Metastasis of small cell lung cancer to bilateral extraocular muscles: a case report.

BACKGROUND: Orbital metastasis is a possible complication of small cell lung cancer and a pattern of bilateral invasion of the extraocular muscles has rarely been reported in literature. CASE PRESENTATION: A 46-year-old white male with a past medical history of smoking and stage IV small cell lung carcinoma presented with loss of vision and pain in the left eye. Examination revealed bilateral proptosis and left afferent pupillary defect, and visual acuity was hand motion on the left eye and 4/10 on the right eye. An orbital computed tomography scan showed a compression of the left optic nerve between the extraocular muscles at the apex, and a lateral canthotomy was performed for a new-onset compressive optic neuropathy, with residual visual improvement. There was also significant enlargement of the extraocular muscles in the right orbit. The patient was maintained in palliative treatment with both chemotherapy and local medical and surgical (amniotic membrane cover for exposure keratopathy) ophthalmological treatments until he eventually died 5 months after. CONCLUSION: Bilateral metastasis to the extraocular muscles is a very rare manifestation of small cell lung cancer and the palliative treatment in these cases is challenging.

Giant Conjunctival Cyst of the Orbit in a Patient with Previous Enucleation.

Introduction: Conjunctival cysts of the orbit development are a rare complication in enucleated patients. They result from the entrapment of conjunctival epithelium within the orbit. Case Presentation: We report the case of a 25-year-old man with a history of enucleation for a retinoblastoma of the right eye who presented with difficulty in fitting his eye prothesis. On his past medical records, there was no reference to the placement of any orbital implant at the time of the surgery. Biomicroscopy of the right eye revealed a thickened bulbar conjunctiva, an inferior symblepharon, and a translucid central area with vascularization. Imaging was remarkable for a cystic cavity filling the whole right orbit. Biopsy revealed the diagnosis of a conjunctival cyst, and drainage was performed, alleviating the patient's symptoms. Conclusion: Orbital conjunctival cysts may pose a clinical problem, and treatment modalities include surgical excision, absolute alcohol injection, and trichloroacetic acid injection.

Inhibitors of Transthyretin Amyloidosis: How to Rank Drug Candidates Using X-ray Crystallography Data.

Amyloidosis is a group of protein misfolding diseases, which include spongiform encephalopathies, Alzheimer's disease and transthyretin (TTR) amyloidosis; all of them are characterized by extracellular deposits of an insoluble fibrillar protein. TTR amyloidosis is a highly debilitating and life-threatening disease. Patients carry less stable TTR homotetramers that are prone to dissociation into non-native monomers, which in turn rapidly self-assemble into oligomers and, ultimately, amyloid fibrils. Liver transplantation to induce the production of wild-type TTR was the only therapeutic strategy until recently. A promising approach to ameliorate transthyretin (TTR) amyloidosis is based on the so-called TTR kinetic stabilizers. More than 1000 TTR stabilizers have already been tested by many research groups, but the diversity of experimental techniques and conditions used hampers an objective prioritization of the compounds. One of the most reliable and unambiguous techniques applied to determine the structures of the TTR/drug complexes is X-ray diffraction. Most of the potential inhibitors bind in the TTR channel and the crystal structures reveal the atomic details of the interaction between the protein and the compound. Here we suggest that the stabilization effect is associated with a compaction of the quaternary structure of the protein and propose a scoring function to rank drugs based on X-ray crystallography data.

Relationship between soft tissue dimensions and tomographic radial root position classification system for immediate implant installation.

The aim of this study was to evaluate the relationship between soft tissue dimensions and radial root position (RRP) classification for immediate implant placement on maxillary anterior teeth. Maxillary anterior teeth (n = 420) were analyzed in the radial plane of cone beam computed tomography (CBCT) scans. Each tooth was classified according to its RRP: class I, (IA, IB); class II (IIA, IIB) class III; class IV, and class V. Soft tissue thickness at different landmarks, supracrestal soft tissue height, and crestal bone thickness were measured in CBCT. Keratinized tissue width was clinically measured. Gingival phenotype (thick or thin) was evaluated by transparency of the periodontal probe and at the landmark 2 mm from the gingival margin in CBCT. Class I tooth position accounted for 31.7%, class II for 45%, class III for 13.3%, class IV for 0.5%, and class V for 9.5%. The gingival phenotype was associated with RRP (χ2 test, p < 0.05). Soft tissue dimensions were significantly different over RRP classes (ANOVA and Tukey tests, p < 0.05). Types IA and IIA presented both thick soft and hard tissues. When planning immediate implants in the anterior maxilla, soft tissue dimensions evaluation should be incorporated into RRP classification to increase the accuracy and predictability of treatment outcomes.

