10.14639/0392-100X-N1598
Silent Sinus Syndrome (SSS) is a rare disease consisting of a collapse of maxillary sinus walls with concomitant orbital floor descent. Due to its rareness, the literature highlights some confusion on its definition, diagnosis and management. A PRISMA-compliant systematic review was performed on SSS with focus on definition, diagnosis and therapeutic management. Twenty-eight studies were selected, with 276 patients evaluated. The analysis revealed that the leading definition of SSS includes evidence of both enophtalmos and maxillary atelectasia. Although the definition of SSS accepts only spontaneous sinus collapse, the presence of sinonasal diseases and history of facial trauma are starting to be included in the criteria. Most studies (n = 21) considered CT scans satisfactory for diagnosis of SSS, while 7 also performed MR. The majority of SSS were successfully treated with isolated functional endoscopic sinus surgery (n = 17), sparing orbital reconstruction as a rescue procedure in case of non-satisfactory long-term resolution of signs. Although the literature is starting to coordinate on diagnosis of SSS, our review revealed the necessity of consensus on its definition and management.
text/xml
1827-675X
1598
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Carlotta Pipolo
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ACTA Otorhinolaryngologica Italica
silent sinus syndrome management
Silent sinus syndrome: systematic review and proposal of definition, diagnosis and management
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2022-06-30
2021-04-02
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1
Carlotta Pipolo
2022/06/30
10.14639/0392-100X-N1598
305
Department of Otorhinolaryngology, Santi Paolo e Carlo Hospital, Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
1827-675X
silent sinus syndrome management
316
Silent sinus syndrome: systematic review and proposal of definition, diagnosis and management
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ACTA OTORHINOLARYNGOLOGICA ITALICA 2022;42:305-316; doi: 10.14639/0392-100X-N1598




Review


Silent sinus syndrome: systematic review
and proposal of definition, diagnosis and management
Sindrome del seno silente: revisione sistematica e proposta di definizione, diagnosi
e trattamento
Cecilia Rosso1, Alberto Maria Saibene1, Giovanni Felisati2, Carlotta Pipolo2
1
 Department of Otorhinolaryngology, Santi Paolo e Carlo Hospital, Università degli Studi di Milano, Milan, Italy; 2 Department of
Otorhinolaryngology, Santi Paolo e Carlo Hospital, Department of Health Sciences, Università degli Studi di Milano, Milan, Italy


SUMMARY
Silent sinus syndrome (SSS) is a rare disease consisting of a collapse of maxillary sinus
walls with concomitant orbital floor descent. Due to its rareness, the literature highlights
some confusion on its definition, diagnosis and management. A PRISMA-compliant sys-
tematic review was performed on SSS with focus on definition, diagnosis and therapeutic
management. Twenty-eight studies were selected, with 276 patients evaluated. The analysis
revealed that the leading definition of SSS includes evidence of both enophtalmos and max-
illary atelectasia. Although the definition of SSS accepts only spontaneous sinus collapse,
the presence of sinonasal diseases and history of facial trauma are starting to be included
in the criteria. Most studies (n = 21) considered CT scans satisfactory for diagnosis of SSS,
while 7 also performed MR. The majority of SSS were successfully treated with isolated
functional endoscopic sinus surgery (n = 17), sparing orbital reconstruction as a rescue
procedure in case of non-satisfactory long-term resolution of signs. Although the literature
is starting to coordinate on diagnosis of SSS, our review revealed the necessity of consensus
on its definition and management.
KEY WORDS: silent sinus syndrome, maxillary atelectasia, enophthalmos, imploding
antrum syndrome, silent sinus syndrome management
                                                                                                Received: April 2, 2021
                                                                                                Accepted: November 14, 2021
RIASSUNTO                                                                                       Published online: June 30, 2022
La sindrome del seno silente (SSS) è una rara patologia caratterizzata da collasso delle
pareti del seno mascellare con deiscenza del pavimento orbitario. A causa della rarità          Correspondence
di questa sindrome, la letteratura mostra confusione circa la sua definizione, diagnosi e       Cecilia Rosso
trattamento. È stata condotta una revisione sistematica fedele alle procedure PRISMA sul-       Department of Otorhinolaryngology, San Paolo
la SSS con focus su definizione, criteri diagnostici e trattamento (28 studi, 276 pazienti).    Hospital, University of Milan, via A. di Rudinì 8,
                                                                                                20154 Milan, Italy
L’analisi ha mostrato come la definizione predominante della SSS includa l’evidenza sia
                                                                                                E-mail: rosso.cecilia1@gmail.com
di enoftalmo che di atelettasia mascellare. Sebbene la definizione originaria accetti solo la
presenza di collasso del seno spontaneo, ultimamente la presenza di disturbi nasosinusali e
una storia pregressa di trauma facciale vengono inclusi nei criteri diagnostici. La maggior       How to cite this article: Rosso C, Saibene
parte degli studi (28) ha considerato le immagini TC sufficienti per la diagnosi radiologica,     AM, Felisati G, et al. Silent sinus syndrome:
mentre 7 hanno richiesto anche la RMN.                                                            systematic review and proposal of defini-
Il trattamento prevalente è la FESS (Functional Endoscopic Sinus Surgery) (17 studi), la-         tion, diagnosis and management. Acta Otorhi-
                                                                                                  nolaryngol Ital 2022;42:305-316. https://doi.
sciando l’intervento di ricostruzione orbitaria come procedura di salvataggio in caso di
                                                                                                  org/10.14639/0392-100X-N1598
mancata risoluzione clinica. Sebbene la letteratura inizi a coordinarsi riguardo la diagnosi
di SSS, è necessario un consenso riguardo alla definizione e alla gestione terapeutica.
                                                                                                © Società Italiana di Otorinolaringoiatria
PAROLE CHIAVE: sindrome del seno silente, atelettasia mascellare, sindrome del seno             e Chirurgia Cervico-Facciale
imploso, enoftalmo, gestione sindrome del seno silente
                                                                                                               OPEN ACCESS

