Masseter muscle adaptation following orthognathic surgery - Biomodelling analysis - A pilot study

Purpose: This pilot investigation was designed to apply several, newly developed and more sophisticated methods of measuring muscle structure, function and fibre orientation to a situation where adaptation of muscle is pivotal to the success of a therapeutic approach. Materials and Methods: Patients attending the combined orthodontic / orthognathic surgery clinic at the Clitrofa – Centro Médico, Dentário e Cirúrgico, in Trofa - Portugal were screen using Magnetic Resonance Imaging protocol. Ten patients scheduled for a bimaxillary osteotomy involving a combination of maxillary Le Fort I impaction procedure coupled with a sagittal split advancement of the mandible were select to form the study group. An Experimental design used to provide information in relation to masticatory muscle adaptation following orthognathic surgery. The study involved the contribution of two independent examiners that measured the changes in fibre orientation at the different jaw positions using AnatomicsTM software, at three different time moments. A combination of different parametric tests has been used to compare the different experimental variables. Results: Statistical differences have been identified between examiners measurements and between operations. There were no significant differences testing different times. Conclusions: The discrepancies between examiners probably arise from small variations in the experimental methodology used by them. The differences between operations reveal the masseter muscle adaptation following orthognathic surgery. The measurement of “P1 masseter muscle/ Zygomatic bone / process mastoid anterior angle” and “P2 masseter muscle / mandibular angle” can therefore be a valuable tool for controlling the reworking of masseter muscle upon orthognathic surgery.

Assessment of quality of life in a retrospective study of total oral rehabilitation of the upper jaw with transzygomatic fixation - Case series

Purpose: Zygomatic implants are becoming more common in oral rehabilitation of atrophic maxilla. Successful surgery and rehabilitation are mandatory for the achievement of a well-defined criteria of Quality of Life. However, there is a paucity of studies reporting on the Health-Related Quality of Life in patients undergoing oral rehabilitation. This article aims to developing a specific questionnaire for this particular surgical and rehabilitation procedure that could be an objective quality outcome measure of Quality of Life. This should improve our understanding of the impact of zygomatic implant placement on Quality of Life. Materials and Methods: The study was performed involving the Eastman Dental Institute - University College of London, the Faculty of Sciences - University of Lisbon, and two private practices in Portugal, C.E.R.O-Lisboa and Clitrofa. This was a retrospective study, evolving 30 patients undergoing TransZygomatic Surgery. A modification of the University of Washington – Quality of Life Questionnaire was designed for this work. The evaluation was made in three-time points: TP1 – Before surgery, TP2 - After surgery and TP3 - After final rehabilitation. Results: The means of the increased Quality of Life between the different time-points were found to be statistically significance at the level of 0.05, with a confidence interval of 95%. Conclusion: With this Questionnaire, important data was collected which should allow treatment developments to optimise patients Quality of Life.

Vertical Ridge augmentation in posterior mandible - Case report

Purpose: This clinical case describes a successful use of a non-resorbable membrane and mixture of autogenous particulated bone with anorganic bovine bone-derived mineral (ABBM) in a severe posterior mandible alveolar defect. Case report: A combined vertical and horizontal alveolar ridge augmentation was successfully achieved. Detailed clinical steps were described and demonstrated. The patient was rehabilitated with implant supported fixed partial denture with no pink ceramic. This two-staged procedure provides the amount of horizontal ridge width and vertical height to successfully place in the correct position the implants and achieve long term results. Conclusions: Multicenter, randomised clinical trials are necessary to compare this procedure with other potential clinical solutions.

