Function of the nasal muscles in normal subjects assessed by dynamic MRI and EMG: its relevance to rhinoplasty surgery

Myomodulation Using Botulinum Toxin in Septorhinoplasty for Crooked Noses: Introducing the Concept and Application of Nasal Muscle Imbalance Theory

The role of septorhinoplasty for adequate correction of deviated nose is well documented, but the rationales and patterns for recurrences after proper rhinoplasty remain unclear. There has also been little attention given to the influence of nasal musculatures on the stability of nasal structures after septorhinoplasty. The aim of this article is to propose our nasal muscle imbalance theory, which may explain the potential reason for redeviation of the noses in the initial period after septorhinoplasty. We postulate that in a chronically deviated nose, the nasal muscles on the convex side will be stretched and develop hypertrophy after prolonged period of increased contractile activity. On the contrary, the nasal muscles on the concave side will undergo atrophy due to reduced load requirement. In the initial period of recovery after a septorhinoplasty to bring the nose back to midline, this muscle imbalance is still uncorrected with unequal pulling forces on the nasal structure because the stronger nasal muscles on the previously convex side is still hypertrophied and exert stronger forces compared with the previously concave side, therefore increasing the risk of redeviation of the nose back to the preoperative side until muscle atrophy occurs in the convex side and a balanced nasal muscle pull is achieved. We believe that postseptorhinoplasty botulinum toxin injections can be used as an adjunct in rhinoplasty surgery to effectively block the pulling actions of the stronger or overacting nasal muscles by speeding up the atrophy process while allowing patient's nose to heal and stabilize in the desired position. However, further studies to objectively confirm this hypothesis is required, which include comparing topographic measurements, imaging and electromyography signals before and after injections in postseptorhinoplasty patients. The authors have already planned a multicenter study to further evaluate this theory.

Evaluation of diagnostic accuracy of cone beam computed tomography and multi-detector computed tomography for detection of anatomical variations in rhinoplasty

BACKGROUND

Different imaging techniques, such as multi-detector computed tomography (MDCT) scan and cone beam computed tomography(CBCT), are used to check the structure of the nose before rhinoplasty. This study aimed to evaluate the accuracy of two imaging techniques, MDCT scan, and CBCT, in diagnosing structural Variations in rhinoplasty for the first time.

METHODS

This diagnostic accuracy study was conducted on 64 rhinoplasty candidates who complained of snoring and sleep apnea or had a positive result in the examination with Cottle's maneuver or modified Cottle technique between February 2021 and October 2022 at 15- Khordad Hospital affiliated to Beheshti University of Medical Sciences. Before rhinoplasty, patients were randomly assigned to one of the CT and CBCT techniques with an equal ratio. Scans were assessed for the presence of Nasal septum deviation (NSD), Mucocele, Concha bullosa, and nasal septal spur by two independent radiologists. The findings of the two methods were evaluated with the results during rhinoplasty as the gold standard.

RESULTS

NSD was the most common anatomical variation based on both imaging techniques. The accuracy of CBCT for diagnosing Nasal Septum Deviation and Mucocele was 80% and 75%, respectively. The sensitivity, specificity, and accuracy of CBCT in detecting Concha bullosa were 81.3% and 83.3%, respectively. The Kappa coefficient between CBCT and intraoperative findings for diagnosing NSD and Concha Bullosa was 0.76 and 0.73, respectively (p < 0.05).

CONCLUSION

CBCT can be considered a suitable method with high accuracy and quality to evaluate the anatomical variations before rhinoplasty.

Crossing fibers may underlie the dynamic pulling forces of muscles that attach to cartilage at the tip of the nose

