Repair of a defect following the removal of a maxillary adenomatoid odontogenic tumor using guided tissue regeneration. A case report

Adenomatoid odontogenic tumor mimicking a lateral periodontal cyst - A rare case report in the mandible

Adenomatoid odontogenic tumor (AOT) is benign tumor of the oral cavity characterized by its slow growth accounting to 3%-7% of the odontogenic tumors. AOTs mostly occur in the maxillary anterior region and most often than not associated with impacted anterior teeth. It affects the younger age group, especially below 20 years and is commonly seen in females. It occurs as two main variants - (a) central/intraosseous which is more common and (b) peripheral which is rare. The location of the lesion, its association with the impacted tooth, is the basis for the classification of AOT. The intraosseous type may be related to unerupted tooth (follicular variant) or may not be related to unerupted tooth (extra-follicular variant). Radiologically, AOT presents predominantly as a unilocular cystic lesion enclosing the unerupted tooth. The lesion presents rarely with a cystic component. Radiopacities on the intraoral periapical radiograph are seen as discrete foci having a flocculent pattern within radiolucency even with the presence of minimal calcified deposits. AOT being benign in nature is enucleated with least chances of recurrence. Here, we present a rare case of extra-follicular variant of adenomatoid odontogenic tumor in a 19-year-old female patient.

Maxillary adenomatoid odontogenic tumor associated with a premolar

The adenomatoid odontogenic tumor (AOT) represents 3-7% of all odontogenic tumors, and over 750 cases have been reported in the literature. This lesion was formerly considered to be a variant of the ameloblastoma and was designated as adenoameloblastoma. These lesions may infrequently produce dentinoid material and rarely enamel matrix. Consequently, the WHO (2005) classification of odontogenic lesions considered this process to represent a mixed odontogenic neoplasm. We present a case of a 12-year-old female patient with an AOT of diameter 5 cm × 5 cm located in the anterolateral region of the maxilla in association with an impacted premolar tooth. The rarity of AOT, association of this lesion with regards to maxillary premolar, the exaggerated size at presentation, the eruption of the displaced canine postoperatively and uneventful healing of the bony defect without adjunctive therapy makes this case unique.

Critical evaluation of the radiological and clinical features of adenomatoid odontogenic tumour

OBJECTIVES

The aim of this study was to evaluate the radiological and clinical features of adenomatoid odontogenic tumours (AOTs).

METHODS

A total of 272 cases (267 from the English-language literature and 5 new cases) were analysed with special emphasis on their radiological features.

RESULTS

The patients' ages at time of diagnosis ranged from 3 years to 82 years (mean 18.4 years). The maxilla-to-mandible ratio was 1.7:1. Mandibular lesions were significantly more frequent among patients older than 16 years (p = 0.032). Expansion of the cortex was significantly more prominent among patients older than 16 years (p = 0.045). There was a positive correlation between the size of the lesion and the age of the patient at the time of diagnosis (p = 0.016). The size was also associated with increased root resorption (p < 0.001), ill-defined borders (p < 0.001), expansion (p < 0.001) and perforation of the cortex (p < 0.001). Small opacities were present in 77% of lesions and were associated with expansion of the cortex (p = 0.043). The significant radiological features in patients aged 30 years and above were root resorption (p = 0.013) and lesions crossing the midline (p = 0.019).

CONCLUSIONS

The size of an AOT is influenced by the patient's age. It is also associated with root resorption, ill-defined borders, expansion and perforation of the cortex, but it cannot be ruled out that those changes reflect a longer duration of the lesion.

Adenomatoid odontogenic tumor associated with dentigerous cyst in posterior maxilla: A case report and review of literature

Adenomatoid odontogenic tumor (AOT)-a benign (hamartomatous) lesion of odontogenic origin-is an uncommon tumor which affects young individuals with a female predominance, mainly in the second decade. This lesion is most commonly located in the anterior maxilla and is usually associated with an impacted canine tooth. This is a case report of a 39-year-old female patient presented with a large AOT of the posterior maxilla associated with an impacted second molar - a very rare situation.

