Dental Computed Tomography (CBCT) to Identify Dental Sources of Maxillary Sinusitis

CBCT by J. Morita Veraviewepocs 3De

As endodontists, the use of CBCT (Cone Beam Computed Tomography) has allowed us to cross this barrier and diagnose dental pathology which is adversely affecting the maxillary sinuses.  These images also allow us to communicate more effectively with patients and physicians who are trying to manage and treat these chronic sinus issues.  In order for dental and medical specialists to work together, new paths of communication must be developed.  CBCT (3D imaging) is helpful in bridging the communication gap between dentistry and medicine.

The following cases demonstrate the usefulness of CBCT in identifying odontogenic sources of chronic sinusitis.  Several radiographic findings are pointed out which help identify odontogenic sources for chronic sinusitis.  These common findings seen with high resolution CT imaging include:

1. Perforation of the floor of the Mx sinus
2. "Halo effect" elevation of the floor of the Mx sinus
3. Thickening of sinus membrane adjacent to odontogenic infection
4. Air bubbles in the sinus suggested of an acute sinusitis

CBCT for DIAGNOSIS
CBCT (J. Morita Veraviewepocs 3De) demonstrates a large periapical radiolucency around the buccal roots of #15.  The sagittal view shows elevation in the floor of the sinus (halo effect).  Coronal view shows arrow pointing to a missed mesio-buccal canal causing the endodontic infection. Air bubbles seen in the maxillary sinus are indicative of an acute sinusitis. Endodontic retreatment is required BEFORE sinus treatment.  Failure to address the odontogenic source of the sinus infection will result in recurrent sinus infections.

CBCT for DIAGNOSIS
CBCT (J. Morita Veraviewepocs 3De) demonstrates a large periapical radiolucency around the mesio-buccal root.  The sagittal and coronal views both show elevation in the floor of the sinus (halo effect) as well as perforation of the floor of the sinus.  Endodontic treatment is required BEFORE sinus treatment.  Failure to address the odontogenic source of the sinus infection will result in recurrent sinus infections.

CBCT for DIAGNOSIS
CBCT (J. Morita Veraviewepocs 3De) demonstrates a large periapical radiolucency around the buccal roots of #3.  The sagittal and coronal views both show elevation in the floor of the sinus (halo effect) as well as perforation of the floor of the sinus.  Endodontic treatment is required BEFORE sinus treatment.  Failure to address the odontogenic source of the sinus infection will result in recurrent sinus infections.

Fortunately, these high definition images also identify the problems with previous endodontic treatment and the solutions to remove the odontogenic source of infection.  These common endodontic findings include:

1. Missed (untreated) canals in a previously treated root canal
2. Short filled canals in a previously treated root canal
3. Iatrogenic damage in a previously treated root canal

Proper endodontic treatment of the dental infection is the first step in addressing the chronic sinusitis of odontogenic origen.  If sinus symptoms persist, following endodontic treatment, then referral to ENT is recommended.

Is This Tooth Bothering My Sinuses?

"Is this tooth bothering my sinuses?" For years patients with chronic sinus issues have asked this question at the dental office.  Unfortunately, there has been a communications gap between diagnostic medicine and dentistry in this overlapping area of practice.  Endodontists are experts diagnosing pulpal disease, but not trained in diagnosis of sinusitis. Most otolarygologists (ENT) physicians, and especially rhinologists, are experts in sinus diagnosis, but not trained in evaluating dental and pulpal infection, which may be a source of infection for the sinuses. Most sinus CTs are not including the teeth and rarely are medical radiologists evaluating the teeth in their reads.

In cooperation with Dr. Tim Haegen of the Arizona Sinus Center, a division of Valley ENT, we have been able to help patients with chronic sinus issues. Many of these patients have bounced from ENT to ENT looking for answers, some have had continuous courses of antibiotics and some have had sinus surgery, only to continue to have chronic sinus issues. With some interdisciplinary education between endodontics and otolaryngology, familiarization with each other's diagnostics and terminology and the use of medical and dental CT imaging, we are working together to diagnose and treat the often time overlooked odontogenic sources of sinusitis.  The use of 3D imaging between disciplines has helped to bridge the gap of communication between medical and dental specialists trying to help patients with sinusitis and dental infections.

The following case demonstrates how proper understanding of endodontic and ENT imaging, diagnostics and terminology facilitate proper diagnosis and treatment.