Hot-wiring dynein-2 establishes roles for IFT-A in retrograde train assembly and motility.

Intraflagellar transport (IFT) trains, built around IFT-A and IFT-B complexes, are carried by opposing motors to import and export ciliary cargo. While transported by kinesin-2 on anterograde IFT trains, the dynein-2 motor adopts an autoinhibitory conformation until it needs to be activated at the ciliary tip to power retrograde IFT. Growing evidence has linked the IFT-A complex to retrograde IFT; however, its roles in this process remain unknown. Here, we use CRISPR-Cas9-mediated genome editing to disable the dynein-2 autoinhibition mechanism in Caenorhabditis elegans and assess its impact on IFT with high-resolution live imaging and photobleaching analyses. Remarkably, this dynein-2 "hot-wiring" approach reignites retrograde motility inside IFT-A-deficient cilia without triggering tug-of-war events. In addition to providing functional evidence that multiple mechanisms maintain dynein-2 inhibited during anterograde IFT, our data establish key roles for IFT-A in mediating motor-train coupling during IFT turnaround, promoting retrograde IFT initiation, and modulating dynein-2 retrograde motility.

Correlation of gingival stippling with periodontal phenotypical features: A cross-sectional study.

This study aimed at determining the correlation between gingival stippling (GS) and other phenotypical characteristics. Adult subjects in need of cone-beam computed tomography scans (CBCT) and comprehensive dental treatment in the maxillary anterior region were recruited. Facial gingival thickness [GT] and buccal bone thickness [BT] were assessed utilizing CBCT. Standardized intraoral photographs were obtained to determine keratinized tissue width (KTW), presence of GS in all facial and interproximal areas between the maxillary canines, and other variables of interest, such as gingival architecture (GA), tooth shape, and location. Statistical analyses to assess different correlations among recorded variables were conducted. A total of 100 participants and 600 maxillary anterior teeth constituted the study population and sample, respectively. Facial GS was observed in 56% of males and 44% of females, and it was more frequently associated with flat GA, triangular and square/tapered teeth, central incisors, and males. Greater mean values of GT, BT, and KTW were observed in facial areas that exhibited GS. Interdental GS was present in 73% of the sites and it was more frequently observed in males, the central incisor region, and when facial GS was present. Multilevel logistic regression revealed a statistically significant association between the presence of GS and KTW, BT measured at 3mm apical to the bone crest, and tooth type. This information can be used in the recognition of common periodontal phenotypical patterns associated with specific features of great clinical significance.

Pilot Study on Newborn Screening for Spinal Muscular Atrophy.

INTRODUCTION: Newborn screening (NBS) in Portugal is a significant public health measure to provide early detection for specific disorders so that early treatment is possible. Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder that causes degeneration of anterior horn cells in the human spinal cord and subsequent loss of motor neurons. Its incidence is estimated in 1.6000-11.800 live births. A pilot study on 100.000 newborns is being carried out at the neonatal screening laboratory with the aim of determining the specificity, sensitivity, and feasibility of the SMA screening at the NBS laboratory in Portugal. METHODS: The study presented here was based on data obtained from neonatal screening, involving the analysis of 25.000 newborns. SMA screening is performed by a qualitative detection of exon 7 of the SMN1 gene. The assay was performed using a commercially available real-time PCR, the Eonis SMN1, TREC, and KREC kit. RESULTS/CASE REPORT: The dried blood spots of a total of 25.000 newborns were tested; among these newborns, two were diagnosed as having SMA with survival motor neuron 1 (SMN1) deletion. These two SMA-positive samples were sent to a specialized clinical centre and a peripheral blood sample was sent to the reference laboratory for confirmation of the exon 7 deletion and determination of the SMN2 copy number. CONCLUSION: Early diagnosis and intervention are important for SMA treatment to be effective; the treatment should be started at the pre-symptomatic stage of SMA. Thus, newborn screening for SMA is strongly recommended. Currently, targeted therapies for SMA are available, and attempts are being made worldwide to include SMA screening in newborns.

