Transferring the tooth preparation finish line on intraoral digital scans to dental software programs: A dental technique.

Intraoral scanner software programs allow the clinician to draw the tooth preparation finish lines. However, this information may be lost when importing the digital file into different computer-aided design (CAD) dental software programs. A technique for transferring the marked tooth preparation finish line into an intraoral digital scan is described. The intraoral digital scan of the tooth preparation is duplicated and used to draw the finish line. Subsequently, the tooth preparation geometry is erased while maintaining the finish line border, which will be used as a reference when designing the definitive restoration in the CAD software program.

Impact of photodynamic therapy versus ultrasonic scaler on gingival health during treatment with orthodontic fixed appliances.

OBJECTIVES: Poor oral hygiene during treatment with fixed appliances results in plaque accumulation. The presence of bacteria in the gingival crevice triggers an inflammatory reaction in the gingival tissues. The aim of this study was to compare the impact of two preventive treatments, photodynamic therapy (PDT), and ultrasonic scaler (US), on gingival health in patients under fixed orthodontic treatment. METHODS: Twenty orthodontic patients were randomly allocated to two groups: PDT or US. Each group received seven sessions [days 0, 15, 30, 45, 90 (3-months follow-up), 180 (6-months follow-up), 270 (9-months follow-up)] of experimental interventions, and clinical parameters [Plaque index(PI); gingival index(GI); probing depth(PD)], periodontopathogens [Agreggatibacter actinomycetemcomitans; Porphyromonas gingivalis; Prevotella intermedia; Micromonas micros; Fusobacterium nucleatum; Tannerella forsythia; Campylobacter rectus; Eikenella corrodens; Capnocytopaga sp.] and protein markers [IL-1ß;IL-1ra;IL-6;IL-10;TNF-α;FGF-2/FGF basic] were monitored at baseline and at 3, 6, and 9 months. ANOVA, Student's t-test with Bonferroni correction and ANOVA with multiple rank test were used to identify differences between groups (P < 0.05). RESULTS: Clinical assessments [PI, GI, and PD] yielded no differences (P > 0.05) between groups, which showed a major decrease at the start of the trial. Reductions in total colony forming units (log CFU reduction) were observed with both treatments, although to a greater extent in the PDT group, but with no differences between groups (P > 0.05). Similar reductions in log CFU counts of P. gingivalis, P. intermedia, and F. nucleatum were observed in both groups (P > 0.05). The two groups also showed similar trends for inflammatory mediators with decreased levels of IL-1ß, IL-10, and TNF-α, whereas IL-6 and IL-1ra levels remained stable and those of FGF-2 were increased after both interventions, with no differences (P > 0.05) between groups. CONCLUSION: Both PDT and US methods proved similar effectiveness for the treatment of gingival inflammation induced by fixed orthodontic appliances. Lasers Surg. Med. 51:256-267, 2019. © 2018 Wiley Periodicals, Inc.

Clinical and microbiological effects of the use of a cetylpyridinium chloride dentifrice and mouth rinse in orthodontic patients: a 3-month randomized clinical trial.

