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Convincing parents to accept difficult treatment decisions - extractions

Published: October 2015

Bulletin #48 October 2015

Convincing parents to accept difficult treatment decisions - extractions

You have accepted a new patient for an initial pre-treatment consultation and evaluation. You examined the child clinically and have seen only an initial panoramic radiograph. In the discussion that followed, you have given the parents an idea of what is likely to be involved in the treatment and have informed them that the treatment plan will probably involve the extraction of teeth. You have pointed out that sacrificing a tooth/teeth in this particular case will be beneficial to the outcome of the case. In the language of chess, this would be called a gambit. You have also pointed out to them that this is only a tentative opinion, but that a definitive treatment plan would be explained to them after you have seen plaster casts and additional relevant radiographs, which together will enable you to make your diagnosis and definitive treatment plan.

They decide to go ahead and you arrange to obtain the needed casts and radiographs. In your subsequent treatment plan, you decide that several teeth need to be extracted – more than you first thought. Your receptionist calls the parent to make an appointment for you to discuss the plan. The parent asks to speak with you directly, with the view to discussing this in a telephone conversation only, because they live at a considerable distance from the office and it is not easy for them to come. Their real argument is that since you will only be talking and active treatment will not be started at that visit, could you not just provide them with the referral for the extractions. Should you accede to their wishes, you may well spend the next 15 minutes giving them the needed objective criteria on which your decision is based, in the hope that they might understand the finer points that brought you to this decision, in the absence of visual aids of any sort.  The chances are that they will not understand and you then stand a good chance of losing the patient. Assuming your assessment and operative intentions are correct, their decision not to accept your advice can be interpreted as being harmful to the patient. Thus, with the best intentions of both sides, appropriate treatment will have been rejected.

Subjectively, the child does not want teeth to be pulled and neither do the parents. For that matter, you are also in principle against the extraction of healthy teeth. Neither you nor the parents can be sure how the overall experience of extractions will affect the child’s psyche and his/her attitude to dentistry thereafter. So, there is a built-in reticence when it comes to the extraction of healthy teeth, permanent or deciduous. Objectively, however, its performance was necessary to prevent damage and/or to provide benefit. Let us discuss 3 specific cases.

Patient #1

The initial records of the patient were sent to me in October 2012, when she was 9 years of age. The orthodontist in the U.K. requested an opinion because her unerupted maxillary canines appeared to be in locations and at angles which he suspected would not presage normal eruption.  He wondered whether the extraction of deciduous canines might be advantageous in improving the chances. The reason for the referral to me was that the child’s mother, a physician, is my niece and, in her own field, she has a minimum interventionist attitude. She was not at all happy about the possible need to extract teeth.

AAC_Fig._1a_Shiri_Kleinberg_Pan_october_2012

Fig. 1a. A panoramic view of patient #1 and of poor quality, taken at age 9 years. The film shows the mesially displaced and unerupted permanent canines displaced, superimposed on the apical areas of the roots of the lateral incisors.

The quality of the October 2012 panoramic view (Fig. 1a) was poor but it provided sufficient information for me to offer an opinion.  The permanent incisors and first molars were the only erupted permanent teeth in both jaws. I noted that all the permanent teeth could be seen in their various stage of development on the film, including third molars and I assessed her dental age at about 8.5 - 9 years, on the basis of the degree of development of root length and apex closure.1-3 Aside from the right deciduous maxillary first molar which had been extracted due to caries some time earlier, the deciduous molars and canines were all present in the mouth. The unerupted permanent maxillary canines were high up in the maxilla, close to the apices of the lateral incisors and with a mesio-angular orientation, particularly on the right side. The roots of the neighbouring maxillary deciduous canine showed virtually no sign of resorption. At the time I supported the decision to extract the deciduous canines, but I also requested the extraction of the left first deciduous molar, in line with the findings of the study of Alessandri Bonetti et al.4. In my e-mail reply to the orthodontist (with copy to mother) in regard to the right canine, I noted “…. this step should reduce the chances of canine impaction from "highly likely" to just "likely", but I think it is worth the gamble.”

