Characteristics, Diagnosis and Treatment of Compound Odontoma Associated with Impacted Teeth

Abstract

Compound odontoma is a malformation typical of young adults below the age of 20, with a slight preference for the male gender and the anterior region of the maxilla. Clinically asymptomatic, it can be detected during a radiological investigation in connection with the persistence of deciduous dental elements and the impaction of definitive ones. The treatment of choice is excisional surgery and recurrence is a rare event. The need for orthodontic therapy for impacted elements is usually not necessary because in most cases, odontomas are small, circumscribed lesions the size of a permanent tooth. In this article, the diagnostic and therapeutic surgical excision procedure is presented in three patients at developmental age with large compound odontomas associated with at least one retained canine, and in two of the cases, with serious transmigration to the impacted tooth elements.

Keywords: compound odontoma; developmental age; impaction; odontoma; oral surgery; transmigration.

Figure 1

Series of images from cone beam computed tomography (CBCT). (A) Orthopanoramic CBCT view shows the persistence in the arch of the upper left deciduous canine 63 and the overlapping presence of a compound odontoma, which in its evolution blocked the eruption of the corresponding permanent canine; (B) A cross-section image highlights the permanent canine that has been displaced vestibular due to the presence of an odontoma that is palatal to the canine; (C,D) Parasagittal images that show that the odontoma completely occupies the entire thickness of the bone between the buccal and palatal cortex. Absence of bone trabeculae and displacement of the permanent canine towards the vestibulum.

Figure 2

Intra-oral photographic images at baseline. (A,B) Front and side view before surgery; (C,D) Detail in the lateral and occlusal view with a temporary prosthesis in place 23. An expansion of the bone cortex is visible in line with the odontoma and the permanent area of the canine.

Figure 3

Intraoperative images. (A) L-shaped flap with a convex indentation on element 22 and an intrasulcular incision extending to the tooth 24; (B,C) Removal of the temporary denture, exposure of the canine with a ball bone cutter (bone cutter ball head 018 Meisenger, Neuss, Germany); (D) Exposure of the canine; (E) Onset of exposure of the odontoma; (F) Enucleation of odontoma, good cutting plane visible; (G) Detail of the odontoma structures that are removed together; (H) Extensive residual bone fissure palatal to the position of the canine.

Figure 4

(A,B) Suture of the flap (Vicryl Ethicon 3.0, 17 mm 1/2c, Johnson & Johnson International, Hamburg, Germany); (C) clinical aspect of the odontoma, (Bard-Parker stainless steel size 15, Benefits srl, Genova, Italy). (A,B) The suture is visible at the level of the relief incision in the ridge; (C) various fragments of the removed odontoma are recognizable, the neoformation is organized in variously cusped denticles. The structures of the compound odontoma with crowns and roots are recognizable.

Figure 5

(A) Orthopanoramic radiography with the presence of a compound odontoma, formed by many teeth, recognizable on the radiographic image. The maintenance of the deciduous element 72 and the inclusion of the left permanent canine 33 at the lower edge of the mandible. Moreover, mesial to the location of element 33, the presence of element 32 is marked; (B) Detail of compound odontoma, the presence of all the teeth forming the new formation; (C) Cranial teleradiograph in lateral–lateral projection showing the neoformation, the width of the symphysis is completely occupied by the odontoma.

Figure 6

Series of images from cone beam computed tomography (CBCT). (A) The localization of the neoformation is anterior to the emergence of the mandibular nerve, which is at the level of element 34. During the surgical phase, the emergence of the nerve is highlighted in order to ensure its preservation. It is again possible to highlight the denticles; they are arranged with various degrees of angulation. The whole odontoma is positioned superiorly with respect to the permanent canine, which is in the inferior portion of the mandible; (B) The presence of the neoformation in the bone structure of the mandible. The vestibular cortex is thinned, absent in some places; (C) Axial slices showing lesion-thinning cortical plates and the compound odontoma occupying the entire sagittal thickness of the mandible in the upper part. Visible are the tooth-like structures, some fused together, others not fused, with different sizes. Canine 33 and lateral incisor 32 have been moved towards the mandibular caudal cortex in a more horizontal position, certainly raised by canine 33, presenting with hyperplastic dental follicle.

