From Volume 5, Issue 1, January 2012 | Pages 24-28
We present an interesting case of a patient with linear scleroderma of the ‘en coup de sabre’ type who was treated with an upper fixed appliance to align a maxillary canine. It started out as a routine straightforward case of aligning an impacted canine using a conventional technique but developed into a serious orthodontic dilemma.
Linear scleroderma is a type of localized scleroderma characterized by sclerotic skin lesions distributed in a linear, band-like pattern. When linear scleroderma appears on the head it is referred to as linear scleroderma ‘en coup de sabre’ owing to the resemblance of the skin lesions with the stroke of a sword. All localized forms have a 3:1 female predominance, except for linear scleroderma, in which males and females are affected equally. The ‘en coup de sabre’ subtype is estimated to have an incidence of 0.13 per 100,000 population.1
It usually presents in the first or second decade of life as an atrophic-sclerotic band across the frontoparietal area with a varying degree of skin discoloration. The lesion is classically unilateral and does not extend below the eyebrow, although bilateral cases and cases involving the lower face have been described.2
The lesion arises following atrophy of skin, subcutaneous tissue, muscle and occasionally bone. Clinically, it is manifested by ivory-coloured plaques on the frontoparietal scalp and forehead. Lesions may extend to the nose, cheek, chin and neck.2 ‘En coup de sabre’ is more often associated with ocular, oral and neurological abnormalities than other subtypes of linear scleroderma. In one case series, 7 out of 17 patients with craniofacial linear scleroderma were noted to have oral abnormalities: 2 patients had dental abnormalities, a further 3 had malocclusions, and 2 displayed tongue changes.3 Unfortunately, no further details of these abnormalities are given.
Facial hemiatrophy may develop as a result of hypoplasia of the underlying bone and soft tissues. Progressive hemifacial atrophy, Parry-Romberg syndrome, is a related disorder characterized by progressive hemifacial atrophy without cutaneous sclerosis. The relationship between Parry-Romberg syndrome and the ‘en coup de sabre’ subtype of linear morphea has been the subject of debate in the medical literature for over 150 years.4 It is unclear whether Parry-Romberg syndrome and ‘en coup de sabre’ are two separate 5 entities or part of one spectrum.5 Parry-Romberg syndrome classically affects one half of the face, while ‘en coupe de sabre’ presents as a linear streak that is most often located on the paramedian forehead and scalp. Atrophy of the subcutaneous fat represents the primary process in Parry-Romberg syndrome, whereas dermal sclerosis characterizes linear morphea.6 However, areas of morpheoform sclerosis are evident in almost three-quarters of individuals with Parry-Romberg syndrome; one half of Parry-Romberg syndrome patients have co-existent ‘en coup de sabre’ morphea. Conversely one-third of patients with ‘en coupe de sabre’ morphea have co-existent Parry-Romberg syndrome.4
We present an interesting case of an 11-year-old girl who presented to the orthodontic department with an impacted upper right canine in the region of previously diagnosed linear scleroderma of the ‘en coup de sabre’ type which was affecting the soft tissues of the forehead, nose and upper lip predominantly on the right-hand side.
An 11-year-old girl was referred by her general dental practitioner to the orthodontic department. This was for advice regarding crowding. Previous medical history included a diagnosis of linear scleroderma of the ‘en coup de sabre’ type; this diagnosis was made at the age of eight. The scleroderma principally affected the right-hand side of her face, extending from the forehead, down the side of the nose to the lips (Figure 1). She was under the care of a specialist rheumatologist for this condition.
On extra-oral examination, she had a Class I skeletal pattern with average vertical proportions and competent lips. Intra-orally, she was in the late mixed dentition stage. The lower arch was reasonably well aligned with retained deciduous second molars. There was mild crowding in the upper labial segment with canting of the upper occlusal plane in the upper right incisor region. The upper right canine was unerupted and palpable buccally. There was close approximation of the upper right lateral incisor and upper right first premolar. In occlusion, the molar relationship was a full unit II on the right and half II on the left. The overjet measured 4 mm. Radiographic examination revealed a buccally placed impacted upper right canine (Figure 2). All other permanent teeth, including the third molars, were present.