                                                                                                This is an open access article distributed in accordance with
Introduction                                                                                    the CC-BY-NC-ND (Creative Commons Attribution-Non-
                                                                                                Commercial-NoDerivatives 4.0 International) license. The
Silent sinus syndrome (SSS) or imploding antrum syndrome is a very rare                         article can be used by giving appropriate credit and mentio-
                                                                                                ning the license, but only for non-commercial purposes and
condition, usually consisting of asymptomatic spontaneous collapse of the                       only in the original version. For further information: https://
sinus walls and floor of the orbit 1. Due to its rarity, the literature has often               creativecommons.org/licenses/by-nc-nd/4.0/deed.en




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highlighted the confusion around its definition, diagnosis        To shed light on these controversies, we performed a sys-                                                                               (25 studies), maxillary atelectasia (MA) (23 studies) and
and proper management.                                            tematic review of the literature on SSS, with particular fo-                                                                            hypoglobus (15 studies), while post-traumatic, facial asym-
The aetiology of SSS remains controversial. Patients typi-        cus on definition, diagnosis and surgical approach.                                                                                     metry and diplopia evidence were less required (respec-
cally deny preexisting sinus disease or orbitofacial trauma.                                                                                                                                              tively, in 3, 3 and 1 studies) as seen in Table II. Moreover,
Most authors postulate that collapse of the inferior orbital      Materials and methods                                                                                                                   7 studies did not directly define diagnostic criteria, which
wall is induced by negative pressure generated by resorp-                                                                                                                                                 were extrapolated from the manuscript.
tion of gas after a natural ostium occlusion that may occur       A PRISMA-compliant systematic literature review 14 was                                                                                  Nine studies included patients with sinonasal symptoms;
during the first or second decade of life 2,3.                    carried out in December 2020 on the Web of Science, Pub-                                                                                6 included post-traumatic cases, and 1 had post-surgical
Clinical appearance usually consists in asymptomatic              Med and Scopus databases, using a search strategy for                                                                                   SSS (Tab. I). Twenty studies diagnosed SSS with CT
enophthalmos and altered facial appearance. Nevertheless,         “(Silent Sinus) AND (Maxillary)” and “(Silent Sinus Syn-                                                                                alone, while 7 performed both CT and MR imaging.
diplopia, sinusitis, rhinorrhoea, post-nasal drip, facial pres-   drome) AND (Maxillary)”.                                                                                                                One study did not define what imaging was performed
sure, or pain may also be present 1,4.                            We included studies focused on SSS with the following cri-                                                                              (Tab. I).
SSS and Chronic Maxillary sinus Atelectasia (CMA) are             teria.                                                                                                                                  Surgical approaches consisted in combined FESS and OR
terms which have been used interchangeably; the latter                                                                                                                                                    in 72 patients, mostly in a one-step surgery. Four studies
can be defined as a persistent and progressive decrease in        Inclusion criteria                                                                                                                      performed both types of timing-choices (one step or two
maxillary sinus volume secondary to inward bowing of the          • Age 1-100 years.                                                                                                                      steps 6 months apart), deciding according to the individu-
antral walls 5.                                                   • Silent sinus syndrome (SSS).                                                                                                          al case. FESS alone was performed in 116 patients; other
Some authors define CMA as SSS, while others sustain that         • Chronic maxillary atelectasia (CMA).                                                                                                  less common therapies were a wait & see approach (57 pa-
the two are separate clinical entities 6,7. For example, ac-                                                                                                                                              tients), OR alone (8 patients) and antibiotic therapy (1 pa-
cording to Ende et al, it is possible to consider three stages    Exclusion criteria                                                                                                                      tient) (Tab. III). A study by Khon et al. did not define their
of CMA: the last, group III, is defined by clinical facial        • Studies whose main purpose was unrelated to SSS char-                                                                                 therapeutical approach in the 22-patient case series 29.
deformity with the onset of ocular disturbances, and may            acteristics and management.                                   Figure 1. PRISMA flow-chart.                                            All patients had clinical resolution (CR) or clinical im-
be also defined as SSS 8. Brandt et al. also argued that SSS      • No human patients involved.                                                                                                           provement (CI). Only Lin and Brown reported 2 patients
