Lower Border (lower + border)

Distribution by Scientific Domains


Selected Abstracts


Metastatic cancer to the floor of mouth: the lingual lymph nodes,,

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 4 2002
Jay M. Dutton MD
Abstract Background The upper level of a cervical lymphadenectomy is anatomically defined at its anterior extent by the lower border of the mandible and, in surgical practice, by the lingual nerve. A neck dissection completed below this level is generally considered adequate for removal of lymph nodes at risk for metastases from oral cavity cancer. Traditional discontinuous neck dissections do not provide for removal of floor of mouth tissue along with the primary and neck specimens. Methods A case report presenting biopsies from a T2N2bM0 squamous cell carcinoma of the mobile tongue and adjacent floor of the mouth in a 73-year-old man. Results Deep biopsy of a ventral tongue and floor of mouth squamous cell carcinoma revealed occult metastatic cancer to lymph nodes located in the superficial floor of mouth associated with the sublingual gland above the lingual nerve. This report identifies floor of mouth lymph nodes that can be involved with cancer and missed through the standard practice of discontinuous neck dissection.Conclusions. This finding offers evidence that, in certain cases, a traditional discontinuous neck dissection may not address all lymph nodes at risk in the treatment of oral cavity cancer. Further investigation into lymph node distribution within the oral cavity is warranted to reappraise the upper limits of cervical lymphadenectomy. © 2002 Wiley Periodicals, Inc. Head Neck 24: 401,405, 2002; DOI 10.1002/hed.10026 [source]


Radicular cyst associated with a primary molar following pulp therapy: a case report

INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 6 2001
M. Takiguchi
Summary. A radicular cyst arising from the primary second molar and causing displacement of the permanent successor to the lower border of the mandible, with accompanying buccal expansion, was examined clinically and radiographically. Extraction of the primary molar and extirpation of the cyst led to uneventful healing. The primary molar had received pulp treatment with therapeutic agents approximately 1·5 years prior to the patient's first visit. The relationship between pulp treatment and rapid growth of the radicular cyst is discussed. [source]


Effects of a Mechanical Barrier on the Integration of Cortical Onlay Bone Grafts Placed Simultaneously with Endosseous Implant

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2002
Luiz Z. Salata DDS
ABSTRACT Background: Previous experimental studies on onlay bone graft integration have shown either advantages or disadvantages to the use of mechanical barriers. This indicates that the role played by the biologic properties of transplanted bone and membrane in graft revascularization and bone remodeling has not yet been established. The outcomes regarding osseointegration of titanium dental implants applied in such a condition are still contradictory. Purpose: The rabbit's radius model that is grafted onto the mandibular lower border and covered by membrane can reproduce a challenging experimental situation to preliminarily study the factors involved in osseointegration under deprived blood vessels source. Materials and Methods: Fourteen New Zealand White rabbits had a 2.5-cm segment of the right radius osteoectomized and fixed onto the right mandibular lower border using titanium screws. Two screw-shaped titanium implants (2.5 mm wide 2.5 mm long) were installed 7 mm apart in the mid length of the grafted bone. In experimental sites, the graft with the implants and graft-host bone junction were covered by expanded polytetrafluoroethylene (e-PTFE) membrane; control sites were left uncovered. Eight animals from the experimental group and six animals from the control group were sacrificed at 6 and 24 weeks after surgery. Ground sections obtained from en bloc tissues containing graft, implants, and recipient bone were subjected to histologic evaluation and histomorphometric analysis (area occupied by the graft and bone-to-implant contact). Results: The graft showed significantly more resorption after 24 weeks than at 6 weeks (p .05) irrespective of the treatment (with or without membrane), although the amount of new bone was greater at 24 weeks in sites where a membrane was covering the graft. Compared with 6 weeks postoperatively, the bone-to-implant contact was considerably improved at 24 weeks (p .05), and the membrane seemed beneficial for implant osseointegration when compared with unprotected sites (p .05). As a result of graft resorption, the amount of soft tissue was considerably expanded in sites beneath membrane, accompanied by a sustained process of trabecular bone deposition close to the barrier. Conclusions: Cortical onlay grafts covered by membrane demonstrated delayed remodeling, probably as a consequence of a hindered process of graft revascularization. Grafts covered by membrane might rely on previous host bone resorption both to become revascularized and to remodel. The findings that the membrane-protected grafts were most resorbed at 24 weeks might be attributable to better implant osseointegration, because the fixtures were exposed to greater mechanical stimulation in these sites. [source]


Evaluation of the visibility and the course of the mandibular incisive canal and the lingual foramen using cone-beam computed tomography

CLINICAL ORAL IMPLANTS RESEARCH, Issue 7 2010
Nikos Makris
Abstract Objectives: To assess the visibility and the course of the incisive canal and the visibility and the location of the lingual foramen using cone-beam computed tomography (CBCT). Methods: In total, 100 CBCT examinations of patients for preoperative planning were used for this study. The examinations were taken using the NewTom 3G CBCT unit, applying a standardized exposure protocol. Image reconstruction from the raw data was performed using the NewTom software. Three experts were asked to assess the visibility of the incisive canal using a four-point rating scale. The position of the incisive canal was recorded in relation to the lower, buccal and lingual border of the mandible using the application provided by the CBCT software. Results: The incisive canal was definitely visible in 83.5% of the scans and the mean endpoint was approximately 15 mm anterior to the mental foramen. The mean distance from the lower border of the mandible was 11.5 mm and its course was closer to the buccal border of the mandible in 87% of the scans. The lingual foramen was definitely visible in 81% of the scans. Conclusions: The high detection rate of the incisive canal and the lingual foramen in the anterior region of the mandible using CBCT indicates the potentional high preoperative value of CBCT scan for surgical procedures in the anterior mandible. To cite this article: Makris N, Stamatakis H, Syriopoulos K, Tsiklakis K, van der Stelt PF. Evaluation of the visibility and the course of the mandibular incisive canal and the lingual foramen using cone-beam computed tomography. Clin. Oral Impl. Res. 21, 2010; 766,771. doi: 10.1111/j.1600-0501.2009.01903.x [source]