Proposal and Validation of a New Index to Assess the Difficulty of Lower Third Molar Extraction.

There is no current consensus on the parameters that determine the difficulty of mandibular third molar extraction in terms of the time required, which is essential to prevent complications and optimize the time of the intervention. This study aims to obtain, using the mathematical method of multiple linear regression, an equation that allows estimating the extraction time of a lower third molar according to its complexity, as well as to validate this equation in a sample of external wisdom teeth. METHODS: A prospective cohort study on a sample of patients of the Master of Oral Surgery of the University of Seville in which multiple linear regression coefficients were calculated with a subsequent validation study of the results in the sample of patients operated in the Hospital Palmaplanas of Mallorca. RESULTS: The regression line obtained after applying the statistical methodology to the cohort of patients from the University of Seville obtained significant dependent variables such as depth, roots, and odontosection. Once applied to the cohort of patients from the Palmaplanas Hospital in Mallorca, a regression coefficient was obtained between the data received and the estimated 0.770. CONCLUSIONS: The formula proposed in this article presents significant validity in the prediction of the surgical time of extraction of the lower third molars included.

Internal oblique line implants in severe mandibular atrophies.

BACKGROUND: Maxillary atrophy may be related to mechanical, inflammatory or systemic factors, being a consequence of a reduction in the amount and quality of available bone. Several surgical techniques have been developed for the restoration of bone volume needed for placing dental implants; guided bone regeneration or three-dimensional reconstructions with autologous bone, inter alia, are techniques described in the literature which demonstrate this, all of which preceded by a proper prosthetic surgical assessment. Even when the majority of authors recommend the use of these techniques prior to placing implants, it has been shown that implants with a smaller diameter and length may be placed in severely atrophied jaws without the need for performing any surgery, offering excellent results. MATERIAL AND METHODS: Twenty-four (24) implants were placed in six patients with severe mandibular atrophy. The implants were placed in the anterior sector and on an internal oblique line. Patients were rehabilitated with a total implant-supported prosthesis, with monitoring over a 10-year period. RESULTS: After a 12-month monitoring period, all the patients presented successful rehabilitation. Marginal bone loss in general (n=24 implants) was +0.11 mm ± 0.53. In the implants in zones 1 and 4 (posterior) it was +0.06 mm ± 0.48 and in implants in zones 2 and 3 (anterior), +0.14 mm ± 0.57. CONCLUSIONS: Implants can be placed in the anterior zone and on an internal oblique line in patients with severe mandibular atrophy, using a diameter and length adapted to bone availability, for later prosthetic rehabilitation, offering satisfactory results since phonetic and masticatory function can be restored, as well as facial and buccal aesthetics, in a single surgical operation, with minimum morbidity. Key words:Severe atrophy, implants, bone grafts, ridge atrophy, internal oblique line.

Influence of bone quality on the mechanical interaction between implant and bone: A finite element analysis.

OBJECTIVES: To evaluate the influence of bone type in terms of bone density and cortical bone thickness, on the stresses induced by two implants under compressive and oblique loads. METHODS: A numerical simulation technique based on the finite element method was applied. Two implant types (M-12 and Astra Tech) were introduced in a model matrix whose geometry was extracted from a real CBCT radiograph of the posterior mandibular region. The Young's module and Poisson's coefficient of the bone qualities described by Misch were calculated. Loads with amplitude of 400 N were exerted in two directions: compressive and 15° oblique to 5 mm above the uppermost part of the implant. RESULTS: The von Misses variant was analysed. Both implant types presented greater tension in the ​​cortical bone area than in the ​​trabecular bone region under compressive loading. For the oblique load condition, the stresses obtained in the cortical zone were significantly higher than those registered as a consequence of compressive loads in both implant types. CONCLUSIONS: Regardless of bone type, the M-12 implants presented lower tensions in the cortical bone than did the Astra implants. The tensions recorded for D3 and D4 bone types in the trabecular zone surrounding the M-12 implants were greater than those recorded for the Astra implants. CLINICAL SIGNIFICANCE: For both compressive and oblique loads, good mechanical behaviour was observed. The decrease in bone quality determines a worse stress distribution, and the cortical bone is overloaded. An efficient distribution of the forces may increase the implants' longevity.

Advantages of surgical simulation in the surgical reconstruction of oncological patients

BACKGROUND: Stereolithography, which consists of computer-aided designed/computer-aided manufactured (CAD-CAM) and computer simulations, is a manufacturing technologies used for the production of definitive models and prototypes printed in three dimensions, and is widely used in Oral and Maxillofacial Surgery. Surgical procedures using models made by these technologies offer several advantages. MATERIALS AND METHODS: This article describes three clinical cases of our experiences with patients diagnosed with squamous cell carcinoma and mandibular osteosarcoma, who underwent surgical removal of the lesions and subsequent mandibular reconstruction with a free fibula graft using surgical guides. RESULTS: In all three clinical cases, surgical guides were used for the mandibular osteotomy, fibula osteotomy, and graft placement in the recipient area. DISCUSSION: Surgical guidelines are useful for improving the accuracy of surgical interventions and are appropriate for many types of resection and mandibular reconstruction

Influence of dental treatment in place on quality of life in oral cancer patients undergoing chemoradiotherapy

BACKGROUND: This study aims to assess, in the population of patients with oral cancer treatment, the influence on the quality of life of two protocols of dental treatment: not ruled hospital treatment versus ruled hospital treatment. Matrial and METHODS: A quasi-experimental approach justified on ethical grounds was used. A total of 41 patients were included in the control group (not ruled treatment outpatient health center) and 40 in the experimental group (ruled hospital treatment). A total of 14 questions to both groups were conducted in three stages: before starting cancer treatment, during treatment and after treatment. the proportions of positive responses in groups and different times were compared using the chi-square test. RESULTS: Based on similar situations during cancer treatment were identified as six issues favorable to the experimental group difference. This number rose to nine after finishing oncological treatment. CONCLUSIONS: From our data we can confirm that planned dental treatment performed during the oral cancer treatment produces an improvement in the quality of life in patients with oral cancer

Evolution of oral health in oral cancer patients with and without dental treatment in place: Before, during and after cancer treatment.

BACKGROUND: This study aims to evaluate the influence of two dental treatment protocols, outpatient non-regulated treatment versus supervised hospital treatment, on the oral health of patients undergoing oral cancer (only radiochemotherapy treatment, not surgical) treatment. MATERIAL AND METHODS: The study used a quasi-experimental approach justified on ethical grounds. A total of 41 patients were included in the control group (outpatient non-regulated treatment) and 40 patients in the experimental group (in-hospital supervised treatment). The patients were treated only with chemotherapy (not surgical treatment was made) for oral cancer. This decision was taken by the oncology committee of the hospital without being influenced by this study. Data regarding plaque index, daily brushing habits, appearance of new cavities, need for extractions, appearance of candidiasis and use of prosthetics in both groups were collected at three points throughout the study: before starting cancer treatment, during treatment and after treatment. The values obtained using the Student's t-test and chi-squared were compared. RESULTS: Based on similar patient backgrounds, throughout cancer treatment the intervention under study resulted in a decrease in plaque index, necessary extractions, and incidence of decay, as well as an increase in daily brushing among other improvements in oral health observed in the experimental group versus the control group. CONCLUSIONS: From our data, we can confirm that supervised dental treatment performed during oral cancer treatment produced an improvement in the oral health of patients with oral cancer. Key words:Oral cancer, dental treatment, quality of life, oncology, dentistry.