Functional treatment of bilateral posterior crossbite improves mandibular kinematics during chewing.

OBJECTIVES: To evaluate the effects of treatment of bilateral posterior crossbite (BPXB) on mandibular kinematics by the percentage of reverse chewing cycles (RCCs) during soft and hard bolus chewing before and after the correction of the malocclusion with function-generating bite (FGB). MATERIALS AND METHODS: This prospective study included 71 subjects: 19 patients with occlusally symmetric BPXB (M = 9; F = 10; mean age 9.3 ± 2.2[yr.mo]), 32 patients with occlusally asymmetric BPXB (19 with more teeth in crossbite on the right side (right prevalent side), M = 7; F = 12; mean age 8.2 ± 1.6 [yr.mo] and 13 on the left side, M = 7; F = 6; mean age 9.6 ± 1.9 [yr.mo]) and 20 controls without malocclusion (M = 8; F = 12; mean age 10.2 ± 1.7 [yr.mo]). Masticatory patterns were recorded before (T0) and after (T1) the correction of the malocclusion with FGB, with the K7-I® kinesiograph using standardized soft and hard boluses. RESULTS: BPXB was corrected in all included patients. At T0, the percentage of RCCs in BPXB was significantly increased compared to controls (P < .0001); symmetric BPXB showed no difference in RCCs between the sides, whereas asymmetric BPXB showed significantly more RCCs on the side with more teeth in crossbite (prevalent side). After treatment with FGB (T1), the percentage of RCCs was significantly reduced in both symmetric BPXB patients (soft bolus, P = .003; hard bolus, P < .001) and asymmetric BPXB patients (prevalent side: soft and hard bolus, P < .00001; non-prevalent side: soft bolus, P = .01 and hard bolus, P = .0002). CONCLUSION: Functional correction of BPXB with FGB significantly improved mandibular kinematics during chewing.

Temporomandibular joint involvement in patients with Juvenile Idiopathic Arthritis: comparison of ultrasonography and magnetic resonance imaging in assessing the periarticular space width.

OBJECTIVES: This study aimed to compare the performance of Ultrasonography (US) and Magnetic Resonance Imaging (MRI) in assessing the Lateral Periarticular Space (LPAS) of Temporomandibular Joints (TMJs) in patients with Juvenile Idiopathic Arthritis (JIA). METHODS: The LPAS width was evaluated in two different patient groups. In the JIA group, including 29 children (13 ± 2.8 years) with JIA, the LPAS width was measured with both MRI and US. In the healthy group, including 28 healthy children (12.6 ± 2.5 years), the LPAS width was measured only with US. Comparisons of LPAS width based on patient groups and TMJ contrast enhancement in MRI were evaluated by applying the Mann-Whitney U test. Correlation and agreement between MRI and US measurements in JIA group were tested using Spearman rank correlation and Bland-Altman method. RESULTS: The LPAS width was significantly greater in the JIA group than in the healthy group. In the JIA group, the LPAS width was significantly greater in TMJs with moderate/severe enhancement than those with mild enhancement. A positive significant correlation between MRI and US measurements of LPAS width was found in the JIA group. In the same group, Bland-Altman method showed a good level of agreement between MRI and US measurements. CONCLUSION: Although, US cannot replace MRI in the evaluation of TMJ in patients with JIA, US could be used as a supplementary imaging method to MRI in assessing the TMJ disease.

Cranial structure and condylar asymmetry of adult patients with rheumatoid arthritis.

OBJECTIVE: The aim of this prospective cross sectional study was to evaluate the cranial structure and condylar asymmetry of adult patients with rheumatoid arthritis (RA) diagnosed after 25 years of age compared to a healthy adult control group. METHODS: Eighteen adult patients (57.4 ± 11.4 years) with RA were compared with a control group. Cephalometric analysis and the Habets method for the calculation of the condylar asymmetry were used. The main cephalometric data investigated were focused on the diagnosis of hyperdivergent cranial structure (NSL/ML, NL/ML), backwards rotation of the mandible (Fh/ML), short vertical ramus (Ar:Go), steep mandibular plane (ML/Oc). RESULTS: The cephalometric data considered were not significantly different in the RA vs controls except for the steepness of the occlusal plane (NL/Oc), which was steeper in the patients group (P < 0.02) and the ramus of the mandible which was greater in patients. The asymmetry of the condyles was significant (P < 0.003) and different from the control group, but that of the ramus was not. CONCLUSIONS: In this study, RA patients diagnosed after 25 years of age did not show a different pattern of growth with respect to the control group. As expected, the condyles showed a difference being asymmetrical in RA patients due to the high turnover of this joint reacting to severe systemic inflammation in conditions of continuous functional work, load and forces. This study follows a previous study with the same research plan conducted on young JIA patients who showed a different pattern of growth of the skull leading to a severe hyperdivergent cranial structure with backward rotation of the mandible; this is mainly due to the insufficient growth of the condylar site exposed to the inflammatory process during development. Unlike JIA patients, this study showed that RA patients follow an individual growth pattern not affected by inflammation, even if they show joint asymmetry.

