Lingual Aspect Research Articles

Pyogenic Granuloma

Pyogenic granuloma (PG) is hyperplastic inflammatory lesion or growth occurring due to constant irritation, traumatic injury, or hormonal factors. PG can occur on the skin and oral cavity. In the oral cavity, it most often occurs in the gingiva. Other oral sites involved are buccal mucosa, lip, tongue, and palate. Histopathological examination is crucial for its accurate diagnosis as it can be misdiagnosed due to its clinical resemblance with peripheral ossifying fibroma, peripheral giant cell granuloma, hemangioma, and fibroma. Here, we present a case of an 18-year-old male having a lesion in the mandible anterior region in the lingual aspect of the gingiva.

The Relationship between Orthodontics and Periodontics– A review

The periodontal aspects of orthodontic treatment are reviewed in this article highlighting the cases of maxillary expansion, molar extrusion, and class III malocclusions. Gingival recession is dependent on two main factors namely, gingival biotype and the bone morphology. Teeth when placed in the center of the alveolar ridge and having adequate bone support circumferentially and alveolar bone on the labial and lingual aspects of the roots are considered to the best for supporting the teeth. The arch width can be increased with expansion appliances such as RPE which may lead to undesired effects on the periodontium. In this article, we review how mini-screws can be used for expansion in posterior crossbite and protraction of maxillary arch in class III malocclusions to prevent periodontal issues.

Keratinized mucosa changes around one-stage implants: A prospective case series.

The need of an adequate band of keratinized tissue (KT) to maintain periodontal health around teeth as well as around implants has been a debated topic over many years but still no conclusions have been drawn. This prospective case series evaluates the changes undergone by the keratinized mucosa (KM) and the soft tissue volume around non-submerged implants before the prosthetic rehabilitation. A total of 40 patients were included. The primary outcome was to analyze the width of the KM at both buccal and lingual aspects compared to the pre-existing KT in the edentulous ridge only in mandibular (pre)molar area. The mucogingival line was marked with a surgical pen and an intra-oral scanner was used to take the impression of the implant area the day of the surgery (T0, baseline) and before the crown placement (T1, 3months). Buccal soft tissue volume was measured at 1, 3, and 5 mm apical to the healing abutment position and a comparison between T0 and T1 was performed. Student t-test was used according to the distribution of the data (Shapiro-Wilk). The mean KT width at baseline was 4.54 ± 1.31 mm at buccal side and 5.04 ± 1.88 mm at lingual side. After 3months, the mean KM values were 3.15 ± 1.03 mm and 3.72 ± 1.56 mm at the buccal and lingual aspects, respectively. The differences, 30.6% of KM reduction buccally and 26.1% of reduction lingually, were statistically significant for both sides. Within the limitations of this investigation, it was observed that the KM width from the baseline to the 3months follow up presented a significant dimensional change in both the buccal and lingual aspects, whereas buccal soft tissue volume showed an increase between baseline and follow up.

Effect of intracanal diode laser irradiation on fracture resistance of roots restored with CAD/CAM posts

Aim: To evaluate the fracture resistance of roots restored with CAD/CAM-fabricated posts, receiving or not intracanal laser treatment, compared with glass fiber posts under mechanical cycling. Methods: Twenty-seven endodontically treated, single-rooted teeth were divided into 3 groups: group 1 (control), prefabricated glass fiber posts relined with resin composite; group 2, CAD/CAM-fabricated intraradicular posts using Resin Nano Ceramic (RNC) blocks; and group 3, CAD/CAM-fabricated intraradicular posts using RNC blocks in canals irradiated with a 940-nm diode laser (100 mJ, 300-um optic fiber, coronal-apical and apical-coronal helical movements, speed of 2 mm/second, 4 times each canal). After cementation of the coping, cyclic loading was applied at an angle of 135° to the long axis of the root, with a pulse load of 130 N, frequency of 2.2 Hz, and 150,000 pulses on the crown at a point located 2 mm below the incisal edge on the lingual aspect of the specimen. Every 50,000 cycles, the specimens were evaluated for root fracture occurring below or above the simulated bone crest. Results were analyzed by one-way ANOVA followed by Tukey’s test (p<0.05). Results: Group 1 was the least resistant, while groups 2 and 3 were the most resistant. Group 1 differed significantly from groups 2 and 3 (p<0.01), but there was no difference between groups 2 and 3 (p<0.01). Conclusion: Treatment of the intracanal surface with diode laser had no influence on fracture resistance of roots restored with CAD/CAM-fabricated posts, but a longer cycling time is required to evaluate the real benefits of diode laser irradiation.