This patient presented to Arizona Sinus Center for evaluation of chronic sinus issues.  She presented with chronic, unilateral nasal and facial symptoms, along with foul smelling nasal discharge.  Nasal endoscopy was performed and findings include:



FINDINGS:

• Nasal septum - superior deviation to right, mucosa intact, no perforation or crust
• Right inferior turbinate - normal
• Right middle turbinate - edematous
• Right middle meatus - closed; edematous medialized uncinate. Tissue is pulsatile. No purulence or polyps.
• Right posterior choanae - normal
• Left inferior turbinate - normal
• Left middle turbinate - normal
• Left middle meatus - open, no mucopus or polyps
• Left posterior choanae - normal
• Nasopharynx - no masses

RADIOGRAPHIC FINDINGS:

 Complete opacification of the right frontal sinus.

Partial opacification of the R ethmoid sinuses.

Complete opacification of R maxilliary sinus, superior septal deviation to the right, bilateral opacified concha bullosas.

Molar #2 and #3 have periapical radiolucency (PARL), one of which is dehiscent into the maxillary sinus and buccal gingival sulcus.  This may be the most important diagnostic information in the CT scan.  Too often, radiologists and otolaryngologists are not looking at this part of the scan - if it is even included in the field of view.

Following evaluation, the following impressions were recorded.

Impression:

• Nasal Obstruction
• Deviated nasal septum
• Frontal sinusitis, chronic
• Maxillary sinusitis, chronic
• Ethmoidal sinusitis, chronic
• Dental caries, unspecified
• Disturbances of sensation of smell and taste

 With these radiographic findings and clinical impressions, the patient was then referred to Superstition Springs Endodontics for evaluation and definitive treatment of the maxillary molars #2 and #3.  Due to the complete opacification of multiple sinuses along with bony erosion of the medial orbital wall, the possibility of endoscopic sinus surgery was discussed.  Discussion included risks of failure to treat the infection within the sinuses as well as failure to remove the source of the infection, which in this case has to include the dental source of infection.

Pt presents for endodontic evaluation of #2 and #3 following ENT identification of possible dental abscess adjacent to Mx sinus.

Endodontic diagnosis, including CBCT, determines that tooth #2 has a prior root canal with a root fracture and extraction is recommended.  Tooth #3 has a prior RCT with apical abscess - caused by a missed MB#2 canal during the initial root canal treatment.  Retreatment of the root canal #3 is recommended.

Endodontic retreatment with microscope locates the previously missed MB#2 canal.

MB#2 canal is debrided and irrigated with NaOCl.

PostOp radiograph shows all 4 canals have been properly treated.

PeriApical RadioLucency (PARL) seen at apex of MB root - which had a missed canal on initial treatment.

6 month recall following endodontic retreatment shows healing of the PARL.

After 6 months, extraction of tooth #2 and retreatment of tooth #3 has shown periapical healing.  The potential odontogenic source of the sinus infection has been eliminated.  Since the Mx sinus continues to show opacification, the patient is referred back to Dr. Haegen for continued sinus evaluation and treatment.

Why See An Endodontist?

Dental Operating Microscope used by endodontists

The endodontists at Superstition Springs Endodontics are experts in endodontic diagnosis and have extensive experience with CBCT.  In addition, endodontists are specially trained to perform the most difficult endodontic cases.  Maxillary molars, most closely associated with the maxillary sinus, almost always have 4 canals.
A common reason for root canal failure on Mx molars is inadequte cleaning, and often completely missing the MB#2 canal.  Endodontists using an operating microscope are able to find and treat the MB#2 (4th canal) more effectively and efficiently.  Endodontist are also trained to perform endodontic microsurgery when traditional endodontic therapy is unsuccessful.

When endodontists and otolaryngologists work together, they can provide the best care for patients with odontogenic sinusitis. 

Resolution of Odontogenic Sinusitis after RCT Retreatment

The use of CBCT in endodontics is helpful in the diagnosis and treatment of sinusitis of odontogenic origin.  The following case demonstrates how proper endodontic treatment will resolve an asymptomatic sinusitis of odontogenic origin.

Pt reports swelling, throbbing, percussion pain but reports no sinus symptoms of congestion, drainage, restricted airflow through the nose or sinus headaches.



CBCT take for further evaluation of prior RCT.  CBCT shows missed MB#2, thickened sinus membrane, large pa lesion on MB with elevated sinus floor (halo effect). DX: Prior RCT with acute apical abscess & odontogenis sinusitis.

Missed MB#2 canal seen in axial view.



Slight halo effect

RCT Retx completed.

7 Month Recall



7 month recall.  Pt is asymptomatic. CBCT shows resolution of the previously thickened sinus membrane, healing of periapical lesion, previous elevation of the sinus floor has resolved.  All signs and symptoms have resolved.

