Variants of the adenomatoid odontogenic tumor with a note on tumor origin

Three rare variants of the adenomatoid odontogenic tumor (AOT) are described. A follicular AOT associated with an impacted and displaced 28, an extra-follicular variant mimicking a radicular cyst around the apex of 23 and a peripheral (epulis-like) variant exhibiting a periodontal bone defect palatal to 21. On reappraisal of the origin and pathogenesis of the AOT, it would seem that this tumor or hamartomatous lesion is derived from odontogenic epithelium of the dental lamina complex or its remnants.     

Reconstructive periodontal therapy with simultaneous ridge augmentation. A clinical and histological case series report

Treatment of intrabony periodontal defects with a combination of a natural bone mineral (NBM) and guided tissue regeneration (GTR) has been shown to promote periodontal regeneration in intrabony defects. In certain clinical situations, the teeth presenting intrabony defects are located at close vicinity of the resorbed alveolar ridge. In these particular cases, it is of clinical interest to simultaneously reconstruct both the intrabony periodontal defect and the resorbed alveolar ridge, thus allowing insertion of endosseous dental implants. The aim of the present study was to present the clinical and histological results obtained with a new surgical technique designed to simultaneously reconstruct the intrabony defect and the adjacently located resorbed alveolar ridge. Eight patients with chronic advanced periodontitis displaying intrabony defects located in the close vicinity of resorbed alveolar ridges were consecutively enrolled in the study. After local anesthesia, mucoperiosteal flaps were raised, the granulation tissue removed, and the roots meticulously scaled and planed. A subepithelial connective tissue graft was harvested from the palate and sutured to the oral flap. The intrabony defect and the adjacent alveolar ridge were filled with a NBM and subsequently covered with a bioresorbable collagen membrane (GTR). At 11-20 months (mean, 13.9+/-3.9 months) after surgery, implants were placed, core biopsies retrieved, and histologically evaluated. Mean pocket depth reduction measured 3.8+/-1.7 mm and mean clinical attachment level gain 4.3+/-2.2 mm, respectively. Reentry revealed in all cases a complete fill of the intrabony component and a mean additional vertical hard tissue gain of 1.8+/-1.8 mm. The histologic evaluation indicated that most NBM particles were surrounded by bone. Mean new bone and mean graft area measured 17.8+/-2.8% and 32.1+/-8.3%, respectively. Within their limits, the present findings indicate that the described surgical approach may be successfully used in certain clinical cases to simultaneously treat intrabony defects and to reconstruct the resorbed alveolar ridge.     

Adenomatoid Odontogenic Tumor (AOT) Arising from a Dentigerous Cyst: Literature Review and Report of a Case

Adenomatoid odontogenic tumor (AOT) is an uncommon benign tumor of odontogenic origin composed of odontogenic epithelium in a variety of histopathological patterns. These lesions are usually solid but are occasionally cystic. AOT has been reported to occur in association with odontogenic cysts. Very few cases have been described that arise in association with a dentigerous cyst. A systematic search of the English-language medical literature in PubMed and Medline search (keywords adenomatoid odontogenic tumor, dentigerous cyst) data bases revealed only ten such cases.The present case is very unique, exceptional and first of this kind that occurred in the posterior mandible associated with an impacted lower first premolar in a 19-year old female patient. The intraosseous follicular AOT, as this case reported here, frequently resemble dentigerous cysts. There is an uncertainty whether the lining of an associated cyst represents a true dentigerous cyst, cystic change within an AOT or may represent a distinct entity. We believe that this case represents an odontogenic cyst with neoplastic change. Hence, in such cases, the final diagnosis should be made on the basis of histological examination of extensive tissue sampling of entire excised tissue specimen. Further studies to determine whether the AOT derived from an odontogenic cyst could represent a distinct variant are to be done.     

