Developing deep learning methods for classification of teeth in dental panoramic radiography.

OBJECTIVES: We aimed to develop an artificial intelligence-based clinical dental decision-support system using deep-learning methods to reduce diagnostic interpretation error and time and increase the effectiveness of dental treatment and classification. STUDY DESIGN: We compared the performance of 2 deep-learning methods, Faster Regions With the Convolutional Neural Networks (R-CNN) and You Only Look Once V4 (YOLO-V4), for tooth classification in dental panoramic radiography to determine which is more successful in terms of accuracy, time, and detection ability. Using a method based on deep-learning models trained on a semantic segmentation task, we analyzed 1200 panoramic radiographs selected retrospectively. In the classification process, our model identified 36 classes, including 32 teeth and 4 impacted teeth. RESULTS: The YOLO-V4 method achieved a mean 99.90% precision, 99.18% recall, and 99.54% F1 score. The Faster R-CNN method achieved a mean 93.67% precision, 90.79% recall, and 92.21% F1 score. Experimental evaluations showed that the YOLO-V4 method outperformed the Faster R-CNN method in terms of accuracy of predicted teeth in the tooth classification process, speed of tooth classification, and ability to detect impacted and erupted third molars. CONCLUSIONS: The YOLO-V4 method outperforms the Faster R-CNN method in terms of accuracy of tooth prediction, speed of detection, and ability to detect impacted third molars and erupted third molars. The proposed deep learning based methods can assist dentists in clinical decision making, save time, and reduce the negative effects of stress and fatigue in daily practice.

Evaluation of alterations in length and calcification of the styloid process in patients with end-stage renal failure.

OBJECTIVE: This study compared alterations in length and types of elongation and calcification of the styloid process (SP) between patients with end-stage renal failure (ESRF) who received renal transplantation, patients with ESRF undergoing dialysis, and a healthy control group. STUDY DESIGN: The SPs of 58 patients who had undergone renal transplants, 58 patients who received dialysis treatment, and 58 healthy individuals were examined with panoramic radiographs. Length measurements were made from the apex to the base of the SP. Elongation types were classified into 5 groups: normal, non-segmented, pseudo-segmented, segmented, and non-continuous. Calcification types were classified into 4 groups: external, partial, nodular, and complete. RESULTS: SP length was significantly greater in the renal transplantation and dialysis groups than in the control group (P < .001) and significantly longer in the renal transplantation group than in the dialysis group (P < .001). There was a significant difference between the groups regarding elongation types (P < .001), with the non-segmented type more frequent in the dialysis and renal transplant groups than in the control group. There was no significant difference in calcification types between groups (P = .225). Elongation and calcification types differed between sexes (P ≤ .008) CONCLUSIONS: Orofacial pain complaints in patients with ESRF should raise the suspicion of abnormal elongation and calcification of the SP, perhaps a manifestation of Eagle syndrome. It would be useful to evaluate the SPs of these patients clinically and radiographically.

Evaluation of trabecular changes following advancement genioplasty combined with or without bilateral sagittal split osteotomy by fractal analysis: a retrospective cohort study.

BACKGROUND: It is aimed to investigate whether there was a difference in radiographic changes in the operational areas between genioplasty alone and genioplasty combined with mandibular advancement and to evaluate the fractal dimension (FD) to assess trabecular changes after genioplasty surgery. METHODS: Preoperative-(T0) and postoperative-(T1) panoramic radiographs of 26 patients without any complications who underwent genioplasty combined with bilateral sagittal osteotomy and mandibular advancement or genioplasty alone were selected. In the panoramic radiographs of both groups, the genial segment, mandibular angulus, and surgical osteotomy line were examined using FD. The box-counting method was used for FD evaluation. RESULTS: It was determined that FD values before and after treatment were similar in both groups for all regions where measurements were made. After surgery, the FD values of the middle region of the genial segment were found to be significantly lower than the other regions. At T1, the FD values at the osteotomy area were found to be significantly higher than those in the middle region of the genial segment. CONCLUSION: Trabecular structure does not differ in patients undergoing genioplasty alone or in combination with mandibular advancement osteotomy. The middle region of the genial segment heals later than other regions.

