Sinus presurgical evaluation: a literature review and a new classification proposal

INTRODUCTION

Presurgical evaluation with cone beam computed tomography (CBCT) or computed tomography (CT) has become an essential tool for diagnosis and surgical planning, including maxillary sinus floor elevation. Before performing a sinus lift, the clinician's attention should not be only directed to the patency of the ostium through CBCT or CT, because many anatomical features could influence the surgical approach of sinus floor elevation. The goal of this article was to facilitate the communication between clinicians regarding the type of maxillary sinus, encourage in-depth analysis prior to surgery and reduce the risk of complications due to possible underestimation of important parameters.

EVIDENCE ACQUISITION

An electronic search was conducted in Pubmed, Embase, Medline and Scopus, matching the following keywords: "sinus lift", "CBCT", "CT", "presurgical" and "evaluation". Clinical Oral Implant Research, Implant Dentistry, International Journal of Periodontics and Restorative Dentistry and Journal of Oral Implantology were hand-searched. The bibliographies of review articles were checked and personal references were also searched.

EVIDENCE SYNTHESIS

Eleven parameters, that clinicians must check every time through CBCT or CT, were evaluated from different studies. At the end of the literature review for every single feature, the Authors established a favorable, a normal and an unfavorable situation, in order to provide a new classification.

CONCLUSIONS

The grade of the described classification may be useful for clinicians to understand what probably the risk level of the sinus lift surgery could be and it may encourage the surgeon to have a careful pre-operative evaluation through CBCT or CT.

CBCT evaluation of the tridimensional relationship between impacted lower third molar and the inferior alveolar nerve position

BACKGROUND

The aim of this study is to evaluate if the statistical significant relations between the measures taken exists or not and to show how the 3D reconstruction could be help the oral surgeon in all those instances in which it may have a direct impact on the planning of the surgical steps.

METHODS

Thanks to use of NobelClinician™ Software it was possible to analyze 200 mandibular tomography computerized, random selected, and create a 3D reconstruction of mandibular bone, point out dental structure of wisdom tooth and the way of IAN. Statistical analysis was performed using the Statistical Package for Social Sciences. One way ANOVA test was used to measure the association between each independent variable and the outcome variable, followed by the post-hoc least significant difference (LSD) test for intergroup differences.

RESULTS

Two independent variables were significant predictors for risk to have the distance 0 mm from IAN to apex: "Ramus relationship/space available" and "depth".

CONCLUSIONS

The 3D reconstruction software provide surgeons with an additional planning tool, offering: immediate and neat visualization of the noble structures that have to be respected and their localization in the three spatial planes; the exact morphology of the relevant root apex; a 360° view of the relationship between the IAN and the third molar and the exact point in which the root is in relationship with the canal.

Aneurismal bone cyst: a conservative surgical technique. A case report treated with a small access osteotomy

BACKGROUND

Aneurismal bone cysts (ABCs) are benign, non-neoplastic, expansive, and locally destructive lesions that may occur rarely. They are well defined and usually occur in the long bones, pelvis and vertebrae. According to the 2005 World Health Organization (WHO) histological classification of odontogenic tumours, ABC is classified as a bone-related lesion as ossyfing fibroma, fibrous dysplasia, osseous dysplasia, central giant cell lesion (granuloma-CGCL), cherubism and simple bone cyst (SBC). ABCs, as CGCLs and SBCs may arise as a consequence of an earlier trauma causing an overflow of blood into the bone, though a number of pathogenic theories have been put forward. The aim of this study is to present an unusual case of aneurismal bone cyst and to compare the different possibilities of surgical treatment after review of the literature.

CASE REPORT

ABC was localised in the posterior right region of the mandible in an 11-year-old boy, and removed by a surgical procedure involving a small access osteotomy of the mandibular ramus with removal of the cortical bone in order to enucleate the whole lesion, the wisdom tooth and to preserve the healthy bone.

Crestal sinus lift by using a mini-invasive procedure: a case series

BACKGROUND

The aim of this study was to present a case series treated with an atraumatic procedure for maxillary sinus lift by crestal approach. This technique avoids the use of classical osteotomes, thus decreasing complications due to percussive and vibratory forces.

METHODS

Three cases of partial edentulism in the distal maxillae with inadequate bone volume are treated by using SinCrest procedure (Meta, Reggio Emilia, Italy). With the guide of surgical templates, the sinus lift was performed, and implants were placed during the same procedure. After 6 months an X-ray was taken to check the success of the operation.

