A depth-resolved quantitative evaluation method for non-carious cervical lesions treatment with optical coherence tomography.

OBJECTIVES: The aim of this study is prognostic assessment of surface smoothness and the presence of internal bubbles after treatment of non-cancerous cervical lesions (NCCLs) using optical coherence tomography (OCT). METHODS: After treatment with NCCLs, cross-sectional images of the lesion parts of the sample were non-invasively acquired and analyzed. The surface smoothness between tooth and resin, resin and cemento-enamel junction, and the presence bubble inside resin was confirmed. In addition, using an algorithm that distinguishes between resin and dental structure based on OCT cross-sectional images, we quantitatively analyzed the amount of resin used in treating NCCLs and acquired 3D images. RESULTS: The inner structure of the resin in each sample was checked, and the presence of bubbles was confirmed. In addition, the resin sections were separated from the tomographic images acquired by OCT to visualize 3D images. The volume of resin used in the treatment part of each NCCLs samples was quantitatively analyzed as 3.7216 ∼ 14.889 mm3. CONCLUSIONS: OCT is able to measure not only the surface abrasion provided by existing intraoral scanner, but also the size and depth location of interal bubbles, which is distinctive advantage of our method. Based on our results, OCT is a significant tool for qualitative and quantitative analysis of dental NCCLs treatment before and after treatment. CLINICAL SIGNIFICANCE: The study used OCT, a non-destructive diagnostic, to reveal the structure of the resin and the location and size of bubbles after NCCLs treatment. These findings could be golden standard in determining the prognosis of NCCLs treatment.

Comparative Study of Two Ways to Measure Root Trunk Length to Assess the Possibility of Crown Lengthening in Molars: Measuring Parallel to the Root Surface vs Parallel to the Tooth Axis

The aim of this study was to compare root trunk measurements taken parallel to the tooth axis (TA) to those taken parallel to the root surface (RS) in order to assess the decision-making implications of each method on crown-lengthening surgery. A total of 672 root trunks were measured via CBCT in two planes: TA and RS. The possibility of performing crown lengthening in each clinical situation based on the distance from the cementoenamel junction (CEJ) to the crestal bone (CB) after ostectomy (CEJ-CB) was judged and compared between groups. When RS was used as a reference point, the proportions of cases that judged crown lengthening to be possible were 83.63%, 59.08%, and 39.18% for CEJ-CB values of 4, 5, and 6 mm, respectively. When TA was used instead, those proportions decreased by 3.87% to 7.29%. The lingual root trunk of the lower first molar (LFL) with a CEJ-CB of 4 to 5 mm emerged as the most problematic area; here, the difference between reference planes occurred with one out of every six teeth. Within the limits of this study, utilizing TA for surgical crown-lengthening treatment planning is not ideal because it may lead to extraction of many savable teeth.

The precision of gingival recession measurements is increased by an automated curvature analysis method.

BACKGROUND: The extent of gingival recession represents one of the most important measures determining outcome of periodontal plastic surgery. The accurate measurements are, thus, critical for optimal treatment planning and outcome evaluation. Present study aimed to introduce automated curvature-based digital gingival recession measurements, evaluate the agreement and reliability of manual measurements, and identify sources of manual variability. METHODS: Measurement of gingival recessions was performed manually by three examiners and automatically using curvature analysis on representative cross-sections (n = 60). Cemento-enamel junction (CEJ) and gingival margin (GM) measurement points selection was the only variable. Agreement and reliability of measurements were analysed using intra- and inter-examiner correlations and Bland-Altman plots. Measurement point selection variability was evaluated with manual point distance deviation from an automatic point. The effect of curvature on manual point selection was evaluated with scatter plots. RESULTS: Bland-Altman plots revealed a high variability of examiner's recession measurements indicated by high 95% limits of agreement range of approximately 1 mm and several outliers beyond the limits of agreement. CEJ point selection was the main source of examiner's variability due to smaller curvature values than GM, i.e., median values of - 0.98 mm- 1 and - 4.39 mm- 1, respectively, indicating straighter profile for CEJ point. Scatter plots revealed inverse relationship between curvature and examiner deviation for CEJ point, indicating a threshold curvature value around 1 mm- 1. CONCLUSIONS: Automated curvature-based approach increases the precision of recession measurements by reproducible measurement point selection. Proposed approach allows evaluation of teeth with indistinguishable CEJ that could be not be included in the previous studies.

