann-Whitney U-tests, adopting an α level of 5%.

RESULTS

Globally significant group differences were detected at the VS (plateau duration and median peak heights during TRM; area under pressure curve [AUC] during PP) and SPS (AUC during TRM and PP). Subjects with anteriorly nonopen dental configurations (groups I and II2) were able to keep negative pressure levels at the VS for longer time periods during TRM, compared to groups O and II1.

CONCLUSIONS

The null hypothesis was rejected for mean VS plateau durations and peak heights and for SPS AUC. Negative pressures at the VS may stabilize outer soft tissues passively and may explain the dental arch form shaping effect by mimic muscles.

Can tongue shadow in panoramic radiographs be avoided by using the tongue repositioning maneuver?

OBJECTIVE

The purpose of this study was to evaluate the use of the tongue repositioning maneuver (TRM) during panoramic radiography so as to avoid the error of tongue shadow.

STUDY DESIGN

A total of 300 panoramic radiographs were evaluated. One hundred and fifty orthopantomograms with conventional positioning technique were used as a control group, while other 150 were taken with the patient performing the TRM. The tongue shadow was measured in each radiograph in the first molar regions bilaterally and in the midsagittal plane. Wilcoxon Mann-Whitney U-Test was used to test the significance difference between the groups.

RESULTS

The tongue-palate distance in the study group was reduced from a mean value of 6.4 mm to 1 mm in the right first molar, 8.0 mm to 2.2 mm in the midsagittal region, and 6.6 mm to 1.2 mm in the left first molar position. Statistical evaluation exhibited significant differences of tongue shadow at all measuring sites between study and control group (P < .0001).

CONCLUSIONS

The present study demonstrates that the TRM leads to a substantial reduction of the tongue position error in panoramic radiography.

Description of intraoral pressures on sub-palatal space in young adult patients with normal occlusion

Under normal conditions, the oral cavity presents a perfect system of equilibrium between teeth, soft tissues and tongue. The equilibrium of soft tissues forms a closed capsular matrix, generating differences with the atmospheric environment. This difference is known as intraoral pressure. Negative intraoral pressure is fundamental to the stabilization of the soft palate and tongue, reducing neuromuscular activity for the permeability of the respiratory tract. Thus, the aim of this study was to describe the variations of intraoral pressure of the sub-palatal space (SPS) under different physiological conditions and biofunctional phases. A case series was conducted with 20 individuals aged between 18 and 25. The intraoral pressures were measured through a system of cannulae connected to a digital pressure meter in the SPS during seven biofunctional phases. Descriptive statistics were used based on the mean and standard deviation. The data recorded pressure variations under physiological conditions, reaching 65 mbar as the intraoral peak in forced inspiration. In the swallowing phase, peaks reached -91.9 mbar. No pressure variations were recorded in terms of atmospheric changes with the mouth open and semi-open. The data obtained during the swallowing and forced inspiration phases indicated forced lingual activity. In the swallowing phase, the adequate position of the tongue creates negative intraoral pressure, which represents a fundamental mechanism for the physical stabilization of the soft palate. This information could contribute to subsequent research into the treatment of primary roncopathies.

Compressive resistance of abutments with different diameters and transmucosal heights in Morse-taper implants

The aim of this study was to evaluate the compressive resistance under oblique loads of abutments with two different diameters and transmucosal heights used for cement-retained implant-supported prostheses in Morse-taper implants. Forty Morse-taper implants were divided into four groups with different abutment sizes for cement-retained prostheses in order to perform the compressive test. The groups were divided by abutment diameter and transmucosal height as follows: Group 1: 4.5 x 2.5 mm; Group 2: 4.5 x 3.5 mm; Group 3: 3.3 x 2.5 mm; and Group 4: 3.3 x 3.5 mm. An oblique compressive loading test was performed on each sample located in a platform at 30° using a universal testing machine with a load cell of 1,000 kgf and 0.5 mm/min speed until achieving the deformation of abutment's neck. The compressive resistance and its mechanical behavior were recorded for each group and the data were analyzed using ANOVA, the Shapiro-Wilk and Scheffé tests. In addition, the detailed damage of all samples was recorded with a conventional camera linked to the endoscopic equipment. Significant differences were observed among the groups, except between Groups 2 and 3 (p>0.005). All the abutments showed permanent deformations in the upper region and at the transmucosal portion, but the threads of the screws were intact. Fractures were only identified in Groups 3 and 4. Stronger mechanical behavior and compressive resistance was observed in the abutments with 4.5 mm diameter and 2.5 mm transmucosal height.