Variability associated with mandibular ramus area thickness and depth in subjects with different growth patterns, gender, and growth status

The purpose of this study was to quantitatively evaluate the ramus bone parameters (ramus thickness and ramus depth) for miniscrew placement. An additional aim was to compare and contrast the ramus bone parameters in growing and nongrowing male and female subjects with hyperdivergent, normodivergent, hypodivergent facial types.Cone-beam computed tomography scans of 690 subjects were evaluated. They were classified in terms of growth status, gender, and facial type. Ramus thickness was measured as the distance from the outer (buccal) to the inner (lingual) aspects of the mandibular ramus. Ramus depth was measured as the distance from the anterior border of the ramus to the inferior alveolar nerve canal. The measurements for ramus thickness and ramus depth were performed at 3 different levels bilaterally: (1) occlusal plane (OP), (2) 5 mm above the occlusal plane (5OP), and (3) 10 mm above the occlusal plane (10OP).Males showed a significantly higher ramus thickness than females (P <0.05). Ramus thickness decreased significantly (P <0.05) as we moved superior from the level of OP to 5OP and 10OP in all 3 facial types in both females (growing and nongrowing) and males (growing and nongrowing). Growing females and growing males had significantly higher ramus thickness than nongrowing females and nongrowing males, respectively. Ramus depth increased as we moved higher from the OP to 10OP. Hyperdivergent facial type showed a significantly reduced ramus depth compared with hypodivergent and normodivergent facial type in growing and nongrowing males and females at all 3 locations, namely OP, 5OP, and 10OP (P <0.05).Because of adequate ramus depth and ramus thickness, 5OP was considered the optimal insertion site for the placement of miniscrews. Patients with a hyperdivergent facial type showed significantly reduced ramus depth than hypodivergent and normodivergent facial types. Ramus thickness in males was significantly higher than in females in all facial types.

WAROK REPRESENTATION IN THE ART OF REOG PONOROGO (ANTROPOLINGUISTIC STUDY)

The study purpose is to identify lingual aspect of Tembang Pangkur (TP) and describe its relationship with culture to represent Warok character. Lingual aspects of TP are identified through lexical cohesion, grammatical cohesion, and other language peculiarities, while relationship of TP with culture is described by transcendental theory. This study method is descriptive qualitative with stages, includes data collection, transcripts, analysis, interpretation, and make conclusions. The object as well as data in this study is TP contained in Serat Wedhatama, 12th stanza by K.G.P.A.A. Mangkunegara IV. The TP is often used by Reog cultivators to represent Warok character. The results of the study, including (1) lingual aspect of TP shows a complete relationship of form and meaning until a meaningful causal relationship is obtained, namely if someone wants to become a wong sepuh (Warok) then must receive divine revelation; (2) relationship between TP and culture shows the existence of Sufism teachings whose implementation is formulated with catur sembah. A person who has performed catur sembah can be said to be a wong sepuh. Likewise in the art of Reog Ponorogo, Warok is represented as a wong sepuh as described in TP.

1678 A Rare Example of a Simple Bone Cyst of The Ascending Ramus in A Paediatric Patient

Abstract A simple bone cyst is described as an intra-osseous pseudocyst, devoid of an epithelial lining and either empty of filled with serous or sanguineous fluid. This case presents a rare example of a simple bone cyst of the ascending ramus of the mandible in a paediatric patient. Studies have shown that less than 5% of simple bone cysts of the jaw bones are located within the mandibular ramus, with the most common site being the premolar-molar region (75%). The 14-year-old female was referred by her orthodontist to the local Oral and Maxillofacial department, for an incidental finding on her pre-orthodontic OPT of a radiolucency in the left ascending ramus. Her medical history was clear, she was asymptomatic and had no sensory deficit. A CT scan demonstrated a 22mm multilocular radiolucency centred on the left ascending ramus, extending superiorly up to the base of the coronoid process and condylar neck. Inferiorly, the radiolucency abutted but did not involve the unerupted third molar. The scan highlighted thinning of the buccal and lingual cortices putting the patient at risk of pathological fracture. The inferior alveolar nerve canal passed through the lingual aspect of the radiolucency. The patient underwent exploration of the left mandible which revealed an empty bony cavity, with no cystic lining or contents. The definitive diagnosis of a simple bone cyst was established. She experienced satisfactory healing by her review appointment 4 weeks post-surgery. Combined radiographic and clinical assessment is important in the diagnosis of simple bone cysts.