Soft and Hard Tissue Remodeling after Endodontic Microsurgery: A Cohort Study.

INTRODUCTION: The aim of this study was to investigate the impact of the incision type, with or without a coronally repositioning flap (CRF), on soft tissue healing and crestal bone remodeling after endodontic microsurgery (EMS). METHODS: Clinical pictures and cone-beam computed tomography images from 47 patients (120 teeth) taken before surgery and at the follow-up appointment were included in this study. Clinical pictures were qualitatively evaluated by 2 endodontists for the gingival marginal level (GML) (recession, same position, or coronal root coverage), papillary height (same position/receded), and for presence/absence of scars for each tooth. Cone-beam computed tomography images were used to calculate the changes in the distance between the cementoenamel junction and the crestal bone level (CBL) between the preoperative and follow-up scans. Statistical analyses were performed to determine a correlation between patient-related factors (age, sex, tooth type, position, and presence/absence of a crown), incision techniques, and changes within the CBL. RESULTS: Gingival recession was more prevalent in mandibular teeth, molar teeth, and teeth that received intrasulcular or papilla-based incisions (P < .05). Scar formation was affected by the flap design (P < .05). CRF was the only technique resulting in coronal root coverage (P < .05). There were no changes observed in the papillary height between the various flap designs. There was also no statistically significant difference in the crestal bone height between the preoperative and follow-up scan measurements (P > .05). CONCLUSIONS: Soft tissue changes are evident after EMS and can be affected by the flap design selected, as well as the site being treated. Application of CRF can improve the position of GML after EMS. There are insignificant changes within the CBL at the facial aspect of the root after EMS.

Is Hypoxia Related to External Cervical Resorption? A Case Report.

Despite the fact that external cervical resorption (ECR) is a well-known and rather frequently met condition, the driving force of this phenomenon still remains unclear. Recently, hypoxia has been linked to ECR. Thus, the aim of this work was to investigate the existence of hypoxia in ECR and hypothesize on its role at the time of extraction. This work is a case study of a tooth with ECR. ECR diagnosis was based on clinical and radiographic examination with cone-beam computed tomographic imaging. The extracted tooth was further analyzed by using nanofocus computed tomographic imaging and immunohistology. To investigate the 3-dimensional extent and pattern of ECR, in vivo cone-beam computed tomographic imaging and ex vivo nanofocus computed tomographic imaging were used. Different histologic stains were used to investigate the presence of a hypoxic environment and to gain a better insight into the involved cells, neuronal structures, and remodeling process during ECR. A higher distribution of hypoxia-inducible factor 1a-positive cells was found in the apical part of the resorption area when compared with the coronal area of the resorption. In addition, a similar distribution of hypoxia-inducible factor 1a-positive odontoblasts was observed in the pulp. Three-dimensional analysis of the calcification of the pulp revealed the formation of pulp stones in areas with higher hypoxia. Histology showed that remodeling during ECR can occur according to a layered pattern. This investigation confirms the presence of hypoxia in ECR and shows that there is a gradient of hypoxia within the ECR lesion and surrounding tooth structure. The hypoxic environment within the pulp is also indicated by the formation of pulp stones.

