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Clinical Section |
Department of Orthodontics and Restorative Dentistry, Glenfield Hospital, Groby Road, Leicester LE3 9QP, UK
Department of Orthodontics, Faculty of Dentistry, Ankara University, Ankara, Turkey
Abstract
Occasionally orthodontic appliances or parts of orthodontic appliances have caused problems with either the airway or the gastrointestinal tract. The type of appliances that have caused problems and their clinical management are discussed. A case is described in which an upper removable appliance with inadequate retention became lodged in a patient's pharynx lacerating the palatine tonsils. Suggestions are made to try and avoid the problems that were encountered in this case and others reported in the literature in patients undergoing orthodontic treatment.
Key words: Airway, Oropharynx, Hazards, Orthodontics removable appliances
Introduction
Incidence of foreign body inhalation or swallowing
Occasionally, orthodontic appliances or parts of them can compromise the airway and gastrointestinal tract due to the close proximity of these appliances to the oropharynx.
The presence of any foreign body in the airway needs to be treated as a serious situation as it can be a cause of accidental death in children (Aytac et al., 1977
). Food materials constitute the majority of foreign bodies found in the airway with the highest incidence being below the age of 3 years (Aytac et al., 1977
; Blazer et al., 1980
). Foreign bodies entering the alimentary canal do not represent such a serious medical problem unless they become impacted or cause perforation of the gut wall as the majority pass through without incidence (Webb et al., 1984
; Hinkle, 1987
; Ghori et al., 1999
).
The incidence of aspiration or swallowing of foreign bodies of dental origin varies considerably in the literature. Tamura et al. (1986) in a review reported the range being 36277 per cent of all foreign bodies, the number being considerably higher in adults than children. The incidence of reported cases of aspiration or ingestion of orthodontic appliances is less common, but no less varied in the types of appliance involved. These include swallowing of a transpalatal arch during its removal (Absi and Buckley, 1995
), a lower spring retainer (Hinkle, 1987
), an upper removable appliance (Martinez et al., 1975
), a fragment of an upper removable appliance (Parkhouse, 1991
), a piece of archwire (Lee, 1992
), and expansion appliance keys (Nazif and Ready, 1983
).
In the delivery of dental care there has been a trend to treat patients in a supine position to aid access to the oral cavity, and improve the comfort of the patient and clinician. In this position there is an increased risk of objects entering the oropharynx (Lanning, 1988
; Cameron et al., 1996
), although it has been suggested that the supine patient is prevented from swallowing, and hence there is less chance of aspiration or swallowing of foreign bodies (Neuhauser, 1975
). However, accidents are possible when treating patients in either position (Jacobi and Shillingburg, 1981
; El Badrawy, 1985
).
Clinical presentation and management
If an object is dropped into the mouth in a supine patient, the patient's head should be turned to one side to encourage the object to fall into the cheek and not the oropharynx (Cameron et al., 1996
) or the patient could be turned face down to allow the object to fall out of the mouth (Barkemeir et al., 1978; Killingback and Stephens, 1988
). The patient should be asked to cough (Jacobi and Shillingburg, 1981
). The mouth and oropharynx should be examined, and if the object is visible it should be removed either with forceps (Jacobi and Shillingburg, 1981
) or high speed suction (Israel and Leban, 1984
), which should be available during all dental procedures (Cameron et al., 1996
). The most readily visible site for entrapment of a foreign body that has become displaced in the oropharynx is the supratonsillar recess, followed by the epiglottic vallecula and the piriform recess. If the foreign body cannot be found in these places it should be assumed that it has either been swallowed or aspirated (Scott and Dooley, 1978
).