A randomized controlled trial of ball and socket vs O-ring attachments for single implant-retained mandibular overdentures. A study of crestal bone loss and patient satisfaction

Purpose: This short term randomized controlled trial aimed to evaluate crestal bone loss and patient satisfaction of ball and socket and O-ring attachments used to retain single implant-retained mandibular overdenture after one year. Materials and methods: Twelve completely edentulous patients received single implant in the midline of the mandible. Three months later, the patients were randomly assigned into two groups; Group 1 (control group); six patients their mandibular dentures were connected to the implant using ball and socket attachment. Group 2 (test group); included six patients their mandibular dentures were connected to the implant using O/ring attachment. The peri-implant crestal bone loss was evaluated at mesial, distal, buccal and lingual aspects of each implant using cone beam computerized tomography made at baseline, 6 and 12 months later. Patient satisfaction was evaluated using questionnaire of visual Analogue Scales (VAS) six months after loading. Results: The implant survival rate was 100% in both groups. Ball and socket attachment recorded significant higher crestal bone loss than O-ring attachment after 6 months (p=.031) and 12 months (p=.021). Ball and socket attachment recorded significant higher patient satisfaction than O/ring attachment. Conclusion: O/ring attachment is recommended than ball and socket attachment for single implant mandibular overdentures in term of peri-implant bone preservation. However, ball and socket attachment was associated with significant higher patient satisfaction than O/ring attachment.

Peripheral Giant Osteoma of Mandible: Report of a Case and Review of the Literature

Osteoma of the jaw bones is a rare entity with very few cases reported in the literature. Osteomas are benign, slow growing osteogenic tumors of the bone commonly encountered in the craniofacial skeleton and characterised by the proliferation of compact or cancellous bone. They can be central, peripheral or extra-skeletal in their location .The solitary periosteal osteomas of the jaw bones are quite rare. The mandible is more commonly affected than the maxilla, with the sites of predilection being the lingual aspect of the body, the angle and the inferior border. The diagnosis is based on the clinic, the radiological examinations. The CT scan is the best imaging modality as it provides exact details about the site, dimensions and extension of the lesion. Additional three-dimensional CT imaging helps planning the surgery. Confirmation of the diagnosis is pathological. Surgical management should be indicated both for cosmetic complaints and for diagnostic confirmation, especially in bulky lesions. We report a case of a Peripheral Giant Osteoma of Mandible in a 60-year-old man.

A new hadrosauriform dinosaur from the Wessex Formation, Wealden Group (Early Cretaceous), of the Isle of Wight, southern England

A new genus and species of non-hadrosaurid hadrosauriform dinosaur, Brighstoneus simmondsi gen. et sp. nov., is described from the Lower Cretaceous Wessex Formation of the Isle of Wight. The new taxon has two autapomorphies, a nasal having a modest nasal bulla with convex sides, and primary and accessory ridges on the lingual aspect of the maxillary crown. The dentary has at least 28 alveolar positions, which is the highest number recorded in an ornithopod with non-parallel sided alveoli, creating a character combination that is unique within Iguanodontia. The hadrosauriform fauna of the Barremian–Aptian Wealden Group on both the Isle of Wight and mainland England has been represented for almost a century by just two taxa, the robust Iguanodon bernissartensis and the more gracile Mantellisaurus atherfieldensis, with referred material often being fragmentary or based on unassociated elements. This discovery increases the known hadrosauriform diversity in England and, together with recent discoveries in Spain, suggests that their diversity in the upper Wealden of Europe was considerably wider than initially realized. This find also has important implications for the validity of the Mantellisaurus atherfieldensis hypodigm, and a reassessment of existing material is suggested. http://zoobank.org/urn:lsid:zoobank.org:pub:31F0D48F-C1DA-406E-A811-1F5937ED19F4

Evaluation of the marginal and internal gaps of partially crystallized versus fully crystallized zirconia-reinforced lithium silicate CAD-CAM crowns: An in vitro comparison of the silicone replica technique, direct view, and 3-dimensional superimposition analysis