RESULTS

SinCrest allows the operator to advance progressively, maintaining the correct axis for implant placement. The plane tip of drills prevents accidental perforations of Schneiderian mucose, and the stops, available in different lengths, avoid the overtreatment. The manual screwing of SinCrest osteotome ensures precision during the cortical approach, while the built-in probe allows to check residual strength of sinusal floor, making sure that the Schneiderian mucose is reached and lifted. This technique does not depend on the operator's skills and decreases the onset of adverse effects due to the hammering with classical osteotomes. SinCrest requires a small flap and osteotomy, which means less healing time and more comfort for the patient, both during and after the surgery.

CONCLUSIONS

SinCrest is a valid alternative to other mini-invasive procedures for sinus lift in cases with a residual height bone of at least 5 mm, allowing an atraumatic, safe and controlled operation.

Large buccal bifurcation cyst in a child: a case report and literature review

BACKGROUND

WHO defines the mandibular buccal bifurcation cyst as a cyst occurring near the cervical margin of the lateral aspect of a root as a consequence of inflammatory process in a periodontal pocket. The pathogenesis of these cysts is still debated, but they are most likely originated from reduced enamel epithelium or from inflammatory proliferation of epithelial cell rests of Malassez that come from the superficial mucosa of a tooth in eruption. The aim of this article was to describe a case of large buccal bifurcation cyst of a permanent mandibular first molar.

CASE REPORT

A 6-year-old boy was referred to Department of Oral Riabilitation of the Istituto Stomatologico Italiano, University of Milan, Italy, with the complaint of hard swelling over the buccal gingiva and a deep probing depth located on the buccal aspect. Radiograph revealed a well-defined semilunar-shaped radiolucency, marked by a fine radiopaque line on the buccal aspect of the partially-erupted lower right first molar and it was large enough to include a small part of the crown of the second right molar. As reported in the literature the treatment of choice is enucleation and curettage of the lesion without extraction of the vital involved tooth. This procedure has shown excellent results in both the short- and long-term. The definitive diagnosis of paradental cysts can be assessed by histopathologic analysis.

Juvenile paradental cyst: presentation of a rare case involving second molar

The aim of this article was to describe a rare case of paradental cyst of the permanent mandibular second molar. A 14-year-old girl was referred to Oral Surgery Department, Dental Clinic, IRCSS Fondazione Ca' Granda, University of Milan, Italy, for the evaluation of the deep probing located on the buccal aspect of her erupted mandibular left second molar. Clinical signs of inflammation were absent and the mucosa around the second molar appeared clinically normal. Pulp tests for the second molar were positive. The evaluation of the panoramic radiograph did not revealed radiolucency. The Cone-beam tomography showed a well-defined semilunar-shaped radiolucency demarcated by a fine radiopaque line. The cyst was enucleated. The histopathologic analisys revealed the presence of hyperplastic, non-keratinized squamous epithelium with heavy, dense inflammatory cell infiltrate in the epitelium and connective tissue wall. This analysis associated with macroscopic, clinical and radiografic examination confirmed the diagnosis of paradental cyst. A clinic-pathologic correlation, incorporating the surgical, radiographic and histologic findings, is required to obtain the final diagnosis of paradental cyst. Today, the treatment of choice is simple enucleation and thorough curettage of the cyst without extraction of the involved tooth, but if CT demonstrates erosions in the buccal or lingual cortices, marsupialization should be the treatment of choice.

Treatment of seriously compromised teeth: decision- making criteria and treatment options

The aim of this article was to describe the case of a patient who presented to our attention with severe periodontal disease, complicated by furcation involvement on elements 16 and 17. In addition, the radiographic exam revealed the presence of a deep intrabony defect distal to tooth 15. Surgical therapy is performed after the resolution of the endodontic component of the intra-bony defect on the element 15 and consists on osteoplasty and ostectomy on 16, guided tissue regeneration (GTR) on 15, extraction of 17 and bi-laminar connective tissue graft for the coverage of the recession on tooth 13. The patient is visited monthly and 9 months after surgery, the definitive metal-ceramic crown is delivered and adapted to tooth 16. At 18 months, the patient's periodontal situation is re-evaluated and the pocket depth results healthy (probing depth of tooth 15=2 mm). The surgical practices reported in this work allowed for functional and esthetic rehabilitation of periodontally compromised teeth. The RSR and the GTR represent conservative surgery that allow the preservation of compromised dental elements and if properly performed, guarantee excellent survival rates of the elements in the arch. For these reasons, when it is possible, the RSR and the GTR are a valid alternative to implantology and are to be considered as the first therapeutic option in the treatment plan.

