A rare cause of nasolacrimal duct obstruction: Dentigerous cyst in the maxillary sinus

The most common abnormality of the lacrimal drainage system is congenital or acquired nasolacrimal duct obstruction. The causes of acquired nasolacrimal duct obstruction may be primary or secondary. The secondary acquired obstructions may result from infection, in ﬂ ammation, neoplasm, trauma or mechanical causes. The maxillary sinus cysts usually obstruct the nasolacrimal duct mechanically. Dentigerous cysts are one of the main types of maxillary cysts. These cysts are benign odontogenic cysts which are associated with the crowns of unerupted teeth. The clinical documentations of mechanical nasolacrimal duct obstructions due to a dentigerous cyst in the maxillary sinus are very rare in literature. In this case report, we describe a dentigerous cyst with a supernumerary tooth in the maxillary sinus in an 11-year-old male child causing an obstruction to the nasolacrimal duct. The case was successfully managed surgically by Caldwell Luc approach. The use of contact lens (CL) for the correction of refractive errors, cosmetic use and their usage as a therapeutic modality for corneal pathologies has increased tremendously over the years. The present study was conducted with the aim to ﬁ nd a pa tt ern of CL use amongst college students with a focus on the rationale for CL use and problems related to their use. This study includes 371 college students who were current users of CL at the time of the study. Results showed that 96.8% of the CL users use the ‘daily wear type’ of CL. Most quoted reasons of usage were comfort and convenience (61.2%) with cosmetic benefit (42.9%) as the next most common reply. Common complaints were that of general discomfort (foreign body sensation), dry eyes and watering eyes. Educated use of CLs amongst its users is advised in view of the symptoms and associated complications that may occur.

Acquired secondary nasolacrimal duct (NLD) obstruction may result from infection, infl ammation, neoplasm, trauma or mechanical causes. [1] The mechanical obstruction of NLD by a dentigerous cyst in the maxillary sinus has been rarely documented in literature. [2,3] NLD obstruction presents commonly with epiphora and acute or chronic dacryocystitis. [2] We herein report this unusual case which presented to us with epiphora due to complete NLD obstruction by a dentigerous cyst containing a supernumerary tooth in the maxillary sinus.

Case Report
An 11-year-old male child was referred to us for epiphora. He had intermitt ent mucoid discharge from the inner canthus of the left eye for the last one year. Ocular and medical histories were normal. On examination, his best-corrected visual acuity was 20/20 in both eyes. Pupillary refl exes and extraocular movements were normal. Intraocular pressures were 16 mm of Hg in both eyes. Slit-lamp and funduscopic examinations were normal. On compression of the left lacrimal sac mucoid material regurgitated from the puncta. Lacrimal sac syringing revealed regurgitation of fl uid from the opposite punctum and hard stop with probing, suggestive of NLD obstruction. Radiograph of the paranasal sinuses showed opacified left maxillary antrum with a retained tooth near its roof [ Fig. 1]. A plain computed tomography (CT) scan of the orbits and paranasal sinuses was done by taking 2-mm axial and 3-mm coronal slices. The CT images were suggestive of a maxillary sinus cyst close to the orbital fl oor with the crown of the aff ected tooth projecting into it [ Fig. 2]. The cystic mass was pushing the naso-antral wall into the nasal cavity and compressing the NLD. There was no compression of the globe. Left dacryocystogram showed inability of the contrast medium to pass beyond the lacrimal sac [ Fig. 3]. Orthopantogram (OPG) detected the presence of a supernumerary tooth in the left maxillary antrum [ Fig. 4]. Our colleagues of the ENT department were consulted for management of the cyst in the maxillary sinus. Their examination revealed congested left nasal cavity with grossly restricted airway and bulging of the lateral wall of the left nose. There was no missing tooth. Removal of the cyst was planned by Caldwell Luc's approach. The outer part of the antero-lateral wall of maxilla was thin and its removal exposed the tense cyst wall. About 8 ml of purulent The maxillary sinus walls were found to be intact. Aspirated material on culture was found to be sterile. The postoperative course was uneventful and his symptoms resolved promptly. Postoperative left dacryocystogram revealed free fl ow of the contrast medium into the nose [ Fig. 6]. On six months followup the child remained asymptomatic.