Analysis of 55 cases of adenomatoid odontogenic tumor in an Indian population and review of literature

Background This study reviews the demographic, clinical and radiographic features of adenomatoid odontogenic tumor(AOT) diagnosed in an Indian population over 50 years and also evaluate and compare follicular AOT(F-AOT) and extra-follicular AOT(EF-AOT).Material and Methods 55 diagnosed cases of AOT from 1971-2020 were studied retrospectively. The data regarding the age, sex, location, variant of AOT, duration, clinical features, radiographic appearance, treatment and recurrence were collected and analysed.Results Of the 722 odontogenic tumors diagnosed, 7.6% were AOTs with higher prevalence of extra-follicular (67.3%) than follicular (32.7%) variant. All the tumors were intraosseous with a marked predilection for maxilla over mandible, ratio 2:1. The patients mean age was 19.8 years with slightly higher female predilection (male:female ratio - 1:1.5). The anterior region (76.4%) was more frequently affected and entire quadrant was involved in 21.8% cases. Clinically, asymptomatic, slow-growing swelling was seen in 81.8% cases with duration of 15 days to 10 years. Radiographically, AOT appeared as well-corticated radiolucent lesion. Canine was the most commonly impacted tooth. Recurrence was seen in 3 cases.Conclusions Interestingly, in this series extra-follicular was twice more common than follicular AOT. Few cases involved the entire quadrant or crossed the midline of either jaws. Key words:Adenomatoid odontogenic tumor (AOT), follicular AOT, extrafollicular AOT, Indian population, odontogenic tumor.     

Clinical and histologic evaluation of a granular bovine bone biomaterial used as an adjunct to GTR with a bioresorbable bovine pericardium collagen membrane in the treatment of intrabony defects

Background: The aim of the present study is to evaluate the clinical and histologic healing of deep intrabony defects treated with guided tissue regeneration (GTR) with a collagen membrane from bovine pericardium and implantation of granular bovine bone biomaterial. Methods: Thirty patients with one deep, combined 1‐ and 2‐wall intrabony defect exhibiting a probing depth ≥6 mm and an associated intrabony defect ≥3 mm were treated with GTR with a bioresorbable collagen membrane from bovine pericardium and adjunct implantation of a granular bovine bone biomaterial. The clinical results were evaluated 1 and 3 years after surgery. In addition, five teeth fulfilling the inclusion criteria but scheduled for extraction because of advanced periodontitis or restorative considerations were treated similarly and then extracted along with a portion of their surrounding periodontal tissues for histologic evaluation 6 months after surgery. Results: Healing was uneventful in all patients. Significant clinical improvements were observed at 1 and 3 years postoperatively (P <0.01; probing depth averaged 4.4 ± 1.6 and 4.7 ± 1.4 mm and clinical attachment level gain was 3.9 ± 1.4 and 3.5 ± 1.3 mm, respectively). The histologic evaluation revealed formation of new cellular cementum and new periodontal ligament in four of the five cases. In general, the xenograft particles seemed to be mostly embedded in connective tissue without any evidence of new bone formation. Conclusion: GTR treatment of intrabony defects with the collagen membrane from bovine pericardium and adjunct implantation of the new bovine bone biomaterial may result in significant clinical improvements that can be maintained over a period of 3 years, and regeneration of cementum and periodontal ligament, but without bone formation.     

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.     

Adenomatoid odontogenic tumor: a report of a rare case with recurrence

Adenomatoid odontogenic tumor (AOT) is an uncommon tumor of odontogenic origin, composed of odontogenic epithelium in a variety of histoarchitectural patterns, and characterized by slow but progressive growth. Generally, recurrences seldom, if ever, occur after surgical curettage, while here we report an extremely rare case of AOT with recurrence. The patient was a 36-year-old Chinese man who presented with a palpable bony-hard swelling in the anterior maxillary region initially at the age of 16 and the lesion recurred twice over a 20-year period. The tumor was diagnosed as AOT with well-defined unilocular radiolucency shown in X-ray graphs and solid nodule of cuboidal or columnar cells of odontogenic epithelium forming typical nests or rosette-like structures as well as characteristic duct-like spaces in histologic findings.     

Evaluation of periodontal regeneration following grafting intrabony defects with bio-oss collagen: a human histologic report

This study evaluated the clinical, radiographic, and histologic response to Bio-Oss Collagen when used alone or in combination with Bio-Gide bilayer collagen membrane for the treatment of four intrabony defects (5 to 7 mm) around single-rooted teeth. After reflecting a full-thickness flap, thorough degranulation and root planing were accomplished. In all cases, Bio-Oss Collagen was then used to fill the defects, and in two cases, a Bio-Gide membrane was placed over the filled defect. Radiographs, clinical probing depths, and attachment levels were obtained before treatment and immediately preceding en bloc resection of teeth and surrounding tissues 9 months later. Reduction in pocket depth and gain in clinical attachment level were observed for both treatment protocols. The histologic evaluation demonstrated the formation of a complete new attachment apparatus, evidencing periodontal regeneration that varied with defect morphology. This human histologic study demonstrated that Bio-Oss Collagen has the capacity to induce regeneration of the periodontal attachment apparatus when placed in intrabony defects.     

