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.

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)

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.

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.

Tração osteogênica experimental do processo alveolar em cães / An experimental study of distraction osteogenesis in the alveolar process in dog

O presente estudo teve como objetivo avaliar a eficiência da técnica de tração osteogênica alveolar em relação aos aspectos clínicos, radiográficos e histológicos de áreas do processo alveolar de seis cães, com uso de aparelho de tração osteogênica intrabucal. Realizou-se osteotomia na região posterior da mandíbula e aparelhos de tração foram instalados em cada animal. Após sete dias, iniciou-se a ativação do aparelho na razão de 0,66 mm diários, durante nove dias. Após um período de consolidação de 60 dias foi colhida amostras para análise histológica. As observações clínicas indicam ganho vertical na área submetida à tração; ao exame radiográfico observou-se área radiopaca na câmara de regeneração e histologicamente foi identificada neoformação óssea, constituída por trabéculas interconectadas de osso não lamelar ou imaturo. A técnica cirúrgica de tração osteogênica alveolar foi eficiente, pois permitiu, com sucesso, o crescimento vertical do processo alveolar mandibular em cães

Permeabilidade da dentina radicular e infiltraçäo marginal em obturaçöes retrógradas, após apicectomia, in " vitro " / The root dentinal permeability and marginal infiltration in the retrograde filling, after apicoectomy, in vitro

Os autores estudaram "in vitro" dois fatores que podem ser responsáveis pelo insucesso na modalidade cirúrgica apicectomia com obturaçäo retrógrada: a infiltraçäo marginal e a permeabilidade da dentina radicular. Foram utilizados 32 dentes humanos, recém-extraídos, divididos em dois grupos. No grupo I, os dentes foram obturados com amálgama de prata e, no grupo II, os dentes foram obturados com pasta de óxido de zinco-eugenol para moldagens e empregado como corante o azul de metileno a 2 por cento, com ph 7,2, por 7 dias, a temperatura de 37ºC. Os resultados obtidos, através das inspeçöes em lupa estereoscópica levaram a conclusäo de que somente no Grupo II näo ocorreu infiltraçäo marginal

Enxertos ósseos autógenos em cranioplastia / Autogenous bone grafts in cranioplasty

No presente trabalho os autores fazem uma revisäo do emprego de enxertos ósseos autógenos em cranioplastia, descrevendo as suas indicaçöes e vantagens. E fazem uma descriçäo da técnica na qual utiliza-se enxerto ósseo da tábua externa da calota craniana para reparar os defeitos do crânio

Avaliação do vedamento apical de quatro materiais odontológicos utilizados em obturações retrógradas: estudo realizado "in vitro" / Evaluation of the apical sealing ability of four dental materials used in retrofilling: an \"in vitro\" study

No presente trabalho avaliou-se "in vitro" a capacidade do vedamento apical de quatro materiais odontológicos empregados em obturações retrógradas. Foram utilizados 40 caninos superiores humanos, recém extraídos e divididos em 4 grupos com dez dentes cada. No Grupo I, os dentes foram retrobturados com amálgama de prata com zinco, no Grupo II, os dentes foram retrobturados com ionômero de vidro, no Grupo III, os dentes foram retrobturados com resina composta com adesivo dentinário e no Grupo IV, os dentes foram retrobturados com pasta zinco-enólica para moldagens. Foi empregado como solução corante o azul de metileno a 2 por cento, com pH 7,2, por 60 horas, à temperatura de 37ºC. Após esse período, todas as amostras foram seccionadas ao meio longitudinalmente e avaliadas sob microscópio óptico quanto à infiltração do corante nas retrobturações. Os dados foram submetidos à análise de variância para comparações dos índices das infiltrações marginais, considerando os diferentes materiais retrobturadores, indicando que o Grupo IV (pasta zinco-enólica para moldagens) é superior aos demais, sendo as diferenças estatisticamente significantes (p=0,01); o Grupo I (amálgama com zinco) e o Grupo III (resina composta com adesivo dentinário) se equivalem entre si e são melhores do que o Grupo II (ionômero de vidro), porém, as diferenças não foram estatisticamente significantes (p=0,01)

Fascite nodular na mandíbula / Nodular faciitis in the mandible

Este artigo descreve um caso de fascite nodular na mandíbula e a necessidade do seu diagnóstico precoce, como também o tratamento realizado

Avaliaçäo de alguns materiais impermeabilizantes utilizados na verificaçäo de infiltraçäo marginal / Valuation of some impermeable materials used in the verification of marginal leakage

A proposta do presente trabalho foi estudar a eficácia da impermeabilizaçäo de alguns materiais impermeabilizantes utilizados na avaliaçäo de infiltraçäo marginal. Foram utilizados 40 dentes pre-molares íntegros superiores e inferiores, recém-extraídos e submetidos a impermeabilizaçäo com esmalte para unhas e resina epóxi. As amostras foram imersas durante 7 dias em soluçäo de Azul de Metileno a 2 por cento, com pH7,2, em uma temperatura de 37ºC. Os resultados obtidos através da inspecçäo em lupa estereoscópica levaram a conclusäo de que somente a associaçäo de uma camada de resina epóxi, seguida de uma camada de esmalte para unhas näo permitiu a penetrabilidade da soluçäo corante indicadora