Viscosupplementation in the upper and lower compartments of the temporomandibular joint checked by ultrasonography in an ex vivo and in vivo study.

Viscosupplementation (VS) of the temporomandibular joint (TMJ) aims to treat temporomandibular dysfunction (TMD) by stimulating synovial cells to improve intracapsular lubrication. The purpose of the present study was to assess a VS protocol planned with the aid of cone-beam computed tomography (CBCT) and checked by ultrasonography (US). The study was carried out in 3 stages. The first was to check the correspondence between the proposed facial reference points and the osseous components of the joint by means of CBCT. In the second stage, the upper and lower compartments of 20 TMJs of fresh frozen cadavers were injected with coloured liquids, and the accuracy of the technique was confirmed by dissecting the anatomical specimens. The third stage consisted of VS in 10 patients (20 TMJs), with real-time verification of the location of the needle tip by means of ultrasonography. CBCT confirmed the correct locations of the marked points used in the proposed VS protocol. The dissections showed that 13 of the 14 injections effectively reached the upper and lower compartments. The location of the needle tip was effectively verified by ultrasonography, confirming the correct access to both compartments. The proposed protocol was effective for accessing the upper and lower compartments of the TMJ. The evaluated protocol proved to be accurate, safe and clinically reproducible means of VS in the upper and lower compartments of the TMJ.

Accuracy evaluation of 3D-printed guide-assisted flapless micro-osteoperforations in the anterior mandible.

AIM: To evaluate the accuracy of tridimensional (3D)-printed guide-assisted flapless cortical bone micro-osteoperforations (MOPs) in the anterior mandible on a cadaver model. MATERIALS AND METHODS: Five human cadaver heads with complete dentition in the anterior mandible were used in the present study. Preplanning CBCT and intraoral surface scans were obtained. After alignment, drilling sites in the interradicular areas were planned from canine to canine, and a surgical guide was printed. The drilling was performed and a postprocedure CBCT scan was obtained to assess the accuracy of the procedure in relation to the virtual planning. RESULTS: The mean ± standard deviation (SD) mesiodistal interradicular space was 2.67 ± 0.84 mm. The mean ± SD error of the actual drilled hole compared with the planned position of the mesial drill site was 0.66 ± 0.33 mm, and to the distal drill site it was 0.56 ± 0.33 mm. There was a statistically significant difference between the number of times the teeth were hit mesially (10 out of 64 holes) and distally (none). CONCLUSIONS: The proposed technique, limited to an ex vivo scenario, provides a valid and reliable method for mandibular MOPs using a 3D-generated surgical guide. However, the risk of damaging adjacent radicular surfaces, particularly in areas with limited mesiodistal interradicular bone, needs to be considered. Further studies should focus on using thinner drills and adding other methods to stabilize the guide. Additionally, by selecting individuals and perforation sites with more mesiodistal interradicular bone, less damage is likely. (Int J Comput Dent 2022;25(4):387-0; doi: 10.3290/j.ijcd.b2599841).

A simplified CAD/CAM extraoral surgical guide for therapeutic injections.

Therapeutic injections into the craniofacial region can be a complex procedure because of the nature of its anatomical structure. This technical note demonstrates a process for creating an extra-oral template to inject therapeutic substances into the temporomandibular joint and the lateral pterygoid muscle. The described process involves merging cone-beam computed tomography data and extra-oral facial scans obtained using a mobile device to establish a correlated data set for virtual planning. Virtual injection points were simulated using existing dental implant planning software to assist clinicians in precisely targeting specific anatomical structures. A template was designed and then 3D printed. The printed template showed adequate surface fit. This innovative process demonstrates a potential new clinical technique. However, further validation and in vivo trials are necessary to assess its full potential.

Positioning accuracy assessment of minimally invasive percutaneous injection techniques for the treatment of temporomandibular disorders.

