Ghost teeth: Regional odontodysplasia of maxillary first molar associated with eruption disorders in a 10-year-old girl.

Regional odontodysplasia (RO) is an uncommon, developmental anomaly of the dental hard tissues that affects ectodermal and mesodermal dental components with characteristic clinical and radiographic findings. Clinically, RO affects a particular segment in either or both dentitions in the maxilla or mandible or both jaws. Radiographic features have consistently demonstrated thin and defective layers of enamel and dentine, resulting in a faint, fuzzy outline, creating a ghost-like appearance. The RO etiology is uncertain; numerous factors have been suggested and considered as local trauma, irradiation, hypophosphatasia, hypocalcemia, hyperpyrexia. A case of RO in a 10-year-old girl whose chief complaint were forwardly placed upper front teeth and the absence of eruption of permanent teeth. Clinical and radiographic features are described.

Regional odontodysplasia (ROD) is a relatively rare dental anomaly. The clinical manifestations of odontodysplasia[1] are:

Localized occurrence within a particular segment in either or both dentitions

Hypocalcification and hypoplasia of the enamel and dentin

Discolored, small, and distorted affected teeth with various surface markings (e.g., irregular contour with surface pits and grooves and yellowish or brownish discoloration)

Delayed or failed eruption due to arrested root formation.

The radiographic features have consistently demonstrated thin and defective layers of enamel and dentin, resulting in a faint, fuzzy outline, creating a ghost-like appearance. The pulp chambers and canals are enlarged, and the roots appear short and stubby with open apices. True and false denticles may be seen in the pulp of affected teeth as well as adjacent, clinically normal teeth.[1]

The first report of this condition was published by McCall and Wald[2] in 1947, but the term “odontodysplasia” was introduced by Zegarelli et al.[3] in 1963. Since that time, a number of cases have been described under a variety of names; such as localized arrested tooth development, familial amelodentinal dysplasia, unilateral dental malformation, regional odontodysplasia, ghost teeth, odontogenesis imperfecta, and amelogenesis imperfecta[4] and Published cases suggest ROD occurs more frequently in females, with no racial predilection. The condition can affect both primary and permanent dentitions and can occur either in the upper jaw or lower jaw or both. Maxilla is involved twice as often. Although the incisors and canines are most often involved, any tooth may be affected. When primary teeth are involved, the permanent successors are also usually affected.[1] The condition tends to affect several adjacent teeth within a particular quadrant. Lustmann et al.[5] found that affected teeth were located on both sides of the midline in only 11 of the 51 cases reported. ROD is usually seen in consecutive teeth, with no normal teeth interposed, although occasional skipped or minimally affected teeth do occur in the permanent dentition. Permanent first molars are affected only if the adjacent primary molar exhibits ROD.[6]

Multiple etiologies have been proposed, with defective vascular function the most widely accepted. The association of vascular nevi in the facial skin overlying areas where ROD occurs suggests that a local vascular defect may be involved in the pathogenesis of ROD. These nevi are pale pink in color and disappear gradually with age.[6]

Other conditions which share some characteristics with ROD include dentinal dysplasia types I and II, shell teeth, rickets, hypophosphatasia, amelogenesis imperfect, and dentinogenesis imperfecta. However, it should be noted that unlike ROD, all these conditions affect the entire dentition rather than a localized area. Turner's teeth should be considered if only one or two permanent teeth are affected.[1]

When RO is observed in the primary dentition, teeth can be erupted, hypoplastic, hypocalcified, with changes in color and contour. Affected teeth are likely to be malformed, discolored, grooved, and hypoplastic. Gingival tissue can be hyperemic and usually presents a fistula. In the permanent dentition, teeth usually are not erupted or can be partially erupted with fibrous gingival tissue covering.[17]

Histologically, areas of hypocalcified enamel are visible, and enamel prisms appear in irregular direction. Coronal part of dentine consists of clefts and a reduced number of dentinal tubules; radicular dentin is generally more normal in structure and calcification. Pulpal calcification of various degrees is also commonly seen. The mineral content of the affected enamel has been found to be higher than that of dentin in microradiographic studies.[7]

This article reports a case of regional odontodysplasia of the deciduous and permanent tooth associated with eruption disorders.

Case Report

A 10-year-old girl [Figure 1] attended the author's pediatric dental clinic with a chief complaint of the absence of eruption of the permanent tooth with associated pain, and swelling in the upper left back tooth region. Her prenatal, birth, medical, and family history was unremarkable. Extraoral examination revealed nothing of note. The girl was at late mixed dentition stage.

Figure 1

Extraoral – Frontal view of the patient

Intraoral clinical examination revealed [Figure 2] a well-defined edematous and fibrous gingival tissue covering an expanded alveolar bone (6 mm × 8 mm) in the region of 65 and 26. On examination, the tooth 26 [Figure 2] was partially erupted with only its cuspal portions visible and exhibited an irregular contour with lots of shallow furrows pits and grooves. The tooth was extremely tender on percussion and pain on palpation of the surrounding gingiva was also noted. According to the patient's previous dental history, we noted that upper left primary 2nd molar also exhibited similar morphological deformity and got exfoliated 2 years back.

Figure 2

Intraoral clinical picture of regional odontodysplasia

lntraoral periapical (IOPA) [Figure 3] of the affected area followed by orthopantomogram [Figure 4] of the patient was obtained.