Non-invasive assessment of peri-implant mucosal thickness: A cross-sectional study.

BACKGROUND: This study aimed to evaluate the reliability and reproducibility of different non-invasive methods for the assessment of peri-implant mucosal thickness. METHODS: Subjects with two adjacent dental implants in the central maxillary region were included in this study. Three different methods to assess facial mucosal thickness (FMT) were compared: digital file superimposition using Digital Imaging and Communication in Medicine (DICOM) and stereolithography (STL) files of the arch of interest (DICOM-STL), DICOM files alone, and non-ionizing ultrasound (US). Inter-rater reliability agreements between different assessment methods were analyzed using inter-class correlation coefficients (ICCs). RESULTS: A total of 50 subjects with 100 bone-level implants constituted the study population. Assessment of FMT using STL and DICOM files demonstrated excellent inter-rater reliability agreement. Mean ICC values of 0.97 and 0.95 were observed in the DICOM-STL and DICOM groups, respectively. Comparison between the DICOM-STL and US revealed good agreement, with an ICC of 0.82 (95% CI: 0.74 to 0.88) and a mean difference of -0.13 ± 0.50 mm (-1.13 to 0.86). Comparison between DICOM files alone versus US showed good agreement, with an ICC of 0.81 (95% CI: 0.73 to 0.89) and a mean difference of -0.23 ± 0.46 mm (-1.12 to 0.67). Comparison between DICOM-STL and DICOM files revealed excellent agreement, with an ICC of 0.94 (95% CI: 0.91 to 0.96) and a mean difference of 0.1 ± 0.29 mm (LOA -0.47 to 0.46). CONCLUSIONS: Quantification of peri-implant mucosal thickness via analysis of DICOM-STL files, DICOM files, or US assessment are comparably reliable and reproducible methods.

Altered Brain Expression of DNA Methylation and Hydroxymethylation Epigenetic Enzymes in a Rat Model of Neuropathic Pain.

The role of epigenetics in chronic pain at the supraspinal level is yet to be fully characterized. DNA histone methylation is crucially regulated by de novo methyltransferases (DNMT1-3) and ten-eleven translocation dioxygenases (TET1-3). Evidence has shown that methylation markers are altered in different CNS regions related to nociception, namely the dorsal root ganglia, the spinal cord, and different brain areas. Decreased global methylation was found in the DRG, the prefrontal cortex, and the amygdala, which was associated with decreased DNMT1/3a expression. In contrast, increased methylation levels and mRNA levels of TET1 and TET3 were linked to augmented pain hypersensitivity and allodynia in inflammatory and neuropathic pain models. Since epigenetic mechanisms may be responsible for the regulation and coordination of various transcriptional modifications described in chronic pain states, with this study, we aimed to evaluate the functional role of TET1-3 and DNMT1/3a genes in neuropathic pain in several brain areas. In a spared nerve injury rat model of neuropathic pain, 21 days after surgery, we found increased TET1 expression in the medial prefrontal cortex and decreased expression in the caudate-putamen and the amygdala; TET2 was upregulated in the medial thalamus; TET3 mRNA levels were reduced in the medial prefrontal cortex and the caudate-putamen; and DNMT1 was downregulated in the caudate-putamen and the medial thalamus. No statistically significant changes in expression were observed with DNMT3a. Our results suggest a complex functional role for these genes in different brain areas in the context of neuropathic pain. The notion of DNA methylation and hydroxymethylation being cell-type specific and not tissue specific, as well as the possibility of chronologically differential gene expression after the establishment of neuropathic or inflammatory pain models, ought to be addressed in future studies.

Vitamin D status in active duty Navy military personnel: a systematic review.