In vitro visualization of human endodontic structures using different endoscope systems

Different endoscope optics for the visualization of interradicular structures were evaluated as a diagnostic tool. A sample of 20 extracted human lower molar teeth was used. Only teeth with fully formed apices were included. All samples were evaluated with three different endoscopic procedures: pulp endoscopy (PE), canal entrance endoscopy (CEE) and root canal endoscopy (RCE). All pulp chambers could be observed using PE (100%), however, only 41 of 60 (68.3%) canals were observed. With CEE, all entrances could be observed, and the middle third of the canals could be visualized in 85% of the canals. The semiflexible endoscope for RCE allowed successful observation of 91.6% of the middle third of the canals. The application of the endoscope may be useful in the identification of root canals even under difficult visual work field conditions. The combined use of a set of various optics might enable the operator to enhance the quality of non-surgical endodontic procedures.

Bone augmentation in rabbit tibia using microfixed cobalt-chromium membranes with whole blood, tricalcium phosphate and bone marrow cells

To assess bone augmentation based on a non-critical defect, 1.5 mm deep cobalt-chromium (Co-Cr) barrier membranes were placed on seven adult California rabbits with three different grafting situations: whole blood, whole blood with tricalcium phosphate (TCP), and TCP mixed with bone marrow cells. Macroscopic assessment of the animals was performed once a week and densitometric studies were performed once a month. Three months post-surgery, after detaching the membranes, tibias were sectioned and followed the routine laboratory processing for decalcified sections, with inclusion in paraffin and staining by hematoxylin and eosin technique. Bone augmentation was observed for each animal, even sometimes over the Co-Cr membranes. Compact bone was mostly observed for every situation, with a higher cellular activity on those samples with bone grafts. This could be due to the presence of graft remains at the growth area. It could be concluded that blood supply to the site providing growth factors by the blood clot formation, and the placement of an osteoconductive non-resolvable membrane that favors osseoinduction, may be sufficient elements to achieve bone augmentation in a period of three months in rabbit tibia.

Radiographical and clinical evaluation of critical size defects in rabbit calvaria filled with allograft and autograft: a pilot study

Regeneration of resorbed edentulous sites can be induced by bone grafts from the subject himself and/or by the use of biomaterials. At present, there has been an extensive search for biomaterials that are evaluated by artificially creating one or more critical defects. The aim of this work was to clinically and radiographically analyze bone formation by the use of some biomaterials in artificially created defects in the parietal bone of rabbits. Six rabbits were used, creating defects of 8 mm in diameter in parietal bones. One defect was maintained with coagulum only, and in others, freeze-dried bone allograft (FDBA), autologous bone, and a combination of autologous bone with FDBA respectively, were added. Animals were sacrificed at 15-90 days with 2 weeks interval each, and calvaria were analyzed macroscopically, measuring by digital caliper the lack of filling at the surface of defects, identifying limits at anteroposterior and coronal view, realizing a digital photograph register of their external surfaces. This was subsequently evaluated radiographically by occlusal film radiography used to quantify its density through software. In conclusion, autologous bone showed the best behavior, clinically as well as radiographically. However, FDBA is a good option as an alternative to autologous bone as its behavior was slightly lower over time. The combination of autologous bone and FDBA in the same defect showed results considerably inferior to grafts used separately. Low radiopacity and clear limits were observed through time for the control coagulum filled defect.

