Surgical peri-implantitis treatment with and without guided bone regeneration. A randomized controlled trial.

OBJECTIVE: To evaluate the efficacy of reconstructive peri-implantitis treatment. MATERIALS AND METHODS: Forty participants, with peri-implantitis and a contained intraosseous defect, were randomized to access flap (control) or access flap with xenograft and collagen membrane (test). All received systemic antimicrobials. Blinded examiners recorded probing depths (PD), bleeding and suppuration on probing (BOP & SOP), soft tissue levels, and marginal bone levels (MBL) at baseline and 12 months. Patient reported outcomes were recorded. The primary outcome was PD change. RESULTS: All 40 participants (40 implants) completed the 12-month study. The mean (standard deviation) PD reduction (deepest site) was 4.2 (1.8) mm in the control and 3.7 (1.9) mm in the test group. MBL gain (deepest site) was 1.7 (1.6) mm in the control and 2.4 (1.4) mm in the test group. Absence of BOP & SOP was observed at 60% of both control and test implants. Buccal recession was 0.9 (1.6) mm in the control and 0.4 (1.1) mm in the test group. A successful outcome (absence of PD ≥ 5 mm with BOP, absence of SOP and absence of progressive bone loss) was achieved for 90% of the control and 85% of test group implants. No statistically significant differences in clinical or radiographic parameters were found between treatment groups. 30% of participants experienced mild gastro-intestinal disturbances. Reporting followed CONSORT guidelines. CONCLUSION: Similar clinical and radiographic improvements at 12 months were observed with high levels of patient satisfaction for both the access flap and xenograft covered by collagen membrane groups. Registered clinical trials.gov. ID:NCT03163602 (23/05/2017).

Inferior alveolar nerve injury: Correlation between indicators of risk on panoramic radiographs and the incidence of tooth and mandibular canal contact on cone-beam computed tomography scans in a Western Australian population.

AIM: The aim of the present study was to assess risks prior to third molar removal. A 2-D panoramic radiograph or a 3-D cone-beam computed tomography (CBCT) scan can be used to visualize the proximity of the third molar to the mandibular canal. We aimed to correlate panoramic indicators of risk with the incidence of contact between these two structures on CBCT scans. METHODS: Patients were selected from a Western Australian population if they had a panoramic radiograph that illustrated signs of risk of inferior alveolar nerve injury and had a CBCT scan on file. Statistically-significant relationships between the relative position and distance between the mandibular canal and third molar were investigated using χ2 -test and Fisher's exact test in Stata version 13. RESULTS: Within the Western Australian sample (N = 100), of six possible panoramic indicators of risk, two were significantly associated with contact between the tooth and mandibular canal on CBCT: (a) interruption of the radiographic white line of the canal; and (b) darkening of the root(s). CONCLUSIONS: Two panoramic radiograph risk signs are significantly more likely to indicate contact on the CBCT scans: interruption of the white line and darkening of the root(s). Further research is required to develop CBCT prescription guidelines for surgical planning.

The reliability of using postero-anterior cephalometry and cone-beam CT to determine transverse dimensions in clinical practice.

AIM: This study primarily aimed to assess the accuracy of classically-advocated reference points for the measurement of transverse jaw-base and dental relationships using conventional Postero-Anterior Cephalometry (PAC) and Cone-Beam Computed Tomography (CBCT). METHOD: PAC and CBCT images were collected from 31 randomly selected orthodontic patients (12 males, 19 females), all of whom had a full permanent dentition. The transverse widths of the maxilla, mandible and the dentition were measured using reference points on both image modalities. Confidence intervals, intra-class coefficients and Bland Altman plots were used to assess the measurement differences derived from the two acquirement methods. RESULTS: Measurements on PAC and CBCT images demonstrated statistically significant differences in the majority of the assessed variables. The interjugal (J-J) width was one of only two variables which did not demonstrate a statistically significant difference on image comparison. The mean differences of the antegonial width (Ag-Ag) (-4.44mm, 95% CI -5.38 to -3.51) represented the greatest difference between the imaging techniques. The application of these points to a transverse skeletal analysis (J-J/Ag-Ag ratio) revealed that five of the 31 subjects (16%) recorded 'false positive' readings according to the derived data. CONCLUSION: It is recommended that clinicians are cautious when interpreting and making decisions related to transverse dimensions derived from a PAC. The PAC has a higher tendency to falsely identify individuals who require maxillary expansion procedures based on conventional clinical criteria. The errors primarily associated with identifying structures which represent the width of the mandible are significant in both PAC and CBCT techniques and require further investigation. It is postulated that the confounding effects of overlying soft tissues have a sianificant impact on a clinician's ability to identify relevant landmarks.

