Edge level of aligners and periodontal health: a clinical perspective study in young patients.

INTRODUCTION: Although the superiority of clear aligners over multi-bracket appliances in keeping gingiva healthy has been suggested, the possible benefits of one aligner design over another have not yet been investigated, especially with regard to the vestibular edge. OBJECTIVE: The aim of this study was to measure several periodontal indexes in adolescents undergoing orthodontic treatment with aligners, comparing two different types of rim. METHODS: The study involved 43 patients aged between 14 and 18 years. The periodontal health was assessed using plaque index (PI), gingival index (GI), and gingival bleeding index (GBI), at the start of the treatment with aligners (T0), with a vestibular rim (VR) reaching up to 3 mm beyond the gingival margin. Three months later (T1), aligners were set to obtain a juxtagingival rim (JR) on the second quadrant and VR on the first quadrant. The periodontal indexes were measured again, both at T1 and then three months later (T2). RESULTS: Intra-quadrant comparisons revealed a statistically significant worsening of the periodontal indexes only for the second quadrant (p<0.05), at T1 (GI), and especially at T2 (PI, GI, GBI), while no statistically significant changes were found for the first quadrant. CONCLUSIONS: More severe mechanical irritation, especially during insertion and removal of the aligner, can explain the worsening inflammatory indexes with the JR. In addition, the pressure exerted by the JR on the gingival sulcus seemed to facilitate plaque deposition, whereas the VR had a protective effect, reducing the risk of mechanical trauma.

Edge level of aligners and periodontal health: a clinical perspective study in young patients

ABSTRACT Introduction: Although the superiority of clear aligners over multi-bracket appliances in keeping gingiva healthy has been suggested, the possible benefits of one aligner design over another have not yet been investigated, especially with regard to the vestibular edge. Objective: The aim of this study was to measure several periodontal indexes in adolescents undergoing orthodontic treatment with aligners, comparing two different types of rim. Methods: The study involved 43 patients aged between 14 and 18 years. The periodontal health was assessed using plaque index (PI), gingival index (GI), and gingival bleeding index (GBI), at the start of the treatment with aligners (T0), with a vestibular rim (VR) reaching up to 3 mm beyond the gingival margin. Three months later (T1), aligners were set to obtain a juxtagingival rim (JR) on the second quadrant and VR on the first quadrant. The periodontal indexes were measured again, both at T1 and then three months later (T2). Results: Intra-quadrant comparisons revealed a statistically significant worsening of the periodontal indexes only for the second quadrant (p<0.05), at T1 (GI), and especially at T2 (PI, GI, GBI), while no statistically significant changes were found for the first quadrant. Conclusions: More severe mechanical irritation, especially during insertion and removal of the aligner, can explain the worsening inflammatory indexes with the JR. In addition, the pressure exerted by the JR on the gingival sulcus seemed to facilitate plaque deposition, whereas the VR had a protective effect, reducing the risk of mechanical trauma.

RESUMO Introdução: Embora se alegue uma superioridade dos alinhadores transparentes sobre os aparelhos multibraquetes em manter a gengiva saudável, ainda não foram investigados os possíveis benefícios de um modelo de alinhador sobre outro, especialmente no que diz respeito à borda vestibular. Objetivo: O objetivo deste estudo foi medir vários índices periodontais em adolescentes submetidos a tratamento ortodôntico com alinhadores, comparando dois tipos diferentes de borda. Métodos: O estudo envolveu 43 pacientes com idade entre 14 e 18 anos. A saúde periodontal foi avaliada por meio do índice de placa (IP), índice gengival (IG) e índice de sangramento gengival (ISG), ao início do tratamento com alinhadores (T0), com borda vestibular (BV) estendendo-se até 3 mm além da margem gengival. Três meses depois (T1), os alinhadores foram ajustados para se obter uma borda justagengival (BJ) no segundo quadrante e BV no primeiro quadrante. Os índices periodontais foram medidos novamente tanto em T1 quanto três meses depois (T2). Resultados: As comparações intraquadrantes revelaram uma piora estatisticamente significativa nos índices periodontais apenas para o segundo quadrante (p<0,05), em T1 (IG) e especialmente em T2 (IP, IG, ISG), enquanto nenhuma mudança estatisticamente significativa foi encontrada para o primeiro quadrante. Conclusões: Irritações mecânicas mais intensas, principalmente durante a inserção e remoção do alinhador, podem explicar a piora dos índices inflamatórios com a BJ. Além disso, a pressão exercida pela BJ no sulco gengival pareceu facilitar a deposição de placa, enquanto a BV teve um efeito protetor, reduzindo o risco de trauma mecânico.

