Biomedical subjects

H M Rosen

Publications and source records attributed to H M Rosen.

At least 19 recordsLinked to original sources

PubMed1995

Aesthetic guidelines in genioplasty: the role of facial disproportion.

It has been demonstrated previously that many individuals requesting chin enlargement have small or retruded mandibles. A weak chin may be only one aspect of this particular class II skeletal deformity, the other components being a procumbent, retrusive lower lip, excessive labiomental fold depth, and decreased to normal lower face height. To avoid unaesthetic results, the chin should not be advanced beyond the retrusive lower lip, the only component over which osseous genioplasty has no control. This may result in residual sagittal "weakness" of the lower face, for which visual compensation can be achieved by vertical overelongation of the chin. Thirty-two patients requesting chin enlargement presented with the aforementioned class II deformity. Twenty patients had decreased lower face height and 12 patients had normal lower face height. Preoperative soft-tissue cephalometric analysis documented physical findings. The extent of sagittal chin movement was planned to advance the soft-tissue pogonion no further than the lower lip. Vertical chin movement was intentionally designed to overelongate the lower face relative to the midface in all patients. Radiographs were repeated at a mean 8.2 months following surgery to document skeletal displacements. Mean chin advancement was a modest 4.2 mm (2- to 7-mm range), and chin vertical displacement was a mean 7.9 mm (5.5- to 9-mm range). All patients had residual sagittal disproportion of the pogonion relative to the subnasale (-7.6 mm mean) and newly created vertical disproportion with mean lower face heights of 69.8 mm compared with mean midface heights of 64 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Occlusal plane rotation: aesthetic enhancement in mandibular micrognathia.

Patients afflicted with extreme degrees of mandibular micrognathia typically have vertically deficient rami as well as sagittally deficient mandibular bodies. This results in deficient posterior facial height, an obtuse gonial angle, excessively steep occlusal and mandibular planes, and a compensatory increase in anterior facial height. The entire maxillomandibular complex is overrotated in a clockwise direction. Standard orthognathic surgical correction fails to address this rotational deformity. As a consequence, the achieved projection of the lower face is inadequate, posterior facial height is further reduced, and occlusal and mandibular planes remain steep. Eleven patients with severe mandibular micrognathia underwent a surgical correction involving occlusal plane rotation to its normal orientation relative to Frankfort horizontal. This was accomplished by Le Fort I osteotomy to shorten the anterior maxilla (creating open bites in seven patients and making preexisting open bites worse in four patients) and sagittal split ramus osteotomies to advance and rotate the mandibular body counterclockwise, thus closing the surgically produced open bite. Counterclockwise rotation of the mandible afforded significantly greater sagittal displacement at the B point (mean 17 mm) than at the first molar (mean 10 mm) and produced adequate degrees of projection of the lower face when accompanied by a modest sliding genioplasty (mean 6.9 mm). Total advancement at the pogonion was a mean of 25.2 mm. In addition, posterior facial height was preserved, and mandibular and occlusal planes were normalized to mean angles of 27 and 10 degrees, respectively. At follow-up, which ranged from 9 to 24 months with a mean of 14.1 months, the mean sagittal relapse at the B point was 1.9 mm. Although heretofore considered unstable and therefore not clinically accepted, maxillomandibular counterclockwise rotation to normalize the occlusal plane rotational deformity provides stable, aesthetically superior results in patients with extreme degrees of mandibular micrognathia. Extended follow-up will be necessary to document long-term stability.

Adolescent↗

PubMed1992

Facial skeletal expansion: treatment strategies and rationale.

Forty-three nonconsecutive patients presenting with dentofacial deformity underwent surgical procedures designed intentionally to create skeletal disproportion in the sagittal and/or vertical dimensions. This was accomplished through expansion (enlargement) of the facial skeleton beyond normative standards. At the time of follow-up, which ranged from 14 to 36 months (mean 18.4 months), soft-tissue cephalometric analyses documented facial disproportion to exist in 37 of the 43 patients treated. Thirty-two patients had excessive anterior divergence (facial protrusion) at pogonion, and 17 patients had excessive lower face height as measured from subnasale to menton. All patients were judged to have had a favorable aesthetic outcome. This philosophy of facial skeletal expansion is predicated on two concepts: The first of these is that facial proportions and dimensions beyond those which are considered normal may be extremely attractive in a given individual. Second, the soft-tissue response to skeletal expansion is more favorable and predictable than it is to skeletal contraction in providing for well-supported soft tissues. This treatment planning approach is based on the dynamic interrelationship between the skeletal foundation and the soft-tissue facial mask. It relies on physical examination as the major determinant of aesthetic surgical options.