"Association between posterior unilateral functional crossbite and asymmetrical spinal flexion: A prospective study".

Background: Unilateral posterior crossbite (UPC) with functional shift is a malocclusion that may have the potential to affect the masticatory function and the flexibility of the spine due to intrinsic occlusal, structural and functional asymmetries sustained by marked asymmetrical muscular activation. Research question: To investigate whether the presence of UPC with functional shift is associated with reverse chewing pattern and altered spine flexion. Methods: Patients with UPC and a control group of patients with normal occlusion were recorded when chewing soft and hard boluses using a Kinesiograph (Myotronics-Noromed Inc., USA) and spine alignment was assessed with an electronic inclinometer Spinal Mouse® system (Idiag AG, Switzerland). Results: There were 87 children with UPC in the patients' group among whom 38, with median (IQR) age 8.0 (7.3-9.3) years, had measurements before and after treatment. The UPC patients showed a higher percentage of anomalous/reverse chewing patterns on the crossbite side compared with a control group (p < 0.001). Moreover, a clear difference was observed between left and right flexion angles of the spine in the patients' group (p < 0.001 and p = 0.001, paired t-test) with the crossbite side being more flexible compared to the non-crossbite side. No such differences were seen in the control group, nor post-treatment for right and left crossbite (p = 0.44 and p = 0.15 respectively, paired t-test). Significance: This study suggests an association between UPC, asymmetrical chewing patterns and asymmetrical flexion of the spine. These results may help improve understanding of any association between dental malocclusions and spine posture and hence aid diagnosis and treatment strategies.

Arthrogryposis multiplex congenita with maxillofacial involvement: a case report.

BACKGROUND: Arthrogryposis multiplex congenita is a rare condition that mainly involves the lower limbs, characterized by severe joint deformity and contracture, muscular atrophy, and functional impairment. Its clinical manifestations are heterogenous and may involve the maxillofacial district as well. CASE PRESENTATION: This case report describes a 20-year-old patient with arthrogryposis multiplex congenita with skeletal crossbite, facial asymmetry, reduced mouth opening and absence of lateral mandibular movement on the left side. After clinical evaluation, the following exams were required: postero-anterior cephalometric tracing, head and neck electromyography, computerized axiography, computed tomography scan, and maxillofacial magnetic resonance imaging. Orthognathodontic evaluation indicated skeletal asymmetry, reduced condylar movements on the left side and abnormally low electromyography activity of the masticatory muscles on the left side. Computed tomography and magnetic resonance imaging revealed unilateral left mandibular hypoplasia, hypotrophy, and fatty infiltration of masticatory muscles on the left side, as well as immobility of the left condyle during mouth opening, and hypoplasia of the left articular disk, which was however not displaced. Surgery was not indicated and conservative orthognathodontic treatment with function generating bite was suggested to balance the occlusal plane, as well as stretching exercises. CONCLUSIONS: A rare case of arthrogryposis multiplex congenita with maxillofacial involvement illustrates that a patient-centred, multidisciplinary approach with accurate diagnosis is required to formulate the best treatment plan. Because of the considerable damage to the masticatory muscles, conservative orthognathodontic therapy may be the best treatment option.

Improvement in the transverse dimension of dental arches in mixed dentition patients with posterior crossbite treated with functional therapy.