Behavior of endosseous one-piece yttrium stabilized zirconia dental implants placed in posterior areas

AIM

Considering that zirconia dental implants are indicated for the rehabilitation of highly esthetic areas, the aim of this work was to investigate the functional behavior of these implants positioned in the posterior regions of the jaws.

METHODS

The study included 6 patients with 14 zirconia implants positioned in posterior (molar) areas of the jaws. Immediately after surgery, all implants were restored with temporary crowns or bridges. Clinical radiographic evaluation was performed 6 months after surgery and subsequently every year. At these follow-up visits, periodontal indexes were recorded and peri-apical radiographs were taken in order to calculate marginal bone loss.

RESULTS

The success and survival rates were 100%. The modified bleeding index (mBI) and modified plaque index (mPLI) were respectively equal to 0.57±0.51 and 0.29 ± 0.47 at 4-year follow-up. The overall mean probing depth of the implants was 3.13±0.87 mm. The mean marginal bone loss was +0.665 mm 4 years after surgery.

CONCLUSION

Considering the limits of our study, as regards to the data concerning peri-implant tissue health, marginal bone loss and survival and success rates of zirconium implants placed in posterior areas, we can conclude that the data reported are very encouraging although the number of implants observed is still limited.

Paradental cyst of the first molar: Report of a rare case with bilateral presentation and review of the literature

The paradental cyst is a lesion classified and recognized by World Health Organization quite recently, which is related to an inflammatory process, especially pericoronitis, involving a tooth in eruption. The aim of this article is to report a rare bilateral case of paradental cyst. An 8-year-old boy presented to the Oral Surgery Department, Dental Clinic, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Fondazione Ospedale Maggiore Policlinico, University of Milan, with the complaint of swelling over the buccal gingiva of his unerupted lower left first molar. Radiographs revealed a radiolucency involving the bifurcation and root area of teeth 36 and 46. The cysts were enucleated, maintaining the affected teeth in site; microscopic evaluation revealed a chronically inflamed cyst lined by a non-keratinized stratified squamous epithelium; the histopathology associated with macroscopic and radiographic examinations permitted the definitive diagnosis of a paradental cyst on the mandibular left and right first molars. The most recent literature shows the rarity of the paradental cyst occurring with bilateral localization. Because the paradental cyst can present variable clinical and radiographic signs, it is mandatory to correlate all clinical, radiographic, and histological data to obtain a definitive diagnosis.

Minimally invasive surgical approach in a large mandibular solitary cyst: case report and review of the literature

Solitary bone cyst (SBC) is an intraosseus radiolucent lesions that defers from real cysts for the fact that peripheral epithelial lining is totally absent. It could be classified as a psudocyst and occurs most frequently in young patients. In most cases SBC doesn't cause symptoms and it is often diagnosed accidentally during routine radiographic examination. A right diagnosis of this disease is also complicated because there are no pathognomonic radiographic signs and symptoms: so this form of pseudocyst is often misdiagnosed as a common odontogenic cyst. Despite numerous studies, the pathogenesis of the SBC is not yet established: the most widely accepted theory is that it could be the result of an intramedullary necrosis determined by a trauma. In this article we report a case of SBC in child treated with a minimal surgical approach. This new kind of treatment is much more conservative than the traditional one, it can be performed as outpatients, under local anesthesia and with few postoperative discomfort: For these reasons this minimal invasive technique appears to be particulary suitable for pediatric patients.

Use of fresh frozen bone graft in rehabilitation of maxillar atrophy

AIM

Fresh frozen bone (FFB) is homologous bone obtained from human donors, provided by Tissue Banks. It is a graft material in reconstructive surgery; it is currently and widely used in orthopedic surgery and lately it has been introduced in oral and maxillofacial surgery. The purpose of this work was to show the use of fresh frozen homologous bone for bony augmentation of the maxilla and mandible in preparation for dental reconstruction with endosseous implants, as an effective alternative to harvesting and grafting autogenous bone from intra- or extra-oral donor sites.

METHODS

The case presented clinically demonstrates the use of FFB grafts in the vertical augmentation of a severe maxillary atrophy in general anesthesia, and the outpatient treatment with implants insertion and prosthetic restoration. Histologic evaluation of graft biopsy six months after surgery is added to clinical assessments.

