Comparison Between an Expert Operator an Inexperienced Operator, and Artificial Intelligence Software: A Brief Clinical Study of Cephalometric Diagnostic.

INTRODUCTION: Artificial intelligence (AI) is constantly developing in several medical areas and has become useful to assist with treatment planning. Orthodontics and maxillofacial surgery use AI-based technology to identify and select cephalometric points for diagnostics. Although some studies have shown promising results from the use of AI, the evidence is still limited. Hence, additional investigation is justified. MATERIALS AND METHODS: In this retrospective study, 2 human operators (1 expert and 1 inexperienced) and 1 software analyzed 30 lateral cephalograms of individuals with orthodontic treatment indications. They measured 10 cephalometric variables and then 2 weeks later, repeated measurements on 30% of the sample. We evaluated the reliability of the measurements between the 2-time points and the differences in the means between the expert operator and the AI software and between the expert and inexperienced operators. RESULTS: There was high reliability for the expert operator and AI measurements, and moderate reliability for the inexperienced operator measurements. There were some significant differences in the means produced by the AI software and the inexperienced operator compared with the expert operator. CONCLUSION: Although AI is useful for cephalometric analysis, it should be used with caution because there are differences compared with analysis by humans.

Speech and the swallowing threshold in single implant overdenture wearers: A paired control study.

BACKGROUND: Single implant mandibular overdentures (SIMOs) can improve mastication in edentulous elderly people. However, little attention has been paid to their effects on articulation disorders and the swallowing threshold relative to those of conventional complete dentures (CDs). OBJECTIVE: To compare the effects of new conventional CD set and SIMOs on articulation disorders, mandibular movements during speech and swallowing threshold using a paired study design. METHODS: Twenty-two edentulous Brazilian Portuguese-speaking elderly people (mean age 66.7 ± 4.6 years) were first evaluated whilst wearing their old conventional CDs. Articulation disorders were analysed by audio and video recordings, mandibular movements during speech were measured by kinesiography, and the swallowing threshold was assessed by masticatory cycle counting and medium particle size (X50 ) calculation. Participants then received new conventional CDs, and evaluations were repeated 2 months later. Subsequently, single implants were installed in the midlines of subjects' mandibles, and the conventional CDs were converted to SIMOs. After 2 months of SIMOs use, the evaluations were repeated. Data were submitted to the Cochran-Mantel-Haenszel and ANOVA. RESULTS: No difference in articulation disorders was found between new conventional CD and SIMO use. The frequency of anterior lisp during /s/ and /z/ phoneme pronunciation was reduced with new conventional CD use relative to old conventional CD use (p < .05). The X50 decreased progressively with new conventional CD and SIMO use (both p < .05). CONCLUSION: SIMOs do not alter speech relative to new well-fitted conventional CDs, but improved the swallowing threshold, in edentulous elderly people.

Is Surgical Treatment Based on a 1-Step or 2-Step Protocol Effective in Managing the Odontogenic Keratocyst?

PURPOSE: The literature does not present any consensus on a uniform treatment plan for odontogenic keratocysts (OKCs) and does not provide adequate evidence for determining which modality is most effective in lowering morbidity or preventing recurrence. The purpose of this study was to compare the effectiveness of surgical treatment based on a 1- versus 2-step protocol. MATERIALS AND METHODS: The authors designed and implemented a retrospective cohort study and enrolled a sample of patients diagnosed with OKC from 1991 through 2018. The medical records of all cases were retrieved from files of the Oral and Maxillofacial Surgery Division of the Piracicaba Dental School (Piracicaba, Brazil). The predictor variable was treatment group (1- vs 2-step protocol). Statistical analysis was performed using Kaplan-Meier analysis, Mantel-Cox log-rank test, and proportional hazard regression analysis. RESULTS: The sample was composed of 72 patients (38 male) with a mean age of 40.72 years. Thirteen patients received 1-step treatment and 59 received 2-step treatment. The complex composed of the body, angle, and mandibular ramus was the site most frequently affected. In the individual Kaplan-Meier analysis for each presented variable only involved tooth was significant (P = .0128 by log-rank test), with the risk of relapse 4.23 times higher for the involved tooth than for the non-involved tooth. CONCLUSION: The 1- and 2-step protocols for treatment of OKCs are safe and appropriate as the first treatment option, offering a conservative and effective option with low morbidity. Treatment protocols associated with systematic monitoring promote a better quality of life for patients with low potential for complications.