should be considered a subtype of CMA 9.                          • Language other than English, Italian, French, German                                                                                  who had FESS surgery alone that did not resolve enoph-
The original definition of SSS dates to 1994 and included           and Spanish.                                                  retrospective and prospective studies were included,                    thalmos, who then underwent subsequent OR 13,16. Compli-
only spontaneous enophthalmos not associated with prior           • Article accepted but not published.                           while case reports and small case series were excluded                  cations are reported in Table I.
trauma or surgery 2. Nevertheless, many authors have started      • Article type: case reports with less than 3 patients, re-     because of their intrinsically lower level of evidence (the
accepting wider inclusion criteria involving more aetiologies       views, comments, letters to the editor, book chapters.        minimum number of patients was arbitrarily set at 3).                   Discussion
(idiopathic, post traumatic, and iatrogenic) and sustain that                                                                     Published reviews on SSS were similarly excluded, but
they should be included in the definition of SSS 10.              Population, Intervention, Comparison, Outcomes,                 their reference list was reviewed to identify possible ad-              SSS is a relatively rare disease that most ENT specialists
Treatment is also a subject under continuous re-evaluation.       and Study (PICOS) criteria                                      ditional studies. A manual search in the reference lists                and ophthalmologists know as an entity, but the sporadic
At first, surgical treatment consisted in Caldwell-Luc sinus      PICOS criteria 15 for the present review were as follows:       of these articles was performed to identify potentially                 evidence leads to ambiguity on many of its aspects, from
surgery with inferior meatotomy and concurrent transcon-          • Patients with CMA or SSS diagnosis.                           relevant papers missed during the database search. Dif-                 definition, to diagnostic criteria to treatment.
junctival repair of the orbital floor. In 1993, Blackwell et      • Intervention: evaluation of definition, diagnostic criteria   fering opinions were resolved by consensus between the
al. described endoscopic maxillary antrostomy (FESS:                and treatment.                                                two authors. Data extracted and analysed included study                 Definition
functional endoscopic sinus surgery) in conjunction with a        • Comparison: comparison of different definitions, di-          design, sample size, mean patient age, diagnostic crite-                Our systematic review revealed that among the 28 stud-
transconjunctival orbital floor repair (OR) in three patients       agnosis and therapeutical options (FESS + OR, FESS            ria, associated factors, instrumental diagnosis, surgical               ies evaluated, the most required diagnostic criteria were
and reported resolution of maxillary disease on follow-up           alone, OR alone, antibiotic therapy, wait & see).             approach and timeline, outcomes, complications and                      evidence of enophthalmos (25 studies) and maxillary at-
and no recurrence of enophthalmos 1.                              • Outcome: proposal of shared definition, diagnostic cri-       follow-up time.                                                         electasia (MA) (23 studies), with 21 requiring both signs.
Nowadays, the leading treatment of SSS, in order to restore         teria and treatment.                                                                                                                  Hypoglobus observation follows as essential criteria in
the natural ventilation of the maxillary sinus, appears to be     • Study design: Retrospective case studies and case series                                                                              15 studies, also with evidence of orbital floor remodeling at
FESS 11. Instead, the main controversy in literature remains        (more than 3 patients) were enrolled in the review.
                                                                                                                                  Results                                                                 CT scans (11 studies) and the absence of sinonasal diseases
the necessity and timing of the orbital floor reconstruc-                                                                         The systematic review retrieved 28 original arti-                       (10 studies) (Tab. II).
tion via a subconjunctival approach. Some authors prefer          Data extraction and quality assessment                          cles 3,4,6,7,10-13,16-19,21,23-37. Twenty-one were retrospective case   Therefore, even if there is much misunderstanding around
a one-stage approach, with endoscopic antrostomy and              Two of the authors (CR and CP) independently screened           studies (RCS), while 7 were case reports reporting at least             the definition of SSS, it is possible to assume that most
reconstruction of the orbital floor performed at the same         the retrieved studies based on title and abstract; when         3 cases. A total of 276 patients were evaluated with a mean             authors agree in having both enophthalmos and MA as
time 10,12. Others believe that a two-stage approach is more      uncertainty existed in the abstract evaluation, we re-          of 9.8 cases per study (range 3-57). Mean age was 40.4                  necessary criteria. Only 2 studies required only MA in the
convenient, with a delay between antrostomy and the orbit-        trieved and assessed the full text. After completion of all     years, although 3 papers did not report the age of partici-             absence of enophthalmos, considering CMA and SSS as a
al reconstruction of 6 months 13. Still others consider FESS      searches, duplicates were removed. Evaluation through           pants (Tab. I). There was a wide variety of diagnostic cri-             same entity 4,17.
alone to be the best choice of therapy with less invasiveness     full-text screening was then carried out. Critical ap-          teria among studies (Tab. II). The most frequently required             Post-traumatic silent sinuses were originally excluded from
and satisfactory results, with no need of OR 6.                   praisal led to the selection of 28 studies (Fig. 1). Both       findings for diagnosis were evidence of enophthalmos (En)               the definition of SSS 18,19, and some recent papers continue