The present study used microdissection, histology, and microcomputed tomography (micro-CT) with the aims of determining the prevalence and patterns of the depressor septi nasi (DSN) and orbicularis oris (OOr) muscles attached to the footplate of the medial crus (fMC) of the major alar cartilage, focusing on their crossing fibers. The DSN and OOr attached to the fMC of the major alar cartilage were investigated in 76 samples from 38 embalmed Korean adult cadavers (20 males, 18 females; mean age 70 years). The DSN, OOr, or both were attached to the fMC. When the DSN ran unilaterally or was absent, some OOr fibers ascended to attach to the fMC instead of the DSN in 20.6% of the samples. Crossing fibers of the DSN or OOr attached to the fMC were found in 82.4% of the samples. Bilateral and unilateral crossing fibers were found in 32.4% and 50.0%, respectively, and no crossing fibers were found in 17.6%. The DSN and OOr that attached to the fMC could be categorized into six types according to presence of the DSN and the crossing patterns of the DSN and OOr. Anatomical findings of the DSN and OOr that attached to the fMC were confirmed in histology and micro-CT images. These findings offer insights on anatomical mechanisms that may underlie the dynamic pulling forces generated by muscles that attach to the fMCs and on evolutionary variation observed in human facial expressions. They can also provide useful information for guiding rhinoplasty of the nasal tip.

A Single-Blinded Prospective Study on Using Botulinum Toxin Type A for Reducing Alar Mobility

BACKGROUND

With widespread utilization of instant social media, people desire a minimally invasive treatment to improve alar dynamic aesthetic, but few practical procedures on reducing alar mobility have been conducted.

OBJECTIVES

This study aimed to verify the effects of botulinum toxin on reducing nasal alar mobility and provide a supplemental treatment of rhinoplasty.

METHODS

This single-blind prospective study included a cohort of 20 participants with the desire to improve their alar dynamic aesthetic. The experimental group was injected with 3U botulinum toxin type A at dilator naris anterior, dilator naris vestibularis, levator labii superioris alaeque nasi, and dilator naris, and the control group received the equivalent of saline. Standardized facial movement (from rest to maximum smile without revealing teeth) was recorded with a 3-dimensional imaging system. The changes between rest and maximum smile statuses represented alar mobility and were generated by MOBILITY=WIDTHsmile-WIDTHrestWIDTHrest×100 % . Alar mobility and root mean square analysis were employed for postoperative evaluations.

RESULTS

In the experimental group, alar flaring mobility decreased from 10.05% ± 6.40% to 4.91% ± 3.48%(P < 0.05), and alar base mobility decreased from 16.83% ± 5.69% to 12.50% ± 4.89% (P < 0.05), whereas no significant changes in alar mobility were found in the control group. In root mean square analysis, changes in the experimental group were significantly higher than in the control group (P < 0.05).

CONCLUSIONS

Botulinum toxin type A can effectively restrain alar mobility without any significant adverse events and improve alar dynamic esthetic, which can serve as a minimally invasive method or supplemental treatment for rhinoplasty.

LEVEL OF EVIDENCE: 2

A Novel Study on Alar Mobility of HAN Female by 3dMD Dynamic Surface Imaging System

AIM

The aim of this study is to conduct a quantitative analysis on alar mobility of HAN females and provided referenced materials for alar dynamic aesthetic.

METHODS

One hundred and fifty healthy HAN females without rhinoplasty, nasal injury, nasal deformity and craniofacial deformity were included in this study. 3dMD surface imaging system was used for anthropometric analysis. All participants were instructed to perform the desired dynamic facial expression from rest to maximum smile without reveling teeth and recorded by 3dMD dynamic surface imaging system simultaneously. Two frames of rest status and alar maximum enlargement were selected for measuring alar width, alar base width and inner-canthal distance. The difference between two status represented alar mobility, which was generated through equation: [Formula: see text].

RESULTS

Alar mobility consisted of alar flaring mobility and alar base mobility. The alar flaring mobility was (9.49 ± 4.90)%, reference range was(1.45, 17.53)% and regression equation between rest and maximum smile was Y = 7.953 + 0.886X (R² = 0.641, p = 0.000); the alar base mobility was (17.94 ± 10.44)%, reference range was (0.88, 35.00)% and regression equation between rest and maximum smile was Y = 4.481 + 0.966X (R² = 0.528, p = 0.000.

