The hopeless cases?
Hope for the best, prepare for the worst
When it works, it works. But, what is the plan if the teeth do not erupt? If you think of possible failure from the outset, you probably prepare treatment better from the outset. Another saying that works for impacted canines is 'fools rush in, where angels fear to tread'.
The best defense against failure is to do your homework. For the orthodontists this consists in looking at the canine, analyzing its position, anticipating problems form the adjacent teeth and their roots, being aware of complicating factors.
This is an abstract by the head orthodontics and clinic for impacted canines at the Jerusalem
University Hospital, Dr. Stella Chaushu:
Maxillary canine impaction occurs in 1-3% of most Western populations and its orthodontic
treatment is difficult. Failure to resolve the impaction is not uncommon and may lead to
malpractice lawsuits. The information in the literature about the reasons for non-resolution of the
condition is sparse and unsubstantiated. This encourages the dispensing of inappropriate
treatment that may result in severe tooth, soft and hard tissue damage as well as a prolonged
treatment period. This review describes the epidemiology, pathogensis and the wide range of
reasons that may lead to failure to resolve the canine impaction. It shows a lack of appreciation
of anchorage demands and inaccurate positional diagnosis of the 3-D location and orientation of
impacted teeth are the major reasons for failure. In addition the review that invasive cervical
root resorption (ICRR) is a frequently undiagnosed or unrecognized cause of failure of
orthodontic resolution of impacted canines, and should be distinguished from replacement
resorption (ankylosis). Corrective measures which may lead to successful treatment are further
recommended. Special emphasis is placed on the pathology of impacted teeth and damage to
anchor teeth. The importance of teamwork in achieving the best treatment outcome is
stressed.(1)
When it works, it works. But, what is the plan if the teeth do not erupt? If you think of possible failure from the outset, you probably prepare treatment better from the outset. Another saying that works for impacted canines is 'fools rush in, where angels fear to tread'.
The best defense against failure is to do your homework. For the orthodontists this consists in looking at the canine, analyzing its position, anticipating problems form the adjacent teeth and their roots, being aware of complicating factors.
This is an abstract by the head orthodontics and clinic for impacted canines at the Jerusalem
University Hospital, Dr. Stella Chaushu:
Maxillary canine impaction occurs in 1-3% of most Western populations and its orthodontic
treatment is difficult. Failure to resolve the impaction is not uncommon and may lead to
malpractice lawsuits. The information in the literature about the reasons for non-resolution of the
condition is sparse and unsubstantiated. This encourages the dispensing of inappropriate
treatment that may result in severe tooth, soft and hard tissue damage as well as a prolonged
treatment period. This review describes the epidemiology, pathogensis and the wide range of
reasons that may lead to failure to resolve the canine impaction. It shows a lack of appreciation
of anchorage demands and inaccurate positional diagnosis of the 3-D location and orientation of
impacted teeth are the major reasons for failure. In addition the review that invasive cervical
root resorption (ICRR) is a frequently undiagnosed or unrecognized cause of failure of
orthodontic resolution of impacted canines, and should be distinguished from replacement
resorption (ankylosis). Corrective measures which may lead to successful treatment are further
recommended. Special emphasis is placed on the pathology of impacted teeth and damage to
anchor teeth. The importance of teamwork in achieving the best treatment outcome is
stressed.(1)
When the standard procedure does not work, this is the point where your orthodontist has to show his colors. Does he/she:
a) have the experience and inclination to deal with it himself/herself? Does he/she work have a hand-in-glove-working-relationship with an oral surgeon.
b) refer you for 3D imaging and/or to someone specializing in impacted canines (I am not sure if there are anyone, at least they don't advertise), or
c) give up and end the whole thing by referring you to have the canine extracted
a) have the experience and inclination to deal with it himself/herself? Does he/she work have a hand-in-glove-working-relationship with an oral surgeon.
b) refer you for 3D imaging and/or to someone specializing in impacted canines (I am not sure if there are anyone, at least they don't advertise), or
c) give up and end the whole thing by referring you to have the canine extracted
Several articles emphasize that the successful management of a severely impacted maxillary canine require close cooperation of an orthodontist, an oral surgeon, a radiologist, a periodontist, and, if necessary, a prosthodontist. Dr. Adrian Becker writes in his March Bulletin (2) :
The very fact that the tooth has not erupted should raise the suspicions of the orthodontist to find out why.
