Clinical evaluation of patients with temporomandibular joint implants

PURPOSE: An undetermined number of patients with temporomandibular joint (TMJ) symptoms have been treated with intra-articular disc implants composed of Teflon ethylene/propylene or Teflon polytetrafluoroethylene and aluminum oxide (Proplast-Teflon; Vitek, Houston, TX). These implants have shown the potential to fragment in situ resulting in nonbiodegradable particles that stimulate a giant cell reaction and lead to degeneration of local structures, pain, and limitation of mandibular opening. We examined the possible relationship between TMJ implants and persistent pain, responses to sensory stimuli, quality of life, and systemic immune dysfunction. PATIENTS AND METHODS: This case series (32 patients) were referred from university-based orofacial pain centers and private practices from across the United States. Laboratory and clinical assessments evaluated orofacial pain symptoms, neurologic function, clinical signs and symptoms of rheumatologic disease, physical function, systemic measures of immune function, and behavioral measures. RESULTS: We found that TMJ implant patients appeared to have altered sensitivity to sensory stimuli, a higher number of tender points with a diagnosis of fibromyalgia, increased self-report of chemical sensitivity, higher psychologic distress and significantly lower functional ability. Systemic illness or autoimmune disease was not evident in this series of TMJ implant patients. CONCLUSIONS: Significant problems were noted on clinical assessment of TMJ implant patients. This is a US government work. There are no restrictions on its use.     

Performance of Five Commercially Available Tooth Color-Measuring Devices

PURPOSE: Visual tooth color assessment is neither accurate nor precise due to various subjective and objective factors. As newly developed tooth color-measuring devices for dental application provide the possibility of a more objective means of color determination, their performances in vitro and in vivo must be evaluated. The objective of this study was to evaluate the accuracy and precision of five commercially available tooth color-measuring devices in standardized and in clinical environments. MATERIALS AND METHODS: In an in vitro study, standards (A1, A2, A3, A3.5, and A4 shade tabs of Vita Lumin) were measured five times with five electronic devices (ShadeScan, Easyshade, Ikam, IdentaColor II, and ShadeEye) by two operators. In an in vivo study, the right upper central incisors of 25 dental students were measured with the same electronic devices by a single operator. Vita shade tab codes were expressed as CIE (International Commission on Illumination) L*a*b* values and in terms of the precision and accuracy of DeltaE color differences. The Mann-Whitney statistical test was used to analyze the differences between the two operators in the in vitro study, and the Kruskal-Wallis one-way analysis of variance on ranks with the post-hoc Tukey test was used to analyze the accuracy and precision of electronic devices. RESULTS: No statistically significant difference was found between the different operators in the in vitro study. The obtained precision was Easyshade > ShadeScan approximately equal Ikam > IdentaColor II > ShadeEye. The obtained accuracy was Easyshade > ShadeScan approximately equal Ikam > ShadeEye > IdentaColor II. In the in vivo study, the Easyshade and the Ikam were the most precise, and the ShadeEye and the IdentaColor II were more precise than the ShadeScan. With respect to accuracy, there was no statistical difference between the ShadeScan, Ikam, and the Easyshade. The IdentaColor II was considered inaccurate (DeltaE(a)= 3.4). CONCLUSIONS: In the clinical setting, the Easyshade and Ikam systems were the most reliable. The other devices tested were more reliable in vitro than in vivo.     

Primary central adenoid cystic carcinoma of the mandible

An intraosseous adenoid eystic carcinoma occurring within the body of the mandible of a 47-year-old man is described. A radical en bloc Commando's operation was performed. A five-year follow-up showed no local recurrence or distant metastasis.     

Bruxism-induced parotitis: A retrospective case series analysis

ABSTRACT

Objective: A group of patients with recurrent parotitis had clinical symptoms suggesting an obstruction of the glandular duct system, though without any signs of sialoliths or other ductal pathologies.