Objective: To assess the clinical, microbiological, and patient-based effects of using a cetylpyridinium chloride (CPC) toothpaste and mouth rinse in orthodontic patients. Design: Parallel randomized controlled, triple-blinded trial (participants, examiners, outcomes' assessors). A computer-generated list was used to allocate treatments. Central allocation was used for concealment. Participants: Thirty-one placebo (10 males, 21 females; mean age 15.2 ± 2.1) and 32 test patients (15 males, 17 females; mean age 15.0 ± 1.8) with fixed orthodontic appliance were included in the study. Interventions: Patients were randomly assigned to both brush and rinse with placebo or with CPC-based products. Products were purposely prepared in white opaque bottles. After screening and professional prophylaxis, patients received a baseline examination, and started to use the assigned products. Patients were monthly assessed during a 3-month period. Main outcome measures: Plaque (PlI) and gingival (GI) indexes. Secondary outcome variables: Calculus index, tooth staining, subgingival microbiological samples, patient-based variables (questionnaire, compliance, and remaining mouth rinse), side-effects (debonded braces or mucosal injuries). Results: Sixty-three patients were randomized, 13 patients were excluded from analysis because of early dropout, leaving 50 patients for intention to treat analysis. PlI in the upper jaw diminished (0.18; SD = 0.82) after 1 month in the test group, while it increased (0.26; SD = 0.62) in the placebo group (P = 0.024). Statistically significant higher GI values were observed in the placebo group at 1 month (mean increase = 0.05; SD = 0.33 versus mean decrease = 0.03; SD = 0.38) and 3 months (mean = 0.05; SD = 0.43 versus mean = 0.02; SD = 0.34). The taste of the test product was rated higher than the placebo at 2- and 3-month visits (P < 0.05). Non-significant changes were observed in microbiological parameters, overgrowth of opportunistic species or remaining secondary outcome variables, including side-effects. Conclusion: The use of CPC-based toothpaste and mouth rinse in orthodontic patients had limited effect in reducing plaque accumulation and gingival inflammation. Effects were little and highly variable. The use of the test products was not associated with relevant adverse effects. Trial registration: Trial registration: Local internal reference: P07/133.

Effects of low-level laser therapy on orthodontics: rate of tooth movement, pain, and release of RANKL and OPG in GCF.

The aim of the study was evaluate tooth movement, receptor activator of nuclear factor KB ligand (RANKL), osteoprotegerin (OPG), and RANKL/OPG ratio in gingival crevicular fluid (GCF) in compression side and pain level during initial orthodontic tooth treatment to determine the efficacy of low-level laser therapy (LLLT). Ten volunteers who required fixed appliance positioned from the upper first premolars to upper first molars were selected. For each patient, the upper first premolar of the quadrant 1 was chosen to be irradiated with a laser diode at 670 nm, 200 mW, and 6.37 W/cm(2), applied on the distal, buccal, and lingual sides during 9 min on days 0, 1, 2, 3, 4, and 7. The same procedure was applied in the first premolar of the contralateral quadrant inserting the tip but without laser emission. Samples of GCF from the compression side of the upper first premolars to distalize were collected at baseline and after 2, 7, 30, and 45 days posttreatment for determination of RANKL and OPG by enzyme-linked immunosorbent assay. In addition, tooth movement was assessed by scanning models and pain intensity was assessed using a visual analog scale. There was improvement in the parameters studied (pain, tooth movement, levels of RANKL in GCF, and RANKL/OPG ratio) in the laser group when compared to the control group, although differences were not statistically significant. The accumulated retraction of the upper premolar at 30 days was higher in the laser group, and this difference was statistically significant between groups. LLLT delivered in repeated doses (six times in the initial 2 weeks) leads in some extent to a slight orthodontical improvement.

Gamma Knife radiosurgery for the management of glomus jugulare tumors: A systematic review and report of the experience of a radioneurosurgery unit in Latin America.

Background: Glomus jugulare tumors (GJTs) are rare and mainly affect women between the 5th and 6th decades of life. Its localization and anatomic relationships make conventional surgical treatment difficult and with a considerable risk of complications. This manuscript aims to describe the results of Gamma Knife radiosurgery (GKR) in patients with GJT treated in a single center in Latin America, as well as to systematically review the literature to determine the clinical and radiological effectiveness of this technique. Methods: A search of information from January 1995 to June 2023 was performed. Twenty-two articles reporting 721 GJT patients treated with GKR were included in the study. Variables such as symptomatic control, control of tumor size, and complications were evaluated. These variables were described using measures of central tendency and proportions. For the institutional experience, 77 patients with GJT tumors were included in the study. Pre-treatment clinical variables and follow-up data were collected from medical charts and phone interviews. The Short Form-36 scale was applied to assess the quality of life. The data were analyzed using the statistical program STATA17.0. Results: A total of 721 patients were considered. The median of patients included in these studies was 18.5. The mean age was 58.4 years. The median of symptom control was 89%, and the median of imaging control was 95.7%. In our institution, 77 patients were included in the study. The mean age was 53.2 years. The median hospital stay was 4.92 hours. For the clinical follow-up, information on 47 patients was obtained. An improvement in pre-treatment symptoms was described in 58%, with general symptomatic control of 97%. The tumor-control rate was 95%, and there were statistically significant differences in six of the nine Short Form-36 scale domains. Conclusion: GKR is an effective, safe, and cost-effective technique that offers a high degree of symptomatic and tumor size control in patients with GJT.