ACA_Fig._1b_intraoral

Fig. 1b. Clinical intraoral views of the teeth in occlusion at age 12.10 years, showing inadequate space for the unerupted maxillary canines.

AAC_Fig._1d_Shiri_2015_annotated

Fig. 1c. The panoramic view at age 12.10 years.The permanent teeth are denoted in blue and the deciduous teeth in red. Note the advanced state of calcification of the roots of all the unerupted permanent teeth compatible with a dental age of about 12 years.

Fast forward to July 2015: I was again called into the decision-making process for my great-niece almost 3 years later and at age 12.10 years. Clinical photographs (Fig. 1b) and the new panoramic film (Fig. 1c) showed that there were still 6 deciduous teeth in the mouth. The left permanent canine had improved its position and direction and appeared likely to erupt normally if space were made for it, but the right canine had not significantly altered its position and must accordingly be re-defined as impacted.

We had clearly lost the gamble of the extraction of the deciduous canines and its hoped-for effect on the right permanent canine!  However, I disagreed with the orthodontist’s expressed view that dental development was delayed, despite the presence of 6 deciduous teeth. I pointed out that the root development of the premolars, canines and lower second molars was well advanced and this would put her dental age at almost the same as her chronologic age. In other words, the deciduous teeth must be re-defined as over-retained and impeding the eruptive progress of the normally-developing premolars. The maxillary first premolars were apparently rotated mesio-buccally and I would not have been surprised to see on a CBCT that the palatal root apex impinged on the unerupted right canine. The lower second molars, with most of the roots completed, were uncharacteristically low down in the bone.

The biggest problem at this time was resolving the impaction of the right maxillary canine. To diagnose its exact position, a cone beam CT was certainly indicated. However, this important diagnostic step was deliberately delayed until the surgical resolution of the dentigerous cyst. The treatment advice given was follows:-

1. place a soldered lower lingual arch and extract the 4 lower deciduous molars

2. place an upper transpalatal bar soldered to molars band, extract the 2 upper deciduous molars and push the first premolars distally to create excess space for the canines. In so doing, I was intentionally  recommending to temporarily crowd out the second premolars. This I advised on the basis that the second premolars will almost always erupt later without a problem when space is re-opened for them.

3. distally upright and mesio-lingually rotate the first premolars to thereby distance the palatal root from the canine and provide the canine with space. This would hopefully encourage the ectopic tooth to start on a downward path.

4. repeat the panoramic radiograph  and, if no positive autonomous progress  was seen, to opt for surgical exposure. It would be at this point and under these circumstances that a CBCT will likely be needed to evaluate the exact location of the canine, whereas I considered it unnecessary until this point.

5. on the same panoramic view, the lower second molars should be reviewed.

Because of the possibility of close proximity of the right canine #13 to the mesially tipped root of the lateral incisor (to be assessed on the CBCT), it would be important not to distally upright this tooth with initial leveling and aligning wires until the canine is distanced - for fear of clashing and resorbing the incisor root. The orthodontist must be aware that a light archwire in a normally-placed edgewise bracket would upright the incisor rapidly and bring it into ill-advised contact with the canine.

So, the alternatives would be:- 

a. not placing a bracket on the lateral incisor until much later, when the later panoramic view evaluation indicated an improved position and distancing of the canine, vis-a-vis the root of the incisor

b. placing a vertically-oriented eyelet and thread the archwire through it - no uprighting possible – and replacing it later with a regular bracket when the canine improves.

c. placing a bracket at an initially abnormal angle that will not upright the tooth - rebonding later

d. placing a Tip Edge bracket, whose very wide beveled slot affords this leeway and later add an auxiliary uprighting spring or re-siting the bracket

Mother and father were copied into this e-mail recommendation and mother’s comment was “….I’m a bit taken aback” and “…. It all sounds rather extensive and invasive” and “…..Surgical exposure of the canine?” and “… How many teeth would need to be extracted?”  and, finally,  “…… we need to speak face to face!” There was obviously a crucial need for a comprehensive explanation.