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Table I. Baseline data of studies included.
 Study (year)                          Study      Sample      Mean age                               Diagnostic criteria                           Associated factors      Diagnosis     Surgical          Surgical        Outcome               Complications            Follow-up
                                       design      size    (range) in years                                                                                                              approach          timeline                                                       (months)
 Behbehani 25 (2006)                                5       36.7 (32-42)                                     En                                     Post-traumatic (1)     CT scans    FESS and OR (5)   One step (5)    100% CI or CR        Residual 1mm En (2)             24
                                       RCS                                                               Hypoglobus                                Chronic sinusitis (4)                                                                      Transient infraorbital
                                                                                                            MA                                                                                                                                 hypoaesthesia (1)


 Bossolesi 18 (2008)               Case reports     4        42 (38-45)                                      En                                    Chronic sinusitis (2)     End       FESS and OR (4)   One step (4)      100% CR                    None                  12-24
                                                                                                  Opacified maxillary sinus                                                  CT
                                                                                             Absence of major sinus pathology                                                MR
                                                                              Absence of previous trauma, surgery or congenital facial deformity
 Brown 16 (2017)                 RCS and review     6            43                                          En                                    Chronic sinusitis (1)      CT           FESS (1)      One step (1)       100% CI           Residual 2 mm En (1)        Not defined
                                                               (35-52)                                      MA                                      Post-traumatic (6)                      OR (1)       Two steps (3)                          minor diplopia (1)
                                                                                                         Hypoglobus                                                                    FESS and OR (4)
 Chariba 11 (2014)                     RCS          13       34 (13-61)                                      En                                    Chronic sinusitis (5)      CT          FESS (13)          N/A            100% CI             Orbital breach (2)            30
                                                                                                            MA
 Chavez-Montoya 26 (2017)              RCS          3            44                                         MA                                     Nasal polyposis (1)        CT          FESS (1)       One step (1)       100% CI                     -                     24
                                                               (37-48)                            Opacified maxillary sinus                                                            FESS and OR (1)
                                                                                                                                                                                        Wait & see (1)
 Claròs 12 (2015)                  Case reports     3       36.3 (25-45)                                Not defined                                         -                 CT        FESS + OR (3)    One step (3)      100% CR                    None                Not defined
                                                                                                             En
                                                                                                        Hypoglobus
                                                                                               Low pressure in maxillary sinus

 Claròs 10 (2019)                      RCS          13       38 (25-53)                                 Not defined                                         -                 CT       FESS + OR (13)    One step (13)      100% CI                   None                Not defined
                                                                                                              En
                                                                                                        Hypoglobus
                                                                                                   Orbital floor resorption
                                                                                                              MA
                                                                                     Absence of trauma and congenital facial deformity
 Cobb 21 (2012)                    Case reports     3        44 (30-60)                                       En                                   Post-traumatic (2)         CT       FESS and OR (3)   One step (2)       100% CI                   None               12 (1) 36 (1)
                                                                                                              MA                                    Post-surgical (1)         MR                         Two steps (1)                                                      48 (1)
                                                                                                     Maxillary opacity
 De Dorlodot 7 (2017)                  RCS          4        44 (12-60)                              Facial asymmetry                                       -                 CT          FESS (3)       Two steps (1)      100% CI        Slight enophtalmos in some     Not defined
                                                                                                   En and/or hypoglobus                                                                FESS and OR (1)                                      patients (No. not defined)
                                                                                                              MA
                                                                                             Absence of sinonasal symptoms
 Eyigor 6 (2016)                       RCS          16      42.37 (20-66)                                     MA                                            -                 CT          FESS (16)          N/A             Ongoing           Ongoing follow-up            Ongoing
                                                                                                              En                                                              MR                                            follow-up
                                                                                              Absence of trauma or sinusitis
 Farneti 3 (2017)                RCS and review     6         10 (7-14)                             Absence of sinusitis                                    -                 CT          FESS (6)           N/A           100% CR           Residual headache (1)          18-135
                                                                                        Remodeling of orbital floor at CT/MR scans
                                                                                                 Opacified maxillary sinus
                                                                                       Absence of trauma or congenital deformities
 Freiser 13 (2020)                     RCS          57      12.5 (3.7-18)                               Not defined                                         -                 CT         FESS (19)           N/A         100% CI or CR             Not defined            Not defined
                                                                                                              En                                                                       Wait & see (38)
                                                                                                        Hypoglobus
                                                                                                              MA