OBJECTIVES: Active duty Navy military personnel are prone to vitamin D deficiency due to an occupational environment detrimental to sunlight exposure. The main objective of this systematic review is to provide a worldwide overview of vitamin D status in this population. METHODS: The Condition, Context, Population (CoCoPop) mnemonic was used to define the inclusion criteria (vitamin D status; all contexts; active duty Navy military personnel). Studies with recruits or veterans were excluded. Scopus, Web of Science and PubMed/Medline databases were searched from inception to 30 June 2022. Joanna Briggs Institute and Downs & Black checklists were used for quality assessment and data were synthesised in narrative and tabular formats. RESULTS: Thirteen studies published between 1975 and 2022 and conducted in northern hemisphere Navies, including mainly young and male service members, were included. The prevalence of vitamin D deficiency was globally reported as significant. Nine studies included a total of 305 male submariners who performed 30-92 days submarine patrol and reported the effect of sunlight deprivation in the decrease of vitamin D levels. CONCLUSIONS: This new systematic review underlines the high prevalence of vitamin D deficiency in the Navy, especially in submariners, and the need to implement measures to prevent vitamin D deficiency. Serum 25(OH)D data available and the heterogeneity of the studies limited a pooled analysis. Most studies included only submariners, which may limit generalisability to all active duty Navy military personnel. Further research on this topic should be promoted. PROSPERO REGISTRATION NUMBER: CRD42022287057.

Relationship between supracrestal soft tissue dimensions and other periodontal phenotypic features: A cross-sectional study.

BACKGROUND: The purpose of this study was to determine the association between periodontal supracrestal soft tissue dimensions (PSSTDs) and other phenotypic features in non-molar maxillary teeth. MATERIALS AND METHODS: Adult subjects in need of comprehensive dental treatment were recruited. Periodontal phenotypic variables (i.e., facial and palatal gingival thickness [GT], alveolar bone thickness [BT], and PSSTDs, namely distance from the gingival margin to the bone crest defined as periodontal supracrestal tissue height [PSTH] and distance from the cementoenamel junction to the bone crest [CEJ-BC]) were recorded using cone-beam computed tomography scans. Standardized intraoral photographs were obtained to assess facial keratinized tissue width (KTW) and other anatomical parameters (i.e., tooth type, gingival architecture, and interproximal papilla height). RESULTS: The study sample was constituted of 87 participants that contributed with a total of 522 maxillary anterior teeth. Differences in mean values of PSSTDs, KTW, GT, and BT were observed between tooth types and sex. Males exhibited a thicker GT and BT, and taller PSTH and KTW compared to females. Shorter CEJ-BC was associated with shorter PSTH, wider KTW, and thicker GT and BT. Shorter PSTH was associated with thicker facial BT. Notably, BT and GT were positively correlated at both facial and palatal sites, meaning that the thicker the gingival phenotype, the thicker the bone morphotype. Facial BT and facial GT were positively correlated with KTW. A flat gingival architecture was associated with the thick periodontal phenotype. Square teeth had shorter CEJ-BC, wider KTW, and thicker GT. CONCLUSIONS: Periodontal phenotypic features vary across and within subjects, between facial and palatal sites at different apico-coronal levels, and as a function of sex and tooth type. The shorter the PSSTDs, the wider the KTW and the thicker the GT and BT. PSSTDs, particularly PSTH, should be considered an integral component of the periodontal phenotype.

Current landmarks for gingival thickness evaluation in maxillary anterior teeth: a systematic review.

OBJECTIVES: To identify and report the current landmarks used for measuring gingival thickness (GT) in healthy maxillary anterior teeth. MATERIAL AND METHODS: The protocol of this Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) 2020-compliant systematic review was registered in PROSPERO. A literature search was conducted to identify articles that met the eligibility criteria published up to 2022. The methods of assessing gingival thickness and the landmarks adopted on the studies were described. Primary outcomes were identified, and the frequency of reporting in the selected articles was calculated. Additionally, risk-of-bias assessments were performed for individual articles. RESULTS: Fifty-eight articles (34 with low risk of bias and 24 with medium risk of bias) were selected. A total of 3638 individuals had their gingival thickness measured. Thirty-nine different landmarks were adopted in the studies. Fifty-six articles with 22 landmarks were included in the meta-analysis. A higher heterogeneity was found between the studies (GT ranged from 0.48 to 2.59 mm, mean GT 1.074; 95% CI: 1.024-1.104). The 3 most used landmarks were 2 mm from gingival margin (10 studies, mean GT 1.170 mm, 95% CI: 1.085-1.254), bone crest (9 studies, mean GT 1.01 mm; 95% CI: 0.937-1.083), and cemento-enamel junction (7 studies, mean GT 1.172 mm; 95% CI: 1.105, 1.239). CONCLUSIONS: Within the limits of this study, a large heterogeneity in GT was found, and there was no consensus on the ideal landmark for GT measurement. CLINICAL RELEVANCE: The landmark 2 mm from gingival margin, located at attached gingiva, can be used for GT measurement by clinical and image-based devices. This is an important step for a quantitative instead of a qualitative evaluation of phenotypes.