There is usually an obvious cause. There may be obstruction due to the presence of the root of an adjacent
tooth, or a supernumerary tooth, perhaps an enlarged dental follicle, or conversely, disappearance of the
dental follicle and ankylosis. Most of these factors can be identified ahead of time and should therefore not
come as a surprise, and certainly not after several fruitless years of applying traction – as we sometimes
see.
accurate positional diagnosis is often fraught with difficulty, and mistakes may be made
in locating the tooth - even by experts. As a result, a tooth in an intractable position may be
thought to have a good prognosis, and an inappropriate, ill-advised, and ill-fated course of
treatment will be prescribed.
...
An open surgical exposure of the impacted tooth may close over in the succeeding days and
weeks and make later attachment bonding unreliable or impossible to achieve. When bonding
is performed by the surgeon, as an integral task during an open or closed exposure, an
attachment may be placed in an inappropriate position on the tooth surface or the pigtail ligature
wire or gold chain may have been drawn through the tissues in the wrong direction for traction
to resolve impaction. Alternatively, the bond may fail, and, without further surgery, suitable
conditions for rebonding may be limited or unattainable...(p 261)(18)
These are the possible reasons for failure are, again, in the words of Dr. Becker:
1. Patient-dependent factors (abnormal morphology of the impacted tooth, age, pathology of the impacted
tooth, grossly ectopic tooth, resorption of the root of an adjacent tooth, and lack of compliance
(eg. missed appointments, inadequate oral hygiene).
2. Orthodontist-dependent factors: mistaken positional diagnosis and inappropriate directional force,
missed diagnosis of resorption of the root of an adjacent tooth,, poor anchorage, ineffiecient appliance,
and inadequate torque.
3. Surgeon-dependent factors: mistaken positional diagnosis, exposure of the wrong side, or rummaging
exposure; injury to the an adjacent tooth; soft-tissue damage; and surgery without orthodontic planning.
(p. 743-744). (14)
A factor that significantly influences the duration of treatment but is frequently ignored relates to
the additional period needed to correct deleterious effects created by canine eruption on the
adjacent teeth, ie, loss of anchorage...The anchor teeth must then be realigned, thus increasing
the treatment time...Long periods of orthodontic treatment may lead to damage to the enamel and
the appearance of white spots, decalcified areas, or even caries if good oral hygiene is not
maintained and to more severe root resorption. (pp 235-6)(23)
So, beware of the false ankylosis that only represents failure by the orthodontist to analyze and treat the problem. Even the 'true' ankylosis is a relative term. Teeth that don't respond to traction can be treated, if you happen to live where there are interested specialists, by transplantation and apictomy, see below.
Last recourse (you should hope), extraction!
Pulling out any permanent tooth is not trivial. It is something where your parental knee-jerk reaction is horror, unless it is a wisdom tooth. A canine is a very important part of the dental arch, the corner 'stones'; they have the longest, most massive roots. To lose them is not an easy thing to make up for. This is another quote from Dr. Becker, on the scenario of pulling out a maxillary canine or incisor:
The space may be held open for a future implant which, in a 12-year-old child, may not be for 6
or 8 years. During this time a temporary replacement needs to be made, with all the negative
implications. During this time we will also see a gradually diminishing alveolar bone ridge in this
small edentulous area and the deficiency will be even greater in the months and years after
extraction of the aberrant tooth. When the patient reaches 18 years of age, the implantologist
will be faced with daunting prospect of a severely defective ridge and a questionable prognosis for
the implant.(p 223) (21)
Sadly,it seems there are cases when the best alternative is extraction; the canine is no good for some reason,
it is hurting the surrounding teeth, or it is irreversibly stuck = ankylosed. However, science and research are at work in different parts of the world, so for example the 'dilaceration' quoted below, can be treated in Brasil with
apicotomy or transplantation. In time 'ankylosed' is something that can be overcome.