Gamma Knife radiosurgery - 12 years of experience in a high-complexity center of a middle-income country.

Background: Gamma Knife radiosurgery (GKR) is a technique that consists of the release of a high dose of ionizing radiation onto a therapeutic target, which has been previously delimited. This technique was described by Lars Leksell and Borje Larsson in 1951. In Colombia, there is only one GKR unit functioning machine nowadays. The objective of this study is to describe the institutional experience of a single institution with Gamma Knife Perfexion over 12 years. Methods: We conducted a retrospective observational study. A total of 1906 medical records, taken from the period between May 4, 2010, and May 4, 2022, were included in the study. Descriptive analysis was performed through STATA 17 as statistic tool. Measures of central tendency were calculated depending on the distribution of the continuous data and proportions were taken into account in the case of qualitative variables. Results: A total of 1906 procedures were performed. Patients from 1 year to 99 years old were treated, with a median age of 51 years. The most frequent diagnoses were meningioma (20.8%), arteriovenous malformation (AVM) (17%), vestibular schwannoma (15.6%), metastases (9.81%), and trigeminal neuralgia (9.12%). At 3-year posttreatment, in meningiomas, tumor size stability was observed in 57.3%, size decrease in 36%, and disappearance in 1.3%. In AVM, complete obliteration of the lesion was described in 36.8% and a decrease in size in 52.6%. Intracranial hemorrhage occurred in 5.2% during the follow-up period and 3.5% of all treated patients required a new procedure due to residual malformation. In vestibular schwannomas, tumor size remained stable in 62.2% and decreased in 28.8%. No new cases of facial paralysis after the procedure were described. At 1-year posttreatment, in metastasis, the size of the lesions remained stable in 40% of the patients, decreased in 47.5%, and disappeared in 2.5%. In trigeminal neuralgia, 88.4% of patients had pain relief and recurrences occurred in 16.6%. Acute complications were generally uncommon, the main ones being headache, pain at frame fixation points, and nausea. Conclusion: Our experience suggests that GKR is a noninvasive procedure with a broad spectrum of clinical applications, low frequency of complications, feasible, with good enough control size of tumor and vascular lesions in images, and good clinical results in the medium and long term.

Effects of Photobiomodulation on the Upper First Molar Intrusion Movement Using Mini-Screws Anchorage: A Randomized Controlled Trial.

Objective: The aim of this study was to quantify the changes obtained when the molar intrusion movement is complemented by photobiomodulation (PBM). Background: A common problem in adult patients is the super-eruption of maxillary molars caused by the loss of the antagonist tooth. Super-erupted molars impair oral rehabilitation and can cause both occlusal and functional problems. There is increasing research confirming the benefits of adjunctive PBM during orthodontic treatment. Methods: Twenty patients with indication of a maxillary first molar intrusion for oral rehabilitation were selected. Patients were randomized into two groups to receive orthodontic intrusion (control group) or the same treatment complemented by PBM (PBM group) in repeated doses (days 0, 1, 2, 3, 4, and 7 from the start of the intrusion and in each monthly follow-up) by using a low-power red laser diode (670 nm, 150 mW, 12 min around the molar). Plaque index (PI), probing depth (PD), and bleeding of probing (BOP) were assessed at 0, 1, 2, 3, and 6 months. Stereolithography models generated from an intraoral scanner were taken at 0, 3, and 6 months and cone beam computed tomography (CBCT) records were taken at 0 and 6 months. Mean intrusion distance, mean intrusion velocity, and volumetric resorption were calculated. Results: Periodontal clinical assessments (PI, PD, and BOP) and mean intrusion distance or mean intrusion velocity yielded no differences (p > 0.05) between groups. However, PBM group showed lower values of all these scores during the first 3 months. Intraoral scanner and CBCT were equally effective in accurately monitoring the intrusion distance (p > 0.05). CBCT records allowed volumetric evaluation of the root resorption process, being lesser in the PBM group, but not significantly (p > 0.05). Conclusions: During orthodontic intrusion process, the adjunctive application of PBM may provide better periodontal records and lower progression of root resorption at the expense of a little lower intrusion distance and velocity.