Exosomes Derived from Dental Pulp Stem Cells Show Different Angiogenic and Osteogenic Properties in Relation to the Age of the Donor.

Craniofacial tissue reconstruction still represents a challenge in regenerative medicine. Mesenchymal stem cell (MSC)-based tissue engineering strategies have been introduced to enhance bone tissue repair. However, the risk of related complications is limiting their usage. To overcome these drawbacks, exosomes (EXOs) derived from MSCs have been recently proposed as a cell-free alternative to MSCs to direct tissue regeneration. It was hypothesized that there is a correlation between the biological properties of exosomes derived from the dental pulp and the age of the donor. The aim of the study was to investigate the effect of EXOs derived from dental pulp stem cells of permanent teeth (old donor group) or exfoliated deciduous teeth (young donor group) on MSCs cultured in vitro. Proliferation potential was evaluated by doubling time, and commitment ability by gene expression and biochemical quantification for tissue-specific factors. Results showed a well-defined proliferative influence for the younger donor aged group. Similarly, a higher commitment ability was detected in the young group. In conclusion, EXOs could be employed to promote bone regeneration, likely playing an important role in neo-angiogenesis in early healing phases.

Olfactory Dysfunction in COVID-19 Patients Who Do Not Report Olfactory Symptoms: A Pilot Study with Some Suggestions for Dentists.

BACKGROUND: Smell and taste dysfunction are frequently reported by SARS-CoV-2 positive patients. The degree of olfactory and gustatory dysfunction varies from a very mild reduction to their complete loss. Several studies have been performed to determine their prevalence in COVID-19 patients, mostly using subjective measurement methods. The literature lacks long-term studies regarding duration and recovery. METHODS: We assessed olfactory performance, using the Sniffin' Sticks olfactory test, in a group of patients who had not reported olfactory dysfunction, around 131 days after their COVID-19 diagnosis. RESULTS: 11 out of 20 subjects showed no olfactory reduction (65%), while 9 subjects showed reduced TDI score (45%). A total of 13 subjects (65%) scored above the cutoff point for Threshold, 16 subjects (80%) scored above the cutoff point for discrimination and 13 subjects (65%) scored above the cutoff point for identification. CONCLUSION: Objective measurement methods of olfactory performance show a higher prevalence of olfactory reduction compared to patients' self-reported questionnaires. Olfactory dysfunction can last even months after its onset and because of its high prevalence, it could be a screening symptom for suspect COVID-19 cases.

Effect of Water-Based Disinfectants or Air-Drying on Dimensional Changes in a Thermoplastic Orthodontic Aligner.

The polymer structure of thermoplastic materials currently used to make aligners is altered by the oral conditions and this negatively affects their capacity to move teeth. This study aimed to compare different options for storing aligners when not in use by superimposing successive 3D images to identify which storage method least affects material shape and weight. Fifty PET-G aligners, produced using the CA Digital method, were divided into four groups (1A, 1B, 1C, and 2D) and were stored for 18 h a day in artificial saliva at 37 °C. Then, to mimic their storage conditions when not in use, aligners in group 1A were immersed for the remaining 8 hours a day in bicarbonate solution, those in group 1B in chlorhexidine solution, those in group 1C in distilled water, and those in group 2D were stored dry. The samples were scanned at the baseline (before the immersion cycles began) and again two weeks later. The digital scans were superimposed and the median deformation, its variability, and weight differences were recorded for each group. Statistical analysis showed aligner deformation (expansion) in all three groups stored in wet conditions, with a statistically significant difference between groups 1A and 1C. Aligners in group 2D shrank slightly, and to a significantly greater degree with respect to group 1C. Variability in the degree of deformation was similar among the three groups stored in wet conditions, but significantly greater in group 2D. Weight gains were recorded in all four groups, the smallest in group 2D and the largest in group 1A. Storing aligners in dry conditions promoted lower deformation in the material, involving a slight shrinkage, whereas wet storage conditions caused an expansion of the aligner, especially when distilled water is used.

