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Cleidocranial dysplasia – the Jerusalem Approach: part 1

Published: September 2013

Bulletin #25 September 2013

Cleidocranial dysplasia – the Jerusalem Approach: part 1

Introduction

Cleidocranial dysplasia (CCD) is an autosomal dominant genetic condition or syndrome which is characterized by short stature, brachycephalic headform, with parietal and frontal bone bossing. The midface is hypoplastic, giving the appearance of mandibular prognathism, although the pattern is usually one of maxillary underdevelopment. The sutures of the skull, particularly the fontanelles, show delayed closure and the presence of numerous centers of ossification leads to the formation of wormian bones, visible on a lateral or antero-posterior cephalogram. The clavicles are deficient to varying degrees and may be totally absent in severe cases, giving the patient a narrow chest and sloping shoulders.

CCD is unlike most other syndromes, insofar as the affected individuals have normal intelligence and some even seem to have a higher level of intelligence than their peers. They do not suffer from physical disability, pain or tendency to infection as the result of their condition and neither do they require treatment of any sort in order to improve their lot. Of course, this is a broad generalization, because each individual patient may show varying degrees of severity of the specific features of the syndrome or may exhibit other symptoms not normally associated with CCD. Thus, one of my patients has bilateral anophthalmia and, while this might occur with any individual, it seems that apparently unrelated other phenomena may be found with greater frequency among CCD patients. This is not an evidence-based statement and merely represents a clinical observation gleaned from the examination of approximately 35-40 affected individuals over the years, as well as from literature reports, in which more than 100 other anomalies have been associated with the above-mentioned major features of CCD.1

Impacted and supernumerary teeth

CCD is perhaps the mother of all conditions in which impacted teeth figure large on the radar screen. In addition to the impaction of the teeth of the normal permanent dentition, the patient usually exhibits unerupted supernumerary teeth, which may number from one or two in one individual and, in rare instances, to as many as 30 in another. 2 Nevertheless, the author has seen cases in which there were no extra teeth and, in one instance, there were congenitally absent maxillary lateral incisors while, in another, a missing third molar!

The dental aspects of the syndrome are usually the most significant features and typically exhibit a severely reduced lower facial height, a concave profile with an edentulous look, over-retained deciduous teeth well into adulthood, relatively few erupted and severely displaced permanent teeth, with very poor occlusion. These patients present with extreme degrees of dental disability.3

In the past and regarding the attitude of dentists to CCD, wholesale extractions were made of the erupted deciduous teeth, the impacted teeth of the normal series and of the supernumerary teeth, with removable and fixed prostheses supported on unerupted or partially erupted abutment teeth. The results were highly unsatisfactory in the long term and, because the oral rehabilitation required is extensive and needs to be performed on relatively young patients, there was the need for repeat and more comprehensive prosthodontics pursuant to further deterioration of the health of the existing natural teeth under these restorations, in the years that followed.

Fortunately, the orthodontic and surgical modality is a modality of treatment which can produce excellent results in these patients, which is in stark contrast to the prognosis of the treatment of the other, non-dental and less debilitating aspects of the condition. Only relatively recently has this modality been considered a viable option for the treatment of CCD and it is capable of yielding superb results. Nevertheless, it requires careful planning and is best divided into several logical stages or phases, each with its own clear goals, aims and direction. 3,4

For the most part, the diagnosis of CCD will have been made by the pediatrician in the first years of an infant’s life. Those with a family history of the condition will obviously be diagnosed earliest, because this fact will have given the parent and doctor advanced warning of this possibility. Among those without a family history, diagnosis may not be made until much later because there are relatively few signs and symptoms that may appear on the surface to indicate abnormality and to recognize the need for a more focused examination. Certainly, the child’s physical development may be slower, his/her stature relatively shorter and the often characteristic facial features relatively unpronounced. But he/she is usually a bright child, a quick learner, with no behavioral problems and is socially well-adjusted – attributes which may tend to obscure even the enquiring mind of the possible existence of a pathologic entity.

