Sequelae of Primary Dental Trauma: A Case Series

Trauma to the primary dentition is a common occurrence affecting approximately 1 in 5 young children globally.¹ In addition to the initial physical injury to the child, the unerupted, developing permanent dentition may also be impacted to varying degrees of severity. This case series describes the sequelae of primary trauma, its diagnosis and management, therefore enabling delivery of advice and expectation management for paediatric patients and their families.

Damage to the developing permanent dentition following primary dental trauma is uncommon, but arises owing to the close proximity of the primary tooth apex to its successor's developing tooth germ (Table 1). The severity of the developmental disturbance to the permanent tooth reflects the type of trauma sustained, the force of impact, and the child's age and stage of dental development. Mild luxation, extrusion or crown fracture injuries to the primary tooth may result in white-yellow or brown enamel discolouration and hypoplasia of the permanent successor, while severe dental trauma such as avulsion, intrusion and alveolar trauma are likely to be associated with more significant dental abnormality including crown or root dilaceration, sequestration of successor tooth germs and disturbances in eruption.²

The acute management of primary dental trauma often requires long-term active monitoring and assessment of indicators of treatment need. As primary and secondary teeth are often separated by only a few millimetres of fibrous connective tissue, the extraction of a traumatized primary tooth has the potential to further traumatize its successor. Intrusive luxation is considered the most damaging primary dental injury, hence current dental trauma guidelines recommend intervention only when signs of pulpal necrosis are evident.⁵ This is due to evidence that intruded primary teeth have a tendency to spontaneously re-erupt, and also due to a lack of evidence that their immediate extraction minimizes further damage to the successor tooth germ. In clinical practice, intervention for primary trauma is indicated in only a minority of patients. Holan demonstrated that only 25% of traumatized primary teeth devitalized (developed an associated sinus or swelling) within a 5-year follow up.⁶

It is recommended that children with primary trauma are reviewed until the eruption of the successor secondary tooth.⁵ Crown formation of the permanent incisors begins at age 7 months and continues to 5 years. Incidence of dental trauma is increased during this age range, and is linked with poor muscle coordination of young children learning to walk and play (Table 2). Therefore, dental trauma within this age range carries an increased risk and complexity of damage to the permanent incisors.

General dental practitioners (GDPs) are often the first to identify and diagnose complications arising from primary dental trauma. Earlier primary dental trauma can often be forgotten by parents and it is not until an anomalous permanent successor erupts, or the eruption of the permanent tooth is delayed or fails, that complications from the primary trauma are recognized. Following dental trauma, parental involvement in monitoring their child's teeth is essential and it is the role of the dentist to educate parents to prioritize regular trauma follow up. Delivering appropriate advice to the affected families is essential in ensuring trauma review attendance, identification of pulpal necrosis symptoms and prevention of repeat trauma. For instance, increased overjet, and associated digit sucking habits, are high risk of trauma to primary and permanent maxillary incisors, thus cessation advice is recommended as part of management in general dental care.^8,9,10

The majority of enamel defects affecting permanent incisors that develop as a consequence of trauma to the preceding primary dentition can be managed in general dental practice. This would most frequently involve restoration of enamel hypoplasia as part of level 1 care.¹¹ In that regard, specialist management of complications in the permanent dentition following primary trauma may be indicated as part of level 3 care for multidisciplinary input, or for management of dental development abnormalities not amenable to simple preventive or restorative treatment.¹¹ Therefore timely referral to their local hospital orthodontic or paediatric dentistry department is essential in optimising patient outcomes.

The following case reports showcase four paediatric patients who presented with a range of anomalies in their permanent dentition following primary dental trauma. Their referral to secondary care and subsequent management is described in order to inform the reader about what can be expected after such a referral is made, so that this information can be shared with patients and their families. Features such as a history of severe primary dental trauma, multiple complex developmental anomalies of the permanent dentition and the burden of completing and maintaining dental treatment into adulthood are common to all the patients described, and are shared themes in patients with this history.¹² Clinicians may find parents are unable to report on the type of primary trauma their child experienced many years ago. Hence as part of history taking, the clinician can ask if the nature of the injury resulted in movement of the tooth or a break in the tooth to determine whether it was a luxative or fracture injury, and therefore gain insight on its likely long-term prognosis. For each case, the authors provide learning points that can be applied by clinicians working in both primary and secondary care settings.