Pregnancy and Dentistry: A Literature Review on Risk Management during Dental Surgical Procedures.

Background: Pregnancy is a unique moment in a woman's life, accompanied with several physiologic changes that have an impact on oral health. Aim of the study: The purpose of the present study was to conduct a critical review of published literature regarding pregnancy and dentistry, the most frequent oral diseases that are encountered during pregnancy, their correlation to adverse pregnancy events, and safe dental treatments that can be performed during pregnancy. Methods: A Medline/COCHRANE search was carried using specific keywords and MeSH terms, combined with the boolean operators "OR" and "AND". Results: The search led to 146 publications including guidelines, meta-analyses, systematic and non-systematic reviews, published between 2000 and 2021. Discussion and conclusions: Due to the increased inflammatory and immune body response that characterizes pregnancy, periodontal conditions are often aggravated during pregnancy and periodontal disease encountered frequently in pregnant patients. There are conflicting study results in the literature regarding the association between periodontitis and adverse pregnancy outcomes. Periodontal treatment did not show a significant reduction in the adverse outcomes. Many dentists, often due to lack of information, are reluctant to provide dental treatment to pregnant women. However, preventive and restorative dental treatment is safe during pregnancy. Diagnostic radiographs may be performed after the first trimester if absolutely necessary. Analgesics (such as paracetamol) and anesthetics (such as lidocaine) are also considered safe. In case of infection, antibacterial drugs such as amoxicillin, ampicillin, and some cephalosporines and macrolides can also be prescribed. Organogenesis takes place in the first trimester, the time during which the fetus is susceptible to severe malformations (teratogenesis). The ideal time to perform dental treatment is the second trimester (week 17 to 28). However, acute pain or infections make the intervention of the dentist absolutely necessary and emergency treatment can be performed during the whole pregnancy period.

Accuracy of 3D digital modeling of dental arches.

OBJECTIVE: The aim of the study was to verify and compare the accuracy of full-arch digital impressions obtained using two intraoral scanners and three scanning methodologies. METHODS: A resin model created with dental 3-D printing was scanned by a reference scanner (Zfx Evolution - Zimmer Biomet, Palm Beach Gardens, FL) in order to obtain a 3D reference; the same resin model was then scanned with two different intraoral scanners (Zfx IntraScan and Carestream 3600 - CS 3600®, Carestream, Rochester, NY, USA) using: Technique A (from tooth #27 up to tooth #17); Technique B (from tooth #11 up to tooth #17 and then from tooth #21 up to tooth #27) and Technique C (from tooth #22 up to tooth #17, and then from tooth #12 up to tooth #27 - the MeshLab software v. 1.3.3 was then used to match the two scans). The scans obtained were superimposed over the reference scan by means of a software, and the volumetric discrepancies were calculated. RESULTS: The mean results for the Zfx Intrascan scanner were: Technique A = 302.47 ± 37.42 µm; Technique B = 180.45 ± 29.86 µm; Technique C = 147.34 ± 28.23 µm. The mean results for the Carestream 3600 scanner were: Technique A = 303.59 ± 40.20 µm; Technique B = 181.53 ± 29.61 µm; Technique C = 142.28 ± 35.33 µm. Technique C, used by both scanners, produced less volumetric discrepancies compared to the other techniques. CONCLUSIONS: The scanning technique had a statistically significant effect on the quality of the scan (p< 0.0001), whereas the scanner did not present any significant influence (p= 0.91).