So, it is not entirely surprising that, for a small proportion of patients, the diagnosis of CCD may only have been made much later, as the follow-up of a dental examination to investigate the complaint of failure of the deciduous incisors to shed and the permanent incisors to erupt. This will usually occur at approximately 8 years of age, which is when the child is the only one in the class at school who does not have new, large, spaced (and ugly!) anterior teeth. The child is now becoming more and more different from his/her contemporaries because, in infancy what previously were minor differences in stature and facial development, now become aggravated with what must be counted as oral abnormality, insofar as there is none of the expected physical change that should have occurred by this time. The deciduous teeth are likely worn down by attrition, with very short clinical crowns. They are almost completely invisible in normal expression and inter-personal dialogue, giving the child an edentulous appearance and the visage of old age.

This bulletin is planned as the first of a series in which the Jerusalem approach to treatment will be described in its several stages and phases, with full clinical details. In it we shall present an introduction to the very young CCD patient and discuss treatment goals and timing of the first stages in the long haul that will hopefully lead to the establishment of a complete, functioning and attractive dentition. Future bulletins will take the narrative into and beyond the mixed dentition stage, through to the full and natural (i.e. non-prosthodontic) rehabilitation of the oral complex.

Understanding the problem

D_Fig._1

Fig. 1. A misguided flow chart based on false logic leads to harmful conclusions.

Generally, at the age of about 8 years, a parent will seek professional advice. Action may need to be initiated and it is strongly recommended that this be considered after evaluation by a competent and knowledgeable orthodontist. Unfortunately, the child’s first port of call is often another dental professional, whose approach to the problem may well be along the seemingly logical line of thought described in the flow chart (Fig. 1). If this directive is carried out, the child will be dentally maimed for a long period of time – just as long as it takes for the parents and the proactive practitioner to arrive at the realization that the expected improvement has not materialized and, in all probability, will not occur in the foreseeable future. (Where ignorance rules supreme, maiming a child can be achieved despite the best of intentions)

There is no logical basis to assume that this extraction protocol of treatment will succeed because it does not take into consideration 3 important factors which are characteristic of CCD,2 namely:

1. The dental age of a CCD child is approximately 3 years delayed in relation to the chronologic age and that of his/her contemporaries, which means that the permanent incisor successors are too underdeveloped to expect them to erupt.

2. The eruptive potential of the permanent teeth is greatly reduced in CCD and, while some teeth do erupt spontaneously, they take a very long time in coming through and their eruption is rarely complete. Most of the teeth, however, do not erupt at all.

3. CCD patients develop supernumerary teeth, particularly in the incisor region and these constitute physical obstructions that prevent teeth from erupting.

Thus, by extracting teeth alone without the intention of artificially (therapeutically) augmenting the eruptive potential of these teeth, the patient is committed to a very long term edentulous appearance, with no positive outcome in sight. Furthermore, because dental development is so late, it means that active treatment aimed at erupting the front teeth must be delayed until the child’s dental age3 reaches 7 years, which is the time that we would normally want to signs of incisor eruption. In the CCD child, this generally corresponds to the chronologic age of 10 years. To determine this, it is necessary to study the radiographs to look for root development of between ½ and 2/3 of the final expected root length of the incisors. This is the developmental stage of any tooth when the tooth should be erupting into the mouth and it is this stage of tooth development that is seen in recently naturally-erupted teeth in the normal child, unaffected by CCD. Biomechanically erupting a tooth much earlier than this risks damage to the tooth itself and the possibility of reduced root development in the long term.

The first permanent teeth that are scheduled to erupt in any child are the incisors and first molars. These teeth are therefore the teeth that determine the timing of the commencement of orthodontic treatment and, until these teeth have developed 1/2 to 2/3 their final root length, no treatment aimed at encouraging eruption should be performed.

What about the class 3 relationship in CCD patients?