Statement of problemThe crystallization process of lithium disilicate crowns has been reported to cause dimensional change, but whether the fit of chairside computer-aided design and computer-aided manufactured (CAD-CAM) zirconia-reinforced lithium silicate crowns is affected is unclear. PurposeThe purpose of this in vitro study was to evaluate with a 3-dimensional superimposition analysis technique the marginal and internal adaptation of fully crystallized versus partially crystallized zirconia-reinforced lithium silicate ceramic CAD-CAM fabricated crowns. Additionally, the silicone replica technique and direct viewing of marginal gap values were compared with the 3-dimensional superimposition analysis technique. Material and methodsThe marginal and internal adaptation of a fully crystallized zirconia-reinforced lithium silicate (CELTRA DUO) were compared with those of a partially crystallized zirconia-reinforced lithium silicate (VITA SUPRINITY) after crystallization. Sixteen crowns (n=8) were fabricated with a chairside CAD-CAM system. The crowns and die and crown assembly were scanned with an optical scanner for the 3-dimensional superimposition analysis. Four hundred sixty-eight measurements were made for each crown, 78 in each 2-dimensional section. Marginal discrepancy was measured by using the direct viewing technique. The internal adaptation of the shoulder area, axial space, and occlusal space was measured by using the silicone replica technique. Both gap values were compared with the 3-dimensional superimposition analysis results by using the independent t test. The 2-way ANOVA was used to detect the effect of each variable (group and site) (α=.05). ResultsThe VITA SUPRINITY crowns showed statistically higher marginal discrepancy values than the CELTRA DUO crowns in both 3-dimensional superimposition analysis and the direct viewing method, and the lingual aspect recorded the highest marginal discrepancy mean value when compared with other aspects. The 3-dimensional superimposition analysis and the direct viewing method were statistically similar (P=.076). The VITA SUPRINTY crowns showed higher internal gap mean values than the CELTRA DUO crowns in both 3-dimensional superimposition analysis and silicone replica techniques. The occlusal space recorded the highest mean value in both groups. Assessment by 3-dimensional superimposition analysis and silicone replica techniques showed statistical difference in internal gap values (P=.04). ConclusionsCELTRA DUO showed better precision fit values than VITA SUPRINITY. Three-dimensional superimposition analysis is a reliable method of evaluating marginal and internal adaptation.

Evaluation of the Bone Thickness of Mandibular Molars using Cone Beam Computed Tomography

Objective: To investigate buccal and lingual bone thicknesses and fenestration rate of mandibular first and second molars using cone-beam computed tomography (CBCT). Methods: A total of CBCT images of 41 patients were selected and overall 120 mandibular molars were investigated. The buccal and lingual alveolar bone widths were measured at apex of the roots. The prevalence of fenestration in mandibular molars was recorded. Statistical analyses were performed. Results: The buccal bone widths of mesial root of second molars were significantly lower than the lingual (p&lt;0.05). The lingual bone widths of mesial and distal root of second molars were lower than the buccal (p&lt;0.05). The lowest thickness of buccal and lingual bone was observed in mesial root of first molar and distal root of second molar. The prevalence of fenestration in mandibular first and second molars was 5% and 10%. Conclusion: The buccal bone widths were lower at the first molar than the second molar. All fenestrations in first molar were in buccal aspect, in second molar were in lingual aspect. Topographical proximity of the buccal side of first molar and the lingual side of second molar to bone plate create a risky region for endodontic treatment or spread of infection.

Withdrawal: "Torus lesions of the jaw: Diagnosis and clinical implications" Gary G. Ghahremani, David R. Naimi, Zohreh K. Ghahremani.

This article is being re-evaluated as of 05 July 2021 for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi:10.1111/ijcp.13697.