Evaluation of the radiation protection effectiveness of a lead-free homopolymer in cone beam computed tomography.

OBJECTIVE: The objective was to compare the radiation protection effectiveness of a lead-free thermoplastic homopolymer (Anti-RAD) to conventional lead shielding in cone beam computed tomography (CBCT) exposures. STUDY DESIGN: Thermoluminescent dosimeters were placed on a human bone- and soft tissue-equivalent phantom to record equivalent doses in the thyroid gland, thyroid skin, and breast areas. CBCT images were obtained with the following 3 protocols: (1) without radiation shielding; (2) with 0.5-mm lead equivalent lead-containing shielding; and (3) with 0.5-mm lead equivalent Anti-RAD shielding. Independent t tests were used to evaluate the results. RESULTS: Compared with exposures without shielding, both lead and Anti-RAD protective devices reduced thyroid gland equivalent doses by approximately 40%, thyroid skin doses by approximately 75%, right breast skin doses by approximately 80%, and left breast skin doses by 75%. The differences in equivalent dose for both types of shielding compared with exposure with no shielding were statistically significant (P ≤ .042). However, there were no significant differences in dose reduction at any site between lead and Anti-RAD shielding (P ≥ .135). CONCLUSIONS: Radiation protection equivalent to lead can be provided with the Anti-RAD shield. With the use of this material, disadvantages such as damage to the aprons, lead toxicity, weight of lead aprons, and microbial contamination can be reduced.

A new perspective for radiologic findings of bruxism on dental panoramic radiography.

OBJECTIVE: This study aims to evaluate whether there is a relationship between the appositional classification in the mandible angle region and the mandibular cortical index (MCI) seen in bruxist individuals and to differentiate between the bruxist group without mandibular apposition and the non-bruxist group on panoramic radiographs. METHODS: The mandible angle region of 209 individuals, 170 bruxists and 39 non-bruxists, were included in the study. Each mandible angle apposition was classified as G0 (No directional change, no bone apposition)-G1 (Directional change on the basal cortex. No bone apposition)-G2 (Directional change plus generalized bone apposition with inhomogeneous surface)-G3 (Directional change plus localized bone apposition at one or more sites). The MCI of each individual was recorded according to their classified apposition. RESULTS: No statistically significant difference was found in the relationship between MCI and apposition severity in mandible angle grades in bruxist individuals (p = 0.063). A statistically significant difference was found between MCI and the bruxist G0/non-bruxist G0 groups (p < 0.001). While the MCI-C1 was higher in non-bruxist G0 individuals, the MCI-C2 was higher in bruxist G0 individuals. A statistically significant correlation was found between gender and severity of grades (p < 0.001). CONCLUSION: Although it is known that appositional changes are seen in the mandible angle region in bruxism, MCI can be used as a valuable radiologic diagnostic criterion during the evaluation of bruxist and healthy individuals in the G0 grade who have not yet radiologically demonstrated bone apposition in the mandible angle.

Evaluation of temporomandibular joint components and mandibular bone structure in ankylosing spondylitis patients.

OBJECTIVES: The study aimed to investigate the mandible and temporomandibular joint (TMJ) in patients with ankylosing spondylitis (AS) who had no signs or symptoms of TMJ-related disease and compare them with a control group. STUDY DESIGN: In total, 128 panoramic radiographs (63 patients with AS, 65 controls) were evaluated. Fractal analysis was conducted on the mandibular condyle (ROI1), angle of the mandible (ROI2), and the area adjacent to the mental foramen (ROI3). Articular eminence inclination (AEI) values were measured. Klemetti index (KI) evaluation of the mandibular cortex was also performed. RESULTS: Fractal dimension (FD) values were significantly lower in the patients with AS than the controls in ROI1 and ROI2 (P = .001), but there were no significant differences between groups for FD in ROI3, AEI, or KI (P ≥ .09). No significant differences were found in any parameters between patients with AS with different disease durations (P ≥ .06). CONCLUSIONS: Patients with AS displayed significantly lower FD values in condyles and the angle of the mandible and slightly lower AEI values; therefore, they should be examined routinely for TMJ disorders. Clinicians should be aware of the possibility of secondary osteoporosis in patients with AS and consider its probable effects on the mandible.