OBJECTIVE: The aim of the present study was to evaluate the accuracy of an extraoral CBCT-planned 3D-printed surgical guide aimed to percutaneous injection of substances into the temporomandibular joint (TMJ) and the lateral pterygoid muscle (LPM). METHODS: Nine human cadaver heads were used. Pre-planning CBCT and facial scans were obtained and three percutaneous injection sites were planned: one for the lower compartment of the TMJ and two for the LPM. A digital surgical guide was then designed with small titanium sleeves and printed by a 3D printer. After the injections, new CBCT scans with the needles in place were obtained in order to assess the accuracy of the procedure in relation to the virtual planning. RESULTS: The mean values for angle deviation were very low (range 1.13o-4.08o), the same happening for the mean difference in the length reached (range 1.82-2.64 mm), as well as for the mean difference in the needle tip dislocation (range 0.94-2.03 mm). CONCLUSION: The guide seems to be a reliable tool for accurate percutaneous injection of drugs into the inferior compartment of the TMJ and the LPM. Further studies are necessary to test the efficacy and validate the method in an in vivo study.

Zygomaticofacial, Zygomaticoorbital, and Zygomaticotemporal Foramina.

This study aimed to assess the anatomical and morphometric characteristics of the main zygomaticofacial (ZFF), zygomaticoorbital (ZOF), and zygomaticotemporal (ZTF) foramina in Brazilian dry skulls. 61, 69, and 42 skulls for ZFF, ZOF, and ZTF were evaluated by a single calibrated examiner for format, transverse and vertical diameters, and distances from the foramina to anatomical landmarks. Paired t test, Wilcoxon test, Pearson and Spearman correlations were used. Circular outline was the predominant format for ZFF and ZTF, while oval format was the most frequent for ZOF. Median distances from ZFF to frontozygomatic and zygomaticomaxillary sutures were higher on right and left sides of the skulls, respectively (P < 0.005). Mean ZOF transverse diameter was significantly higher on the right sides of the skulls and presented positive correlation between sides (P < 0.05). No differences were observed for mean vertical diameter and distance from the ZOF to the inferolateral angle of the orbit (P > 0.05). No significant difference was found for distance from the ZTF to zygomatic arch between sides (P > 0.05), although there was a positive correlation (P < 0.05). Significant differences were found when analyzing the anatomical and morphometric aspects of ZFF, ZOF, and ZTF.

Photobiomodulation with LED and laser in repair of mandibular socket rabbit: clinical evaluation, histological, and histomorphometric.

PURPOSE: The aim of this study was to evaluate the effects of LED and low-intensity laser on the healing of rabbit dental alveoli. METHODS: A total of 18 rabbits were divided into three groups of six; all rabbits underwent surgical extraction of the first lower right premolar. Following surgery, group 1 received LED irradiation, group 2 received laser irradiation, and group 3 were untreated controls. The initial applications of LED and laser began 48 h after tooth extraction and were given perpendicularly to the dental alveoli. The three groups were clinically evaluated for 18 days in the postoperative period. At 90 days, the rabbits were euthanized and the mandibular fragments containing the healing alveoli were collected. These fragments initially underwent computed tomography scans and bone density was measured in Hounsfield units. Following this, the fragments were processed and stained with hematoxylin and eosin for histological and histomorphometric analysis. RESULTS: The results were compatible between the clinical, histological, and histomorphometric parameters evaluated. There were no statistical differences between the LED and laser groups. However, the difference of the average bone density between laser and control group was not statistically significant. CONCLUSIONS: It was found that photobiomodulation with LASER and LED presented effects. However, only the LED demonstrated a beneficial effect on the process of bone repair in the dental alveoli of rabbits.

Styloid Process of the Temporal Bone: Morphometric Analysis and Clinical Implications.

Objective. To evaluate measures of the styloid process (SP) in Brazilian dry skulls. Methods. This study involves measurements of two points (lateral end posterior views) of 15 dry skulls held by the Morphology Department, Institute of Biological Sciences of Federal University of Minas Gerais. Results. There was a large variability for the length of left and right sides (in lateral and posterior views) of the styloid process. From the lateral view of the left and right styloid, the length of the SP ranged, respectively, from 10.22 mm to 69.73 mm and from 8.30 mm to 63.77 mm. From a posterior view of the left and right sides of the skulls, the values range, respectively, from 15.57 mm to 69.51 mm and from 15.64 mm to 69.44 mm. Conclusion. We believe that this study provides additional information about the frequency of elongated SP among the Brazilian population.

The use of digital periapical radiographs to study the prevalence of alveolar domes.