Tomographic late evaluation of xenogeneic bone grafts in sockets of impacted third molars

Abstract It is necessary to preserve height and thickness of the alveolar bone to facilitate rehabilitation with osteointegratable implants or simply to maintain bone integrity after extraction. Biomaterials associated with resorbable or non-resorbable membranes, when placed in the region of the socket, may contribute to avoid this unwanted reabsorption. Objective The objective of this study was to evaluate the distance of the crest of alveolar ridge to the cementoenamel junction (CEJ) of the lower second molars and the bone density of the third molar socket filled with Gen-Tech®, 5 years after an exodontia using cone beam computed tomography (CBCT) to visualize the central region of the sockets, without overlapping of the buccal and lingual cortical bones. Material and Methods A total of 12 individuals from an initial group of 39 patients submitted to extraction of the unruptured lower third molars and grafting of an association of inorganic bovine bone matrix, organic bovine bone matrix, collagen and bone morphogenetic proteins (BMP) (Gen-Tech®) on one side and the contralateral sockets filled only by clot, returned to control after 5 years, and were submitted to CBCT. The distance from the crest of alveolar bone to the CEJ and the bone density (BD) were measured using the i-CAT Vision Software. Results The results showed that the distance from the crest of alveolar bone to the CEJ in the control group was similar to that observed before the exodontia; in the experimental group, this distance was smaller. Considering the BD measurement, a significantly higher density was observed in the experimental group (p<0.05). Conclusion Part of the biomaterial was not absorbed and allowed the stability of the evaluated parameters after 5 years, being able to be used as a bone substitute in the socket.

Minimally Invasive Treatment of Class 4 Invasive Cervical Resorption with Internal Approach: A Case Series.

Invasive cervical resorption (ICR) is a type of external resorption that can involve the coronal, middle, and apical parts of the root in its advanced stages. The diagnosis and treatment of ICR depend on the extent of the resorption into the dentin. The treatment of advanced ICR is challenging, and these teeth have poor prognoses. This article describes 4 cases of class 4 ICR diagnosed by using cone-beam computed tomography and treated with a minimally invasive internal approach with sodium hypochlorite irrigation and calcium hydroxide dressing. All cases were followed for at least 3 years.

Evaluation of Impacting Factors on Facial Bone Thickness in the Anterior Maxillary Region.

BACKGROUND: The goal of the current study was to measure the width of the labial alveolar bone of the overlying maxillary anterior teeth, based on cone-beam computed tomography (CBCT) images, and the distance between cementoenamel junction (CEJ) and bone crest in adult patients. METHODS: A cross-sectional study was performed using a sample of 132 tomographic scans. Intact maxillary anterior with healthy periodontium and teeth was randomly selected and afterwards assessed by 2 calibrated and independent reviewers. RESULT: The average bone thickness at 2 mm from the CEJ of the maxillary right central incisors was 0.63 ±â€Š0.69 mm and over the maxillary left central incisors was 0.59 ±â€Š0.71 mm. Moreover on the right and left lateral maxillary incisors, the crestal bone width averaged 0.64 ±â€Š0.81 and 0.61 ±â€Š0.7 mm, respectively. Concerning the maxillary canine region on both sides, the crestal bone thickness averaged 0.72 ±â€Š0.9 and 0.66 ±â€Š0.69 mm, in the maxillary right and left the canine regions, respectively. Furthermore, according to the gender and systemic disease, there were some recognizable differences in the facial bone thickness between the left and the right side. CONCLUSIONS: The current study has advocated the outcome of a mostly thin buccal bone overlying the maxillary anterior teeth; hence, clinicians should always consider the thickness of the facial cortical plate of the extraction site and the positioning of the implant placement in the socket.

External cervical resorption: diagnostic and treatment tips

ABSTRACT External cervical resorption is caused, almost exclusively, by dental trauma - especially those characterized by concussion - and is a dental disease to be diagnosed and treated accurately by endodontists. However, the vast majority of the cases is initially diagnosed by an orthodontist, due to the imaging possibilities in standardized documentations. Among the causes of external cervical resorption, it is common to mistakenly attribute it to orthodontic treatment, traumatic occlusion or even to chronic inflammatory periodontal disease. External cervical resorption is associated to dental trauma in several situations mentioned in this paper. In old cases, and eventually still nowadays, it may have been induced by internal tooth bleaching, which is increasingly less frequent in endodontically treated teeth. There are some tips to be followed and some care that must be taken during the diagnosis and treatment of external cervical resorption clinical cases. The present study lists foundations that will allow the professional to perform safely and accurately in each specific case. Some of these tips and care measures are of orthodontic nature.