The majority of foreign bodies entering the oropharynx will pass into the alimentary canal (Webb et al., 1984
) and pass without incidence, though there is a danger of perforation of the gut which can have very serious consequences including death (Ghori et al., 1999
). In the oesophagus, only large objects and those with sharp edges are liable to become impacted, and if this occurs it is usually at the level of the fourth cervical vertebrae (Hinkle, 1987
). Symptoms of oesophageal obstruction are the inability to swallow, muscle incoordination, pain on swallowing, haematemesis, or vomiting. Once a foreign body has reached the stomach it has an 8090 per cent chance of passing along the gut without problems (Webb et al., 1984
; Hinkle, 1987
; Ghori et al., 1999
). Less than 1 per cent of these foreign bodies have caused a perforation (Gonzalez et al., 1988
; Absi and Buckley, 1995
). The commonest sites for perforation to occur are the ileo-caecal junction and the sigmoid colon. The symptoms vary between abdominal pain, fever, nausea, vomiting, abdominal distension and diagnosis can be difficult (Gonzalez et al., 1988
; Matricardi and Lovati, 1992
; Ghori et al., 1999
). The usual time taken for a foreign body to transverse the intestinal tract is 212 days (Hinkle, 1987
). If it is suspected that a patient has swallowed a foreign body, the patient should be referred to the appropriate medical speciality (Wakeen, 1993
), as it may be necessary to electively remove an object with sharp edges to avoid perforation (Webb et al., 1984
; Ghori et al., 1999
). On occasions, patients have been advised to supplement their diet with a large amount of cellulose, which theoretically will aid the passage of the object through the gut (Neuhauser, 1975
; Absi and Buckley, 1995
). For radiolucent objects, ingestion of cotton wool pellets mixed with small amounts of barium sulphate suspension has been reported to form a radio-opaque bolus around the object, which allows it to be tracked through the gut radiographically (Jacobi and Shillingburg, 1981
).
The aspiration of a foreign body during dental treatment presents a serious problem and the symptoms will depend on where the object becomes impacted. If it gets trapped above the vocal cords, acute respiratory distress can result, which requires urgent action. Smaller objects, however, tend to pass through the vocal cords and upper airway obstruction does not occur (Israel and Leban, 1984
). The commonest symptoms of laryngotracheal foreign bodies are dyspnoea, cough, and stridor, while those of bronchial foreign bodies are cough, decreased air entry, dyspnoea, and wheezing (Blazer et al., 1980
). Hoarseness will accompany obstruction of the larynx or trachea with or without cyanosis depending on whether the obstruction is partial or complete (von Haacke and Wilson, 1986
). Initial symptoms can subside, and small foreign bodies may have no initial effects and go unrecognized until later, when secondary symptoms such as pneumonia develop (Aytac et al., 1977
). Symptoms of inhalation can also be overlooked when the patient has a history of asthma or when the history of inhalation is obscure (Poukkula et al., 1988
). Foreign bodies that have been present for some time can cause abscess formation, pneumonia, atelectasis, or bronchiectasis, and their removal can be complicated by granulation or scar tissue.
Treatment of aspirated foreign bodies is dependent on the severity of the symptoms. If the foreign body is obstructive and the patient is in respiratory distress, dislodgement of the foreign body should be initially attempted with back blows and the Heimlich manoeuvre (Heimlich, 1975
; Jacobi and Shillingbuck, 1981; Lanning, 1988
). If these fail to dislodge the object, positive airway pressure needs to be maintained by artificial respiration and if this fails to maintain a patent airway, the object should be bypassed and an emergency airway established (Edmondson et al., 1989
). The approach recommended is via the cricothyroid membrane and should only be attempted by a medical practitioner with the appropriate training (European Resuscitation Council Guidelines, 1998). Once an airway has been established the patient should be transferred to hospital for emergency medical attention. If the object has passed the vocal cords and there is no obstruction of the airway, the patient should still be referred for immediate medical attention (El Badrawy, 1985
; Hinkle, 1987
). All foreign objects in the respiratory track need removal and this should be done as soon as possible as oedema, excessive secretions and formation of granulation tissue can make localization and removal difficult (Radford et al., 1974
; Israel and Leban, 1984
). The mucosal appearance of the pink acrylic often used in orthodontics can also make visualization during broncoscopy of any fragment of inhaled acrylic difficult and, hence, may complicate its removal (Adelman, 1988
; Ong et al., 1988
). Although spontaneous expectoration of inhaled foreign bodies occurs in 12 per cent of cases (Chatterji and Chatterji, 1972
), waiting for this to happen with postural drainage is no longer recommended as the foreign body dislodged from its original location, may cause obstruction of the airway (Aytac et al., 1977
).