PURPOSE: In the present study, we coined the term 'alveolar dome' and aimed to demonstrate the prevalence of alveolar domes through digital periapical radiographs. MATERIALS AND METHODS: This study examined 800 digital periapical radiographs in regard to the presence of alveolar domes. The periapical radiographs were acquired by a digital system using a photostimulable phosphor (PSP) plate. The χ(2) test, with a significance level of 5%, was used to compare the prevalence of alveolar domes in the maxillary posterior teeth and, considering the same teeth, to verify the difference in the prevalence of dome-shaped phenomena between the roots. RESULTS: The prevalence of alveolar domes present in the first pre-molars was statistically lower as compared to the other maxillary posterior teeth (p<0.05). No statistically significant difference was observed in the prevalence of alveolar domes between the maxillary first and second molars. Considering the maxillary first and second molars, it was observed that the palatal root presented a lower prevalence of alveolar domes when compared to the distobuccal and mesiobuccal roots (p<0.05). CONCLUSION: The present study coined the term 'alveolar dome', referring to the anatomical projection of the root into the floor of the maxillary sinus. The maxillary first and second molars presented a greater prevalence of alveolar domes, especially in the buccal roots, followed by the third molars and second pre-molars. Although the periapical radiograph is a two-dimensional method, it can provide dentists with the auxiliary information necessary to identify alveolar domes, thus improving diagnosis, planning, and treatment.

Odontogenic infections in a dental emergency care unit: Eleven-year epidemiological analysis

Aim: To evaluate medical records from patients who underwent abscess drainage due to odontogenic infections in a public hospital in the city of Belo Horizonte (Minas Gerais, Brazil) during the period of 2003 and 2013. Methods: A retrospective analysis of cases which required drainage of abscesses due to dental infections. The types of therapeutic procedures analyzed were endodontic drainage, intraoral mucosa drainage, periodontal drainage, and extraoral drainage. Results: 162,902 cases required dental assistance, and 32,352 cases required drainage of abscesses due to dental infections. The most frequent approach was endodontic drainage (21,313 procedures); the least frequent procedure was extraoral drainage (922 procedures). Conclusions: Odontogenic infection is a common clinical condition in dental clinics. It should be diagnosed and treated as quickly as possible to avoid or minimize progression to more severe cases. (AU)

Assessment of hematologic parameters before and after bimaxillary orthognathic surgery.

PURPOSE: The purpose of the study was to evaluate changes of hematologic parameters in bimaxillary surgery. METHODS: Fifty-three patients were prospectively evaluated and divided into groups based on the surgical procedure and sex (predictor variables). Hemoglobin, red blood cells, hematocrit, and platelet were the primary outcome variables, operation time the secondary outcome, and the patients' age and weight the other variables. TRIAL REGISTRATION: NCT02364765 (U.S. National Institutes of Health, clinicaltrials.gov). RESULTS: There was statistically significant difference between all hematologic parameters before and after surgery, for both men and women, and for all surgical groups. There was a positive correlation between operative time and the decrease (in %) of the hematologic parameters. Linear regression analysis suggested that the Hb values decrease 0.083 % for every minute increase in the operation time, and 0.066, 0.066, and 0.010 % for RBC, Hct, and platelet count, respectively. There was a negative correlation between weight and all hematologic parameters. Correlations between age and hematologic parameters were not statistically significant. Almost all correlations between age, weight, sex, and the surgery group and the hematologic parameters were considered as very weak. Only one patient was transfused. CONCLUSIONS: It is suggested that operation time and patient's weight play a bigger role than patient's age and sex in the decrease of hematologic parameters after bimaxillary surgery.

A morphometric analysis of supraorbital and infraorbital foramina relative to surgical landmarks.

PURPOSE: The aim of the study was to examine the different morphometric variations of the supraorbital and infraorbital foramina of the facial skeleton on human skulls. METHODS: Eighty adult human dry skulls were studied. Measurements were made to analyze the degree of variability in the location of the supraorbital and infraorbital foramina. All measurements were done bilaterally. Variations were evaluated according to gender and side. RESULTS: There were 54 female and 26 male crania. Almost all mean measurements were longer in males than in females. A statistically significant difference was observed between the left and the right sides in 4 of 10 measurements. When comparing the morphometric measurements between left and right sides of male and female crania, 6 of 22 measurements were statistically higher in men than in women. CONCLUSIONS: The findings suggest that gender should be taken into account when the foramina studied here are to be located. The mean location of the infraorbital nerve was about 6.5 mm inferior to the inferior orbital rim (at the point where one can palpate the zygomatico-maxillary suture), about 25 mm from the midline, and about 43 mm below the supraorbital foramen in the same vertical line. Extra care should be taken during surgical dissection in the superior orbital region especially in the middle aspect of the superior orbital rim. In general, there were changes in measurements between the genders, but the ratios of these measurements with the horizontal and vertical measurements chosen remained the same between the genders.