A new concept of anatomic lingual arch form.

INTRODUCTION: The aim of this study was to describe a natural and anatomic lingual arch form obtained from subjects with normal occlusion that could be used, with other criteria, in the construction of personalized setups for the lingual straight-wire technique. METHODS: The study sample comprised 58 pairs of dental casts of the arches of 58 southern Europeans (37 women, 21 men) with ideal natural occlusions. After the reference points of the dental arches were identified and marked, the dental casts were scanned. The exact position of the models on the scanner was established by using an acetate sheet with a Cartesian reference system. For each image, 14 reference points (x, y) were measured and recorded. The measurements were processed with software to select the polynomial function that best described the shape of the dental arches. The ninth-degree polynomial function was selected to represent the lingual arch form of both arches. Distribution analysis of the x and y values of each tooth in each arch resulted in the creation of 3 groups (small, medium, and large) to verify the most appropriate measures of the central tendencies of our data. RESULTS: Statistical analysis showed no significant sex difference in the medians of the 6 parameters used to measure depth and width in both arches. A representation of the variability of the lingual curve of our sample was created to document at least 3 sizes of the representative curve of the central tendency for our data. No statistically significant differences in shape were found between men and women, considering the medians as a measure of the central tendencies. CONCLUSIONS: Three lingual curves (small, medium, and large) for the maxillary and mandibular arches, representing the mean values of our sample, were developed and can be used as guides for the setup in the lingual straight-wire technique.

Efficacy of photodynamic therapy vs ultrasonic scaler for preventing gingival inflammation and white spot lesions during orthodontic treatment.

INTRODUCTION: The complex designs of fixed orthodontic appliances hinder proper access for cleaning, favouring the development of gingival inflammation and white spot lesions around brackets. The aim of this study was to evaluate the effectiveness to avoid these undesirable effects by using two prophylactic methods: Photodynamic Therapy (PDT) and conventional ultrasonic scaler (US), in patients during fixed orthodontic treatment. MATERIALS AND METHODS: Twenty patients under orthodontic treatment for at least 15 months were randomly divided into two groups: PDT mediated by methylene blue (MB) and US. Both treatments were applied in repeated doses (four times in intervals of 2 weeks in the beginning of the study (T0), with booster doses at 3, 6 and 9 months, T1, T2 and T3, respectively). Periodontal clinical parameters (full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS) and probing depth (PD)) were recorded as well as the International Caries Detection and Assessment System (ICDAS) index. Samples of subgingival plaque and saliva (for determination of 4 periodontopathogens and mutans streptococci, respectively), were collected at T0 and at the follow-ups of T1, T2 and T3. RESULTS: The evolution of FMPS, FMBS, PD, ICDAS scores as well as the counts of periodontopathogens and salivary mutans streptococci was similar after US or PDT implementation. Greatest periodontal scores reduction took place at T1 for FMBS and PD and at T2 for FMPS. Main microbial reduction took place at T1. ICDAS index began to increase from T2. No statistically significant intergroup differences were observed. CONCLUSIONS: Additional treatment of PDT or US in repeated doses delayed undesired side effects during fixed orthodontic treatment in young patients with low caries risk and signs of gingival inflammation.

[Risk factor control and treatment of atherothrombosis. Spain REACH Registry]. / Control de factores de riesgo y tratamiento de la aterotrombosis. Registro REACH España.

