Andrea Bargellini; Tommaso Castroflorio; Federica Casasco; Maria Giacone; Francesco Garino; Giovanni Cugliari; Andrea Deregibus
Abstract
Background: In the last years an increasing number of patients have sought for comfortable and aesthetic alternatives to fixed appliances. Aligners, due to the protection against tooth wear, can be compared to occlusal splints used in patients suffering from sleep bruxism (SB). The aim of the study was ...
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Background: In the last years an increasing number of patients have sought for comfortable and aesthetic alternatives to fixed appliances. Aligners, due to the protection against tooth wear, can be compared to occlusal splints used in patients suffering from sleep bruxism (SB). The aim of the study was to analyze the effects of clear aligners on SB episodes using a validated portable device (Bruxoff®, OTBioelettronica, Torino, Italy) allowing a simultaneous recording of electromyographic signals from both the masseter muscles as well as heart frequency to evaluate variation on SB activity.
Methods: Forty patients were analyzed for the study. Twenty of them were assigned to orthodontic treatment with clear aligners (Invisalign®, Align Technology). The other twenty patients were used as control group observed for a period of twelve months. Intra-group and inter-group variances were analyzed by using a two-way ANOVA test. For each analysis a P < 0.05 was set. Results: After the first month of clear aligners therapy, all patients in the case group showed a significant reduction in the number of SB episodes (P < 0.05). However, after three months SB values returned to baseline levels. The number of tonic contractions were reduced even after three months of orthodontic treatment (P < 0.05).
Conclusions: While clear aligners seem to be capable to reduce clenching, i.e. occlusal load, in SB patients, the grinding activity seems to be not influenced by those appliances at least in the short term of the present investigation.
Giulia Gay; Serena Ravera; Tommaso Castroflorio; Francesco Garino; Giovanni Cugliari; Andrea Deregibus
Abstract
Background: Existing literature indicates that orthodontics patients are more likely to have severe apical root shortening, interesting mostly maxillary, followed by mandibular incisors.
Objectives: The aim of the present study was to investigate the incidence and severity of root resorption (RR) in ...
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Background: Existing literature indicates that orthodontics patients are more likely to have severe apical root shortening, interesting mostly maxillary, followed by mandibular incisors.
Objectives: The aim of the present study was to investigate the incidence and severity of root resorption (RR) in mandibular incisors of adult patients treated with aligners.
Methods: The study group consisted of 71 adult healthy patients (mean age 32.8 ± 12.7) treated with aligners (Invisalign®, Align Technologies, San Jose, CA, USA) for the intrusion of the lower incisors. Root and crown lengths of a total of 279 lower incisors were measured in panoramic radiographs at the beginning (T0) and at the end (T1) of aligner therapy. Individual root-crown-ratio (RCR) of each tooth and therefore the relative changes of RCR (rRCR) were determined. Results: 44% of the 279 measured teeth presented a reduction of the pre-treatment root length. A reduction in percentage of > 0% up to 10% was found in 26.76% (n = 76), a distinct reduction of > 10% up to 20% in 12.32% (n = 35) of the sample. 4.58% (n = 13) of the teeth were affected by a clinically relevant reduction (> 20%).
Conclusions: Orthodontic treatment with Invisalign® aligners could led to RR in cases in which intrusion of the lower incisors is planned. However, the incidence of RR is comparable to data described in case of application of light forces with fixed appliances, and considerably lower than what has been described for traditional comprehensive orthodontic treatments.