The evaluation of changes in maxillofacial bones using cone beam tomography in acromegaly

Background: The aim of the study was to evaluate the changes in craniofacial dimensions of newly diagnosed anduntreated acromegaly patients, patients with non-functional pituitary adenoma and healthy individuals on ConeBeam Computed Tomography (CBCT).Material and Methods: 50 newly diagnosed acromegaly patients who did not receive any treatment for acromegalywere included in the study (Group A). Twenty patients with nonfunctional pituitary adenoma (Group B) and 30healthy individuals were included (Group C). Linear, angular and volumetric measurements were performed.Results: Mandibular length showed significant difference in acromegaly patients, and maxillar length statisticallysignificant difference was found between the A-B and B-C (p> 0,05), no difference was found between the A-C(p<0,05). SNB and ANB angle was statistically different in all groups, while SNA angle was statistically different between group A-C and B-C. In volumetric measurements, a statistically significant difference was foundbetween groups a-c and groups A-B (p< 0,05), no difference was found between groups B-C (p>0,05).Conclusions: CBCT measurements showed that mandibular volume and length were increased in the acromegalygroup compared to the group B-C. Present study is the first research that compares acromegaly patients in respectto changes in maxillofacial dimensions. (AU)

Effects of conventional complete dentures and implant-supported overdentures on alveolar ridge height and mandibular bone structure: 2-year and 6-year follow-up study.

OBJECTIVES: The aim of this study was to compare the changes in mandibular bone structure in edentulous patients who were rehabilitated with conventional complete dentures (CCD) and implant supported overdentures (ISO), by evaluating alveolar bone loss (ABL), panoramic mandibular index (PMI), mandibular cortical width (MCW), gonion index (GI), antegonial index (AI), and articular eminence inclination (AEI). MATERIALS AND METHODS: Panoramic radiographs of 63 edentulous patients using CCD, 63 edentulous patients using ISO, and 126 patients without tooth loss were evaluated. Edentulous patients had a 2-year and 6-year follow-up panoramic radiograph image. ABL (anterior, premolar, and molar regions), MCW, PMI, AI, GI, and AEI were measured in each patient. Variation between measurements was analyzed using repeated measures ANOVA test and post hoc Tukey test. RESULTS: Both edentulous groups showed significantly lower mean than without tooth lost group in all measures (p < 0.000). ISO group showed significantly lower mean ABL than CCD group in anterior (p = 0.000), right premolar (p = 0.005), left premolar (p = 0.005), right molar (p < 0.000), and left premolar (p < 0.000) regions in short term. ISO group showed significantly lower mean ABL than CCD group in anterior (p = 0.021), right molar (p < 0.000), and left premolar (p < 0.000) regions in long-term. There is no statistically significant difference between the CCD and ISO groups in right premolar (p = 0.200) and left premolar (p = 0.134) regions in long term. Both edentulous groups showed significantly lower mean MCW (p < 0.000), PMI (p < 0.000), AI (p < 0.000), GI (p < 0.012), and AEI (p < 0.002) than the without tooth loss group. There is no statistically significant difference between the CCD and ISO groups in terms of changes in the mean MCW, PMI, AI, GI, and AEI measurement in short and long term (p > 0.000). CONCLUSIONS: In the short and long term, edentulism reduced alveolar crest height, MCW, and AEI in individuals, but had no effect on PMI, AI, or GI. The use of prosthesis did not prevent the decrease of alveolar crest height, MCW, or AEI (CCP or ISO). In the short and long term, however, ISO created less ABL in the mandibular anterior and molar regions than CCD. CLINICAL RELEVANCE: ABL cannot be halted in edentulous people, but by using ISO instead of CCD for rehabilitation, resorption can be reduced.