 Gaudino 23 (2013)                     RCS          6        44 (22-67)                                      En                                             -                 CT          FESS (1)       One step (1)      2 FESS: no              Not defined            Not defined
                                                                                                          Diplopia                                                            MR       FESS and OR (2)   Two steps (1)    significant CI
                                                                                                       Opacified sinus                                                                  Wait & see (3)                     2 FESS and
                                                                                                            MA                                                                                                                OR: CI




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Table I. Baseline data of studies included (follows).
 Study (year)                          Study            Sample       Mean age                            Diagnostic criteria                         Associated factors         Diagnosis          Surgical              Surgical        Outcome               Complications            Follow-up
                                       design            size     (range) in years                                                                                                                 approach              timeline                                                       (months)
 Illner 27 (2002)                        RCS              5          47 (39-65)                               Not defined                                      -                  CT/MR             FESS (3)               N/A           Not defined             Not defined            Not defined
                                                                                                                   En                                                                         Antibiotic therapy (1)
                                                                                                              Hypoglobus                                                                         Wait & see (1)
                                                                                                 Maxillary sinus completely developed
                                                                                                       Maxillary sinus opacified
                                                                                                        Infundibulum occluded
 Kashima 28 (2016)                       RCS              11        39.5 (23-62)                              Not defined                                Not defined            Not defined    FESS and OR (11)        One step (11)      100% CI        Residual enophthalmos (1)           9
                                                                                                                  MA                                                                                                                                      1 mm over correction (1)
                                                                                                                   En                                                                                                                                    Lower eye-lid retraction (1)
                                                                                                              Hypolgobus                                                                                                                                Nasolacrimal duct obstruction
                                                                                                                                                                                                                                                                     (1)

 Kohn 29 (2013)                          RCS              22        41.2 (22-70)                                  En                               Chronic rhinosinusitis (9)     CT/MR           Not defined           Not defined      Not defined             Not defined            Not defined
                                                                                                              Hypoglobus                             Post-traumatic (10)
                                                                                                                  MA
                                                                                                     Orbital changes at CT scans
 Korn 17 (2009)                     Case reports          5         Not defined                                   MA                               Chronic rhinosinusitis (2)       CT          FESS and OR (5)        One step (5)       100% CI          Transient infraorbital       Not defined
                                                                                                       Orbital floor resorption                                                                                                                              Hypoaesthesia (1)
                                                                                                                                                                                                                                                            Residual diplopia (1)
 Lee 30 (2018)                      Case reports          3         44.6 (37-55)                                   En                                 Post-traumatic (1)           CT              FESS (1)                N/A            100% CI           Residual diplopia (1)       Not defined
                                                                                                              Hypoglobus                                                           MR               OR (1)                                               Residual enophthalmos (1)
                                                                                                                   MA                                                                            Wait & see (1)
                                                                                                       Opacified maxillary sinus
 Lin 31 (2015)                           RCS              9         Not defined                                    MA                                 Post-traumatic (1)            CT             FESS (7)            Two steps (2)      2 FESS                    None                   21.4
                                                                                                        Orbital floor resorption                                                                FESS and OR (2)                          alone did
                                                                                                                   En                                                                                                                   not resolved
                                                                                                         Absence of sinusitis                                                                                                          enophthalmos
                                                                                                                                                                                                                                          and so
                                                                                                                                                                                                                                       underwent OR
 Martìnez-Capoccioni 32                  RCS              20        44.2 (28-67)                         En and/or Hypoglobus                        Nasal obstruction (9)          CT            FESS (15)                N/A           100% CI                    None                   6-18
 (2016)                                                                                                Endoscopic findings of MA                                                                 Wait & see (5)
                                                                                                       Altered facial appearance
                                                                                       Maxillary contraction and orbital enlargement at CT scans
 Rose 33 (2003)                          RCS              14        41.3 (25-78)                              Not defined                                      -                    CT              OR (6)                 N/A            100% CI                   None                   5-33
                                                                                                                   En                                                                            Wait & see (8)
                                                                                                              Hypoglobus
                                                                                                       Remodeling of orbital floor
                                                                                                       Absence of nasal diseases