Occlusive barriers in combination with particulate Bio-Oss® graft: a pilot study on rabbit calvaria

The aim of this study was to histologically evaluate the potential for vertical bone augmentation of the Bio-Oss® graft compared to a blood clot in conjunction with an occlusive barrier in the rabbit calvaria defect model. Metallic dome shaped barriers with 4.5 mm width and 3.5 mm height were positioned in six adult rabbit skulls. At the right side, the barrier was filled with Bio-Oss®, and the left side was filled with a blood clot. After a healing period of three months, the animals were sacrificed, and the samples were prepared for histological and histomorphometric analyses. The total mineralized area (TMA) as well as the newly formed bone (NBA) was calculated as the percentage of the bone augmentation inside the metallic barriers, and parametric statistical analysis was used to describe the findings. The samples with blood clots exhibited significantly less TMA formation than the Bio-Oss® group. However, the difference in the amount of NBA was not statistically significant. Furthermore, the Bio-Oss® specimens exhibited remaining graft particles within the sample. In conclusion, the barriers filled with Bio-Oss® exhibited significantly higher TMA than those with only blood clots, and the remaining Bio-Oss® particles were integrated into newly formed bone tissue to fill the spaces and promote a greater volume than the samples from the blood clot groups.

Sinus floor augmentation using miniscrew and in situ hardening biomaterial: method and case report

Sinus floor augmentation in case of severe pneumatization is a challenge for surgical management. We present a low invasive endoscopically assisted technique facilitating the stabilization of augmentation material in the subantral space. The technique consists of (1) trepanation of the lateral sinus wall with tunnelling of the sinus membrane and creation of the subantral space, (2) subantroscopically assisted insertion of a mini screw, (3) precise stepwise placement of in situ hardening graft material with antroscopic control. Based on a case example, details of the procedure are presented. The technique provides a minimally invasive treatment for difficult and instable augmentation sites.

Rigid occlusive titanium barriers for alveolar bone augmentation: two reports with 24-month follow-up

Titanium barriers have been used for guided bone regeneration in preclinical and preliminary clinical reports as a possible alternative to bone grafting. In two cases with lateral bone defects, rigid titanium barriers were used to provide a secluded space in conjunction with bone substitutes. Sufficient lateral bone volume was generated for implant placement, and no complications were observed during 2 years of follow up. In conclusion, space-making stiff titanium barriers may be applied successfully for lateral alveolar crest augmentation.

Endoscopically assisted removal of a lingually displaced third molar adjacent to the inferior alveolar nerve

BACKGROUND

Osteotomy of impacted lower third molars still represents a major trauma because of periosteal flap preparation and buccal bone loss. We present a new occlusal flapless approach for the removal of lingually impacted lower third molars adjacent to the inferior alveolar nerve without lateral or lingual osteotomy.

METHOD

After occlusal exposure under local anesthesia, visualization of the third molar region is obtained from a posterior perspective using support endoscopy. Under magnifying endoscopic visualization, the crown is removed using an inward fragmentation technique. After exposure of the furcation area, the roots are separated and removed via the occlusal cavity.

CONCLUSIONS

Endoscopically assisted removal of mandibular third molars allows the maintenance of the adjacent bone structures and the integrity of the mandibular canal. It is valuable in complex anatomic sites in particular.

Coordination of tongue activity during swallowing in mouth-breathing children

Habitual mouth breathing is often accompanied by habitual anterior tongue thrust, instead of a lip closure, in order to create the anterior seal necessary for the initiation of physiological deglutition. We tested the null hypothesis of no significant influence of oral maneuver and the use of oral screens on tongue coordination and position during deglutition in 29 subjects (age = 6-16; mean = 9.69 years; 13/16 female/male) with habitual open-mouth posture using intraoral polysensography. The target parameters for swallowing were swallowing-associated nasal airflow interruption (NAI) and coordination of tongue-palate contact during NAI. Conventional myofunctional maneuvers could be facilitated and made more efficient, in terms of increasing the numbers of favorable early tongue-palate contacts typical of somatic swallowing, if accompanied by the application of an oral screen. Habitual open-mouth breathing does not necessarily coincide with distinctively pronounced proportions of late tongue-palate contact.

An appraisal of the current and potential value of web 2.0 contributions to continuing education in oral implantology

OBJECTIVE

To systematically assess the informational value, quality, intention, source and bias of web 2.0 footage whose aim is peer-to-peer education about oral implantology.

