Evaluation of effectiveness of photobiostimulation in alleviating side effects after dental implant surgery. A randomized clinical trial.

BACKGROUND: To assess if photobiostimulation (PBS) alleviates pain intensity/duration and swelling after implant surgery. MATERIAL AND METHODS: Sixty subjects (27 male and 33 female, with a mean age of 47,13 8.05 years) were included and randomly assigned to experimental group (implant surgery and photobiostimulation), placebo group (implant surgery and simulated photobiostimulation) and control group (implant surgery only). INCLUSION CRITERIA: subjects older than 20 years, with a healthy oral mucosa and requiring implant surgery. EXCLUSION CRITERIA: pregnancy, history of implant failure, light sensitivity, metabolic deseases, consumption of antibiotics or corticosteroids in the last two weeks, smokers and alcohol drinkers. Patients reported the pain experienced by using a numeric rating scale (NRS) at 2 hours, 6 hours, 12 hours, 24 hours and from day 2 to 7. Swelling score was assessed by linear measurements and type and number of analgesic drugs within each time-point were recorded on a spreadsheet. Data of pain and amount of swelling were compared among the three groups by using the Kruskal-Wallis H Test and post-hoc comparisons tests. RESULTS: Pain in the experimental group was less compared to controls and placebo group, at each time intervals (p < 0.001) as well as the maximum pain score (experimental group: median = 2, interquartile range 2-3; control group: median = 8, interquartile range 3,75-9; placebo group: median = 8, interquartile range 6,25-9). Swelling was almost insignificant in the experimental group (maximum value = 1, interquartile range 0-2,75, at 24 hours) compared with control (maximum value = 6, interquartile range 5-8,75, at 24 hours) and placebo (maximum value = 6, interquartile range 5-8, at 24 hours). Subjects in the experimental group assumed less analgesics compared to both controls and placebo groups. CONCLUSIONS: Photobiostimulation is an effective method to reduce pain intensity/duration and swelling after implant surgery.

Influence of occlusal characteristics, food intake and oral hygiene habits on dental caries in adolescents: a cross-sectional study.

AIM: Dental caries is one of the most common oral diseases affecting children. The complex multifactorial aetiology of caries involves host (saliva composition and tooth enamel characteristics), oral microflora and substrate (oral hygiene quality and dietary habits composition). Occlusal characteristics may be also a factor in dental caries development. The aim of this aepidemiologic study was to verify the association between DMFT (Decayed, Missed, Filled Teeth) index and occlusal characteristics, dietary habits, oral hygiene habits and parents' education level in a sample of 12-year-old schoolchildren from Southern Italy. MATERIALS AND METHODS: A sample of 536 children was examined to detect dental caries status and several occlusal variables (i.e. molar relationship, overjet and overbite, presence of crossbite, scissor bite, crowding, diastemas and/or midline deviation). A questionnaire to retrieve parents' educational level, patient's dietary and oral hygiene habits was administered. The associations among these variables were assessed statistically through the ?2 test. RESULTS: A positive association was found between caries, parents' social status and some occlusal disorders. va specificato, l'abstract non può essere una caccia al tesoro. In relation to occlusal variables, crossbite (?2=3.96, P=0.04) was significantly associated to caries. A significant association was also found between the education level of mothers (?2=7.74, P<0.01) and fathers (?2=6.35, P=0.01) and the presence of caries. Dietary habits, oral hygiene and remaining occlusal characteristics were not associated with caries presence (all P>0.05). CONCLUSIONS: Of the evaluated occlusal characteristics only posterior crossbite was associated with caries prevalence. Education level of the parents was the other factor significantly associated with caries. Dietary habits, oral hygiene frequency and the remaining occlusal characteristics were not associated with dental caries.

Dentoskeletal features in mixed dentition children with displaced maxillary canines in a southern Italian population.