RESUMO A reabsorção cervical externa é provocada, quase exclusivamente, pelo traumatismo dentário, especialmente os do tipo concussão. Ela constitui uma doença dentária a ser diagnosticada e tratada com precisão pelo endodontista, mas a grande maioria dos casos é inicialmente diagnosticada pelo ortodontista, em função das oportunidades imagiológicas nas documentações padronizadas. Entre as causas da reabsorção cervical externa, é comum atribuí-la equivocamente ao tratamento ortodôntico, à oclusão traumática ou, ainda, à doença periodontal inflamatória crônica. A reabsorção cervical externa está associada ao traumatismo dentário em várias situações mencionadas neste trabalho. Em casos mais antigos - e ainda hoje, eventualmente -, pode ter sido induzida pelo clareamento dentário interno, cada vez menos realizado em dentes endodonticamente tratados. Algumas dicas e cuidados devem ser tomados no diagnóstico e no tratamento dos casos clínicos de reabsorção cervical externa. No presente trabalho, são listados fundamentos para que o clínico possa atuar com segurança e precisão em cada caso, especificamente. Nessas dicas e cuidados, encontram-se alguns de natureza ortodôntica.

CBCT Use in Endodontic Diagnosis.

Endodontic diagnosis and treatment planning has taken a giant leap forward due to introduction of CBCT in dentistry. While conventional 2-D radiographs remain the most cost-effective and routine method to evaluate a patient's dentition, their diagnostic potential is limited. The 3-D manipulation of images that CBCT offers provides better insight into diagnostic dilemmas and complicate treatment decisions. Despite the advantages of CBCT imaging, it should be used complimentary to 2-D radiography, not as a replacement. The principle of ALARA (in which patients should be exposed to radiation "as low as reasonably achievable"), still applies to this technology. CBCT should not be used routinely in the absence of clinical signs or symptoms that necessitate a more in-depth view of a tooth and surrounding structures. In other words, if a conventional 2-D radiograph will suffice, then a CBCT pretreatment scan is not necessary. However, if more information is needed to make an accurate diagnosis, a 3-D CBCT image is justified and highly beneficial as shown through several case examples share in this article.

A six-site method for the evaluation of periodontal bone loss in cone-beam CT images.

OBJECTIVES: In contrast to two-dimensional planar images, a measuring point is hardly repeatedly determined in a CBCT image when alveolar bone loss is assessed. Thus, the aim of the present study was to propose a six-site measuring method, which is closely related to anatomical structure, for the evaluation of alveolar bone loss in CBCT images. METHODS: 150 measuring points in 11 molars and 14 premolars from 6 patients (2 males and 4 females) were included. CBCT images of the teeth were acquired prior to periodontal surgery. Four observers measured the distances between cemento-enamel junctions and the apical bases of the periodontal bone defect at the mesio-buccal, mid-buccal, disto-buccal, mesio-lingual/palatal, mid-lingual/palatal and disto-lingual/palatal sites in CBCT images. Direct measurements of the six sites were correspondingly obtained in the subsequent periodontal surgeries. Differences between the distances measured in the CBCT images and during the surgery were analysed. Interobserver and intraobserver variances were tested. RESULTS: No statistically significant difference was found between the surgical and CBCT measurements (p = 0.84). Diagnostic coincidence rates of four observers were 86.7%, 87.3%, 88.7% and 88.0%, respectively. The interobserver (p = 0.95) and intraobserver (p = 0.30) variances were not significant. CONCLUSIONS: The six-site measuring method validated in the present study may be a useful three-dimensional measuring method for the evaluation of periodontal disease.

Effect of Eruption Status of the Mandibular Third Molar on Distal Caries in the Adjacent Second Molar.