Clinical and radiological evaluation of dentomaxillofacial involvement in Type I Gaucher disease.

OBJECTIVES: This study aimed to evaluate the oral findings and dentomaxillofacial involvement of patients diagnosed with Type I Gaucher Disease (GD), and to compare these findings with the control group. METHODS: A total of 32 patients, 5 males, and 11 females in both the study (range 19-60, mean age 34.56) and control group (range 18-49, mean age 34.63) were included in the study. The file records of all patients obtained in the first evaluation were examined, and the hematological, visceral, and bone examination findings were recorded. Subsequently, oral examinations were performed for oral findings and dentomaxillofacial involvement, and radiological examinations were performed in panoramic images and cone-beam computed tomography (CBCT) images. RESULTS: There was mandible involvement in 9 (56.3%), and involvement in both jaws in 4 (25.0%) of the patients with Type I GD. According to the CBCT findings, generalized rarefaction in 10 (62.5%) patients, enlarged marrow spaces in 12 (75.0%) patients, thinning of the lamina dura in 10 (62.5%) patients, and loss in the cortical borders of the mandibular canal in 7 (43.8%) patients were among the common radiographic findings. When the control and study group were compared, in panoramic images, a significant difference was found in terms of generalized rarefaction and enlarged marrow spaces, while significant differences were found in CBCT images regarding generalized rarefaction, enlarged marrow spaces, loss in the cortical margins of the mandibular canal and widening in the periodontal ligament space. CONCLUSIONS: The roadmap for the diagnosis of Gaucher lesions in the jawbones includes a comprehensive medical history and a clinical and radiological examination. In conclusion, dentists should be familiar with the dentomaxillofacial findings of GD and be aware of possible oral and dental complications that may develop.

Proton pump inhibitors and mandibular bone quality: A preliminary study.

OBJECTIVES: Proton pump inhibitors (PPI) provide a long-lasting anti-acidic effect by inhibiting the proton pump, and they are one of the most commonly prescribed drugs worldwide. PPIs adversely affect the bone structure via deficiency of vitamins and minerals. The aim of this study was to investigate the possible PPI-induced bone changes in the mandible on panoramic radiographs with the methods of fractal analysis and panoramic morphometric indices. METHODS: Panoramic radiographs of 402 patients were used (201 PPI users, 201 control group). Fractal analysis was performed on 4 regions of interests (ROI): 1- upper part of the ramus, 2- angulus, 3- anterior of the mental foramen, 4- distal of the middle ramus. Also, the panoramic mandibular index (PMI), mandibular cortical width (MCW), and Klemetti index (KI) were performed on radiographs. RESULTS: There were significant differences in terms of ROI3, MCW, and KI between the control and study groups (p < 0.05) while there was no significant difference for ROI1, ROI2, ROI4, and PMI (p > 0.05). Males were severely affected than females. CONCLUSIONS: Osteoporotic changes were detected in the trabecular and cortical bone in the mental foramen region in PPI users with fractal analysis and morphometric indices, while there were no differences for mandibular ramus and angulus regions according to fractal analysis.

Effect of total edentulism on the internal bone structure of mandibular condyle: a preliminary study.

OBJECTIVE: The aim of this study was to assess the internal structure of the mandibular condyles in patients with total edentulism by applying fractal analysis on cone-beam computed tomography (CBCT) images and compare with dentate subjects. METHODS: A total of 136 mandibular condyles were assessed. All CBCT images were prepared with 0.25-mm slice thickness and maximum magnification. A 64 × 64 pixel region of interest (ROI) within the trabecular bone in the center of the condyle was selected. Fractal analysis was performed using White and Rudolph's box-counting method. RESULTS: Control and study groups were age and gender-matched. The mean fractal dimension (FD) value of the study group was significantly lower compared to the control group (p < 0.01). In the study group, the mean FD value of the females was significantly lower than males (p = 0.01). For the control group, there was no significant difference between the genders for FD (p = 0.11). There was no significant difference between the age subgroups of the female study group and the male control group for FD (p = 0.22, p = 0.33). The mean FD value of the younger age subgroup was significantly higher compared to the older age subgroup in the female control and male study group (p = 0.03, p = 0.01). CONCLUSION: The internal bone structure of mandibular condyles in edentulous patients was found to be affected by edentulism. Fractal analysis can be used as an effective method for assessing temporomandibular joint health.