Adenomatoid odontogenic tumor--a rare cause of jaw swelling

Adenomatoid odontogenic tumor (AOT) is an uncommon tumor of odontogenic origin, characterized histologically by the formation of ductlike structures with amyloid-like deposits. Histogenesis of AOT is still uncertain and it is often considered as a hamartomatous lesion rather than a true neoplasm. AOT has a benign behavior and conservative surgical enucleation or curettage is sufficient. We report a case of AOT in a 15-year-old female who presented with left-sided jaw swelling with tooth resorption. Histopathology revealed intraosseus follicular variant of AOT. A brief review of literature is also discussed.     

New periodontal attachment procedure based on retardation of epithelial migration

Abstract A new attachment procedure based on retardation of epithelial downgrowth was used for the surgical treatment of 88 intrabony periodontal defects. Split flaps were made at the vestibular and oral aspect of the intrabony defect leaving a layer of connective tissue on the bone and corresponding to the missing bony walls. Granulation tissue was removed from the defect and the root surface planed. After transplantation of autogenous cancellous bone grafts from edentulous ridges, the defect was covered with a free palatal graft which was sutured to the adjacent, attached gingiva and underlying periosteum. The grafted area was covered with telfa and Coe pack was applied for 1–2 weeks. This procedure and a modification of it resulted in a markedly greater zone of new attachment when compared with traditional flap surgery. Residual pockets deeper than 3 mm were found in only 10 per cent of the defects treated by the soft tissue grafting technique.     

Chirurgische Verlaufsbeobachtung eines adenomatoid odontogenen Tumors (AOT) im Unterkiefer: Ein Fallbericht

The AOT is a relative rare benign odontogenic tumor. It most often appears in the canine region of the maxilla and mandible in young patients. Radiolucencies in the region of non-erupted or vital teeth may produce diagnostic problems. The histological diagnosis of AOT is characterised by odontogenic epithelium, ductlike structures, amyloid-like material and calcifying areas. Case report A female patient of eleven years and ten months was referred for surgical exposure of the left mandibular canine by an orthodontist. This tooth was retained and root formation was incomplete. Radiologically, a radiolucency was seen, extending distally from the crown of the tooth towards the root. The deciduous tooth 73 was extracted and the retained left mandibular canine was surgically exposed. Healing was without result and the tooth was moved orthodontically. Two years later the tooth was seen in regular position and occlusion. Vitality tests were positive, distally to the tooth a 1.5?mm periodontal pocket was disclosed. A large radiolucency around the root of the tooth was seen. Supposing a cystic lesion a surgical intervention was performed without removal of the tooth. Histopathologically, an AOT was revealed. Conclusions In the sequence of surgical interventions it is highly likely that already at the first operation an AOT was present, however, went unnoticed clinically. The histological diagnosis of an AOT was only revealed after a second operation including tumor removal. In spite of surgical removal of the AOT the involved tooth found its position in the dental arch.     

Histologic evaluation of human intrabony defects following non-surgical periodontal therapy with and without application of an enamel matrix protein derivative

BACKGROUND: Surgical periodontal treatment with enamel matrix protein derivative (EMD) has been shown to promote periodontal regeneration. However, it is not known whether nonsurgical periodontal therapy with additional subgingival application of EMD may also enhance periodontal regeneration. The purpose of this study was to clinically and histologically evaluate healing of human intrabony defects following non-surgical periodontal treatment with and without application of EMD. METHODS: Sixteen patients, each of whom displayed one advanced intrabony defect around teeth or roots scheduled for extraction, were included in the study. The defects were treated as follows: 1) scaling and root planing with hand instruments and application of EMD; 2) scaling with an ultrasonic instrument and application of EMD; or 3) scaling with an ultrasonic instrument alone. Healing was uneventful in all cases. Six months after surgery, the teeth or roots were extracted together with some of their surrounding soft and hard tissues and processed for histologic evaluation. RESULTS: Clinical examination revealed a probing depth reduction and a gain of clinical attachment after all 3 treatment modalities. The histological evaluation, however, revealed that healing in all 3 procedures was predominantly characterized by formation of a long junctional epithelium along the instrumented root surface and no predictable regeneration of attachment apparatus. CONCLUSION: Within its limits, the present study failed to show periodontal regeneration in advanced human intrabony defects following non-surgical treatment with subgingival application of EMD.     