The relationship between tomographic sagittal root position of maxillary anterior teeth and the bone housing.

STATEMENT OF PROBLEM: In a prosthetically driven treatment plan, the tomographic sagittal root position in relation to the bone housing is an important factor in the decision-making process for immediate implant placement. However, other important parameters must be considered in the bone housing of each tooth, including the alveolar ridge dimensions, the buccal and the palatal bone thickness, and the root dimensions. PURPOSE: The purpose of this clinical study was to evaluate the relationship between the sagittal root position of maxillary anterior teeth and the bone housing. MATERIALS AND METHODS: A total of 420 maxillary anterior teeth were analyzed in 70 participants. The tomographic scans were classified as sagittal root position classes I, II, III, and IV. Measurements included buccal and palatal bone thickness, alveolar ridge height, alveolar ridge width, apical bone height, root length, and root width. The Pearson correlation, ANOVA, and Tukey post hoc tests were used to determine statistically significant differences (α=0.05). RESULTS: The sagittal root position distribution was 65.2%, 9.3%, 0.7%, and 24.8% for classes I, II, III, and IV, respectively. Bone housing measurements were significantly different in relation to the 4 sagittal root position classes (P<.05), except for alveolar ridge height. Post hoc analysis showed that, in class I, buccal bone thickness and alveolar bone height were significantly low, whereas root length and palatal bone thickness were high. The higher buccal bone thickness was found in class II, and lower alveolar ridge width and palatal bone thickness in class IV. These measurements in tooth groups were also significantly different over the sagittal root position classes (P<.05). The buccal bone thickness, palatal bone thickness, and alveolar ridge width presented different levels of correlation with alveolar ridge width over the sagittal root position classes. The buccal bone thickness and palatal bone thickness were weakly correlated in class I (r=0.163) and IV (r=0.222). CONCLUSIONS: Bone housing measurements were significantly different in relation to the sagittal root position of maxillary anterior teeth.

Relationship between smile type and periodontal phenotype: A clinical and tomographic cross-sectional study.

OBJECTIVES: To evaluate the correlation between smile type (ST) and the periodontal phenotype (PP). MATERIAL AND METHODS: Clinical and photographic examinations of 164 participants (48 men and 116 women, mean age 22.9 ± 4.6 years) were performed, including an evaluation of ST (high, average, and low), gingival phenotype (GP) by transparency of the periodontal probe (TRAN), keratinized tissue width (KTW), gingival architecture (GA), tooth shape (TS), and papilla height (PH). A subgroup of 70 participants underwent soft-tissue cone-beam tomographic examinations (ST-CBCT), in which GP, gingival thickness (GT), buccal bone thickness (BBT), and the distances from the gingival margin and cementoenamel junction to the buccal bone crest (GM-BBC and CEJ-BBC) were evaluated. The data were analyzed using one-way ANOVA, Student's t-test, and chi-square tests, with the level of significance set at 0.05. RESULTS: High, average, and low STs were found in 31.7%, 56.7%, and 11.6% of the participants, respectively. Sex (p=0.001), GP evaluated using TRAN (p=0.021) and ST-CBCT scans (p=0.009), GA (p<0.001), and TS (p=0.001), were associated with STs. The prevalence of thin GP was: 63% in low, 50% in average, and 38% in high smile types. KTW (p=0.004), PH (p<0.001), GT at different landmarks (p<0.05), CEJ-BBC (p=0.017), and GM-BBC (p=0.001) were significantly different among STs. The highest GT and KTW were found in the high-smile group, average-smile presented the higher CEJ-BBC while GM-BBC and PH, were higher in low-smile group. CONCLUSION: Periodontal phenotype components presented important difference over the smile types. CLINICAL RELEVANCE: A detailed examination of smile types is an essential part of treatment planning, especially when the patient has high esthetic demands. Clinical and tomographic individual analysis of periodontal phenotypes over the smile types may be helpful for a case-by-case approach, and for the development of well-defined treatment protocols.