Morphological variation in dentate and edentulous human mandibles.

PURPOSE: The aim of the study was to examine the different morphometric variations of the human mandibles, comparing between males and females in dentate and edentulous mandibles. METHODS: Eighty adult human dry mandibles were studied. Thirty-two variations were evaluated according to the presence and absence of teeth. Kolmogorov-Smirnov test was performed to evaluate the normal distribution of the morphometric variables. Levene test evaluated homoscedasticity. Student t tests and Mann-Whitney U tests, when indicated, were performed to compare each of the morphometric variables between dentate and edentulous mandibles. Statistical differences were considered when the P value was less than 0.05. RESULTS: Considerable numbers of measurements were statistically significantly different when comparing the influence of dental status on the anatomical measurements; the position and anatomical relations of the mental foramen and overall dimensions of the mandible are especially influenced. Only a few measurements were statistically significantly different in the comparison between males and females. CONCLUSIONS: The results of this research showed that the presence or absence of the teeth can alter mandibular shape and that mandibular edentulism may be associated with specific shape changes in the mandible. The dental status has a higher influence on the mandibular anatomy than the difference in gender.

Considerations of mandibular angle fractures during and after surgery for removal of third molars: a review of the literature.

BACKGROUND: Angle fractures are quite common considering that the angle of the mandible forms an area of lower resistance which contains a thicker upper border, a thin basilar bone, and the presence of an impacted mandibular third molar. Common complications of mandibular third molar surgery include alveolar osteitis (dry socket), secondary infection, nerve dysfunction, and hemorrhage. Reports of mandibular fracture during and after third molar removal are uncommon. PURPOSE: The purpose of this paper is to discuss the risk and predisposing factors that should be analyzed regarding the possibility of immediate and late mandibular angle fractures and their need for surgical treatment as a means through which to remove impacted molars. This study is based on a thorough review of the literature as well as on one immediate and one late mandibular angle fracture as described by the authors' own personal experience. CONCLUSIONS: The danger of an immediate jaw fracture can be avoided by means of proper instrumentation and by refraining from excessive force on the bone. The tooth should be sectioned in such a way as to minimize the extent of bone removal and force caused by instrumentation. The danger of a late jaw fracture can be avoided by precise diagnosis in cases of patients over 25 years of age, particularly men, whose tooth roots are superimposed on or adjacent to the inferior alveolar canal on a panoramic image, any local pathology and systemic disease or medications which may impair bone strength, and patients who present bruxism and are active athletes.

Traumatic displacement of maxillary permanent incisor into the nasal cavity.

PURPOSE: The purpose of this paper was to describe a case of unviable alveolar repositioning of an intruded tooth into the nasal cavity and to bring the subject of intrusive tooth injury among patients with dentoalveolar fractures to the attention of trauma surgeons. PATIENT: A 26-year-old male was involved in a car accident and crashed his mouth against the dashboard due to sudden deceleration. Intraoral examination revealed an anterior maxillary dentoalveolar fracture and absence of the central maxillary incisors, right lateral maxillary incisor, and left maxillary canine. Computed tomography showed a dislocated tooth in the nasal cavity. The "missing" left maxillary canine was easily recovered from the floor of the left nostril. CONCLUSIONS: Because complete dislocation of a tooth can cause a frontal sinus abscess, an airway complication, a respiratory tract obstruction, and a complicated lung abscess or sinusitis, anytime a tooth is not accounted for after a dentoalveolar trauma, the possibility that it has been fully intruded should be considered. Computed tomographic scan should be a routine diagnostic study in all cases with associated missing anatomical structures in the oral and maxillofacial region. The need to involve the dental professional in the initial assessment of dental trauma in emergency rooms in hospitals is important in order to identify how many teeth might be missing after dental trauma and to correctly reposition the avulsed teeth when possible.

Mandibular fractures associated with endosteal implants.