Adenomatoid odontogenic tumor arising from the mandibular molar region: a case report and review of the literature

This case report describes a rare case of an adenomatoid odontogenic tumor (AOT) arising in the mandibular third molar region of a 20-year-old female. The tumor was a well-circumscribed intraosseous lesion with an embedded tooth. Histologically, the induction of extensive globular calcification was evident in addition to the characteristic histological features of AOT. The present case lends support to the categorization of AOT as an odontogenic tumor consisting of a disorderly mixture of odontogenic epithelium and odontogenic ectomesenchyme with calcification.     

Human histologic evaluation of an intrabony defect treated with enamel matrix derivative, xenograft, and GTR

The purpose of the present case report is to clinically and histologically evaluate the healing of one advanced intrabony defect following treatment with an enamel matrix protein derivative (EMD) combined with a bovine-derived xenograft (BDX) and guided tissue regeneration (GTR). One patient with generalized chronic periodontitis and one advanced intrabony defect was treated with EMD + BDX + GTR. Notches were placed in the root at the level of the calculus and alveolar crest to aid histologic identification of new periodontal tissues. Postoperative healing was uneventful. At the 7-month histologic examination, healing in the intrabony component of the defect was characterized by formation of new connective tissue attachment (new cellular cementum with inserting collagen fibers) and new bone in the intrabony component. The BDX particles were surrounded by bone-like tissue. No direct contact between the graft particles and root surface (cementum or dentin) was observed. Healing in the suprabony defect component occurred through epithelial downgrowth that stopped at the level of the coronal notch. The BDX particles were entirely encapsulated in dense connective tissue, without any signs of bone formation. The present case report shows formation of new attachment apparatus consisting of new bone, cementum, and periodontal ligament in the intrabony component of one human defect treated with EMD + BDX + GTR.     

Periodontal repair in surgically created intrabony defects in dogs: influence of the number of bone walls on healing response

BACKGROUND: The objective of this study was to histologically evaluate periodontal healing following flap surgery in intrabony periodontal defects to determine the influence of the number of bone walls on periodontal regeneration. METHODS: One-, 2-, and 3-wall intrabony periodontal defects were surgically produced at the proximal aspect of mandibular premolars in either right or left jaw quadrants in six beagle dogs. Mucoperiosteal flaps were positioned and sutured to their presurgery position following defect preparation. The animals were euthanized at 8 weeks post-surgery, and block sections of the defect sites were collected for histologic and histometric analysis. RESULTS: Bone and cementum regeneration was positively correlated to the number of bone walls limiting the intrabony periodontal defects. The junctional epithelium averaged (+/- SD) 1.5 +/- 0.2, 1.2 +/- 0.3, and 0.9 +/- 0.2 mm for the 1-, 2-, and 3-wall defects, respectively, with the 3-wall defects being significantly different from the 1-wall defects (P <0.05). Cementum regeneration averaged 1.2 +/- 0.6, 2.0 +/- 0.6, and 2.8 +/- 0.5 mm for the 1-, 2-, and 3-wall defects, respectively; all groups were significantly different from each other (P <0.05). Bone regeneration averaged 1.5 +/- 0.5, 1.7 +/- 0.6, and 2.3 +/- 0.5 mm for the 1-, 2-, and 3-wall defects, respectively, with the 3-wall defects being significantly different from the 1-wall defects (P <0.05). CONCLUSIONS: The results suggest that the number of bone walls is a critical factor determining treatment outcomes in intrabony periodontal defects. One- and 3-wall intrabony defects appear to be reproducible models to evaluate candidate technologies for periodontal regeneration.     

