Abstract England. The design was a retrospective clinical audit.


The objective was to assess the timing of referrals of
ectopic maxillary canines, to determine at what age these patients were being
referred and to determine if these referrals comply with the
guidelines by the Royal College of Surgeons of England. The design was a retrospective
clinical audit. Data was collected from clinical notes of patients on the
joint-clinic waiting list in the University Dental Hospital in Cardiff. Data
was collected for 52 patients with canine ectopia on the waiting list during
June 2017. The ‘gold’ standard as stated by Royal College of Surgeons of
England titled Management of the Palatally Ectopic Maxillary Canine published
in 2016 states that all patients with an ectopic canine should be referred by
the age of 12 years. Patients’ data was compared to this standard. Of the 52
patients, 17.3% were referred by the age of 12, meaning 82.7% were referred
late (>12 years). The mean age of referral was 14.9 years of age. It was
concluded that patients are referred late when compared with the guidelines
published by the Royal College of Surgeons.

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Tooth eruption usually occurs by a process in which a forming
tooth migrates from its intraosseous position to a position that allows
function within the oral cavity. (Yaseen, Naik and Uloopi, 2011) An ectopic
tooth can be defined as a tooth that follows an abnormal eruption path whilst
impaction is when a tooth is unable to erupt without interception. This is
commonly associated with an ectopic path of eruption. (Michael, 2011) The
permanent maxillary canine is the most frequent tooth to be impacted with the
exception of the mandibular third molar. The frequency of maxillary canine
impaction varies from 0.8 to 2.8 percent and is more than twice as common in
females. 85 percent of these teeth are found palatally and the remaining 15
percent are found bucally. (McSherry, 1998) 8 percent of canine impactions are
bilateral. The incidence of impaction of the canine is twice as common in the
maxilla as the mandible. (Litsas, 2011)

Generally, causes of delayed eruption can be categorised in
to generalised and localised factors. Generalised causes include irradiation, deficiency
of nutrients, genetic disorders and endocrine diseases. Localised factors are
commonly due to physical obstructions. These obstructions can be supernumerary
teeth or a tumour for example. Mucosal barriers may be an important factor.
Failure of fusion between a developing follicle and the mucosa results in
failure of mucosal breakdown and can prevent eruption. Supernumerary teeth can
cause delayed eruption, displacement and crowding. (Peedikayil, 2011) Tooth
size-arch length discrepancies, early loss or prolonged retention of the
deciduous canine, ankyloses, dilacerations of the root, abnormal tooth-bud
position and idiopathic conditions can lead to ectopic position of the canine,
however, the aetiology is likely to be multifactorial (Bishara and Ortho.,
1992). The maxillary canine has the longest eruption path of all teeth in the
permanent dentition and this may contribute to the aetiology. (McSherry, 1998)

Two theories are commonly used to attempt to explain the
occurrence of palatally ectopic canines. These are the ‘guidance theory’ and
the ‘genetic theory’. Guidance theory proposes that the canine, when erupting,
does not have the guide usually formed by the distal surface of the
neighbouring lateral incisor during the eruption pathway. The lack of guide is
either due to a hypoplastic or missing lateral incisor. This theory is
supported by the fact that in the presence of peg-shaped and missing laterals,
palatally positioned canines are frequently found. (Litsas, 2011) It has been
stated by Brin, Becker and Zilberman, 1993, that there is a direct cause and
effect relationship between missing or peg-shaped lateral incisors and
palatally placed maxillary canines. The alternative theory, genetic theory,
states that the abnormality in eruption of the maxillary canine is as a result
of developmental disturbances of the dental lamina. The variation in frequency between
sexes, bilateral occurrences and familial occurrences may support the idea that
genetics have an important role in canine eruption. Other significant dental
findings such as agenesis of molars and premolars are more commonly found in
those individuals with ectopic canines, also supporting the theory. (Peck, Peck
and Kataja, 1996)

Discrepancies in tooth-arch length are usually responsible
for buccally impacted canines. It was shown in a study that in only 17 percent
of bucally impacted canines there was sufficient space, compared to palatally
impacted canines, where 85 percent of cases had sufficient space for eruption.
(Jacoby, 1983)