RESULTS

Clinical outcome is shown with good volumetric and morphological reconstruction of the alveolar ridge without the need of a donor site. Excellent graft integration and bleeding newly formed bone was seen at the second surgical step (six months after FFB grafting), when fixation screws were removed and implant placement procedure was performed.

CONCLUSION

The use of FFB in major preprosthetic surgery may be an acceptable therapeutic alternative to the autogenous block graft (harvested from iliac crest or calvarium) for its success rate as graft material. Benefits include: surgical procedure with reduced discomfort and infection risk as a second operation field to harvest the graft is avoided; FFB is safe, cheap and available in programmed amounts, its use can significantly reduce operating time.

Combined treatment of odontogenic keratocysts: initial marsupialization and successive enucleation with peripheral ostectomy plus Carnoy's solution application. A five-year follow-up experience

AIM

The odontogenic keratocyst (KCOT) is a locally aggressive, cystic jaw lesion with a high growth potential and a propensity for recurrence. Considering its neoplastic features, treatments of keratocysts are required and they are generally classified as conservative or aggressive. However, although in literature there are several studies, the choice of treatment strategies remains controversial. We report a two-stage protocol based on initial marsupialization and successive enucleation.

METHODS

Three cases of large KCOTs have been treated by initial marsupialization and, after a mean period of six months, successive enucleation with peripheral ostectomy and application of Carnoy's solution was performed.

RESULTS

All patients were instructed in daily irrigation using chlorhexidine 0.2% during the period of marsupialization. After enucleation, good healing was obtained in all cases and from two up to five years of follow-up, there is no evidence of recurrence.

CONCLUSION

Two-stage surgical treatment protocol of keratocyst leads to complete healing, preservation of important anatomical structures and absence of recurrence.

Edentulous jaws rehabilitation with yttrium-stabilized zirconium dioxide implants: two years follow-up experience

AIM

The aim of this study was to present authors' two-year clinical experience with Yttrium-stabilized zirconium dioxide implants placed in native bone or regenerated bone.

METHODS

Yttrium-stabilized zirconium dioxide implants made of brezirkon (whiteSKY, Bredent medical, Senden, Germany) were used for the treatment of edentulous ridge rehabilitation in the Dental Clinic of the University of Milan (Head of the Department, Prof. F. Santoro). Zirconium dioxide is a highly resistant ceramic material obtained by cleaning zirconium dioxide and zirconium silicate. The implant used in the clinical study featured a conical one piece implant with double cylindrical thread with a sandblasted rough surface. The prosthetic section was smooth.

RESULTS

Forty-six implants have been inserted in 18 patients from January 2007 to January 2009, the follow-up period was comprised between 6 and 24 months. The overall success rate was 89%; the success rate in native bone was 97% and 74% in augmented bone. It can be stated that the success rate is comparable to titanium fixtures.

CONCLUSION

It would be logical to use a ceramic material for the esthetic regions; zirconium dioxide is particularly suitable since it features tissue friendliness and resistance comparable to titanium. The good mechanical properties, possibility of easy fabrication of the prosthetic restoration and the good integration into the tissue and the esthetics provide perfect preconditions for yttrium-stabilized zirconium dioxide to become the most commonly used material in implant dentistry.

Paradental cyst of the first molar: a report of two cases

OBJECTIVE

The paradental cyst is an uncommon lesion associated with the permanent mandibular first or second molar in children just prior to tooth eruption. The purpose of this article is to present two cases of paradental cyst affecting the buccal aspect of permanent mandibular first molar of both young patients. We also discuss diagnosis, treatment and radiographic findings of the cases.

PATIENTS AND METHODS

In both cases was made only the enucleation of cyst without extraction of the adjacent tooth. Lesional samples were sent for histopathologic analysis.

RESULTS

The histopathologic analysis of both cases, revealed a lining of hyperplastic, nonkeratinized squamous epithelium with heavy, dense inflammatory cell infiltrate in the epithelium and connective tissue wall. The histopathology associated with macroscopic and radiographic examination permitted the definitive diagnosis of a paradental cyst on the mandibular left first molar. A follow-up of 1 year was carried out in both cases and no recurrences was noted; in the first case was observed the correct eruption of the mandibular permanent left first molar.

CONCLUSIONS

A clinicopathologic correlation, incorporating the surgical, radiographic, and histological finding, is required to obtain the final diagnosis of paradental cyst. Today, the treatment of choice is simple enucleation and thorough curettage of the cyst without extraction of the involved tooth.