Impact of Bracket Design and Oral Hygiene Maintenance on Halitosis in the Orthodontic Patient

Background

Halitosis refers to the condition of malodor of the oral cavity (2009). Halitosis is
estimated to affect 50% of the population with varying degrees of intensity and etiology
(Meskin 1996). In 80% of all cases halitosis is secondary to underlying oral conditions
(Miyazaki, Sakao et al. 1995).The etiology of halitosis is often caused by food debris and
biofilm buildup on the teeth and tongue, deep periodontal pockets, severe carious lesions
and poor dental restorations (Yaegaki and Sanada 1992; Morita and Wang 2001; Morita and Wang
2001). The odor emanating from the oral cavity is produced by microbial putrefaction of
residual oral debris, resulting in production of malodorous Volatile Sulfur Compounds (VSCs)
(Porter and Scully 2006). Previous studies have shown that the amount of VSCs in breath
increases with the number, depth, and bleeding tendency of the periodontal pockets
(Quirynen, Zhao et al. 2002). Therefore plaque control, which directly impacts periodontal
health, is an important factor in the control of halitosis.

Halitosis can be diagnosed by 3 primary methods (Yaegaki and Coil 2000; van den Broek,
Feenstra et al. 2007)

1. Organoleptic method: The primary reference standard for the detection of oral malodor
is the human nose and this method involves direct sniffing of the expired air by a
trained judge. This assessment can also be done by scraping the posterior dorsum of the
tongue with a spoon and smelling the contents.

2. Gas chromatography: This is the method of choice for researchers. It allows for the
identification and quantification of individual components within the air sample. The
measurement of VSC can be obtained and differentiated with using samples from saliva,
tongue coating and breath. Disadvantages to this method are high cost and the
requirement of highly trained personnel. This assessment cannot be done chairside and
requires a separate laboratory procedure.

3. Sulfide monitoring: This method is superior to gas chromatography in that it is
possible to measure total VSC instead of determining individual compounds. An
electrochemical reaction occurs with the sulfur compounds found in the expired air,
which is collected from a tube in the patient's mouth. The halimeter (Interscan
Corporation, Chatsworth CA) is the most recognized device for sulfide monitoring.

Management of halitosis is approached through three primary methods: masking products,
mechanical reduction of micro-organisms and their substances and chemical reduction of
microorganisms (van den Broek, Feenstra et al. 2008). Masking products like mint and
flavored chewing gum has only a short masking effect, lasting less than 3 hours
(Reingewirtz, Girault et al. 1999). Clinical studies examining the mechanical reduction of
microorganisms revealed that brushing the teeth exclusively was not effective in reducing
oral malodor (Yaegaki and Sanada 1992; Kleinberg and Codipilly 2002). With approximately 60%
of VSCs originating on the surface of the tongue, brushing the dorsum of the tongue was
found to be more effective than tooth brushing alone (Yaegaki, Coil et al. 2002).
Furthermore, cleansing the tongue with a tongue scraper showed superior performance when
compared to use of a toothbrush (Pedrazzi, Sato et al. 2004). Based on previous studies, the
dorsum of the tongue has been shown to be an important source of oral malodor (Loesche and
Kazor 2002). Chemical approaches to minimize halitosis include mouth rinses that
specifically reduce the total number of microorganisms in the oral cavity. Chlorhexidine
mouth rinse is the most effective anti-plaque agent on the market today and has been shown
to reduce VSCs by 43% (Rosenberg, Kulkarni et al. 1991; Addy and Moran 1997).

The effect of orthodontic treatment on periodontal health has been investigated in a number
of studies (Zachrisson and Zachrisson 1972; Zachrisson and Alnaes 1974; Atack, Sandy et al.
1996). Inflammation of gingival tissues is observed during orthodontic treatment mainly
because fixed appliances impede adequate oral hygiene measures resulting in an increase in
bacterial plaque accumulation (Ristic, Vlahovic Svabic et al. 2007; Liu, Sun et al. 2011).
Halitosis has been reported to reach critical levels during fixed orthodontic treatment
(Babacan, Sokucu et al. 2011).

Self-ligating brackets do not require an elastic or wire ligature, but have an inbuilt
mechanism that can be opened and closed to secure the orthodontic archwire. In the majority
of designs, this mechanism is a metal face to the bracket slot that is opened and closed
with an instrument (Wenger, Deacon et al. 2008). Conventional brackets typically have
multiple wings and the wire is ligated to the bracket using an elastomeric ring or stainless
steel ties. The effect of self-ligating brackets on oral hygiene has yet to be fully
elucidated. Self-ligating brackets have been reported to accumulate less plaque during
orthodontic treatment when compared to traditional, twin brackets (Pellegrini, Sauerwein et
al. 2009). This may be attributed to retentive area created by the elastomeric rings that
favor the accumulation of microorganisms and food debris. However, other studies have shown
that there is no difference in plaque accumulation between the two bracket types (Pandis,
Vlachopoulos et al. 2008; Garcez, Suzuki et al. 2011).

Objectives

The advantage of self-ligating brackets on periodontal health has yet to be determined. In
addition, the utilization of tongue scraping as an adjunct to traditional oral hygiene
measures has yet to be studied in orthodontic patients. The aim of this study is to evaluate
the effect of bracket type on plaque accumulation and also the impact of the appliance on
oral malodor. In addition, the effect of tongue scraping on halitosis will be studied in
patients undergoing orthodontic treatment.

Aims

The following three aims will be performed to compare the three different appliance systems:

Aim 1: Compare the impact of self-ligating and conventional brackets on oral hygiene,
specifically plaque accumulation.

Aim 2: Determine if an oral hygiene regimen including tongue scraping has an impact on
halitosis in patients undergoing orthodontic treatment.

Aim 3: Determine self-ligating brackets have an impact on minimizing halitosis during
orthodontic treatment.

Hypotheses

Hypothesis 1: Self-ligating brackets will harbor less plaque than normal brackets.

Hypothesis 2: Tongue scraping will significantly decrease halitosis in patients undergoing
orthodontic treatment.

Hypothesis 3: Patients with self-ligating brackets will exhibit less halitosis as measured
by halimeter.

Screening Procedures and Recruitment

Each new patient that comes to the orthodontic clinic at the University of Connecticut
Health center is assigned to a resident or a faculty. So the treating doctor will screen the
new patient to see whether they need orthodontic treatment or not. If the patient requires
orthodontic treatment, the patient has an additional appointment for collecting orthodontic
records to develop the treatment plan. Once the treatment plan is formulated, the patient
returns to discuss the treatment options and to begin the placement of orthodontic
appliances. At this point the patient is ready for appliance placement and the study
coordinator will screen orthodontic patient for possible inclusion in the study by checking
the inclusion criteria discussed later. If the patients were suitable for inclusion, the
study will be described in detail to them, and written information will be given to them.

Statistical Methods

The purpose of this pilot study is to determine the number of patients needed for the
complete study in order to determine statistical significance. Since no previous studies
exist measuring this combination of variables, we need this pilot study to determine the
final sample size for this project and plan to submit a modification of this protocol to the
IRB if we deem it necessary to recruit additional patients.

Inclusion Criteria:

- Fair oral hygiene

- Permanent dentition present with eruption of one or both premolars in each quadrant

- No active carious lesions

- Patients with overall good health

- No previous orthodontic treatment

Exclusion Criteria:

- Previous orthodontic treatment

- Missing or unerupted permanent teeth (both premolars, canines, lateral or central
incisors)

- Extremely poor oral hygiene at baseline

- Existence of active carious lesions (not restored)