There is a much higher prevalence of a skeletal class 3 jaw relation in CCD patients than in the general population and this is due, in general, to underdevelopment of the maxilla, which causes midface hypoplasia. The class 3 relation is not always evident in the younger CCD individual, but a negative differential growth pattern seems to accelerate at or around puberty. Not all are affected and I have even seen a skeletal class 2 case, which became more severe during subsequent adolescent growth, although this appears to be highly unusual.

In order to treat the skeletal class 3, orthopedic protraction of the maxilla is essential and can be usefully achieved without reference to the state of development of the permanent teeth. Therefore, in the interim and while awaiting adequate root development of the unerupted permanent incisors, protraction of the maxilla can be performed and followed through with the intention of over-correcting the negative overjet and the class 3 dental and skeletal relationships in the full deciduous dentition. While this may often reduce the child’s innate class 3 growth tendency, later growth and a mandibular class 3 dominated pubertal growth spurt or relative growth cessation in the maxilla may still occur, which will undoubtedly indicate the need for later orthosurgical treatment.

For speed and effectiveness, the use of face mask protraction therapy should follow a 24/7 regimen. Wearing the face mask in this manner, an in toto advancement of the maxilla of 5mms on each side can be achieved in about 4 months in children of this age, as recorded in the alteration of the relationship between the upper and lower deciduous molar teeth and in improvement of the deciduous incisor overjet.

What sort of management protocol can be used to achieve this level of compliance?

To influence the patient and the parent to a sufficiently high degree of cooperation is far from easy, but it can be achieved in a good proportion of instances – whether CCD patients or unaffected pure skeletal 3 cases. The most important factor in the equation is to first convince the parent of the efficacy of the appliance and the need for full time wear. If you are able to achieve this, it will generally pay handsome dividends in terms of clinical results. When the parent points out that the child might not be prepared to wear the appliance outside the house, that parent (preferably both parents) is already on your side.

Younger patients are generally less self-conscious of the outlandish appearance of the face mask than are older children. The other children in the kindergarten/pre-school framework and even into the first and second grades of school are aware but less critical than older school peers and do not ridicule or make the child feel uncomfortable. It is also essential to recruit the kindergarten teacher to play a key supportive role in relation to generating a positive attitude of the other children. In this age range, the child spends much time at home and goes to bed early, which makes for the possibility of more wear than in the older child, when full time wear is not completely achievable. Accordingly, there is much to be gained by treating pre-school children, if they are diagnosed sufficiently early. A child can usually be encouraged to wear the appliance if it is simple to place and connect up with elastics to the intra-oral mechanism. Once it is in place, a child can be very receptive to understanding its purpose.

The face mask is possibly the most disliked and improperly used appliance in orthodontics, specifically because of its appearance. Therefore, it is important to make the face mask as unobtrusive and non-restrictive as possible. This presents a problem if one is to use one of the pre-formed face masks that are advertised in the catalogs of the various orthodontic manufacturing companies. Since they are “one-size-fits-all”, they are of necessity very ungainly and clumsy because of the adjustments that need to be made to render them comfortable and effective. In the effort to make the chin and forehead caps comfortable, they are lined with padding, which takes up considerable space. The distance between these two plastic caps varies from patient to patient and so it is necessary to include an adjustable screw fitting. The plastic caps require the placement of a hinge on each to allow adjustability of the angle of the cup to the face. In some designs, there is a thick supporting rod that mimics the midline along the full length of the face to join the chin and forehead caps. Mounted on this are another couple of adjustable screw stops from which the traction elastic will be drawn. In the vain effort to make the appliance “attractive” to the child, the plastic parts are made in bright colors and I have noted that one company links the appliance to a football crash helmet, in the hope that the child will be fooled into believing that he will make the New York Giants team one day!