PURPOSE: To analyze the effect of the eruption status of the mandibular third molar (MTM) on distal caries in the mandibular second molar (MSM) by cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Five hundred CBCT images of MTMs from 469 patients were evaluated. Presence of distal caries in MSMs, impaction depths and angulations of MTMs, cementoenamel junction (CEJ) distances between distal MSMs and mesial MTMs, presence of pericoronitis in MTMs, and patient characteristics (age and gender) were assessed. Data were analyzed by χ(2) test, univariate and multivariate logistic regression analyses, and Spearman correlation analysis. Descriptive and bivariate statistics were computed and the P value was set at .05. RESULTS: The overall prevalence of distal caries in the MSM was 52.0%. According to the classification of Pell and Gregory, position A was the impaction depth at which most distal caries in MSMs were present (P = .036). For angulation of the MTM, when mesial angulations were 43° to 73°, MSMs developed more distal caries (P < .0001). For the CEJ distance between the distal MSM and the mesial MTM, when distances ranged from 6 to 15 mm, distal caries in MSMs occurred more frequently (6 to 8 mm, P < .0001; 8 to 15 mm, P = .037). Furthermore, there was a linear correlation between angulation of the MTM and the CEJ distance between the distal MSM and the mesial MTM (P < .0001). CONCLUSIONS: Impaction depth and angulation of the MTM are associated with distal caries in the MSM. Angulation of the MTM is more stable and reliable than the CEJ distance between the distal MSM and the mesial MTM for the estimation of risk factors related to the MTM.

A cross-sectional study of the associations between periodontitis and carotid arterial calcifications in an elderly population.

OBJECTIVE: To evaluate if the presence of periodontitis is associated with carotid arterial calcifications diagnosed on panoramic radiographs in an elderly population. MATERIALS AND METHODS: Study individuals were randomly selected from the Swedish civil registration database representing the aging population (60-96 years) in Karlskrona, Sweden. Bleeding on probing (BOP) and the deepest probing measurement at each tooth were registered. The proportions of teeth with a probing depth ≥ 5 mm and the proportion of teeth with bleeding on probing were calculated. Analog panoramic radiographs were taken and the proportion of sites with a distance ≥ 5 mm between the alveolar bone level and the cement-enamel junction (CEJ) were assessed. A diagnosis of periodontitis was declared if a distance between the alveolar bone level and the CEJ ≥ 5 mm could be identified from the panoramic radiographs at > 10% of sites, probing depth of ≥ 5 mm at one tooth or more and with BOP at > 20% of teeth. RESULTS: Readable radiographs were obtained from 499 individuals. Carotid calcification was identified in 39.1%. Individuals were diagnosed with periodontitis in 18.4%. Data analysis demonstrated that individuals with periodontitis had a higher prevalence of carotid calcifications (Pearson χ(2) = 4.05 p < 0.05) and with a likelihood of 1.5 (95% CI = 1.0, 2.3, p < 0.05). CONCLUSIONS: Data analysis demonstrated a significant association between periodontitis and carotid calcification.

Changes of Root Length and Root-to-Crown Ratio after Apical Surgery: An Analysis by Using Cone-beam Computed Tomography.