Case 1: Enamel hypoplasia

Enamel defects can occur following disruption to amelogenesis in the late secretory or early maturation phase of dental development. Trauma to the tooth germ during this window of development can result in defects in the enamel, such as hypoplasia or hypomineralization. Enamel hypoplasia is a defect in the quantity of enamel, presenting as white-yellow-brown discolouration and sensitivity, and radiographically as transverse radiolucent lines. This is distinguished from hypomineralization, which is a defect in the enamel quality resulting in discolouration, sensitivity, reduced bonding strength to resin restorations and radiographic presentation of blurred enamel and dentine radiodensities (Figure 2). ^13,14

Enamel hypoplasia is one of the most common sequelae of primary dental trauma, affecting 12–23% of permanent teeth,^2,3 and most likely to be the result of mild injury to the developing tooth germ during late secretory stage of amelogenesis.¹⁵ Patients with enamel defects on their anterior teeth often have functional complaints of pain and sensitivity, as well as aesthetic concerns, which may be accompanied by psychosocial and bullying issues.¹²

An 11-year-old girl was referred by her GDP to the paediatric dental department with concerns of sensitivity on cold stimuli and self-esteem issues associated with her upper front teeth. Her parent recalled a history of dental trauma when she was 12 months old at home; however, no further specific detail around the exact trauma diagnosis was provided. She was otherwise medically fit and well.

Following clinical and radiographic assessment (Figure 3) the below diagnoses were made:

• UR2, UR1 and UL1: severe enamel hypoplasia;
• UR1: dilaceration of crown;
• UR2, UR1 and UL1: vital on sensibility testing with no signs of pathology;
• LL6, LLE, LRE and LR6: caries;
• High caries risk;
• Generalized gingivitis;
• Incisor malocclusion: Class II division 1 with reduced overbite;
• Mixed dentition;
• Compliant for chairside dental treatment under local anaesthesia.

Although it was recognized that this patient could have been managed in primary care alone, a treatment plan for shared care was adopted owing to the concerns expressed in the referral about managing a potentially anxious child with severe enamel defects. This plan included:

• Caries prevention: effective twice daily oral hygiene, reduced frequency and amount of dietary sugars and acids, fluoride adjuncts, including prescription of 2800ppm fluoride toothpaste, regular fluoride varnish application and fissure sealant of non-carious first permanent molars (UR6 and UL6).
• Caries management in primary care: extraction of LLE and LRE and restoration of LL6 and LR6.
• Restoration of hypoplastic and dilacerated teeth in secondary care: composite build up under local anaesthesia and dry dam of UR2, UR1 and UL1 (Figure 4).
• Multidisciplinary team (MDT) assessment for long-term treatment planning of UR1, which had a guarded prognosis, with management of expectations of attendance for long-term maintenance of treatment. Initially this was likely to involve monitoring of UR1 in primary care. If it became non-vital, it was to be planned for subsequent extraction and prosthetic replacement, in either primary or secondary care. Orthodontic treatment with fixed appliances may be required to idealize spacing for the replacement UR1.

Learning points

Stabilization and prevention of active pathology

A hypoplastic enamel surface places the patient at increased caries risk. For any patient, but particularly those with complex treatment needs, active caries and periodontal disease require stabilization, ideally prior to the restorative treatment phase, because this will reduce gingival bleeding and risk of secondary caries and thus improve aesthetics and longer-term outcome. Emphasizing the importance of excellent oral hygiene and a non-cariogenic diet, and placement of fissure sealants in patients with increased caries risk is key in delivering successful, long-lasting restorative care.

Anxiety management

Hypoplastic teeth are often hypersensitive and can be painful during non-invasive procedures, including composite bonding, so the use of local anaesthetic can help ensure patient comfort and build trust and confidence in the treating dentist. Adopting behavioural management techniques such as ‘tell, show, do’, and distraction is recognized as beneficial in earning cooperation in the paediatric patient.¹⁶

Adhesive bonding

Effective moisture control is vital in ensuring successful adhesion to resin composite restorations. The use of retraction cord for subgingival margins and dry dam or rubber dam with clamp to completely expose the defect should be considered. (Figure 5) Hypomineralized defects may also present in isolation, or in conjunction with hypoplasia, so deproteinization using sodium hypochlorite (5.25%) for 60 seconds post-etch can be used to increase the surface area for improved adhesion.¹⁷