The alternative is to make the face mask as simple and as inconspicuous as possible, yet strong and comfortable enough to provide the means to the desired end. This demands doing away with the padding in the chin and forehead caps and making them from clear transparent acrylic. It means eliminating adjustable screws to adjust for facial height, doing away with cap hinges, discarding adjustable screw stops and using a narrow wire frame that does not cover the face. What is needed is a custom face mask and it is easy to make using basic dental/orthopedic technology.4,5

Constructing a custom orthodontic/orthopedic face mask

The only ingredients needed in the clinic are as follows:-

1. A broad length of very thin plastic (a.k.a. saran wrap or cling film), usually available from the home store in rolls and intended to cover the salad bowl to prevent the contents from drying out before the guests arrive or, alternatively, a thin plastic bag.

2. A plaster bandage, i.e. a roll of gauze impregnated with plaster of Paris and used in the plaster room of any hospital orthopedic department or office.

3. An indelible pencil or felt-tipped pen.

The patient is seated in the slightly reclined dental chair and his/her clothing protected with a large bib. The thin plastic sheet is carefully wrapped around the head, to completely cover the face – having first cut a hole in it, to be placed over the nose and mouth. It is important to use a large piece of plastic sheeting to fully encircle the head so as to have enough for the ends to overlap each other, thereby to retain it tightly in place. A thin plastic bag may be used, with the hole cut into it as above. The child’s head is positioned in the headrest of the chair, which is now tipped back to almost horizontal. Throughout the procedure, the office should be devoid of all other people, except a parent who is sworn to good behavior. There should be no background disturbances.

D._Fig_2

Fig. 2a, b. A plastic bib covers the patient’s clothing and a thin plastic sheeting (saran wrap or clingfoil) has been secured round the head, with a large hole for unimpeded nasal breathing. The wet plaster bandage has been laid down over the face in a series of circular movements to cover the chin and forehead. A portion of the bandage has been laid over the upper lip. The midline is clearly marked on the plaster.

The roll of plaster bandage is soaked in a bowl of cold water for a few seconds, until it is thoroughly wet. Its free end is placed on the child’s face and it is laid down in a series of wide circles on the plastic, successively over the chin, the face and the forehead as the plaster bandage is rapidly unrolled. This is continued in a round-and-round movement until the outer regions of the face are covered, posteriorly to the ears, superiorly to include the forehead and inferiorly to fully enclose the chin. A narrow strip of plaster bandage should also be taken carefully from one side to the other, across the upper lip, making sure that it does not interfere with the patient’s nasal airway (Fig. 2). The purpose of the several layers around the face is to give the final plaster cast adequate bulk for strength, in the absence of any other form of support. Do not cut the plaster bandage, but continue placing it until the roll is finished.

D_Fig_3

Fig. 3. The separated plaster cast of another patient. Note the chin and forehead cap markings. An outline of the forehead and chin elements, together with a midline, were drawn on the cast before its removal.

The patient is should not be left alone while the plaster is drying, but should be spoken to softly, ensuring that there is no movement to disturb the setting. Before removing the cast, the anatomic midline of the face is drawn on the plaster. The extent of the chincap and forehead cap may also be drawn on, if desired (Fig. 3), although this is easy to define on the casting itself, later on. Once set, the plastic should be carefully freed from behind the head and brought forward on both sides permitting removal of the cast, which should come clear together with its plastic lining. This operation can be performed in a light hearted manner and will be remembered by the child as having been a fun activity – worth photographing. It should be remembered that young children, male or female, have facial hair which is very fine and difficult to see. If this procedure were to be performed directly on the skin of the face, removal of the cast would be very difficult and extremely painful for the patient – it causes me to wince just to think about it!

The plaster cast provides an adequately accurate impression of the face and is sent to the technician who pours it up with the saran plastic wrap still in place, acting as a separating medium. He then constructs a wire frame of 1.5mm wire joining the forehead area with the chin area, taking it posteriorly to just in front of the ears, so that it is not too obvious. He solders a cross piece 5mm labial to the upper lip, with a small soldered hook on each side of the midline. The chin and forehead caps are then fabricated in clear acrylic, into which are cured the ends of the wire frame.