INTRODUCTION: Apical surgery is an important treatment option for teeth with post-treatment periodontitis. Although apical surgery involves root-end resection, no morphometric data are yet available about root-end resection and its impact on the root-to-crown ratio (RCR). The present study assessed the length of apicectomy and calculated the loss of root length and changes of RCR after apical surgery. METHODS: In a prospective clinical study, cone-beam computed tomography scans were taken preoperatively and postoperatively. From these images, the crown and root lengths of 61 roots (54 teeth in 47 patients) were measured before and after apical surgery. Data were collected relative to the cementoenamel junction (CEJ) as well as to the crestal bone level (CBL). One observer took all measurements twice (to calculate the intraobserver variability), and the means were used for further analysis. The following parameters were assessed for all treated teeth as well as for specific tooth groups: length of root-end resection and percentage change of root length, preoperative and postoperative RCRs, and percentage change of RCR after apical surgery. RESULTS: The mean length of root-end resection was 3.58 ± 1.43 mm (relative to the CBL). This amounted to a loss of 33.2% of clinical and 26% of anatomic root length. There was an overall significant difference between the tooth groups (P < .05). There was also a statistically significant difference comparing mandibular and maxillary teeth (P < .05), but not for incisors/canines versus premolars/molars (P = .125). The mean preoperative and postoperative RCRs (relative to CEJ) were 1.83 and 1.35, respectively (P < .001). With regard to the CBL reference, the mean preoperative and postoperative RCRs were 1.08 and 0.71 (CBL), respectively (P < .001). The calculated changes of RCR after apical surgery were 24.8% relative to CEJ and 33.3% relative to CBL (P < .001). Across the different tooth groups, the mean RCR was not significantly different (P = .244 for CEJ and 0.114 for CBL). CONCLUSIONS: This CBCT-based study demonstrated that the RCR is significantly changed after root-end resection in apical surgery irrespective of the clinical (CBL) or anatomic (CEJ) reference levels. The lowest, and thus clinically most critical, postoperative RCR was observed in maxillary incisors. Future clinical studies need to show the impact of resection length and RCR changes on the outcome of apical surgery.

Root resorption after leveling with super-elastic and conventional steel arch wires: a prospective study.

BACKGROUND: The aim of this prospective study was to compare root resorption after the leveling phase of treatment, performed by either super-elastic or conventional multi-stranded stainless steel arch wires. METHODS: From a total of 156 future orthodontic patients in a private clinic, 82 were included in the study after excluding those who earlier had orthodontic or endodontic treatment or signs of resorption. Patients were equally arbitrary allocated into two groups, where leveling was performed either with super-elastic heat-activated or conventional multi-stranded stainless steel arch wires. Root length loss was calculated using pre-treatment and post-leveling periapical radiographs. RESULTS: The use of super-elastic arch wires did not significantly increase the severity of root resorption, except for tooth 31, while it reduced leveling time compared to conventional stainless steel wires. Crossbite of maxillary lateral incisors seemed to be a risk factor for resorption. CONCLUSION: Incisor root resorption after leveling did not differ significantly between patients treated with super-elastic and conventional stainless steel arch wires, except for a mandibular incisor.

Periodontal disease decreases insulin sensitivity and insulin signaling.

BACKGROUND: The purpose of this study is to investigate whether local inflammatory events, such as periodontal disease, are able to increase tumor necrosis factor-alpha (TNF-α) plasmatic concentration and decrease insulin sensitivity and insulin signaling in non-diabetic rats. METHODS: Forty-eight male Wistar rats (2 months old) were divided into two groups, with either ligature-induced periodontal disease (LPD) or control conditions (CN). Experiments were performed in both groups 28 days after ligature placement. Plasmatic concentration of glycemia and TNF-α (n = 10) were analyzed by the glucose oxidase and enzyme-linked immunosorbent assay method, respectively. Insulin sensitivity (n = 7) was measured using the insulin tolerance test. Insulin signal transduction (n = 7) was measured by pp185 tyrosine phosphorylation status in insulin-sensitive tissues using the Western blotting method. RESULTS: The LPD group showed decreased insulin sensitivity (P <0.05), although no glycemic alterations were noted (P >0.05). TNF-α plasmatic concentration was higher in LPD rats compared to CN rats. In addition, a decrease in the pp185 tyrosine phosphorylation status was observed after insulin stimulus in both white adipose and skeletal muscle tissues of the LPD group compared with the CN group. CONCLUSIONS: LPD is able to cause alterations to both insulin signaling and insulin sensitivity, probably because of the elevation of TNF-α plasmatic concentration. Thus, the present results emphasize the importance of the prevention of local inflammatory diseases, such as periodontitis, to prevent diabetes mellitus.

Mini-implant insertion based on tooth crown references: a guide-free technique.

