[Temporomandibular joint, occlusion and bruxism]

Relationship between natural or iatrogenic malocclusions and temporomandibular disorders: A case control study

OBJECTIVE

To investigate the link between malocclusions and temporomandibular disorders (TMD) with a focus on iatrogenic malocclusion. Other etiologies of TMD (oral parafunctions) were also assessed.

METHODS

The prevalence of malocclusions was correlated in two groups: patients with TMD (case group) and patients without TMD (control group). Malocclusions involving dental care were specified. Parafunctions in the case group were assessed.

RESULTS

A statistically significant association between TMD and overbite >4 mm, interferences in laterotrusion, and absence of Angle Class I was shown. A potential deleterious effect of iatrogenic malocclusions was highlighted.

CONCLUSION

The multifactorial etiology of TMD was confirmed because an association between TMD and three malocclusions was found, and all case patients had parafunction(s). Current recommendations advising first a reversible treatment, TMD care should start with a behavioral re-education to remove parafunctions. However, it is essential to avoid creating iatrogenic malocclusion during dental care.

A pilot investigation of condylar position and asymmetry in patients with unilateral posterior scissors-bite malocclusion based on three-dimensional reconstructive imaging technique

OBJECTIVE

Unilateral posterior scissors-bite (uPSB) malocclusion is common clinically. This study aimed to investigate the condylar morphological alterations and condyle-fossa relationship in patients with uPSB, through cone beam computed tomography (CBCT) and three-dimensional reconstructive imaging technique.

METHODS

A retrospective study was designed to comparatively analyze 95 patients with uPSB between July 2016 and December 2021. They were divided into three subgroups: 12 to 20, 21 to 30, and ≥ 31 years, according the age distribution. The morphological parameters regarding condyle, fossa, and joint space after three-dimensional reconstruction were measured and analyzed by a series of digital software. SPSS 26.0 software package was performed for statistical analysis on data sets, using paired t-test, one-way analysis of variance, Wilcoxon signed-rank sun test, Kruskal-Wallis H test, and Bonferroni correction.

RESULTS

The condylar volume (CV) of scissors-bite side was greater than that of the non-scissors-bite side (CV _A = 1740.68 ± 559.80 mm³ > CV _N = 1662.25 ± 524.88 mm³, P = 0.027). So was the condylar superficial area (CSA) (CSA _A = 818.71 ± 186.82 mm² > CSA _N = 792.63 ± 173.44 mm², P = 0.030), and the superior joint space (SJS) [SJS _A = 2.46 (1.61, 3.68) mm) > SJS _N = 2.01 (1.55, 2.87) mm), P = 0.018], and the anterior joint space (AJS) (AJS _A = 3.94 ± 1.46 mm > AJS _N = 3.57 ± 1.30 mm, P = 0.017). The constituent ratios of the different parts of the bilateral condyles were 23% on the posterior slope, 21% on the top, 20% on the anterior slope, 19% on the lateral slope and 17% on the medial slope, respectively.

CONCLUSION

Due to long-term abnormal occlusion of uPSB, the pathological bite force in temporomandibular joint would cause changes in the shape of the condyle. Among them, CV, CSA, SJS and AJS had significant changes in the scissors-bite status, which has the greatest damage to the posterior slope of the condyloid process.

Oral Health Status and Multiple Sclerosis: Classic and Non-Classic Manifestations—Case Report

Background: Multiple sclerosis is an autoimmune disease of the central nervous system with neurological and motor symptoms that affect the orofacial region. The aim of this work is to present a patient that lacks the three classic orofacial manifestations but has other less common clinical alterations. Case presentation: A 49-year-old female patient diagnosed with long-term relapsing–remitting multiple sclerosis visited the dentist complaining of mild but persistent orofacial pain including the temporomandibular joint and pain not specific to any tooth. She presented mucosal irritation, xerostomia, halitosis, and localized gingivitis. There was excessive wear of the upper and lower incisal edges and the occlusal faces of the upper canines and loss of six teeth due to caries. After a clinical oral examination, the diagnosis was temporomandibular joint disorder, gingivitis, dental hypersensitivity, bruxism, hyposalivation, xerostomia, and halitosis. Conclusions: Patients with multiple sclerosis present classic orofacial manifestations. Although these were not observed in this patient, she had others, such as gingivitis, tooth hypersensitivity, and bruxism. In addition, despite few studies associating a higher prevalence of caries with these patients, the number of carious and missing teeth in this patient highlight the evidence that multiple sclerosis has had a significant impact on the patient’s dental status over the years.

Full-mouth rehabilitation choices depending on amelogenesis imperfecta's type: A familial case report

Amelogenesis imperfecta, a rare disease, represents inherited, congenital defects that primarily affect enamel with esthetic and functional impairment affecting everyday life. We present oral rehabilitation of a mother and her son, respectively, suffering from an hypoplastic and an hypocalcified form of AI.

The effectiveness of an occlusal disclosure sheet to diagnose sleep bruxism: A pilot study

OBJECTIVE

To evaluate the utility of vacuum-pressed, BruxChecker^® sheets for the diagnosis of sleep bruxism.

METHODS

Twenty subjects participated in this study. Tooth contact during sleep was recorded using a 0.1 mm-thick polyvinyl chloride sheet called BruxChecker^®. The area of the BruxChecker^® in which the red dye was removed was measured. In addition, the EMG activity of the masseter muscle during sleep was recorded. The numbers of bruxism bursts and episodes were counted, and their correlations with the peeled area of the red dye on the BruxChecker^® were evaluated.

RESULTS

The number of bruxism bursts and episodes/hr significantly correlated with the peeled area at all cut-off values. The peeled area significantly correlated with the number of phasic type bruxism episodes but not with tonic or mixed type bruxism episodes.

DISCUSSION

Since the BruxChecker^® peeled area reflected phasic type sleep bruxism, the sheets may be useful in sleep bruxism screening.