The intra-oral appliance

D_Fig.4

Fig. 4a. Acrylic splint with an expansion screw cured into the acrylic, prior to cementation. Note the buccal hooks in the canine region, in a 9 year old male CCD patient.

Fig. 4b. A similar acrylic splint with transpalatal wire supports, in an 8.5 year old female CCD patient.

Although preformed bands could be cemented to the second deciduous molar, the teeth usually have very short clinical crowns and brackets would need to be placed on the other teeth, together with the construction of a palatal arch. In the present context, it is highly advantageous to use acrylic cap splints on the posterior teeth and a metal skeleton framework to join the two sides. Should expansion be required, a hyrax screw can be substituted as the connector between the two sides, by curing its extension arms into the acrylic covering the teeth (Figs. 4a, b). A wire hook or bondable button, cured into the acrylic on the buccal side in the deciduous canine area, may then be used as the points of application for the elastic traction to the face mask.

The acrylic cap splints should be bonded to the posterior teeth with glass ionomer cement, after sandblasting and/or etching the buccal and lingual surfaces of the teeth as necessary.

Connecting it all up

D_Fig_5

Fig. 5a, b. The face mask in place. Note the minimalist dimensions and the clear acrylic caps and their excellent adaptation to the chin and forehead. Alteration in force direction can be made by bending the crosspiece up or down.

A small elastic is placed on each of the hooks or bonded buttons on the buccal side of the intra-oral appliance and, with the face mask held in place, it is stretched to engage the soldered hooks on the cross piece. With an elastic on each side, the face mask is held against the face quite securely and does not require other forms of retention. The amount of traction force used may be controlled using smaller and/or multiple elastics (Figs. 5, 6, 7).

D_Fig_6

Fig. 6. An occlusal view of the acrylic splint in fig. 4a, showing the traction elastics in place. There are 2 heavy 3/16” elastics on each side

D_Fig_7

Fig. 7. The mouth is opened wide to permit photography of the intra-oral hooks for elastic traction. At rest the direction of traction was tipped slightly downward to the horizontal plane, as seen in fig. 5

The custom face mask requires no padding, since it is an accurate fit on the chin and forehead and, together with the use of clear acrylic and a wire frame far back on the face, it is fairly inconspicuous. There are no knobs, hinges and screws. As the result, the child is much more prepared to wear the appliance and the parent much more positive in encouraging the child to cooperate.

Even with the best bonded cap splints and good oral hygiene, there is always a degree of gingival inflammation and sometimes the appearance of an area of enamel decalcification due to voids created during the cementation procedure. These may not be detected until the cap splints are finally removed. It is therefore essential to complete this pre-eruption phase of the treatment of CCD as quickly and as efficiently as possible, in order to reduce the occurrence of unwanted side-effects and not to drag on the treatment to the time when the eruption phase of the treatment is ready to begin.

References

1. Stewart RE, Prescott GH (eds). Oral Facial Genetics. 1976 Mosby, St Louis.

2. Becker A, Lustmann, Shteyer A. Cleidocranial dysplasia: part 1 - General Principles of the Orthodontic and Surgical Treatment Modality. American Journal of Orthodontics and Dentofacial Orthopedics 111:28-33, 1997.

3. Becker A. Orthodontic Treatment of Impacted Teeth. 3rd edition. Oxford: Wiley-Blackwell Publishers. 2012.

      4. Becker A, Shteyer A, Bimstein E, Lustmann J. Cleidocranial dysplasia: part 2 - a Treatment Protocol for the Orthodontic and Surgical Modality. American Journal of Orthodontics and Dentofacial Orthopedics 111:173-183,1997.

5.        5. Turley PK, Orthopedic correction of Class III Malocclusion with Palatal Expansion and Custom Protraction Headgear. Journal of Clinical Orthodontics 1988;22:314-315.

6.        6. Orton HS, Noar JH, Smith AJ. The Customized Facemask. Journal of Clinical Orthodontics, 1992;26:230-235.