Extraction indications according to Bishara (16) are:
1. ankylosis and impossible tooth transplantation
2. severe root dilaceration
3. severe retention (lodged between lateral and incisor roots, horizontal placement), in which
surgical uncovering and orthodontic extrusion will hold risks
4. first premolar is in the position of the canine, there is good occlusion and well aligned teeth
5. pathological changes around the tooth (cysts etc.) and the patient is unwilling to be
orthodontically treated (p 121)(17?)
The same article goes on:
Complications related to the extraction of palatally impacted canines are numerous (5):
huge bone defects, damage of adjacent teeth (luxation, comprised parodontium, root fractures)
involvement of maxillary sinus, neuropathies. That is why similar kind of intervention is
usually a last clinical approach to ectopic upper canines. Carried out properly and in close
collaboration with a radiologist, a surgeon, and an orthodontist, it leads to satisfactory results.
(p.121)(17?)
After extraction
If the canine is extracted. There are some options. One is implants. The recommendation has been to wait
for face to be fully grown, as you can measure it by cefalogram. Dr Kokich recommends waiting for boys until they are 21. As I've asked around, this is the opinion of some orthodontist and oral surgeons while there are
some saying that you can put in implants earlier if the cefalograms shows that no growth and change has occured for a year. Leaving a space for several years might make the alveolar bone insufficient for implants unless you put in bne grafts first.
You can try closing the gap by moving over the premolar and the rest of the teeth. This could take 1-2 years more of braces.
Dr Puricelli in Brazil has a method, osteotomy, to cut the bone and approach the teeth to each other and so getting rid of the alveolar defect the extracted canine causes. Her article (5) relates a case of 17-year-old with a dilacerated canine.
Dr Puricelli seems rare in that she, as an oral surgeon, takes a great interest in treating and improving the treatment of impacted canines. It appears, in my personal experience so far, and from the lack of articles by oral surgeons on the subject, that most oral surgeons will do an expose & bond, extraction or implant, but are not especially interested in impacted canines. Add to that, what seems to be a common lack of team work between orthodontists and oral surgeons in the US, and it seems that any advancement of orthodontics and impacted canines will not happen here.
If the canine is extracted. There are some options. One is implants. The recommendation has been to wait
for face to be fully grown, as you can measure it by cefalogram. Dr Kokich recommends waiting for boys until they are 21. As I've asked around, this is the opinion of some orthodontist and oral surgeons while there are
some saying that you can put in implants earlier if the cefalograms shows that no growth and change has occured for a year. Leaving a space for several years might make the alveolar bone insufficient for implants unless you put in bne grafts first.
You can try closing the gap by moving over the premolar and the rest of the teeth. This could take 1-2 years more of braces.
Dr Puricelli in Brazil has a method, osteotomy, to cut the bone and approach the teeth to each other and so getting rid of the alveolar defect the extracted canine causes. Her article (5) relates a case of 17-year-old with a dilacerated canine.
Dr Puricelli seems rare in that she, as an oral surgeon, takes a great interest in treating and improving the treatment of impacted canines. It appears, in my personal experience so far, and from the lack of articles by oral surgeons on the subject, that most oral surgeons will do an expose & bond, extraction or implant, but are not especially interested in impacted canines. Add to that, what seems to be a common lack of team work between orthodontists and oral surgeons in the US, and it seems that any advancement of orthodontics and impacted canines will not happen here.
There must be a way...
I heard an account today on NPR by dentist/plastic surgeon Dr Eduardo D. Rodrigues of NYU Langone Medical Center who recounted how he and his team went about a face transplant. They spent a year just planning, they practiced on 18 (or something) times on cadavers, every part of the surgery. The real surgery was a 36 hour puzzle of transplanting bone, arteries, veins, then nerves, muscles, soft tissue, teeth, skin. It was amazing feat of coordination and determination.