In preparation for the upcoming discussion, I annotated the panoramic view by labeling the individual teeth on a Power Point presentation, using the easily understandable Federation Dentaire Internationale (FDI) tooth numbering system and this served as an important and graphic visual aid to the explanation. I requested that the parents study it so that we could use this as the basis for a Skype discussion across several thousand miles of cyberspace.

Both parents were highly objective and availed themselves of the opportunity to ask all the important and relevant questions, including the implications of no treatment or alternative treatment. A face-to-face meeting would have been preferable by far but, at the end, they gave their informed consent and accepted the proposed treatment plan.

It is not a comfortable position to be in when long distance advice is sought by parents who are who are family members. However, the orthodontist who had been consulted and who will undertake the treatment, is entirely competent, well qualified and highly respected.

Patient #2 - Just deciduous teeth 

One of the most important principles associated with Serial Extractions, as an orthodontic treatment modality and as first described in 1929 by Kjellgren5 in Sweden, is that extraction of the first deciduous molar at 8-9 years accelerates the eruption of the first premolar, in order that the premolar may be extracted as soon as it erupts and, in any case, well in advance of the eruption of the canine. In crowded cases, the intrabony position of the premolars appears to cause the canine to adopt a more mesial position than is normal. Thus, extraction of the first premolar is a logical step to permitting the canine to autonomously drop back distally into the organizing and repairing premolar socket.

Alessandri Bonetti and co-workers in Bologna, Italy, have recognized that accelerating the eruption of the premolar by extraction of the deciduous molar, at the same time as extracting the deciduous canine offers this advantage even when the premolar is not extracted. The logic is as follows:- as the premolar migrates downward in the maxilla, its crown moves vertically downward and away from the crown of the canine.  The canine then comes into a mesio-distal relationship with the much narrower cervical and root areas of the premolar, which will provide the canine with a little extra space on the distal. In their randomized clinical trial, the Bologna team found that spontaneous eruption of the permanent canine occurred much more frequently than when only the deciduous canine was extracted.

In the mandibular dentition, the difference in time lag between the permanent canine and the first premolar is very small and often the canine will erupt first. Thus, the attempt to accelerate premolar eruption rarely has the same beneficial effect as in the maxilla.

The mother of the child in this second case had been treated by me as a young teenager and had regarded it as a very positive experience, which was why she now brought her daughter to see me. She trusted my judgment implicitly, she had said.

ACA_Fig._2a_R__L__CentreACA_Fig._2b_occlusals

Fig. 2a & 2b. Intra-oral view of the teeth in occlusion and occlusal views of patient #2 showing the marked degree of anterior crowding in both jaws.

ACA Fig. 2c Pan_1

Fig. 2c. The panoramic view on the basis of which it was decided to advise the extraction of the maxillary deciduous canines and deciduous first molars. Extraction of mandibular deciduous teeth was considered non-essential at this time.

The daughter’s dentition (Fig. 2a-c) was in an early mixed dentition stage with antero-posteriorly normally-related teeth in the posterior segments  and the first permanent molars ideally placed. The maxilla was narrow and the deciduous molars were in crossbite on each side. There was a wide median maxillary diastema and the lateral incisors had erupted into lingual crossbite. The central incisors featured a normal overbite and overjet and there was considerable crowding of the incisors in both jaws.

The phase 1 treatment advised was the extraction of the deciduous maxillary canines and first molars only. This was to be followed by correction of the incisor crossbite using a simple removable acrylic plate carrying springs aimed at tipping the lateral incisors over the bite. No treatment was offered in the mandibular arch, although extraction of the deciduous canines might have been expected to achieve some alleviation of the crowding. Further treatment was envisaged in phase 2 for the resolution of the remaining and potential future problems that may occur following the eruption of the premolars and canines.