METHODS

YouTube (http://www.youtube.com) was scanned on 15 October 2010 for oral implantology-related videos using an adequately pre-defined search query. Search results were filtered with the system-generated category 'education' and the additional criterion 'most viewed'. Only those videos with at least 1000 views were included (total 124, of which 27 were excluded because they were not related to implantology). Filtered videos were discussed and rated with particular regard to the educational needs of potential groups of addressees [(i) undergraduates and laymen, (ii) dentists without or currently undergoing a specialisation in oral implantology and (iii) dentists who have completed a specialisation in the field of oral implantology] by a jury consisting of (i) an accredited post-graduate university instructor with 22 years of professional teaching experience in the field of implantology, (ii) a university lecturer in dentistry/orthodontics with 10 years teaching experience and (iii) a university haematologist/oncologist. They were required to fill out a questionnaire for each video. The data were statistically analysed using non-parametric ANOVA (α = 5%) and a sign test (α = 0.05/3 = 0.017).

RESULTS

The YouTube scan produced 1710 results in the category 'EDU'. The analysis revealed that there is a wide range of instructional footage on this topic, but with highly variable range in quality and informational value. Footage intention was to large proportions (47.4%) a mixture of education and advertisement. Its usefulness differed significantly for the three groups of addressees, offering greater novelty to undergraduates and post-graduates.

CONCLUSION

YouTube and similar social media websites may have a potential capacity and value in complementing continuing education in the technique of oral implantology. As a means of achieving an acceptable level of knowledge about the topic when used alone, it should not be considered to be suitable at this point in time.

Displacement of dental implants in trabecular bone under a static lateral load in fresh bovine bone

AIM

The study aims to provide objective data for the displacement of titanium screw implants in trabecular bone specimens. One hundred Semados implants (Bego, Bremen, Germany) were inserted in bovine type IV bone specimens. All implants had a diameter of 3.75 mm; 50 implants had a length of 8.5 mm and 50 implants had a length of 15 mm. Insertion torque was determined at intervals of 10, 20, and 30 Ncm. Implants were loaded horizontally with 10, 20, and 30 N for 2 seconds. An indicator strip was attached to the implant abutment to allow direct observation of implant movement relative to the bone surface. Horizontal displacement was assessed with an accuracy of measurement of 10 µm. Seven implants got lost by visible loosening. Degree of displacement was subject to evaluation with all others. Those implants showed a mean displacement of 59 µm for 10 N (n = 100), 173 µm for 20 N (n = 99), and 211 µm for 30 N (n = 93). The mean displacement of 15-mm implants (16, 37, 51 µm) was significantly lower compared with 8.5-mm implants (103, 311, 396 µm) corresponding to 10, 20, and 30 N as lateral loads.

CONCLUSIONS

Displacement of screw implants in trabecular bone can be detected and visualized using commercially available endoscopes with a high magnification. A lateral load of 20 N indicates a mean displacement of over 100 µm and therefore results in a critical displacement.

Tongue position after deglutition in subjects with habitual open-mouth posture under different functional conditions

OBJECTIVE

To test the null hypothesis of no significant differences in (1) the duration of the post-deglutory, cranial tongue rest position (CTP) between different functional orofacial conditions and (2) the presence or absence of an oral screen (OS) in subjects with a habitual open-mouth posture.

SUBJECTS

Twenty-nine subjects (aged 6-16; mean: 9.69 years; 13/16 girls/boys) were selected according to the inclusion criterion of a habitual, daytime open-mouth posture.

METHODS

Deglutition was screened at baseline during resting respiration using orofacial polysensography and simultaneous assessment of tongue-to-palate position and nasal airstream, during five functional intervals of 8 min each: F1 without instruction (RR); F2 the same, but including an oral screen (RROS); F3 with OS and the instruction to maintain a tongue-to-palate contact (IROS); F4 with OS and the instruction to perform tongue repositioning manoeuvres at the time of spontaneous swallowing (TRMOS); and F5 corresponds to F3 omitting OS (IR). Duration and frequency of deglutition were analysed descriptively as well as by anova and subsequent multiple comparisons, and the CTP was evaluated with chi-square tests and paired comparisons at a significance level of 5%.

RESULTS

Of 542 identified swallowing acts, 75% were accompanied by a post-deglutory CTP. Mean duration of CTP increased for functional conditions RR/1.01s > RROS/2.56s > IR/3.21s > IROS/6.53s > TRMOS/6.58s. The null hypothesis (1) was rejected in comparison of resting respiration (F1, F2) with IROS and TRMOS, whereas the use of an oral screen alone did not significantly prolong the duration of CTP.