 Sesenna 34 (2010)                  Case reports          3          39 (28-46)                                    En                                          -                    CT          FESS and OR (3)        One step (2)      100% CR                    None                  10-16
                                                                                                               Hypoglobus
                                                                                                                  MA
                                                                                        Absence of sinusitis, trauma and congenital deformities
                                                                                                Orbital floor remodeling at CT scans
 Sivasubramaniam 35 (2011)               RCS              18     Not defined (19-54)                    En and/or Hypoglobus                                   -                    CT             FESS (18)               N/A            78% CR         Residual enophthalmos (1)        15-120
                                                                                                                  MA                                                                                                                      17% CI
                                                                                                      Altered facial appearance
                                                                                                         Absence of sinusitis
 Thomas 22 (2003)                        RCS              4          32 (27-35)                                    En                                          -                    CT          FESS and OR (2)        Two steps (2)     100% CR         Residual enophthalmos after    Not defined
                                                                                                         Absence of sinusitis                                                                      FESS (2)                                             FESS alone (2) which required
                                                                                                                  MA                                                                                                                                     second step surgery with OR
                                                                                                       Opacified maxillary sinus
                                                                                                    Inferior bowing of orbital floor



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Table I. Baseline data of studies included (follows).
 Study (year)                          Study                   Sample           Mean age                                        Diagnostic criteria                           Associated factors      Diagnosis        Surgical             Surgical        Outcome               Complications            Follow-up
                                       design                   size         (range) in years                                                                                                                          approach             timeline                                                       (months)
 Vander Meer 4 (2001)                        RCS                   4            42 (38-47)                                              En                                             -                 CT         FESS and OR (4)       One step (4)      100% CR                    none                   2-36
                                                                                                                                       MA
                                                                                                            Absence of sinusitis, trauma or congenital deformities
                                                                                                                   Remodeling of orbital floor at CT scans
 Virgin 36 (2008)                            RCS                   5            42 (22-65)                                              En                                             -                 CT            FESS (4)           Two steps (1)     100% CR                    None                    24
                                                                                                                                       MA                                                                           FESS and OR (1)
 Wan 37 (2000)                           Case reports              3            41 (38-44)                                        Not defined                                 Chronic sinusitis (1)      CT            FESS (3)               N/A           100% CR                    none                    N/A
                                                                                                                                        En
                                                                                                                                  Hypoglobus
                                                                                                                                       MA
                                                                                                                           Remodeling orbital floor
 Wise 19 (2007)                             RCS                   11                46.5                                                En                                             -                 CT            FESS (3)           Not defined       Not defined                none                Not defined
                                     Focused only on CT                           (11-70)                                 Opacified maxillary sinus                                                                 FESS and OR (8)
                                          findings                                                                         Orbital floor remodelling
                                                                                                         Absence of chronic sinusitis, trauma or congenital deformities
RCS: retrospective case study; En: enophthalmos; MA: maxillary atelectasia; FESS: functional endoscopic sinus surgery; OR: orbital reconstruction;
CI: clinical improvement; CR: clinical resolution; End: nasal endoscopy.