AIM: To analyse the prevalence and the distribution of displaced, buccal/palatal maxillary canines, and the association with sagittal and vertical skeletal relationships in a southern Italian population. MATERIALS AND METHODS: Consecutive records of patients were examined. Inclusion criteria were: age 7-12 years, 1-2 cervical vertebral maturation (CVM) stage, initial dental casts, intraoral photographs, panoramic, lateral and periapical radiographs. Subjects with at least one canine in Lindauer II, III or IV sector and/or α angle >31° were included in displaced maxillary canine (DMC) group, whereas those with both canines in sector I and α angle ≤31° were used as control group (CTR). According to canine bulges and/or x-ray examinations, DMC were then divided in palatal and buccal displaced canines (PDC/BDC). Sagittal and vertical skeletal relationships were evaluated using ANB and SN/GoMe angles. Chi-square tests were performed to compare the prevalence rates of skeletal features. RESULTS: The sample consisted of 123 children, 40 DMC and 83 CTR. The DMC group included 11 PDC and 29 BDC subjects. The M:F ratio was 1:3 in PDC and BDC, 1:1 in CTR group. The unilateral-to-bilateral ratio was 1:1 and 3:1 in PDC and BDC subjects. The most common sector combination regarding unilateral and bilateral displacements was "II" and "II,II". PDC occurred more in Class I and in hyperdivergents, whereas BDC in Class I or II and in normodivergents. CONCLUSIONS: DMC occurred more often in females than in males. BDC was more common than PDC and unilateral displacements occurred more frequently than bilateral ones. No significant correlation with skeletal features was observed.

Pharyngeal airway changes in pre-pubertal children with Class II malocclusion after Fränkel-2 treatment.

AIM: To evaluate two-dimensional changes in pharyngeal airway dimensions in pre-pubertal children with a Class II malocclusion treated with a Fränkel-2 appliance compared to a matched non-treated control sample. MATERIALS AND METHODS: Lateral cephalograms obtained from 28 consecutively treated pre-pubertal children before (T0) and after (T1) a one-year Fränkel-2 treatment were analysed. Fränkel-2 appliance was used for at least 18 hr/day during 12 months. The control group was matched as closely as possible. All the cases presented normal facial growth pattern. Sagittal and vertical cephalometric measurements assessing maxillary and mandibular skeletal positions, as well as sagittal pharyngeal airway dimensions, were calculated. Intraclass correlation coefficient was calculated in order to determine reliability. Differences based on age for all the outcome variables at T0 were compared with an independent t-test. A MANOVA was used thereafter to determine if any factors and their interactions were associated with changes in the outcome variables. Differences between T1 and T0 were evaluated with either a t-student test or a Mann Whitney U test. RESULTS: At T0 differences between groups were noted for several variables. These differences were considered during the follow-up statistical analysis. Changes between groups after treatment (T1-T0) were noted for SNB, PNS to Ba, McNamara Low and Middle to S (increase in treatment group), and ANB and AD1 to Ba (decrease in treatment group). CONCLUSIONS: Some pharyngeal two-dimensional airway dimensions changed in Class II malocclusion pre-pubertal patients during a one-year treatment with Fränkel-2 appliances.

Dentin caries progression and the role of metalloproteinases: an update.

AIM: This review aims to summarise our understanding of the destructive role of acid environment and metalloproteinases in dentin caries progression using a review process. METHOD: The acids resulting from consumption of sugars by acidogenic and aciduric bacteria can cause demineralisation of the tooth surface, but are not able to cause caries-like lesions. The appearance of such lesions requires the activation of enzymatic proteolysis in an acidic environment for degradation of the dentin organic matrix, leading to cavity formation. Bacterial collagenases have long been considered responsible for organic matrix destruction; host cell-derived matrix metalloproteinases (MMPs) have recently been considered to be involved in the dentinal matrix destruction of carious lesions. DISCUSSION AND CONCLUSION: MMPs are initially synthesised as inactive zymogens to be activated in acid environment of dentinal fluid during the carious process, resulting in destruction of the collagenous matrix. The role of acid environment on enamel and dentin demineralisation and the role of salivary and dentinal MMPs in dentin progression of caries has encouraged general dentists to include the monitoring of oral environment not only by control of bacterial oral flora in caries treatment protocol, but mainly by inhibition of dentinal and salivary MMPs through the use of toothpaste and/or mouthwash containing specific active agents.