Accuracy of 3D digital modeling of dental arches

ABSTRACT Objective: The aim of the study was to verify and compare the accuracy of full-arch digital impressions obtained using two intraoral scanners and three scanning methodologies. Methods: A resin model created with dental 3-D printing was scanned by a reference scanner (Zfx Evolution - Zimmer Biomet, Palm Beach Gardens, FL) in order to obtain a 3D reference; the same resin model was then scanned with two different intraoral scanners (Zfx IntraScan and Carestream 3600 - CS 3600®, Carestream, Rochester, NY, USA) using: Technique A (from tooth #27 up to tooth #17); Technique B (from tooth #11 up to tooth #17 and then from tooth #21 up to tooth #27) and Technique C (from tooth #22 up to tooth #17, and then from tooth #12 up to tooth #27 - the MeshLab software v. 1.3.3 was then used to match the two scans). The scans obtained were superimposed over the reference scan by means of a software, and the volumetric discrepancies were calculated. Results: The mean results for the Zfx Intrascan scanner were: Technique A = 302.47 ± 37.42 µm; Technique B = 180.45 ± 29.86 µm; Technique C = 147.34 ± 28.23 µm. The mean results for the Carestream 3600 scanner were: Technique A = 303.59 ± 40.20 µm; Technique B = 181.53 ± 29.61 µm; Technique C = 142.28 ± 35.33 µm. Technique C, used by both scanners, produced less volumetric discrepancies compared to the other techniques. Conclusions: The scanning technique had a statistically significant effect on the quality of the scan (p< 0.0001), whereas the scanner did not present any significant influence (p= 0.91).

RESUMO Objetivo: o objetivo do presente estudo foi verificar e comparar a precisão de modelos digitais de uma arcada dentária completa obtidos utilizando-se dois tipos de scanners e três metodologias de digitalização. Métodos: um modelo de resina feito com impressão 3D foi digitalizado em um scanner de referência (Zfx Evolution - Zimmer Biomet, Palm Beach Gardens, FL) para se obter uma referência em 3D; o mesmo modelo de resina foi, então, digitalizado com dois scanners intrabucais diferentes (Zfx IntraScan e Carestream 3600 - CS 3600®, Carestream, Rochester, NY, EUA) utilizando: Técnica A (do dente #27 ao dente #17); Técnica B (do dente #11 ao dente #17 e, em seguida, do dente #21 ao dente #27); e Técnica C (do dente #22 ao dente #17 e, em seguida, do dente #12 ao dente #27 - osoftware MeshLab v. 1.3.3 foi, então, usado para mesclar as duas leituras). Em seguida, as imagens digitalizadas foram sobrepostas à imagem de referência, utilizando-se um software, e as discrepâncias volumétricas foram calculadas. Resultados: a média dos resultados para o scanner Zfx Intrascan foram: Técnica A = 302,47 ± 37,42 µm; Técnica B = 180,45 ± 29,86 µm; Técnica C = 147,34 ± 28,23 µm. A média dos resultados para o scanner Carestream 3600 foram: Técnica A= 303,59 ± 40,20 µm; Técnica B = 181,53 ± 29,61 µm; Técnica C = 142,28 ± 35,33 µm. A Técnica C, utilizada em ambos os scanners, produziu as menores discrepâncias volumétricas, quando comparada às outras técnicas. Conclusões: a técnica de digitalização teve um efeito estatisticamente significativo sobre a qualidade do modelo digital (p< 0,0001), enquanto o tipo de scanner usado não apresentou qualquer influência significativa (p= 0,91).

Indexes of jaw muscle function in asymptomatic individuals with different occlusal features.

This study aims to assess the correlation between indexes of jaw muscle function and dento-skeletal morphology. A sample of 35 temporomandibular disorders-free healthy individuals (10 males, mean age 26.7 ± 9.8 years) underwent surface electromyographic (sEMG) assessment of bilateral masseter and temporalis muscles, to evaluate sEMG activity during maximum voluntary clenching (MVC) with a dedicated device (Easymyo®, T.F.R. Technology, Udine, Italy). Four outcome parameters were assessed for each individual: MCV on cotton rolls; MVC on teeth; chewing on right and left sides; clench/relax test. Electromyographic recordings were assessed based on five standardized indexes of muscle function, to evaluate the degree of muscle asymmetry during static and dynamic function (i.e., percentage overlapping coefficient [POC], Impact, Asymmetry, Activation, and Torque). For each individual, the presence of a number of occlusal and skeletal features was assessed: asymmetry of molar class; deviated incisor midline; deep bite; open bite; and crossbite. Skeletal class and vertical dimension of occlusion were also evaluated. Based on normality distribution of data, t test and analysis of variance, when needed, were used to compare muscle function indexes between individuals with and without the different dento-skeletal features. None of the muscle function indexes (POC, Impact, Asymmetry, Activation, and Torque) was significantly different between individuals with or without the various dental and skeletal features. Gender differences were also not significant (p > 0.05). Despite some minor differences were observed, none of them was significant. Thus, the interaction between form and function is too complex for hypothesizing a simple one-to-one relationship between interarch tooth relationship and muscle function patterns.