The effect of selective serotonin reuptake inhibitors on the human mandible.

OBJECTIVES: Selective serotonin reuptake inhibitors (SSRI) are a group of drugs that selectively and strongly block the serotonin transporter. Aim of this study was to evaluate the mandibular bone structure of patients who are using SSRIs with fractal analysis and panoramic morphometric indices [mandibular cortical width (MCW), panoramic mandibular index (PMI) and Klemetti index (KI)] and to compare with control group. METHODS: Patients who declared using SSRIs for more than six months had been included in the study group. In total, 212 dental panoramic radiographs (DPR) were assessed. For fractal analysis; three regions of interest (ROIs) were determined: ROI1 and ROI2 were chosen within trabecular bone, ROI3 was selected from cortical bone. MCW, PMI, and KI were obtained from DPRs. The study group was categorized into five subgroups of various SSRIs. The fractal dimension (FD) values and panoramic morphometric indices of these subgroups were also compared. RESULTS: There was no significant difference between the groups for age and gender (p = 0.57, p = 0.5). There were significant differences in the mean FD values between the study and control groups both for the ROI1 and ROI2 (p < 0.01, p < 0.01). There was no significant difference between the groups for the mean FD value of ROI3, MCW, PMI and KI (p = 0.93, p = 0.98, p = 0.74, p = 0.06). There were no significant differences for all the values between the SSRI subgroups (p = 0.52, p = 0.7, p = 0.76, p = 0.24, p = 0.31, p = 0.08) CONCLUSIONS: Trabecular rich sites of the mandible were found to be affected by SSRI usage.

The evaluation of the mandibular bone structure changes related to lactation with fractal analysis.

OBJECTIVES: Lactation-induced bone loss of lumbar spine, hip, femur and distal radius are well documented in the literature. The aim of this article is to investigate whether lactation affects the trabecular and cortical bone structure of human mandible. METHODS: 120 dental panoramic radiographs (DPR) of the lactating women who were breastfeeding for 3-6 months (study group) and 120 DPRs of the nulliparous women (control group) were evaluated. Regions of interest (ROI) were chosen from the geometric center of ramus, the geometric center of angulus and the cortical bone. ROIs were examined with fractal analysis method. Fractal dimension (FD) values of each ROI were compared with each other. In addition, the study group was divided into four subgroups according to age, and FD values were compared within the subgroups. RESULTS: The control and study groups were age-matched. FD values of mandibular ramus and angulus were significantly lower in the study group (p < 0.001, p < 0.001). There was no significant difference for FD values of cortical bone between the groups.(p = 1.49). There was no significant difference for FD values of ROIs between the age subgroups (p = 0.05, p = 0.94, p = 0.91). CONCLUSION: This is the first study to investigate the possible effect of lactation in human jaws. Trabecular rich sites of the mandible were found affected by lactation. Dentists who encounter with lactating patients must be careful during the dental processes such as tooth extraction, implant surgery, and orthodontic treatment.

Effect of internal derangements and degenerative bone changes on the minimum thickness of the roof of the glenoid fossa in temporomandibular joint.