Prevalence of dental anomalies in children with cleft lip and unilateral and bilateral cleft lip and palate.

AIM: To examine the prevalence of different types of dental anomalies in children with nonsyndromic cleft lip, unilateral cleft lip-palate, and bilateral cleft lip-palate. MATERIALS AND METHODS: A sample of 90 patients (aged 4-20 years) affected by isolated cleft lip, unilateral and bilateral cleft lip and palate was examined. Cleft patients were classified into one of three groups according to cleft type: (1) Unilateral Cleft Lip-Palate, (2) Bilateral Cleft Lip-Palate, and (3) Cleft Lip. Intraoral exams, panoramic radiographs and dental casts, were used to analyse the prevalence of the various dental anomalies included in this study. RESULTS: There were no statistically significant differences between patients with cleft lip, unilateral cleft lip and palate and bilateral cleft lip and palate. The congenital absence of the cleft-side lateral incisor was observed in 40% of the sample, and a total of 30% patients showed supernumerary teeth at the incisors region. Second premolar agenesis was found in 4.4% of patients, whereas in 18.9% of the sample there was an ectopic dental eruption. Lateral or central incisors rotation was noted in 31.1% of the sample, while shape anomaly, lateral incisor microdontia, and enamel hypoplasia were detected respectively in 25.6%, 5.6% and 18.9% of cleft patients. CONCLUSION: High prevalence of different dental anomalies in children with cleft lip and unilateral and bilateral cleft lip and palate has been confirmed. This study, in particular, shows the presence of ectopic and rotated teeth in the cleft area.

Maturation of the middle phalanx of the third finger and cervical vertebrae: a comparative and diagnostic agreement study.

OBJECTIVE: Diagnostic agreement on individual basis between the third middle phalanx maturation (MPM) method and the cervical vertebral maturation (CVM) method has conjecturally been based mainly on overall correlation analyses. Herein, the true agreement between methods according to stage and sex has been evaluated through a comprehensive diagnostic performance analysis. SUBJECTS AND METHODS: Four hundred and fifty-one Caucasian subjects were included in the study, 231 females and 220 males (mean age, 12.2 ± 2.5 years; range, 7.0-17.9 years). The X-rays of the middle phalanx of the third finger and the lateral cephalograms were examined for staging by blinded operators, blinded for MPM stages and subjects' age. The MPM and CVM methods based on six stages, two pre-pubertal (1 and 2), two pubertal (3 and 4), and two post-pubertal (5 and 6), were considered. Specifically, for each MPM stage, the diagnostic performance in the identification of the corresponding CVM stage was described by Bayesian statistics. RESULTS: For both sexes, overall agreement was 77.6%. Most of the disagreement was due to 1 stage apart. Slight disagreement was seen for the stages 5 and 6, where the third middle phalanx shows an earlier maturation. CONCLUSIONS: The two maturational methods show an overall satisfactorily diagnostic agreement. However, at post-pubertal stages, the middle phalanx of the third finger appears to mature earlier than the cervical vertebrae. Post-pubertal growth phase should thus be based on the presence of stage 6 in MPM.

Speech outcome in unilateral complete cleft lip and palate patients: a descriptive study.