Defect-determined regenerative options for treating periodontal intrabony defects in baboons

BACKGROUND: In an effort to regenerate periodontal intrabony defects, the healing potential of the defect should determine what therapeutic modalities and materials are employed. The purpose of this study was to compare regenerative outcomes in baboon intrabony defects that were contained versus non-contained, using various regenerative therapies. METHODS: Nine adult baboons (Papio anubis) in good health were treated. Eighty-six interproximal, intrabony defects were surgically created: 43 contained by 3 walls of bone; 43 non-contained with a missing buccal wall. Chronicity and plaque accumulation were encouraged with wire ligature placement for 8 weeks. After ligature removal, scaling, and a 2- to 4-week healing period, the defects were treated with the following therapies: collagen membrane (GTR), human demineralized freeze-dried bone (DFDB) grafting (BG), combined therapy (GTR + BG) and a DFDB-glycoprotein sponge matrix (MAT). Clinical healing responses were evaluated in 58 sites by changes in soft tissue (recession, probing, clinical attachment) and hard tissue (resorption, defect fill) parameters 6 months post-treatment. Histologic evaluation (defect regeneration, connective tissue attachment, epithelial migration) was done on 26 sites. RESULTS: For contained defects, no real significant clinical (ANOVA) or histologic differences existed among treatments. However, for non-contained defects, combined therapy (GTR + BG) demonstrated clinically significant (P < or = 0.05, ANOVA) and histologically superior healing results over the other therapies tested. CONCLUSION: These results confirm a defect morphology directed rationale for periodontal intrabony therapy.     

Two patterns of histologic healing in an intrabony defect following treatment with enamel matrix derivative: a human case report

Human histologic evidence of periodontal regeneration following treatment of intrabony defects with enamel matrix derivative has yielded inconsistent results in recent case reports. A 46-year-old woman presenting one deep intrabony defect at the distal root of a mandibular first molar scheduled for extraction was selected for enamel matrix derivative therapy. During surgery, a notch was placed at the most apical level of calculus on the experimental root. Nine months postsurgery, a block section including the distal root and surrounding periodontal tissues was obtained and processed in a mesiodistal plane. Histologic analysis demonstrated two different patterns of healing along the proximal and furcal surfaces. Regeneration with new cellular cementum, bone, and periodontal ligament with functional fiber orientation was observed on the distal aspect of the root, whereas the furcal surface healed through ankylosis. This report underlines the biologic variability in wound healing following enamel matrix derivative therapy in periodontal intrabony defects and within the same defect. Host-specific intrinsic and/or extrinsic factors accounting for this variability remain to be investigated.     

Squamous odontogenic tumor (SOT): a benign neoplasm of the periodontium

Abstract True neoplasms are rarely localised to the periodontium. However, early recognition and diagnosis of neoplastic lesions resides within the realm of responsibility of the dentist. In recent years, a number of odontogenic tumors has been described characterized by an occurrence on the gingiva or in the intrabony part of the periodontium. One such neoplasm, the squamous odontogenic tumor (SOT) originally described 20 years ago is now a well-recognized entity localized to the periodontium, be it in the periodontal ligament or in the gingivae. A review of 36 acceptable cases of this tumor published sofar, forms the basis of the present paper.     

Effects of combined treatment with porous bovine inorganic bone grafts and bilayer porcine collagen membrane on refractory one-wall intrabony defects

The aim of this study was to investigate the effects of a combination of porous bovine inorganic bone graft (Bio-Oss) and bilayer porcine collagen membrane (Bio-Gide) on refractory one-wall intrabony defects in dogs. Bio-Oss and Bio-Gide were applied into the refractory one-wall intrabony defect. The contralateral sites were used as controls (without the application of Bio-Oss and Bio-Gide). At 24 weeks after surgery, similar pocket depths were found in both groups. However, histologic observation revealed an infiltration of inflammatory cells in the control group caused by poor gingival architecture, whereas only a few of the experimental sites showed inflammatory infiltration. In addition to the healthy gingival tissue, periodontal tissue regeneration was observed in the experimental group. The combination of Bio-Oss and Bio-Gide was an effective treatment for refractory one-wall intrabony defects in dogs.     

Neoplastic potential of odontogenic cysts

Odontogenic cysts and tumors are distinct entities and quite a common occurrence in the jaw bones. The lining of odontogenic cysts shows a potential for neoplastic transformation to non odontogenic malignancies like squamous cell carcinoma and mucoepidermoid carcinoma, and odontogenic tumors like ameloblastoma and adenoamatoid odontogenic tumor (AOT). AOT is a benign, epithelial odontogenic tumor, common site being the anterior maxilla. Its origin from a dentigerous cyst and in the mandible is rare. A case of an AOT arising from a dentigerous cyst associated with an impacted permanent mandibular left lateral incisor is reported.