[Innovative methods and developments in oral care. 3D planning in oral and maxillofacial surgery]. / Serie: Innovatieve technieken en ontwikkelingen in de mondzorg. 3D-planning in de mka-chirurgie.

With the use of cone beam computed tomography, intraoral scanning and 3D stereophotogrammetry, a virtual 3D head model of a patient can be reconstructed with image fusion. In this way, the malposition, deficiency and other anomalies at the level of bone, dentition and soft tissue can be quantified objectively. The desired position of the dentition, occlusion and soft tissue in the facial profile can be virtually drawn in and used as a guideline for treatment planning. Based on the principle of backward planning, it is possible to determine what repositioning of the jaw is required, where there is a need for bone augmentation and how many dental implants are necessary to obtain the desired treatment outcome. From this perspective, 3D treatment planning has become a treatment standard for the 4 clinical pillars supporting oral and maxillofacial surgery, specifically orthognathic surgery, implantology, craniofacial surgery and head & neck oncology. 3D planning has influenced today's workflow, planning of complex surgery and contributed to useful further innovations and efficient healthcare.

The Accuracy of Maxillary Position Using a Computer-Aided Design/Computer-Aided Manufacturing Intermediate Splint Derived Via Surgical Simulation in Bimaxillary Orthognathic Surgery.

PURPOSE: The purpose of this study was to assess the clinical interventions and the accuracy of maxillary reposition using a computer-aided design/computer-aided manufacturing (CAD/CAM) splint derived via surgical simulation. MATERIALS AND METHODS: The retrospective study comprised 24 patients who underwent bimaxillary surgery. The patients were assigned to 1 of 2 groups by a way of maxillary repositioning. One group received conventional intermediate wafers and the other CAD/CAM wafers during Le Fort I osteotomy. We recorded operation time, blood loss, the operative accuracy. Accuracy was analyzed by 3-dimensional computed tomography images before and immediately after the operation. The evaluation points were the right maxillary first incisor (U1), the right maxillary second molar (M2-right), and the left maxillary second molar (M2-left). RESULTS: The 2 groups did not differ significantly in operation time and blood losses. The vertical axis of U1 data differed significantly between the 2 groups (P = 0.008). None of the horizontal, vertical, or anteroposterior axis of M2-right data differed significantly, and anteroposterior axis of M2-left data differed significantly (P = 0.0296). The CAD/CAM group 3-dimensional distance errors were less than those of the conventional group for all points. CONCLUSION: Placement of CAD/CAM splint allowed highly accurate repositioning; the accuracy exceeded that afforded by conventional model surgery using a facebow and articulator.

Retrospective 3D analysis of bone regeneration after cystectomy of odontogenic cysts.

BACKGROUND/OBJECTIVE: In this retrospective study, we aimed to investigate a new 3D evaluation method for evaluating bone regeneration after cystectomy of odontogenic cysts. METHODS: The study included 26 patients who underwent cystectomies between 2012 and 2017 and had received either fillings or non-fillings with autologous iliac crest. Bony regeneration was analyzed using 3D imaging software and comparing identical regions of interest (ROIs) that were determined by exact overlays of the postoperative cone beam computer tomography (CBCT) or computer tomography (CT) images. Outcome measures, including volume changes according to the defect size and configuration, patient age, the entity and distribution of the cysts, were collected. RESULTS: Twenty-six patients (5 women and 21 men) had 30 defects, including nine keratocysts, seven radicular cysts and 14 dentigerous cysts. A total of 73% of the defects were in the mandible. The mean 3D follow-up time was 12 months. According to the 3D evaluation of bony regeneration, the defect size and configuration showed no significant differences between the groups (filled or non-filled with 15 defects per group). CONCLUSIONS: By establishing a standardized 3D method for evaluating bone regeneration, healing can be better monitored and evaluated.

Idiopathic osteosclerosis in the maxillomandibular area.