AIM: In this study, resonance and articulation disorders were examined in a group of patients surgically treated for cleft lip and palate, considering family social background, and children's ability of self monitoring their speech output while speaking. MATERIALS AND METHODS: Fifty children (32 males and 18 females) mean age 6.5 ± 1.6 years, affected by non-syndromic complete unilateral cleft of the lip and palate underwent the same surgical protocol. The speech level was evaluated using the Accordi's speech assessment protocol that focuses on intelligibility, nasality, nasal air escape, pharyngeal friction, and glottal stop. Pearson product-moment correlation analysis was used to detect significant associations between analysed parameters. RESULTS: A total of 16% (8 children) of the sample had severe to moderate degree of nasality and nasal air escape, presence of pharyngeal friction and glottal stop, which obviously compromise speech intelligibility. Ten children (10%) showed a barely acceptable phonological outcome: nasality and nasal air escape were mild to moderate, but the intelligibility remained poor. Thirty-two children (64%) had normal speech. Statistical analysis revealed a significant correlation between the severity of nasal resonance and nasal air escape (p ≤ 0.05). No statistical significant correlation was found between the final intelligibility and the patient social background, neither between the final intelligibility nor the age of the patients. CONCLUSION: The differences in speech outcome could be explained with a specific, subjective, and inborn ability, different for each child, in self-monitoring their speech output.

Upper and lower arch changes after Mixed Palatal Expansion protocol.

AIM: The aim of this study was to evaluate upper and lower dental changes after Mixed Palatal Expansion (MPE) treatment in growing patients with posterior single or bilateral crossbite and mild-to-moderate crowding, as compared to untreated growing subjects by dental cast analysis. MATERIALS AND METHODS: A group of 24 patients (18 girls, 6 boys) was treated with Hyrax-type device and compared with an untreated matched control group at T0 (8.6 yrs. ± 2) and at T1 (10 yrs. ± 2) using dental casts. The dental cast 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: The MPE group showed significant upper and lower arch changes when compared with the control group. Upper intermolar, interpremolar-2nd, interpremolar-1st (P<0.001) and intercanine widths (P<0.05) showed considerable changes in the treated group, while mandibular intermolar (P<0.001), interpremolar-1st (P<0.05) and intercanine widths (P<0.01) were slightly greater in the MPE group when compared with the control group. CONCLUSION: The changes in transverse upper and lower arch dimensions were significant, when compared with those seen in the control group.

Dento-skeletal effects of mixed palatal expansion evaluated by postero-anterior cephalometric analysis.

AIM: The aim of this study was to evaluate the dento-skeletal effects of mixed palatal expansion (MPE) on growing patients with a uni- or bilateral posterior crossbite and mild-to-moderate crowding as compared to untreated growing individuals using postero- anterior (PA) cephalometric analysis. MATERIALS AND METHODS: A group of 24 patients (18 girls and 6 boys) treated with a Hyrax- type device was compared to an untreated matched control group at T0 (8.6 yrs ± 2.01) and T1 (10 yrs ± 2.00) using PA cephalograms. The cephalometric analysis included eight bilateral skeletal and dental landmarks. The groups were compared using independent sample t-test to estimate dento-skeletal effects on PA cephalograms. RESULTS: The treated group showed significant changes for the maxillary width (P<0.001) and upper molar width (P<0.001) when compared to those of the control group. CONCLUSION: MPE may effectively increase transverse dimensions and correct posterior crossbites.

Assessment of host defence mechanisms induced by Candida species.

Some species of Candida are opportunistic pathogens that can cause disease in a host immunocompromised by underlying local or systemic pathological processes. C. albicans is the species most often associated with oral lesions, but other species of Candida, including C. glabrata, C. tropicalis and C. parapsilosis, have also been isolated in the saliva of subjects with and without candidiasis. In the present study we evaluated the host defence mechanisms induced by Candida albicans and other Candida species in monocytes and oral epithelial cells in order to establish the existence of a species-specific cellular response. Our results indicated that, during Candida species infection, the epithelial cells actively participate in the host defence by producing antimicrobial peptides and proinflammatory cytokines. Moreover, in infections caused by Candida tropicalis and Candida glabrata, the host defence may be strengthened by the release of perforin and granzyme by polymorphonuclear leukocytes recruited at the site of infection.