OBJECTIVES: To evaluate the effects of treatment of posterior crossbite (PXB) in the mixed dentition with the Function Generating Bite (FGB) appliance on the transverse dimension of the dental arches. MATERIALS AND METHODS: This study included 84 PXB patients (female = 46; male = 38; mean age, 8.2 ± 1.8 years) and 69 control (C) patients (female = 31; male = 38; mean age, 8.9 ± 1.4 years). Measurements were taken with digital calipers on maxillary and mandibular study casts before (T0) and after (T1) treatment for the following measures: intermolar (IMD), intermolar gingival (IMGD), intercanine (ICD), and intercanine gingival distances (ICGD). RESULTS: At T0, there was a significant difference in all maxillary measurements between the PXB and C groups (P < .001), reflecting maxillary hypoplasia in PXB patients. At T1, there was no difference between the groups. In PXB patients, the mean increase between T0 and T1 for IMD was 4.34 ± 2.42 mm; this difference measured 3.51 ± 2.19 mm for IMGD, 2.78 ± 2.37 mm for ICS, and 1.89 ± 1.7 mm for ICGD. There was no significant difference in mandibular measurements between groups at T0 and T1. CONCLUSIONS: Functional therapy with FGB is effective in significantly increasing the transverse dimension of the maxillary dental arch in PXB patients. Considering its efficacy in treating masticatory dysfunction, FGB may be considered a good treatment option for the correction of PXB in growing children.

Spinal disorders and mastication: The potential relationship between adolescent idiopathic scoliosis and alterations of the chewing patterns.

OBJECTIVE: To evaluate mastication in a group of patients with adolescent idiopathic scoliosis (AIS) with a control group, by means of the prevalence of reverse chewing cycles (RCCs). MATERIAL AND METHODS: This study included a group of patients (N = 32; F = 24; M = 8; mean age ± SD = 14 ± 3 years) with a confirmed diagnosis of AIS and a group of control subjects (N = 32; F = 24; M = 8; mean age ± SD = 13 ± 6 years) without spinal disorders. Mastication was recorded with both a hard and a soft bolus, following a standardized protocol, and the prevalence of RCCs was compared between the groups. RESULTS: The prevalence of RCCs was significantly higher in the AIS group, with both a soft and a hard bolus, compared to the control group (P < .001). CONCLUSION: The results of this study indicate that the presence of AIS influences mastication, one of the main functions of the stomatognathic system. A multidisciplinary approach to these patients may be relevant in providing the best possible treatment outcomes.

Condylar Asymmetry in Children with Unilateral Posterior Crossbite Malocclusion: A Comparative Cross-Sectional Study.

Unilateral posterior crossbite (UXB) is a common, severely asymmetric malocclusion, characterized by maxillary hypoplasia and masticatory dysfunction. The aim of this research is to evaluate the asymmetry of mandibular condyles and rami in children with UXB. This comparative cross-sectional study included 33 children with UXB (girls = 15, boys = 18; mean age ± SD = 8.0 ± 1.3 years.months]) and 33 age- and gender-matched controls (girls = 15, boys = 18; mean age ± SD = 8.4 ± 1.3 years.months]). Pre-treatment OPGs were analyzed by comparing the height of condyles and rami between the sides using the method by Habets et al. (1988); the result was considered significant if the degree of asymmetry was >6%. Children with UXB showed a significantly increased asymmetry of mandibular condyles (mean ± SD = 10.7% ± 9, p < 0.001), but not of rami (mean ± SD = 1.9% ± 2.3), compared to controls. The rami did not show significant asymmetry in either group. The presence of an increased condylar asymmetry index in a developing patient with unilateral posterior crossbite is a sign of altered skeletal growth and should be considered in the diagnostic process and treatment plan.

Effects of Contact Sports on Temporomandibular Disorders: An Observational Study.

The study investigated the prevalence of temporomandibular disorders in 100 competitive athletes in contact sports, equally grouped by the practiced game: Soccer (SoG), Rugby (RG), American Football (AFG), Boxing (BoG), Basketball (BaG), compared to a randomly control group of 20 non-athletes (CG). Symptoms and signs were examined according to the standardized Diagnostic Criteria for Temporomandibular Disorders through a questionnaire and clinical evaluation. Arthralgia showed significant differences between RG and CG and between AFG and CG (p < 0.05). Study groups reported masticatory muscle pain during function, neck and shoulder pain more frequently than CG, except for BoG. Closing click was significantly more present in study groups than CG, while crepitation was significantly higher only in RG and AFG. The deviation was wider in SoG, RG and AFG compared to CG (p < 0.05). Tukey's multiple comparisons test showed a statistically significant reduction in right laterotrusion in RG vs. CG (p < 0.05); the comparison showed a decrease in right laterotrusion in RG vs. SoG and BoG (p < 0.05), a decrease in endfeel in RG vs. CG, BaG and AFG (p < 0.05). The data seem to support a relationship between the prevalence of TMD symptoms and signs in competitive athletes in contact sports, especially in RG and AFG compared to CG.