 

Odontogenic Rhinosinusitis - An Introduction

Recently, an article in the Journal of Otolaryngology, Head and Neck Surgery, extrapolated data from a County hospital in Minnesota and calculated a national cost of inpatient hospital care for odontogenic deep neck space infections to be $200 million annually (1).  Absent from this article was any mention of the cost or incidence of odontogenic rhinosinusitis.  The reported incidence in the literature of dental pathology as a cause of rhinosinusitis is 10-12% (2).  The primary source data for this incidence is from the 1950s and there is no documentation in the referenced articles of the data used to calculate this incidence.  Therefore, the true incidence odontogenic rhinosinusitis is unknown and, based on my experience, most likely underappreciated. 

By BruceBlaus (Own work) via Wikimedia Commons

Prior to reviewing odontogenic rhinosinusitis, we need to discuss common definitions.  Rhinosinusitis is inflammation of the paranasal sinus and/or nasal cavities.  This inflammation may be caused by allergic, infectious or immunogenic etiologies.  Acute rhinosinusitis lasts up to 4 weeks, subacute rhinosinusitis lasts up to 12 weeks, and chronic rhinosinusitis lasts greater than 12 weeks.  Acute rhinosinusitis is a clinical diagnosis based on the history and physical exam.  Symptoms of sinusitis have been divided among major and minor factors (3).  The diagnosis requires either two major factors or one major factor and 2 minor factors.  Major factors include facial pain, facial congestion, nasal obstruction (blockage), purulent (discolored) nasal drainage (anterior or posterior), lack of or absence of smell, or fever.  Minor symptoms include headache, fatigue, halitosis (bad breath), and dental pain, cough or ear pressure or pain.

Major Symptoms	Minor Symptoms
Facial Pain	Headache
Facial Congestion	Fatigue
Nasal Obstruction	Halitosis
Purlent Drainage	Dental Pain
Loss of Smell	Cough
Fever	Ear Pressure/Pain

Odontogenic rhinosinusitis is defined as sinusitis induced by a dental lesion.  The common etiologies include periapical and periodontal disease, odontogenic lesions and iatrogenic and traumatic causes.  Iatrogenic causes include complications of tooth extractions, implants, sinus augmentation, osteotomies and other orthodontic surgery, and a foreign body reaction to either the root canal sealant or filling material used in root canal therapy.  A significant amount of literature is dedicated to complications associated with dental implants and sinus lifts.  The reported incidence of rhinosinusitis resulting from sinus augmentation is 0-27% (4).  However, when strict criteria are used to define rhinosinusitis, the incidence is 4.5%.  Approximately 1/3 of these patients will progress from acute to chronic rhinosinusitis.  Chronic rhinosinusitis requiring surgical intervention from sinus augmentation is reported to be 1.3% of patients(4).  Sinus inflammation consisting of mucous membrane thickening on preaugmentation CT imaging is a statistically significant risk factor for post procedure acute or chronic rhinosinusitis (5). These are patients who would benefit from a preaugmentation ENT evaluation.

Treatment of sinusitis consists of saline irrigations, topical and systemic decongestants, antibiotics, topical and systemic steroids and allergy treatment.  Antibiotics are used to treat acute rhinosinusitis and acute exacerbations of chronic rhinosinusitis.  The specific antibiotic used is based on common microbiology patterns or the result of endoscopically-guided cultures.  Recommended first-line antibiotics include Augmentin, high-dose amoxicillin, and extended spectrum cephalosporins.  Surgery for acute or chronic rhinosinusitis is usually a last resort after maximal medical therapy has failed.

Odontogenic rhinosinusitis presents a unique challenge to the otolaryngologist.  The diagnosis is frequently delayed.  A dental source for the sinus infection is frequently not considered until after both medical and surgical therapy has failed to resolve the patient's symptoms and radiographic disease.  A primary cause for the delay in diagnosis is the failure of the radiologist and ENT physician to adequately assess dental pathology on CT imaging.  In a 2010 retrospective case series involving 21 patients with known odontogenic rhinosinusitis, the initial radiology report failed to mention radiographic findings of dental pathology in 14 or 67% percent of the patients (6).  There are symptoms which suggest an odontogenic source for the infection in patient presenting with rhinosinusitis.  First, the large majority of patients will present with unilateral symptoms.  This means that the patient will complain of nasal discharge, cheek pain, dental pain or nasal obstruction primarily on one side.  Another unique symptom to odontogenic rhinosinusitis is a foul smell noted by the patient.  In 76 patients with known odontogenic rhinosinusitis, 33 or 43% reported a foul smell (6,7,8).