Methods: Clinical and radiological data of five patients with recurrent obstructive parotitis and long-standing definite bruxism were reviewed retrospectively. Ultrasonography, MRI, and sialendoscopy were performed for evaluation of ductal pathologies as the cause of glandular obstruction. Electromyography was used to evaluate the activity of masticatory muscles in all patients. The parotitis was treated with injection of botulinum toxin into the buccinator muscle.

Results: Dilatation of the Stensen’s duct proximal to the area of the buccinator muscle was shown in radiological examination with no evidence of ductal strictures. Electromyography revealed an abnormal activity of the ipsilateral buccinator muscle. All patients were free of disease after treatment of the buccinator muscle.

Discussion: Bruxism should be considered as a possible cause of recurrent parotitis.     

Does occlusal splint affect posture? A randomized controlled trial

ABSTRACT

Objective

The aim of this study was to evaluate the effect of an occlusal splint on body posture of intra-articular temporomandibular joint (TMJ) disorders patients.     

Do self-curing acrylic resin repairs gain strength with age?

The effect of age on the strength of self-curing acrylic resin repairs has been investigated. Several other properties which may be related were also studied. The findings indicate that the strength of a repair increases with time, attaining a significant proportion of its final strength by 24 hours and reaching a maximum between 1 day and 1 week.     

Structural conformation and leaching from in vitro aged and retrieved Invisalign appliances

The objectives of this study were to investigate the structure of Invisalign appliances (Align Technology, Santa Clara, Calif) after intraoral exposure, and to qualitatively and quantitatively characterize the substances leached from the aligners after accelerated in vitro aging. Samples of Invisalign appliances were randomly selected from 10 patients before intraoral placement and after retrieval, and the prepared specimens were subjected to (1) bright-field optical reflection microscopy to study the surface morphology; (2) Fourier transform infrared microspectroscopy to characterize the in vivo changes in molecular composition induced on appliance surfaces, (3) scanning electron microscopy and energy dispersive X-ray microanalysis to identify the elemental composition of integuments formed on the surface, and (4) Vickers hardness (HV 200) testing. Another set of reference and retrieved appliances was subjected to artificial aging for 2 weeks, and the extracts were subjected to gas chromatography-mass spectroscopy. The retrieved appliances demonstrated substantial morphological variation relative to the as-received specimens involving abrasion at the cusp tips, adsorption of integuments, and localized calcification of the precipitated biofilm at stagnation sites. Buccal segments of retrieved appliances showed an increase in hardness, which might be attributed to mastication-induced cold work; however, the clinical implication of this effect on mechanotherapy is unknown. In vitro aged and retrieved appliances were found to leach no traceable amount of substances in an ethanol aging solution.     

Cartilage formation by serial passaged cultured chondrocytes in a new scaffold: Hybrid 75:25 poly(L-lactide-ε-caprolactone) sponge

PURPOSE: This study was designed to determine whether multipled chondrocytes immersed in a new scaffold, 75:25 poly(L-lactide-epsilon-caprolactone) sponge coated with type I collagen (75-PLC scaffold), could be used to generate cartilage tissue in vivo and to evaluate the correlation between cartilage generation and the phenotype of the proliferated chondrocytes. MATERIALS AND METHODS: Rat chondrocytes were suspended in 75-PLC scaffold at a density of 1 x 10 7 cells/mL after proliferation in a monolayer for 1 (P1) to 4 passages (P4) and implanted in nude mice for 4 weeks. Cells were characterized by the expression of genes encoding type II collagen, aggrecan, and type I collagen by Northern hybridization, and consequently, the newly formed tissue was evaluated histologically. RESULTS: The expression of aggrecan messenger RNA gradually decreased with the passaged cultures; however, the expression of type I collagen messenger RNA increased with time. The cartilage formations in all specimens were found not only in P1 chondrocytes but also in P2 chondrocytes, although when P3 chondrocytes were grafted, approximately 50% of cartilage formation was still observed up to but not beyond P4. CONCLUSION: It is suggested that cartilage tissue is generated with cultured chondrocytes up to P2 but not beyond P4. Northern blot analysis is useful for the assessment of whether the cells are capable of regeneration.