Mini-implant insertion requires accurate surgical technique. This study shows an insertion technique using only tooth crown references; its scientific basis is evaluated radiographically. The sample consisted of 213 inter-radicular septa, evaluated in 53 bitewing radiographs. The proximal contour of adjacent tooth crowns was used to define septum width. The midpoint of the septum width was linked to the interdental contact point to determine septum midline. The distances from septum midline to mesial and distal teeth were measured to evaluate the septum midline centralization degree in two different septum heights. The difference between mesial and distal distances represented the septum midline deviation degree. The mesial and distal distances were compared by t-tests, and the septum midline deviation was correlated with septum height using Pearson's correlation test. The mesial and distal distances were not statistically different in the midpoint of the septum height, but they were different at the apical septum height. There was a moderate correlation (r=0.45) between septum midline deviation and septum height. The tooth crown references evaluated on interproximal radiographs determine a high centralization degree of the septum midline on which the insertion site could be defined. The greater centralization degree was observed at the coronal septum area.

Alveolar bone level is not associated with vitamin D receptor gene polymorphism and bone density in mandible.

The objective of this study was to determine, using digital panoramic radiographs, whether the bone level at the alveolar crest is related to the mandibular bone density and/or to vitamin D receptor (VDR) gene polymorphisms. We analyzed 319 digital panoramic radiographs from the same number of patients. Alveolar bone level was expressed as percentage of root length. The mandibular cortical width index was calculated as a measure of mandibular bone density, and, in 72 randomly selected cases, the haplotype of the VDR gene (BsmL) was determined by polymerase chain reaction. Alveolar bone level was not related to the mandibular cortical width index (p = 0.568) or VDR gene expression (p = 0.575). Bone loss was greater in smokers than in non-smokers (p = 0.036), and the mandibular cortical width index was higher in males (p = 0.04), the older age group (p = 0.032), and in those with more teeth (p = 0.01). Multivariate analysis confirmed the association between these variables and alveolar bone loss. Alveolar bone loss showed no significant relationship with the mandibular bone density evaluated on digital panoramic radiographs or with VDR genotype (BsmL) in Caucasian females and males aged under 47 years.

Radiographic study of the mandibular retromolar canal: an anatomic structure with clinical importance.

INTRODUCTION: The retromolar canal is an anatomic structure of the mandible with clinical importance. This canal branches off from the mandibular canal behind the third molar and travels to the retromolar foramen in the retromolar fossa. The retromolar canal might conduct accessory innervation to the mandibular molars or contain an aberrant buccal nerve. METHODS: Patients referred for panoramic radiography were consecutively enrolled, provided a limited cone-beam computed tomography (CBCT) scan had also been taken in the area of interest. Radiographs were retrospectively screened for the presence of a retromolar canal, and linear measurements (distance to second molar, height, width) were taken. RESULTS: One hundred twenty-one sides in 100 patients were evaluated (100 unilateral and 21 bilateral cases). A total of 31 retromolar canals were identified with CBCT (25.6%). Only 7 of these canals were also seen on the corresponding panoramic radiographs. The existence of a retromolar canal was not statistically related to gender or side. With regard to the linear measurements, the mean distance from the retromolar canal to the second molar was 15.16 mm (±2.39 mm), the mean height of the canal was 11.34 mm (±2.36 mm), and the mean width was 0.99 mm (±0.31 mm). CONCLUSIONS: This radiographic study documents a frequency of 25% for the presence of a retromolar canal. The clinician is advised to preserve this anatomic variation when performing surgery in the retromolar area and to consider additional locoregional anesthesia in the case of failed mandibular block anesthesia.

Surgical endodontic management of an invasive cervical resorption class 4 with mineral trioxide aggregate: a 6-year follow-up.

Invasive cervical resorption is a type of external resorption rarely seen as an adverse effect after a guided tissue regeneration procedure for a periodontal condition. This case report summarizes the surgical endodontic management of an invasive cervical resorption class 4 (Heithersay) with mineral trioxide aggregate, in a mandibular incisor of a 67-year-old man. A 6-year clinical follow-up with radiovisiography and cone-beam computerized tomography revealed complete healing. A surgical endodontic management could promote healing and survival of a tooth with advanced root resorption due to a periodontal condition.