BACKGROUND AND OBJECTIVE: The REACH Registry is the largest worldwide registry designed to obtain information on cardiovascular risk factor control and preventive treatment in a population who have, or are at high risk of having, symptoms of atherothrombosis. The objective of this study is to show the results obtained in a sample of the Spanish population included in that registry. PATIENTS AND METHOD: Registry of consecutive patients who have risk factors only (RFO) for atherothrombosis or who have symptomatic vascular disease (VD): coronary heart disease (CHD) and/or cerebrovascular disease (CVD) and/or peripheral artery disease (PAD). Cardiovascular risk factor control and the use of antithrombotic and lipid lowering therapy were evaluated. RESULTS: In Spain 2,515 patients were recruited; 297 had RFO and 2,218 had VD: 61.4% with CHD, 36.6% with CVD and 18.7% with PAD. The rates of noncontrolled blood pressure, glycemia, total cholesterol and triglyceride levels in the RFO group compared to those of the VD group were: 76.5% vs 57.1% (p < 0.005), 61.6% vs 30.9% (p < 0.005), 55.7% vs 41.3% (p < 0.005) and 45.5% vs 35.1% (p < 0.005), respectively. The antiplatelet therapy rate in these two groups was 44.1% vs 86.5% (p < 0.005), the anticoagulant therapy rate was 11.4% vs 12.6% (no significant difference) and statin therapy rate was 65.2% vs 65.6% (no significant difference). Significant differences were found among the CHD, CVD and PAD groups as regards noncontrolled blood pressure rate (49.8%. 57.1% and 67.1%, respectively p < 0.005), total cholesterol control rate (41.3%, 48.2% and 50.2% respectively, p < 0.005) as well as antiplatelet therapy rate (86.5%. 83.2% and 81.6% respectively p < 0.005) and statin therapy rate (78.2%. 51.9% and 57.8% respectively p < 0.005). CONCLUSIONS: Cardiovascular risk factor control in subjects at high risk of atherothrombosis or who have established VD is poor. It is poorer in primary prevention and in PAD patients. Whilst the use of statins is insufficient, the use of antithrombotic medication is acceptable in secondary prevention but considerably lacking in primary prevention.

On-line laser radiation controlled to the removal of adhesive on teeth after bracket debonding.

BACKGROUND AND AIMS: After bracket debonding a correct removal of the adhesive from tooth surfaces without causing any iatrogenic damage to the enamel is needed. However, conventional techniques do not allow a selective removal process. The present article focuses on the removal of adhesive on teeth after bracket debonding by using laser radiation at 355 nm (third harmonic wavelength of a Q-switched Nd:YAG). MATERIAL AND METHODS: Brackets were bonded to 10 extracted human premolars from young patients and removed after a storage period of 2 months. As real-time diagnostic technique, laser-induced breakdown spectroscopy (LIBS) elemental analysis was applied for precisely controlling the removal of the adhesive and morphological analysis of the etched surfaces was carried out by scanning electron microscopy (SEM). RESULTS: LIBS technique allowed an on-line precise control in the adhesive removal process. SEM analysis revealed the capability of the 355 nm UV laser radiation to complete the removal of the adhesive on the tooth with no signs of damage on the enamel. CONCLUSION: Laser ablation process at 355 nm monitored by the LIBS technique allows to carry out efficient removal of the adhesive on teeth.

Impact of delayed gratification on oral health and caries status in the primary dentition.

OBJECTIVE: The ability to delay gratification (ATDG) is naturally linked to key regulatory psychological traits involved in self-discipline/regulation. The aim of this study was to ascertain the normalized impact of ATDG as an early predictor of oral health, on the primary dentition. METHODS: 404 subjects [202 children (4-6 years old) and 202 mothers] were enrolled in a case-control study. Systematic data collection included: i) extraoral diagnostic parameters; ii) intraoral health status; iii) behavioral aspects; iv) baseline socio-demographic data. The ICC, the paired Student's t-test and kappa statistic were used to evaluate intra-observer reliability. Distributions were explored with the chi-squared test [Odds ratio;95%CI;p<0.05]. Conditional logistic regression was used to evaluate associations between all clinical diagnostic data and ATDG. RESULTS: Overweight/obese children and those diagnosed with ADHD are more prone to lack ATDG (p<0.001). Higher deft values were observed in children who lacked ATDG, who were also strongly associated with higher sugar consumption and more impulsive personalities (p<0.001;OR:.107/0.031;95%CI:036-0.316/0.008-0.115). By contrast, children with responsible personality traits were associated with this skill (p<0.028;OR:3.33;95%CI:1.1-9.7) and obtained the lowest deft (p<0.306;OR:0.539;95%CI:0.165-0.176) and gingival index values (p<0.001;OR:10.44;95%CI:2.6-40.9), which are clear indicators of better current and future oral health. CONCLUSIONS: These data provide insights into a novel predictor for identifying individuals at a higher risk of dental caries in early childhood. CLINICAL SIGNIFICANCE: The present study offers a new hypothesis for identifying individuals with poor oral health status. Early tools to detect the most vulnerable population sectors are critically important to reduce the global burden of caries and other oral diseases.