Intra-oral compartment pressures: a biofunctional model and experimental measurements under different conditions of posture

Oral posture is considered to have a major influence on the development and reoccurrence of malocclusion. A biofunctional model was tested with the null hypotheses that (1) there are no significant differences between pressures during different oral functions and (2) between pressure measurements in different oral compartments in order to substantiate various postural conditions at rest by intra-oral pressure dynamics. Atmospheric pressure monitoring was simultaneously carried out with a digital manometer in the vestibular inter-occlusal space (IOS) and at the palatal vault (sub-palatal space, SPS). Twenty subjects with normal occlusion were evaluated during the open-mouth condition (OC), gently closed lips (semi-open compartment condition, SC), with closed compartments after the generation of a negative pressure (CCN) and swallowing (SW). Pressure curve characteristics were compared between the different measurement phases (OC, SC, CCN, SW) as well as between the two compartments (IOS, SPS) using analysis of variance and Wilcoxon matched-pairs tests adopting a significance level of α = 0.05. Both null hypotheses were rejected. Average pressures (IOS, SPS) in the experimental phases were 0.0, -0.08 (OC); -0.16, -1.0 (SC); -48.79, -81.86 (CCN); and -29.25, -62.51 (SW) mbar. CCN plateau and peak characteristics significantly differed between the two compartments SPS and IOS. These results indicate the formation of two different intra-oral functional anatomical compartments which provide a deeper understanding of orofacial biofunctions and explain previous observations of negative intra-oral pressures at rest.

Functional treatment of snoring based on the tongue-repositioning manoeuvre

Orofacial biofunction comprises muscular and physical effects, which may contribute to stabilization of the oropharyngeal airway. The tongue-repositioning manoeuvre (TRM) provides physical stabilization of the tongue and the soft palate together with, as a prerequisite, a nasal breathing mode. The aim of the present study was to evaluate the influence of a TRM treatment concept on primary snoring. The TRM was used to achieve a closed biofunctional rest position of the orofacial system and to re-educate the nasal breathing pattern. Pressure indicating oral shields were used for home exercises as a biofeedback instrument and to support nocturnal mouth closure. Treatment was undertaken on 125 consecutive primary snorers [101 males, mean age 52.4 years, range 34-75, mean body mass index (BMI) 28.1, range 18.9-38.5, and 24 females, mean age 55.2 years, range 36-70, mean BMI 26.8, range 22.7-31.9]. Bed partner ranking was performed, and snoring was judged using a 10-cm visual analogue scale (VAS). The VAS score was 8.4 (range 6-10) before treatment and decreased to 4.1 (range 0-10) after treatment [mean observation time 4.6 months (1-10)]. Analysis of variance showed a significant influence of treatment in subjects with a normal body weight (BMI 18.5-25). The data provide evidence that dynamic stabilization of the orofacial system with the TRM in conjunction with nocturnal wear of an oral shield is beneficial for reducing the symptoms in primary snorers with a normal BMI.

On the interaction between incisor crown-root morphology and third-order angulation

OBJECTIVE

To evaluate the significance of crown-root angles (CRAs) by testing the null hypothesis that there are no significant differences in deviations of third-order angles to axial inclination values between Angle Class II division 2 incisors and a neutral occlusion control sample.

MATERIALS AND METHODS

The study group comprised n(total) = 130 whites with either Angle Class II division 2 (n(1) = 62; group A) or neutral (n(2) = 68; control group B) occlusal relationships. Upper central incisor inclination (U1) was assessed with reference to the cephalometric lines NA and palatal plane (U1NA/deg, U1PP/deg). Craniofacial sagittal and vertical relations were classified using angles SNA, SNB, ANB, and NSL-PP. Third-order angles were derived from corresponding dental cast pairs using an incisor inclination gauge. Welch's two-sample t-tests (alpha-level: .05) were used to test the null hypothesis. Single linear regression was applied to determine third-order angle values as a function of axial inclination values (U1NA, U1PP) or sagittal craniofacial structures (ANB angle), separately for group A and B.

RESULTS

The discrepancy between axial inclination (U1NA, U1PP) and third-order angles is significantly different (P < .001) between groups A and B. Regression analysis revealed a simply moderate correlation between third-order measurements and axial inclinations or sagittal craniofacial structures.