Adolescent↗

PubMed1991

Porous block hydroxyapatite in orthognathic surgery.

Seventy-six nonconsecutive patients undergoing orthognathic surgery, in whom blocks of porous hydroxyapatite were implanted into osteotomy gaps in lieu of autogenous bone grafts, are the subjects of this report. Surgical procedures include inferior maxillary repositioning (10 patients), maxillary advancement (24 patients), transverse maxillary expansions (17 patients) and inferior repositioning of the chin (25 patients). A total of 140 anatomic sites were implanted. Eleven patients later consented to open biopsy of the implant material at a mean 10.2 months following implantation. At the time of follow-up, mean 16.3 months, excellent osseous stability was observed. Three patients developed complications relative to the presence of the implant. Twenty-one of 24 biopsy specimens demonstrated an osseous union of implant to bone with osseous deposition within the implant pores. Radiographic follow-up revealed implant blocks to maintain their volume with no change in density or discreteness. The biological behavior and biomechanical properties of porous block hydroxyapatite are discussed. These implant characteristics make it a feasible bone graft substitute in orthognathic surgery and justify its continued use in this context.

Adolescent↗

PubMed1991

Maxillary advancement for mandibular prognathism: indications and rationale.

The surgical correction of mandibular prognathism has traditionally involved posterior repositioning of the mandibular body. This treatment approach corrects the skeletal disproportion at the expense of reducing facial skeletal volume and can unpredictably result in inadequately supported soft tissues with loss of skeletal definition. In an effort to avoid these sequelae of mandibular reduction, 18 patients diagnosed as having mandibular prognathism were treated with maxillary advancement surgery at the Le Fort I level. Mean patient SNB angle was 85.2 degrees, as compared with a normal 79 +/- 3 degrees. Maxillae were documented to be in normal position relative to both cranial base and Frankfort horizontal. The mean maxillary advancement was 6.9 mm, with a range of 4.5 to 8.8 mm. All patients required genioplasty to reduce vertical chin height and/or to laterally shift the chin. At the time of follow-up (mean 16.2 months), all patients retained cephalometric data suggestive of enlarged mandibles and excessive anterior facial divergence. However, maxillomandibular harmony and facial convexity had been restored without sacrificing skeletal volume. Treatment results demonstrated these faces to be skeletally well proportioned despite lower face protrusion that was beyond "normal." Postoperative appearances were characterized by a well-supported soft-tissue envelope and a highlighted skeletal foundation, creating angular, well-defined lower faces. These findings support the credibility of maxillary advancement as the procedure of choice in selected individuals with mandibular prognathism. Indications and an aesthetic rationale for this surgical approach are presented.

Adolescent↗

PubMed1991

Aesthetic refinements in genioplasty: the role of the labiomental fold.

The vast majority of patients requesting aesthetic enlargement of their chins have a class II skeletal deformity secondary to a small mandible. Class II skeletal patterns are frequently associated with abnormalities of lower face height, which, in turn, affect labiomental fold morphology. Of 68 patients who were to undergo sagittal advancement of their chins, 88 percent were considered to have abnormal labiomental fold morphology that was closely related to abnormalities of the facial height. Patients with decreased lower face height (40 percent) had exaggerated, deepened folds with acutely closed angles between the lower lip and chin pad, whereas those with increased lower face height (25 percent) had shallow, effaced folds. Patients with normal lower face height had variable fold morphology. Isolated sagittal advancement and/or simultaneous advancement and vertical shortening deepened the labiomental fold and closed the angle between the chin pad and lower lip. Simultaneous advancement and lengthening tended to deemphasize the fold, making it appear less deep in 20 of 34 patients, or at least mitigated further accentuation of the fold in 14 of 34 patients. Altered labiomental morphology and its relationship to the class II skeletal deformity is discussed. Treatment planning decisions are suggested, taking into account labiomental aesthetics and how they are influenced by advancement genioplasty.