There are a number of risks associated with ectopic canines. The
main risk from ectopic canines appears to be root resorption of adjacent teeth,
most commonly the neighbouring lateral incisor. In one study (Walker, Enciso
and Mah, 2005) with use of cone-beam computed tomography, it was found that 66.7
percent of lateral incisors neighbouring an impacted maxillary canines and 11.1
percent of central incisors had some resorption. Other sequelae include
migration of neighbouring teeth, loss of arch length, dentigerous cyst
formation, internal resorption, referred pain, infection especially in those
partially erupted, and a combination of those listed. (Bishara and Ortho.,
1992) On top of these, aesthetics can be a concern for many patients., however,
the presence of an impacted canine may cause no concern or pathology during a
whole lifetime but due to the range of potential risks it is important that the
canines of the developing child should be monitored carefully to detect any abnormalities
and if required, interception of the ectopic canine can then be carried out as
early as possible. 

Patients will very often not be aware that there are any
issues associated with their canines and so therefore general dental
practitioners (GDPs) are in an ideal position to detect an ectopic canine early
and refer appropriately. The Royal College of Surgeons guidelines ‘Management
of the Palatally Ectopic Maxillary Canine’ state that all patients with an
impacted canine should be referred by the age of 12 years. (Husain, Burden and
McSherry, 2016)

All GDPs should, as part of a general examination, palpate
for a canine bulge in patients from the age of 10 years. The British
Orthodontic Society states that a favourable canine is usually palpable by the
age of 10-11. (Managing the developing dentition, 2010) If not palpable, an
ectopic canine should be suspected and a thorough assessment of the malocclusion
should be undertaken, including canine localisation. Radiographic examination
can aid localisation of the canine and the parallax technique can be
particularly useful in assisting in locating the tooth. The retained deciduous
canines should always be assessed for mobility. A firm canine indicates that
the permanent successor has delayed development or there is a failure of
resorption of the deciduous canine by this successor. Mobility, discoloration
or loss of vitality of neighbouring incisors may be due to pressure from an
ectopic canine. The presence of lateral incisor tipping may be due to pressure
placed on the root by an ectopic canine. (Mittal, Murray and Sandler, 2012)

Treatment of an ectopic canine depends on a number of factors
including age and position of the tooth. These treatments range from surgical
exposure and orthodontic alignment to surgical removal of the ectopic canine.
In some cases, the canine can be left and carefully observed. If detected early
enough, in selected cases interceptive extraction of the deciduous canine can
result in an improvement in the position of the ectopic permanent canine. The
patient should be aged between 10 and 13 years. This is a relatively simple,
cost effective method of correcting the malocclusion. (Husain, Burden and
McSherry, 2016) A study by Sune Ericson and Juri Kurol (Ericson and Kurol,
1988) analysed the effect of extraction of the primary canine on palatally
erupting maxillary canines. In this study it was found that 78 percent of the
palatally erupting teeth changed to a normal eruption path after 18 months
although success reduced as the degree of malposition increased. The authors
suggested that in children aged 10-13, extraction of the primary canine is the
treatment of choice to correct palatally ectopic canines provided that there is
sufficient space and no pathology found. They recommended that in later
diagnosis or those with associated pathology, alternative treatment should be
considered. Another study by Power and Short seemed to confirm these findings
but they found a lower success rate of 62 percent. (Power and Short, 1993)
However, two systematic reviews failed to find sufficient evidence to support
this treatment. (Naoumova, Kurol and Kjellberg, 2010;
Parkin et al. 2012) In a Cochrane review, (Parkin, Furness and Shah,
2012) only two studies from an original 324 met the inclusion criteria. The
authors concluded that there are inconsistencies in the data. They state their
concerns about the design and report that neither trial provides evidence that
extraction of the primary canine as an interceptive technique is effective.

 The authors of the
Royal College of Surgeons guidelines suggest that further randomised controlled
trials are recommended to fully assess the effectiveness, although they do
suggest that consideration of this treatment seems reasonable in carefully
selected cases, provided patients/parents are warned that evidence is not conclusive
and further treatment may be required. (Husain, Burden and McSherry, 2016)

