Reducing Target Volumes of Intensity Modulated Radiation Therapy After Induction Chemotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma: Long-Term Results of a Prospective, Multicenter, Randomized Trial.

PURPOSE: The objective of this study was to estimate the long-term survival, late toxicity profile, and quality of life of patients with locoregionally advanced nasopharyngeal carcinoma (NPC) treated with combined induction chemotherapy (IC) and concurrent chemoradiotherapy from a clinical trial focused on reducing the target volume of intensity modulated radiation therapy (IMRT). METHODS AND MATERIALS: This prospective, randomized clinical trial was conducted across 6 Chinese hospitals and included 212 patients with stage III-IVB NPC who were randomly allocated to a pre-IC or post-IC group. Eligible patients were treated with 2 cycles of IC + CCRT. All patients underwent radical IMRT. Gross tumor volumes of the nasopharynx were delineated according to pre-IC and post-IC tumor extent in the pre-IC and post-IC groups, respectively. RESULTS: After a median follow-up of 98.4 months, 32 of 97 (32.9%) and 33 of 115 (28.7%) patients experienced treatment failure or died in the pre-IC and post-IC groups, respectively. None of the patients developed grade 4 late toxicity. Late radiation-induced toxicity predominantly manifested as grade 1 to 2 subcutaneous fibrosis, hearing loss, tinnitus, and xerostomia, whereas grade 3 late toxicity included xerostomia and hearing loss. The 5-year estimated overall, progression-free, locoregional recurrence-free, and distant metastasis-free survival rates in the pre-IC and post-IC groups were 78.2% versus 83.3%, 72.0% versus 78.1%, 90.2% versus 93.5%, and 78.1% versus 82.1%, respectively. The pre-IC group had a significantly higher incidence of xerostomia and hearing damage than the post-IC group. In terms of quality of life, compared with the pre-IC group, the post-IC group showed significant improvement in cognitive function (P = .045) and symptoms including dry mouth (P = .004), sticky saliva (P = .047), and feeling ill (P = .041). CONCLUSIONS: After long-term follow-up, we confirmed that reducing the target volumes of IMRT after IC in locoregionally advanced NPC showed no inferiority in terms of the risk of locoregional relapse and potentially improved quality of life and alleviated late toxicity.

Concrescence of maxillary second molar and impacted third molar: A case report.

BACKGROUND: Morphological anomalies of teeth, including talon cusp, dens evaginatus, gemination, fusion, concrescence, root dilaceration, and taurodontism, always involve changes in the enamel, cementum and dentin. Diagnosing concrescent teeth through routine clinical examination alone is difficult, and most cases of concrescence are found accidentally during extraction. A definite preoperative diagnosis of concrescence would contribute to a better treatment plan and fewer undesirable complications. CASE SUMMARY: A 47-year-old woman who complained of left maxillary first molar loss for half a year presented to our department seeking treatment by dental implant restoration. Panoramic radiography and cone-beam computed tomography (CBCT) showed an unclear boundary between the distal root of the second molar and the mesial root of the third molar. The teeth were extracted under local anesthesia, and a definite diagnosis of concrescence was made by histopathological examination. CONCLUSION: CBCT is a useful tool for diagnosing and planning the management of tooth concrescence and may be beneficial for reducing unnecessary complications.

[Effects of body-shade resin layer thickness on the color of polyetheretherketone-Crea.lign restorations].

OBJECTIVE: This study aims to assess the effects of the different thicknesses of body-shade resin layers on the color of polyetheretherketone (PEEK)-Crea.lign restorations. METHODS: Five PEEK specimens with the thickness of 0.6 mm were prepared. The color values of PEEK specimens were measured. Afterward, opaque-shade resin layers (0.1 mm) and body-shade resin layers (1.5 mm) were stacked with mold. The five specimens were evenly ground to a thickness of 1.4, 1.2, 1.0, 0.8, 0.6, 0.4, 0.2, and 0.0 mm in sequence. After grinding and ultrasonic cleaning, the color value was measured. RESULTS: With the constant thickness of PEEK and 0.1 mm thickness of opaque-shade resin layer, the L*, a*, and b* values all showed downward trend with the increased thickness of the body-shade resin layer (1.0-1.4 mm). With the constant thickness of PEEK and 0.1 mm thickness of opaque-shade resin layer, the color difference between the adjacent groups was less than 1.5 NBS. This difference between nonadjacent groups was more than 1.5 NBS when the thickness of the body-shade resin layer reached 0.6 mm. Color difference between PEEK-Crea.lign restoration and PEEK was more than 1.5 NBS. CONCLUSIONS: The thickness change in the body-shade resin layers influence the color of the PEEK-Crea.lign restorations. Using A2 shade Crea.lign, opaque-shade resin layer thickness is 0.1 and 0.6 mm thickness of body-shade resin layer can produce color which clinically acceptable.