A comparison trial between three treatment modalities for the management of myofascial pain of jaw muscles: A preliminary study.

OBJECTIVES: To compare three treatment modalities for the management of myofascial pain of jaw muscles. METHODS: Thirty (N = 30) patients with low pain-related impairment were randomly assigned to receive laser therapy (LST), oral appliance therapy (OA), or counseling (CSL). Visual Analog Scale (VAS) pain levels and the Muscular Index (MI) of the Craniomandibular Index were the outcome variables, which were assessed at baseline, at three weeks, three months, and six months. RESULTS: At six months, improvement in the MI was maintained both in the LST (p = .025) and OA groups (p < .001). As for VAS values, positive changes were still shown for LST (p = .001), and were also shown for the OA (p = .002) and CSL groups (p = .048). CONCLUSIONS: Despite differences in the short-term effectiveness of LST and OA, with respect to CSL alone, all three treatment groups improved at six months. This suggests that active treatments should be directed to maximize the positive changes in the short-term period.

Breathing parameters associated to two different external nasal dilator strips in endurance athletes.

OBJECTIVE: The aim of the study was to investigate and compare the effects of two different external nasal dilator strips (ENDS) on nasal respiratory flow, maximal oxygen uptake (VO2max), nasal VO2max, time to exhaustion and subjective nasal obstruction in adult triathletes participating in exhaustive, controlled physical exercise tests. METHODS: Thirteen healthy triathletes without nasal symptoms were recruited and randomly tested in three different conditions: without ENDS, wearing the Breathe Right® dilator strip and wearing the Master-aid Roll-flex® strip. We investigated the variations in the peak nasal inspiratory flow (PNIF) and the Nasal Obstruction Symptom Evaluation questionnaire before and after an exhaustive treadmill test. VO2max, nasal VO2max, time to exhaustion, total time of nasal respiration values were also registered and compared. RESULTS: Post-exercise PNIF was higher than the pre-exercise PNIF. Pre-exercise PNIF was higher in athletes wearing the Master-aid Roll-Flex® than in those wearing the Breathe Right® strips; no differences in post-exercise PNIF values were found in the three different conditions. Nasal VO2max value was higher when both types of ENDS were worn. Nasal respiration time to exhaustion was longer when the athletes were wearing either type of ENDS. Both ENDS gave a better sensation of nasal airflow passage after physical exercise. CONCLUSION: ENDS had similar effects, improving the subjective sensation of nasal patency, the nasal respiration time, and the nasal VO2max, anyway Master-aid Roll-flex® is more economic than the Breathe Right® and it can be cut to fit the nasal anatomy. As ENDS affect the cross-sectional area, especially at the level of the nasal valve, in future studies should be conducted also by means of acoustic rhinometry in order to evaluate if any difference could be find at this level when wearing either one of the two ENDS.

Orthodontic treatment of a transposed maxillary canine and first premolar in a young patient with Class III malocclusion.

A 12-year-old girl was referred to our clinic for evaluation of an unaesthetic dental appearance. All permanent teeth were erupted, while the deciduous maxillary right canine was retained. Cone-beam computed tomography revealed a complete transposition of the maxillary left canine and first premolar involving both the crowns and the roots. Initial cephalometric analysis showed a skeletal Class III pattern, with a slight maxillary retrusion and a compensated proclination of the upper incisors. The patient's teeth were considered to be in the correct position; therefore, we decided to attempt treatment by correcting the transposition and using only orthodontic compensation of the skeletal Class III malocclusion. After 25 months of active orthodontic treatment, the patient had a Class I molar and canine relationship on both sides, with ideal overbite and overjet values. Her profile was improved, her lips were competent, and cephalometric evaluation showed acceptable maxillary and mandibular incisor inclinations. The final panoramic radiograph showed that good root parallelism was achieved. Two-year follow-up intraoral photography showed stable results.

Comparison between rapid and mixed maxillary expansion through an assessment of arch changes on dental casts.