Superficial topography and porosity of an absorbable barrier membrane impacts soft tissue response in guided bone regeneration

BACKGROUND

Surface topography and porosity of barrier membranes is suggested to impact the soft and hard tissue response. In this study, the specific soft and hard tissue response characteristics of a synthetic polylactide membrane are evaluated including soft tissue inflammation, osteogenesis, and osteopromotion.

METHODS

Analysis of porosity and surface topography of the test material was performed by scanning electron microscopy. Transosseous parietal defects were surgically created bilaterally in 32 BalbC/ByJ mice and treated either with the barrier (test) or sham-operated (control). Healing was assessed histologically and histomorphometrically with quantification of bone bridging.

RESULTS

Scanning electron microscopy analyses of the barrier revealed a microstructure resembling cancellous bone. Interconnecting pores and channels, measuring between 6 and 60 microm in diameter, formed by smooth internal walls were observed throughout the device. Two distinct patterns of porosity were observed. The external surface of the membrane was characterized by a highly porous structure, with minimal interporous nodes and average pore sizes ranging between 6 and 20 microm in diameter. The internal surface was characterized by a minimal porous structure, with significant interporous nodes and average pore sizes ranging between 18 and 60 mum in diameter. Histomorphometric analyses demonstrated increased bone bridging by 60% and 300% in membrane-treated sites after 14 and 28 days of healing, respectively. The rough surface of the barrier contained significantly more giant cells, whereas the smooth surface contained significantly more inflammatory cells.

CONCLUSION

The surface topographies engineered on different sides of the barrier promote differential soft tissue responses leading, however, to similar amounts of enhanced bone formation.

Rare peripheral odontogenic tumors: report of 5 cases and comprehensive review of the literature

Peripheral odontogenic tumor (POT) is a rarely encountered lesion. We report 5 cases of POT including adenomatoid odontogenic tumor (AOT), keratocystic odontogenic tumor (KCOT), ameloblastic fibroma (AF), developing odontoma (DO), and calcifying cystic odontogenic tumor (CCOT), and also provide a review of relevant literature to define the tumor profile. Except for PCCOT with enough frequency (>100 cases), PAOT (n = 14), PKCOT (n = 15), PAF (n = 5), and PDO (n = 7) were scarce in the literature. As to the age distribution, PAOT, PAF, and PDO fell within the first 2 decades, whereas PKCOT arose in middle-aged adults. A marked female predominance was apparent in PAOT, PKCOT, and PAF. Approximately 90% of PAOT occurred in the maxilla. PAOT and PDO arose primarily in the incisor area, and PKCOT and PAF were typically located in permanent canine/premolar and deciduous molar regions, respectively. Although most PAOT and all PKCOT affected the buccal gingiva, PDO showed a strong predilection for the lingual aspect. With the exception of PKCOT, there was no propensity for recurrence in the above POT. At this time, it remains to be determined whether the biologic behavior of PKCOT is the same as for KCOT. In view of the reported cases, a true extraosseous origin of PAOT and PAF, for the most part, is challenging.

Use of guided tissue regeneration in the treatment of a lateral periodontal cyst with a 7-month reentry

BACKGROUND

The lateral periodontal cyst (LPC) is an unusual cyst of odontogenic origin, most frequently encountered in the mandible between the roots of canines and premolars. The most common treatment for LPC is surgical enucleation. This article reports a case of an LPC treated with guided tissue regeneration (GTR) and bone allograft.

METHODS

A 74-year-old woman presented for periodontal examination. Radiographs revealed a cystic lesion with LPC characteristics. After surgical incisions and flap reflection, the cyst was removed and sent for biopsy. Because of the anatomy of the resulting intrabony defect, GTR was considered the ideal treatment.

RESULTS

The biopsy revealed the histologic features of an LPC. Radiographs at 7 months post-treatment indicated bone fill of the initial defect. Although some attachment loss occurred, the reentry demonstrated a high percentage of bone fill of the defect after 7 months.

CONCLUSION

Depending on the anatomy of the defect left after the removal of an LPC, GTR, along with bone grafting, can be a very useful tool for its treatment by reducing the attachment loss observed after simple enucleation of the cyst.