METASTATIC MEDULLOBLASTOMA TO THE MANDIBLE: A CASE REPORT

<h3>Introduction</h3> Medulloblastoma is the most common tumor of the brain of neuroendocrine origin in children and typically demonstrates an aggressive, relentless clinical behavior and high recurrence rate. Extraneuraxial metastasis of medulloblastoma to the jaw is extremely rare, with fewer than 10 cases reported in the literature. <h3>Case Report</h3> A 10-year-old male patient presented with a swelling in the right side of the face for 15 days. The patient had a past history of medulloblastoma diagnosed a few years earlier. Clinical examination revealed a diffuse painless mass in the right mandible. Multiplanar reconstruction demonstrated a 1.5 × 1.5 cm well-defined round lesion with extensive necrosis involving mostly the ramus of right mandible with resultant bone erosion on the lingual aspect. The lesion involved the regional structures including maxillary sinus, pterygoid process, and carotid sheath. Microscopic examination of the biopsy specimen exhibited sheets of poorly differentiated malignant small round blue cells with extensive necrosis. The tumor cells revealed molding of nuclei with speckled chromatin and inconspicuous cytoplasm. Evidence of vascular and perineural invasion was noted. Immunohistochemical studies demonstrated weak granular positivity for synaptophysin, but staining for AE1/3, desmin, CD99, and LCA was negative in the lesion tissue. A diagnosis of round blue cell malignancy of neuroendocrine origin compatible with medulloblastoma metastatic to the jaw was rendered. Our case represents only the 10th such as case in the English-language literature. Owing to the rarity of this entity, a more accurate understanding of the prognosis and treatment of metastatic medulloblastoma is not well known.

INTRAOSSEOUS EPITHELIOID HAEMANGIOENDOTHELIOMA OF THE MANDIBLE

Case A fit and well 25-year-old man presented with worsening pain and bony swelling on the lingual aspect of the right premolar region. Radiology showed a multiloculated radiolucent lesion of the anterior mandible with bone expansion and displacement of roots. Initial biopsy revealed fragments of nested epithelioid tumor within the marrow space with extravasated red blood cells and hemosiderin suggestive of vascular origin. Further biopsy showed histologic features of epithelioid haemangioendothelioma (eHAE). Samples were sent to the National Orthopaedic Hospital for molecular testing but this was inconclusive, likely owing to formic acid decalcification. MDT decision for surgical resection was carried out with primary reconstruction. Histology from the resection revealed complete excision of eHAE with focal erosion through the buccal cortex. The patient has recovered well, and to date there is no evidence of recurrence. Discussion eHAE is a very rare vascular tumor of low-grade malignancy, which presents within the lung, liver, or bone including of the head and neck region with 4 cases reported within the mandible. Despite characteristic morphology, diagnosis can be challenging because of small sample size and the rarity of diagnosis. eHAEs are characterized by a WWTR1-CAMTA1 fusion with a minority also showing a YAP1-TFE3 fusion, however decalcification in formic acid can prevent adequate molecular analysis. Conclusions eHAE is a rare tumor with characteristic histologic features and potential for recurrence and metastasis. Molecular testing can assist diagnosis, and development of local tissue pathways for intraosseous tumors that facilitate molecular testing is essential for prompt diagnosis.

Impact of piezocision-assisted orthodontics on root resorption and alveolar bone: a prospective observational study.

To assess the impact of orthodontic treatment combined with piezocision (OT-PC) on root structure and alveolar bone. Twelve adults were treated with OT-PC. Pre- and post-treatment CBCT examinations evaluated apical root resorption (ARR) and alveolar bone height and thickness changes. Pre- and post-treatment differences were compared using one-sample t test and Wilcoxon signed-rank test. ARRs were generalized and significantly more severe in both anterior sextants compared with posterior sextants. Bone thickness decreased significantly in the maxilla at mid-root and apex areas. The majority of mandibular alveolar bone dehiscences occurred on the buccal aspect at the mid-root level, especially where thickness was less than 0.3mm. Overall bone height decreased twice as much on the buccal aspect (1.43mm, P < 0.001) compared with the lingual aspect (0.67mm, P = 0.001), most significantly in the lower incisors, where the average median loss was 2.10mm (P = 0.003). OT-PC causes minor negative effects on both alveolar bone and root resorption. Orthodontic treatment combined with piezocision causes minor negative effects on periodontal support. Nevertheless, mild bone height loss on the buccal aspect of the mandibular teeth and root resorption in both anterior sextants have been detected with this new treatment.