Case 2: Dilaceration

Dilaceration is the abrupt structural deviation or angulation of the long-axis crown or root of a tooth, due to traumatic non-axial displacement of the hard tissue tooth germ.¹⁵ Up to 3% of permanent teeth are dilacerated due to trauma to their predecessors.³ Dilaceration of the crown presents more frequently than root dilaceration because it is the crown of the permanent incisor that is developing between the ages of 1 and 4 years when primary dental trauma is more frequently sustained.^15,18 Depending on the site of dilaceration and the degree of resultant abnormality in morphology, eruption may be delayed or fail, resulting in a partially or completely unerupted tooth.¹⁵

A fit and well 7-year-old boy was referred by his GDP due to concerns regarding the palatal position of his erupting UR1. He had previously attended our paediatric dental department aged 20 months when he experienced severe intrusion of URA and avulsion of ULA. Following clinical and radiographic examination (Figure 6), the following diagnoses were made:

• UR1: severe dilaceration (crown and root) and enamel hypoplasia; poor prognosis;
• UR2: unerupted and impacted against dilacerated UR1;
• UL1: unerupted and rotated;
• Incisal malocclusion: Class III malocclusion;
• Chronic gingivitis;
• Mixed dentition;
• Good compliance for dental treatment.

During subsequent treatment, the following diagnoses were also noted and managed:

• LLE and LRE: moderate infra-occlusion/submerged (Figure 7);
• Persistent chronic gingivitis;
• UR1: severe dilaceration ‘S-shaped’; poor prognosis (Figure 8).

This patient was assessed and treatment-planned in the MDT clinic for treatment that would be carried out in phases:

• Caries prevention: effective twice daily oral hygiene, reduced frequency and amount of dietary sugars and acids, 1450ppm fluoride toothpaste and regular review in primary care.
• Aid eruption of impacted and unerupted UR2, UR1, UL1 and UL2: interceptive upper removal appliance to ‘nudge’ UR1 into a more labial position, and extraction of URC and ULC under inhalation sedation and local anaesthesia (Figure 9a).
• Provisional maintenance of UR1: composite restoration (Figure 7 and 9b).
• Evaluation of prognosis of UR1: CBCT scan revealed it was ‘S-shaped’ and would not be ideal to maintain alongside orthodontic therapy (Figure 8).
• Orthodontic therapy: upper and lower fixed appliance to correct malocclusion and prepare movement of UR2 into maxillary central incisor space.
• Definitive management of poor prognosis UR1, orthodontic extraction for severe upper arch crowding and removal of retained upper and moderately infra-occluded mandibular primary second molars: extraction of URE, UR1, UL4, ULE, LLE and LRE under general anaesthesia (GA) (Figure 9c).
• Review of dental development: identification of crowding in developed permanent arch requiring orthodontic extraction
• Orthodontic extraction in primary care: extraction of LL5 and LR5 under local anaesthesia.
• Masking UR2 as maxillary central incisor: composite build-up of UR2, completed during orthodontic fixed appliance therapy to move UR2 into the maxillary central incisor space (Figure 9d).
• Improvement of UR2 upon completion of orthodontic therapy: polishing of composite restoration and gingivectomy (Figure 9e).

Learning points

Phased treatment

As dilacerated teeth often remain impacted and unerupted, it can be difficult to accurately predict the success of bringing them into alignment. Phased treatment planning may provide the opportunity to provide relatively simple, interim interventions aimed at addressing ongoing patient concerns in a developing patient, while allowing a more complete, later assessment of restorability and long-term prognosis as part of definitive treatment planning. Keeping patients and their parents informed of this approach from the outset is important in managing their expectations and promoting compliance in attendance.

Assessment of prognosis

The use of CBCT is helpful to assess prognosis of unerupted dilacerated teeth. Planned extraction of a poor prognosis permanent tooth during active dental development can improve the overall prognosis of their adult dentition alongside orthodontic and restorative management.

Multidisciplinary treatment planning

The benefit of a joint specialty interface in secondary care has been highlighted throughout this case. Joint clinic input from the start of his journey has ensured effective communication and good team working to complete each treatment phase and appropriately manage patient and parent expectations. For instance, it enabled our teams to address and manage the patient's concern about a ‘small front tooth’ (UR2) and the infra-occluding mandibular primary molars in a timely manner.

