The surgical anatomy of the inferior alveolar nerve: a meta-analysis with clinical implications.

BACKGROUND: The main goal of the present meta-analysis was to provide physicians, especially surgeons, with crucial data on the complete anatomy of the inferior alveolar nerve (IAN). It is hoped that our results may help reduce the rates of complications in procedures associated with this anatomical entity. MATERIALS AND METHODS: Major online medical databases such as PubMed, Embase, Scopus, Web of Science, Google Scholar, and Cochrane Library were searched to gather all studies on IAN anatomy, including topography, morphology, and variations. RESULTS: IAN mean thickness of the IAN in the mandibular angle area was set to 2.32 mm (LL: 1.82 ; HL: 2.78-). IAN mean thickness of the IAN in the mandibular body region was found to be 2.49 mm (LL: 2.02 ; HL: 2.98). The mean thickness of the IAN in the mental region was established at 1.70 mm (LL: 1.54 ; HL: 1.86). The mean distance from the IAN to the external (buccal) surface of the 1st molar was set to be 4.99 mm (LL: 3.84 ; HL: 6.13). CONCLUSIONS: In conclusion, this is the most up-to-date and thorough analysis of the complete anatomy of the IAN. We provided morphometric data that present the spatial relationship of the IAN with numerous anatomical landmarks in the mandibular region. These include the ramus of the mandible, the first, second, and third molars, and the body of the mandible, among others. It is hoped that the results of the present meta-analysis may be a helpful tool for physicians, especially surgeons, performing various oral and maxillofacial procedures, such as third molar removal or IAN block anesthesia.

Incorporation of the sphenoid sinuses' septum / septa in the carotid canal - evaluation before the FESS.

The purpose of the research was to define the frequency prevalence of the incorporation of sphenoid sinuses' septum / septa in the carotid canal of the adult population. MATERIALS AND METHODS: 296 computed tomography (CT) scans of the patients (147 females, 149 males), who did not present any pathology in the sphenoid sinuses, were evaluated in this retrospective analysis. Spiral CT scanner - Siemens Somatom Sensation 16 - was used to glean the medical images. Standard procedure applied in the option Siemens CARE Dose 4D. No contrast medium was administered. Multiplans reconstruction (MPR) tool was used in order to obtain frontal and sagittal planes from the transverse planes previously received. RESULTS: Bilateral incorporation of the main septum (MS) in the carotid canal was not present in any of the patients, whereas unilateral incorporation was noticed in 21.96% of the patients (17.68% females, 26.17% males). On the right side it occurred in 11.82% of cases (10.88% females, 12.75% males), and on the left side in 10.14% of cases (6.8% females, 13.42% males). Bilateral incorporation of the additional septum (AS) was found in 8.45% of the patients (4.08% females, 12.75% males), whereas unilateral incorporation was noted in 28.37% of the patients. It was seen on the right side in 11.82% of cases (12.93% females, 10.74% males), and on the left side in 16.55% cases (15.65% females, 17.45% males). The most common variant was the incorporation of only one of the septa (either the MS or the AS) in the wall of the carotid canal unilaterally. Such situation took place in 30.07% of the patients (29.25% females, 30.87% males). Incorporation of two septa on the same side was noticed in 4.39% of cases (4.08% females, 4.7% males), and incorporation of three septa in 0.34% of cases (0.7% males). CONCLUSIONS: The anatomy of the paranasal sinuses is varied to a great extent, hence performing a CT scan is crucial before the scheduled surgery, as it may lessen the unforeseeable surgical complications, that may result from the high prevalence of variants in the sinuses.

A micro-computed tomographic (micro-CT) analysis of the root canal morphology of maxillary third molar teeth.

INTRODUCTION: The aim of this study was to analyze the root canal morphology of maxillary third molars (MTMs) using micro-computed tomography (micro-CT). MATERIALS AND METHODS: Seventy-eight consecutively-extracted human MTMs were scanned using micro-CT (spatial resolution=13.68µm per pixel). Dedicated software (SkyScan®) was used to create virtual reconstructions and perform 3D-analysis. A range of anatomical features were assessed; externally (root number, length, fusion, curvature, apex), within the pulp chamber (distance between canal orifices, floor thickness) and within the root canal system (root canal number, classification, ramifications, isthmuses, apical constriction). RESULTS: The donor age ranged from 19 to 73 years (mean±SD 32.3±16.5years). MTMs possessed one or three roots, which principally curved buccally/palatally (75.9%), had 1-4 root canals and typically no apical constriction (84.4%). The average external root length was 11.89±1.53mm, while root canal length was 10.18±0.35mm. The root canal diameter 1mm from the apex was 0.37±0.23mm and negatively correlated with donor's age (r=-0.76; p=0.01), while pulp chamber thickness positively correlated with age (r=0.58; p=0.035). Significantly, furcation canals, canal loops and root canal calcifications were sporadic findings. CONCLUSIONS: In some cases the anatomy of MTMs may not be as complicated as previously documented, being similar to the reported anatomy of other maxillary molars. During root canal treatment of MTMs, the frequent deviation of the apical foramen from the radiographic apex should be considered, as should the absence of an apical constriction in the majority of cases. In addition, buccal/palatal root curvature, often undiagnosed radiographically, is the most common root curvature in MTMs.

Validation of the intervertebral disc histological degeneration score in cervical intervertebral discs and their end plates.

