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At least 163 records · Page 9Linked to original sources
PubMed1992

Densitometric evaluation of changes in the soft tissue of the chin and the lower lip during the treatment of Class III malocclusion.

The aim of this study was to use densitometry of lateral skull teleradiographs to evaluate the changes that occurred in the lower lip and chin after orthodontic or orthodontic-surgical treatment of Class III malocclusion. Forty teleradiographs from 20 patients with mandibular prognathism were made at the beginning and end of treatment. In ten of these patients the treatment was exclusively orthodontic with an edgewise appliance, and in another ten the treatment was orthodontic with a straight wire appliance combined with orthognathic and mentoplastic surgery. In the patients who were only treated orthodontically, a significant increase in density of the lower lip and the chin was found after treatment. This seemed to be related to an increase of muscular tension in these areas. Patients treated with orthognathic surgery and the straight wire appliance showed a decrease in density of the chin after treatment, but not of the lip. This can be interpreted as a consequence of muscular normalization after this procedure was accomplished.

Absorptiometry, Photon↗
PubMed2004

[Chin augmentation with bone transplantation from the mandible].

OBJECTIVE: To explore a new method for mentoplasty. METHODS: The bilateral prominent mandibular angle or outer lamina was resected through the intraoral approach. The resected bone fragments were shaped and rigid fixed to the chin with miniplates and screws. RESULTS: A total of 30 patients (28 females, 2 males) accepted chin augmentation with this method. The mandibular angle bone was used in 20 cases and the mandibular outer lamina was used in 10 cases. The operative results were satisfactory, and the patient's facial contour was improved substantially. CONCLUSION: No rejection reaction was found after this procedure. Chin augmentation with autogenous mandibular bone is an ideal method for genioplasty.

Adult↗
PubMedDate not supplied

Combining chin-jowl implants with local anesthesia facial rejuvenation.

Mandibular implantation is an outpatient procedure that can be used in combination with other minimally invasive cosmetic interventions. Specifically, silastic chin implants can help create a strong chin and smooth the jaw-line in carefully selected patients. A standard surgical excision tray plus a few additional simple instruments are required, and a variety of commercially available implants are available for placement via an intraoral or submental approach. Meticulous technique minimizes the small risk of nerve injury and numbness. Chin-jowl implants may be preceded by neck liposuction and immediately followed by a face-lift to achieve overall facial enhancement.

Anesthesia, Local↗
PubMed1990

Numb chin syndrome: a case report.

Neuropathy of the inferior alveolar nerve is common in dental practice. Its cause, when not a result of local anesthetic, is normally from dental disease or trauma. Isolated mental neuropathy (numb chin syndrome) is extremely uncommon, and its most common cause also is dental. The next most common cause is from an underlying neoplasm, and some cases have resulted from systemic disease (eg, multiple sclerosis). Some patients show no evidence of additional disease and experience spontaneous remission of the symptom. Numb chin syndrome cases require coordination of treatment between dentists and physicians. Since a disproportionate number of these cases present with a numb chin as the first symptom of a neoplasm, aggressive diagnosis is required. Careful follow up is important before dismissing it as a spontaneous remission. Dentists must be familiar with isolated mental neuropathy and its medical implications because they are likely to be the first health professionals that patients present to for diagnosis.

Adult↗
PubMed1989

Chin augmentation with various alloplastic materials: a comparative study.

This retrospective study of 62 patients compared three alloplastic materials used in chin augmentation: Proplast I (PI), Proplast II (PII), and porous block hydroxyapatite (PBHA). There were 25 patients with PI implants (average follow-up of 44.8 months), 25 patients with PII implants (average follow-up of 32.8 months), and 12 patients with PBHA implants (average followup of 19.1 months). Average bone resorption was 1.25 mm (range 0.00 to 3.30 mm) beneath the PI and PII implants and 0.00 mm beneath the PBHA implants. Average posterior settling was 0.46 mm (range 0.00 to 2.00 mm) for the PI and PII implants and 0.03 mm (range 0.00 to 0.17 mm) for the PBHA implants. The percentage of soft tissue change at pagonion relative to the size of the implant was 83.0% (range 66.7% to 100.0%) for PI and PII and 86.8% (range 77.3% to 100.0%) for the PBHA implants. When PI or PII implants were used, younger patients had more resorption than older patients. Slightly more resorption was found with PI and PII implants when maxillary surgery was performed. The size of the PI or PII implants made no difference in the amount of bone resorption, although there was slightly less soft tissue change when larger implants were used. Males had slightly more bone resorption than did females. The bone resorption beneath the PI and PII implants occurred within the first 12 months postsurgery. It can be concluded from this study that PI and PII implants are acceptable materials for chin implants, but some resorption can be expected during the first 12 months postsurgery. The absence of detectable resorption and the excellent soft tissue change make PBHA an attractive alternative as a chin implant material, although it is technically more difficult to use.