A decision was made to extract the upper right first premolar under local anaesthetic to allow the upper right canine to erupt. Following this, it was decided to fit an upper removable appliance as a space maintainer while the upper right canine erupted. A review appointment was made for nine months' time on the orthodontic recall clinic.
At the nine month orthodontic recall appointment the upper right canine was still unerupted and felt very high on palpation. The patient was asked to carry on with the space maintainer and another review appointment was made for three months' time. At this review appointment the upper right canine was still unerupted (Figure 3). A new orthopantomogram was taken and this showed that there was no improvement in the position of the upper right canine (Figure 4). It was then decided to expose the upper right canine surgically and bond a gold chain to it. Under the same day case general anaesthetic, it was decided to remove the upper left first premolar as well. The procedure was uneventful and the surgical site healed well post-operatively.
Following this procedure, an upper fixed appliance was fitted to align the upper right canine. The upper fixed appliance was fitted 4 months post-operatively and by this time the crown of the upper right canine was just visible. Fixed appliance treatment was commenced with a 0.014″ Nickel Titanium archwire. Two months into treatment with the fixed appliance, the upper right central incisor appeared to discolour significantly (Figure 5a). A periapical radiograph (Figure 5b) of the upper right central incisor was taken and this revealed a periapical radiolucency around the root of this tooth. In view of this unexpected apparent devitalization of the upper right central incisor, it was decided to discontinue orthodontic alignment and remove the fixed appliance. A referral was again made to the oral surgery team for surgical removal of the upper right canine under a day case general anaesthetic. At the same time, the general dental practitioner was asked to carry out endodontic treatment on the upper right central incisor. The extraction was carried out with due care and using an atraumatic technique.
One month post-operatively, the patient developed a dehiscence in the upper right lateral incisor region and the distal surface of the root of this tooth was visible as a result. Maintenance of excellent oral hygiene was advised and a review was arranged for one month. At this review appointment there was no improvement in the dehiscence and the upper right lateral incisor exhibited grade 1 mobility. The dehiscence extended to the middle third of the root of the upper right lateral incisor. In view of these unexpected and unusual complications, it was decided not to carry out any further orthodontic or surgical treatment but to keep the patient under careful review. A review appointment was booked for three months' time.
At this review appointment, the upper right central incisor had spontaneously recovered its normal coloration and appeared clinically vital. The dehiscence around the upper right lateral incisor was still present (Figure 6). All four upper incisors tested positive to ethyl chloride. New radiographs were taken at this appointment which did not reveal any adverse findings (Figure 7). By this time, the patient was about 14 years of age. Advice was sought from the rheumatology specialist who was involved with her care and he advised that the disease was still active and that linear scleroderma usually went into remission towards the end of the growth spurt. It was therefore decided to review the patient regularly at nine-monthly intervals until the disease was in remission. If further orthodontic treatment was desired, this would be carried out at that point with informed consent.
Linear scleroderma ‘en coup de sabre’ is a subtype of localized scleroderma. As with other types of scleroderma, the aetiology of ‘en coup de sabre’ is unknown. Common theories on the aetiology of linear scleroderma ‘en coup de sabre’ are: firstly, that the localized forms of scleroderma are related in the same manner as discoid and systemic lupus erythematosus and thus belong in the collagen-vascular group of diseases with auto-immune phenomena; or, secondly, that localized scleroderma is a developmental disease, occasionally associated with other (predetermined) defects.7 Other theories implicate that viral or bacterial infections (eg B. burgdorferi) and genetic factors may play a role in the aetiology of ‘en coup de sabre’. However, a multifactorial pathogenesis of hemiatrophies is most likely.8 Ophthalmological (eg iridocyclitis, enophthalmus, exophthalmus) and/or neurological (eg intracerebral calcification, hemiplegic headaches, epileptic seizures) manifestations have frequently been observed in patients with ‘en coup de sabre’ and Parry-Romberg syndrome.8
In the present case, band-like scleroderma of the frontoparietal area was observed. These features were consistent with a diagnosis of linear scleroderma ‘en coup de sabre’. In classic progressive facial hemiatrophy or Parry-Romberg syndrome, cutaneous inflammation, induration and adhesion are absent or minimal, and atrophy usually involves one entire side of the face. It has been suggested that the term Parry-Romberg syndrome should only be used for progressive hemifacial atrophy occurring without features of scleroderma. However, a clear differentiation between Parry-Romberg syndrome and linear scleroderma is often not possible, and it is rather an arbitrary approach to differentiate the two diseases because of their extent on the face and more or less sclerosis, despite all their common features observed.9
Although preceding sclerosis was never noticed in many cases of Parry-Romberg syndrome, Jablonska and Blaszczyk observed several patients with typical linear scleroderma in children, converting within several years into facial hemiatrophy.10 Thus the time of investigation is of significance when diagnosing either linear scleroderma and Parry-Romberg syndrome. There are no reliable histological criteria to differentiate Parry-Romberg syndrome from scleroderma. Blaszczyk et al concluded that Parry-Romberg syndrome could be regarded as a variety of deep linear sclerodermas.11
Microchimerism could account for dental and dermatological abnormalities if the tooth was of the same ectodermal origin as the cutaneous tissue affected by the scleroderma.12,13 Histological analysis of linear scleroderma reveals endothelial cell destruction and small artery occlusion by collagen deposition. Such a process could conceivably compromise dental blood supply.
