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At least 901 records · Page 50Linked to original sources
PubMed2000

Altered sensation associated with implants in the anterior mandible: a prospective study.

STATEMENT OF PROBLEM: Reported incidences of altered sensation after placement of mandibular implants range from a low of 0% to almost 44%, making it difficult to advise subjects regarding risk. PURPOSE: This study involved presurgical and postsurgical assessment of sensation in the lips and chins of 75 subjects, all of whom objectively demonstrated normal sensation before surgery. MATERIAL AND METHODS: Objective and subjective tests were administered before, and at planned intervals for 12 months after, the placement of 2 implants in the anterior mandible. RESULTS: Objective changes were observed in only 1 subject and then only at the 2-week postsurgery interval. There were significant differences for all subjects in subjective sensation changes from baseline to 2 weeks after surgery (P =.007) and from 2 weeks to 6 months (P =.003) or 12 months (P =. 003). There was a higher percentage of subjects with normal sensation before surgery who reported sensory changes 2 weeks after implant placement (34% vs 24% for all subjects), but only 1% of subjects still reported altered sensation 1 year later. Although there were no significant differences between men and women in reports of altered sensation, more women than men noted sensation changes 2 weeks after implants were placed (25% vs 13%). There appeared to be no relationships among gender, the degree of ridge resorption, and reports of altered sensation. CONCLUSION: Thus, although approximately 24% of subjects may report altered sensation in the short-term after implant surgery in the anterior mandible, the problem appears to be a transient one, with only about 1% experiencing sensation changes 1 year after implant surgery.

Adult↗
PubMed1975

The effects of variations in the opposing dentition on changes in the partially edentulous mandible. Part II. Densitometric measurements.

Distal-extension lower removable partial dentures were used to study the effects of various types of opposing dentitions on the residual mandibular ridge. The opposing-dentition groups included complete upper dentures, removable partial upper dentures, and natural teeth. Changes in the bone of the lower residual ridge were measured by means of densitometry. A significant densitometric difference was found in the bone of the partially edentulous mandible between the group of subjects wearing complete upper dentures and the group with natural upper teeth. The reason for this difference is uncertain; however, several theories can be offered. These are (1) an inherent bone difference between the subjects in the two groups, implying a difference in the bone of the group that retained their natural upper teeth longer than did the complete denture group, (2) an increased frequency and/or duration of muscle pull on the mandible due to clenching of the teeth to stabilize the upper complete denture, and (3) the possibility of coincidence. None of the densitometric changes measured at +18 months was significant.

Absorptiometry, Photon↗
PubMed1996

A color-enhanced aid for location of the transverse horizontal opening and closing axis of the mandible.

This article describes the use of a device for assisting in identification of the direction of the arc of rotation while locating the transverse horizontal opening and closing axis of the mandible. Translucent disks are mounted on the point of the styli of a kinematic face-bow and centering magnets are aligned with them, with no overlapping of the colors. The direction of the arcing movement is enlarged by the overlapping of the translucent disk over the centering magnet. The different color value generated by the overlapping identifies the arcing direction. After correction on the microadjustable arm, the centering magnet is realigned on the translucent disk. This sequence is repeated until the disk no longer overlaps with the centering magnet during the opening and closing movements of the mandible. This device uses the different color generated by mixing the color of the disk against a template of darker color. The disk enlarges the point of the stylus, thus magnifies the direction of the arc of rotation, and potentially reduces the clinical time necessary to locate the points of pure rotation.

Biomechanical Phenomena↗
PubMed1997

Titanium osseointegrated implants combined with hyperbaric oxygen therapy in previously irradiated mandibles.

STATEMENT OF PROBLEM: Treatment for head and neck malignancies commonly involves radiation therapy. As a result of this therapy the vascular supply to irradiated structures is altered and results in decreased tissue perfusion. In addition to vascular changes, bony structures undergo a reduction in osteoblastic and osteoclastic activity. These tissue alterations, especially in the mandible, enhance the risk of osteoradionecrosis. To avoid this occurrence, many patients who have undergone radiation therapy do not receive elective preprosthetic surgeries, including implant therapy. PURPOSE OF STUDY AND METHODS: This report presents the preliminary results of placing 18 titanium screw implants into previously irradiated mandibles in conjunction with hyperbaric oxygen therapy. RESULTS: Of the 18 implants placed, 17 (94%) were judged to be osseointegrated at the abutment connection. One implant did not receive an abutment and was "put to sleep." The remaining 16 (88%) were used for prosthetic rehabilitation. CONCLUSION: The use of implants in irradiated tissues may provide a means of enhancing prosthetic rehabilitation while reducing the risk of tissue trauma that may develop into osteoradionecrosis.

