Photoacoustic Imaging for Noninvasive Periodontal Probing Depth Measurements.

The periodontal probe is the gold standard tool for periodontal examinations, including probing depth measurements, but is limited by systematic and random errors. Here, we used photoacoustic ultrasound for high-spatial resolution imaging of probing depths. Specific contrast from dental pockets was achieved with food-grade cuttlefish ink as a contrast medium. Here, 39 porcine teeth (12 teeth with artificially deeper pockets) were treated with the contrast agent, and the probing depths were measured with novel photoacoustic imaging and a Williams periodontal probe. There were statistically significant differences between the 2 measurement approaches for distal, lingual, and buccal sites but not mesial. Bland-Altman analysis revealed that all bias values were < ±0.25 mm, and the coefficients of variation for 5 replicates were <11%. The photoacoustic imaging approach also offered 0.01-mm precision and could cover the entire pocket, as opposed to the probe-based approach, which is limited to only a few sites. This report is the first to use photoacoustic imaging for probing depth measurements with potential implications to the dental field, including tools for automated dental examinations or noninvasive examinations

Clinical applications of custom-made vaginal cylinders constructed using three-dimensional printing technology.

PurposeThree-dimensional (3D) printing technology allows physicians to rapidly create customized devices for patients. We report our initial clinical experience using this technology to create custom applicators for vaginal brachytherapy.Material and methodsThree brachytherapy patients with unique clinical needs were identified as likely to benefit from a customized vaginal applicator. Patient 1 underwent intracavitary vaginal cuff brachytherapy after hysterectomy and chemotherapy for stage IA papillary serous endometrial cancer using a custom printed 2.75 cm diameter segmented vaginal cylinder with a central channel. Patient 2 underwent interstitial brachytherapy for a vaginal cuff recurrence of endometrial cancer after prior hysterectomy, whole pelvis radiotherapy, and brachytherapy boost. We printed a 2 cm diameter vaginal cylinder with one central and six peripheral catheter channels to fit a narrow vaginal canal. Patient 3 underwent interstitial brachytherapy boost for stage IIIA vulvar cancer with vaginal extension. For more secure applicator fit within a wide vaginal canal, we printed a 3.5 cm diameter solid cylinder with one central tandem channel and ten peripheral catheter channels. The applicators were printed in a biocompatible, sterilizable thermoplastic.ResultsPatient 1 received 31.5 Gy to the surface in three fractions over two weeks. Patient 2 received 36 Gy to the CTV in six fractions over two implants one week apart, with interstitial hyperthermia once per implant. Patient 3 received 18 Gy in three fractions over one implant after 45 Gy external beam radiotherapy. Brachytherapy was tolerated well with no grade 3 or higher toxicity and no local recurrences.ConclusionsWe established a workflow to rapidly manufacture and implement customized vaginal applicators that can be sterilized and are made of biocompatible material, resulting in high-quality brachytherapy for patients whose anatomy is not ideally suited for standard, commercially available applicators

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

Ultrasonographic characterization of lingual structures pertinent to oral, periodontal, and implant surgery

ObjectivesIncreased applications of ridge augmentation in the lingual posterior mandible call for an urgent need to study its anatomy. Therefore, our first aim was to validate ultrasound in measuring the mandibular lingual structures in human cadavers. Secondarily, to test its feasibility in imaging the lingual nerve in live humans.Materials and methodsNine fresh un- embalmed fully/partially edentulous cadaver heads were utilized for aim 1. Three areas in the lingual mandible were imaged (mandibular premolar, molar, and retromolar). Immediately after, biopsies were harvested from each site. The thickness of the mucosa, mylohyoid muscle, and lingual nerve diameter was measured via ultrasound and statistically compared to histology. Similarly, the lingual nerve in live humans was also imaged.ResultsNone of the differences between the ultrasound and histology measurements reached statistical significance (p > .05). The mean mucosal thickness via ultrasound and histology was 1.45 ± 0.49 and 1.39 ± 0.50 mm, 5 mm lingual to the mylohyoid muscle attachment. At 10 mm beyond the attachment, the ultrasound and histologic values were 1.54 ± 0.48 and 1.37 ± 0.49, respectively. The mean muscle thickness measured via ultrasound and histology was 2.31 ± 0.56 and 2.25 ± 0.47 mm, at the 5 mm distance. At the 10 mm distance, the measurements were 2.46 ± 0.56 and 2.36 ± 0.5 mm, respectively. The mean ultrasonic lingual nerve diameter was 2.38 ± 0.44 mm, versus 2.43 ± 0.42 mm, with histology. The lingual nerve diameter on 19 live humans averaged to 2.01 ± 0.35 mm (1.4- 3.1 mm).ConclusionsWithin its limitations, ultrasound accurately measured mandibular lingual soft tissue structures on cadavers, and the lingual nerve on live humans.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154973/1/clr13573_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154973/2/clr13573.pd

Enhanced near infrared optical access to the brain with a transparent cranial implant and scalp optical clearing.

We report on the enhanced optical transmittance in the NIR wavelength range (900 to 2400 nm) offered by a transparent Yttria-stabilized zirconia (YSZ) implant coupled with optical clearing agents (OCAs). The enhancement in optical access to the brain is evaluated upon comparing ex-vivo transmittance measurements of mice native skull and the YSZ cranial implant with scalp and OCAs. An increase in transmittance of up to 50% and attenuation lengths of up to 2.4 mm (i.e., a five-fold increase in light penetration) are obtained with the YSZ implant and the OCAs. The use of this ceramic implant and the biocompatible optical clearing agents offer attractive features for NIR optical techniques for brain theranostics