Anterior disk displacement of the temporomandibular joint

Summary In order to examine the diagnostic significance of typical clinical symptoms in temporomandibular joint (TMJ) disorders for diagnosis of anterior disk displacement, clinical findings were compared with the degree of disk displacement in 84 TMJs of 59 patients with TMJ disorders, who were examined clinically and by means of magnetic resonance imaging (MRI). The control group consisted of 31 subjects with no TMJ symptoms. No significant correlation between the degree of anterior disk displacement and palpation pain of the masticatory muscles or clicking/crepitus of the TMJ could be found. Joint clicking was observed in 65% of patients with TMJ symptoms in normal disk position (NDP). The percentage of joint clicking was almost the same in patients with anterior disk displacement with reposition (ADWR) (68%). There were significant correlations between active mouth opening and disk position as well as between a history of pain and disk position. Patients with NDP and ADWR had almost identical mouth opening values: 48 (±5) mm and 46 (±5) mm respectively. In contrast to these groups the mean values decreased significantly to 42 (±6) mm in patients with anterior disk displacement without reposition (ADWOR). There were no significant correlations between occlusal findings (centric relation and habitual relation, early occlusal contacts, abrasion facets) and disk position when viewed either collectively or individually.

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Anteriore Verlagerung des Discus articularis des Kiefergelenkes

Zusammenfassung Zur Überprüfung der Wertigkeit typisch klinischer Symptome für Funktionsstörungen zur Diagnose von Diskusverlagerungen wurden 84 Kiefergelenke von 59 Patienten mit Funktionsstörungen und 31 Kiefergelenke von klinisch asymptomatischen Probanden mittels Magnetresonanztomographie (MRT) untersucht und die einzelnen klinischen Befunde der Art der Diskusvergerung gegenübergestellt. Zwischen dem Grad der anterioren Diskusverlagerung und einem positiven Palpationsbefund der Kaumuskulatur, einem Palpationsschmerz der Kiefergelenke und dem Auftreten von Gelenkgeräuschen ergaben sich keine signifikanten Beziehungen. Bei funktionsgestörten Patienten zeigte sich mit 65% bei normaler Diskusposition (NDP) fast ebenso oft ein Gelenkknacken wie bei Patienten mit anteriorer Diskusverlagerung mit Reposition (VMR, 68%). Signifikante Beziehungen bestanden zwischen aktiver Mundöffnung und Diskusposition sowie anamnestisch angegebenen Schmerzen und Diskusposition. Während bei NDP- und VMR-Patienten mit 48 (±5) mm und 46 (±5) mm ähnlich hohe Mundöffnungswerte vorlagen, nahmen diese bei Patienten mit anteriorer Diskusverlagerung ohne Reposition (VOR) auf 42 (±6) mm signifikant ab. Okklusale Befunde (Differenz zwischen zentrischer und habitueller Okklusion >2 mm, vorzeitige okklusale Kontakte, Auftreten von Schliffacetten) zeigten in ihrer Gesamtheit wie auch in der Einzelbetrachtung keine signifikanten Beziehungen zur Diskusposition. Die Ergebnisse zeigen, daß für die Diagnostik von Funktionsstörungen allgemein als bedeutend anerkannte klinische Symptome in bezug auf die Art und das Vorliegen einer anterioren Diskusverlagerung allein keine sichere Aussage zulassen. Dies betrifft besonders die anteriore Diskusverlagerung ohne Reposition. Gleichzeitig wird die Zuverlässigkeit der MRT für die klinisch oft schwierige Diagnostik der Bestimmung der Diskusverlagerung bei Patienten mit Funktionsstörungen des Kausystems bestätigt.

     

Artificial periodontal defects around incisor teeth of beagle dogs

The aim of the present experiment was to investigate if it is possible to create deep periodontal defects around incisor teeth of beagle dogs with the use of orthodontic elastic bands, to investigate if this method is reproducible and predictable, and to evaluate if such defects possess the histopathological characteristics of naturally occurring periodontitis. In eight beagle dogs the dentogingival fibres around four upper incisors, ³I₃ and ²I₂, were cut to the level of the alveolar bone. Orthodontic elastic bands were placed in these deepened sulci and removed after 8 weeks. Clinical data (probing depth and gingival recession) were recorded at the start of the experiment, immediately following removal of the elastic bands, and 2, 6, 14, and 30 weeks thereafter. The dogs were sacrificed on different dates so that is was possible to analyse defects histometrically 3, 7, 15, or 31 weeks after elastic removal. Contralateral defects one week after elastic band removal served as controls. Micrographic color slides of the histological sections were analysed using a Ferranti-Cetec digitizer. Immediately after elastic band removal mean values for probing depth and gingival recession were approximately 5.5 mm and 2.0 mm, respectively. Histometrical assessments revealed a loss of attachment of approximately 3.0 mm. The differences in probing depths between Contralateral defects in the same dog were small indicating rather high reproducibility of the method. Because of wide variations in probing depth and histometrical dimensions between dogs, it was concluded that the present method is not fully predictable. Upon elastic removal values for probing depth decreased with approximately 1.5 mm, the result being a moderately deep defect of around 4 mm. Histometrically there was no evidence that the apical positioning of the junctional epithelium was reversible after elastic removal. However, alveolar bone repair could be demonstrated in the 7, 15, and 31 weeks specimens. It was concluded that because of this bone repair, the present defects do not possess all histopathological characteristics of naturally occurring periodontitis.     