Chewing Patterns and Muscular Activation in Deep Bite Malocclusion.

BACKGROUND: Deep bite, a frequent malocclusion with a high relapse rate, is associated with craniofacial features that need to be considered in the course of orthodontic treatment. METHODS: This study included 81 patients with deep bite malocclusion (11.4 ± 1.1 [yr.mo]; M = 32 and F = 49), and 14 age- and gender-matched controls (9.11 ± 1 [yr.mo]; M = 5 and F = 9). The patients with deep bite malocclusion were treated with functional therapy. The chewing cycles and masticatory muscle EMG activity were recorded concomitantly before treatment in both groups (n = 95). Following correction of the malocclusion, a second recording took place (n = 25). RESULTS: The kinematic variables showed the same dependency on bolus hardness in those with deep bite and in the controls. The masticatory muscle EMG activity was increased in those with deep bite, but decreased as a result of functional treatment. The chewing patterns showed a tendency towards a reduced lateral component, which significantly increased after treatment, indicating that functional therapy impacts the neuromuscular coordination of mastication, as well as dental positioning. CONCLUSIONS: Deep bite is a complex malocclusion, involving alterations in chewing and masticatory muscle activity. Orthognathodontic treatment should not only consider and correct the teeth position, but should also address muscular hyperactivity.

Temporomandibular Disorders and Oral Features in Idiopathic Inflammatory Myopathies (IIMs) Patients: An Observational Study.

Aim: Inflammatory idiopathic myopathies (IIMs) are inflammatory processes affecting skeletal musculature and extramuscular organs. Temporomandibular disorders (TMD) involve jaw muscles and temporomandibular joint. The aim of this observational study was to investigate the prevalence of the main TMD symptoms and signs as well as oral implications in IIM patients. Methods: The study group included 54 patients (42 women and 12 men), 22 of whom affected by dermatomyositis (DM), 29 by polymyositis (PM) and 3 by inclusion body myositis (IBM). A group of 54 patients not affected by this disease, served as CG. Oral and TMD signs and symptoms were evaluated by means of a questionnaire and through clinical examination. Results: About oral symptoms, the study group complained more frequently dysgeusia, with loss of taste or unpleasant taste (p<0.0001) and feeling of burning mouth (9.4% versus 0 controls). Xerostomia was more prevalent in the study group respect to the CG (p<0.0001). Dysphagia was reported by 48.1% of IIM patients while was absent in CG (p<0.0001). About oral signs, cheilitis (p<0.05) and oral ulcers (p<0.05) were significantly more frequent in CG. As regard to TMD symptoms, arthralgia and tinnitus didn't showed significant differences between the two groups, while neck/shoulders and masticatory muscle pain was significantly more referred in IIM patients than in the CG (p<0.05). About TMJ signs, sounds were overlapping in the two groups: click=11.1% in both IIM patients and CG (p>0.05), crepitation in 11.1% of IIM and 9.3% of controls (p>0.05). No significant difference was detected about deflection (9.3%, p>0.05), while deviation was wider in CG (p<0.05). Active opening and lateralities showed no significant differences, while endfeel was significantly increased in IIM group for a higher presence of muscular contracture. Bruxism was present only in CG. Conclusion: The data collected from this observational study seem to support the existence of a relationship between the prevalence of TMD symptoms and signs as well as oral features in patients with myositis. A remarkable reduction of salivary flow and dysphagia were more frequent and severe in IIM patients, as well as muscle contracture and myofacial pain evoked by palpation, this result being highly significant.

Juvenile/Adolescent Idiopatic Scoliosis and Rapid Palatal Expansion. A Pilot Study.