Discussion
Nasolacrimal duct (NLD) obstruction may occur due to congenital or acquired causes. Acquired obstruction may be primary or secondary, complete or partial. Primary obstructions are idiopathic and secondary obstructions may be due to infection, infl ammation, neoplasm traumatic or mechanical causes. [1] Mechanically, a maxillary sinus cyst can obstruct NLD. The diff erent types of maxillary cysts are antral mucoceles, retention cysts, pseudocysts and dentigerous cysts. [3] Dentigerous cysts are usually solitary, benign odontogenic cysts associated with the crowns of unerupted teeth. [4] The accumulation of fl uid between the unerupted tooth and the surrounding dental follicle is the accepted etiology of the cyst. Third molars followed by maxillary canines (the most commonly impacted teeth) and only occasionally supernumerary teeth or odontomas are involved in cyst formation. [5] Supernumerary or ectopic tooth in the maxillary sinus is rare. [2,6] The common presentations of dentigerous cysts are facial swelling, delayed tooth eruption, recurrent head and neck infections.
As the cyst enlarges it expands the maxillary sinus and presses over the adjacent structures. In our case the dentigerous cyst was compressing the NLD. The easiest way to remove a dentigerous cyst is through a Caldwell Luc approach. [7] In this approach a window of adequate size is created on the anterior wall of the maxilla to deliver the cyst along with the impacted tooth. Though CT scan diff erentiates between a cyst and a tumor, aspiration with a 16/18-gauge needle can be done for confi rmation. [8] Enucleation of the cyst usually results in complete resolution of symptoms without evidence of recurrence. [2,9] If the obstruction persists aft er surgery for Brief Communications maxillary cyst, a dacryocystorhinostomy is needed as a bypass procedure. [3] Despite the possibility of dentigerous cysts of maxillary sinus causing NLD obstruction, aft er extensive MEDLINE search, we observed that only four cases have been reported so far. [2,3,9] In 1997 Altas et al. [9] reported a case of a large dentigerous cyst with a canine tooth in the right maxillary antrum causing NLD obstruction. In 2000 Alexandrakis et al. [2] reported two cases of NLD obstruction by an ectopic maxillary sinus and intranasal tooth. In 2003 Bajaj et al. [3] reported a case of dentigerous cyst in the maxillary sinus with NLD obstruction.
We conclude that the possibility of ectopic eruption of teeth should be kept in mind while evaluating a case of secondary NLD obstruction.

Unnikrishnan B, Shakir Hussain
The use of contact lens (CL) for the correction of refractive errors, cosmetic use and their usage as a therapeutic modality for corneal pathologies has increased tremendously over the years. The present study was conducted with the aim to fi nd a patt ern of CL use amongst college students with a focus on the rationale for CL use and problems related to their use. This study includes 371 college students who were current users of CL at the time of the study. Results showed that 96.8% of the CL users use the 'daily wear type' of CL. Most quoted reasons of usage were comfort and convenience (61.2%) with cosmetic benefit (42.9%) as the next most common reply. Common complaints were that of general discomfort (foreign body sensation), dry eyes and watering eyes. Educated use of CLs amongst its users is advised in view of the symptoms and associated complications that may occur.

Key words: Contact lens, India, Karnataka, students
Indian J Ophthalmol: 2009;57:00-00*** DOI: **** Popularity of contact lens (CL) continues to increase with regular improvement in materials and variants suitable for a variety of users. [1] The ideal CL for refractive errors has proved diffi cult to fi nd with reports of complications with even the most advanced systems available. [2][3][4] Recent studies have shown the use of CL for refractive error correction to be higher and more common among the younger strata of population. [5][6][7] Complications most commonly associated with use include dry eye, giant papillary conjunctivitis, corneal abrasion, corneal edema, corneal ulcer, keratitis and neovascularization. [8] The awareness of these complications was found lacking amongst the younger users and 87% of these users preferred CL use in spite of the ocular problems related to their use. [9] Cosmetic benefits and convenience were the most common reasons cited for CL use. [5,6] Knowledge about use patt ern would prove useful to general ophthalmologists and optometrists in guiding young prospective users in lens type, hygiene and patt ern of use. The aim of this study was to fi nd a patt ern of CL use amongst college students with a focus on the rationale for CL use and problems related to their use.

Materials and Methods
The present cross-sectional study was carried out in 18 colleges of coastal Karnataka comprising two districts, namely Dakshina Kannada (Mangalore) and Udupi.
The sample size was calculated based on the previous pilot study in which 60% of the CL users had symptoms associated with CL use, the minimum sample size was found to be 369 CL users with precision of 5%, power of 80% and 95% confi dence interval. The study population consisted of 6850 college students from 18 diff erent colleges in coastal Karnataka. These students were surveyed about their CL use, out of which 392 students were currently using CLs, 21 students declined to participate in the study and the fi nal