Adult↗

PubMed1991

The response of porous hydroxyapatite to contiguous tissue infection.

Two patients are presented in whom severe clinical infection developed in tissue adjacent to and contiguous with previously implanted blocks of porous hydroxyapatite. Both infections resolved with appropriate antibiotics, debridement, and drainage of infected tissues. Hydroxyapatite blocks were left in situ. This unusually favorable response of an alloplast to infection is attributable to the abundant vascular supply of this porous implant. Although reliable dogma can hardly be concluded from two clinical examples, these experiences suggest that once ingrown, porous hydroxyapatite does not behave in a fashion that is typical of foreign bodies in the midst of infection. For the first time, clinical evidence has been offered to support the experimental data that vascularized hydroxyapatite has the ability to resist infection.

Adolescent↗

PubMed1991

When osteotomies should be considered.

Osteotomy at various levels of the facial skeleton is entirely justified in selected aesthetic surgical patients. By the very nature of aesthetic surgery, the morbidity potential associated with such osteotomies must be extremely low. Accordingly, osteotomy at the symphyseal level and the LeFort I level are the most commonly performed procedures in the aesthetic surgical patient. Aesthetic changes required in the vertical plane of space will require osteotomy, because these cannot be reliably and consistently achieved through changes in skeletal surface contour. Lastly, when the extent of change required is greater than what can be naturally achieved with surface augmentation, osteotomy must be considered. This last indication is frequently found in the aesthetic surgical patient presenting with a facial skeletal imbalance that has been previously treated with orthodontics to correct a skeletally based malocclusion. Recent technical advances have markedly reduced the associated morbidity of facial osteotomies and, therefore, have made this treatment option more acceptable to aesthetic surgical patients. Ceramic orthodontic brackets and surgical hooks and lingual orthodontic appliances have made presurgical orthodontic preparation more aesthetic and socially acceptable for LeFort I osteotomy patients. The use of rigid fixation, obviating the need for any postoperative intermaxillary fixation, has also made this treatment approach more appealing to aesthetic patients. Lastly, the efficacy of nonresorbable bone substitutes--in particular, porous, block hydroxyapatite--has, to a significant extent, obviated the need for harvesting autogenous bone grafts, further reducing surgical morbidity.

Face↗

PubMed1990

Lactation as a complication of aesthetic breast surgery successfully treated with bromocriptine.

A case is presented of lactation occurring ten days after mastopexy with augmentation mammaplasty. Milk-draining sinuses involving the operative incisions necessitated prompt diagnosis and treatment to avoid breast implant loss. Bromocriptine, an ergot derivative, was used to suppress a pathologically elevated prolactin level and successfully effect a rapid resolution of lactation.

Adult↗

PubMed1990

The biologic behavior of hydroxyapatite implanted into the maxillofacial skeleton.

Eleven patients who previously had undergone elective facial osteotomy and in whom blocks of porous hydroxyapatite were implanted into osteotomy gaps later consented to open biopsy of the implant material. A total of 24 biopsies were harvested at a mean time of 10.2 months following implantation. Gross anatomic findings were recorded at the time of biopsy. Specimens were harvested from the zygomatic buttress of the maxilla (12), the piriform buttress of the maxilla (4), the maxillary interdental premolar region (2), and the anterior mandible (6). Histologic sections were examined undecalcified using a modified trichrome stain. Eight of the 11 patients were followed radiographically for a minimum of 24 months. In the absence of infection, there was rapid fibrovascular ingrowth and, provided there was contact with host bone, bone ingrowth. This was observed in 21 of 24 biopsy specimens. The extent of bone ingrowth, as judged qualitatively, was highly variable and did not correlate with the time interval from implantation, anatomic site, or surface area of bone-implant interface. A healing process involving an osteoid phase of bone maturation and suggestive of continued net bone production was consistently found. The gross anatomic, radiographic, and histologic findings are discussed and provide further insight into the biologic behavior of porous block hydroxyapatite implanted into the maxillofacial skeleton.