OBJECTIVES: The aim of this study is to investigate the effect of internal derangements and degenerative bone changes on the minimum thickness of the roof of the glenoid fossa (RGF). METHODS: MRI and cone beam CT records of temporomandibular joints (TMJ) of 68 patients were evaluated retrospectively in this study. The joints were divided into three groups according to TMJ disc status which had been diagnosed in MRI: normal disc status, anterior disc displacement with reduction, and anterior disc displacement without reduction. Cone beam CT was used to evaluate the degenerative bone changes of TMJ and to measure the minimum thickness of RGF. The joints were categorized as "with osteoarthritis (OA)" or "without OA". The findings of OA were determined as erosion, osteophyte, flattening, sclerosis, and pseudocyst. RESULTS: No significant relationship was found between gender and the thickness of RGF (p > 0.05). RGF was found significantly higher in "with OA" group compared to "without OA" group (p < 0.001). No significant difference was found between disc displacement groups for minimum thickness of RGF (p > 0.005). No significant difference was found between condyles without erosion and condyles with erosion for the minimum thickness of RGF (p = 0.272). In the present study, osteophyte, sclerosis, flattening, and pseudocyst were found to be associated with the minimum thickness of RGF. CONCLUSIONS: Osteophyte, flattening, pseudocyst, and sclerosis have an influence on RGF thickness. The minimum thickness of RGF is not significantly correlated with internal derangements. Erosion is not significantly correlated with RGF thickness. RGF thickness may be unaffected by the early stages of OA.

Evaluation of root morphology and root canal configuration of premolars in the Turkish individuals using cone beam computed tomography.

OBJECTIVE: The aim of the present study is to assess the root and root canal morphology of maxillary and mandibular premolars in a Turkish population by using cone beam computed tomography (CBCT). MATERIALS AND METHODS: In this study, CBCT images of 2134 premolars (987 maxillary, 1147 mandibular) were obtained from 404 patients. Details of gender, age, number of roots and canals, and canal configuration in each root were recorded. The canal configuration was classified and evaluated according to Vertucci's criteria. RESULTS: The majority of maxillary premolars had two separate roots; although, three roots were identified in 1% of maxillary first premolars. However, most of the mandibular premolars had a single root. The two canals (69.9%) and type I (62.6%) and type II (34.1%) configuration for upper first premolar, one canal (82.1%) and type I (77.6%) canal configuration for second premolar was the most prevalent root canal frequency. The most prevalent root canal frequency was the one canal (96.2%) and type I (94.2%) and type V (3.2%) configuration for mandibular first premolar, one canal (98.9%) and type I (98.9%) canal configuration for second premolar. There was no difference in the root canal configurations and the numbers of canals between the left and the right side of both females and males (P > 0.05). CONCLUSIONS: Recognition of morphology and anatomy of the root canal system is one of the most important factors for successful endodontic treatment. Preoperative CBCT examination allows determination of root canal configuration of premolar teeth and helps clinicians in root canal treatment.

An unusual case of ameloblastoma observed in the left anterior mandible.

AIM: To report a small intaalveolar ameloblastoma which resembled cystic lesion, and to emphasize the value of Computed tomography (CT) in radiographic examination. BACKGROUND: Ameloblastoma is a slow-growing, locally invasive odontogenic neoplasm that accounts for approximately 10% of all tumors detected in the jaws. Radiographically, those tumors are usually well-defined. Computerized tomography is highly recommended to confirm the diagnosis. CASE DESCRIPTION: A 48-year-old female attended with a chief complaint of painless swelling in the left anterior of mandible, 1 month duration. In intraoral examination, non-fluctuant, immobile, approximately 1 × 1 cm in dimension, painless, swelling which had a bone-like hardness and located in the mandibular canine region was detected. Panoramic radiography revealed a well circumscribed unilocular radiolucent lesion located in the inter-radicular area of left mandibular lateral and canine teeth. In CT examination it was realized that the lesion was multilocular. Histopathological examination of the biopsy specimen was reported as ameloblastoma. CLINICAL SIGNIFICANCE: It is extremely difficult to find such an ameloblastoma in small dimension in alvolar bone.

Oral findings of rothmund-thomson syndrome.