[Craniofacial morphology and obstructive sleep apnoea-hypopnoea syndrome: a craniometric comparative analysis]. / Morfologia craniofacciale e sindrome delle apnee-ipopnee ostruttive nel sonno: un'analisi craniometrica comparativa.

PURPOSE: The aim of this study was to define the relationship between paediatric obstructive sleep apnoea-hypopnea syndrome (OSAHS) and craniofacial morphovolumetric features through comparative craniometric analyses between affected children and controls based on conventional cephalometry. MATERIALS AND METHODS: Cephalometric examinations of 40 children affected by OSAHS were retrospectively evaluated. Sixteen craniometric landmarks were identified, and 27 linear and angular indices related to craniofacial morphovolumetric features were measured. Subsequently, the same process of identifying landmarks and measuring indices was performed on the cephalometric examinations of 40 controls. For each index, we then calculated in both groups the mean, standard deviation, standard error and p value. By comparing the values obtained in the two series, we calculated the degree of significance of each difference between children with OSAHS and controls using the Student t test. RESULTS: Differences of only 5/27 linear and angular indices considered were not statistically significant between groups, thus confirming susceptibility to the disorder in relation to certain splanchnocranic morphovolumetric features. The most significant differences involved mandibular plane inclination and distance between landmark sella and hyoid bone, a reliable index being the vertical position of the latter. CONCLUSIONS: Despite the limitations associated with the 2D nature of conventional cephalometry, mainly related to projection and identification errors, and despite the upright position during examination, we consider the diagnostic value and information content of this technique high, thus reaffirming its role as a first-line imaging investigation in children with sleep-related breathing disorders.

A computed tomography-based comparative cephalometric analysis of the Italian craniofacial pattern through 2,700 years.

The aim of our study was to define the changes in morphovolumetric features of neurocranium, basicranium and splanchnocranium in the population of Campania, southern Italy, over the last 2,700 years. This was a very intense period for this region from both historical and evolutionary perspectives and was marked by the succession of colonisations, dominations and invasions by several European and non-European peoples, events that profoundly influenced the original genetic heritage, which subsequently became more complex. Unlike most previous authors, we based our craniometric comparative analysis on multidetector computed tomography (MDCT) studies of contemporary and ancient series dating to between the seventh and fifth centuries B.C. of skulls found in the Etruscan necropolis of Pompei and Pontecagnano. MDCT is extremely reliable in identifying landmarks and measuring linear and angular indices through the use of multiplanar and tridimensional reformations. While highlighting a remarkable stability of 22/32 of the indices considered, as an effect of the role of the genetic heritage in preserving morphovolumetric features in a given population, statistical analysis showed some interesting results: the main changes concerned the splanchnocranium and the occlusion, indicating a higher sensitivity of these districts to environmental factors, mainly related to diet. Conversely, neurobasicranial complex morphovolumetric features remained amazingly intact. In particular, the neurocranium increased in overall capacity in response to the growing brain and changed shape with a progressive shift to a dolichocranic, flattened frontal pattern; the basicranium shape was preserved, as indicated by the stability of the cranial base (NSBa) angle over time. The splanchnocranium, on the contrary, has undergone a dramatic involution, even conditioning gnathic structures with changes in palatal shape (more acute) and in the relationship between the jaws on the sagittal plane, resulting in increased prevalence of Angle's class I and III malocclusions.

Differences in craniofacial characteristics in Southern Italian children from Naples: a retrospective study by cephalometric analysis.