OBJECTIVES: To test a more complete set of morphometric radiographic parameters to evaluate the idiopathic osteosclerosis (IO) lesions located in the maxillomandibular area and to know their features during routine radiographic evaluation. MATERIALS AND METHODS: Radiographs from patients attending the oral diagnosis clinic of our institution were reviewed. Evaluated parameters were gender and age of the patients, size, side, homogeneity, morphology, radiodensity, mineralization, borders, relation to roots, affected tooth or teeth and location of the analyzed lesions. RESULTS: Of the 6340 assessed patients, 354 (5.6%) harbored 362 lesions. IOs were more common during 2nd to 4th decades (mean age = 39 years). IO frequency rose from 1st to 3rd decades and then decreased. Size varied from 0.1 to 5.8 cm, and its frequency increased from 7 to 30 years age and then decreased too. The mandible and molar region were more commonly affected. Radiopaque image, radicular location, round shape, homogeneous core and well-defined boundaries were the more frequent IO features. CONCLUSIONS: Our method allows to analyze IO lesions with precise parameters. Analysis of the results does not support the previously suggested theories to explain their origin, and these figures suggest that the so-called IOs are developmental alterations of the bone.

Mandibular Implant-Retained Overdentures: Potential Accelerator of Bone Loss in the Anterior Maxilla?

PURPOSE: To compare the residual ridge resorption (RRR) of the anterior maxillary bone beneath complete dentures when opposed by mandibular complete dentures (CD) and implant-retained overdentures (IRO). MATERIALS AND METHODS: 18 patients were rehabilitated with maxillary CD opposing mandibular IRO, and 4 patients were prescribed with conventional CD. Cone beam computed tomography (CBCT) scans of the maxilla were acquired before and 1 year post-treatment and converted into 3D models using Mimics research software. RRR was quantified by measuring the changes in bone volume following superimpositioning and sectioning of these models at the anterior maxillary region. Subsequently, the sectioned 3D models of the anterior maxilla were exported to 3-Matic software to reveal the predominant region and depth of RRR. RESULTS: The mean reduction in bone volume of the anterior maxilla in the CD group was 2.60% (SD = 1.71%, range = -4.89 % to -0.92%, median = -2.30%), while the mean reduction in the IRO group was almost three times higher at 7.25% (SD = 3.16%, range = -13.25 to -1.50, median = -7.15%). The predominant areas of RRR were on the buccal and occlusal ridge of the anterior maxilla. CONCLUSION: Within the limits of this study, it may be concluded that an IRO caused significantly higher RRR of the anterior maxilla than a CD.

Glandular odontogenic cyst: An updated analysis of 169 cases reported in the literature.

OBJECTIVE: To integrate the available data published on glandular odontogenic cyst (GOC) into a comprehensive analysis of its clinical/radiological and histopathological features. METHODS: An electronic search was undertaken in May/2017. Eligibility criteria included publications having enough clinical/radiological/histological information to confirm the diagnosis. RESULTS: Fifty-eight publications (169 GOCs) were included. The lesion was slightly more prevalent in men than in women. There was a high prevalence in the fifty/sixth decades of life, in the anterior regions, and in mandibles. Lesions were commonly associated with bone expansion (73%) and unilocular radiological appearance (61.5%). GOC was found to be associated with tooth displacement or an unerupted tooth (30.9%), cortical bone perforation (26%), presence of clinical symptoms (24.3%), root resorption (13.9%). Microscopic parameters most commonly were observed in GOCs-in at least 95% of the lesions: presence of hobnail cells, intraepithelial microcysts, epithelial lining with variable thickness. The presence of apocrine snouting was the microscopic parameter less often found (40.4%). CONCLUSION: Although the recurrence rate of GOCs is not as high as previously believed, it is a relevant phenomenon (21.6%). Adjunctive procedures after enucleation should be considered. None of the clinical/radiological and histopathological features evaluated had a statistically significant effect on the recurrence rate.