In addition to early diagnosis, a successful outcome of odontogenic rhinosinusitis requires appropriate antibiotic therapy based on the common microbiology findings of a mixed polymicrobial infection.  Like other odontogenic-induced infections, first-line antibiotic coverage for ORS is clindamycin.  Additionally, successful treatment depends on eliminating the source of the infection.  This requires early involvement of the dental health professional.  In general, dental procedures take precedence over the ENT procedures.  Situations where ENT surgery would precede dental surgery include the following:

1. A complications of rhinosinusitis requiring emergent surgery.

2. Sinus surgery in an infected maxillary sinus performed prior to closure of an oral antral fistula to increase the chance of success.

3. Sinus surgery for pre-existing sinus disease prior to sinus augmentation (9).

The most important aspect of successful treatment consists of good coordination of care and communication between the dentist and ENT physician.

Case 1

A 51 year old female presents with one year of left facial & tooth pain, left nasal obstruction, postnasal drainage and headaches.  Past dental history is significant for RCT of teeth 10 & 11, apicoectomy of tooth #10, and dental implants #12 & 13.  The implants failed and she developed an oral antral fistula after removal of the implants and debridement of necrotic bone. Coronal CT image demonstrating severe left maxillary and ethmoid sinus disease. This one sided sinus disease was of odontogenic origin.

A coronal CT 2 months after ethmoid and maxillary sinus surgery showing complete resolution of sinus disease. 

Several months later, she underwent a successful sinus lift with implantation and a coronal CT image demonstrating ossification of the sinus augmentation.

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Case 2

A 70 year old male with postnasal drainage presents with a right nasal cavity mass demonstrated on nasal endoscopy. 

A yellow discharge is associated with the object.  A coronal CT image demonstrates extrusion of a dental implant 9.5mm into the right nasal cavity. 

Additional implants extruding into the maxillary sinuses without radiographic disease.

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Case 3

A 69 year old female presents with 12 months of brown-yellow nasal drainage, mild right facial pressure, right nasal congestion and a foul taste and smell.  She presented to her general dentist 3 months prior to her ENT consultation with a right gingival buccal lesion that resolved with clindamycin. A coronal CT image of the paranasal sinuses demonstrates maxillary and ethmoid sinusitis ipsilateral to right maxillary periapical tooth disease with buccal plate and maxillary sinus floor boney erosion.  

A sagittal image through the right maxillary sinus shows periapical disease of teeth #2 and 3.  This is another odontogenic sinusitis requiring dental treatment as the initial treatment for her sinus problem.   

Posted by: Tim Haegen MD of the Arizona Sinus Center

References

1.  Morbidity and cost of odontogenic infections.  Eisler L, Wearda K, Romatoski K, Odland RM.  Otolaryngol Head Neck Surg. 2013 Jul;149(1):84-8.

2.  Clinical aspects of odontogenic maxillary sinusitis: a case series.  Longhini AB. Ferguson BJ.  International Forum of Allergy & Rhinology. 1(5):409-15, 2011 Sep-Oct. 

3.  Lanza DC, Kennedy DW. Adult rhinosinusitis defined. Otolaryngol Head Neck Surg 1997;117:S1-7.

4.  ENT assessment in the integrated management of candidate for (maxillary) sinus lift. Pignataro L, Mantovani M, Torretta S, et al.  ActaOto rhino laryngolItal 28:110–119, 2008.

5.  Late signs and symptoms of maxillary sinusitis after sinus augmentation. Manor Y, Mardinger O, Bietlitum I, et al.OralSurg Oral Med Oral Pathol Oral RadiolEndod 110:e1–e4, 2010.

6.  Clinical aspects of odontogenic maxillary sinusitis: a case series.  Longhini AB. Ferguson BJ.  International Forum of Allergy & Rhinology. 1(5):409-15, 2011 Sep-Oct.  

7.  Microbiology of acute and chronic maxillary sinusitis associated with an odontogenic origin. Brook I. Laryngoscope. 115(5):823--‐5, 2005 May.

8.  Late signs and symptoms of maxillary Sinusitis after Sinus augmentation. Manor Y, Mardinger O, Bietlitum I, et al. Oral Surg Oral Med Oral Pathol Oral RadiolEndod 110:e1-e4, 2010.

9.  The characteristics and new treatment paradigm of dental implant-related chronic rhinosinusitis.  Chen YW, Huang CC, Chang PH, Chen CW, Wu CC, Fu CH, Lee TJ.  Am J Rhinol Allergy. 2013 May;27(3):237-44.