CONCLUSION

The hypothesis is rejected. The results of this study warn against the use of identical third-order angles irrespective of diminished CRAs typical for Angle Class II division 2 subjects. Routine CRA assessment may be considered in orthodontic treatment planning of Angle Class II division 2 cases.

Flapless implant surgery: an experimental study

OBJECTIVE

The purpose of this study was to examine the effect of flapless implant surgery on crestal bone loss and osseointegration in a canine mandible model.

STUDY DESIGN

In 6 mongrel dogs, bilateral, edentulated, flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants in each side were placed by either flap or flapless procedures. After a healing period of 8 weeks, microcomputerized tomography at the implantation site was performed. Osseointegration was calculated as percentage of implant surface in contact with bone. Additionally, bone height was measured in the peri-implant bone.

RESULTS

The mean osseointegration was greater at flapless sites (70.4%) than at sites with flaps (59.5%) (P < .05). The mean peri-implant bone height was greater at flapless sites (10.1 mm) than at sites with flaps (9.0 mm) (P < .05).

CONCLUSION

Flapless surgery can achieve results superior to surgery with reflected flaps. The specific improvements of this technique include enhanced osseointegration of dental implants and increased bone height.

Flapless sinus floor augmentation using endoscopy combined with CT scan-designed surgical templates: method and report of 6 consecutive cases

PURPOSE

Sinus floor augmentation has become a routine procedure with predictable results. Flapless implant placement is recommended for a series of indications with sufficient bone volume. Flapless surgery in the atrophic maxilla is presented as a refinement of the endoscopic subantroscopic laterobasal sinus floor augmentation (SALSA) technique.

MATERIALS AND METHODS

Based on computerized tomography (CT) scans, the site of sinus trephination and implant positions are planned using a commercially available planning program, and surgical templates are fabricated according to the data of the treatment plan. Subantral space is augmented using the SALSA technique without raising a mucoperiosteal flap. Implants are placed transgingivally without raising a mucoperiosteal flap, with endoscopic control of the cover screw at the bone level.

RESULTS

In a case series of 6 patients, 21 implants were placed and augmented simultaneously. The mean augmentation height was 10.7 mm (range, 5.7 to 16.6 mm); the mean residual bone height was 5.1 mm (range, 1.9 to 12.1 mm). Complications such as insufficient primary stability and sinus membrane perforation were treated without changing to an open surgical approach.

DISCUSSION AND CONCLUSION

Flapless sinus augmentation (FSA) can reduce the surgical trauma significantly. The procedure has high acceptance by the patient and less postoperative discomfort. FSA enlarges the spectrum of minimally invasive surgery and may offer better vascularization and less alveolar resorption.

Immediate Occlusal Loading of Freestanding Implants Using Cortical Satellite Implants: Preliminary Report of a Prospective Study

Freestanding implants with mandibular overdentures are used frequently after 3 months' healing time. Immediate full loading may be applied to this approach if sufficient primary stability is provided. The present study evaluates the success rate of two single-standing interforaminal implants stabilized with cortical satellite implants and loaded immediately with overdentures. Twenty patients (five male and 15 female; age, 45-87 years) received two single-standing titanium screw implants (Semados, Bego, Bremen, Germany). All implants were stabilized during healing time with cortical satellite implants (2.0-mm bone screws; Medartis, Basel, Switzerland) via individual connectors attached to the implant abutment subgingivally. Mandibular overdentures were incorporated immediately after surgery using ball attachments as retentive elements. The patients were under no restrictions concerning diet and loading. The satellite implants were removed after 3 months. All implants were osseointegrated after 10 months' mean observation time. The mean Periotest value was -4.9, and the mean marginal bone loss was 0.7 mm. No dropouts were observed, and 19 of 20 patients would recommend the treatment to a close friend. Preliminary follow-up data indicate that cortical stabilization of two anterior mandibular implants with satellite implants leads to osseointegration of the implants under immediate load conditions with an overdenture. This concept contributes to reduction of prosthetic treatment costs and permits immediate enhancement of masticatory function.