Adolescent↗

PubMed1990

Definitive surgical correction of vertical maxillary deficiency.

Inferior repositioning of the maxilla to correct vertical maxillary deficiency has been associated with variable degrees of instability and subsequent relapse. Resorption of bone-graft material has been incriminated as the primary cause of postoperative instability. This paper reports on nine patients who have undergone inferior maxillary repositioning resulting in no residual bone contact between the down-fractured maxilla and superior midface. Mean inferior maxillary repositioning was 6.2 mm. Osteotomy gaps were implanted with porous block hydroxyapatite (Interpore 200), and maxillae were rigidly fixed in position with miniplates. No postoperative intermaxillary fixation was utilized in any patient. Follow-up ranged from 11 to 28 months, with a mean of 19.6 months. Cephalometric analyses at follow-up revealed excellent stability of the repositioned maxillae, with a mean vertical relapse of 4.3 percent. No complications were associated with this procedure. The biomechanical rationale contributing to the success of this operative technique is discussed.

Adolescent↗

PubMed1989

Porous, block hydroxyapatite as an interpositional bone graft substitute in orthognathic surgery.

Forty-six nonconsecutive patients undergoing orthognathic surgery in whom blocks of coralline, porous hydroxyapatite (Interpore-200) were used in lieu of interpositional bone grafts are the subjects of this report. Surgical procedures included inferior repositioning of the maxilla (7) and chin (12), maxillary advancements in cleft (4) and noncleft individuals (13), and transverse maxillary expansions (12). Patients included in this study were only those in whom bone grafts would have been harvested had hydroxyapatite not been available. A total of 93 anatomic sites were implanted. The complication rate attributable to the use of the implant was 4.3 percent. Follow-up period ranged from 6 to 20 months, with a mean of 9.3 months. At this time, osseous stability was confirmed cephalometrically in all but two patients undergoing maxillary expansions. The biologic behavior and mechanical properties of coralline-derived, porous, block hydroxyapatite are discussed. These implant characteristics make it a feasible bone graft substitute for interpositional use in orthognathic surgery. Proper indications for its use as well as technical details to minimize complications are stressed.

Adolescent↗

PubMed1989

Segmental osteotomies of the maxilla.

Multiple segment Le Fort I osteotomies provide the maxillofacial surgeon with the capabilities to treat complex dentofacial deformities existing in all three planes of space. Sagittal, vertical, and transverse maxillomandibular discrepancies as well as three-dimensional abnormalities within the maxillary arch can be corrected simultaneously. Accordingly, optimal aesthetic enhancement of the facial skeleton and a functional, healthy occlusion can be realized. What may be perceived as elaborate treatment plans are in reality conservative in terms of osseous stability and treatment time required. The close cooperation of an orthodontist well-versed in segmental orthodontics and orthognathic surgery is critical to the success of such surgery. With close attention to surgical detail, the complication rate inherent in such surgery can be minimized and the treatment goals achieved in a timely and predictable fashion.

Adult↗

PubMed1988

Lip-nasal aesthetics following Le Fort I osteotomy.

Forty-one patients undergoing Le Fort I osteotomy for superior and/or anterior repositioning of the maxilla were prospectively studied for changes in soft-tissue morphology of the nasomaxillary region. Nasal parameters studied were changes in interalar rim width and nasal tip projection. It was observed that alar rim width increases with anterior and/or superior repositioning of the maxilla, but increases in nasal tip projection occur only when there is an anterior vector of maxillary movement. These nasal changes could not be quantitatively correlated to magnitude of maxillary movement. Lip changes studied were the horizontal displacement at the vermilion border and subnasale versus that of the incisal edge and point A, respectively, when the maxilla is sagittally advanced and the vertical shortening of the lip versus that of the incisal edge when the maxilla is shortened. Using linear regression analysis, horizontal displacement of the upper lip at the vermilion border was 0.82 +/- 0.13 mm for every 1 mm of maxillary advancement at the incisal edge (p less than 0.001) and 0.51 +/- 0.13 at the subnasale for every 1 mm of maxillary advancement at point A (p less than 0.001). Eighty percent of patients undergoing maxillary intrusive procedures had lip shortening ranging from 20 to 50 percent of the vertical maxillary reduction. Surprisingly, no statistically significant correlation could be demonstrated for lip shortening versus extent of vertical maxillary reduction. Previous literature in disagreement with these findings is discussed. Guidelines for treatment planning utilizing these data are suggested.