Short- and Medium-Term Effects of Low-Level Laser Therapy on Periodontal Status in Lingual Orthodontic Patients.

OBJECTIVE: The purpose of this study was to evaluate the short- and medium-term effects of low-level laser therapy (LLLT) applied in repeated doses in adults with a healthy periodontium treated by lingual orthodontic appliances. BACKGROUND DATA: Plaque accumulation, in combination with difficulty in removing it in lingual orthodontic patients, can cause gingival inflammation. METHODS: Twelve orthodontic patients scheduled for fixed lingual orthodontic treatment were selected. Clinical measurements [visible plaque index (VPI), bleeding on probing (BOP), and probing depth (PD), and collection of gingival crevicular fluid (GCF)], which was used to measure the levels of interleukin-1beta (IL-1ß) and tumor necrosis factor alpha (TNF-α), was performed before bonding the lingual device, and at the short-term (1, 2, 3 months) and medium-term (12 months) follow-up appointments. For each patient, quadrant 1 or 2 was randomly chosen for irradiation by a diode laser (λ = 670 nm, 190 mW, 6.05 W/cm(2), 60 sec/ tooth) (Laser Group) and the contralateral quadrant was used as the Control Group. RESULTS: In both studied groups, a slight worsening of the periodontal condition was observed, which was evident at the 3rd month follow-up and which was mainly at the lingual side in the Control Group. The levels of IL-1ß in the GCF were significantly increased in the Control Group compared with the Laser Group at the 2nd and 3rd months after bonding. At the 12th month follow-up, an improvement of the inflammation was observed in both groups in the study. CONCLUSIONS: LLLT showed short-term effects by preventing a substantial increase in IL-1ß levels. At medium-term follow-up, LLLT diminished VPI, BOP, and PD scores.

Long-term stability of rapid maxillary expansion combined with chincup protraction followed by fixed appliances.

OBJECTIVE: To analyze the long-term stability of rapid maxillary expansion (RME) and protraction from chincup therapy in girls with Class III malocclusion. MATERIALS AND METHODS: Twenty-two girls (mean age  =  9.1 ± 0.6 years) with Class III malocclusion were treated with combined RME and protraction from a chincup, followed by fixed appliances. Lateral cephalograms were evaluated before treatment, at the end of a two-phase treatment protocol (mean age  =  15.1 ± 1.1 years), and 10.9 ± 0.5 years after the end of treatment (mean age  =  27.5 ± 0.5 years). The control group consisted of 22 matched girls with skeletal Class I malocclusion. RESULTS: After treatment, the Class III group showed significant improvement of the Class III malocclusion, mainly due to changes in the mandible (ie, SNB angle decreased 1.8 ± 1.6°) and significant improvement of the sagittal maxillomandibular relationship (Wits appraisal increased 2.6 ± 2.1 mm; ANB angle increased 1.0 ± 0.3 mm). These changes remained stable for an average of 10 years after the end of therapy. No tendency toward relapse was detected, and the mandibular position showed favorable outcomes. CONCLUSIONS: RME and protraction from chincup therapy led to successful long-term outcomes in 18 of 22 patients (81.8%). This treatment approach can be considered an efficient therapy in growing girls with mild skeletal Class III malocclusion caused by maxillary retrusion and mandibular protrusion.