An updated clinical and epidemiological profile of the adenomatoid odontogenic tumour: a collaborative retrospective study

BACKGROUND

Adenomatoid odontogenic tumour (AOT) is a benign odontogenic jaw lesion. The aim of this study was to update the biological profile of AOT.

MATERIAL AND METHODS

Cases published in the literature and cases in files of co-authors were included.

RESULTS

550 new cases were retrieved, and of a total of 1082 cases analysed, 87.2% were found in the second and third decades. The M:F ratio was 1:1.9. 70.8% were of the follicular variant (extrafollicular: 26.9%, peripheral: 2.3%). 64.3% occurred in the maxilla. 60% of follicular AOTs were associated with unerupted canines. Nineteen cases of AOT (2.8%, M:F ratio was 1:1.4) were associated with embedded third molars. Twenty-two peripheral AOTs (2.3%, M:F ratio was 1:5.3) were recorded. The relative frequency (RF) of AOT ranged between 0.6% and 38.5%, revealing a considerably wider AOT/RF range than hitherto reported (2.2-7.1%).

CONCLUSIONS

This updated review based on the largest number of AOT cases ever presented, confirms the distinctive, although not pathognomonic clinicopathological profile of the AOT, its worldwide occurrence, and its consistently benign behaviour.

Repair of an intrabony defect from an adenomatoid odontogenic tumor

This case report describes the occurrence and treatment of an adenomatoid odontogenic tumor (AOT) presenting as a periodontal intrabony defect on a upper lateral incisor. Following incision and flap reflection, a solid, rubbery specimen was enucleated in one piece leaving a wide moat-like intrabony defect. A bioabsorbable membrane of glycolide and lactide copolymer was sutured over the defect to maximize regeneration and the flaps then sutured over the membrane. Microscopic analysis of the biopsied specimen revealed dental hard tissue interspersed in a field of odontogenic epithelium in a glandular configuration, consistent with a diagnosis of AOT. AOT is a rare odontogenic tumor usually associated with unerupted teeth or dentigerous cysts, not periodontal defects. Clinical evaluation 6 months postoperatively revealed restoration of clinical attachment and periodontal health.

Efficacy of high-density versus semipermeable PTFE membranes in an elderly experimental model

OBJECTIVE

The clinical effectiveness of expanded polytetrafluoroethylene (PTFE) membranes for guided bone regeneration has been reported in the literature on several occasions. However, one major drawback of this material is the need for a second surgical operation for removal of the membrane. In addition, most studies involving guided bone regeneration in animal models have used young animals or animals of unspecified age, but in some clinical situations guided bone regeneration may be indicated in elderly jaw bones. The objectives of this investigation were (1) to evaluate the effectiveness of a newly introduced high-density PTFE membrane (TefGen-FD)-a material that does not require second-stage surgery for its removal-for enhancement of bone ingrowth in elderly rabbits' calvaria and (2) to compare the findings with those obtained with the commonly used semipermeable expanded PTFE membrane (Gore-Tex).

STUDY DESIGN

Eighteen elderly rabbits (each more than 30 months old) served as the experimental animals in this study. Two non-self-healing, full-thickness defects were created in each rabbit calvarium. One of the 2 defects was fully covered with macroprous expanded PTFE membrane (Gore-Tex); the other defect was covered with microporous PTFE membrane (TefGen-FD). Specimens were obtained at 4, 8, and 16 weeks and examined by means of light microscopy.

RESULTS

Clinically, the high-density TefGen membrane was much easier to detach from the underlying bone than was the semipermeable Gore-Tex membrane, which showed strict adherence to bone surface on removal. Microscopically, the Gore-Tex membrane lamellae were infiltrated by fibro-osseous tissue at the membrane's lower surface. A relatively greater speed and quantity of bone regeneration were observed in the defective cavities covered with Gore-Tex membrane than in those covered with TefGen membrane.

CONCLUSIONS

It appears that the semipermeable Gore-Tex membrane is more effective than the high-density TefGen-FD membrane with respect to guided bone regeneration in elderly bone. These findings have relevance for the clinical situation of using guided bone regeneration in conjunction with implant placement and ridge augmentation procedures in atrophic elderly jaws.