​The importance of occlusal force measurement in orthognathic surgery - A pilot study

Purpose: This pilot investigation was designed to apply several, newly developed and more sophisticated methods of measuring muscle structure and function in a situation where adaptation of muscle is pivotal to the success of a therapeutic approach. Materials and Methods: Patients attending the combined orthodontic/orthognathic surgery clinic at the Clitrofa – Centro Médico, Dentário e Cirúrgico, in Trofa - Portugal were tested according to the protocol of Bite force and occlusal contact area were simultaneously measured with Bite Training Machine and Occlusal Force Diagnostic System. An Experimental design used for the measurement of occlusal force. The study involved the contribution of two independent examiners that measured the bite pressure (psi) in five different FSS sensors at three different time moments. A combination of different parametric tests has been used to compare the different experimental variables. Results: Neither the variation of examiner, nor the variations of time have shown to influence the bite pressure (psi). In contrast, the occlusal force measurement system developed has shown a high level of sensitivity due to the distribution of the five FSS sensors in the horseshoe-shaped form. A three-pressure region model fits the experimental data shown in this study, comprising a low-pressure region located in the anterior part of the dental arch, a medium-pressure region in the medial part of the dental arch and an high-pressure region located in the posterior part of the dental arch. Conclusions: The piezoelectric sensors used in the present study have shown high reproducibility of measurement. Due to the recent miniaturization of FSS sensors, the authors are developing new occlusal force measurement systems comprising a higher number of piezoelectric sensors, with the objective of attaining even higher sensitivity of measurement throughout the different region of the dental arches.

Mandibular dentigerous cyst: Enucleation and bone reconstruction – Case report

Purpose: The dentigerous cyst is the second most common odontogenic cyst in the jaws. These lesions are observed in routine examinations. The third molars and maxillary canines are the most affected teeth. Definition of marsupialization and enucleation techniques as well as consideration of important objective criteria for the treatment plan like cyst size, age, and proximity to anatomical structures, clinical importance of the tooth or teeth associated with the lesion and risk of bone fracture. This paper will present a case report treated by maneuver of decompression followed by enucleation and bone reconstruction. Case report: A 43-year-old female patient, Caucasian, attended the Oral-Maxillofacial Surgery consultation at Clitrofa - Centro Médico, Dentário e Cirúrgico, in Trofa - Portugal, to assess extraction of 3.8 and 4.8. On intraoral physical examination, a slight bulging of the cortical bone was noted in the region of the left external oblique line. Aspiration puncture was performed and a small amount of light-yellow liquid confirmed the cystic nature of the lesion. In a second stage, osteotomy through piezoelectric surgery was performed. The cystic capsule was excised together with the extraction of tooth 3.8 included and tooth 3.7. Bone regeneration was performed. The material obtained from the cystic cavity was sent for pathological examination, confirming the diagnosis of dentigerous cyst. During observation of the patient for twelve months, no hypoesthesia or any sign of recurrence of the lesion was observed. Conclusion: The technique preserved the neurosensory function and was effective for the enucleation and reconstruction of the lesion. Despite the clinical peculiarities of each case and the chosen treatment method, the prognosis of these lesions is favourable when appropriate therapy is used.

Induced pluripotent stem cells in periodontal regeneration - Narrative review

ABSTRACT Purpose: Periodontal disease is a severe infection caused by inadequate oral hygiene, resulting in tooth loss due to the bone destruction that supports the teeth. “Induced pluripotent stem cells” (iPSCs or iPS cells) is a sort of pluripotent stem cell that can be acquired out of adult somatic cells like peripheral blood mononuclear cells (PBMCs) or skin fibroblasts through inducing genetic reprogramming genes (Klf4, Oct4, c-Myc, and Sox2). Materials and Methods: This narrative review shows periodontal regeneration and bone regeneration using iPSCs and also highlights the drawbacks and challenges towards the future using iPSCs. Results and Discussion: Recent studies have shown greater regeneration when combination of iPSCs and enamel matrix derivates (EMD™) inserted into treatment of periodontal and bone defects. Conclusions: IPSC is a good alternative cell source in periodontal regeneration.

