Pre-eruptive intramural resorption in unerupted teeth: a cone-beam computed tomography evaluation of prevalence and related factors.

OBJECTIVE: Pre-eruptive intramural resorption (PEIR) is defined as an abnormal, well-circumscribed radiolucency within the coronal dentin of the tooth, which is often overlooked in plain radiographs. This study aimed to investigate the prevalence of PEIR and its related factors using cone-beam computed tomography (CBCT). METHODS: CBCT images of 590 unerupted teeth were evaluated for the presence of PEIR, location of PEIR, number of lesions in the affected tooth, PEIR score, tooth angulation, tooth position, and pericoronal space. Binary logistic tests were used to analyze the association between the characteristics of PEIR and the patient's demographic data and related factors. RESULTS: The tooth prevalence of PEIR was 13.6% among unerupted teeth. However, it was noteworthy that 19.2% of the unerupted teeth with PEIR were planned to be kept. PEIR was significantly associated with transverse (p = 0.020), inverted-angulated (p = 0.035), and centrally-positioned teeth (p = 0.043). The severity of PEIR was more pronounced in teeth with distal (p = 0.019), lingual (p = 0.023), or inverted-angulated (p = 0.040) positions, and in the absence of pericoronal space (p = 0.036). CONCLUSION: PEIR should be suspected in transverse, inverted-angulated, centrally positioned unerupted teeth, particularly in molars, with no pericoronal space. Further monitoring through CBCT is recommended in such cases. CLINICAL RELEVANCE: The management of unerupted teeth does not always involve surgical removal. Instead, they could be utilized for artificial eruption or tooth transplantation. The present study emphasizes the significance of early detection of PEIR. Clinical recommendations for screening PEIR in unerupted teeth are also proposed, which can be applied to routine plain radiographs.

Assessment of Nasal Septum Change after Le Fort I Osteotomy Using Cone Beam Computed Tomography.

Objective: Le Fort I osteotomy (LF-IO) is widely used for the correction of dentofacial deformities, which may cause changes in the postoperative nasal septum (NS). The objective of this study was to evaluate the effects of LF-IO on the NS deviation and to determine whether the NS was affected by differences in the direction of maxilla movement. Materials and Methods: A retrospective study including 57 patients who underwent LF-IO and received cone beam computed tomography (CBCT) preoperatively and 6-12 months postoperative evaluation was performed. The NS angle of each patient was measured both pre- and postoperatively in the two coronal sections (nasion and ostium levels). The patients were divided into five paired groups and calculated. Group 1 to 4 were divided depending on the differences in the direction of maxilla movement (Group 1. Impaction ≥ 5 mm vs. Impaction < 5 mm; Group 2. Anterior movement vs. Non-anterior movement; Group 3. Impaction symmetry vs. Impaction asymmetry; and Group 4. Impaction vs. Inferior repositioning). Group 5 was divided as One-piece osteotomy vs. Multi-segmental osteotomy. Results: The mean NS angles at both nasion and ostium levels of all patients were significant increased after LF-IO. However, there were no statistical significant differences of the five paired groups. Conclusions: LF-IO osteotomy influenced increasing of the NS deviation at both the nasion and ostium levels. However, differences in the direction of the maxilla movement and maxilla segmentation showed no statistically significant changes.

Prevalence and morphometric analysis of the alveolar antral artery in a group of Thai population by cone beam computed tomography.

OBJECTIVE: To investigate the prevalence, diameter, and position of the alveolar antral artery (AAA) canals and measure the distances from the canal to the maxillary sinus floor and to the edentulous alveolar crest in each posterior maxillary tooth locations by cone beam computed tomography (CBCT). METHODS: CBCT images of the posterior maxillary region from 280 patients were investigated. The prevalence and diameter of the AAA canal were evaluated. The perpendicular distances from the canal to the maxillary sinus floor and to the edentulous alveolar crest of each tooth locations were measured. The mediolateral positions and routes of the canals were observed with novel classification. Statistical analyses were carried out to determine any significant differences in mean distances between the tooth locations along with mean distances of tooth location by age, gender, and dentate status. RESULTS: The AAA canal was found in 94.6% with a mean diameter ± SD of 1.05 ± 0.34 mm. The mean ± SD perpendicular distance from AAA canal to the edentulous alveolar crest at the first (16.02 ± 3.94 mm) and the second molars (16.74 ± 3.51 mm) were significantly shorter than the second premolar region. The intrasinus mediolateral position of the canal (72.5%) was the most common in concordance with the all-in type mediolateral route (50.9%). CONCLUSION: The intrasinus mediolateral position of the AAA canal is a common structure in the lateral wall of maxillary sinus, which could be detected with CBCT images. The all-in type is the most prevalent mediolateral route among a novel 7-type classification system of AAA routes. Owing to the short distance between the AAA canal and the alveolar crest in the first and second molar locations, CBCT images should be taken to investigate the AAA position and route before sinus lift procedure to prevent the risk of hemorrhage.