Case 3: Dentigerous cysts

Dentigerous cysts are benign inflammatory odontogenic lesions attached to an unerupted tooth's cervical region, enveloping its crown.¹⁹ The majority of dentigerous cysts are developmental, forming due to alteration of reduced enamel epithelium, resulting in fluid accumulation between the epithelium and crown.²⁰ In rare cases, dentigerous cysts may form around developing permanent teeth in response to chronic peri-apical inflammation from overlying necrotic primary teeth, resulting in inflammatory exudate accumulation between the reduced enamel epithelium and enamel layers.^20,21,22 The presence of such a dentigerous cyst then obstructs the eruption of the permanent tooth, resulting in its ectopic position. Although some evidence suggests dentigerous cysts can disrupt amelogenesis resulting in hypoplasia,²³ the presence of additional dental anomalies (enamel hypoplasia and dilaceration for example) are more likely to be the result of the original primary dental trauma rather than subsequent cyst development.

A 10-year-old girl was referred to the orthodontic department with the complaint of an unerupted UL1. She was medically fit and well, but reported a persisting thumb-sucking habit. Her parent reported a history of dental trauma to ULA aged 3 years, the family understood that this tooth had been lost (avulsed) at this time. Plain film radiographs (Figure 10) and CBCT imaging revealed that UL1 was present, but dilacerated and horizontally positioned. A sizeable dentigerous cyst was noted to be associated with its crown. CBCT revealed that the primary central incisor (ULA) was retained and lying superior to the permanent incisor root, in a position closely related to the floor of the nose.

Following clinical and radiographic examinations, the following diagnoses were made:

• UL1: severe root dilaceration, enamel hypoplasia, horizontal ectopic position and associated dentigerous cyst;
• ULA: severe intrusion (submerged and non-vital following earlier trauma);
• UR2: diminutive and potentially transposed with upper left maxillary canine;
• Chronic gingivitis;
• Incisal malocclusion: Class I malocclusion with crowding;
• Mixed dentition;
• Good compliance for dental treatment.

Prompt assessment and treatment planning following referral to our MDT optimised the outcome for this patient following delayed presentation:

• Prevention of caries and exacerbation of malocclusion: effective twice daily oral hygiene, reduced frequency and amount of dietary sugars and acids, 1450ppm fluoride toothpaste, regular review in primary care and immediate cessation of digit-sucking habit (Figure 11a).
• Removal of pathology: surgical removal of submerged ULA and enucleation of dentigerous cyst associated with crown of UL1 under GA.
• Space maintenance of UL1 space: construction of upper removable partial denture to prevent space loss in the maxillary central incisor region while monitoring UL1 eruption.
• MDT review of developing dentition 9 months post-cyst enucleation: a repeat CBCT (Figure 12) was taken to assess prognosis of UL1. No improvement in its position was noted following surgical intervention and it was declared poor prognosis.
• Definitive management of poor prognosis UL1, ectopic UL3 and orthodontic extractions: surgical removal of UL1, exposure and bonding of gold chain to UL3 and extraction of URE, UR4, ULC, ULE, LL5, LLE, LRE and LR5 under GA (Figure 11b).
• Orthodontic therapy: upper and lower fixed appliances to correct malocclusion, prepare movement of UL2 into maxillary central incisor space and align the ectopic UL3 (Figure 11c).
• Masking UL2 as the maxillary central incisor and UL3 as the adjacent lateral incisor: composite build-up of UL2, completed during orthodontic fixed appliance therapy.
• Polishing of composite restorations at time of orthodontic bracket debonding and long-term retention with vacuum-formed retainers (Figure 11d).

Learning points

Primary dental trauma management

All patients who have experienced primary dental trauma should be regularly reviewed as part of dental trauma guidelines.⁵ It is important to account for suspected avulsed teeth at the time of injury and radiographic assessment can be used to identify whether traumatized teeth have truly been avulsed or if, in fact, they are retained and intruded. Engaging parents and ensuring that they appreciate the need for regular, long-term follow up of their child's dentition at the time they present with primary dental trauma is essential. A description of the possible sequelae to the permanent dentition is imperative to avoid their loss to follow up and associated late presentation for future treatment needs. A clear, but empathetic, discussion at this stage prevents lack of parental education and prioritization being a barrier to their child accessing the dental care that they require later.

Timely referral

Regular monitoring and the identification of an unerupted tooth is needed to ensure timely referral for specialist care. The Royal College of Surgeons guideline defines an unerupted maxillary incisor as the absence of eruption of the incisor more than 6 months after the eruption of the contralateral incisor, or more than 1 year following the eruption of the mandibular incisors.²⁴ Early diagnosis and appropriate management, often consisting of MDT input is recommended.