Figure 3

lntraoral periapical of the affected tooth (26)

Figure 4

Orthopantomogram of the affected tooth (26)

Radiographic findings

Dental development from radiographs appeared age-appropriate and showed the normal thickness of enamel and dentine in maxillary and mandibular primary and permanent dentitions [Figures 3 and 4]. However, 26 indicated ghost-like appearance with thin layers of enamel and dentine, short roots with wide open apex, and enlarged pulp chambers [Figure 3]. The left maxillary primary second molar (65) had exfoliated before 2 years due to a similar defect and IOPA of the affected side shows indistinct and irregular periapical radiolucency of 26. Developmental defects in erupting 2nd premolar (25) bud were also noted in IOPA [Figure 3].

Treatment

As the tooth 26 was infected with periapical abscess and could not be restored effectively treatment plan was to extract the tooth. Surgery was accomplished under local anesthesia using the mucoperiosteal flap technique via a vestibular approach. Extraction of the dysplastic permanent teeth, alveolar curettage, irrigation of the surgical site, and flap replacement were performed. The extracted tooth's cuspal portions had irregular contour with lots of shallow furrows, pits and grooves [Figure 5]. Roots were short with thin layers of enamel and dentine, with wide open apex (blunderbus canals). [Figure 6]. Fibrous gingival tissue was removed, and before sutures were placed, a section of the fibrous gingiva and a bone fragment in the area of regional odontodysplasia were obtained and immersed in 10% formaldehyde preservative. The tissue biopsies were sent to histopathological analysis to confirm the clinical and radiographic diagnosis of RO.

Figure 5

Occlusal view of extracted tooth

Figure 6

Extracted tooth showing short roots with blunder bus apex

The biopsy of the gingival fragment showed the presence of islets of odontogenic epithelium in the connective tissue as well as some fibrosis. The patient was placed on periodic recall to observe the progress of eruption of other teeth and to monitor the growth and development of maxillary and mandibular dental arches.

Discussion

Regional odontodysplasia is a rare, localized developmental anomaly of the dental hard tissues of a group of contiguous teeth. Many cases are probably misdiagnosed as malformed teeth or odontomas. It occurs in both the dentitions, and it has more predilection for the maxilla.

The etiology of RO is still unknown, and such conditions as metabolic disturbances, Rh incompatibility, viral infections, local trauma, vascular defects, irradiation, and medications during pregnancy have been suggested as possible causes. Some patients may also present with systemic anomalies, like facial asymmetry. In the current case, etiologic factors could not be identified, and no systemic involvement was seen. Although dentinal dysplasia, amelogenesis, and dentinogenesis imperfecta show some similar characteristics as regional odontodysplasia, these conditions affect the entire dentition in contrast to the segmental involvement seen in RO.

Histologically, all structures of the tooth germ are affected. In the ground section, the enamel is of varying thickness, producing an irregular surface. The enamel prisms are irregular and show hypoplastic and hypocalcified areas, whereas, the enamel closer to the dentinoenamel junction appears more normal. Invagination extending from the enamel surface into the dentin has been reported. The dentinoenamel junction is scalloped and irregular. The dentin is thin, and the tubules are reduced in number and tortuous in shape. The most significant feature is the presence of large areas of amorphous dentin containing irregularly shaped foci of a poorly formed dentinal matrix, within which, capillaries are sometimes present. Interglobular dentin and globular masses interrupting the dentinal tubules are frequently seen. Amorphous areas within the coronal dentin are usually evident. Prominent interglobular dentin is also seen in radicular dentin.[89]

Treatment of RO has given rise to controversy, the main concern being whether to remove the affected teeth. The rationale for early extraction is that many of the anomalous teeth are not restorable and would develop dental abscess soon after eruption. On the other hand, retaining noninfected teeth helps maintain the height of alveolar bone, avoids the need for a removable prosthesis and eliminates the psychologic effects of premature tooth loss.[9]

Most clinicians advocate extracting the affected teeth as soon as possible and inserting a prosthetic replacement. Some clinicians prefer restorative procedures if possible, to protect the affected erupted teeth. However, selection of method and timing appear to be critical factors in the treatment of RO. Although in very young children, teeth in the arch should be retained, teeth involved with abscesses cannot be restored, and need to be extracted. In contrast, in older children, abscessed permanent teeth should be extracted with others retained until final rehabilitation with implants and/or fixed prosthesis.[9] As mentioned by Cahuana et al.[10] in their article in 2005, they stated that in a child with RO, conservative treatment should be applied to preserve the affected teeth for as long as possible to provide normal jaw development. Several reports state that if severely infected teeth are present, they should be extracted, and edentulous areas should be restored with acrylic removable appliances to:

Maintain esthetic and masticatory functions

Avoid over eruption of opposing teeth

Achieve space preservation and normal vertical dimension

Lessen the psychological effects of premature tooth loss.

Despite the increasing use of osseointegrated implants in patients with missing teeth, their use is contraindicated in growing patients. Implants are preferably placed after pubertal growth.

Melamed et al.[11] however, presented a conservative multidisciplinary approach to the treatment of a ROD case in the mixed dentition. This article proposed a treatment and restorative technique for ROD involving multiple primary teeth. Prosthetic restoration with partial dentures is important for these patients to provide chewing function, normal vertical dimension, space preservation, and improved esthetics. The use of a removable partial denture with soft liner aids retention by surrounding the supporting teeth, which lack undercuts for wire clasps.

Conclusion

The presentation of this case helps clinicians to review special clinical and radiographic features of regional odontodyplasia or ghost teeth as the condition is referred to commonly. The therapeutic considerations of RO should be based on the degree of the anomaly, presence of infection, age of the patient the functional and esthetical needs of each case. Individual management is required until the patient reaches the age for prosthetic rehabilitation.