BACKGROUND CONTEXT: Vertebral joints consist of intervertebral discs (IVDs) and cartilaginous end plates (EP) that lie superiorly and inferiorly to the IVDs and separate them from the adjacent vertebral bodies. With aging, both IVDs and EPs undergo degeneration. The Histologic Degeneration Score (HDS) is a grading system that microscopically evaluates the degree of degeneration in lumbar discs and predicts it with high accuracy basing on several histological markers of IVD and EP. There is currently a lack of validated histologic grading schemes for cervical spine degeneration. PURPOSE: The aim of our study was to describe the changes in cervical IVDs and EPs with degeneration and to test the validity of the HDS in the cervical spine. STUDY DESIGN: A histological study on degenerative changes in cervical IVDs and EPs was conducted. METHODS: Thirty human cadavers were dissected to obtain 60 cervical IVDs from the lower half of C4 to the level of the upper half of C6. The IVDs were carefully excised along with EPs and then sectioned to obtain midsagittal samples for macroscopic examination according to a five-grade classification system. The samples were further dissected, fixed, and stained for histological examination according to HDS. RESULTS: Thirty C4-C5 IVDs and thirty C5-C6 IVDs were macroscopically examined for degeneration. The averaged Thompson's grade was found to be 2.9±1.3. The mean HDS for IVDs was 13.1±5.8 and for EP was 10.2±5.2. The interrater reliability estimates indicated excellent reliability (κ values>0.81, percentage agreement 86.1%-96.1%). Spearman's rank correlation coefficients for IVD and EP scores showed good consistency in predicting macroscopic degeneration. No significant differences were found between the values for cervical IVDs and EPs in the present study and those for lumbar discs derived in previous studies. CONCLUSIONS: The HDS was confirmed to be as accurate in predicting the degree of degeneration in the cervical spine as in the lumbar region. To our best knowledge, this is the first reported and validated histological classification system intended for assessing histological degeneration in the cervical spine. Therefore, HDS can be recommended for academic and pathologic purposes in cervical disc degeneration.

Validation of the Polish version of the EORTC Head and Neck module (QLQ-H&N35).

AIM: The aim of this study was to psychometrically validate the EORTC translated, Polish version of the EORTC QLQ-H&N35 questionnaire to support using it in the Polish clinical setting in patients with head and neck malignancies. MATERIALS AND METHODS: Patients with histologically confirmed head and neck malignancies were included in the study. All patients filled in the Polish version of the EORTC QLQ-C30, the EORTC QLQ-H&N35 module, and a demographic questionnaire. Standardized validity and reliability analyses were performed. RESULTS: During the recruitment period a total of 176 patients (82 females - 46.6%) were enrolled into the study, with a mean age of 54.3 ± 11.2 years. Cronbach alpha values ranged from 0.71 to 0.87. Satisfactory convergent and discriminant validity in multi-trait scaling analyses was seen. CONCLUSIONS: The Polish version of the EORTC QLQ-H&N35 module is a reliable and valid tool for measuring HRQoL in Polish patients with head and neck malignancies. It can be fully recommended for use in the Polish clinical setting.

Age- and degeneration-related variations in cell density and glycosaminoglycan content in the human cervical intervertebral disc and its endplates.

The first aim of this study was to quantify cell density in cervical intervertebral discs (IVDs) and endplates of varying age and degeneration grade. The second aim was to analyze glycosaminoglycan (GAG) content in cervical IVDs and their endplates. Sixty cervical IVDs were excised from 30 human cadavers, not later than 24 hours post-mortem. Each sample underwent sectioning. Half of each sample underwent GAG content analysis using the dimethylmethylene blue binding assay. The other half underwent histological processing, histological degeneration grading, and cell density assessment using the Abercrombie method. The nucleus pulposus (NP) (4218 ± 417 cells/mm³) had significantly higher cell density than the anterior annulus fibrosus (AF) (3283 ± 438 cells/mm³; p < 0.0001), and similar cell density (4464 ± 551 cells/mm³; p = 0.36) to the posterior AF. Cell density was similar throughout the different regions of the endplate. The NP (619 ± 178 µg/mg dry weight) had a significantly higher GAG content than both the anterior (428 ± 199 µg/mg dry weight; p < 0.0001) and posterior AF (524 ± 218 µg/mg dry weight; p < 0.0001). In conclusion, this study introduces detailed 3D maps of cervical IVD and endplate cell density and GAG content. Furthermore, it shows that cervical IVDs and their endplates only slightly differ, in terms of cell density and GAG content, from lumbar IVDs.

Mandible - clinically revisited.

Based on the current literature authors revised anatomical and clinical datas considering the mandible.

Controversies on the position of the mandibular foramen - review of the literature.

Foramen of mandible is the most important point considering the Halsted anesthesia. Position of this foramen seems to be stable, however there are lots of controversies regarded to its position. Based on the current literature authors revised datas from literature considering the location of the mandibular foramen.

Anatomy of the pterygomandibular space - clinical implication and review.

AIM: The aim of this study was to present review of the pterygomandibular space with some referrals to clinical practice, specially to the methods of lower teeth anesthesia. CONCLUSIONS: Pterygomandibular space is a clinically important region which is commonly missing in anatomical textbooks. More attention should be paid to it both from theoretical and practical point of view, especially in teaching the students of first year of dental studies.