PURPOSE: The purpose of this study is to report four cases of mandibular fractures associated with endosteal implants and to discuss prevention and treatment of these types of fractures. DISCUSSION: To evaluate whether the patient's anatomy allows insertion of implants, radiological exams that demonstrate the height and the labial-lingual width are needed. To reduce the potential fracture problem, the mandible can be restrengthened with bone grafting techniques. The treatment of a fracture in an atrophic mandible is always a challenge because of the diminished central blood supply, the depressed vitality of the bone, and the dependence on the periosteal blood supply. The basic principles in fracture treatment are reduction and immobilization of the fractured site for restoration of form and function. CONCLUSIONS: If implants are placed in severe atrophic mandible, iatrogenic fracture of the mandible may occur during or after implant surgery because implant placement weakens the already-compromised mandible. A few millimeters of cortical bone should remain on both the labial and the lingual sites after the hole for insertion of an implant has been drilled. A 3-D surgical planning should be recommended at least in severe atrophic mandibles in order to prevent a severe reduction of bone tissue.

Inferior alveolar nerve lateral transposition.

PURPOSE: We determined the outcomes of 18 inferior alveolar nerve lateral transposition procedures in 15 consecutive patients. The advantages and disadvantages of this technique are discussed. RESULTS: The surgical protocol for inferior alveolar nerve transposition, followed by implant placement, presented excellent results, with complete recovery of the sensitivity within 6 months after the surgical procedure. DISCUSSION: Inferior alveolar nerve transposition is an option for prosthetic rehabilitation in cases of moderate or even severe bone reabsorption for patients that do not tolerate removable dentures. CONCLUSIONS: It is concluded that inferior alveolar nerve transposition can be safely and predictably performed with low risk to the mental nerve sensibility. Each patient should be advised of the chance of permanent nerve deficit throughout the distribution of the mental nerve. Alternative restorative solutions should also be considered.

Complication of local dental anesthesia: a broken needle in the pterygomandibular space

Broken dental needles are a rare event. They are difficult to find and remove. This paper reports a case of broken needle in the pterygomandibular space. The needle was localized using plain radiograph and removed under local anesthesia and venous sedation. Preventing needle breakage is important, as it can be a traumatic experience for the patient. Practitioners should routinely inspect dental needles before administering injections and minimize the number of repeated injections using the same needle. A meticulous injection technique is imperative. If breakage occurs, immediate referral to an oral and maxillofacial surgeon is necessary. It is strongly recommended that only an oral and maxillofacial surgeon may indicate and/or perform surgery to remove the broken needle.

Orthodontic or surgically assisted rapid maxillary expansion.

PURPOSE: The purpose of this study was to present, compare, and discuss the techniques for rapid maxillary expansion. DISCUSSION: The isolated transverse maxillary deficiency can be treated either orthodontically or surgically with rapid palatal expansion. In children and adolescents, conventional orthodontic rapid maxillary expansion has been successful when used before sutural closure. On the other hand, in skeletally mature patients, the possibility of successful maxillary expansion decreases as sutures close and the resistance to mechanical forces increases. CONCLUSIONS: The selection of an expansion technique depends on a number of factors. It is more likely to advocate surgery as the patient's age, transverse needs, or acceptance of the idea of surgery increases.

An intraoral surgical approach to the styloid process in Eagle's syndrome.

PURPOSE: The purpose of this study is to present an alternative method to the extraoral surgical approach to remove the elongated styloid process, the intraoral surgical approach, and discuss their advantages and disadvantages. A literature review is also presented. PATIENTS AND METHODS: A casuistic of intraoral surgical approach to remove the elongated styloid process is presented in five patients. RESULTS: Four patients experienced postoperative moderate pain and trismus for 1 week. Bilateral surgery in one patient caused severe trismus, great discomfort, and moderate difficulty in breathing. All were followed up for 6 months and showed complete relief of the oral pharyngeal symptoms and complete improvement in functional ability. DISCUSSION: The advantages of the external approach are good visualization and reduced possibility of deep neck space infection. The disadvantages are an external scar, longer duration of surgery, and risk of injury to the facial nerve. The advantages of the intraoral approach are that the method is safe, simple, and less time consuming and an external scar is avoided. The disadvantages are possible infection of deep neck spaces, risk of injury to major vessels, and poor visualization. CONCLUSIONS: Intraoral resection of the styloid process is a safe treatment technique of Eagle's syndrome. It is not recommended the bilateral intervention at the same surgery, because of possible great discomfort at postoperative time.