AIM: The present cross-sectional survey was performed to determine cephalometric standards in a large sample (n. 1071) of children from Southern Italy (Naples). MATERIALS AND METHODS: 1071 lateral cephalograms of healthy children, between 8 to 12 years, with various types of occlusion, all with no history of orthodontic treatment before cephalometric analysis were examined. Seven angular and three linear length measurements (SNA, SNB, ANB, SN^GoMe, PN^Pal I^SN, i^GoMe), and three ratios were included. Descriptive statistics, including the mean, standard deviation, and maximum and minimum, values was computed for each cephalometric variable. RESULTS: Changes in angular and linear parameters during the observation period occurred mostly between the ages of 10 and 12 years. The three ratios varied from age and were not characterised by a progressive rise in mean values. Se-N/Go-Pg was greater in 11-year-old boys (p <0.05) and 12-year-old boys (p <0.01); the cranio-maxillary index Se-N/PNS-A1 was greater in 9-year-old girls (p <0.05), whereas the maxilla-mandibular index PNS-A1/Go-Pg was greater in 9-year-old boys (p <0.01). CONCLUSION: The findings provided useful reference cephalometric normative measures for the 8-to-12-year-old Southern Italian children population. Significant differences between boys and girls in the length of the anterior cranial base and ratio were reported.

Treatment effects of R-appliance and Fränkel-2 in Class II division 1 malocclusions.

AIM: The purpose of this study was to compare the effects of a differently designed functional appliance (the R- appliance) with Fränkel-2. STUDY DESIGN: Twenty-seven patients (16 girls and 11 boys) with a mean age of 9.8 (SD 1.6) years were treated with the R-appliance for 15.4 (SD 0.4) months and twentyseven (15 girls and 12 boys) patients with a mean age of 9.1 (SD 1.1) years were treated with a Fränkel-2 appliance for 19 (SD 5.6) months. All patients had Class II division 1 malocclusions due to mandibular deficiency and all of them had prepubertal stages of skeletal development. Lateral cephalograms obtained at the beginning (T1) and at the end (T2) of the study were analysed. RESULTS: Paired t-tests showed that SNB significantly increased in both groups. The incisor mandibular plane angle (IMPA) was reduced in the R- appliance group by 2.2 (SD 4.9) degrees (P<0.03) but increased by 2.2 (SD 2.6) degrees (P<0.001) in the Fränkel-2 group. The SNA in the R-appliance group showed an increase of 0.2 (SD 2) degrees (P<0.6), while it was decreased by 0.4 (SD 0.5) degrees (P<0.6) in the Fränkel-2 group. CONCLUSIONS: Both treatment modalities were successful in moving the mandible forward. However, with the R-appliance, this was achieved without proclination of the lower incisors.

Cytokines and VEGF induction in orthodontic movement in animal models.

Orthodontics is a branch of dentistry that aims at the resolution of dental malocclusions. The specialist carries out the treatment using intraoral or extraoral orthodontic appliances that require forces of a given load level to obtain a tooth movement in a certain direction in dental arches. Orthodontic tooth movement is dependent on efficient remodeling of periodontal ligament and alveolar bone, correlated with several biological and mechanical responses of the tissues surrounding the teeth. A periodontal ligament placed under pressure will result in bone resorption whereas a periodontal ligament under tension results in bone formation. In the primary stage of the application of orthodontic forces, an acute inflammation occurs in periodontium. Several proinflammatory cytokines are produced by immune-competent cells migrating by means of dilated capillaries. In this paper we summarize, also through the utilization of animal models, the role of some of these molecules, namely, interleukin-1ß and vascular endothelial growth factor, that are some proliferation markers of osteoclasts and osteoblasts, and the macrophage colony stimulating factor.

Adverse reaction to irrigation with povidone-iodine after deep-impacted, lower third molar extraction.