Vitamin D status in the active duty Navy military personnel: protocol for a systematic review.

INTRODUCTION: Vitamin D is critical for bone health and its deficiency has been linked to increased incidence and severity of multiple diseases. Even so, vitamin D inadequacy is a major public health problem worldwide. The main source of vitamin D is endogenous cutaneous synthesis through exposure to solar ultraviolet B radiation, which is influenced by several factors, including occupational. The active duty Navy military personnel may be prone to vitamin D inadequacy, but a worldwide overview of vitamin D status in this specific population is still lacking. METHODS AND ANALYSIS: The CoCoPop mnemonic will be used for determining the inclusion criteria. Scopus, Web of Science and PubMed/Medline will be searched for all studies including 25-hydroxyvitamin D concentrations of the active duty Navy military personnel. Data extraction and quality assessment (Joanna Briggs Institute's and Downs and Black checklists) will be performed by two reviewers and data will be synthesised in narrative, tabular and map formats. ETHICS AND DISSEMINATION: This study will not involve human or animal subjects and, thus, does not require ethics approval. The outcomes will be disseminated via publication in a peer-reviewed scientific journal and presentation at a scientific conference. PROSPERO REGISTRATION NUMBER: CRD42022287057.

Gingival landmarks and cutting points for gingival phenotype determination: A clinical and tomographic cross-sectional study.

BACKGROUND: This cross-sectional study assessed the role of gingival landmarks (GLs) and cutting points (CPs) for gingival phenotype (GP) determination. METHODS: Six maxillary anterior teeth (70 subjects) were evaluated using soft tissue cone-beam computed tomography (ST-CBCT). Gingival thickness was measured at different GLs: 1) tissue zone (gingival margin [GM], 1 and 2 mm apical to GM, cemento-enamel junction, above the bone crest); 2) bone zone (buccal bone crest [BBC], 1, 2, and 3 mm apical to BBC). CPs of 0.6, 0.8, 1.0, 1.2, and 1.5 mm were used to discriminate between thin and thick GP. The clinical determination of GP was made based on transparency of the periodontal probe (TRAN). RESULTS: The prevalence of thin and thick GP depended on the GL and CP. Considering the CP (1 mm), thin GP at the tissue zone ranged from 99% at the GM to 10.2% above the bone crest. In the bone zone, thick GP ranged from 28% at the BBC to 6% at 3 mm apical to the BBC. The predictability of a correct assessment of GP by TRAN compared with ST-CBCT was influenced by the GLs and CPs. A slight agreement (kappa <0.2) and low accuracy (area under the curve <0.7) were found between methods. CONCLUSIONS: The determination of thin and thick GPs is related to the gingival landmarks and CPs. Further studies are required for a well-defined treatment protocol considering different gingival landmarks in tissue and bone zones. An ST-CBCT may be useful for this purpose.

Tomographic sagittal root position in relation to maxillary anterior bone housing in a Brazilian population.

Purpose: This cross-sectional study evaluated and categorized the tomographic sagittal root position (SRP) of the maxillary anterior teeth in a Brazilian population. Materials and Methods: Cone-beam computed tomographic scans of 420 maxillary anterior teeth of 70 patients (35 men and 35 women, mean age 25.2±5.9 years) were evaluated. The SRP was classified as class I, II, III, or IV. In class I, the root is positioned against the buccal cortical plate; in class II, the root is centered in the middle of the alveolar housing; in class III, the root is positioned against the palatal cortical plate; and in class IV, at least two-thirds of the root engage both the buccal and palatal cortical plates. Results: In total, 274 teeth (65.2%) were class I, 39 (9.3%) were class II, 3 (0.7%) were class III, and 104 (24.8%) were class IV. The frequency distribution over the teeth groups was different from the overall analysis. Important differences were found in the frequencies of classes I, II, and IV compared to other populations. Sex was not associated with the SRP classes (P=0.307). Age distribution was significantly different over the classes (P=0.004). Conclusion: The findings of this study on the distribution of SRP classes among the Brazilian population compared to other populations demonstrate that the SRP should be analyzed on a case-by-case basis for an accurate treatment plan in the maxillary anterior area.