Plasma Cell Granuloma of the Jaw and the Infratemporal Fossa: A Clinical Case.

Plasma cell granuloma or inflammatory pseudotumor (IPT) is diagnosed by a process of elimination. The precise etiology is unknown, although it can occur after a bout of periodontal infection. This report describes the various stages of progression for this ailment. A 49-year-old woman with no noteworthy medical history presented with a recurrent periodontal abscess accompanied by progressive and severe destruction of the right maxilla. There was invasion of the infratemporal fossa and very tight trismus. Histologic examination indicated a reactive plasma cell granuloma. IPT is an entity recognized by the World Health Organization. A triggering infectious or inflammatory factor is often present. In the maxilla, progression is very aggressive. Treatment relies on corticotherapy, with or without radiotherapy, and administration of cyclosporine.

Methotrexate-Related Lymphoproliferative Disorder in Patients With Osteonecrosis of the Jaw: A 3-Case Report and Literature Review.

Patients with immunodeficiency or immunosuppression are at risk of developing a lymphoproliferative disorder (LPD). Methotrexate (MTX) is an iatrogenic cause of LPD, which in up to 50% cases occurs in extranodal sites. The occurrence of MTX-related LPD with osteonecrosis of the jaw (ONJ) has rarely been reported. Moreover, there are no clear diagnostic criteria and treatment strategies for management of these lesions. In the present cases, discontinuing MTX and debridement of the necrotic bone were effective. This report describes 3 cases of MTX-related LPD in patients with longstanding rheumatoid arthritis (RA) who presented with ONJ. The first patient was a 74-year-old man with RA who had received treatment with MTX for 7 years before presenting with ONJ and submental lymphadenopathy. The second patient was a 79-year-old woman who had been treated for 21 years with MTX and who presented with ONJ. The third patient was a 67-year-old man who had been treated with MTX for more than 15 years. In all 3 cases, biopsy, histology, and immunohistochemistry using a panel of lymphoid markers (Epstein-Barr virus [EBV], CD79a, CD20, PAX-5, CD3, and CD30) resulted in the diagnosis of EBV-driven T-cell, B-cell, and Hodgkin-like LPD. All 3 patients recovered after cessation of MTX and surgical debridement. Biopsy examination, diagnostic immunohistochemistry using lymphoid immune markers, and imaging studies using computed tomography, magnetic resonance imaging, and positron-emission tomographic computed tomography were useful for the correct diagnosis of this condition.

Infraorbital Nerve Located Medially to Postoperative Maxillary Cysts: A Risk of Endonasal Surgery.

BACKGROUND/AIMS: This study aimed to examine variations in the location of the infraorbital nerve relative to postoperative maxillary cysts to assess the potential risk of nerve injury during endonasal marsupialization. METHODS: Coronal computed tomography images of 130 patients (162 sides) with postoperative maxillary cysts who visited our clinic between 2003 and 2014 were reviewed from the viewpoint of the anatomical relationship between the infraorbital nerves and cysts. RESULTS: The proportions of the six locations were as follows: upside 45.1% (n = 73), separate 13.0% (n = 21), medial 5.6% (n = 9), lateral 14.2% (n = 23), in-between 7.4% (n = 12), and unevaluable 14.8% (n = 24). The proportion of the cases with a potential risk of infraorbital nerve damage during endoscopic marsupialization, including medial, in-between, and unevaluable locations, was 27.8%. Retrospective chart review revealed that 2 patients with a postoperative maxillary cyst that were unevaluable complained of persistent postoperative hypoesthesia of the cheek. CONCLUSION: The anatomical relationship between the infraorbital nerve and postoperative maxillary cysts varied among patients, with approximately one-fourth of the patients being at risk of infraorbital nerve injury even during endoscopic procedures.

Odontogenic Keratocysts as First Manifestation of Nevoid Basal Cell Carcinoma Syndrome: Surgical Management and Immunohistochemical Analysis.