BACKGROUND: Aim of this retrospective observational study was to compare upper and lower dental changes in patients treated with Rapid Maxillary Expansion (RME) and Mixed Maxillary Expansion (MME), assessed by dental cast analysis. METHODS: Treatment groups consisted of 42 patients: the RME group (n = 21) consisted of 13 female and 8 male subjects with the mean age of 8.8 years ± 1.37 at T0 and 9.6 years ± 1.45 at T1; the MME group (n = 21) consisted of 12 female and 9 male patients with a mean age of 8.9 years ± 2.34 at T0 and 10.5 years ± 2.08 at T1. The upper and lower arch analysis was performed on four dental bilateral landmarks, on upper and lower casts; also upper and lower arch depths were measured. The groups were compared using independent sample t-test to estimate dental changes in upper and lower arches. RESULTS: Before expansion treatment (T0), the groups were similar for all examined variables (p>0.05). In both RME and MME group, significant increments in all the variables for maxillary and mandibular arch widths were observed after treatment. No significant differences in maxillary and mandibular arch depths were observed at the end of treatment in both groups. An evaluation of the changes after RME and MME (T1) showed statistically significant differences in mandibular arch depth (p<0.001) and maxillary intercanine widths (p<0.05). Differences in maxillary arch depth and arch width measurements were not significant. CONCLUSIONS: RME and MME can be considered two effective treatment options to improve transverse arch dimensions and gain space in the dental arches. A greater lower arch expansion was observed in the MME group, which might be attributed to the "lip bumper effects" observed in the MME protocol.

Surface electromyography findings in unilateral myofascial pain patients: comparison of painful vs. non painful sides.

OBJECTIVES: To answer the clinical research question: in patients with myofascial pain, are there any differences in the surface electromyography (sEMG) activity of muscles of the painful and nonpainful sides that can be detected by commercially available devices? METHODS: The study sample (N = 39; 64% F, mean age 35.7 ± 15 years) consisted of patients seeking for temporomandibular disorders Temporomandibular Disorders (TMD) treatment and meeting Research Diagnostic Criteria for TMD (RDC/TMD) diagnosis of myofascial pain, with pain referred only in muscles on one side. They underwent sEMG of jaw muscles to record levels of standardized sEMG activity at rest, as well as during maximum clenching on teeth for the four investigated muscles, viz., bilateral masseter and temporalis. The existence of differences between sEMG values of muscles of the painful and nonpainful sides during the standardization test (i.e., clenching on cotton rolls) at rest and during clenching on teeth was assessed. RESULTS: At the study population level, differences between the sEMG values of muscles of the painful and nonpainful sides were not significant in any conditions, viz., either at rest or during clenching tasks. At the individual level, the difference between the sEMG activity of painful and nonpainful sides was very variable. CONCLUSIONS: The above findings were not supportive of the existence of any detectable difference in sEMG activity between jaw muscles of the painful and nonpainful sides in patients with unilateral myofascial pain. Centrally mediated mechanism for pain adaptation may explain these findings, and the role of sEMG as a diagnostic tool for muscle pain needs to be carefully reconceptualized.

Denosumab and anti-angiogenetic drug-related osteonecrosis of the jaw: an uncommon but potentially severe disease.

Osteonecrosis of the jaw (ONJ) is a rare but serious lesion of the jaw characterized by exposed necrotic bone and is related to several drugs usually used for treating patients with advanced malignancies. Common therapies inducing ONJ are nitrogen-containing bisphosphonates (BPs), the human monoclonal antibody to the receptor activator of nuclear factor-kappa B ligand denosumab and some anti-angiogenic drugs, alone or in combination with BPs. The real incidence of ONJ is unknown. Several cases of ONJ in patients with cancer who underwent denosumab therapy have been reported and it seems that the overall incidence of denosumab-related ONJ is similar to that for BP-related in this population, ranging between 1-2%. The cell-surface vascular endothelial growth factor (VEGF) receptor plays a major role in cancer progression and can be targeted by drugs inhibiting the tyrosine kinase activator or other second messengers. Most angiogenesis inhibitors, such as the monoclonal antibody bevacizumab and the kinase inhibitor sunitinib, target the VEGF signaling pathway. Unfortunately, cases of bevacizumab-induced ONJ have been reported, especially in patients treated with bevacizumab and BPs in combination. There are only few studies reporting sunitinib-related ONJs. In patients with advanced cancer and malignancy-associated hypercalcemia undergoing BP, denosumab or bevacizumab therapy, enquiry into current dental health and dental examination is mandatory. Good oral hygiene, limiting of alcohol intake and stopping smoking should be suggested for all patients requiring such treatments.