Analysis of the Survival of Dental Implants Installed in Reconstructed Maxilla With Autogenous Iliac Crest Graft: 7- to 9-Year Follow-Up.

The aim of this study was to analyze the survival of dental implants installed in maxillae reconstructed with autogenous iliac crest grafts and to assess patient satisfaction with the treatment by means of a questionnaire. The study conducted medical record reviews and clinical/radiographic assessments of 10 patients with severe maxillary atrophy who had undergone reconstruction with autogenous iliac crest grafts and rehabilitation with dental implants between 2008 and 2011. Patients were assessed for the survival of the implants, considering implant diameter and length, smoking status, diagnosis of diabetes, type of loss, and region of implant loss. In addition, a questionnaire with specific questions on the patients' satisfaction with the treatment was administered. Seventy-six implants were installed in the sampled patients, and only 1 loss was observed (late loss in the anterior maxilla region) after an average follow-up of 7.9 years, which corresponds to a 98.60% survival rate. The installed implants were of the most frequently used dimension (3.75 × 10 mm). One sampled patient was diabetic, and a second patient was both diabetic and a smoker. No loss of implants was observed in these 2 patients. All patients reported being completely satisfied with the treatment and would undergo the procedure again or refer it to a friend/relative. Six patients reported regular maintenance of the prosthesis, and only 3 had changed the prosthesis prior to the time of questionnaire administration. The results of this limited study with a restricted sample population suggest that the reconstruction of the maxilla with an autogenous iliac crest graft provides both adequate implant survival and patient satisfaction.

Complications in Orthognathic Surgery.

The aim of this study was to analyze the presence of complications related to orthognathic surgery performed by surgeons in train. A retrospective study was conducted between 2005 and 2014, analyzing the clinical records of patients treated in the authors' Department. Patients who underwent orthognathic surgery were included, under a bidimensional analysis and with the conventional orthosurgical sequence; intraoperative complications were identified, such as the occurrence of a bad split, bleeding, tissue injury, among others and postoperative variables such as impaired sensation, infection, and alterations in the osteosynthesis systems. A statistical analysis was done using χ and Student t tests, considering a statistical significance when P < 0.05. Two hundred fifty patients were included with an average follow-up of 13 months; 62.8% were women and 37.2% were men; 18.8% of the subjects presented some type of intraoperative or postoperative complication; excluding relapse and complications due to loss of bonding of the orthodontic device, a 12.4% complication rate was observed; intraoperative complications were 8% and postoperative complications 10.4%. Only the sensorineural alterations were associated with the mandibular surgery (P < 0.05). Finally, orthognathic surgery is relatively safe and produces a low number of complications when it is performed by surgeons in train.

Evaluation of Failed Implants by Metallographic and Energy Dispersive X-ray Analysis.

OBJECTIVE: To evaluate the microscopic structure and chemical composition of titanium dental implants removed from patients with implant failure. MATERIALS AND METHODS: Thirty-eight dental implants removed from 29 patients between January 2012 and September 2014 were studied by metallographic analysis, and 7 of these implants were also studied by energy-dispersive x-ray (EDX) analysis. Medical records of these patients were examined. RESULTS: Dental implants were removed in a median of 54.6 ± 88.1 weeks after insertion. The lack of osseointegration without symptomatology or signs of infection was the main reason for implant failure (55.17%). Seventeen patients presented implant failure in the maxilla and 12 patients in the mandible. Metallographic analysis revealed that all the dental implants were manufactured from commercially pure titanium, presenting microscopic uniform appearance, with no "alpha case". The implants studied by EDX analysis presented between 99.85% and 99.87% of titanium and 0.13% and 0.15% of iron by mass. All the implants evaluated were within the ASTM specifications in both analyses. CONCLUSION: There was no relationship between dental implant failure and the microscopic structure and chemical composition of these devices.