CONCLUSION

Asian alar anatomy has great distinction from Caucasian, processing conspicuous alar movement and damaging alar aesthetic dynamically. This study novelly defined alar mobility by three-dimensional anthropometric analysis, providing objective references for alar dynamic aesthetic and arousing plastic surgeons' attention on keeping balance of static and dynamic aesthetic in rhinoplasty.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effect of two fascial incision options for access to the temporomandibular joint on facial nerve function: objective investigation

This study was performed to compare the effects on facial nerve (FN) function of the deep supra-temporalis muscle subfascial approach (DSFA) and traditional fascial approach (TFA) for access to the temporomandibular joint (TMJ), via qualitative and quantitative evaluations. Thirty patients requiring open TMJ surgery were randomly allocated to one of two groups: group A patients underwent the DSFA approach, while group B patients underwent the TFA approach. The TMJ was accessed via modified endaural incision with temporal extension. Clinical examinations, FN conduction tests, and electromyography (EMG) of the frontalis and orbicularis oculi muscles were used to assess FN function. A FN function deficit was noted in 50% of the whole sample population immediately after surgery, with no statistically significant difference between the groups (P = 0.082). Overall, 37.5% of the total study population experienced temporary loss of frontalis muscle activity, while zygomatic nerve injury was seen only in 25% of group A. Within 2-6 months, normal function returned in both groups. Nerve conduction studies showed no statistically significant difference between the groups in terms of nerve amplitude or latency after surgery. However, EMG of orbicularis oculi activity showed a significant difference between the groups after 6 months (P = 0.010). The results suggest that the traditional dissection approach is more protective of the FN, especially the zygomatic branch, than the deeper dissection technique.

Rhinoplasty for Hypertrophied Transverse Nasalis Muscle: A Case Report

Negatively impacting the aesthetics of the face, nasal deformities can be attributed to many congenital or acquired causes, of which muscular hypertrophy is uncustomary. In this article, we narrate a case of a 26-year-old woman with a prominently wide mid-vault, in addition to other abnormalities of the nose. It was thought to originate from soft tissue because it was thick and firm to palpation. Open rhinoplasty was done where hypertrophy of the paired transverse nasalis muscle was observed and resected. The patient enjoyed a safe postoperative period with excellent cosmetic results and minimal effect on the nasal function in terms of breathing and pronunciation. We recommend this approach to any patient with a similar disfigurement due to its simplicity and ability to correct other co-existing nasal disfigurements.

Conventional Resection Versus Preservation of the Nasal Dorsum and Ligaments: An Anatomic Perspective and Review of the Literature

Preservation rhinoplasty may refer to preserving several anatomic components including: the nasal bones, upper lateral cartilages, the keystone area and/or ligaments of the nose. Preserving the osseocartilaginous framework or "dorsal preservation" minimizes or completely avoids violation of the dorsal aesthetic lines' architecture. Conventional hump reduction in open rhinoplasty disrupts these lines; however, it also provides versatility to reshape the entire dorsum. Surgical success with either technique requires a thorough understanding of the underlying nasal anatomy.

The Role of the Depressor Nasi Septi Muscle in Nasal Air Flow

Background

Musculus depressor septi nasi and its tendon, the dermocartilaginous ligament, play an important role in external nasal valve and nasal respiration. If the ligament is cut during septorhinoplasty operations, nasal functions of the nose and facial expressions are affected. Therefore, the aim of this study was to investigate the role of M. depressor septi nasi in nasal respiration at open rhinoplasty operations using rhinomanometry and electromyography.

Methods

The study included 29 patients who had only external nasal deformity (nasal hump deformity). All patients underwent open rhinoplasty. The dermocartilaginous ligament of the patients in the study group (DCL + group) was repaired but not in the control group (DCL − group). Rhinomanometry and electromyography were applied to all patients preoperatively and postoperatively.

Results

In the DCL − group, right and left nasal airflow values were significantly lower in post-op (562.92 cm³/s and 548.57 cm³/s), whereas right, left, and total nasal resistances were significantly lower in pre-op (0.28 Pa/cm³/s, 0.22 Pa/cm³/s, and 0.11 Pa/cm³/s). Statistically significant differences were not found between rhinomanometric measurements in pre-op and post-op values of the DCL + group. Post-op right, left and mean values of M. depressor septi nasi amplitude in the DCL + group (2.05 mV, 2.0 mV, 2.02 mV) were significantly higher than those in the DCL − group (1.52 mV, 1.61 mV, 1.57 mV).