The treatment plan was kept simple and mother requested being informed in a telephone conversation, since it would otherwise require her to take off time from her important work as a prominent lawyer in the Law Courts. Given the fact that 4 deciduous teeth needed to be extracted, it was felt that there would be a better chance of the parent understanding the reasons for the multiple extractions in a face-to-face meeting. Thus, an appointment was scheduled at the office in order to explain the treatment proposal, using the plaster casts and radiographs as visual aids. I considered that informed consent could only be effectively elicited in this way.

Mother later confirmed that she would not have been prepared to accept this treatment verdict on the basis of the telephone call that she had earlier requested and I would not have been able to provide the child with the full benefit that the plan had to offer. So much for “trusting my judgment implicitly”!

2. Patient #3 - A 4-unit extraction and 5 over-retained deciduous teeth  

This 12 year old girl had been seen by a trained orthodontist and by an oral and maxillofacial surgeon, both of whom felt that the maxillary right canine impaction was particularly difficult and was additionally complicated by a marked degree of generalized crowding. They both considered that the canine should be extracted. The parents were not happy with this advice. Under these circumstances and because of my special interest in the treatment of impacted teeth, the orthodontist decided to refer the case to me for advice and treatment.

ACA Fig. 3a intraoral_1

Fig. 3a. Clinical intra-oral views of the teeth of patient #3. These poorly taken photographs accompanied the patient on her first visit.

ACA Fig. 3a occlusals_3

Fig. 3b. Intra-oral occlusal views of patient #3

.ACA_Fig._3a._Initial_pan_May_2015

Fig. 3c. The panoramic view shows the extreme displacement and horizontal orientation of the canine, with an outline of the dentigerous cyst. It also shows the unresorbed mesial root of the mandibular right deciduous second molar, an enlarged dental follicle at tooth #23 and generally advanced calcification of the unerupted premolars and canines. The mesially impacting second permanent mandibular molars can be seen, together with the congenital absence of 3 of the third molars.

ACA_Fig._3b._May_2015ACA_Fig._3c

Fig. 3d. The lateral skull view shows the maxillary right canine located very high in the maxilla and surrounded by a dentigerous cyst, as can be more clearly seen in the parallel CBCT view.

I examined the patient with the view to evaluating the whole dentition and the overall malocclusion. I then used the existing panoramic radiographic and subsequently performed CBCT images to diagnose the location and relations of the impacted tooth

Much more detailed information is available on the CBCT 3D video clip and on the at the following URL's

https://youtu.be/WAcmIHbLTQ8 Click on this link or paste to your browser to see this video and how it reveals important 3D information of the exact location of the canine in relation to the surrounding teeth and bony structures. Note the enlarged follicle/dentigerous cyst.

https://youtu.be/RkupK7-wX5c Click on this link or paste to your browser to see this video. This multiplanar reconstruction provides serial cuts in one plane, with reference lines to show their exact location in the other 2 planes of space.

Following this, I tried to find a reason why the tooth had become impacted. My findings were as follows:-

Angle’s class 2 division 1 subdivision, with a full class 2 relationship on the right side. The overjet was 8.5mm and the overbite incomplete due to a forward tongue posture during swallowing and speech.

The deciduous canines and deciduous second molars in the maxilla were still present, together with the right mandibular second deciduous molar. A lower dental midline discrepancy of 5mms had resulted in the blocking out of the unerupted, palpable, right canine. This tooth could be palpated high in the vestibulum above the lateral incisor. The teeth in general were large and there was a marked degree of crowding in both jaws. A recent panoramic film was the only radiograph that was initially available and it showed a full complement of permanent teeth, with the exception of the right side third molars. It also confirmed the extreme vertical location and horizontal orientation of the maxillary right canine, high above the reflection of the vestibular mucosa, under the nose and at the level of the anterior nasal spine. The tooth was encompassed by a much enlarged dental follicle/dentigerous cyst. It could also be seen that the adjacent deciduous canine had an almost complete root, exhibiting no resorption. The mandibular permanent second molars were unerupted and mesially tipped, mildly impacting against the distal bulge of the first permanent molars.