Comparative Evaluation of Condylar Volume Between Patients With Unilateral Condylar Hyperplasia and Class III Dentofacial Deformity.

PURPOSE: To compare the condylar volume of patients with unilateral condylar hyperplasia (UCH) with that of patients with a Class III skeletal relation. MATERIALS AND METHODS: Twenty cone-beam computed tomograms of patients were analyzed. Images were divided into 2 groups: 10 from patients with transverse asymmetry of the face and 10 from patients with a Class III facial deformity. Patients' ages ranged from 15 to 30 years. Volumetric data were reconstructed using Dolphin 3D software (Dolphin Imaging & Management Solutions, Chatsworth, CA). This software measured the condylar volume above the deepest point of the sigmoid notch, the lower arch midline deviation, and the overjet. RESULTS: The condyle with hyperplasia exhibited the largest volume (1.97 ± 0.52 cm3) and a statistically significant difference compared with the contralateral condyle (χ2 = 14.30; P < .01). The Class III condyle exhibited relative symmetry of volume between the left and right sides. These condyles exhibited a larger volume compared with the non-hyperplastic condyles in the UCH group, with a statistically significant difference (χ2 = 6.22; P = .013; χ2 = 5.50; P = .019). CONCLUSIONS: Hyperplastic condyles were similar in volume to the condyles of patients with mandibular prognathism, suggesting that patients with a Class III skeletal relation could exhibit bilateral condylar hyperplasia.

Implant-supported maxillary denture retained by a telescopic abutment system: A clinical report.

An implant-supported fixed dental prosthesis is one of the treatment options for an individual with a completely edentulous maxilla. However, a screw-retained or cemented prosthesis can make oral hygiene difficult, especially for patients with a history of periodontal disease or disabilities. Compared with maxillary fixed dental prostheses, implant-supported overdentures offer similar retention and function and facilitate esthetics, phonetics, and hygiene. This report describes the prosthetic rehabilitation of a patient with an edentulous maxilla and a severe maxillomandibular discrepancy that involved the use of a novel prefabricated telescopic system to retain an implant-supported removable dental prosthesis.

Characteristics of Maxillofacial Trauma Among Alcohol and Drug Users.

The aim of the current study was to identify and compare the characteristics of maxillofacial trauma in alcohol and drug users with those of nonusers. A retrospective study was conducted using the medical records of patients treated for facial trauma between April 1999 and March 2012 at the Maxillofacial Surgery Division of the Piracicaba Dental School. The data were analyzed by descriptive analysis, binary logistic regression, and correlational analysis using SPSS 18.0 software. The results were considered relevant at P < 0.05. Medical records of 3724 patients with facial trauma were analyzed, of which 173 were illicit drug users and 19.36% reported alcohol intake. The use of illicit drugs was reported by 4.64%. The prevalent etiological factor among drug and alcohol users was interpersonal violence. The mandible was the face part most affected by fractures. Male patients exhibited increased odds of experiencing fractures (OR = 1.43), as did users of illicit drugs (OR = 1.62), when compared with nonusers. When faced with maxillofacial trauma, male drug users exhibited an increased chance of experiencing fractures. This knowledge should be used as a baseline to implement more efficient prevention strategies for this population.

Use of resorbable screws for autogenous onlay block graft fixation: a histological analysis in rabbits.

The aim of the present in vivo study is to histologically evaluate and compare the use of resorbable screws based on poly(L-co-D,L lactide) 70:30 for fixation of autogenous bone grafts in rabbit tibiae. As control group, titanium (Ti-6Al-4V Grade V) screws were used. For this purpose, 15 white New Zealand male rabbits, aged 6 months and weighing between 3.8 and 4.5 kg, were used. From each animal, 2 total-thickness bone grafts were removed from the cranial vault: one was stabilized with a resorbable screw while the other was stabilized with a metallic one. Animals were divided into 3 groups, according to the sacrifice period: 3, 8, and 16 weeks postoperatively. After histological processing, cuts were stained with hematoxylin and eosin and submitted for descriptive histological analysis under light microscopy. It was found that the fixation system based on the polymer showed a histological behavior similar to metallic screws. For both groups, the bone graft was incorporated, with the presence of bone formation between the graft and receptor site. In none of the groups were undesirable inflammatory responses or foreign body reactions observed. Based on histological findings and on this experimental model, it is possible to conclude that the internal fixation system based on the poly(L-co-D,L lactide) 70:30 polymer is effective for fixation of autogenous bone grafts, with results that are comparable to the titanium fixation system.

