Angle各类错及正常牙弓对称性分析与比较

目的　对Angle各类错及正常的牙弓对称性进行分析和比较。方法　以 4组不同类型错及正常者共 30 0人为研究对象 ,采用YM 2 115三维测量仪精密测量其模型 ,用圆锥曲线模拟牙弓形态 ,利用曲线方程的参数之一旋转角 (θ)分析牙弓对称性。结果　无绝对对称的牙弓 ,牙弓不对称也无固定的方向。正常牙弓基本是对称的 ,存在极小范围的不对称。而错总体说来比正常牙弓不对称发生的频率及程度高 ;除ClassIII外 ,下牙弓比上牙弓易出现不对称。各组中ClassII2和ClassIII不对称的发生频率均较高。结论　不同类型错者牙弓不对称发生的频率及程度有一定差异     

Effect of palatine tonsil hypertrophy on tongue posture and maxillofacial dentition: A pharyngeal airway computational fluid dynamics study

ObjectivesThis study aimed to clarify the effect of palatine tonsil hypertrophy-induced ventilation obstruction on maxillofacial dentition morphology using computational fluid dynamics (CFD) to represent tongue posture and maxillofacial dentition three dimensionally.Materials and methodsWe analyzed data of 20 patients with tonsil hypertrophy (tonsil hypertrophy group (TG); 9.0 years old, seven boys) and a comparison group (CG) of 20 patients without tonsil hyperplasia (comparison group; 9.4 years old, 10 boys). Cone-beam computed tomography and CFD data were used to assess the effects of palatine tonsil hypertrophy on pharyngeal airway ventilation, tongue posture, and morphology of the maxillofacial dentition.ResultsThe TG exhibited significantly greater depth, narrower width, smaller cross-sectional area of the pharyngeal airway, and narrower maxillary dental arch with Class II than the CG. Additionally, the tongue was positioned significantly more anteriorly and inferiorly in the TG than that in the CG.ConclusionsOur data suggest that hypertrophy of the palatine tonsils narrows the pharyngeal airway, resulting in a smaller cross-sectional area. Widening of the pharyngeal airway may occur due to compensatory anterior displacement of the tongue to prevent ventilation obstruction. This may decrease palatal support, disturbing the pressure balance of the maxillary molar region between the buccal and palatal sides and resulting in lateral undergrowth of the maxillary bone and narrowing of the maxillary dental arch.     

Oral appliance–generated malocclusion traits during the long-term management of obstructive sleep apnea in adults:: A systematic review and meta-analysis

ObjectivesTo identify malocclusion characteristics generated after using oral appliances (OAs) for at least 5 years for the management of snoring and obstructive sleep apnea (OSA) in adults.Materials and MethodsPubMed, MEDLINE (Ovid), Scopus, CINAHL, and Informit were searched without language restrictions through January 20, 2021. Unpublished literature was searched on ClinicalTrials.gov, the National Research Register, and the Pro-Quest Dissertation Abstracts and Thesis database. Authors were contacted when necessary, and reference lists of the included studies were screened. Risk of bias was assessed through the revised Cochrane Risk of Bias tool for randomized controlled trials (RoB2) and Non-Randomized Studies of Interventions for non-RCTs and uncontrolled before–after studies (ROBINS-I). A random-effects meta-analysis was conducted only on studies that used the same OAs to exclude biomechanical differences. Risk of bias across studies was assessed with the Grading of Recommendations, Assessment, Development and Evaluation tool.ResultsA total of 12 studies were included in the final qualitative synthesis. Eight included studies had high, one had moderate, and three had low risks of bias. Significant progressive decreases of overjet (OJ; −1.43 mm; 95% confidence interval [CI], −1.66 to −1.20) and overbite (OB; −1.94 mm; 95% CI, −2.14 to −1.74) associated with maxillary incisor retroclination and mandibular incisor proclination were reported long term. Although most studies showed no sagittal skeletal changes, some degree of vertical skeletal changes were noted.ConclusionsBased on a very low evidence level, inevitable anterior teeth positional changes seem to be a common long-term adverse effect of OAs. The magnitude of those changes could be considered clinically irrelevant for most pretreatment occlusions, but in occlusions with limited OJ and OB, it may be worth clinical consideration.     