Nevoid Basal Cell Carcinoma Syndrome (NBCCS), also known as Gorlin syndrome, is a rare autosomal dominant disorder, with no gender predilection. Individuals with NBCCS are commonly diagnosed between 17 and 35 years old and can present multiple basal cell carcinomas scattered throughout the body, presence of recurrent and early-onset odontogenic keratocysts (OKCs) and skeletal abnormalities. This article describes a case of a 13-year-old white boy who referred complaining of facial asymmetry. Extraoral examination revealed volumetric increase displacing the nasal ala from the right side and extended to the zygomatic bone. The intraoral evaluation showed mixed dentition with moderate degree of malocclusion. In addition, bilateral vestibular fornix swelling was observed in the upper canine region. An increase in volume was also detected on the hard palate on the right side. Computed tomography revealed multiple hypodense lesions with cystic appearance. The aspiration was positive, with a yellowish aspirate of serous consistency of all lesions. Given the numerous lesions, it was decided to decompress them for posterior enucleation procedures. In addition to other manifestations, the patient was diagnosed with NBCCS. Although common, the occurrence of OKCs in pediatric patients, especially in multiple lesions, is highly indicative of NBCCS, and its investigation should be considered, even in the absence of other signs of this syndrome. Synchronous decompression was satisfactory and can be used in similar cases of multiple cystic lesions.

Novel Technique for Reconstruction of the Severely Resorbed Posterior Maxillae: Tuberosity-Flip Approach.

PURPOSE: This report describes a novel technique that allows for 3-dimensional augmentation of localized bone defects of the posterior maxilla and simultaneous implant placement by means of using the maxillary tuberosity as a block graft. MATERIALS AND METHODS: The residual bone in maxillary tuberosity is harvested as a whole. The recipient site and the bone graft are prepared with compatible implant drills. The bone graft is flipped to fit the defect and fixated in place using the dental implant, which anchors both the graft and the subantral bone. RESULTS: The defect of the posterior maxilla is reconstructed with autogenous bone harvested from maxillary tuberosity, and simultaneous implant placement is achieved. CONCLUSION: The proposed technique enables the clinician to reconstruct alveolar defects of the posterior maxilla without the need for an additional donor site and simultaneously place dental implants.

Concomitant Temporomandibular Joint Ankylosis and Maxillomandibular Fusion in a Child with Klippel- Feil Syndrome: A Case Report.

Klippel-Feil syndrome (KFS) is classically characterized by fusion of any of the two of seven cervical vertebrae. It is identified by the presence of a triad of clinical signs including short neck, limitation of head and neck movements and low posterior hairline. Unusual bony malformations leading to facial asymmetry is the most common oral manifestation associated with KFS. Such maxillomandibular fusion can also result in restricted mouth opening in children. It's a challenge to provide complete rehabilitation in such children. This paper presents a report of a type II KFS with both maxillomandibular fusion and temporomandibular joint ankylosis which led to the limited mouth opening in a six-year-old child. Also, the child showed an inadequate development of speech, facial asymmetry and compromised oral health owing to the restricted mouth opening. After thorough investigations, surgery was done which restored limited mouth opening which led to normalizing of speech and oral health.

Cholesterol granuloma of the maxilla.

Intra-osseous cholesterol granuloma (CG) is a rare and benign lesion. Very few cases of CG of the jaws have been described in the literature. CG of the jaws seems to be due to the accumulation of cholesterol of hematogenous origin in odontogenic cysts. We report on one case of CG of the maxilla treated by surgical enucleation in a 46-year-old man who presented an asymptomatic swelling of the maxilla.

A principal components analysis: how pneumatization and edentulism contribute to maxillary atrophy.