Conclusion

Repair of the dermocartilaginous ligament during open rhinoplasty operations enhances nasal respiratory functions by expanding the external nasal valve through M. depressor septi nasi and allows the nose to participate in mimic movements.

Level of Evidence IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Electronic supplementary material

The online version of this article (10.1007/s00266-020-01693-3) contains supplementary material, which is available to authorized users.

Effects of the Nasal Muscles on the Nasal Airway

Background

The nasal muscles and their function are not clearly defined. The nasal muscles generally are thought to act synergistically to produce mimetic motion and affect the nasal airway. We proposed direct examination of the effects of the nasal muscles on the nasal airway.

Methods

Rhinomanometry was performed on volunteers. After paralysis of the nasal muscles with lidocaine, rhinomanometry was performed again to measure nasal airway function with the patient at rest and attempting to flare his/her nostrils. Each patient's rhinomanometric results (at rest and attempting to flare the nostrils) taken before injection of lidocaine served as the control for comparison of his/her results postinjection. The structural tension of the ala at rest and with active flaring of the nostril was measured also, and the results pre- and postparalysis with lidocaine were compared.

Results

The data from both the stiffness (structural tension) and the airflow portions, taken together, support the following conclusions. First, the paralysis was significant, although not complete. Clinical and stiffness data supported complete paralysis. Airflow data, which we think most sensitive, support a statistically significant affect of the injection, although incomplete paralysis.

Conclusion

All of the evidence supports an important role for the nasal muscles when actively used to increase nasal airflow. Second, the majority of the evidence supports an important resting nasal muscle tension that opens the nasal airway.

Ultrasonographic evaluation of long-term results of nasal tip defatting in rhinoplasty cases

OBJECTIVES/HYPOTHESIS

Nasal skin thickness has an important role in aesthetic results of rhinoplasty. The aim of this study was to evaluate the long-term results of tip and supratip skin defatting technique in rhinoplasty subjects using ultrasonography.

STUDY DESIGN

Prospective, randomized, case-control study.

METHODS

Among 111 rhinoplasty cases referred to a university hospital between February 2010 and September 2011, after physical examination and measuring the nasal tip and supratip skin thickness by ultrasonography, a total of 55 patients with thick and moderate skin were randomly allocated for rhinoplasty using one of the following methods: rhinoplasty with (case group) and without (control group) defatting tip and supratip skin. Ultrasonographic evaluation of the skins was repeated 1 and 12 months after surgery, and the data were analyzed by Wilcoxon and repeated measure tests using SPSS 17 software.

RESULTS

Twenty-eight of 55 candidates (10 men, 45 women; mean age, 25.1 ± 7.6 years) underwent skin defatting during rhinoplasty; the other 27 patients did not undergo this procedure. Forty-four patients completed the study. Thickness of tip and supratip skin was not statistically different before surgery and during follow-up evaluations in defatting and nondefatting technique groups (P = .7).

CONCLUSIONS

Defatting techniques have no effect on reducing tip and supratip skin thickness after rhinoplasty in moderate to thick skins.

Applied surgical anatomy of the nose

Although anatomy often seems static, the continual innovation of new surgical techniques and approaches, in reality, make it a dynamic field. The first essential principal of any surgery is the comprehensive knowledge of the anatomic area and its physiology. This assertion is especially true in functional and or cosmetic nasal surgery.

Reverse nasal SMAS-perichondrium flap to avoid supratip deformity in rhinoplasty

BACKGROUND

Supratip deformity is an iatrogenic convexity that occurs cephalically to the nasal tip. This is also known as "parrot beak" deformity and causes an unnatural appearance of the nose. In the literature there are several explanations of the mechanism of the deformity and methods to correct it. One of the most accepted theories about the cause of supratip deformity is overresection of the caudal dorsum. Healing soft tissues fill in the gap created between the septum and the tip of the lower lateral cartilages, leading to fullness in the supratip area. The lower third and basically distal third of the middle third of the nose include several muscle groups, ligamentous structures, and perichondrium as the subcutaneous soft tissues.