The question of whether orthodontic therapy by means of rapid palatal expansion (RPE) affects the spine during development is important in clinical practice. RPE is an expansive, fixed therapy conducted with heavy forces to separate the midpalatal suture at a rate of 0.2-0.5 mm/day. The aim of the study was to evaluate the influence of RPE on the curves of the spine of juvenile/adolescent idiopathic scoliosis patients. Eighteen patients under orthopedic supervision for juvenile/adolescent idiopathic scoliosis and independently treated with RPE for orthodontic reasons were included in the study: Group A, 10 subjects (10.4 ± 1.3 years), first spinal radiograph before the application of the RPE, second one during the orthodontic therapy with RPE; Group B, 8 patients (11.3 ± 1.6 years), first radiograph during the use of RPE second one after the removal. Group A showed a significant worsening of the Cobb angle (p ≤ 0.005) at the second radiograph after RPE. Group B showed a significant improvement of the Cobb angle (p = 0.01) at the second radiograph after removal of RPE. Based on the results, the use of RPE during adolescence might influence the spinal curves of patients with idiopathic scoliosis.

Evaluation of masticatory function in patients with cleft lip and/or palate.

The aim of this study was to evaluate the masticatory pattern in children with cleft lip and/or palate (CL/P) through investigation of the prevalence of reverse sequencing chewing cycles. The study group included 18 patients with CL/P (mean age: 7.4 yr, SD: 1.4 yr), 15 of whom had dental crossbite. The controls included a group of 18 non-CL/P children with the same types of crossbite as the study group (mean age: 7.2 yr, SD: 1.5 yr) and a group of 18 non-CL/P subjects with normal occlusion (mean age: 9.8 yr, SD: 1.9 yr). Mandibular movements during chewing of soft and hard bolus were recorded with a kinesiograph. Kinematic signals were analysed using a custom-made software. A statistical analysis was performed to compare the degree of reverse-sequencing chewing cycles between patients and controls (Kruskal-Wallis test with Dwass-Steel-Critchlow-Fligner pairwise comparisons post hoc test). A significant difference between patients with CL/P and non-CL/P subjects with normal occlusion was highlighted on the left side of mastication, which was the side with the higher prevalence of crossbite with both types of bolus. No statistical differences were found between CL/P patients and healthy controls with crossbite. Cleft-affected patients with posterior crossbite exhibited an anomalous masticatory pattern with increased reverse chewing cycles on the crossbite side.

The influence of food hardness on the physiological parameters of mastication: A systematic review.

OBJECTIVE: This systematic review had the purpose to collect existing data concerning the influence of food hardness on mastication in adults. DESIGN: The review was listed with PROSPERO (CRD42017069760) and was directed following with PRISMA and CRD (Centre for Reviews and Dissemination, University of York) statement. A database search of articles issued from 1998 up to December 2018 was carried-out using four databases: Pubmed, Cochrane Library, Web of Science and Scopus. The lists of references of the articles selected for the review were read to identify any other relevant studies. The included publications were analysed for level of evidence, study design, sample characteristics, test of mastication, primary outcomes and key results. A quality assessment of the articles included in the review was performed. RESULTS: 1686 articles were found through database searching. The studies that complied with all the inclusion criteria and were considered for the conclusive analysis were 38 and their methodological quality was scored as moderate/low. The findings of the analysed articles were consistent, despite the presence of different methodologies and the lack of a complete control of the bias. They revealed that the majority of the chewing parameters, which were gathered in four groups: 1) number of cycles, 2) sequence duration, 3) muscle activity and 4) coordination and amplitudes and shape of mandibular displacements, increased in the transition from soft to hard food. CONCLUSIONS: Hard-diet in adults has an impact on the masticatory function increasing almost all the physiological masticatory parameters, muscle coordination and changes of masticatory side.

Altered mastication adversely impacts morpho-functional features of the hippocampus: A systematic review on animal studies in three different experimental conditions involving the masticatory function.