Given the child’s mild bimaxillary protrusion, together with the crowding of her large teeth anteriorly and posteriorly, she was clearly a candidate for a 4 unit extraction procedure – but which 4 and what about the 5 retained deciduous teeth?

With the class 2 relation and the enlarged overjet, the natural choice for mandibular extraction was the second premolar on the right side. On left side, the first premolar was chosen to enable a swift resolution of the midline discrepancy.

The difficult decision came in regard to the right side of the maxilla. If the first premolar were to be sacrificed on the right side, we would then need to deal with a large cystic lesion and a very difficult canine impaction, both in terms of the biomechanics and the post-treatment periodontal prognosis. There was no question that the chances of a technically successful reduction of the impaction and ideal orthodontic alignment were very high, with a good degree of spontaneous positional improvement likely, following the elimination of the cyst. However, the projected outcome would leave the patient with a canine which had increased crown length and the strong possibility of an oral mucosa attachment on the labial side, rather than attached gingiva.

The temptation to plan to realign the canine at the expense of the first premolar might be considered by some orthodontists to be one of the signs of their “passage to manhood”. The fact that another orthodontist and an oral and maxillofacial surgeon had recommended the opposite might be further encouragement for him (not usually her) to go for it. This is likely to be more for the orthodontist’s macho prowess than for the patient’s benefit.

The 5 deciduous teeth were still in place because the two maxillary second premolars were mildly lingually inclined and the mandibular second premolar was resorbing only the distal root of the deciduous molar. Dental crowding had slowed down the eruption of the left canine, leaving the deciduous canine relatively undisturbed and its antimere was similarly unaffected because of the displaced right permanent canine in question. Each of the successor permanent teeth had more than 2/3 of their final root length, which therefore determined that the 5 deciduous teeth were over-retained.

Appliance therapy should be initiated in the mandibular dentition immediately following the extractions, to move the dental midline to the left and to create space for the spontaneous eruption of the right canine.

In the maxilla and assuming that the choice for extraction on the right side would be the canine itself, then appliance therapy would begin immediately and among its other functions, it would be aimed at relocating the first premolar into the canine site. If the preference of the orthodontist would be to extract the premolar, then exposure of the canine should not be undertaken at least until several months have elapsed following the extractions, in order to permit the patient to benefit from a potentially considerable degree of spontaneous reduction of the displacement of the canine that is likely to occur with elimination of the dentigerous cyst. In this case, a maxillary holding device would be needed to prevent molar drifting and space loss.

It is at this point that I was in a position to speak with the parents and child, to deliver the verdict that 4 permanent and 5 deciduous teeth need to be extracted as an intrinsic part of the orthodontic treatment! This type of consultation session could last anything from 15 to 45 minutes of my valuable time, depending on the parents’ level of understanding and sophistication and on my mode of presentation of the facts and the plans for treatment. Visual aids were essential and began with the plaster casts, the panoramic film and an annotated tracing of the film. These were then followed up with a few 3D screen shots and a 3D video clip movie to enhance the parents’ and child’s understanding.

The preparation for the meeting was time-consuming, but successfully achieved its intended outcome and the patient was referred to have her 9 teeth extracted as the first step in her treatment.

References

1.   Nolla CM. The development of permanent teeth. J Dent Child 1960; 27: 254–66.

2. Demerjian A, Goldstein H, Tanner JM. A new system of dental age assessment. Hum Biol 1973; 45: 211–27.

3. Becker A. Orthodontic Treatment of Impacted Teeth. 3rd edition, 2012. Oxford: Wiley-Blackwell Publishers. 2012. ISBN-13:978-1-4443-3675-7,   ISBN-10:1-4443-3675-4.

4.   Alessandri Bonetti G, Zanarini M, Parenti SC, Marini I, Gatto MR. Preventive treatment of ectopically erupting maxillary permanent canines by extraction of deciduous canines and first molars: A randomized clinical trial. AmJ Orthod Dentofac Orthop, 2011, 139:316-323.

5. Kjellgren, B. Serial extraction as a corrective procedure in dental orthopedic therapy. Acta Odontol Scand, 1948;8:17–43.