Quantitative and qualitative assessments of intraosseous neurovascular canals in dentate and posteriorly edentulous individuals in lateral maxillary sinus wall.

OBJECTIVE: Knowledge and evaluation of the blood supply within the maxillary sinus before sinus augmentation are vital to avoid surgical complications. The lateral maxilla is supplied by branches of the posterior superior alveolar artery and infraorbital artery forming intraosseous anastomoses (IA) within the bony lateral antral wall. This study was undertaken to (i) measure mean diameter of IA and its distance from the alveolar ridge within dentate and posteriorly edentulous subjects and, (ii) qualitatively display the relationship of IA throughout its course within the lateral maxillary sinus in cone beam computed tomography (CBCT). METHOD: Maxillary CBCT images of two-hundred-and-fifty-seven consecutive patients (163 men, 94 women, mean age 42 years) were analyzed. Samples were later divided into dentate (n = 142) and posteriorly edentulous (n = 115) jaws. Using both alveolar ridge and tooth location as reference points, the distance and diameter of IA were assessed. RESULT: The IA was seen in 63.7% of all sinuses with 68.2% in dentate and 62.4% in edentulous. Mean distance and diameter of IA across the posterior tooth locations were 17.9 ± 3.0 mm and 1.4 ± 0.5 mm (dentate) and 15.1 ± 3.0 mm and 1.0 ± 0.5 mm (posteriorly edentulous), respectively. In each sample, there were no significant differences in distance-alveolar ridge and no significant correlations in diameter-tooth location. A statistically significant Pearson coefficient correlation between diameter and distance in dentate state was observed (r = -0.6). CONCLUSION: This study reveals that dentate maxillary jaws present larger diameters as compared to posteriorly edentulous jaws, although the IA course remains the same. As these canal structures contain neurovascular bundles with diameters that may be large enough to cause clinically substantial complications, a thorough pre-surgical planning is therefore highly advisable.

Diffusion tensor imaging of the inferior alveolar nerve using 3T MRI: a study for quantitative evaluation and fibre tracking.

OBJECTIVES: Diffusion tensor imaging (DTI) can provide structural information and objective values for nerves. The aims of this study were to perform quantitative evaluation and fibre tracking of the normal inferior alveolar nerve (IAN) using DTI on 3.0-T MRI. METHODS: DTI was applied to 92 IANs of 46 healthy volunteers. Circular regions of interest (ROIs) were placed on three different positions at the mandibular foramen, second molar and mental foramen of each nerve on apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps, and the ADC and FA of each ROI were measured. Differences in the values arising from the nerve positions were evaluated. Furthermore, fibre tracking of the IANs was performed by tractography, and the quality of visualization was evaluated. RESULTS: There were no significant differences in the ADC and FA between the right and left sides regardless of the anteroposterior positions. Regarding differences arising from the anteroposterior measurement positions, the ADC and FA showed no significant differences (p > 0.017), except for the ADCs between the positions at the mandibular foramen and mental foramen in the left side (p = 0.0068). Overall, 70 (76%) of the 92 IANs could be visualized fully or partially by tractography. CONCLUSIONS: The ADC and FA of the IAN were successfully obtained from healthy volunteers using DTI and were confirmed to be symmetrical regardless of the measurement positions. DTI is a feasible technique for the quantitative evaluation and visualization of the IAN.

Longitudinal MRI follow-up of rheumatoid arthritis in the temporomandibular joint: importance of synovial proliferation as an early-stage sign.

This article describes longitudinal magnetic resonance imaging (MRI) observations in a patient with rheumatoid arthritis of the temporomandibular joint. The characteristic findings included marked synovial proliferation, which was observed before the onset of severe bone destruction. MRI is considered to provide valuable information for the early detection of rheumatoid arthritis of the temporomandibular joint.