Mandibular condylectomy revisited: technical notes concerning the use of an ultrasonic system.

Condylar hyperplasia is a well-known pathologic entity with an established treatment protocol. Traditionally, saws and drills have been used in the condylar osteotomy. The use of ultrasonic systems has optimized many procedures in the maxillofacial area; however, exploration of the use of this technique for condylectomy has been limited. Ultrasonic systems offer several advantages, such as a decrease in the risk of blood vessel damage and clarity of the osteotomy. The present report addressed the scope of condylar osteotomy using ultrasonic systems.

Anatomic study for the horizontal cut of the sagittal split ramus osteotomy.

PURPOSE: The purpose of this study was to determine the posterior extension of trabecular bone and the height at which both the lateral and medial cortical bone layers of the mandibular ramus merge, using a reference point on the anterior margin of the mandibular ramus. MATERIALS AND METHODS: A total of 80 adult human mandibles were studied. Starting at reference point X, we marked a line running from the anterior margin to the posterior margin of the mandibular ramus on the medial aspect of the study samples. On 2 vertical sections of the right ramus, the level at which both the medial and lateral cortical bone layers merged was determined-H1 and H2, respectively. On the horizontal cross section of the left mandible at point X, the posterior extension of trabecular bone was determined. RESULTS: The median values of H1 and H2 were 10.45 mm and 4.52 mm, respectively. The median value of H2 was inversely proportional to the width of the ramus. The mean extension of trabecular bone posterior to point Z (where the upper margin of the lingula merges into the continuous medial aspect of the ramus) was 17.17 mm, bearing no correlation with the ramus width. CONCLUSION: Point X is a safe and easy-to-find anatomic reference to establish the level of a sagittal split ramus osteotomy (SSRO) horizontal cut. The wider the mandibular ramus, the closer to the mandibular foramen the SSRO horizontal cut should be performed. An SSRO horizontal cut should not be performed farther than 4 mm above line X. A safe posterior limit for the SSRO horizontal cut could not be determined.

Maxillary sinus floor augmentation using blood without graft material. Preliminary results in 10 patients.

PURPOSE: The maxillary sinus lift is recognized and stable, and there have been different innovations to optimize the technique. The aim of this study was to investigate the maxillary sinus lift technique with the use of a blood clot and without the use of a bone graft. MATERIALS AND METHODS: Ten patients were recruited for a unilateral sinus lift; patients without sinus pathology or other contraindication were selected. The maxillary sinus was accessed conventionally under local anesthesia followed by an osteotomy and a 1-cm(2) bony window access. The sinus membrane was detached and the window was repositioned above and stabilized with a 12- or 14-mm osteosynthesis screw introduced through the alveolar ridge. Dental implants were installed in the second surgical stage. Standardized panoramic radiographic checks were performed at every stage. RESULTS: Seven completely edentulous patients and 3 partially dentate patients were treated surgically. From the first to the second surgery, a bone gain of 2.37 mm was obtained, although loss of bone height was observed in 1 completely edentulous patient. In 7 patients, it was not possible to install the implants owing to insufficient bone height or inadequate bone quality. CONCLUSION: The protocol used in this investigation failed in the bone increase required for implant installation.

Retrospective Analysis of the Airway Space Changes in Dentofacial Deformity after Two-Jaw Orthognathic Surgery Using Cone Beam Computed Tomography.