Adolescent↗
PubMed1987

[Methods for the evaluation of abnormalities of the bony chin with a view toward surgical correction].

The bony chin is not placed in its position by chance. As with the other skeletal pieces of the face, it is controlled by the major laws of craniofacial morphologic and functional equilibrium. Clinical evaluation of anomalies of position of the bony chin in the three spatial planes is not sufficiently precise, and craniofacial structural and architectural analysis is an essential aid for determining origin of the mental dystopia and surgical remedial means. The aim of the latter is to restore the bony chin to its position of craniofacial equilibrium, the only way to obtain a stable functional result.

Cephalometry↗
PubMed1994

[Multiple myeloma with numb chin syndrome as the initial manifestation].

The numb chin syndrome (NCS) is characterized by chin or lower lip numbness restricted to the distribution of the mental nerve (the distal trigeminal nerve). A case of multiple myeloma with polycythemia vera was diagnosed with NCS as the initial manifestation. A 73-year-old Japanese male was admitted to our hospital in April, 1993, because of paresthesia around the chin and lower lip. X-ray film showed multiple osteolytic lesions. According to serum and urine immunoelectrophoresis, lambda type Bence Jones protein was demonstrated. The bone marrow aspiration showed the normocellular marrow with 14.1% myeloma cells. He was diagnosed a suffering from multiple myeloma and was treated with melphalan and prednisolone. He is alive at present with resolution of NCS. We discussed pathogenesis, diagnosis, and treatment of NCS.

Aged↗
PubMed1997

[Extreme chin advancement with tandem genioplasty].

Chin correction is an important procedure in orthognathic and facial plastic surgery. Whereas simple genioplasty can be easily performed by sliding or jumping osteotomies, extreme chin advancement, i.e., an advancement greater than 10 mm, requires the use of the double-step sliding technique. Independent of the fixation technique chosen these bony segments tend towards instability when being pedicled on the periosteum and the posterior muscle attachments. The traction force of the geniohyoid, genioglossus and digastric muscles is responsible for the instability of the advanced segments. To compensate for this muscle force a special double-step osteotomy was developed that combines the sliding and jumping osteotomy and allows the positioning of the pedicled basal chin segment in front of the mandible. Using this new tandem genioplasty, six cases of retrogenia with an advancement of 16 to 20 mm were corrected. The only complications in one case was mild wound dehiscence of the mucous membrane of the mandible's frontal vestibulum.

Adolescent↗
PubMed1991

Chin rub CRs may reflect conditioned sickness elicited by a lithium-paired sucrose solution.

Rats were given a single conditioning trial in which 20% sucrose solution was paired with an intraperitoneal (IP) injection of lithium chloride (127.2 mg/kg), d-amphetamine (3 mg/kg) or physiological saline. Thirty min before a subsequent 10-min taste reactivity (TR) test and a 1-h conditioned taste avoidance (CTA) test the rats were injected IP with either the antiemetic agent, trimethobenzamide (5 mg/kg) [corrected] or with physiological saline solution. The lithium-paired, but not the amphetamine- or saline-paired, sucrose solution elicited the aversive TR responses of chin rubs, paw pushes and gapes. Trimethobenzamide suppressed the aversive TR response of chin rubs in the lithium-conditioned group, but not in a group given unconditionally aversive quinine solution. The CTA test was not sensitive to the antiemetic properties of trimethobenzamide, although the drug enhanced sucrose preference overall. The results suggest that chin rub responses may measure conditioned sickness.