Adolescent↗
PubMed2006

[Medial cleft of the tongue, the lower lip and the mandible].

INTRODUCTION: The oro-facial clefts are very frequent congenital malformations, with many clinical forms. We report an exceptional case of median cleft of the tongue, the lower lip and the mandible. CASE REPORT: Our patient was a new born, admitted in our unit for major facial malformation with swallowing disorder. The patient presented a particular form of cleft no 30 in Tessier's classification, which associated two hemi-tongues, two hemi-lower lips and two hemi-mandibles. Surgery was performed early because of the swallowing disorder. Cosmetic and functional results were positive, with 18 month follow-up. DISCUSSION: With a review of the literature, we describe this pathology, its embryologic origin, its different clinical forms and its treatment.

Deglutition Disorders↗
PubMed1994

Distribution of injected dexamethasone from the buccal vestibule of the rat mandible.

Thirty-six Sprague-Dawley rats were divided into three groups of 12. Group 1 was a control, whereas group 2 had the dental pulp of the first mandibular molar acutely exposed, and group 3 had dental pulp exposure for 10 days. All animals were injected with 125I-labeled dexamethasone phosphate into the right mandibular vestibule. Each group of 12 was divided into subgroups of 4 and sacrificed at 1, 2, or 4 h. The soft tissue on the buccal side and the mandible with the molars were collected and the radioactivity determined. Dexamethasone was absorbed from the injection site and distributed to the ipsilateral mandible and to the contralateral muscle and bone similarly, regardless of the treatment. Results also indicate a possible osseous affinity for this steroid, which could be beneficial in relieving the pain of intraosseous endodontic flare-ups.

Administration, Buccal↗
PubMed1995

Tissue reaction to implanted super-EBA and mineral trioxide aggregate in the mandible of guinea pigs: a preliminary report.

In vitro sealing ability and biocompatibility tests on mineral trioxide aggregate (MTA) have shown similar or better properties for this material than for existing root-end filling substances. The purpose of this study was to examine the tissue reaction of implanted Super-EBA and MTA in the mandibles of guinea pigs. After anesthetizing seven guinea pigs, raising a tissue flap and preparing two bony cavities, the test materials were placed in Teflon cups and implanted in the mandibles. Two bony cavities without implanted materials were left to heal and used as negative controls. The presence of inflammation, predominant cell type, and thickness of fibrous connective tissue adjacent to each implant was recorded. The tissue reaction to MTA implantation was slightly than that observed with Super-EBA implantation. Based on these results , it seems that both Super-EBA and MTA are biocompatible.

Aluminum Compounds↗
PubMed1998

Tissue reaction to implanted root-end filling materials in the tibia and mandible of guinea pigs.

The purpose of this study was to examine the tissue reaction to implanted mineral trioxide aggregate (MTA), amalgam, Intermediate Restorative Material, and Super-EBA in the tibias and mandibles of guinea pigs. After anesthetizing 20 guinea pigs, raising tissue flaps, and preparing bony cavities, the test materials were placed in Teflon cups and implanted in the tibias and 10 days later in the mandibles. The animals were euthanized 80 days later and the tissues prepared for histological examination. The presence of inflammation, predominant cell type, and thickness of fibrous connective tissue adjacent to each implant were recorded. The tissue reaction to MTA implantation was the most favorable observed at both sites; as in every specimen, it was free of inflammation (p < 0.01). In the tibia, MTA was the material most often observed with direct bone apposition. Based on these results, MTA seems to be a biocompatible material.

Aluminum Compounds↗
PubMed1998

Inferior alveolar nerve function after sagittal split osteotomy of the mandible: correlation with degree of intraoperative nerve encounter and other variables in 496 operations.

Dysfunction of the inferior alveolar nerve indicated by various degrees of numbness of the lower lip and chin is one of the few drawbacks of sagittal split osteotomy (SSO) of the mandible. Although it has been recorded throughout the history of this technique its true aetiology is poorly understood. In this study of 496 SSOs, we have evaluated possible correlations between neurosensory dysfunction and several variables that have been implicated, such as the age of the patient, mandibular movement, type of split technique and osteosynthesis, degree of intraoperative nerve encounter, and surgical skill. Nerve dysfunction developed after 200/496 SSOs (40%). The patient's age had a significant influence on the recovery of the neurosensory function. Intraoperative nerve encounter such as nerve manipulation correlated with dysfunction to a much lesser degree than expected. Surgical skill seemed to influence the recovery of neurosensory function after SSO, which is often referred to as a technique-sensitive procedure. We suggest that the dissection of the soft tissue on the medial aspect of the mandibular ramus might be partly responsible for nerve dysfunction of the lower lip and chin after SSO of the mandible.