Case Report
A 9-year-old female attended as a new patient to the Dept of Orthodontics, University Dental Hospital, Ankara, with an anterior open bite and a history of digit sucking. She presented with a Class II division 1 malocclusion on a skeletal 1 base, with a 7-mm anterior open bite in the mixed dentition (Figure 1A
). It was thought that the main aetiological factor was the digit sucking, which occurred mainly at night. To eliminate the habit a simple removable appliance was fitted with only osenklammer type retainers (Witt and Gehrke, 1981
; Fischer-Brandies and Stahl, 1990
), which the patient was instructed to wear full time (Figure 1B
).
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She had a history of waking in the night in pain and unable to breath. Her parents were woken by the sound of her in distress, and looking in her mouth they realized that the appliance had become displaced and had lodged in the back of her mouth, compromising the airway. Their initial attempts to remove the appliance were unsuccessful and only after the child was physically restrained by one of her parents, was the other able to remove the appliance. Following the removal there was considerable bleeding from the patient's mouth.
On intra-oral examination a soft tissue injury in the palatine tonsillar region was observed, approximately 3 mm in length and 2 mm in breadth (Figure 1C
). The child was prescribed a course of antibiotics, analgesics, and an antiseptic mouth wash. On review 2 weeks, later healing had occurred and there was no clinical evidence of the laceration.
Discussion
This case report illustrates the ease with which removable appliances can become dislodged if retention is inadequate, and the potentially serious complications to the oropharynx that can arise. Removable appliances are not the only orthodontic appliances that have given rise to problems. Problems have arisen with a variety of appliances, and the following information and recommendations are derived from this case report and those provided by other authors.
The use of a gauze dental napkin as a barrier technique can be very useful when placed behind the orthodontic appliance during its adjustment (Barkemeir et al., 1978).
In some patients, placing molar bands can be difficult, especially second molar bands. To help keep control of bands in these patients and to aid quick retrival, floss can be tied through the tube in a figure-of-eight design (Figure 2A
). Once the band is cemented on the tooth, the floss can be removed. A similar technique has been recommended for the placement of rubber dam clamps (Alexander and Delhom, 1971
; Myers, 1972
; Barkemeir et al., 1978). Auxilliaries that are placed on archwires such as coil springs can be temporarily stabilized on the wire during its placement with wax (Figure 2B
).
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Keys for turning fixed expansion appliances intra-orally should be attached to floss and any open contact on the handle of the key should be soldered to prevent the floss from slipping through the handle (Nazif and Ready, 1983
). An alternative key that is attached to a plastic spatula is now commercially available and may be a preferable alternative (Shilliday Safety Key, Forestadent).
When fitting or removing transpalatal arches and quadhelices, it may be advisable to have a long length of floss tied to the appliance attached via a closed loop on the appliance to avoid its inhalation or swallowing should it be dropped (Absi and Buckley, 1995
; Figure 2C
)
The choice of archwire material and grade should not only be dictated by the forces required to move teeth, but also by the ability of the wire to withstand masticatory stresses (Lee, 1992
). Where there is a large span of unsupported wire consideration should be given to supporting it with tubing.
When cutting the ends of archwires with safety distal end wire cutters, the pliers sometimes fails to hold the cut fragment. A cotton wool roll placed over the end of the archwire before it is cut will prevent the piece of archwire becoming displaced in the mouth, or embedded in the soft tissues of the patient or operator (Killingback and Stephens, 1988
; Perry, 1987
; Figure 2D
).
All orthodontic instruments that are used intra-orally should be regularly inspected for signs of failure, and replaced or reconditioned on a regular basis (Killingback and Stephens, 1988
).
During the taking of impressions the impression material used should have a high viscosity and the tray should be the correct size and fit (Cameron et al., 1996
). An upright position for the patient is recommended with clear instructions to the patient. The clinician should be able to visualize the back of the upper tray as it is seated in the mouth so excess impression material is not allowed to extrude into the back of the mouth. The patient should then be advised to tilt the head forward, place their chin down towards the chest, avoid trying to swallow, and if necessary dribble onto a bib placed on their chest. The patient may find it more comfortable to breath through their mouth, rather than their nose while the impression is seated in the mouth.
If a piece of appliance is dropped in the mouth during treatment, the availability of high speed suction with a pharyngeal tip can help with quick retrieval (Israel and Leban 1984
).