Temporomandibular disorders in prospective orthodontic patients:: Their association with malocclusion severity and impact on oral health–related quality of life

ObjectivesTo determine the prevalence and severity of temporomandibular disorders (TMDs) in prospective orthodontic patients. The association between TMDs and malocclusion severity as well as the impact of TMDs on oral health–related quality of life (OHRQoL) were also examined.Materials and MethodsA total of 350 consecutive patients seeking orthodontic treatment were invited to participate in the study. The presence of TMDs was established with the Fonseca Anamnestic Index (FAI), while malocclusion severity and OHRQoL were evaluated using the Peer Assessment Rating (PAR) index and Oral Health Impact Profile–14 (OHIP-14), respectively. Data were analyzed using chi-square, Kruskal-Wallis, and Mann-Whitney U tests and Spearman''s correlation (P < .05).ResultsOf the 350 patients, 164 consented to participation. Data from 26 participants were excluded because of incomplete entries, and that from 138 subjects (mean age 21.02 ± 5.45 years) were examined. TMD-related symptoms were present in two-thirds of the subjects, with 20.3% experiencing moderate/severe TMDs. While no significant difference in PAR scores were observed between the group with no TMDs and those with TMDs, subjects with TMDs had significantly higher OHIP-14 summary/domain scores than those without TMDs. Although a moderately strong correlation was observed between the FAI and summary OHIP-14 scores (r_s = 0.57), no association was observed between FAI and PAR index scores.ConclusionsThe prevalence of TMD-related symptoms in prospective orthodontic patients was high, emphasizing the importance of screening the masticatory system before initiating orthodontic therapy. Although the presence of TMDs was not associated with malocclusion severity, it had a significant negative impact on OHRQoL.     

A comparison of arch widths in adults with normal occlusion and adults with class II, Division 1 malocclusion

This study compares arch widths and other cast and cephalometric measurements of 36 normal-occlusion subjects (19 males, 17 females) with 39 Class II, Division 1 subjects (20 males, 19 females). None of the subjects had received orthodontic treatment. Analysis of variance demonstrated that subjects with normal occlusion had larger maxillary molar widths, maxillary canine widths, and maxillary alveolar widths than subjects with malocclusion; only male subjects with normal occlusion had larger mandibular molar widths and mandibular alveolar widths than the malocclusion subjects; the normal occlusion and malocclusion groups had similar mandibular canine widths; and when the lower molar and alveolar widths were subtracted from corresponding upper widths, the remainders of the Class II group were negative instead of positive, contrary to the normal group. This revealed a posterior crossbite tendency in the Class II group.     

Three-dimensional comparative evaluation of articular disc position and other temporomandibular joint morphology in Class II horizontal and vertical cases with Class I malocclusion:: A magnetic resonance imaging study

ObjectiveTo evaluate and compare articular disk position, condylar position, and joint spaces in Class II vertical, Class II horizontal, and Class I cases. The purpose was to assess the potential for development of temporomandibular disorders (TMDs) in the three groups.Materials and MethodsA sample of 75 cases, 25 cases in each group of Class I, Class II vertical, and Class II horizontal, were selected based on inclusion and exclusion criteria. Magnetic resonance imaging (MRI) assessments were made with a 1.5-Tesla basic system with a closed-mouth technique for evaluating articular disk position in the sagittal and transverse planes, condylar position, and joint spaces in the sagittal plane. Philips 3.0 software was used to analyze the MR images.ResultsThere was evidence of alterations in the temporomandibular joint (TMJ) morphology in both Class II vertical and Class II horizontal cases, with maximum discrepancy in Class II vertical cases. MRI evaluation suggested a tendency for antero-medial disk displacement with anteriorly positioned condyles in Class II vertical cases. The discrepancy was milder in the Class II horizontal group.ConclusionsClass II vertical cases are more susceptible to the development of TMDs and should be subjected to TMJ evaluation before starting any orthodontic treatment to intercept and prevent a mild asymptomatic TMD from developing into a more severe form. Class II vertical cases should be subjected to MRI evaluation before starting any orthodontic treatment.     

Comparison of quality of life and psychological distress in patients with tongue cancer undergoing a total/subtotal glossectomy or extended hemiglossectomy and free flap transfer: a prospective evaluation

The aim of this study was to assess changes in the quality of life and psychological distress of patients with tongue cancer undergoing total/subtotal glossectomy (TG) or extended hemiglossectomy (HG) and free flap transfer. Differences between the two groups were compared using the Short Form 8-Item Health Survey (SF-8) and Hospital Anxiety and Depression Scale (HADS). Of the 43 patients with tongue cancer, 24 (56%) underwent TG and 19 (44%) underwent HG. The general health and social functioning scores in the SF-8 and depression in the HADS were significantly worse in the TG group than in the HG group at 12 months after surgery, indicating that patients in the TG group may experience social isolation and psychological distress, and have difficulty in employability even 12 months after surgery. In contrast, all items of the SF-8 in the HG group were nearly equal to those in the general population. Due to the extensive psychological impact on patients with tongue cancer who are planned for an extended resection, curative surgery with free flap transfer and multidisciplinary psychiatric support are essential to improve quality of life and manage psychological distress.     

Evaluation of occlusion types,pain severity,and onset of complaints in 127 patients with temporomandibular disorders: A retrospective study

ABSTRACT

Objective: The aims of this study are to evaluate if occlusal types affect the type of temporomandibular disorders and if the onset of complaints are related to the type of internal derangements.

Methods: One hundred thirty-four patients were evaluated. Occlusion types were grouped as Angle Class I, II, and III. The temporomandibular disorders were classified as masticatory muscle disorders, anterior disc dislocation with reduction, and anterior disc dislocation without reduction.