METHODS

With the idea of elevating a reverse-based flap basically from the lower third and the lower third of the middle third of the nose, including the perichondrium and SMAS tissue, we aimed to reduce this gap, which has the potential to accumulate soft tissues that cause supratip fullness. Between December 2008 and July 2010, the reverse nasal SMAS-perichondrium flap was used in 42 primary rhinoplasty patients.

RESULTS

This flap was used in 42 patients. Follow-up ranged from 3 to 18 months. No early or late complications were noted, such as infection, excessive bleeding, or extended edema. Minor revisions were performed in only two patients with the aim of achieving a smoother nasal dorsum.

CONCLUSIONS

The reverse nasal SMAS-perichondrium flap is a new flap. The results presented here are not long term; however, the preliminary results are promising. The flap should be avoided in cases of thin skin, or at least be used with caution, whereas in thick skin cases it is very safe. Further studies in larger groups are required to better define the advantages and disadvantages of this flap.

Evaluation of nasal airway alterations associated with septorhinoplasty by both objective and subjective methods

The aim of functional septorhinoplasty is to create an esthetically elegant nose and harmony in the face by preserving nasal function as well as maintaining or restoring adequate airway. Since nasal complaints are usually subjective, it may be difficult to evaluate the functions objectively. In the present study, we aimed to investigate the alterations in nasal function associated with septorhinoplasty by using both objective and subjective methods. The study population consisted of 40 patients who underwent septorhinoplasty and 40 healthy controls. Before and after the operation, visual analog scale, acoustic rhinometry, rhinomanometry, and Odiosoft-Rhino test were applied to all patients and controls. There were significant differences in all parameters both before and after the operation. While a significant difference was obtained between the patient and control groups in terms of preoperative values, no significant difference was found between postoperative values of these groups. Both objective and subjective methods are important in evaluations.

Electromyographic and electroneurographic changes in internal nasal muscles after endonasal and external rhinoplasty

BACKGROUND

Anatomical structures of the nose (including muscles) are elevated, sutured, or reshaped during rhinoplasty. Electromyography and electroneurography are the objective electrophysiologic tests performed for the direct measurement of nasal muscle function.

OBJECTIVES

The authors investigate the predictive values and functional status of nasal muscles during voluntary facial and nasal movements following open and closed rhinoplasty.

METHODS

In 48 patients who underwent rhinoplasty, surface electrodes were placed to preoperatively and postoperatively measure nasal muscle function with electromyography and electroneurography. Results were analyzed according to whether the patient had undergone open or closed rhinoplasty.

RESULTS

Electroneurography amplitudes were decreased postoperatively on both sides, in both groups. This increase was statistically significant (p < .001). Electromyography-recorded amplitude of nasal muscle contraction tension significantly decreased postoperatively in response to all voluntary movements in two cases in the closed rhinoplasty group (6.6%) and in two cases in the open rhinoplasty group (11.1%). In essence, the activity strength of the nasal muscles decreased postoperatively for some patients. The mean differences between the two groups were not statistically significant (p = .280).

CONCLUSIONS

The data showed no meaningful difference in injury to the nasal muscular layer between open and closed rhinoplasty.

New anatomical profile of the nasal musculature: dilator naris vestibularis, dilator naris anterior, and alar part of the nasalis

The aim of this study was to clarify the morphology and topography of the dilator naris vestibularis, dilator naris anterior, and alar part of the nasalis. Anatomical variations in the topographic relationships are also described to provide critical data for understanding nasal muscular functions. Anatomical and histological examinations were performed on 40 specimens of embalmed Korean adult cadavers. The dilator naris vestibularis muscle (named by the present authors) was located between the external and vestibular skin of the alar lobule. The muscle fibers radiated along the dome-shaped nasal vestibule. The dilator naris anterior muscle originated from the frontal surfaces of the lateral half of the lateral crus and the accessory alar cartilage adjacent to the lateral crus. The extent of the lower insertion of the dilator naris anterior muscle was at the alar groove. The alar part of the nasalis originated with the transverse part of nasalis from the maxilla. It ascended to attach to the alar crease and the adjacent deep surface of external skin of the alar lobule. These findings may provide anatomical knowledge required to understand the structure and function of these nasal muscles such as during rhinoplasty or other surgery of the face.