Animals↗
PubMed1993

Biomechanical changes of the mandible from orthopaedic chin cup force studied in a three-dimensional finite element model.

Biomechanical changes of the mandible from orthopaedic chin cup forces were investigated by means of finite element analysis. A three-dimensional model of the mandible including the temporomandibular joint was developed for stress analysis in the mandible. A chin cup force of 400 gf was applied at pogonion on the mandible in the direction toward the condyle. From the stress analyses, it was revealed that (1) uniform tensile stresses were produced at the outer borders of the mandible, (2) compressive stresses were induced in the centre of the mandible, (3) compressive stresses were generated widely on the surface of the condyle, and (4) stresses on the condyle were smaller in magnitude than those in the mandibular corpus. These results coincide with morphological changes of the mandible revealed in previous studies and, thus, indicate an association of stresses with remodelling of the mandible from chin cup therapy applied to adolescent patients with mandibular prognathism.

Adolescent↗
PubMed1981

Chin advancement as an aid in correction of deformities of the mental and submental regions.

Six patients are presented demonstrating various uses of chin advancement (horizontal osteotomy of the mandibular symphysis and sliding advancement) for correction of mental and submental deformities. With preservation of muscular attachment to the posterior border of the advanced mandibular fragment, the author feels that there is an anterior pull on the cervical musculature that may complement the posterior pull of platysmal plication. The technique of chin advancement is described in detail and offers more versatility than the use of alloplastic chin implants. The author advocates the use of this direct osseous approach for purely aesthetic reasons as well as in the correction of maxillofacial and craniofacial malformations.

Adolescent↗
PubMed2003

Cervical osteotomy for the correction of chin-on-chest deformity in ankylosing spondylitis. Technical note.

The correction of chin-on-chest deformity is challenging and requires combined anterior and posterior approaches to the cervical spine. The authors describe a cervical osteotomy technique for the correction of chin-on-chest deformity in patients with ankylosing spondylitis (AS). This procedure can be accomplished using a posterior screw rod construct combined with an anterior hybrid plate system. In patients with AS, a "front-back-front" approach may be necessary because of the deformity's rigidity. The authors describe the complicated intubation and anesthetic requirements for this approach. They performed an anterior discectomy, cervical osteotomy, and unilateral pediculectomy but did not place anterior instrumentation. Via a posterior approach, laminectomies, facetectomies, and the contralateral pediculectomy were then undertaken. A posterior cervical screw/rod system was placed and loosely connected to titanium rods. Intraoperatively the deformity was corrected by placing the neck in extension combined with compression of the posterior screws on the rods. The posterior construct is then tightened. Finally, an anterior cervical approach is performed to place a structural interbody graft and a hybrid anterior cervical plate construct. The authors have successfully used this approach to correct a chin-on-chest deformity in a patient with ankylosing spondylitis. At 1-year follow-up examination, excellent resolution of the deformity and solid fusion had been achieved. They prefer to perform this procedure by using state-of-the-art anterior and posterior instrumentation systems.

Bone Plates↗
PubMed1995

Building the CHIN (community health information network) organization.

This article presents a template for establishing a community health information network (CHIN) and focuses primarily on the most popular organizational model for a CHIN, the community coalition model. Additionally, practical solutions to the challenges facing these organizations are presented, based on experiences with CHIN initiatives across the country.

Catchment Area, Health↗
PubMed1996

CHINs: information superhighway or unpaved byway?

In all successful systems it is the relationship--both formal and informal--that define how well organizations run and how they create value for their customers. Information systems' real benefit, therefore, is to add value to those relationships. No matter if the original business intent of the system was to speed delivery, cut costs, improve quality or provide integration of services, information systems' value resides in their ability to get the right people (not the computers) to talk to each other more efficiently and effectively. Take this simple premise, apply it to the creation of CHINs and ask, "What relationships matter and how can CHIN participation most effectively enhance those relationships for our medical group?" The answer, combined with the need to deliver high quality, lowest possible cost health care, is the goal of CHINs, as described in this professional paper.

Community Networks↗
PubMed2004

Treatment effects of chin cup appliance on mandible in Class III malocclusion: strain tensor analysis. A pilot study.