Dentigerous cyst management

The overarching aim of dentigerous cyst enucleation is to remove cystic epithelium and allow bony infill of the remaining cavity. A conservative approach is often taken to allow this process to occur. Following bony infill and healing, a second GA episode may be planned due to complications involving the associated unerupted tooth. It is important to discuss with the patient and family the possible need for repeat GA and risk of lack of eruption as a consequence of dilaceration and/or additional ankylosis.

Case 4: Nasal complications

Maxillary sinus mucocele is an uncommon (3–10%),²⁵ cyst of the paranasal epithelial lining that develops as a consequence of the obstruction of the maxillary sinus ostium and subsequent mucus accumulation. This phenomenon is reported to result from the presence of chronic sinusitis, polyps, tumours and trauma.^26,27 Slow-growing maxillary sinus mucocele development following facial fracture has been reported,^28,29 although there has not been any reported cases of mucocele development following dental trauma.

An 8-year-old boy presented to the paediatric dental department complaining of a retained maxillary primary incisor and unerupted permanent central incisor. He had a history of trauma to his primary incisor aged 4 years. The family had been informed by his GDP that UL1 may be dilacerated as a consequence of the earlier trauma and that this tooth may require surgical intervention. At his first consultation the patient's mother revealed her concerns about his recurrent nosebleeds; his General Medical Practitioner had made a referral to local ear, nose, throat (ENT) services, but no appointment had been scheduled. The patient was otherwise medically fit and well.

Following clinical and radiographic examination and assessment, the following diagnoses were made:

• UL1: ectopic and unerupted, mild-moderate root dilaceration;
• ULA: retained;
• Medical history of daily, heavy nosebleeds worsening over the previous couple of years;
• Soft tissue lesion in the left maxillary sinus closely related to unerupted UL1 (incidental finding) (Figures 13 and 14).

The following treatment was, subsequently, planned and completed:

• Prevention of caries: effective twice daily oral hygiene, reduced frequency and amount of dietary sugars and acids, 1450ppm fluoride toothpaste and regular review in primary care.
• Removal of obstruction to UL1 eruption: extraction of ULA under local anaesthetic (Figure 15a.)
• MDT assessment regarding the failure of UL1 to erupt: no spontaneous improvement 1 year after ULA extraction, decision to begin orthodontic therapy made. Completion of CBCT (Figure 14).
• Orthodontic therapy: upper and lower fixed appliances to open space at the maxillary central incisor site.
• ENT referral: new referral sent directly to ENT colleagues highlighting continued nosebleeds and the presence of a soft tissue mass within the left maxilla that appeared to extend into the nasal cavity.
• Review of UL1: spontaneous eruption of UL1 after space creation, allowing it to be brought into alignment. Orthodontic fixed appliance therapy was completed and appliances debonded for MRI scanning with the ENT team. Retainers were fitted (Figure 15b).
• ENT assessment: following MRI scan that suggested the diagnosis of maxillary sinus mucocele, endoscopic excision and drainage of lesion was performed. Histopathological assessment of surgical specimen confirmed the provisional diagnosis of a mucocele.
• Review of dental development.

Learning points

Initial management of unerupted maxillary central incisors

As recommended by RCS guidelines, the first line of management is removal of the obstruction.²⁴ Completion of this phase in primary care is essential prior to MDT assessment. Alongside space maintenance or opening of space, unerupted maxillary incisors with root growth potential are likely to erupt into the arch.

Significance of multispecialty liaison with medical ENT team

Families may find accessing health services difficult, especially during the COVID-19 pandemic when only urgent referrals were accepted. Clinicians are well placed in supporting referrals through letter correspondence detailing clinical and radiographic findings as part of the referral process.

Further research

Maxillary sinus mucocele due to dental trauma is not currently reported. Further research in this area to confirm an association could be helpful in management of similar cases, despite its rare presentation.

Conclusion

Primary dental trauma resulting in avulsion, intrusion of the primary incisor or associated alveolar fracture are more likely to result in complications affecting the successor tooth. Appropriate management of these should include regular active monitoring, parent education regarding possible sequelae, and age-appropriate referral to specialist services if required. Application of the learning points described in this article may help practitioners manage primary dental trauma and the sequelae.