Results: No significant relationships were found between the occlusion types, pain severity, the onset of the complaints, and the temporomandibular disorders. Premature contacts were found to be significantly higher in Class II and Class III patients, but no significant relations were found between premature contacts and temporomandibular disorders.

Discussion: Occlusal features are not discriminant factors in the occurrence of temporomandibular disorders. Also, it cannot be concluded that the longer the patients have temporomandibular disorders, the higher their pain scores will be.     

Association of tongue brushing with the number of fungiform taste buds and taste perception: A preliminary study using confocal laser scanning microscopy in combination with a filter-paper disc method

ObjectiveThe aim of this study was to investigate the association of tongue brushing with the number of fungiform taste buds and taste perception using a confocal laser scanning microscopy in combination with a filter-paper disc method (FPDM).MethodsTwenty-four subjects with or without a habit of tongue brushing (11 males and 13 females, 20–46 years old) participated in this study. Nine of the 24 subjects had no habit of tongue brushing (Group 1, n = 9). Fifteen subjects had a habit of tongue brushing, and the brushing regions of the tongue were as follows: central region (Group 2, n = 7), or entire region (Group 3, n = 8) of the tongue dorsum. Using confocal laser scanning microscopy, the average number of taste buds per fungiform papilla (FP) was counted. Taste perception was evaluated using an FPDM. These observations were performed in the midlateral region of the tongue since the distribution of fungiform papillae is large in the midlateral region compared to that in the central region.ResultsThe subjects in Group 3 showed a significantly decreased number of fungiform taste buds compared to Group 1 and Group 2. Group 3 also showed significantly higher FPDM scores than the other two groups.ConclusionsExcessive tongue brushing of the entire tongue dorsum, including the midlateral region, may have an association with the decreased number of FP and taste buds and decreased taste sensation. To avoid these conditions, instituting proper tongue brushing methods, such as limiting it to the central region of the tongue and using a light touch, is suggested and is important for the subjects who are eager to participate in tongue brushing.     

Comparison of muscle activity between subjects with or without lip competence: Electromyographic activity of lips,supra- and infrahyoid muscles

Aim: This study compares the electromyographic (EMG) activity of the muscles from the lips and hyoid bone in subjects with or without lip competence.

Methodology: Two groups of 20 subjects each, with or without lip competence were studied. EMG activity of the superior orbicularis oris (SOO), inferior orbicularis oris (IOO), suprahyoid (SH) and infrahyoid (IH) muscles was recorded with the subject seated in the upright position during the following tasks: (1) at rest; (2) speaking; (3) swallowing; (4) forced deep breathing; (5) maximal voluntary clenching; and (6) chewing.

Results: EMG activity was significantly higher in subjects without competent lips than with competent lips in the SOO and IOO muscles during tasks 3 and 4, SOO during task 2 and IOO during task 6. EMG activity was similar in the SOO and IOO muscles during tasks 1 and 5, SOO during task 6 and IOO during task 2. Activity of the SH and IH muscles was similar in both groups for all tasks.

Conclusions: Higher activity in subjects without competent lips implies a higher muscular effort due to the requirement of lip sealing during functional activities. Hyoid muscular activity was not modified by the presence or absence of lip competence.     

A four-year longitudinal study of palatal plate therapy in children with Down syndrome: effects on oral motor function,articulation and communication preferences

The orofacial function in 20 children with Down syndrome was evaluated after 4 years of palatal plate therapy in 9 of the children (PPG); the remaining 11 were untreated age-matched controls (CG). All 20 children had received continuous orofacial physical therapy from their speech therapist during the treatment period. A clinical extra- and intraoral examination was performed, including oral motor function, facial expression, the occurrence of malocclusions, and hypertrophic tonsils. A questionnaire requesting data on breathing patterns, drooling, eating problems, and communicative preferences was answered by the parents. An articulation assessment was performed by two speech and language pathologists blinded to the treatment status of the children in order to find out whether the palatal plate had stimulated to improved oral speech behavior. The results for oral motor function showed significant differences between the groups in favor of the PPG for the summary variables for: visible tongue (P < 0.01), visible tongue during non-speech periods (P < 0.05), and lip-rounding during spontaneous speech (P < 0.01). During non-speech time, the PPG had their mouths open significantly less than the CG (P < 0.05). Expressivity of facial expression on a visual analog scale in the PPG scored 75.6 ± 13.3 compared to 51.8 ± 25.7 in the CG (P < 0.05). The intraoral examination showed that 6/9 children in the PPG and 7/11 in the CG had enlarged tonsils, resulting in more than 50% inter-tonsillary space reduction. Despite these findings, and no significant differences between the groups with respect to mouth/nose breathing, nocturnal snoring was significantly less in the PPG than in the CG (P < 0.05), according to the parental questionnaire. After 4 years of palatal plate therapy, orofacial function had improved significantly in the 9 PPG children and specifically in terms of tongue position and lip activity.