OBJECTIVE: The effects of chin cup therapy on the mandible in Class III malocclusions have been investigated extensively via cephalometric analyses. However, the actual sites of mandibular skeletal change are not detectable with conventional cephalometric analysis. It is important to elucidate the association between remodeling of the mandible with the mechanical stress applied with chin cup therapy. METHOD AND MATERIALS: In this study, the geometric morphometric changes in the mandible from chin cup force and/or growth were investigated using strain tensor analysis. RESULTS: This geometric morphometric analysis reveals that mandibular deformation arises partly due to a size change and partly due to a shape change. The direction and magnitude of principal vectors of the strain tensors may provide more information about this deformation. CONCLUSION: Strain tensor analysis may show the degree of transformation within the mandibular geometric configuration due to treatment effects and/or growth changes as seen on lateral cephalometric radiographs.

Bone Remodeling↗
PubMed2006

Redirecting the growth pattern with rapid maxillary expander and chin cup treatment: changing breathing pattern from oral to nasal.

AIM: This study was undertaken to assess the possibility of redirecting the growth pattern by using rapid maxillary expansion and a light-force chin cup for a short period of time, with limited patient cooperation, during the pre-growth and growth-spurt stages. METHODS: The study included a series of 60 patients, 24 males and 36 females from 7 to 14 years of age, with crossbite or midfacial deficiencies. Treatment involved wearing a chin cup 24 hours a day to force mouth closure during rapid maxillary expansion activation, which was 2 turns per day to rapidly expand the midpalatal suture and enhance nasal breathing. Lateral cephalograms and intraoral and facial photographs were taken 2 years before treatment, at the time of rapid maxillary expansion, 3 weeks following rapid maxillary expansion activation, 3 months after the cessation of rapid maxillary expansion activation, and 1 to 3 years post-rapid maxillary expansion activation. RESULTS: Despite the severity, the crossbite would always improve within 21 days following rapid maxillary expansion activation. The cephalograms and photographs demonstrated forward movement of the nasal bridge and maxilla, with backward rotation of the mandible. The bite depth remained nearly the same as pretreatment. CONCLUSION: The results suggested that 24 hours of light-force chin cup wear, while expanding the midpalatal suture, is the major factor to force mouth closure and enhance nasal breathing. As a result, there is advancement of the maxilla, avoidance of tongue encroachment upon the mandible, and deceleration of horizontal mandibular growth.

Adolescent↗
PubMedDate not supplied

Reconstruction of total lower lip and chin defects using the composite radial forearm--palmaris longus tendon free flap.

BACKGROUND: Functional and aesthetic restoration of total lip and chin defects can be achieved using the composite radial forearm-palmaris longus tendon free flap. OBJECTIVE: To present the technique we use and our experience with this form of reconstruction in 10 consecutive patients with total lip and chin defects who were surgically treated between 1992 and 1998. METHODS: The palmaris longus tendon acting as a sling over which the flap is draped is responsible for long-term maintenance of vertical lip height and lip support. The factors responsible for this are the long-term maintenance of vertical lip height and lip support and the transfer of facial muscle activity to the neolip. RESULTS: All patients were satisfied with their final reconstructive result. Oral competence for deglutition and speech was achieved in all patients in our case series, with no incidence of drooling. CONCLUSION: We recommend the use of the composite radial forearm-palmaris longus tendon free flap for this type of reconstructive surgery. Arch Facial Plast Surg. 2000;2:53-56

Aged↗
PubMed1998

Double free-flap reconstruction of massive defects involving the lip, chin, and mandible.

Two patients with massive, composite defects of the total lower lip, chin, and anterior mandible underwent double free-flap reconstruction. A fibular osteoseptocutaneous flap was used to reconstruct the mandible and floor of the mouth and a radial forearm fasciocutaneous composite flap, including the palmaris longus tendon, was used for total lower lip and chin reconstruction. Postoperatively, both patients had acceptable cosmesis, were orally competent, and recovered adequate mandibular function. Double free-flap reconstruction is indicated only in those circumstances in which composite tissue requirements or massive tissue defects preclude reconstruction with a single free-tissue transfer.

Adolescent↗