Orthognathic surgery is used to modify anomalies in maxillomandibular position; this process can significantly affect the anatomy of the airway and cause functional changes. This study aims to define the impact of mandibular maxillary movement on the airway of subjects with dentofacial deformity. A retrospective study was conducted on subjects with Angle class II (CII group) and Angle class III (CIII group) dentofacial deformities. The subjects were treated via bimaxillary surgery; for all of them, planning was performed with software and 3D printing. Cone beam computed tomography (CBCT) was obtained 21 days before surgery and 6 months after surgery and was used for planning and follow-up with the same conditions and equipment. Was used the superimposition technique to obtain the maximum and minimum airway areas and total airway volume. The data were analyzed with the Shapiro-Wilk test and Student's t-test, while Spearman's test was used to correlate the variables, considering a value of p < 0.05. Thus, 76 subjects aged 18 to 55 years (32.38 ± 10.91) were included: 46 subjects were in CII group, treated with a maxillo-mandibular advancement, and 30 subjects were in the CIII group, treated with a maxillary advancement and a mandibular setback. In the CII group, a maxillary advancement of +2.45 mm (±0.88) and a mandibular advancement of +4.25 mm (±1.25) were observed, with a significant increase in all the airway records. In the CIII group, a maxillary advancement of +3.42 mm (±1.25) and a mandibular setback of -3.62 mm (±1.18) were noted, with no significant changes in the variables measured for the airway (p > 0.05). It may be concluded that maxillo-mandibular advancement is an effective procedure to augment the airway area and volume in the CII group. On the other hand, in subjects with mandibular prognathism and Angle class III operated with the maxillary advancement and mandibular setback lower than 4 mm, it is possible to not reduce the areas and volume in the airway.

Condylar Positional Changes in Skeletal Class II and Class III Malocclusions after Bimaxillary Orthognathic Surgery.

Orthognathic surgery is indicated to modify the position of the maxillomandibular structure; changes in the mandibular position after osteotomy can be related to changes in the position of the mandibular condyle in the articular fossa. The aim of this study was to determine changes produced in the mandibular condyle 6 months after orthognathic surgery. A cross-sectional study was conducted that included subjects who had undergone bimaxillary orthognathic surgery to treat dentofacial deformity of Angle class II (group CII) or Angle class III (group CIII). Standardized images were taken using cone-beam computed tomography 21 days before surgery and 6 months after surgery; measurement scales were used to identify the condylar position and its relations with the anterior, superior, and posterior joint spaces. The results were analyzed using the Shapiro-Wilk and Student's t-tests, while considering a value of p < 0.05 as indicating a significant difference. Fifty-two joints from 26 patients, with an average age of 27.9 years (±10.81), were analyzed. All subjects in both group CII and group CIII showed a significant change in the anterior, superior, and posterior joint spaces. However, postoperative changes in the position of the condyle in the articular fossa were not significant in the anteroposterior analysis. We conclude that orthognathic surgery causes changes in the sagittal position of the mandibular condyle in subjects with mandibular retrognathism and prognathism.

Recurrent mandibular dislocation treated by eminectomy.

Mandibular dislocations present with frequency; when they are recurrent and sustained over time, surgical treatment is indicated. Although different therapeutic techniques exist, the eminectomy is one of the most often applied. In this investigation, 3 cases are described where the bilateral eminectomy was performed for recurrent mandibular dislocation with 5 years of duration. No dislocation recurrence, postoperative pain, or functional alterations were observed in any of the patients. The bilateral eminectomy is a well-known procedure described in the literature, with good scientific support and constant modifications to optimize its indications and results. Compared with the results from other investigations, it is concluded that treatment with a bilateral eminectomy can be applied safely in cases of recurrent mandibular dislocations.

Central Giant Cell Granuloma in the Mandibular Condyle in a Teenager. A Case Report with Literature Review.

Central giant cell granulomas (CGCG) are not common in the mandibular condyle. In teenagers, the problem is more complex because of difficulties in diagnosis and treatment involving the potential growth of the mandibular process and development of the face. In this short communication a case is presented of an eleven-year-old female under diagnosis of central giant cell granuloma affecting the mandibular condyle treated surgically in two steps using a condylectomy and vertical ramus osteotomy at the first time and later orthognathic surgery, showing the clinical evolution after 13 years of follow-up. In addition, we performed a review of the scientific reports related to CGCG in the mandibular condyle to compare this treatment with others, in terms of follow-up and results. We concluded that the CGCG affecting the mandibular head can be properly treated with low condilectomy, vertical mandibular ramus sliding osteotomy, and discopexy.

