Three-dimensional measurement of radiographic bone-implant contact lengths of zygomatic implants in zygomatic bone: a retrospective study of 66 implants in 28 patients.

Zygomatic implant treatment is widely applied for severe maxillary atrophy to help rehabilitate the maxillary dentition. This retrospective study was performed to evaluate the actual radiographic bone-implant contact (rBIC) lengths of zygomatic implants. The records of 28 patients who underwent zygomatic implant surgery and subsequent follow-up examinations between August 2013 and September 2018 in the Department of Oral and Maxillofacial Surgery, Taipei Tzu Chi Hospital were reviewed. The surgeries were performed by a single surgeon using the same treatment protocol. All patients had a computed tomography scan at 1year after the surgery. Using three-dimensional imaging software, an investigator measured the rBIC lengths of 66 implants and documented their clinical status. The implant survival rate was 100%. The mean rBIC length was significantly longer in male patients than in female patients (20.80±5.88mm versus 17.79±6.34mm; P=0.028). The mean rBIC length of double zygomatic implants was significantly longer when compared to that of single implants (21.11±6.23mm versus 17.75±5.85mm; P=0.027). This article is novel in reporting the exact rBIC lengths of zygomatic implants in a clinical setting. The results showed that zygomatic implants are a viable treatment modality for full-mouth rehabilitation.

Treatment efficiency and stability of skeletal Class III malocclusion with a surgery-first approach.

OBJECTIVES: To compare treatment duration in skeletal Class III malocclusion patients managed with a 2-step treatment (surgery-first approach, SFA) and conventional 3-step treatment, and to compare stability of surgical outcomes between segmentation and non-segmentation in the 2-step treatment group. SETTING AND SAMPLE POPULATION: The sample population consisted of 37 patients who completed orthognathic surgery (OGS) and orthodontic correction at the Charm Aesthetic Surgery Clinic (Taipei, Taiwan) between 2012 and 2015. Of these, 26 received 2-step treatment and 11 received 3-step treatment. MATERIALS AND METHODS: To compare treatment efficiency and stability, three time points were analysed: T0 , before treatment (before OGS in the 2-step group and before orthodontic treatment in the 3-step group); T1 , after OGS but before orthodontic correction (cone beam computed tomography (CBCT) was obtained within 2 weeks of OGS); and T2 , after orthodontic correction (CBCT was obtained on the day of bracket removal). The post-OGS (T1 ) CBCT items were individually superimposed on the pre-treatment (T0 ) CBCT items to determine the distance of B point migration. RESULTS: A significant difference was found in treatment times between 2-step treatment and conventional 3-step treatment. In addition, no significant difference was found when comparing B-X (mm) and B-Y (mm) at T2 -T1 for the segmentation and non-segmentation groups. CONCLUSIONS: Using SFA for skeletal Class III malocclusions saves approximately 6 months of treatment time over 3-step treatment; the stability of the segmentation group was comparable to that of the non-segmentation group, a result that is possibly associated with the fixation of 2 miniplates.

Nasopharyngeal carcinoma metastatic to the mandible.

Nasopharyngeal carcinoma (NPC) is one of the most common malignancies in the head and neck region, especially among those of Chinese origin. NPC has multifactorial aetiologies including genetic susceptibility, consumption of food with high salt content, and the Epstein-Barr virus. The primary tumour usually arises from the lateral walls of the nasopharynx and is characterized by a rich sub-mucosal lymphatic structure, often leading to cervical lymph node metastasis. Distant metastasis has been recognized to be a major cause of treatment failure in patients with nasopharyngeal carcinoma. Bone, liver and lung are the most frequent sites of NPC metastases.

Up-regulation of a serine-threonine kinase proto-oncogene Pim-1 in oral squamous cell carcinoma.

The Pim-1 proto-oncogene, encoding a serine-threonine kinase, has been found to play an important role in regulating apoptosis, differentiation, proliferation and tumourigenesis. The present study was conducted to assess the importance of Pim-1 in oral tumourigenesis in vivo. Reverse transcriptase-polymerase chain reaction and immunohistochemistry were used to study the expression of Pim-1 in oral squamous cell carcinoma (OSCC) and non-cancerous match tissue (NCMT) sampled from the periphery of the tumours. Pim-1 mRNA expression in OSCC was significantly higher than that in NCMT in 36 tissue pairs (1.33+/-0.41 versus 0.97+/-0.29, P=0.03). The percentage of OSCCs exhibiting strong cytoplasmic Pim-1 immunoreactivity was significantly higher than that of NCMT (60% versus 19%, P=0.007). Pim-1 immunoreactivity is higher in the more differentiated components of a tumour. In around 10% of OSCC cases, Pim-1 immunoreactivity was found in the nucleus as well. These results show novel findings of the up-regulation of Pim-1 expression from NCMT to OSCC. The pathogenetic role of Pim-1 expression in oral tumourigenesis deserves further investigation.