Relationship between anterior maxillary tooth sagittal root position and periodontal phenotype: a clinical and tomographic study.

OBJECTIVES: To evaluate the relationship between the tomographic sagittal root position (SRP) of maxillary anterior teeth and periodontal phenotype (PP). MATERIAL AND METHODS: Seventy volunteers (420 teeth) were evaluated. Clinical and photographic exams included the evaluation of gingival phenotype (GP) by transparency of the periodontal probe, keratinized tissue width (KTW), gingival architecture, tooth shape, and papilla height (PH). Soft tissue tomographic scan (ST-CBCT) measurements included the SRP classification, GP, gingival thickness in the tissue zone (GT-TZ) and in the bone zone (GT-BZ), buccal bone thickness (BBT), and the distances from the gingival margin and from cementoenamel junction to the buccal bone crest (GM-BBC and CEJ-BBC). Kruskal-Wallis test and a linear regression analysis model were used. RESULTS: The frequency of SRP over the 420 teeth was 65.2% (class I), 9.3% (class II), 0.7% (class III), and 24.8% (class IV). Linear regression analysis showed that SRP is related to PP (p < 0.05). Significantly different measurements of PP parameters were found in SRP classes. The higher and lower GT and BBT were found in classes II and I, respectively. Class IV presented the highest KTW, PH, CEJ-BBC, and GM-BBC. Central incisors (CI) classes I and II were most frequently square-shaped, while 89% of CI Class IV were triangular-shaped. CONCLUSION: The SRP of maxillary anterior teeth is related to periodontal phenotype. CLINICAL RELEVANCE: Clinical and ST-CBCT individual analysis of PP and SRP may be helpful for an esthetic and functional treatment plan based on soft and hard tissue thickness and tooth positioning.

Micro-tomographic analysis of the root trunk and pre-furcation area of the first mandibular molars.

This study analyzed the root trunk (RT) and the pre-furcation area (PFA) of mandibular first molars. Thirty lower first mandibular molars extracted due to advanced periodontal disease were evaluated in a high-energy spiral computerized micro-tomography. Two gutta-percha markings on the cementoenamel junction (CEJ) and at the furcation entrance (FE) at buccal and lingual surfaces served as reference points for measurements of RT length, and PFA width and depth, at the levels of CEJ, 1 mm apical to CEJ, 2 mm apical to CEJ, and at the FE. The mean RT length was 2.49 mm at buccal and 3.18 mm at lingual sides. The mean widths of the PFA at CEJ, at 1 and 2 mm apical to CEJ, and at FE were 2.9, 3.4, 3.9 and 4.3 mm, respectively, while the mean depths were 0.19, 0.32, 0.57 and 1.1 mm, respectively. The PFA coincided with CEJ in 10 buccal and 10 lingual surfaces, representing 33.33% of the sample. There was a negative correlation between RT length and PFA dimensions. This study concludes that the RT length was smaller than previous studies. From the CEJ up to the furcation entrance, the PFA showed a progressive increase in width and depth. The coincidence of the PFA area beginning at the CEJ in 1/3, and the negative correlation between RT length and PFA dimensions may represent greater risk factor for the early development of furcation lesions.

WDR60-mediated dynein-2 loading into cilia powers retrograde IFT and transition zone crossing.

The dynein-2 motor complex drives retrograde intraflagellar transport (IFT), playing a pivotal role in the assembly and functions of cilia. However, the mechanisms that regulate dynein-2 motility remain poorly understood. Here, we identify the Caenorhabditis elegans WDR60 homologue, WDR-60, and dissect the roles of this intermediate chain using genome editing and live imaging of endogenous dynein-2/IFT components. We find that loss of WDR-60 impairs dynein-2 recruitment to cilia and its incorporation onto anterograde IFT trains, reducing retrograde motor availability at the ciliary tip. Consistent with this, we show that fewer dynein-2 motors power WDR-60-deficient retrograde IFT trains, which move at reduced velocities and fail to exit cilia, accumulating on the distal side of the transition zone. Remarkably, disrupting the transition zone's NPHP module almost fully restores ciliary exit of underpowered retrograde trains in wdr-60 mutants. This work establishes WDR-60 as a major contributor to IFT, and the NPHP module as a roadblock to dynein-2 passage through the transition zone.