Characterization of root surface periodontal ligament following avulsion, severe intrusion or extraction: preliminary observations

Abstract –  This study employed novel topographic and histological techniques to assess remaining periodontal ligament (PDL) in a convenience sample of avulsed and intruded human permanent incisors and extracted premolars. Seventeen human teeth (eight avulsed, five severely intruded and four uninjured extracted) were evaluated for the distribution and physical characteristics of adherent root surface PDL. The topographic distribution of PDL was assessed by staining roots with malachite green and determining the proportion of remaining PDL within selected regions on four aspects of each tooth. In order to characterize mechanical damage to PDL, serial transverse sections of roots were stained with hematoxylin and eosin and examined at magnifications of 40× to 800×. The sections were photographed and imaging software was used to calculate the percentage of remaining PDL in the circumference of each root section. Topographic analysis demonstrated that 54% of the PDL remained on roots of avulsed and severely intruded incisors and 36% of the PDL remained on the extracted single-rooted premolars. Examination of serial transverse root sections revealed that 58% of the PDL remained on roots of avulsed or severely intruded incisors and 54% on extracted premolars. Avulsed and severely intruded incisors demonstrated similar amounts of retained PDL. In both injuries, almost half of the root surface was denuded of PDL.     

Überlebensverbesserung eines unizentrischen Gesamtkollektivs aus 20 Jahren

Purpose

The development of overall survival of a DÖSAK (German-Austrian-Swiss Cooperative Group on tumours of the maxillofacial region) clinic’s overall population comprising a time period of more than 20 years (1983–2004) should be assessed. At a cutoff date (January 1st, 1997), a change from a primarily surgically based to a consequent multi-modality treatment regimen was implemented. The periods of time before and after that change should be compared.

Methods and patients

The data of the DÖSAK registry entries on 1038 patients suffering from primary untreated oral and oropharyngeal carcinomas were updated with respect to follow-up and mortality data to achieve a 100% quality of follow-up. The end point (death) was reached in 67% of the overall population. Statistical analysis was carried out by the Trium Analysis Online corporation, Munich.

Results

The portion of female and older tumor patients increased, more than half of all tumor patients were clearly in stage IV of the disease at first referral. The portion of patients operated on persisted approximately (80%), the portion of additional treatment modalities could be increased considerably. The fact of a bony infiltration by the tumor and the operability remained highly significantly relevant for survival in multivariate analysis, despite of multi-modality treatment. The survival rate of the patients remained significantly dependent on the clinical stage of the disease in multivariate analysis but could be improved by 10% in the clinical stages II and III and in the patients who could not be operated on. All in all, the cutoff date was statistically relevant for survival in multivariate analysis, i.?e. the change in the treatment regimen had a verifiable positive effect on the survival of a unicentric overall population.

Conclusion

Survival improvement in an overall population via change in treatment strategy is possible in relatively short time; the clinical stages II and III and the non-operable patients have the greatest benefit from a multi-modality treatment.     

The smallpox vaccine: An update for oral health care professionals

BACKGROUND: A heightened awareness of the potential for bioterrorist attacks in the United States has led to the expansion of the nation's supply of smallpox vaccine and the institution of procedures to distribute this vaccine in the unlikely event of a release of this potentially deadly agent. METHODS: The authors conducted a review of the relevant smallpox literature through a MEDLINE search. They also reviewed the Web site of the Centers for Disease Control and Prevention and numerous other Web sites. RESULTS: The authors considered for inclusion more than 100 articles discussing smallpox, the smallpox vaccine and the role of the dental professional in a bioterrorist attack. CONCLUSIONS: Dentists may detect the initial signs of a smallpox infection, provide information concerning the disease to the public and potentially assist in the administration of smallpox vaccine. CLINICAL IMPLICATIONS: Should an intentional release of smallpox occur, the dental professional may play an important role in its treatment and prevention.     