Delaying treatment leads to longer, more costly options. A
routinely used technique is surgically exposing the ectopic canine and
attaching a gold change. The gold chain allows the tooth to be brought into the
dental arch and is followed by alignment with the use of fixed orthodontics.
Two techniques are commonly used to expose the ectopic canine. The closed
technique involves exposing the crown of the tooth, etching and bonding the
enamel and attaching a gold chain. The flap is replaced and the gold chain then
hangs from the gingiva. This, after days of healing, has orthodontic traction
applied to it to allow the tooth to gradually move into its correct position
beneath the soft tissues. An alternative technique, the open technique, again
involves exposing the displaced canine, however instead, a window is made in
the tissue covering the tooth, through which the canine is visible. The area is
dressed and this dressing is removed after a few days. The canine can then be
allowed to erupt itself or a gold chain can be attached and orthodontic
traction placed on the tooth. General anaesthetic is commonly used in the UK
for both techniques. The use of local anaesthetic on top of this is still
encouraged to reduce post-operative pain. (Mittal, Murray and Sandler, 2012)
Surgical removal of an ectopic canine may sometimes be indicated if the patient
does not want active treatment or are happy with the appearance of their teeth.
The best results are achieved if the patient is happy to have orthodontic
treatment to reduce the space or if a good contact is present between the
lateral incisor and pre-molar prior to treatment.

Transplantation of the tooth is not commonly carried out. If
the patient is not happy to wear an orthodontic appliance or there is a large
degree of malposition, transplantation can be considered. Sufficient space must
be available and enough alveolar bone must be present to accept the
transplanted canine. The transplanted tooth will often require root canal
treatment depending on the stage of root formation.

If the patient does not want treatment and is happy with
their appearance, the tooth can be left and observed. In order to be left, no
evidence of root resorption or cystic change must be present. If the tooth is
to be left, it must be carefully clinically monitored on a regular basis to
ensure no pathological changes occur.  (Husain,
Burden and McSherry, 2016)

A number of audits looking at the timing of referrals of
ectopic canines have been published from around the United Kingdom. (Hyde,
Barber and Spencer, 2015; Patel and Taylor, 2016) Given the impact of late
referrals on treatment, a referral appropriately timed can reduce the cost and
improve the effectiveness of treatment. It has been found that delays in
referral can remove the chance of straight-forward interceptive extractions and
lead to more complicated, costly treatment. In 2016 an audit was published in
British Dental Journal. This found that 76 percent of patients were referred
late when compared to the Royal College of Surgeons guidelines. (Patel and
Taylor, 2016) A re-audit published in 2015 in the British Orthodontic Society
Clinical Effectiveness Bulletin found that following some interventions such as
delivery of local lectures, alongside an electronic learning package for local
dentists, the percentage of patients referred appropriately regarding an
ectopic canine increased 20 percent from 40 percent to 60 percent. (Hyde,
Barber and Spencer, 2015)




Around the United Kingdom, audits have been carried out
determining whether or not ectopic canines are referred appropriately. However,
no audits looking into the timing of ectopic canine referrals to the University
Dental Hospital in Cardiff have been carried out. By carrying out this audit,
it can be determined whether timing is appropriate when compared with the Royal
College of Surgeons guidelines.  As
discussed previously, late referral reduced the chance of the option of early
interceptive treatment being appropriate, leading to costlier and lengthier
treatment. If it is found that patients are being referred late, interventions
that have previously been successful, such as lectures and electronic learning
packages can be put in place. (Hyde, Barber and Spencer, 2015) A re-audit could
then be carried out at a later date to compare referral times to those found in
this audit and determine whether referral times have improved.

Aims and Objectives

The main aim of the audit was to determine whether current referrals
of patients with ectopic maxillary canines to the University Dental Hospital in
Cardiff are appropriately timed.  Gender
of the referred patients, the position of the canine and associated pathology
were also investigated.


The standard set for the audit was based on the Royal College
of Surgeons of England guidelines on Management of the Palatally Ectopic
Maxillary Canine. All patients with an ectopic maxillary canine should be
referred by the age of 12 years. Data was collected retrospectively. Data was
collected from patients who were on the joint-clinic waiting list June 2017 who
were referred regarding an ectopic maxillary canine. Data was obtained over six
months from their medical records using a standardised collection proforma
which can be found in appendix A. Each set of medical records contained a standard
referral form filled in by the referrer. This included date of referral and
some information about why the patient is being referred. In some cases, a
referral letter was included that explained the findings further. The data
collected included patient age at referral, gender, source of referral,
left/right or bilateral canine, and palatal or buccal position. Once collected,
data was analysed using Microsoft Excel