Recent results have established that masticatory function plays a role not only in the balance of the stomatognathic system and in the central motor control, but also in the trophism of the hippocampus and in the cognitive activity. These implications have been shown in clinical studies and in animal researches as well, by means of histological, biochemical and behavioural techniques. This systematic review describes the effects of three forms of experimentally altered mastication, namely soft-diet feeding, molar extraction and bite-raising, on the trophism and function of the hippocampus in animal models. Through a systematic search of PubMed, Embase, Web of Science, Scopus, OpenGray and GrayMatters, 645 articles were identified, 33 full text articles were assessed for eligibility and 28 articles were included in the review process. The comprehensiveness of reporting was evaluated with the ARRIVE guidelines and the risk of bias with the SYRCLE RoB tool. The literature reviewed agrees that a disturbed mastication is significantly associated with a reduced number of hippocampal pyramidal neurons in Cornu Ammonis (CA)1 and CA3, downregulation of Brain Derived Neurotrophic Factor (BDNF), reduced synaptic activity, reduced neurogenesis in the Dentate Gyrus (DG), glial proliferation, and reduced performances in behavioural tests, indicating memory impairment and reduced spatial orientation. Moreover, while the bite-raised condition, characterized by occlusal instability, is known to be a source of stress, soft-diet feeding and molar extractions were not consistently associated with a stress response. More research is needed to clarify this topic. The emerging role of chewing in the preservation of hippocampal trophism, neurogenesis and synaptic activity is worthy of interest and may contribute to the study of neurodegenerative diseases in new and potentially relevant ways.

Temporomandibular Disorders and Oral Features in Systemic Lupus Erythematosus Patients: An Observational Study of Symptoms and Signs.

Aims: Systemic Lupus Erythematosus (SLE) is a connective tissue disease characterized by a wide range of pleomorphic pictures, including mucocutaneous, renal, musculoskeletal and neurological symptoms. It involves oral tissues, with hyposalivation, tooth decay, gingivitis, angular cheilitis, ulcers and glossitis. Temporomandibular disorders represent a heterogeneous group of inflammatory or degenerative diseases of the stomatognatic system, with algic and/or dysfunctional clinical features involving temporomandibular joint (TMJ) and related masticatory muscles. The aim of this study was to investigate the prevalence of oral manifestations and temporomandibular disorders (TMD) in SLE patients (Lp) compared with a control group. Methods: Fifty-five patients (9 men and 46 women) with diagnosed Lupus were recruited in the study group. A randomly selected group of 55 patients, matched by sex and age, served as control group. The examination for TMD symptoms and signs was based on the standardized Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) through a questionnaire and clinical examination. Results: Lupus patients complained more frequently (95.8%) of oral and TMJ symptoms (dysgeusia, stomatodynia, masticatory muscle pain during function, neck and shoulder muscles pain and presence of tinnitus) but only xerostomia (χ2=4,1548 p=0,0415), temple headache (χ2=4,4542 p=0,035) and the sensation of a stuck jaw (Mid-p-test p=0,043) were significant. About signs, cheilitis (p=0,0284) oral ulcers (χ2=4,0104 p=0,045) and fissured tongue are significantly more frequent in study group. The salivary flow was significantly decreased in the study group respect to the control one (p<0.0001). As regard to the oral kinematics, restricted movements (RM) in protrusion and left lateral movement were significantly different between study group and controls. In particular, 85,2% of Lp showed limited protrusion versus 56,4% of controls (χ2= 10,91 p<0,001); 59,3% of Lp had also a limitation during left lateral movement versus 47,3% of controls (T=2,225 p=0,0282). About bruxism, only the indentations on the lateral edges of the tongue were found in Lp group (72,7%), with a significant difference respect to controls (χ2=7,37 p=0,007). Conclusions: While masticatory muscles have an overlapping behavior in both groups, the findings collected show a more severe TMJ kinematic impairment in Lp than in controls, with protrusion and left lateral movements significantly different. In addition, a remarkable reduction of salivary flow has been detected in Lp compared to controls. In conclusion, this autoimmune disease seems to play a role in oral manifestations and TMJ disorders, causing an increase in orofacial pain and an altered chewing function.

Chapter 14: Impact of Oral Health on Diet/Nutrition.