considering post-traumatic cases not definable as SSS due                                    Definition proposal                                                          of anatomical impairment and diplopia, if present. Among            A total of 116 patients underwent FESS surgery alone, be-
to their lack of spontaneous development 10,20.                                              Our proposal for definition is:                                              these, the majority (n = 9) performed both the procedures           ing considered as a necessary and sufficient procedure to
Nevertheless, a retrospective analysis of 6 cases and litera-                                • criteria to diagnose SSS are contemporary presence of                      simultaneously, while 4 preferred to first carry out FESS           resolve MA and enophthalmos (Tab. III). If we consider
ture review showed how traumatic SSS management fol-                                           enophtalmos and maxillary atelectasia;                                     surgery and to observe a possible progressive improvement           the entire case series of the review, FESS alone appears as
lows the same principles as for spontaneous SSS 21. In fact,                                 • minor associated factors may be the presence of sinona-                    of the enophtalmos to decide whether or not to perform              the leading therapeutic choice, with only 7 reporting re-
our analysis revealed that recent papers started to include                                    sal diseases and history of facial trauma.                                 additional OR. Eventually, 3 studies performed FESS and             sidual enophthalmos (6%), and 4 requiring subsequent OR
enophthalmos with MA secondary to traumatic events in                                                                                                                     either simultaneous or delayed OR according to the criti-           (3.4%). Moreover, Numa et al. undertook a review of 84
the group of SSS, explaining that clinical and radiologi-                                    Diagnosis                                                                    cality of the case (Tab. III).                                      cases and concluded that for patients with SSS diagnosis,
cal presentations are comparable, as well as surgical treat-                                 Most studies only required CT for imaging investigation,                     The reasons which guide each surgical team towards one              uncinectomy alone may be sufficient 24.
ment 13,21,22.                                                                               since the relevance was to investigate maxillary bony walls                  choice or another are multiple. The main factor is undoubt-         FESS + OR follows with 72 cases treated with this manage-
Moreover, the association of SSS with sinonasal symptoms                                     atelectasia with possible resorption of the orbital floor.                   edly the severity of enophthalmos and hypoglobus, al-               ment. Wait & see (57 patients) may be a valid alternative
is debated. Ten studies considered the evidence of sinonasal                                 Nevertheless, 7 groups also considered it useful to add MR                   though no study defined a quantitative cut-off which could          in asymptomatic cases or young population 13. OR alone
symptoms as an exclusion criterion because MA secondary                                      scans (Tab. I) to evaluate:                                                  help in the surgical decision. OR approach is supported by          (8 patients) and antibiotic therapy (1 patient) remain mar-
                                                                                             • dislocation of extra and intra-conical fat, extrinsic ocular               the fact that, although there have been reports of resolution       ginal therapeutic options (Tab. III).
to chronic sinusitis with sinus dysventilation and sinona-
                                                                                                muscles and optic nerve;                                                  of the progression of enophthalmos by antrostomy alone,             This leads us to the conclusion that most of SSS may be
sal symptoms is, by those authors, considered as CMA and
                                                                                             • differentiation between mixed signal central secretions                    it is unclear whether other aesthetic deformities caused by         successfully treated with isolated FESS surgery, sparing
not as SSS 9. At the same time, the majority of studies do
                                                                                                and high signal peripheral;                                               SSS as hypoglobus or superior sulcus deformity also re-             OR as a rescue procedure in case of non-satisfactory reso-
not clarify this point, and include among SSS subjects who
                                                                                             • thick edematous mucosal lining within the maxillary si-                    spond. Behbehani et al. believe that delaying orbital im-           lution of enophthalmos or diplopia.
have associated factors such as sinusitis, chronic nasal con-
                                                                                                nus 6,18,23.                                                              plant placement in cases with significant enophthalmos and
gestion and other sinonasal symptoms of obstruction, even                                                                                                                 hypoglobus is unjustified since complications like diplopia         Treatment proposal
though these are not considered diagnostic criteria (Tab. II).                               Diagnostic proposal                                                          or infection are rare with this procedure. Furthermore, si-         FESS is the leading treatment for SSS and orbital recon-
Finally, 7 studies did not specify diagnostic criteria, which                                Only CT scan is required. MR imaging can be associated in                    multaneous implant placement also obviates the need for             struction should be performed only in selected and symp-
were extrapolated from the clinical description of cases.                                    selected cases, and specifically to evaluate a marked hypo-                  additional anaesthesia and hospitalisation 25. Cobb et al.          tomatic cases or, if needed, in a second approach when no
This risks producing inaccurate studies given that the lit-                                  globus. We propose to add evaluation of extraocular mus-                     maintain that FESS alone may stop the descent of the or-            resolution is seen. The proposed timepoint for a potential
erature lacks in consensus in SSS diagnosis and the reader                                   cle movement and potential diplopia at first ENT clinical                    bital wall, but there would be no reason to expect that the         postponed OR, according to the literature, is 6 months.
may find its definition confusing.                                                           evaluation, in order to select symptomatic and therefore the                 position of the orbital floor, and thus the globe, would be         Our review clearly shows the need to develop consensus
From our analysis, it appears that the leading definition                                    most critical cases 10,20.                                                   reversed 21.                                                        regarding the definition of SSS and most of all its man-
of SSS should include the evidence of enophthalmos and                                                                                                                    On the contrary, Thomas et al. support delayed repair of            agement. Even if the literature has started to find mar-
maxillary atelectasia. We believe that presence of sinona-                                   Treatment                                                                    the orbital floor as in some patients enophthalmos improves         ginal consensus in recent years, it appears necessary to
sal diseases and history of facial trauma may be reasonable                                  The review also showed disagreement on management                            with antrostomy alone 22. Moreover, OR has not been shown           define shared diagnostic criteria, as well as a shared ap-
factors to be included in anamnestic data because of the                                     strategies. Seventeen authors proposed combined FESS                         to provide any significant restoration in the orbital muscle        proach to the best treatment choices with the lowest rate
comparable clinical presentation and treatment.                                              and OR surgery as the leading therapy to obtain resolution                   functions, and because of that diplopia is not corrected 6.         of invasiveness and morbidity. The literature would also



312                                                                                                                                                                                                                                                                                                                  313
C. Rosso et al.                                                                                                                                                                                                                    Analysis of 276 cases and addressing towards a shared consensus