Autotransplantation of immature third molars into edentulous and atrophied jaw sections

The aim of the present study was to assess the results after transplantation of 85 immature third molars. Recipient site conditions varied and different surgical techniques were used. The long-term results after preparation of a new alveolus, splitting osteotomy of the alveolar process or use of free bone autografts were compared with the results after transplantation into a fresh extraction site (control group). Transplantations into prepared sockets showed equal results to the control group (94% respectively). Transplantations in connection with free bone autografts (84%) or after splitting osteotomy of the alveolar process (63%) showed poorer success rates, the differences between the latter and the control group being statistically significant. A possible correlation to revascularization disturbances of the pulp due to an insufficiency of the recipient site or to postoperative infection is suspected. The results show that transplantation of immature third molars is a safe, useful procedure when appropriate conditions of the recipient site are present. Where the alveolus is atrophic, a splitting osteotomy should be performed only in exceptional cases and preference should be given to alternative methods such as primary bone augmentation or bone-regenerative procedures.

In Vitro Evaluation of Horizontal Implant Micromovement in Bone Specimen With Contact Endoscopy

Primary stability of dental implants is mandatory for their osseointegration. A method is described that allows objective measurements of implant displacement in bone sites during lateral loading. Ten samples of bovine bone (2 cm x 2 cm) with bone type II, III, and IV according to Lekholm and Zarb were used for the experiment. Ten Semados dental implants of 15-mm length and 3.75-mm diameter were placed. All implants were loaded with lateral forces of 5, 10, 20, and 30 N through 8-mm abutments for 2 seconds each. Lateral displacement was observed by means of contact endoscopy. Micromovement was detected with the help of a transmitter strip attached to the abutment. Endoscopic images were processed digitally and microdisplacement was calculated relative to the reference body (microscrew) placed adjacent to the implant. Micromovement observed varied with the force applied. Lateral force of 5 N resulted in a mean displacement of 39 microm; for 30 N, the mean displacement was 157 microm. Bone type also influenced the amount of movement. Contact endoscopy represents a new method for direct observation of implant movement relative to the bone surface in vitro. In combination with support immersion technique, contact endoscopy could be used as an office procedure to evaluate intraoperatively implant stability during functional loading.

Subantroscopic laterobasal sinus floor augmentation (SALSA): an up-to-5-year clinical study

PURPOSE

The aim of the article was to introduce a new subantroscopic laterobasal sinus augmentation (SALSA) tecnique as a minimally invasive approach to maxillary peri-implant surgery.

MATERIALS AND METHODS

The SALSA technique consists of the following steps: (1) microsurgical opening of the subantral space (SAS) with detachment of the sinus membrane (SM) under supported videoendoscopy; (2) enlargement of the SAS by laterobasal tunnelling; (3) subantroscopic examination of the SAS with (4) optional reinforcement or repair of the SM; (5) implant site preparation with subantroscopic identification of the cavities; and (6) precise stepwise placement of graft material under endoscopic control.

RESULTS

Since 1996, 118 sinus augmentations have been performed on 83 patients using particulate alloplastic augmentation material (tricalcium phosphate) with various amounts of autogenous bone and blood. Mean augmentation height was 8.6 mm (range, 1 to 15 mm). Twenty-eight perforations of sinus mucosa were observed without further complication (1 case of sinusitis was treated and re-augmented endoscopically). Of 211 titanium screw-type implants placed, 11 failures were observed.

DISCUSSION

SALSA is a predictable surgical technique. With this minimally invasive method, adequate bone height can be achieved.

CONCLUSION

SALSA may offer advantages related to lower morbidity, conservation of bone volume and blood supply, optimized view of the surgical field, and high acceptance by patients.

Real-time endoarticular ultrasound imaging of the TMJ--a new diagnostic possibility? A cadaver study

Recent advances in ultrasound imaging suggested endoarticular ultrasound imaging of the temporomandibular joint (TMJ) in combination with TMJ-arthroscopy as a new diagnostic method. Our investigations were performed on human cadavers, in combination with traditional TMJ-arthroscopy. During our investigations, the main articular structures were identified: the glenoid fossa of the temporal bone, articular disc, condyle of the mandible, and retrodiscal tissue. The combination of arthroscopy and ultrasound imaging provides more information on position, movement, and pathological changes in joint structures. Although all of the advantages, disadvantages, indications, and complications of this new diagnostic procedure are not yet clear, the authors consider this new method a useful diagnostic procedure for TMJ imaging.