OBJECTIVE: The aim of this retrospective cohort study was to investigate the role of sinus pneumatization and residual ridge resorption in maxillary bone loss in 400 computed tomography (CT) scans. MATERIALS AND METHODS: In 200 dentate and 200 edentulous patients, both sinuses were analysed using CT scans. The image analysis sequence consisted of manual placement of 24 reference points, followed by automated segmentation and final manual refinement. Finally, a principal components analysis was performed. RESULTS: A total of 788 sinuses were included into the analysis. The edentulous group (98 female: 67.77 ± 11.28 years, 99 male: 65.22 ± 9.87) was significantly older than the group with teeth (99 female: 46.89 ± 16.77 years, 96 male: 49.74 ± 16.2). Female and male patients did not differ regarding age. The alveolar height differed significantly between the groups (edentulous: 7.1 ± 4.3 mm, with teeth: 9.7 ± 4.1 mm), but not between gender (female: 8.3 ± 4.4 mm, male: 8.5 ± 4.4 mm). Principal components analysis was able to explain 90% of the variation in sinus morphology. CONCLUSIONS: Prolonged edentulism in the maxillary molar region leads to centripetal and to minor degrees centrifugal ridge resorption. Minor pneumatization occurs in the sinus walls, but the sinus depth underlies the anatomical variation independent of dentition.

Management of Large Maxillomandibular Osteofibrous Dysplasia as Part of a Humanitarian Mission.

PURPOSE: Maxillomandibular ossifying fibroma is a benign tumor that affects young adults. Complete excision can allow satisfactory management with no recurrence. During a humanitarian mission, one is confronted with many types of damage from these fibromas. Their management requires wide resection (mandibulectomy interrupter or maxillectomy) and free flap reconstruction. However, technical conditions during a humanitarian mission might not allow the performance of a free flap reconstruction. How can such patients be managed? Should these patients receive a straightforward intervention performed on site during the mission or should they go to another country with a technical platform suitable for microsurgical reconstruction? PATIENTS AND METHODS: During a humanitarian mission in Ouagadougou, Burkina Faso, 6 patients with large ossifying fibromas traveled to France to undergo wide excision of the lesion and free flap reconstruction using the fibula. The Enfants du Noma paid for the travel and medical costs. RESULTS: No flap was lost. Four patients (67%) had local (disunity of scar or local infection) or general (malaria) complications that quickly resolved. CONCLUSIONS: Most teams agree that free flaps should not be performed during humanitarian missions, and only 1 German team practices in Sokoto, Nigeria. Therefore, medical travel is an attractive solution that allows optimal management and requires financial assistance from humanitarian organizations.

Large Dentigerous Cyst Associated to Maxillary Canine.

Dentigerous cysts are defined as a cyst originated by separation of the follicle of dental crown of a tooth unerupted. Although most dentigerous cysts are considered developmental cysts, some cases seem to have an inflammatory origin. The aim of this study was to show a case of an 8-year-old patient, male, presenting a lesion in maxilla with large proportions. Computed tomography scans showed a hypodense image, well-defined, associated to unerupted teeth. The case was treated by enucleation of the lesion under local anesthesia. Histopathological examination confirmed the diagnostic suspicious of dentigerous cyst. Currently, 3-year follow-up period showed no signs of recurrence, and it was observed eruption of the teeth associated to the lesion. This case highlights the importance of the association between clinical and radiographic analysis together to the surgical findings, aiming the best treatment for the patient.

A Case of Pentastomiasis at the Left Maxilla Bone in a Patient with Thyroid Cancer.

Pentastomiasis, a zoonotic parasite infection, is typically found in the respiratory tract and viscera of the host, including humans. Here, we report for the first time an extremely rare case of intraosseous pentastomiasis in the human maxilla suffering from medication related osteonecrosis of the jaw (MRONJ). A 55-year-old male had continuously visited the hospital for MRONJ which had primarily developed after bisphosphonate and anti-neoplastic administration for previous bone metastasis of medullary thyroid cancer. Pain, bone exposure, and pus discharge in the right mandible and left maxilla were seen. Osteolysis with maxillary cortical bone perforation at the left buccal vestibule, palate, nasal cavity, and maxillary sinus was observed by radiologic images. A biopsy was done at the left maxilla and through pathological evaluation, a parasite with features of pentastome was revealed within the necrotic bone tissue. Further history taking and laboratory evaluation was done. The parasite was suspected to be infected through maxillary open wounds caused by MRONJ. Awareness of intraosseous pentastomiasis should be emphasized not to be missed behind the MRONJ. Proper evaluation and interpretation for past medical history may lead to correct differential diagnosis and therapeutic intervention for parasite infections.