Adolescent↗

PubMed1988

Surgical correction of the vertically deficient chin.

Surgical correction of the vertically deficient chin has received relatively little attention. This paucity of information is most likely related to the failure to diagnose vertical microgenia and the questionable stability of its surgical correction utilizing autogenous bone grafts. This paper reports on eight patients who have undergone vertical augmentation genioplasty utilizing a transverse symphyseal osteotomy and interpositional implantation of porous, block hydroxyapatite. All patients had preoperative measured decreases in lower face height. Mean vertical lengthening of the chin was 5.3 mm. Seven of the eight patients had class II occlusions and underwent simultaneous sagittal advancement of the chin. Follow-up at a mean time of 11.1 months revealed complete stability of the vertically repositioned symphyseal segment. Mean ratio of the vertical soft to hard tissue augmentation was 0.89:1. There were no instances of operative complications. Vertical facial aesthetics and their application in the evaluation and treatment of patients with vertically deficient lower faces and chins are reviewed.

Adult↗

PubMed1987

Spontaneous subdural hygromas: a complication following craniofacial surgery.

We present a case report of symptomatic, spontaneous subdural hygromas complicating craniofacial resection of a malignant skull base tumor. This complication occurs after prolonged spinal drainage instituted to prevent cerebrospinal fluid fistulas secondary to insecure dural repair. We believe that this complication may be seen repeatedly as indications for craniofacial surgery in the elderly continue to expand.

Aged↗

PubMed1987

Delayed microcirculatory hyperpermeability following perfusion washout.

Recent experimental data have demonstrated improved flap survival following perfusion washout with a synthetic, chemically defined, mammalian plasma. In an effort to define the physiology responsible for the efficacy of perfusion, the method of "labeling" hyperpermeable blood vessels with Monastral blue B in rat epigastric vascular island flaps was utilized. Results confirmed that capillary and venular hyperpermeability is an early and progressive pathophysiologic event in ischemic flap tissue and one which is reversible prior to a critical ischemic period. Perfusion washout with a physiologic, acellular plasma substitute delays the onset of vascular hyperpermeability. This may be a mechanism responsible for improving tissue survival following extended periods of warm ischemia (12 hours). It is implied that stagnant blood and products of hemolysis in the microcirculation may be detrimental to the functional and anatomic integrity of the endothelial wall.

Animals↗

PubMed1987

The role of perfusion washout in limb revascularization procedures.

Amputated rat hindlimbs were subjected to either normothermic (26 degrees C) or hypothermic (4 degrees C) ischemia. Experimental limbs had their microcirculation washed out (either before or after the ischemic insult) with a physiologic acellular plasma substitute previously reported to enhance flap survival following extended periods of warm ischemia. Control limbs were not washed out; i.e., stagnant blood remained in these limbs. Following the ischemic interval, amputated limbs were replanted. Monastral blue B, a colloidal pigment capable of labeling leaky blood vessels, was administered systemically to all rats just prior to vascular declamping. Limb biopsies of skin and muscle were harvested 30 minutes following revascularization in order to assess Monastral labeling and, therefore, the functional integrity of the microcirculation. Results confirm that stagnant blood under conditions of warm ischemia is detrimental to the functionality of the microcirculation in both skin (p less than 0.03) and muscle (p less than 0.007). Accordingly, perfusion washout, when performed prior to the ischemic period, enhances limb survival following 6 hours of warm ischemia (p less than 0.01). Hypothermia protects against the detrimental effects of stagnant blood; perfusion offers no benefit if hypothermic conditions prevail. Physiologic mechanisms responsible for these findings are discussed.

Animals↗