An individual's oral health status has a profound impact on his/her acquisition and utilization of nutrients and interchangeably the nutrients an individual consumes determine the state of oral health by preventing tooth loss and oral diseases. Oral diseases have a considerable impact on the masticatory function which is a critical first step in oral processing of food materials for nutrient procurement. Specifically, a section of this chapter is dedicated to the physiology of masticatory function and to the recent acknowledgement of its influence on memory and cognition, both during development and aging. A description of the occlusal and skeletal pathologies that affect the balance of the chewing pattern and related muscular activation is provided. Intact neurocognitive functions and dentition are essential in mastication to achieve coordinated movements of the teeth and tongue to help propel the food material for ingestion and subsequent nutrient absorption. The tongue is equipped with chemoreceptive, gustatory cells, which modulate taste perception and contain metabolic hormones mediating satiety. Concomitantly, salivary processes, which are stimulated with the anticipation of food ingestion and those which occur during mastication of the food material, initiate digestive enzymes in the mouth and stomach and are important in affecting appetite and food bioavailability. Therefore, oral structures such as the dentition, tongue, and saliva in the context of mastication and nutrient acquisition will be reviewed as well as their impact on food choice and subsequent nutritional status.

Immunofluorescence Evaluation of Myf5 and MyoD in Masseter Muscle of Unilateral Posterior Crossbite Patients.

A unilateral posterior crossbite is a malocclusion where the low activity of the affected masseter muscle is compensated by the contralateral muscle hypertrophy. It is still unknown if, in the same condition, myogenesis with new fibre formation takes place. AIM: the aim of the present study was to evaluate the expression of myogenesis markers, such as Myf5 and MyoD, in masseter muscles of unilateral posterior crossbite patients. MATERIALS AND METHODS: biopsies from fifteen surgical patients with unilateral posterior crossbites have been analysed by immunofluorescence reactions. The results show the expression of Myf5 and MyoD in the contralateral muscle but not in the ipsilateral one. Moreover, statistical analysis shows the higher number of satellite cells in the contralateral side if compared to the ipsilateral one. CONCLUSIONS: these results suggest that in contralateral muscle, hyperplastic events take place, as well as hypertrophy.

Condylar long axis and articular eminence in MRI in patients with temporomandibular disorders.

OBJECTIVE: To compare morphologic findings in MRI and skeletal divergence of a group of patients with temporomandibular joint disorders (TMD) subdivided into condylar symmetric and asymmetric. METHODS: Fifty-nine adults (26.7 years old) with TMD were retrospectively recruited. Condylar height symmetry was evaluated by orthopantomography (Habets's method) and used to divide patients into Symmetric and Asymmetric groups; skeletal divergence was assessed on lateral cephalograms. MRI was used to evaluate the condylar long axis' angle, the glenoid fossa morphology, and the degree of disc displacement. RESULTS: Asymmetric subjects showed a hyperdivergent skeletal pattern (p = 0.036), asymmetric condylar long axis (p = 0.018), and deeper (p = 0.025) and asymmetric (p = 0.001) glenoid fossa compared to symmetric subjects. CONCLUSION: Patients with TMD and condylar asymmetry diagnosed with orthopantomography are more likely to show hyperdivergent skull in cephalometry, condylar asymmetry of both height and major axis, and a steeper glenoid fossa in MRI.

Thoracic-lumbar-sacral spine sagittal alignment and cranio-mandibular morphology in adolescents.

PURPOSE: The relationship between thoracic-lumbar-sacral spine sagittal alignment and craniofacial morphology is still controversial. Evidence-based results are difficult to obtain and scientific studies are inhomogeneous. The aim of this study was to investigate the difference of thoracic-lumbar-sacral spine posture and cephalometric values comparing two groups of subjects with different cranial structure in the sagittal plane. METHODS: Eighty-one subjects were consecutively selected and divided into two groups, according to the orientation of the condyle-orbital plane (CoOr) with respect to the superior maxilla (SpP): Group1: 49 subjects 11.6 (2.1) years showing posterior-rotation of CoOr: SpP^CoOr ≤ -2°, -4.1°(2.1°); Group2: 32 subjects 12.9 (2.3)years showing anterior-rotation of CoOr: SpP^CoOr ≥ 2°, 3.7°(1.9°). Each patient underwent in blinding, Spinal Mouse recording and cephalometry of the skull. RESULTS: Group1 showed a significant forward tilting of the spine 4.4°(1.8°) with respect to Group2 2.4°(1.3°) (p < 0.0001) and higher values related to the vertical dimension of the skull: higher maxillary divergency (p < 0.0001), steep occlusal plane (p < 0.0007), higher gonial angle (p < 0.001). DISCUSSION: The results of this study showed a difference in the thoracic-lumbar-sacral spine inclination between groups with different craniofacial morphology. The achievement of this outcome is important to improve our multidisciplinary evaluation and treatment planning.