Longitudinal evaluation of sEMG of masticatory muscles and kinematics of mandible changes in children treated for unilateral cross-bite.

The aim of this study was to evaluate masticatory muscle activity and kinematics of mandible changes in children with unilateral posterior cross-bite (UPXB) after orthodontic treatment, and one year after retention. Twenty-five children with UPXB and functional mandibular shift were evaluated before treatment (mean age 12.5years), after treatment (mean age 14.9years), and one year after retention (mean age 16.8years). The same data were collected in a control group of thirty age-matched normocclusive children. Simultaneous bilateral surface electromyographic (sEMG) activity from anterior temporalis (AT), posterior temporalis (PT), masseter (MA), and supra-hyoid (SH) muscle areas were evaluated at rest, during swallowing, mastication and clenching. Kinematic records of rest position, mandibular lateral shift, swallowing and mastication were analyzed. Results showed a lateral shift of the mandible present at rest. During swallowing, sEMG activity of SH predominated before and post-treatment and retention. High frequency of immature swallowing was maintained post-treatment and retention. During mastication, MA activity increased significantly and its asymmetry was corrected post-treatment. During clenching, cross-bite side AT and MA activity increased significantly posttreatment and remained stable after retention, and MA/AT ratio reversed. These findings reinforce the advantages of treating children with UPXB and functional shift as early as possible.

Activity of jaw muscles in unilateral cross-bite without mandibular shift.

OBJECTIVES: To evaluate and compare electromyographic activity of jaw muscles at rest and during maximal voluntary clenching in maximal intercuspation between growing individuals with unilateral posterior cross-bite without functional mandibular lateral shift during closure and matched individuals with normal occlusion. These findings may help elucidate the impact of this occlusal condition on jaw muscle function and the therapeutic implications. DESIGN: 30 growing children (10-12 years) with unilateral cross-bite without functional mandibular lateral shift during closure (cases) and 30 age- and sex-matched children with normal occlusion (controls) were consecutively selected applying highly restrictive criteria. Electromyographic activity coming from the areas of right and left anterior temporalis, posterior temporalis, masseter, and supra-hyoid muscles was evaluated at rest and during clenching. The asymmetry index was calculated for each muscle area to quantify the degree of asymmetry between sides. The masseter/anterior temporalis ratio during clenching was also recorded. RESULTS: No significant differences were found between groups at rest. During clenching, activity of the cross-bite side masseter area was significantly lower in cases versus controls but no difference was found between cross-bite and non-cross-bite sides of this muscle. CONCLUSIONS: Unilateral posterior cross-bite without functional mandibular lateral shift is associated with a lower electromyographic activity of masseter muscle area of the cross-bite side during maximal clenching in maximal intercuspation, compared to the children with normal occlusion. This result could suggest a functional adaptation that should be carefully considered. Long-term studies are needed to determine future repercussions and to evaluate the benefit of an early treatment.

Skeletal maturation determined by cervical vertebrae development.

The aim of this study was to determine the validity of cervical vertebrae radiographic assessment to predict skeletal maturation. Left hand-wrist and lateral cephalometric radiographs of 958 Spanish children from 5 to 18 years of age were measured. On the left hand-wrist radiographs the classification of Grave and Brown was used to assess skeletal maturation. Cervical vertebrae maturation was evaluated with lateral cephalometric radiographs using the stages described by Lamparski and by Hassel and Farman. A new method to evaluate the cervical maturation by studying the changes in the concavity of the lower border, height, and shape of the vertebral body was created. Correlation coefficients were calculated to establish the relationship between skeletal maturation values obtained by the three classifications of vertebral and skeletal maturation measured at the wrist. All correlation values obtained were statistically significant (P < 0.001). The results suggest that this new method to determine skeletal maturation is very reliable. A simple method based on morphological characteristics of the cervical vertebral bodies to evaluate the maturation stage has been designed. In the population investigated, this method is as accurate as the Hassel and Farman classification and superior to the Lamparski classification. The morphological vertebral parameter best able to estimate the maturation is the concavity of the lower border of the body.