The diagnosis of linear scleroderma ‘en coup de sabre’ is a clinical one. Laboratory abnormalities are minimal in children with both of these disorders. As with other forms of linear scleroderma, some children have positive tests for ANA, but tests for anti-dsDNA, FR, Scl-70, anticentromere antibody, and routine blood tests including CBC and ESR, should be normal. Neurological complications are the most common systemic association with linear scleroderma ‘en coup de sabre’.14 Complex partial seizures have been reported most frequently. Abnormalities on MRI and CT studies may be seen in patients with linear scleroderma, even in the absence of neurological disease.15
Linear scleroderma is usually a self limiting disease. Complete resolution is unusual and re-activation can occur. Patients are at increased risk of long-term morbidity because they may have decreased growth of underlying bones and facial asymmetry.16 If cosmetic disfigurement develops, psychological disability may be pronounced.
Adequate treatment of linear scleroderma remains challenging. Topical, intralesional and systemic corticosteroids reduce the inflammation of skin lesions.17 Systemic agents used when more aggressive therapy is needed include vitamin E, vitamin D3, aminobenzoate potassium, penicillin, retinoids, interferon, immunosuppressive agent and UV-A therapy.18 Orthodontic rehabilitation is often required. Reconstructive surgery may be needed for patients with disfiguring facial atrophy. Subcutaneous injections of polymethylmethacrylate microspheres can be used as part of the treatment for the facial atrophy.19
This unusual case begs the question of whether the asymmetry in the maxillary arch could have been related to the linear scleroderma. The response to orthodontic treatment was undoubtedly most atypical. The temporary devitalization of the upper right central incisor and the consequent dehiscence around the adjacent lateral incisor could certainly have been linked to reduced blood supply in the region of the connective tissue disorder. The dehiscence around the lateral incisor could have developed as a result of the traumatic surgical extraction of the upper right canine. Although it was noted in the surgical report that this procedure was uncomplicated and did require some bone removal, there was no sign of ankylosis of the canine. It seems too much of a coincidence for these complications to develop in the same line as the patient's scleroderma.
A recent case report describes the case of a patient with ‘en coup de sabre’ who, like the case described above, had involvement of the supporting structures around the maxillary central incisor.20 This led to consequent loss of the central incisor. Interestingly, this case also developed gingival recession around the adjacent lateral incisor. Histological analysis of tissue around the central incisor revealed changes consistent with linear scleroderma. However, no orthodontic treatment was undertaken in this case and there was no precipitating cause. In another case report, teeth on the side affected by Parry-Romberg syndrome showed resorption and malformation of the roots, leading to delayed eruption and dental crowding.21
In view of the rarity of the ‘en coup de sabre’ type of linear scleroderma and sparsely reported literature relating to oral and dental abnormalities seen in this disease, we may never know if there is a link between this condition and the orthodontic complications our case developed. We recommend conservative orthodontic management and, where possible, delaying active orthodontic treatment until the disease process is in remission.