Modified shell technique for vertical ridge augmentation - Case report

Purpose: The placement of an implant is hindered by the absence of an adequate volume of bone. Vertical ridge augmentation is one of the most difficult and unpredictable procedures. The purpose of this report is to present a clinical case of vertical ridge reconstruction around a single tooth with a slight variation in the described ‘modified shell technique’. Case report: the patient had presented with 8.5mm vertical ridge deficiency in the region of central incisor #21. An autogenous graft was harvested from the symphysis. The cortical plate was thinned into the shell and divided into two parts to be placed on both buccal and lingual aspects. They were secured at the desired location using titanium screw as the traction screw since there was a lack of availability of the native bone. Remarkable vertical augmentation of the alveolar bone with minimal bone resorption was noticed on re-entry at 6months. Conclusions: This technique shows an alternate method of vertical augmentation over a small edentulous span presenting minimal amount of bone remaining to secure the grafting material.

Resorbable membrane of polyethylene glycol in Wistar rats for guided bone regeneration - Experimental study

Purpose: The aim of the present study was (1) to test whether or not the application of an in situ formed synthetic hydrogel, made of polyethylene glycol (PEG) used as a resorbable membrane for guided bone regeneration, will result in more amount of bone regeneration compared with an uncovered defect and (2) to evaluate if it can prevent the soft-tissue ingrowth into alveolar defects. Materials and Methods: Two critical size defects were created in seven Wistar rats. In the right side, an in situ formed hydrogel PEG membrane (Straumann MembraGel) was applied into the defect and the left one was kept empty as a control. After 60 days, animals were sacrificed and the calvarial bone was removed. The area of newly formed bone was determined by histomorphometrical analysis. For statistical analysis, the Mann-Whitney-U test was applied to model the amount of new bone formation. Results: The quantitative histomorphometric analysis obtained a percentage of newly formed bone for the test defects of 61,8% +/-22,2% and 53,8% +/-22,9% in the control group. The observed differences were not statistically significant. Conclusions The experimental PEG membrane was biocompatible and prevented soft-tissue ingrowth. There were no statistically significant differences between the groups.

Simplified protocol for horizontal and vertical post-extractive GBR with intentionally exposed PTFE membrane - Case series

Purpose: Post-extractive sites often need soft and hard tissue regeneration in order to place implants with optimal functional and aesthetic conditions. The author proposed several techniques for bone preservation and regeneration: most of them requires release incisions and coronally advanced flap to obtain primary closure, so regain a correct alignment of keratinized gingiva makes mandatory a further surgery with a connective tissue graft from secondary surgical site. Case report: Since May 2018 we applied with some adjustments Open Barrier Technique (proposed by E. Funakoshi, 2005) in 152 post-extractive alveolar preservation and GBR; after 3-6 months we placed 194 implants, with 100% success and survival rate. Conclusions: Our simplified protocol allows performing vertical and horizontal GBR in post-extractive sites without release incisions: non resorbable PTFE membrane protects wound and bone graft for 6-8 week; secondary healing ensures thick keratinized tissue and bone maturation, suitable to place implants after 3-6 months.

Interdisciplinary management of a severely compromised periodontal patient - Case report

Purposes: The aim of this case report is to suggest and discuss an up-to-date interdisciplinary approach to a complex periodontal case, adjusting different treatment strategies intra-individually based on the biological, functional and aesthetic dimensions of each patient. Case report: The case refers to a 42-year-old healthy male patient with IIIB generalized periodontitis. After cause-related therapy, the patient was submitted to periodontal resective surgery with fibre retention technique in the maxilla and surgical regenerative procedures in the posterior regions of the mandible with enamel matrix derivative and bovine xenograft. After Supportive Periodontal Therapy (SPT) institution the patient went through an aesthetic rehabilitation phase to minimize the disease sequelae. Conclusion: Modern evidence-based periodontal treatment options must be site-specific oriented in order to achieve the best clinical outcomes. A contemporary vision of periodontal treatment must go beyond the moment of establishment of an individualized SPT programme and these restorative solutions are very powerful tools to give back confidence and increase the self-esteem of our patients.