Adolescent↗
PubMed2000

Use of short endosseous implants and an overdenture in the extremely resorbed mandible: a five-year retrospective study.

PURPOSE: A retrospective study was performed to assess the success of short endosseous implants in combination with an implant-retained overdenture in the extremely resorbed mandible. PATIENTS AND METHODS: Patients included had a mandible not exceeding a median height of 12 mm measured on a standardized lateral cephalometric radiograph. Seventeen patients (14 women, 3 men; mean age, 65 years) with 68 endosseous implants were clinically and radiographically evaluated. RESULTS: During the follow-up period (mean, 77 months; range, 60 to 97 months), 8 implants were lost, bringing the cumulative survival rate to 88%. The peri-implant tissues were in good condition, and the bone loss around the implants was minimal. CONCLUSION: Because of the relative simplicity and low morbidity of this treatment strategy, it is a justified treatment option.

Aged↗
PubMed1992

Simultaneous split-thickness skin grafting and placement of endosteal implants in the edentulous mandible: a preliminary report.

Reconstruction of the edentulous atrophic mandible continues to be a treatment problem for the oral and maxillofacial surgeon. Clearly, endosteal osseointegrated implants are indicated for rehabilitation, but a total implant-supported prosthesis may not always be possible. The implant-supported overdenture is an excellent alternative, but modifications of the unfavorable residual ridge may be necessary. Attached crestal soft tissue, resistant to mechanical trauma, and improvement of the residual ridge anatomy are provided by adding a split-thickness skin graft vestibuloplasty (VSG) and lowering of the floor of the mouth (LFM). Simultaneous VSG and LFM with placement of endosteal implants provides the optimal condition for maximal rehabilitation of the atrophic mandible with specific indications. Results of four skin grafts and eight implants simultaneously placed are reported.

Alveoloplasty↗
PubMed1996

Histologic and microradiologic comparison of block and particulate cancellous bone and marrow grafts in reconstructed mandibles being considered for dental implant placement.

PURPOSE: Patterns of healing were investigated in mandibles reconstructed with three different techniques to assess their readiness for implant placement. PATIENTS AND METHODS: The subjects were 10 patients who had undergone mandibular reconstruction with either nonvascularized iliac block bone grafts (group 1; 3 patients), particulate cancellous bone and marrow (PCBM) grafts (group 2; 3 patients) for mandibular discontinuity, or PCBM grafts for mandibular marginal defects (group 3; 4 patients). Six (groups 2 and 3) or 12 months (group 1) after mandibular reconstruction, bone biopsy specimens were obtained for histologic examination with a trephine bur. As controls, bone specimens were obtained from ungrafted mandibles of patients undergoing dental implant placement. Undecalcified specimens were embedded in polyester resin and examined by routine light microscopy and microradiography. RESULTS: The morphology of the specimens from group 1 was similar to that of group 2, but not to that of the control subjects. However, the morphology of specimens from group 3 was generally similar to that of control subjects. CONCLUSION: These results suggest that mandibular reconstruction with PCBM grafts allows the placement of dental implants sooner than reconstruction with block bone grafts.

Adult↗
PubMed1996

Linear and angular measurements of the mandible during maximal mouth opening.

PURPOSE: There are numerous reports of the translatory movement of the condyle in maximal mouth opening; however, the rotatory movement is less well understood. The purpose of this study was to investigate the rotatory condylar movement and the factors associated with it in normal subjects. PATIENTS AND METHODS: To study the role of facial morphology in maximal mouth opening, linear and angular measurements of the mandible in both the closed and maximal open positions were made by means of cephalometry. Dental students, 29 men and 31 women with no functional disorders of the masticatory system, were investigated. RESULTS: When the mouth was fully opened, the linear measurement of condylar movement was 20.5 +/- 4.0 mm in men and 18.1 +/- 2.5 mm in women, and the angular measurements of the rotation of the mandibular ramus were 39.1 +/- 5.9 degrees in men and 36.3 +/- 4.3 degrees in women. These differences were statistically significant (P < .01). CONCLUSIONS: During condylar movement and rotation of the mandible, mandibular length and the inclination of the mandibular ramus in the former, and the inclination of the mandibular ramus, the mandibular angle and the position of the condyle in the latter, were important factors.