The validity of transverse intermaxillary analysis by traditional PA cephalometry compared with cone-beam computed tomography.

AIM: To assess the validity of using jugale (J) and Antegonion (Ag) on Posterior-Anterior cephalograms (PAC) as landmarks for transverse intermaxillary analysis when compared with Cone Beam Computed Tomography (CBCT). MATERIAL AND METHODS: Conventional PAC and CBCT images were taken of 28 dry skulls. Craniometric measurements between the bilateral landmarks, Antegonion and Jugale, were obtained from the skulls using a microscribe and recorded as the base standard. The corresponding andmarks were identified and measured on CBCT and PAC and compared with the base standard measurements. The accuracy and reliability of the measurements were statistically evaluated and the validity was assessed by comparing the ability of the two image modalities to accurately diagnose an arbitrarily selected J-J/Ag-Ag ratio. All measurements were repeated at least 7 weeks apart. Intra-class correlations (ICC) and Bland-Altman plots were used to analyse the data. RESULTS: All three methods were shown to be reliable as all had a mean error of less than 0.5 mm between repeated measurements. When compared with the base standard, CBCT measurements were shown to have higher agreement (ICC: 0.861-0.964) compared with measurements taken from PAC (ICC: 0.794-0.796). When the arbitrary J-J/Ag-Ag ratio was assessed, 18 per cent of cases were incorrectly diagnosed with a transverse discrepancy on the PAC compared with the CBCT which incorrectly diagnosed 8.7 per cent. CONCLUSION: CBCT was shown to be more reliable in assessing intermaxillary transverse discrepancy compared with PAC when using J-J/Ag-Ag ratios.

The basic principles of radiological interpretation.

Radiologic interpretation is a complex process which involves the application of an appropriate algorithm in the study of radiologic images and the ability to understand the meaning and to weight the various findings, ultimately contributing to diagnosis. Prerequisites include the knowledge of orofacial radiologic anatomy and the various pathoses which may arise or manifest in this region of the body. An understanding of the strengths and limitations of the modality employed is also essential. The process of interrogating radiologic images for abnormalities varies, depending on the modality. This paper outlines the basic steps involved in the radiologic examination of abnormalities which affect the jaws, primarily in relation to plain 2-D imaging.

Cone beam imaging: is this the ultimate imaging modality?

This review article provides an overview of cone beam (CB) imaging technology and its role in orofacial imaging, including comparison with two-dimensional (2D) radiography and multislice computed tomography (MCT). The radiation dose levels of CB systems are discussed, with reference to those delivered by MCT and common dental 2D views. The large variation in dose levels delivered by CB systems and the importance of using ultra low-dose CB units are emphasized. Low-dose MCT protocols can be used. CB and MCT image quality are compared. CB is an essential technique that all dental and orofacial clinicians must be familiar with. Where ultra low-dose systems and protocols are used, CB imaging should be considered in day-to-day clinical practice. However, CB imaging is not the technique of choice in many clinical scenarios. Rather than replacing other modalities, CB imaging complements intraoral 2D radiography, panoramic radiography, MCT and other techniques including magnetic resonance imaging, ultrasound and nuclear medicine. MCT is a much more powerful and flexible modality and presently remains the technique of choice over CB imaging in many clinical scenarios. All radiologic examinations, including CB and MCT, should be comprehensively evaluated in entirety. The responsibilities and the radiological skill levels of clinicians involved in imaging as well as the associated ethical and medico-legal implications require consideration.