Table II. Summary of diagnostic criteria for SSS.                                                                                                 Table III. Summary of therapeutic strategies for SSS.
 Not       Study (year)         En Hypoglobus MA         Opacified   No previous    No            Post-      Facial    Diplopia   Orbital floor    Study (year)                                           FESS + OR       FESS                 OR              Wait & see          Antibiotic
 directly                                                maxillary     trauma,   sinonasal     traumatic   asymmetry              remodeling                                                                                                                                        therapy
 defined                                                  Sinus       surgery or symptoms                                            at CT         Behbehani 23 (2006)                                      X (5)
                                                                     congenital
                                                                     deformities                                                                   Bossolesi 16 (2008)                                      X (4)
             Behbehani 25 (2006) X             X    X                                                                                              Brown 14 (2017)                                          X (4)          X (1)               X (1)
             Bossolesi 18 (2008) X                          X            X             X                                                           Chariba 11 (2014)                                                      X (13)
             Brown 16 (2017)       X           X    X                                              X                                               Chavez-Montoya 24 (2016)                                  X (1)         X (1)                                  X (1)
             Chariba 11 (2014)     X                X                                                                                              Claròs 12 (2015)                                          X (3)
             Chavez-Montoya 26                      X       X                                                                                      Claròs 10 (2019)                                         X (13)
             (2017)                                                                                                                                Cobb 19 (2012)                                            X (3)
 x           Claròs 12 (2015)      X           X    X                                                                                              De Dorlodot 7 (2017)                                      X (1)         X (3)
 x           Claròs 10 (2019)      X           X    X                    X                                                                         Eyigor 6 (2016)                                                        X (16)
             Cobb (2012)
                     21
                                   X                X                                              X                                               Farneti 3 (2017)                                                        X (6)
             De Dorlodot 7         X           X    X                                  X                        X                                  Freiser 13 (2020)                                                      X (19)                                 X (38)
             (2017)                                                                                                                                Gaudino 21 (2012)                                        X (2)          X (1)                                  X (3)
             Eyigor 6 (2016)       X                X                    X                                                                         Illner 25 (2002)                                                        X (3)                                  X (1)               X (1)
             Farneti 3 (2017)                               X            X             X                                               X           Kashima 26 (2016)                                        X (11)
 x           Freiser 13 (2020)     X           X    X                                                                                              Kohn 27 (2013)                                              -            -                   -                   -                  -
             Gaudino 23 (2013)     X                X       X                                                             X                        Korn 17 (2009)                                            X (5)
 x           Illner 27 (2002)      X           X            X                                                                                      Lee 28 (2019)                                                           X (1)               X (1)              X (1)
 x           Kashima 28 (2016)     X           X    X                                                                                              Lin 29 (2015)                                            X (2)          X (7)
             Kohn (2013)
                     29
                                   X           X    X                                                                                  X           Martìnez-Capoccioni 30 (2016)                                          X (15)                                  X (5)
             Korn 17 (2009)                         X                                                                                  X           Rose 31 (2003)                                                                              X (6)              X (8)
             Lee 30 (2018)         X           X    X       X                                                                                      Sesenna 32 (2010)                                        X (3)
             Lin (2015)
                  31
                                   X                X                                  X           X                                   X           Sivasubramaniam 33 (2011)                                              X (18)
             Martìnez-             X           X    X                                                           X                      X           Thomas 20 (2002)                                         X (2)          X (2)
             Capoccioni 32 (2016)
                                                                                                                                                   Vander Meer 4 (2001)                                     X (4)
 x           Rose 33 (2003)        X           X                                       X                                               X
                                                                                                                                                   Virgin 34 (2008)                                         X (1)         X (4)
             Sesenna 34 (2010)     X           X    X                    X             X                                               X
                                                                                                                                                   Wan 35 (2000)                                                          X (3)
             Sivasubramaniam 35 X              X    X                                  X                        X
             (2011)                                                                                                                                Wise 17 (2007)                                           X (8)         X (3)
             Thomas 22 (2003)      X                X       X                          X                                               X           TOTAL                                                     17            17                   3                   7                  1
             Vander Meer 4         X                X                    X             X                                               X           TOTAL PER CASES                                           72           116                   8                  57                  1
             (2001)
             Virgin 36 (2008)
             Wan 37 (2000)         X                 X                                                                                            Acknowledgements                                                    Author contributions
 x           Wise 19 (2007)        X            X    X                                                                                  X         We gratefully thank the Librarians from the Università              CR made a substatial contribution to the conception and
 7           TOTAL                24           15   23      7            6             9           3            3         1            10         degli Studi di Milano, Biblioteca del Polo Centrale. With-          design of the article, to the acquisition, analysis and inter-
En: enophthalmos; MA: maxillary atelectasia.                                                                                                      out their help, we would not have been able to locate and           pretation of data. AMS and GF critically revised the article
                                                                                                                                                  analyse a significant number of the studies included in this        and gave the final approval of the version to be published.
                                                                                                                                                  systematic review.                                                  GP made a substatial contribution to the conception and
benefit from prospective studies on the best outcome in                      atelectasia by CT. Hypoglobus, presence of sinonasal dis-
                                                                                                                                                                                                                      design of the article and gave the final approval of the ver-
SSS management.                                                              eases and history of facial trauma may or may not be as-             Conflict of interest statement                                      sion to be published.
                                                                             sociated, although the clinical relevance and management             The authors declare no conflict of interest.
Conclusions                                                                  seems to be comparable. FESS alone appears to be the first                                                                               References
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