Rothmund-Thomson syndrome (RTS) is an extremely rare genetic condition exhibiting some dermatological, craniofacial, ophthalmological, and central nervous system abnormalities. It has an autosomal, recessive inheritance and its signs begin at childhood. Essential dermatological alteration is poikilodermatosis. A large head with an frontal bossing and broad low nasal bridge has been described in patients with RTS. Bilateral juvenile cataract is a characteristic finding of patients with RTS. Most of the patients have been markedly short and the growth retardation has been proportionate. Mental retardation is a rare condition. An 11-year-old girl who had been previously diagnosed with RTS was consulted with a chief complaint of delaying in tooth eruption. Intraoral examination revealed median rhomboid glossitis in addition to hyperkeratotic tongue. This report aimed to not only present intraoral findings of RTS, but also to demonstrate the lingual findings of a patient with RTS.

A retrospective study of the prevalence and characteristics of dens invaginatus in a sample of the Turkish population

Objective: The purpose of this study was to assess the prevalence of dens invaginatus and to classify the types of dens invaginatus in a sample of the Turkish population. Study Design: A retrospective study was performed using periapical and panoramic radiographs of 5355 patients who presented to the Department of Oral Diagnosis and Radiology at the Ondokuz Mayýs University Dentistry Faculty between January 2009 and December 2010. Maxillary and mandibular anterior teeth were evaluated for the presence and characteristics of dens invaginatus. Statistical evaluation of the presence of dens invaginatus related to gender was performed by the Pearson chi-squared test. Results: Dens invaginatus was observed in 116 of 4556 subjects, with a frequency of 2.5%. There was only one periapical lesion in teeth with type I dens invaginatus, but 8.1% of patients with type II and 87.5% of patients with type III dens invaginatus had apical periodontitis at the time of referral. There were 116 (72%) females and 32 (27%) males with dens invaginatus. Conclusion: This data represents the only study carried out in a large population in Turkey, and no dens invaginatus was found in mandibular teeth. The most commonly observed type of dens invaginatus was type I (69.8%) (AU)

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A retrospective study of the prevalence and characteristics of dens invaginatus in a sample of the Turkish population.

OBJECTIVE: The purpose of this study was to assess the prevalence of dens invaginatus and to classify the types of dens invaginatus in a sample of the Turkish population. STUDY DESIGN: A retrospective study was performed using periapical and panoramic radiographs of 5355 patients who presented to the Department of Oral Diagnosis and Radiology at the Ondokuz Mayis University Dentistry Faculty between January 2009 and December 2010. Maxillary and mandibular anterior teeth were evaluated for the presence and characteristics of dens invaginatus. Statistical evaluation of the presence of dens invaginatus related to gender was performed by the Pearson chi-squared test. RESULTS: Dens invaginatus was observed in 116 of 4556 subjects, with a frequency of 2.5%. There was only one periapical lesion in teeth with type I dens invaginatus, but 8.1% of patients with type II and 87.5% of patients with type III dens invaginatus had apical periodontitis at the time of referral. There were 116 (72%) females and 32 (27%) males with dens invaginatus. CONCLUSION: This data represents the only study carried out in a large population in Turkey, and no dens invaginatus was found in mandibular teeth. The most commonly observed type of dens invaginatus was type I (69.8%).

Radiographic evaluation of alveolar ridge heights of dentate and edentulous patients.

OBJECTIVE: To evaluate the reduction of residual alveolar ridge height on panoramic radiographs and the differences between denture wearers and non-denture wearers. MATERIALS AND METHODS: The study consisted of 147 individuals (74 men and 73 women) [50 were denture wearers and 50 non-denture wearers (examination groups) and 47 of them were dentate (control group)]. Individuals having diseases impacting on bone were excluded. Vertical measurements were made at 15 sites (central incisors, first premolars and molars at the left and right of both jaws and the distance between the zygoma/orbit). MANOVA (multi-variate analysis of variation) was used for the statistical analysis of the results. RESULTS: There were significant differences between the alveolar ridge heights of dentate and edentulous groups (p < 0.001). Between the denture wearer and the non-denture wearer groups, there was significant difference in the lower jaw (p < 0.001), but no significant difference in the upper jaw (p = 0.635). There were also differences between men and women (p < 0.005) and upper and lower jaws at every measurement sites (p < 0.01). CONCLUSION: Reduction in residual alveolar ridge height was in close relation with gender, denture usage and edentulousness.