The Value of Cone Beam Computed Tomography in the Management of Dentigerous Cysts ­ A Review and Case Report.

Cone Beam Computed Tomography (CBCT) has recently seen an expansion in use, however there are few robust, evidence-based guidelines to inform practitioners. This article reports the case of a large dentigerous cyst in the maxilla affecting the eruption of multiple teeth, considers the use of CBCT in the management of such lesions, and discusses guidelines on the use of CBCT in dentistry. Clinical relevance: As CBCT use increases it is important that practitioners understand the guidelines surrounding its use. Due to the prevalence of dentigerous cysts, it is likely that they will be encountered clinically, and it is important that clinicians referring patients with such lesions are familiar with the principles of managing them.

Classification of alveolar bone destruction patterns on maxillary molars by using cone-beam computed tomography.

OBJECTIVE: The defective diagnosis of alveolar structures is one of most serious handicaps when assessing available periodontal treatment options for the prevention of tooth loss. The aim of this research was to classify alveolar bone defects in the maxillary molar region which is a challenging area for dental implant applications. To our knowledge, this is the first study of periodontal bone defect prevalence by using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: In this study, the remaining alveolar bone patterns of 669 maxillary molars of 243 patients with periodontal bone loss were investigated on four aspects and the furcation areas of teeth, and then they were classified into six main groups. Combined periodontal-endodontic lesions (CPELs) were also reported in another category. RESULTS: Following exclusion of 39 (5.8%) teeth with CPEL, the most common group was horizontal bone defects (71.4%) and the least seen group was three-walled vertical bone defects (1.9%) in all alveolar bone sides of teeth. Osseous crater was found at the rate of 6.7% on interdental alveolar bone. Dehiscence and fenestration were detected at rates of 2.7% and 3.3%, respectively. In the assessment of furcation areas, there was no furcation involvement in 61.4% of all teeth and the rate of Grade-II involvements was 26.2%. CONCLUSIONS: The most appropriate treatment option may be decided through accurate imaging of periodontal defect morphology. CBCT can provide comprehensive information about the remaining alveolar bone structures. In this way, the need for dental implant can be prevented in many cases and be replaced with a more conservative approach on the maxillary molar region.

Implant-supported single-tooth restorations. A 12-year prospective study.

OBJECTIVE: The aim of this study was to evaluate prospectively the 12-year outcome of implant-supported single-tooth restorations. MATERIAL AND METHODS: Originally 45 self-tapping Astra Tech TiOblast® ST-implants were installed by a two-stage protocol in 40 subjects requiring single-tooth prosthetic replacement for a missing tooth. Clinical and radiologic examinations were performed at completion of the prosthetic treatment 4-7 months after implant installation surgery and after 5 and 12 years in function. RESULTS: At 12 years 31 patients and 35 implants were available for evaluation. The overall failure rate after 12 years was 10.3% on the subject level and 9.1% on the implant level. The mean bone loss amounted to 0.67 mm (SD 2.20) on a subject level and 0.47 mm (1.72) on an implant level. Three subjects (10%) and three implants (8.6%) were diagnosed with peri-implantitis. Five subjects had experienced technical complications; three incidences of loosening of the abutment retention screw during the first 5 years and two minor porcelain fracture of the crown (two patients) between 5- and 12-years of follow-up. CONCLUSION: The findings reported in this 12-year prospective case series suggest that the use of the Astra Tech dental implants may be a valid treatment alternative for single-tooth replacement prostheses.