[Evaluation of B-scan ultrasound, 3-D ultrasound, roentgen diagnosis and sinus endoscopy in follow-up assessment of the maxillary sinus after sinus floor elevation]

PROBLEM

The aim of this study was to determine which technique--B-scan sonography, 3D sonography, X-ray, or endoscopy--is the most effective for diagnosis in changes of the maxillary sinus after sinus lift and simultaneous augmentation.

MATERIAL AND METHODS

In 33 patients the maxillary sinus was examined before sinus lift, 1 week and 6 months postoperatively with a 7.5-MHz linear scanner and 3D sonography. At the same time, the sonographic results were compared with the X-ray as well as the endoscopic results. Endoscopy of the maxillary sinus was only applied during the sinus lift operation and the abutment operation after 6 months.

RESULTS

A total of 56 operations of sinus lift and simultaneous augmentation with autogenous bone were carried out. Preoperatively, there where no pathological findings detectable in the maxillary sinus. One week postoperatively, the X-rays as well as the sonographic images revealed thickening of the mucosa in 40 maxillary sinuses. After the healing period of 6 months, polyposa was still detected in three cases sonographically, in the radiographic follow-up as well as endoscopically. The sonographic 3D imaging of the maxillary sinus improved the spatial visualization of postoperative changes in the maxillary sinus and the reliability of the diagnosis.

CONCLUSION

Due to the lack of radiation, the cost effectiveness, and its reproducibility, sonography is suitable as a primary screening technique in recall. In cases of normal sonographic findings but clinical symptoms, CT, MRT, and endoscopy should be performed to exclude pathological processes of the posterior maxillary sinus.

Enhancement of primary stability of dental implants using cortical satellite implants

PURPOSE

This study aims to assess the effect of satellite implants on the primary stability of dental implants placed in fresh extraction sites in vitro.

METHOD

34 titanium screw implants (3.75 mm x 10 mm; Bego, Bremen, Germany) were inserted in premolar- and molar-fresh extraction sites in domestic pig mandibles. Periotest (PT) values were assessed before and after insertion of one vestibular and one lingual 1.7-mm bone screw (Mondeal, Tuttlingen, Germany) as a satellite implant was connected to the implants with a 0.6-mm microplate welded to the implant abutment.

RESULTS

The average PT values were 2.9 without satellite implants, -1.0 with one satellite implant, and -2.5 with two satellite implants during horizontal testing, and 3.0, 1.4, and 0.4, respectively, for vertical testing.

CONCLUSION

Satellite implants increase the horizontal stability of implants in fresh extraction sites. Differences for horizontal PT assessment were significant on a 0.01 level of confidence. Implants in extraction sites may be loaded immediately, if vertical stabilization is provided by cortical bone and if horizontal PT values show sufficient stability after satellite implant insertion.

Endoscopic and ultrasonographic evaluation of the maxillary sinus after combined sinus floor augmentation and implant insertion

OBJECTIVE

The aim of our study was a radiographic, endoscopic, and ultrasound follow-up of the maxillary sinus comparing 2 techniques of sinus floor augmentation.

STUDY DESIGN

Sonograms, radiographs (Waters' view) of the sinuses, and endoscopy served before and during surgery to evaluate the maxillary sinus. One week after the operation, ultrasound and radiograph follow-up (Waters' view) were carried out. Six months after the operation, we performed an ultrasound follow-up along with uncovering the implants. If any pathologic condition was found, we took another x-ray film of the sinuses, performed another endoscopic examination, or both.

RESULTS

In 23 of 63 patients, healing was uneventful. Waters' view revealed opacification of the maxillary sinus 1 week after surgery in 40 cases when the "window technique" was used. Sinusitis occurred 3 times, as a result of migration of bone chips in 2 patients. We lost 11 of 132 inserted implants during the healing and loading periods.

CONCLUSION

Endoscope-controlled sinus floor augmentation may lower the complication rate in a remaining height of the jaws between 4 and 8 mm. In our group of patients, we proved by endoscopic examination that migration of cancellous bone sequestra was the reason for sinusitis. In case of infected bone grafts with antral symptoms, sinoscopy allowed debridement and removal of a sequestrum.