The role of radiography in localization of a foreign body is related to the radiodensity of the object. If the object is radio-opaque or has radio-opaque components, plain film radiographs can be very useful. If the object is radiolucent it will not be visible on plain film radiographs, although secondary changes around the object may be apparent (Poukkula et al., 1988
). Alternative ways of identification and localization of foreign bodies include computerized CT scanning (Newton et al., 1987
; Gonzalez et al., 1988
; Ong et al., 1988
), and barium swallows for objects impacted in the oesophagus (Absi and Buckley, 1995
) and ultrasound (Matricardi and Lovati, 1992
). The use of a radio-opaque acrylic has been recommended extensively in the literature over a considerable period of time for use in dental appliances to aid the detection of acrylic fragments if aspiration or ingestion occurs (McCabe and Wilson, 1976
; Hinkle, 1987
; Newton et al., 1987
; Adelman, 1988
; Knowles, 1991
; Absi and Buckley, 1995
). Most acrylics are radiolucent which makes it difficult to locate the acrylic if it is inhaled or ingested with plane radiography (Perenack, 1980
; von Haacke and Wilson, 1986
; Ong et al 1988
; Poukkula et al, 1988
).
Attempts have been made to produce radio-opaque acrylic for denture construction. These have consisted of incorporation of radio-opaque bodies (lead foil, amalgam), the salts of heavy metals (barium fluoride, barium sulphate, bismuth glass, and barium acrylate) and the production of co-polymers in which one of the co-monomers contains a heavy atom (McCabe and Wilson, 1976
). Unfortunately, the incorporation of these materials into acrylic has adversely affected the properties of the acrylic from the aesthetics to the finish that can be achieve. The incorporation of radio-opaque objects into acrylic tends to set up stress concentrations weakening the material (Chandler et al., 1971a
,b
).
Barium sulphate inclusion has been found to give good radio-opaque appearance on radiographs at 20 per cent, but the physical properties of the resin were found to deteriorate at concentrations above 8 per cent and the control of the colour of the acrylic was adversely affected (Saunsbury, 1964
). Where barium sulphate has been incorporated into denture acrylic, the radio-opacity of the material has aided identification, and its removal in a case of an ingested denture and subsequent perforation of the sigmoid colon (Cleator and Christie, 1973
). Work done on inclusion of bismuth glasses into acrylic, because of the high atomic number of bismuth and its inertness, showed good radio-opacity, but no subsequent work appears to have been carried out (Stafford and MacCulloch, 1971
). A material called Opex appeared in the literature, which appeared to provide good radio-opacity combined with good physical and aesthetic properties, but like the previous material no follow-up investigations or clinical findings have been reported (McCabe and Wilson, 1976
). More recently, work has been published looking at the incorporation of a radio-opaque polymer of methyl methacrylate containing bromine, into denture base materials (Davy and Causton, 1983
). Inclusion of 3640 per cent of the bromine-containing co-polymer was reported to give good radio-opacity, while retaining good mechanical properties.
Recently, glitter-containing acrylics have become available. Some claims have been made that the glitter makes the material radio-opaque on a plane radiograph. To test this claim, six similar simple upper removable appliances were made from six currently available acrylics, five of which incorporated commercially available glitter, one of which the manufacturers claimed was radio-opaque (Leonne, Seato Fiorentino, Italy). A similar appliance was made from a radio-opaque acrylic material which is no longer commercially available (Stellon Radiopaque, Dentsply Ltd; Figure 3
). These appliances were then radiographed in air (46 kV 2 mAs direct exposure, fast screen) and through a phantom abdomen (70 kV 8 mAs, fast screen no grid). The results are shown in Figures 4 and 5![]()
. It can be seen that one (Stellon Radiopaque, Dentsply Ltd) gave a reasonable appearance in air, but none gave good radio-opacity on the abdominal view.
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Conclusions
Acknowledgments
The authors would like to thank Graham Marshall and Grant Catherall for their help with the acquisition of the Stellon material and the construction of the various appliances, and Dr N. Hudson, Consultant Radiologist and Rona Gibson, Senior radiographer, Glenfield Hospital for their help and advice with the radiography. Thanks are also due to Dr Andy Moir, Consultant ENT Surgeon, for his help and advice on aspirated and inhaled foreign bodies in children. Carla Cave for her help with the review of the literature.
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