New anatomical insight of the levator labii superioris alaeque nasi and the transverse part of the nasalis

PURPOSE

The aim of this study was to clarify the morphology and topography of the deep layer of levator labii superioris alaeque nasi muscle (LLSAN) and the transverse part of the nasalis. Anatomical variations in the topographic relationships were also described to understand the function of the LLSAN and the transverse part of the nasalis.

METHODS

Anatomical dissections were performed on 40 specimens of embalmed Korean adult cadavers.

RESULTS

The LLSAN was divided into two layers, which were superficial and deep in the levator labii superioris muscle (LLS), respectively. The superficial layer of LLSAN descended on the LLS, and the deep layer was located deep in the LLS. The deep layer of LLSAN originated from the superficial layer of LLSAN and the frontal process of the maxilla. It inserted between the levator anguli oris and the orbicularis oris muscles. This transverse part of the nasalis received some muscle fibers from the superficial layer of LLSAN in 90% (36/40) of specimens. The transverse part of the nasalis originated from the maxilla and ascended, passing posterior to the superficial layer of LLSAN in 65% (26/40) of specimens. However, it originated as two muscle bellies from the maxilla and the upper half of the alar facial crease, respectively, in 35% (14/40) of specimens.

CONCLUSIONS

These findings will be crucial data to understand the structure and function of the LLSAN and the transverse part of the nasalis.

Anatomy of the alar lobule in the Asian nose

OBJECTIVE

To provide details of the unique anatomical features on the alar lobule region in the Asian nose.

METHODS

We hypothesized that the shape of the alar lobule is dependent on its anatomy. The alar lobules were classified into flared type and straight type depending on their gross prominence and roundness. A total of 20 fresh cadaver noses (10 of each type) were dissected. Anatomical differences between the flared and straight types were investigated by gross and histologic studies.

RESULTS

The alar lobule consisted of three layers; external skin, muscle, and vestibular skin. The dilator naris anterior and dilator naris posterior muscles were well developed in the flared type alar lobules, whereas they were poorly developed in the straight type. The insertion of the dilator naris posterior muscle in the flared type was found to extend more anteriorly to the middle of alar lobule as well as to the alar base, whereas in the straight type the insertion was limited to the alar base only. External skin at the lateral end of the flared type was thicker than of the straight type. No significant differences were seen in other structures of the alar lobule region.

CONCLUSIONS

The gross appearance of the alar lobule is mainly affected by the volume of the dilator naris anterior muscle, the insertion of the dilator naris posterior muscle, and the thickness of the external skin at the lateral end of the alar circumference.

Factors affecting nostril shape in Asian noses

BACKGROUND

Because few studies have been performed regarding the factors affecting nostril shape in Asian noses, this study was undertaken to determine them.

METHODS

A total of 20 fresh cadaver noses were classified into horizontal and vertical types and dissected. The authors investigated the presence, volume, and insertions of muscles surrounding the ala; alar cartilage shape; footplate segment ratio of the medial crus; and the characteristics of tip supporting structures.

RESULTS

Horizontal nostril types had larger dilator naris anterior and posterior muscular components. In particular, the insertion of the dilator naris posterior muscle extended to the midpoint between the alar base and the nasal tip, whereas that of the vertical type was limited to the alar base. Insertion of the depressor septi nasi muscle was also more extensive in horizontally oriented nostrils. In terms of the shape of the lower lateral cartilage, the horizontal nostril type had a predominantly concave configuration of the lateral crus, whereas the vertical nostril type had the opposite concave configuration. A significant difference was also noted in the footplate segment ratio of the medial crus. However, no differences were observed in terms of the shape of the medial crus and the characteristics of the tip supporting structures.

CONCLUSIONS

Nostril shape is mainly affected by the volume of the dilator naris anterior and posterior muscle, the insertions of the dilator naris posterior and the depressor septi nasi muscle, the shape of the lateral crus, and the footplate segment ratio.