An assessment of the usefulness of jaw kinesiography in monitoring temporomandibular disorders: correlation of treatment-related kinesiographic and pain changes in patients receiving temporomandibular joint injections.

BACKGROUND: The authors conducted a study in patients with temporomandibular joint (TMJ) osteoarthritis to assess whether treatment-related changes in pain levels and chewing ability coincide with a change in jaw kinesiographic (KG) parameters. METHODS: The authors selected 34 patients with a diagnosis of TMJ osteoarthritis that met Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) to undergo a cycle of five weekly arthrocentesis procedures with injections of 1 milliliter hyaluronic acid. They performed a permutation test to assess the correlation between changes across time (from baseline to end of treatment) in two clinical outcome parameters-pain level and chewing ability-and changes across time in the KG outcome parameters. RESULTS: The authors observed improvement across time in both chewing ability (F = 8.328; P = .005) and pain level (F = 10.903; P = .002). The authors observed no significant changes in any KG variables. With minor exceptions, no significant correlations were shown between changes in the clinical and KG parameters during the treatment period. CONCLUSIONS: Treatment-related changes in pain levels and chewing ability in patients with TMJ osteoarthritis do not coincide with changes in KG parameters. PRACTICAL IMPLICATIONS: If one assumes pain variables to be the primary outcome measures in assessing treatment of TMJ osteoarthritis, KG recordings of the jaw are not useful for monitoring TMJ osteoarthritis in the clinical setting.

Kinesiographic recordings of jaw movements are not accurate to detect magnetic resonance-diagnosed temporomandibular joint (TMJ) effusion and disk displacement: findings from a validation study.

OBJECTIVE: The aim of this study was to perform a validation study assessing the correlation between magnetic resonance (MR) findings of temporomandibular joint (TMJ) disk displacement and effusion and some parameters drawn from kinesiographic (KG) recordings of jaw motion, i.e., deflection, deviations, incisures. STUDY DESIGN: Thirty-one patients with TMJ disorders underwent a kinesiographic recording in the same day in which the MR was performed. Regression analysis was performed to assess the correlation between the MR and KG findings. RESULTS: MR findings were not correlated with KG parameters (P > .05). The accuracy of all KG variables for diagnosing MR-detected signs was low. KG deflection ranged from 38.7% to 54.8%, KG deviation from 42% to 54.8%, and KG incisures from 9.6% to 71%. Specificity and positive predictive values were far from acceptable levels for all KG variables. CONCLUSIONS: The findings do not support the usefulness of jaw-tracking devices in dental practices that diagnose and manage temporomandibular disorders.

Age-related differences in temporomandibular disorder diagnoses.

The purpose of the current study was to evaluate the pattern of age distribution of temporomandibular disorders (TMD) and to identify prevalence peaks for the different diagnoses. The study sample (N = 383; F:M ratio = 3.9; mean age range 41.7 +/- 17 years) consisted of patients seeking treatment for TMD and who were assessed in accordance with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) version 1.0 guidelines. The sample was divided into four age groups on the basis of percentile-derived intervals to compare prevalence of different diagnoses in relation to age. The pattern of clinical diagnoses changed with increasing age. The peculiar distribution of RDC/TMD axis I diagnoses, with relation to age, mainly affected the disorders trend of groups II and III, with the former decreasing with age from about 62% to 40% and the latter increasing from 75% to almost 95%. Two distinct age peaks were identified for the prevalence of the main clinical marker of group III diagnosis of arthrosis/arthritis, viz., joint crepitus sounds (N = 104, mean age range 51.9 +/- 14.5), and for the prevalence of all other diagnoses in patients without joint crepitus (N = 279, mean age range 37.9 +/- 16.4). The hypothesis that TMD patient populations may be composed of at least two diagnostic subgroups in relation to age, and that the presence of clinically diagnosed degenerative joint disorders may be a key discriminating factor, was supported. The external validity of the results from this investigation needs to be confirmed by multicenter and cross-cultural studies.