Paediatric odontogenic myxoma (OM) is a rare pathological condition in the oral and maxillofacial region. There has been much debate in the literature regarding the preferred method of treatment; however due to the rare nature of this disease, definitive algorithms of management are yet to be determined. A case series of eight paediatric patients with OM is presented. Six of the lesions were in the maxilla and two were mandibular lesions. The patients were aged between 2 and 18 years. Treatment ranged from excision and the application of Carnoy’s solution to segmental resection and reconstruction. From this case series it can be seen that even in situations where treatment was limited to excision and the application of Carnoy’s solution, no recurrences occurred. As such the present authors favour an initially more conservative approach to the management of these lesions where possible and reserving conventional resective treatment for recurrences, lesions causing pathological fracture, and those in regions that are difficult to access.
Since first described in 1947 by Thoma and Goldman, odontogenic myxoma (OM) has remained a management dilemma for oral and maxillofacial surgeons. It is a rare, benign odontogenic tumour of mesenchymal origin that is not encapsulated and exhibits variable clinical behaviour with differences in the reported rate of recurrence.
Clinically, the OM is often asymptomatic or presents as a firm expansile mass in the maxillofacial complex, with or without displacement or mobility of the associated dentition. There is an equal distribution between the maxilla and mandible. Its incidence is approximately 0.07 per million people and it makes up approximately 0.5–20% of odontogenic tumours in adults and 8.5–11.6% in children.
Various terms have been used to describe the radiological features of OM, such as ‘soap bubble’ and ‘honeycombing’, yet none are pathognomonic. Lesions may be unilocular or multilocular and may be either well-defined or poorly demarcated. These lesions can cause expansion of the bony cortex and displacement or resorption of associated teeth. Histopathological features include spindle-, wedge-, or stellate-shaped cells that are loosely arranged in an abundant mucoid background.
There is no consensus as to the mechanism of tumour infiltration, although several hypotheses have been suggested. These include the expression of matrix metalloproteinases, genetic alterations, the expression of anti-apoptotic proteins, and alterations in receptor activator of nuclear factor kappa B ligand (RANKL), its receptor, and osteoprotegerin.
Due to the relatively low incidence of OM and its variable clinicopathological behaviour, it has been difficult to establish a definitive management algorithm and there is no widely accepted consensus. Current recommendations for treatment vary from enucleation to surgical resection with 1-cm margins. In the paediatric population, if a more radical surgical intervention is advocated, consideration must be given to the impact on growth and development, as well as impairment secondary to the ablation of vital structures.
The aim of this retrospective study was to review cases of OM in children treated at a children’s hospital in Melbourne, Australia between February 2004 and February 2016 and to evaluate the mode of presentation, radiological findings, and outcomes of treatment. Approval for this study was obtained from the necessary ethics committee.
Materials and methods
A retrospective analysis of the oral and maxillofacial surgery database was performed by manual and electronic search using Microsoft Excel. This search yielded eight cases seen over a 12-year period. The inclusion criterion was any child treated for OM at the hospital; no exclusion criteria were applied to the dataset. The age and mode of presentation, radiological findings, operative approaches, and outcomes during the follow-up period were extracted from the patient records and analysed.
Clinical presentation and diagnosis
In this series, the age at presentation ranged from 2 to 18 years ( Table 1 ). Maxillary lesions were more common in the younger age group, with all cases except one being ≤11 years of age; these presented as asymptomatic, firm, painless swellings over the maxilla. In contrast, mandibular lesions in this series occurred in older patients and were incidental radiological findings during routine orthodontic or dental care. There were no associated signs or symptoms such as pain, mobility of teeth, or paresthesia.
|Patient||Age (years)||Presentation||Imaging||Treatment||Follow-up (months)||Recurrence|
|1||2||Painless firm swelling in the right anterior maxilla||CT: well-defined, expansile cystic lesion in the right maxilla/paranasal area||Right partial maxillectomy and costochondral rib graft reconstruction||103||Nil|
|2||2||Swelling in the right infra-orbital area with epiphora||CT: well-defined expansile cystic lesion in the right anterior maxilla/paranasal area||Excision, peripheral ostectomy, and application of Carnoy’s solution||44||Nil|
|3||2||Left nasomaxillary facial swelling||CT: multiloculated radiolucency with bony expansion in the left paranasal area causing displacement of the developing dentition||Enucleation, curettage, and Carnoy’s solution||10||Nil|
|4||11||Swelling over the right maxilla||DPR and CT: well-defined, expansile mass with multiple internal septations in the right posterior maxilla||Right partial maxillectomy and DCIA reconstruction||30||Nil|
|5||13||Painless swelling in the left maxillary sulcus, with mobile 27||DPR: left maxillary radio-opacity with displaced 28
CT: well-defined mass occupying the left maxillary sinus, extending to the orbital floor and pterygoid plates
|Left sub-total maxillectomy with intraoral and infratemporal approach and DCIA reconstruction||132||Nil|
|6||16||Incidental finding of unilocular radiolucency between 35/36||DPR/CBCT: unilocular radiolucency between 35/36 without displacement||Marginal resection with immediate bone grafting||7||Nil|
|7||16||Mobile symptomatic deciduous tooth in the left maxilla||DPR and CT: Ill-defined radio-opacity involving the left maxillary sinus||Left subtotal maxillectomy and DCIA reconstruction with temporal artery anastomosis||48||Nil|
|8||18||Painless swelling in the left mandible||DPR: unilocular radiolucency of the left mandible involving 34/35/37/38
CT: expansile, lytic lesion in the left mandible with cortical breech and soft tissue extension
|Enucleation, removal of 34/35/37/38 with Carnoy’s solution||12||Nil|