Non-surgical management of a traumatic mid-palatal suture diastasis by novel use of an orthodontic appliance

Diagnosis and aetiology

A 15-year-old male sustained facial injuries following a motorized bike accident. No head and facial helmet protection was worn during the impact. Following a primary survey, head and cervical spinal injury was clinically and radiologically excluded. The primary patient complaint was the development of an upper central incisor diastema and malocclusion following the injury.

Comprehensive facial and intra-oral examination revealed palatal bruising following the course of the mid palatal suture and tendencies towards scissor biting posteriorly on the right side. The patient had a Class 2 intermediate incisor relationship, and there was a 1-mm upper central incisor diastema that the patient said he did not have before (Figure 1). There were no specific traumatic dental injuries with all teeth intact and immobile. The patient had had no previous dental treatment and was medically fit and well with no allergies.

Computed tomography and plain film radiography confirmed a minimally displaced Le Fort II fracture and diastases of the mid-palatal suture (Type III palatal fracture) (Figure 2).

Treatment aims and plan

The primary treatment aims were to reduce and stabilize the palatal fracture to allow appropriate healing and also re-establish occlusion in the correct position. Initial management included analgesia, antiseptic mouthwash, soft diet and maxillary sinus pressure control advice.

A joint orthodontic/oral and maxillofacial surgery multidisciplinary approach was undertaken. Clinical and radiological exam, as well as dental study cast and photographic analysis were used to formulate the definitive treatment plan: conservative management of the Le Fort II fracture, transverse contraction of the maxilla using a ‘reverse’ hyrax appliance and stabilization of the post-treatment occlusion.

A ‘reverse’ hyrax appliance was constructed using the patient's upper dental study model cast. The laboratory technician was instructed to construct a conventional form of the appliance with the key mechanism ‘reversed’. This would allow for the appliance to contract when the key is turned from anterior to posterior. The patient was instructed on how to turn the key mechanism. The bonded RME appliance was fitted by the orthodontic team with anchorage of the upper premolars and molars (Figure 3). It was cemented with a light-cured glass ionomer cement (GC Fuji LC, GC UK Ltd). The key was then turned once (0.2-mm contraction). The patient was then instructed to turn the key twice a day for 2 consecutive days (2 x 0.2 mm x 2 = 0.8-mm contraction), all this with the aim of closing the 1-mm diastema.

Treatment outcome and follow up

On clinical review 7 days later, the diastema had completely closed, with the posterior transverse discrepancy corrected with the scissor bite tendency resolved (Figure 3). His incisor relationship remained as before the accident. The appliance remained in situ for a further 7 weeks to allow stabilization of the occlusion and to splint the palate. A final review was scheduled with both the orthodontic and oral and maxillofacial surgery team at week 8 to assess progress. At this appointment the appliance was removed. The palate had healed and was stable with no remaining diastema (Figure 3).

Discussion

Isolated palatal fractures are not common and are usually associated with concomitant midfacial fractures. Even in these instances, the incidence is low (around 10%).¹² The most common causes of injury are assault and road traffic accidents. Clinical signs suggestive of these fractures include palatal ecchymosis in closed fractures, and lacerations of the upper lip or the palatal mucosa, loss of incisor teeth, occlusal disruption and maxillary tooth diastasis.¹³

René Le Fort (30 March 1869–30 March 1951) reported that fracture lines of the midface tend to travel through the path of least resistance. The palatal suture line is similar to the cranium and forms a strong synostosis during adolescence, with synostosis completion between the ages of 11and 13 years in females and 14 and 16 years in males (although the start and the advance of fusion of the MPS has been reported to vary greatly with age and sex).¹⁴ Thus in pre-adolescent patients any split would tend to be in the midline; however, these fractures are less common in children owing to the elasticity of their facial skeleton, delay in palatal suture synostosis, and the significant amount of force required to fracture the palate.¹⁵ It is this delay in the MPS synostosis that makes management of a traumatic MPS diastasis possible with an orthodontic appliance alone.

Treatment of a palatal fracture is planned and performed with the goal of restoring the transverse width of the palate, the anteroposterior projection of the maxillary arch, and the patient's prior occlusion. Treatment options range from orthodontic appliances, palatal splinting, arch bars for maxillomandibular fixation to internal fixation, with plates and screws placed under the palate mucosa and periosteum, together with alveolar plating.¹⁶ Our patient did not experience a true palatal fracture, but instead a diastasis of the MPS suture. This had not fully fused at the time of the injury, giving it the potential to move quickly and effectively under the correct applied forces. Even so, the treatment aims remain the same as in a true palatal fracture with, in this case, the addition of aesthetic benefit by closure of the diastema between the UL1 and UR1, as well as correction of the posterior transverse malocclusion.

The hyrax is a screw type of appliance that is traditionally used in orthodontic appliances to expand the upper arch. By turning the screw 1–2 times a day, a rapid expansion force can be applied. When the screw is turned 1–2 times a day, the periodontal ligament on the buccal surfaces of the teeth is compressed and lateral force builds up bilaterally in the posterior maxilla. The weakest point in a young patient is the midline suture, and this is split open, causing expansion of the maxilla. In this case, the hyrax screw was mounted in reverse so that turning the screw caused contraction of the upper arch.

A combined orthodontic/oral and maxillofacial surgery multidisciplinary approach helped devise the treatment plan. Knowledge of RME appliances, MPS maturation and morphology were used to create a hyrax appliance that contracted the maxillary arch instead of expanding it. The appliance was designed such that the key was turned in the opposite direction to usual, thus contracting and, therefore, reducing the diastasis. After 1 week of the appliance being in situ, the diastema and posterior scissors bite had been successfully treated. The appliance was left in situ for a total of 7 weeks for stabilization.

Management of these injuries is not well documented due to low incidence. However, in a study carried out in 2015, 13 patients underwent palatal fracture management using a palatal splint made from a rapid light-cure resin, sometimes in conjunction with intermaxillary fixation. It was deemed successful and cost-effective. Other documented treatments involve placing a palatal splint, then physically reducing palatal fractures by applying pressure laterally on the two maxillary halves while applying arch bars; however, there has been no report on the effectiveness of this method.¹⁰ Despite previous use of orthodontic appliances in palatal injuries, no cases of using a ‘reverse RME’ to treat a traumatic MPS diastasis have been recorded.

In this case, allowing healing of the bony segments in their current positions with no intervention was an option⁶. However, this would have left the patient with a residual upper central incisor diastema and occlusal discrepancy, potentially resulting in in the need for future restorative and/or orthodontic treatment. Furthermore, it would have left the patient unhappy in terms of aesthetics. Palatal fractures require rigid horizontal stability of the dentition along with restoration of midface projection and height.⁹ This case demonstrates the possibility to achieve this via non-invasive management. The treatment carried out was reliant on patient compliance; adapting to the intra-oral device, maintenance of oral hygiene and ensuring that correct instructions regarding the key turns was followed. It is also important to carry our regular reviews, and imperative to ensure succinct communication with the lab in construction of the appliance for a successful outcome.

Conclusion

In this case, a novel approach to reduction of a traumatic mid-palatal fracture was successfully employed, using an orthodontic appliance. It is important to think beyond the conventional approach in managing traumatic facial fractures and it is important that treatment planning is approached analytically and flexibly to bring a range of approaches to problem-solving. Current knowledge of well-known clinical practices, combined with a multidisciplinary approach made it possible to create a new and effective way of treating this type of injury.

Learning points