Tilted versus Short Implants Supporting Mandibular Fixed Detachable Prosthesis (In vitro study)

Purpose: This study aimed to evaluate strain induced in implants supporting fixed detachable prosthesis with different implant protocols using strain gauge analysis. Material and methods: This stress analysis study used two 3D models simulating a completely edentulous lower arch to support and retain fixed detachable prostheses. In the first model four implant beds were considered; two anterior implants oriented axially and two posterior implants placed at the premolar region tilted 30 degrees. In the second model implant beds were designed with two anterior implants oriented axially and two short posterior implants 8 mm length placed in the first molar region oriented axially. Standardized static load was applied unilaterally by using a loading device (universal-testing machine). Strain gauge was used to measure strains induced in each implant. Results: Regarding the loaded side: Strain induced in the anterior implant and in the lingual and distal aspect of the posterior implant in the first model has shown higher strains compared to the second model. This difference was statistically insignificant in the anterior implant and in the lingual aspect of the posterior implant, while strains induced in the distal aspect of the posterior implant was statistically significant higher in the first model compared to the second model. Conclusion: With the limitation of this in vitro study, it can be concluded that short implants induce less stresses distally than tilted implants.

Hemangiopericytoma of the Gingiva – A Case Report

Hemangiopericytoma (HPC) is a very rare tumor with uncertain malignant potential. It is a soft tissuetumor which originates from the pericytes in the walls of the blood capillaries. Both benign and malignantvarieties are present with the tendency to metastasize. It was first described by Stout and Murray in 1942.The incidence of occurrence in oral cavity is very rare. We report a case of 57 year old male, who presentedwith an exophytic overgrowth from the lingual aspect of the maxillary left gingiva which extended into thepalatal area. The tumor was completely removed with wide surgical excision. The histopathological studyof the tumor suggested the HPC.

Long-term periodontal changes associated with oral appliance treatment of obstructive sleep apnea.

To characterize the mandibular anterior teeth crown height as a marker of periodontal changes and bone loss as a side effect of an oral appliance worn for a minimum of 4.5 years. This retrospective study conducted in patients with healthy baseline periodontium recruited participants among consecutive sleep apnea patients treated with an oral appliance between 2004 to 2014. Eligible participants were recalled for a follow-up visit at which a periodontal examination was performed and a lateral cephalogram and dental impressions were obtained. Clinical crown height for mandibular anterior teeth and cephalometric variables were measured and compared before and after treatment. A full periodontal evaluation was performed at the follow-up visit. Twenty-one patients enrolled with a mean treatment length of 7.9 ± 3.3 years. For the mandibular anterior teeth, clinical crown height did not change over the evaluated period. At follow-up, all the periodontal assessed variables were within normal limits, with the mean probing depth of 1.4 ± 0.5 mm, recession 0.6 ± 1.1 mm, and clinical attachment loss 0.8 ± 1.0 mm. Compared with baseline, there was a significant proclination of mandibular incisors (mean increase of 5.1 degrees) with the continued use of an oral appliance. Gingival levels were maintained with clinically insignificant changes during the observation period. Inclination of the mandibular incisors increases significantly with the use of an oral appliance in patients with obstructive sleep apnea. Positional changes in these teeth were not associated with any measured evidence of increase in clinical crown height or gingival recession. Heda P, Alalola B, Almeida FR, Kim H, Peres BU, Pliska BT. Long-term periodontal changes associated with oral appliance treatment of obstructive sleep apnea. J Clin Sleep Med. 2021;17(10):2067-2074.

Localization of the First Mandibular Molar Roots in Relationship to the Mandibular Canal in Small Breed Dogs-A Tomography Imaging Study.

The intimate relationship between the mandibular canal (MC) and the first mandibular molar tooth presents challenges when performing dentoalveolar surgical procedures due to the probability of causing iatrogenic injury to the inferior alveolar neurovascular bundle. Superimposition between the MC and the first molar (M1) tooth roots is often observed on intraoral dental radiographs in small breed dogs. However, due to the radiograph's bidimensional nature, it is impossible to determine the buccal or lingual localization of the first molar roots with respect to the MC. Thus, this study's objective was to determine the localization of the first molar tooth's roots in relation to the position of the MC and their overlapping percentage with the canal in small-bodyweight dogs (<15 kg) using tomographic diagnostic images. For this, cone-beam computed tomography and high-definition computed tomography exams from 103 small breed dogs (under 15 kg) were retrospectively assessed to determine the lingual or buccal localization of the first molar tooth's roots with respect to the MC and the degree of overlap of the roots with the canal. In conclusion, most of the roots of M1 of dogs under 15 kg were located at the MC's lingual aspect (82.7%) with an overall superimposition median with the MC of 100 and 90% for the mesial and distal roots, respectively. Straddle tooth roots were not a common anatomical presentation in the dogs of this study.