Thickness of the anterior maxillary facial bone wall-a retrospective radiographic study using cone beam computed tomography

The purpose of this retrospective radiographic study was to analyze the thickness of the facial bone wall at teeth in the anterior maxilla based on cone beam computed tomography (CBCT) images, since this anatomical structure is important for the selection of an appropriate treatment approach in patients undergoing postextraction implant placement. A total of 125 CBCT scans met the inclusion criteria, resulting in a sample size of 498 teeth. The thickness of the facial bone wall in the respective sagittal scans was measured perpendicular to the long axis of the tooth at two locations: at the crest level (4 mm apical to the cementoenamel junction; MP1) and at the middle of the root (MP2). No existing bone wall was found in 25.7% of all teeth at MP1 and in 10.0% at MP2. The majority of the examined teeth exhibited a thin facial bone wall (< 1 mm; 62.9% at MP1, 80.1% at MP2). A thick bone wall (? 1 mm) was found in only 11.4% of all examined teeth at MP1 and 9.8% at MP2. There was a statistically significant decrease in facial bone wall thickness from the first premolars to the central incisors. The facial bone wall in the crestal area of teeth in the anterior maxilla was either missing or thin in roughly 90.0% of patients. Both a missing and thin facial wall require simultaneous contour augmentation at implant placement because of the well-documented bone resorption that occurs at a thin facial bone wall following tooth extraction. Consequently, radiographic analysis of the facial bone wall using CBCT prior to extraction is recommended for selection of the appropriate treatment approach.     

Influence of impression material and time on the 3-dimensional accuracy of implant impressions.

OBJECTIVE: To investigate, in vitro, the effect of time on the 3-dimensional accuracy of open-tray implant impression copings made of polyvinyl siloxane and polyether impression materials. METHOD AND MATERIALS: Reference models with 4 internal connection implants were fabricated. Four sets of 71 direct impressions were made with square impression copings using an open-tray technique. One set of impressions was made with polyether material (material A) and each of 3 polyvinyl siloxane materials (materials B, C, and D). Three-dimensional changes in spatial orientation of the implant analogs were measured over 48 hours using an optical measurement device. Deviation values were summed over 4 points and averaged per impression. Global differences were tested with a nonparametric Kruskal-Wallis test followed by pairwise comparisons using the Mann-Whitney U test. RESULTS: The mean dimensional accuracy of implant impressions significantly differed over time (P < .001). Materials A and B were found to produce comparable results, For materials C and D there was a significant increase in deviations, with a maximum increase at 2 hours. Deviations for material C were comparable to materials A and B at 48 hours. Baseline values were not maintained by any material. CONCLUSIONS: Within the limits of this in vitro study, it can be concluded that time cannot be neglected as a factor affecting the accuracy of implant master casts.     

PBL core skills faculty development workshop 1: An experiential exercise with the PBL process

This report describes the first in a series of foundation-building faculty development workshops focused on the instructional methodology of problem-based learning (PBL). The PBL Process workshop reported here introduced the learning theory topics supporting PBL and utilized an extended roleplay method to provide participants with personal experience with the PBL learning cycle. Overall, participants were satisfied with the methods and content of the workshop. A majority of survey respondents indicated that simulating a complete iteration of the PBL process was an effective way to learn about PBL. Participants expressed relatively greater difficulty understanding and performing activities related to qualitative assessment of learning processes. The workshop was developed to align with adult learning principles, and continued refinement of the workshop has enhanced the learning theory components underpinning PBL as well as the experiential aspects. These dual goals have resulted in blending the existing experiential workshop with an online distance-learning component addressing the learning theory topics relevant to PBL pedagogy.     

Reconstruction of the temporal contour for traumatic tissue loss using a CAD/CAM-prefabricated titanium implant-case report

INTRODUCTION: A 16-year-old Arab boy had suffered from a severe head injury including an intracranial haematoma. Despite replantation of the bone flap later on, the cosmetic result was very unfavourable due to partial resorption of the reinserted bone and atrophy of the right temporalis muscle. AIM: For contour reconstruction of both soft and hard tissues the boy was transferred from Saudi Arabia. METHOD: A spiral CT was obtained and the contour was reconstructed using a new algorithm for surface generation. RESULT: The resulting titanium implant was inserted without complications or the need for revision. The cosmetic result was good and corresponded to the preoperative digital planning. CONCLUSION: Techniques of computer-assisted implant prefabrication and surgery may include special algorithms for considering soft tissues including contour deficits of the temporalis muscle.     

Glomus tumor of the index finger

A 41-year-old female patient presented with localized worsening subungual pain of her right index finger. Subsequent diagnostic evaluation revealed the presence of a glomus tumor. A glomus tumor is a rare tumor with a predilection for the hand. Classic symptoms include pain, pain with pressure, and pain with cold temperature. We present a completely updated literature review that addresses the epidemiology, pathology, presentation, diagnostic evaluation, classification, histology, genetics, and treatment options for glomus tumors.