Cleft lip nose: a different approach

The aim of this study is to demonstrate a different manner of treating cleft lip nose by approaching the problem at its origin, the nasolabial gap. The surgical technique we propose corrects the affected structures from the "bottom to the top." First we have to make sure that the orbicularis oris is well oriented, then we have to create space for the twisted alar cartilage, and finally we reach the tip of the nose with less asymmetry to correct, compared with previously published data. Before attempting any additions of grafts, implants, etc. for the restoration of any congenital deformity, especially clefts, the surgical team must try to reposition, reorganize, and reorient the structures affected by a lack of continuity or a gap as a result of the embryogenesis.

Nose muscular dynamics: the tip trigonum

In 1995, the senior author (E.E.F.) published an article in which he described the musculus digastricus septi nasi labialis. In the article presented here, work carried out by anatomists and other researchers who, over the last two centuries, studied nose muscular dynamics is described. The present study is based on Gray's Anatomy, which, in 1858, first described the nasal tip muscles, along with the other nasal muscles. Later works not only used different terminology for these muscles but also ignored some, creating tremendous confusion. The study presented here provides an update of the exact terms, location, insertions, and muscle functions of the muscles of the nose. Each nose muscle is described with regard to the two portions able to produce separate contractions. In this study, the term "dual function" is used and characterizes the nasal mimetic muscles that do not have well-defined fascia. Therefore, there is doubt about the existence of a real nasal superficial muscle aponeurotic system. The musculus myrtiformis seems to have a dual function, inserting in the canine fosse and in the periosteum of the central incisors, forming two portions-one to the septum and the other to the nostril-each of which has specific functions. This study has been based on research in physiognomy, the science of expression. With regard to the basis for nose expressions, common anatomical research is excluded because it provides a different view of the dynamics studied to date. The term trigonum musculare apicis nasi defines the interaction of the musculi compressor narium minor and dilator naris anterior, connecting with the columellar bundle of the musculus digastricus and levering the nasal spine. This muscular trigone creates circular concentric and eccentric movements of the nasal tip.

Intrinsic nasal muscles and their electromyographic evaluation after external septorhinoplasty

OBJECTIVES

Rhinoplastic surgery is performed for the improvement in the appearance of the nose, but it should not cause any detrimental effect on the intrinsic muscles. This study was conducted to evaluate the influence of the external rhinoplasty on intrinsic nasal muscles.

METHODS

Twenty-one patients were operated on by external septorhinoplasty. Functions of the nasal muscles were assessed by electromyography in response to voluntary nasal movements in patients before and after surgery.

RESULTS

Postoperative electromyographic activities of the muscles were significantly less than preoperative measurements for all movements.

CONCLUSION

Influence of the surgical incisions, alterations of the sites of origin and/or insertion of the muscles, and the postoperative healing process can be incriminated for the decreased muscular activity. Nasal muscle function requires a better appreciation and respect for the achievement of the best aesthetic and functional results. The nasal valve reconstructive procedures should be applied routinely to compensate for this inevitable muscular involvement.

Novel technique for three-dimensional visualisation and quantification of deformable, moving soft-tissue body parts

BACKGROUND

Three-dimensional (3D) imaging of delicate, moving soft-tissue body parts is very difficult. Our understanding of the muscles that control lip movements is based largely on histological and cadaveric studies, which provide scant information about dynamic morphology. Our aim was to develop an innovative scanning technique for the imaging and reconstruction of dynamic orofacial morphology by use of 3D and four-dimensional (4D, ie, 3D plus time) ultrasonography.

METHODS

Four volunteers (including one patient) underwent ultrasonography with 3D/4D imaging systems. To avoid deformation of the delicate orofacial structures, a water bath with an acoustic window was devised. The orofacial part was immersed in the bath throughout scanning, and a timer was used to synchronize lip movements with the 4D scan.

FINDINGS

4D views showed the functional differences in superficial and deep muscle groups of the lips, and clearly showed the changes occurring with movement of the lips and mouth. In the patient, a pathological layer and its extension corresponding to surface malformation were clearly identified.

INTERPRETATION

We have developed a prototype device that has made possible 3D and 4D examination of orofacial anatomy and function. With further refinement of the device and improvement in 4D acquisition timing, this technique may offer a new way of dynamically imaging and quantifying many soft-tissue parts in 3D without deforming structure or disturbing function.