Adult↗
PubMed1999

Intraoral widening and lengthening of the mandible in baboons by distraction osteogenesis.

PURPOSE: The purpose of this study was to analyze the skeletal and dental positional changes and histomorphology of the distraction regenerates and mucogingival periosteal tissues that occurred after simultaneous widening and bilateral lengthening of the mandible in baboons by a miniaturized intraoral bone-borne distraction appliance. MATERIALS AND METHODS: Distraction appliances were activated 5 days after vertical ramus and symphyseal osteotomies at a rate of 0.9 mm/d for 10 days. The appliances were then stabilized for 8 weeks, after which the animals were killed. The distraction gaps and gingival tissues were analyzed clinically, histologically, and by standardized radiographic studies. RESULTS: Positional changes of the canines and incisor apices were proportional to the skeletal movements. Tipping of both incisors toward the center of the distraction gap was observed. Proportionate movement of the superior and inferior portion of the distracted segments was noted. Newly formed longitudinal trabecular columns parallel to the vector of distraction originated from the intact margins of alveolar bone contiguous with the adjacent teeth. Active histogenesis occurred in the stretched mucogingival periosteal tissues located in the distraction gaps. CONCLUSIONS: The results of this investigation support the clinical use of the miniaturized intraoral bone-borne distraction appliance to selectively widen and lengthen the mandible. The orientation of the mandibular distractors must be parallel to the common vector of distraction, which should be parallel to the maxillary occlusal plane. The formation of a bone regenerate in the alveolar region depends on the presence of an adequate bone interface on either side of the distraction gap.

Alveolar Process↗
PubMed1977

Absolute augmentation of the mandible.

In spite of all the attempts that have been made so far to bring about an absolute augmentation of the mandible, this procedure remains more or less at the experimental stage. The greatest difficulty in the known techniques is that the transplanted bone is resorbed to a great extent in a relatively short time. In the last 2 years at our department we have developed a new technique in which the resorption has up to now been minimal. Bone is no longer transplanted subperiosteally on the alveolar process, but the resorbed mandible is split into cranial and caudal portions from the region of the left 3rd molar to the region of the right 3rd molar, and between these two fragments the bone transplant is placed. In this way the resorption after 2 years is practically nil and, moreover, the patient can wear a normal prothesis.

Atrophy↗
PubMed1979

Changes in bone mass in rat mandibles after tooth extraction.

An experimental study concerning changes in bone mass in trabecular bone of mandibles on rats after extractions of upper molars has been carried out. The material consisted of 32 SPF Wistar rats, fed on Nafag-184 only. Experimental and control groups consisted of eight females and eight males, each group having same average weight with respect to sex at the age of 16 weeks. At this age the upper right molars were extracted on all rats in the experimental group. The rats were sacrificed after 16 weeks. Identical increase in weight within each sex group was found. Microradiograms of two buccal-lingual 100-mu-thick ground sections at a distance of 0.5 mm through the first molar in each side of the mandible were used. Quantitation of bone mass (bone area in percent) of a trabecular bone was done by electronic point counting. No significant difference in bone mass was found between left and right sides in the control group (P greater than 0.50), whereas a significant difference was found between left and right sides in the experimental group (P approximately 0.0001) with lowest mean value in right sides. Conclusively the analysis shows that local reduction in bite force causes osteoporotic changes in trabecular bone of the jaw.

Animals↗
PubMed1980

Reconstruction of mandible with pedicle bone grafts.

Three cases of pedicle bone grafts used to reconstruct the mandible are presented. The grafts were taken from the shoulder blade, rib and clavicle. In two patients partial and in one patient total mandibles were reconstructed. Good results were obtained.

Bone Transplantation↗
PubMed1982

An odontogenic myxofibroma related to an embedded third molar of the mandible. Report of a case.

A case of odontogenic myxofibroma involving the angle of the mandible is reported. This case arose in the area closely associated with the pericoronal portion of the embedded third molar. When the mandible resected was histopathologically examined, the tumor mass containing various shapes of epithelial cell nests and amorphous calcified bodies in the myxomatous fibrous tissue was found to be formed in the localized area well-demarcated by the enamel of the embedded tooth. These findings strongly suggest that this lesion is of odontogenic origin.

Female↗