Povidone-iodine is most commonly used worldwide because of its germicidal activity, relatively low irritancy or toxicity and low cost. Frequently, povidone-iodine is used as a topical antiseptic for treating and preventing wound infection. In rare cases skin irritation or iododerma-like eruption could represent possible adverse effects due to the oxidative effects of iodine and allergic hypersensitivity reaction. In this report we describe a case of a massive adverse reaction to the irrigation of surgical wound dehiscence with 10 percent povidone-iodine solution after deep-impacted, lower third molar extraction. This reaction was related to a central neurotrophic reflex involving three trigeminal branches and probably due to peripheral chemical insult of mandible nerve. This adverse reaction determined a severe edema and diffuse skin lesions, involving the whole left side of the face mimicking an iododerma-like eruption. These violent symptoms were solved after 60 days. Furthermore, we report a small permanent skin scar in the zygomatic area and transient alterations of facial sensitivity on the affected side which completely disappeared in 6 months.

Orthopaedic treatment efficiency in skeletal Class III malocclusions in young patients: RME-face mask versus TSME.

AIM: To cephalometrically compare the skeletal vertical and sagittal effects of TSME with those of RME protraction facemask therapy in Class III patients. MATERIALS AND METHODS: The sample of this retrospective study included 104 patients (53 females, 51 males) with age ranging from 5 to 9 years, presenting a skeletal Class III relationship: 52 were treated with transverse sagittal maxillary expander (TSME) appliance (Group 1) and 52 with Hyrax rapid maxillary expander/facemask (RME/FM, Group 2). For each patient a lateral cephalogram was obtained before treatment (T0) and at the end of the retention period (T1). Changes in the two groups during the observation period were calculated, compared and statistically analysed with t-test. RESULTS: TSME can produce skeletal changes and dento-alveolar modifications. RME in association with protraction facemask showed that after treatment the maxilla was moved significantly forward. The correction of the ANB angle was due to a change in mandibular position during treatment which showed a backward and downward rotation. CONCLUSION: Both devices were effective in the treatment of subjects with skeletal Class III due to maxillary retrusion.

Unilateral posterior crossbite in adolescents: surface electromyographic evaluation.

AIM: Unilateral posterior crossbite (UPCB) is characterised by an inverse relationship of the upper and lower buccal dental cusps and may involve one or several teeth. The aim of this study was to compare the electromyographic outcomes of patients with UPCB and those of healthy controls. MATERIALS AND METHODS: Fifteen patients (mean age 11.5 years) with UPCB and fifteen healthy controls (mean age 12 years) were examined at the Department of Orthodontics, Second University of Naples. Surface electromyography was performed on patients and controls. RESULTS AND CONCLUSION: Patients with UPCB had less muscle activation than healthy subjects (p<0.0001) and an asymmetric muscle activation with 89.23% muscle balancing for temporals and 83.21% for masseters. The control group showed a 99.32% of muscle balancing for temporals and 97.77% for masseters. These findings suggest that asymmetric muscle activation may influence maxillary and mandibular growth in adolescents with UPCB.

Class II malocclusion division 1: a new classification method by cephalometric analysis.

AIM: The purpose of this study was to analyse the craniofacial and dentofacial skeletal characteristics in untreated subjects with Class II, division 1 malocclusion by mandibular retrusion and to identify different types and their prevalence. MATERIALS AND METHODS: In 152 subjects with Class II, division 1 malocclusion by mandibular retrusion, the differences were determined by lateral cephalograms analysis of variance and chi-square test, respectively. P<0.05 was considered significant. Seven types of mandibular retrusion were identified: three pure, dimensional, rotational and positional, and four mixed. RESULTS: All patients showed significant inter-group differences with P between 0.005 and 0.001. The dimensional type was the most common (28.9%) and the rotational-positional type was the rarest (5.9%). The pure dimensional type had the shortest mandibular body; the pure rotational type had larger SN/GoMe and the lowest AOBO; the pure positional type presented the flattest cranial base, high AOBO. In the mixed types, dento-skeletal features changed depending on how the main types assorted. CONCLUSIONS: Identifying the type of mandibular retrusion is important for differential diagnosis in clinical practice and research.