In that perspective, it feels like it should not be that hard erupting a canine! If there was just enough of focused
attention and analysis by dental professionals, and traction by someone skilled enough to understand force, torque, direction, biomechanics etc., those canines would have a better chance.
I heard an account today on NPR by dentist/plastic surgeon Dr Eduardo D. Rodrigues of NYU Langone Medical Center who recounted how he and his team went about a face transplant. They spent a year just planning, they practiced on 18 (or something) times on cadavers, every part of the surgery. The real surgery was a 36 hour puzzle of transplanting bone, arteries, veins, then nerves, muscles, soft tissue, teeth, skin. It was amazing feat of coordination and determination.
In that perspective, it feels like it should not be that hard erupting a canine! If there was just enough of focused
attention and analysis by dental professionals, and traction by someone skilled enough to understand force, torque, direction, biomechanics etc., those canines would have a better chance.
(1) Chaushu S, Abramovitz I, Becker A. Failure in the orthodontic treatment of impacted maxillary canines.
Refuat Hapeh Vehashiinayim, 2013 Apr;30(2): 42-52,81.
(2) Dr Becker March 2113 Bulletin.
(30) http://www.dentist.ie/_fileupload/2009%2055%20No_%205%20-%20Oct%20Nov.pdf
(38) Caminiti et al. Outcomes of the surgical exposure, bonding and eruption of 82 impacted maxillary canines.
Journal of the Canadian Dental Association. Vol 64, issue 8.
(21) Becker, A. Extreme Tooth Impaction and its Resolution. Seminars in Orthodontics, Vol 16, No 3
(September), 2010:pp 223.
(1) Becker A, Chaushu G, Chaushu S. Analysis of failure in the treatment of impacted
canines, Am J Orthod Dentofacial Orthop. 2010 Jun; 137(6): 743-54.
(2) Robert L., Vanarsdall Jr., Efficient Management of Unerupted Teeth: A Time-Tested
Treatment Modality, Seminars in Orthodontics, Vol 16, No 3 (September), 2010:pp
2122-221.
(16) Bishara SE. Clinical management of impacted maxillary canines. Semin Orthod 1998 Jun;4(2):87-98
(5) Edela Puricelli.Partial maxillary apicotomy following an unsuccessful forced eruption of an impacted
maxillary canine. J Appl Oral Sci. 2012 Nov-Dec: 20(6): 667-672.
Refuat Hapeh Vehashiinayim, 2013 Apr;30(2): 42-52,81.
(2) Dr Becker March 2113 Bulletin.
(30) http://www.dentist.ie/_fileupload/2009%2055%20No_%205%20-%20Oct%20Nov.pdf
(38) Caminiti et al. Outcomes of the surgical exposure, bonding and eruption of 82 impacted maxillary canines.
Journal of the Canadian Dental Association. Vol 64, issue 8.
(21) Becker, A. Extreme Tooth Impaction and its Resolution. Seminars in Orthodontics, Vol 16, No 3
(September), 2010:pp 223.
(1) Becker A, Chaushu G, Chaushu S. Analysis of failure in the treatment of impacted
canines, Am J Orthod Dentofacial Orthop. 2010 Jun; 137(6): 743-54.
(2) Robert L., Vanarsdall Jr., Efficient Management of Unerupted Teeth: A Time-Tested
Treatment Modality, Seminars in Orthodontics, Vol 16, No 3 (September), 2010:pp
2122-221.
(16) Bishara SE. Clinical management of impacted maxillary canines. Semin Orthod 1998 Jun;4(2):87-98
(5) Edela Puricelli.Partial maxillary apicotomy following an unsuccessful forced eruption of an impacted
maxillary canine. J Appl Oral Sci. 2012 Nov-Dec: 20(6): 667-672.