HALITOSIS WITH FIXED ORTHODONTIC APPLIANCE VS REMOVABLE ORTHODONTIC ALIGNERS : A PILOT STUDY in a stastically significant way ( p = 0,003 ), which led to a statistically significant increase of the plaque and tongue coating indexes , and confirmed the suspected positive correlation between halitosis and fixed orthodontic appliances 5 . The brackets and ligatures have a negative effect on natural cleaning by creating retention areas for plaque , making the mechanical cleaning of the teeth and gingiva by the tongue and lips more difficult , and increasing the viscosity of the saliva 6-8 . It has been stated that the accumulation of plaque and the increase in bacterial count 9 and tongue coating 10 are clearly also involved in the formation of halitosis . There are also plenty of studies about the effect of orthodontic treatment on the periodontium 11 , 12 . Determining the bracket system that causes the less destructive biologic effect has gained importance today . In this perspective , studies have been conducted on self-ligating brackets ( SLB ), with conflicting opinions . The absence of ligatures should provide fewer retentive sites than other bracket ligation types 13 but , on the other hand , this theoretical advantage may be eliminated in reality because SLB consist in opening and closing mechanisms that may provide additional plaque retention sites 14 , 15 . Instead , with aligner devices , oral hygiene habits were very good 16 . The use of removable orthodontic appliances , particularly invisible aligners , allows adequate oral hygiene and can reduce the risk of dental and periodontal complications such as white spot lesions , caries and periodontitis 17 . About the correlation between halitosis and orthodontic aligner treatment , it has been shown that this kind of treatment ( Invisalign ®) is characterized by only minimal impairment of overall oral health and the associated quality of life . Neither halitosis , nor oral dryness , nor high plaque or gingival index measurements were observed 4 . This is a very interesting study but it does not compare orthodontic aligners and fixed orthodontic appliances , as predisposing conditions to halitosis . The aim of the present study is to evaluate the presence of volatile sulfur compounds ( VSCs ) in patients with orthodontic aligner compared to patients with orthodontic fixed appliance . The VSC consisting of hydrogen sulfide , dimethyl sulfide , and especially methyl mercaptan released through the proteolytic degradation of saliva , exfoliated epithelium , food debris , gingival crevicolar fluid , plaque , postnasal drip , sulfur-containing amino acids , and peptides in the blood by the anaerobic microorganisms found in the oral cavity are effective on the formation of halitosis 18 . The null hypothesis is that there are no differences in oral volatile sulfur compounds ( VSC ) emissions between patients with fixed orthodontic appliances and orthodontic aligners .
2 . Materials and Methods 2.1 . Study Sample Fixed Orthodontic and Invisalign ® patients were selected consecutively with the following characteristics : age between 18 and 39 years old ,
good general health , non-smokers , absence of systemic diseases , absence of gastro esophageal reflux , no eating disorders ( DAC ) and not pregnant . The fixed orthodontic treatment we intended was a superior and inferior multi-brackets system at least from first molar to first molar , instead , the Invisalign treatment consisted of superior and inferior aligner devices . Both treatments have to be started since , at least , three months subjects were involved in the study . We considered the following characteristics as exclusion criteria : individuals with systemic diseases , medical treatments , cuts , sores , lesions of the mucosa and wounds , bearers of crowns , veneers or bridges on the upper incisors and active carious lesions . We also left out individuals who declared to not brush their teeth at least three times a day , to not use dental floss and / or dental picks and , in Invisalign ® cases , to not clean aligners with their personal toothbrush and toothpaste ( with RDA less than 100 ) at least two times a week and to not put them in immersion solution of sodium sulfate carbonate at least once a week 19 , 20 . Among these patients10 patients with aligners ( aligners group – AG ) and - 10 patients with fixed orthodontic appliance ( fixed group – FG ) were selected . The study was carried out in accordance with the principles of the Declaration of Helsinki and in compliance with Good Clinical Practice . The study protocol was reviewed and approved by the University of Insubria Research Centre Cranio Facial Disease and Medicine Institutional Ethical Committee . Before taking part in the study each patient was required to sign an informed consent form to which a detailed description of the study protocol was attached . These individuals were asked to come for the orthodontic control , at least an hour after performing the oral hygiene procedures , and for VSC measurements . 2.2 . Methodology This experiment aims to detect the presence of halitosis with a gaschromatograph OralChroma™ ( Fig . 1 ).
Figure 1 . Gaschromatograph OralChroma™
The patient must keep a sterile disposable 1 ml syringe in the oral cavity for 60 seconds , with his mouth closed and without contaminating it with saliva ( Fig . 2 a-c ). After 60 seconds , the patient must open and close the syringe plunger 2 times ,
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