TMJ Position in Symmetric Dentofacial Deformity.

The aim of this research was to analyze the facial class, presence of malocclusion, and the mandibular plane and to relate this to the mandibular condyle position. A cross-sectional study in subjects under analysis for orthognathic surgery was done. The mandibular plane, the gonial angle, and the molar class were included to compare the coronal and sagittal position of the condyle and the joint space observed in the CBCT. The measurements were obtained by the same observer at an interval of two weeks. In addition, the Spearman test was performed to determine the correlation using a p value < 0.05 to observe any significant differences. Eighty-nine male and female subjects (18 to 58 years old, 24.6 ± 10.5) were included. In the coronal section, subjects with CIII had a greater mediolateral distance (MLD, p = 0.0001) and greater vertical distance (SID, p = 0.0001) than subjects with CII. In terms of the skeletal class and the mandibular plane, it was observed that subjects in the CII group had a greater mandibular angle (open angle) (p = 0.04) than the CII group and was related to the anterior position of the condyle. The most anterior condylar position was observed in the CII group (p = 0.03), whereas a posterior condylar position was significant in CIII subjects (p = 0.03). We can conclude that the sagittal position of the TMJ was related to the mandibular plane and the skeletal class showing a higher mandibular angle and most anterior position of the condyle in CII subjects and a lower mandibular angle and most posterior position of the condyle in CIII subjects. The implications for surgical treatment have to be considered.

Speaking Space, Chewing Rotational Denture Movement, OHRQoL, and Patient Expectations for Single-Implant Mandibular Overdentures.

PURPOSE: To compare the speaking space, perceived rotational movement during chewing, and oral health-related quality of life (OHRQoL) of elderly people rehabilitated with new conventional complete dentures (CDs) and single-implant mandibular overdentures (SIMOs) using a paired design. Patient expectations for SIMO use were also evaluated. MATERIALS AND METHODS: The participants were 22 elderly users of unsatisfactory CDs. They received new sets of conventional CDs, and assessment was performed after 2 months of use. Speaking space was recorded with a kinesiograph while participants read a list of words. Participants were asked two questions about perceived posterior rotational denture movement during chewing. The Dental Impact on Daily Living (DIDL) questionnaire was used to examine OHRQoL, and a visual analog scale was used to quantify participants' SIMO expectations. Subsequently, the mandibular CDs were converted to SIMOs, and the assessment was repeated after 2 months of use. Speaking space and OHRQoL data were submitted to ANOVA and Student t test, and perceived mandibular movement and expectation data were examined using likelihood-ratio chi-square test. RESULTS: The speaking space and perceived rotational movement did not differ between CD and SIMO use. General performance and eating restriction DIDL scores increased after SIMO insertion. Participants' SIMO expectations regarding speaking, cleaning, esthetics, and general aspects were met. CONCLUSION: Relative to CD use, SIMO use did not change the speaking space or perceived rotational movement when chewing among elderly patients. It improved OHRQoL via enhancement of two DIDL dimensions and met most elderly patients' expectations.

In vitro mechanical test of grid plates for mandibular angle fractures.

This study evaluated, by mechanical testing, the strength of four-hole grid plates used for mandibular angle fracture fixation. Much has been discussed about the treatment of mandibular fractures with straight or curved plates. However, there are few studies about the use of grid plates. The geometry of such plates provides three-dimensional stability, resistance against torque associated with a low profile. Ninety polyurethane hemimandibles were used as substratum. The hemimandibles were divided into nine groups and fixation of the fractures was performed varying the type and position of plate and type of screw. An intact hemimandible group was used as control. It was possible to observe that plates positioned at the tension zone present the highest load values, both for dislocations of 3 and 5 mm. There was no statistical difference when plates with or without an intermediate bar were tested. The locking screws were more efficient than the non-locking screws when the plates were positioned at the neutral zone. Results allowed us to conclude that grid plates installed at the tension zone presented greater mechanical efficiency. If grid plates are positioned at the neutral zone, they should have an intermediate bar and be fixed with locking screws.