Figure 7

Intraoperative images. (A) “L”-shaped flap with the first incision with a distal discharge cut at 43 and then the other intrasulcular incisor along all the lower incisors, including the deciduous one, up to the level of 34; (B) Complete skeletonization of the bone. A veil of cortical bone above the odontoma is present; (C) Removal of the bone covering the odontoma and the various denticles are extracted (D–G), on the images the denticules appear with a cluster or a cauliflower organization; (F) A slight capsule outside the odontoma is present; there is a good cleavage plane with respect to the underlying bone and there are no adhesions; (H) Complete removal of the compound odontoma; (I) The lower portion of the included canine begins to be seen. The crown of the canine is freed using the bone burs (bone cutter ball head 018 Hager & Meisinger GmbH, Neuss, Germany) on a straight handpiece (KaVo TYP Surgical straight handpiece dental, Genova, Italy), then the root (J,K) is also cut and extracted, as otherwise it would have been extremely difficult to extract the whole tooth; (L) Extension of the area and of the large bone defect following the surgical removal of the odontoma and the included dental elements.

Figure 8

Post-surgery images. (A) The bone defect is filled with a fibrin sponge (Spongostan Dental, absorbable haemostatic gelatine sponge, Ethicon, Somerville, MA, USA), which guarantees a good clot; (B) The suture (Vicryl Ethicon 3.0, 17 mm 1/2c, Johnson & Johnson International, Hamburg, Germany) that recomposes the nature of the tissues is visible; (C) The odontoma clinical findings consisting of an ensemble of calcified structures, some like mini-teeth, some denticles appear as single-rooted, others as multi-rooted, some even fused, with no complete root formation and enamel, dentin, and cement being identified as dental tissues. (D) The orthopanoramic image after 6 months showing the progressive reconstruction of the bone anatomy of the area. The odontoma resulted in both dislocation and subsequent inclusion of 32 and 33, but also caused root displacement of 31, 41, and 34. Any type of orthodontic therapy is postponed; not only is bone formation required at all the entire area resulting from the surgical removal of the odontoma, but it is also necessary to check the vitality of the dental elements adjacent to the area itself.

Figure 9

(A) Orthopanoramic image of the dental arches. The inclusion of the lower left canine, element 33, and the presence of at least four denticles are noted. The organization of a new formation is a little different than in the previous cases; (B) Details of the pre-operative orthopanoramic on the left. This seems less organized as can be seen in detail in (B); the various denticles seem less circumscribed and more scattered in the bone structure. The presence of the neoformation determined the inclusion of the tooth; there are no agenesis.

Figure 10

Series of images from cone beam computed tomography (CBCT) prior to the surgery. (A) The crown of the impacted canine 33 deforms the vestibular profile of the mandible; (B,C) Parasagittal images of the odontoma; (D) Parasagittal images, the canine can be seen in the vestibular position; (E) Three-dimensional reconstruction confirms the position of the canine which is at the level of the right central incisor 41; (F) Detail of the orthopanoramic image, showing the position of the canine in close contact with the root apexes of the central incisors, 41 and 31, and also partially of the lateral ones, 32 and 42.

Figure 11

Intraoral photographic documentation before surgery. (A) Frontal view; (B) Particular of the frontal view in correspondence of the impacted canine upper area.

Figure 12

Pictures of the surgical procedure. (A) Flap design performed with the relief cut distal to 43, then within the gingival sulcus of the incisors; (B) After full thickness buccal flap the skeletonization of the bone, the included tooth is already visible, the bone is removed to remove the fibrotic sac present around the crown; (C) The crown is fully exposed; (D–E) To make it possible to extract the impacted canine, the tooth is cut, then the crown is extracted first and then the root; (F) After completing the extraction, the residual bone cavity and dental structure, if visible, is analysed. In this case, the root apex of 41 is visible and the vitality of this tooth will be evaluated during the follow-up; (G) The denticles of the odontoma begin to be exposed. In this case, there are only 4 single neoformations positioned in the bone structure and detached from each other, thus being even more difficult to find because they were not all four fused together.

Figure 13

Post-operative images. (A) Frontal intraoral image with the suture of the flap (Vicryl Ethicon 3.0, 22 mm 1/2c, Johnson & Johnson International, Hamburg, Germany); (B) Image of the extracted canine; (C,D) The four extracted denticles which were part of the odontoma.