Nasolacrimal duct injury after Le Fort I osteotomy

Evaluation of nasolacrimal canal morphology in different facial skeletal relationships

BACKGROUND

Abnormal morphological variations of nasolacrimal canal (NLC) and its lack of understanding contributes to acquired injuries during craniomaxillofacial surgical procedures which leads untoward postoperative complications like nasolacrimal obstruction (NLO) and epiphora.

PURPOSE

The purpose of this study was to determine dimensional and volumetric morphological variations of nasolacrimal canal in various facial skeletal relationships which aid in performing a precise and safe surgery.

MATERIALS AND METHODS

This retrospective cohort study involved dimensional and volumetric analysis of nasolacrimal canal procured from computed tomography scans of 47 individuals grouped as ClassI, Class II and Class III, and unilateral cleft lip and palate (UCLP) groups. The outcome variables included length of NLC, volume of NLC, distance between the inferior orifice of the NLC to nasal floor, distance between inferior orifice of NLC to canine apex and distance between inferior orifice of NLC to central incisor apex. The objectives were to analyse morphological variation of NLC in different facial skeletal relationships and to evaluate the variation with change in facial sides and its relationship with surrounding structures.

RESULTS

Volume of the NLC was found significant in Class I and UCLP population (p < 0.05) with the greatest volume in the UCLP group. The mean linear and volumetric measurements between the right and left sides were found insignificant among all groups. Inferior orifice of NLC from canine apex were farthest in Class III and nearest in the UCLP group (p < 0.05). There was no significant association between outcome variables and skeletal base configuration.

CONCLUSION

NLC demonstrates dimensional and anthropometric variations between different skeletal relationships and this study is inevitable in understanding the probability of NLC injury during maxillofacial surgeries.

Bony nasolacrimal duct dehiscence in functional endoscopic sinus surgery: radiological study and discussion of surgical implications

OBJECTIVES

To analyse the radiological features of the bony nasolacrimal duct before and after functional endoscopic sinus surgery, and document the incidence of surgically induced dehiscence.

METHODS

A retrospective case series analysis was conducted of 63 consecutive patients who underwent uncinectomy as a part of 118 functional endoscopic sinus surgical procedures. All patients underwent pre- and post-operative computed tomography scans. Axial computed tomography images at the level of maxillary sinus were evaluated for the presence of bony nasolacrimal duct dehiscence, osteitis and completeness of uncinectomy.

RESULTS

The rate of nasolacrimal duct dehiscence prior to surgery was 6.8 per cent (8 out of 118 cases). Nasolacrimal duct dehiscence as a consequence of surgery was observed in 3.3 per cent of cases (4 out of 118), with a further 4.2 per cent (5 out of 118) showing post-operative reactive bony change of the nasolacrimal duct in the absence of dehiscence.

CONCLUSION

The incidence of nasolacrimal duct injury observed was much lower than that previously reported in the literature.

Anatomic relationship of nasolacrimal duct and major lateral wall landmarks: cadaveric study with surgical implications

BACKGROUND

Detailed knowledge of the surgical anatomic landmarks of the lateral nasal wall is important for safe and successful endoscopic sinonasal surgery. We sought to determine the relationship of major landmarks to the nasolacrimal duct (NLD).

METHODS

Twenty mid-sagittal head sections of 10 fresh frozen cadavers were studied after removal of the nasal septum. The insertion of the alar cartilage into the maxilla was taken as a fixed point and all measurements were performed in a defined axial plane at the level of the maxillary sinus natural ostium. Two surgeons independently recorded each measurement 3 times with an average of the readings used for statistical analysis.

RESULTS

The overall agreement index was excellent (r = 0.84) between the observers. At the level of maxillary ostium, the mean distance from the alar rim to the NLD was 43.05 ± 4.76 mm on the right and 41.25 ± 4.56 mm on the left. The most anterior projection of the middle turbinate head was noted to be anterior to the NLD in 70% of specimens. In positional relationship, the maxillary line was posterior to the NLD in 55%, whereas the bulla ethmoidalis and the free edge of uncinate process were uniformly posterior to the NLD in all the specimens.

CONCLUSION

This study provides useful anatomic and positional relationships between the NLD and major lateral wall landmarks. Although the maxillary line and the head of the middle turbinate are often considered useful guides to the position of the ipsilateral NLD, their spatial relationship to the NLD is not consistent. These landmarks, therefore, cannot be solely relied upon during surgery to avoid injury to the NLD.

Screw implantation in the globe: the risk of delayed hardware migration from craniofacial repair

Plating system modification has enabled the use of rigid fixation in younger patients having maxillofacial surgery. One of the common reported complications of the use of plates and screws in children is screw migration due to skeletal maturation. Ophthalmic complications due to maxillofacial surgery reported to date include oculomotor and abducens palsies, lacrimal damage and vision loss due to infection, retrobulbar hemorrhage, and compartment syndrome. We describe a complication unique to screw migration resulting in orbital fixation and near-globe rupture in a patient with Treacher Collins syndrome. We hope to alert our colleagues to the potential risk of screw and hardware migration and breakage, particularly in the setting of craniofacial surgery performed on a child before maturation of craniofacial osseous structures.

Nasolacrimal duct obstruction after maxillary orthognathic surgery

PURPOSE

To report cases of nasolacrimal duct obstruction (NLDO) after maxillary orthognathic surgery.

MATERIALS AND METHODS

The authors reviewed the clinical manifestations, dacryocystographic images, and orbital computed tomographic scans of 10 patients who were diagnosed with NLDO after undergoing maxillary orthognathic surgery.

RESULTS

Six of the 10 patients (60%) complained of epiphora immediately after the surgery. Bilateral (n = 2, 20%) or unilateral (n = 8, 80%) NLDO occurred in all patients involved in the study. Twelve eyes of 10 patients were examined, and dacryocystography showed that the obstruction was present in the distal ostium in 7 eyes (58.3%), the junction between the sac and duct in 3 eyes (25%), and the common canaliculus in 2 eyes (16.7%). Computed tomographic scans of all subjects showed that mucosal swelling and congestion around the distal NLD opening narrowed the space between the lateral nasal wall and the inferior turbinate of the affected side. Dacryocystorhinostomy was performed in 9 eyes (8 patients), with a success rate of 100%.

CONCLUSIONS

The distal to proximal portion of the NLD can become obstructed after maxillary orthognathic surgery. This obstruction seems to be caused by secondary inflammatory changes associated with an indirect injury of the NLD. Therefore, clinicians should be aware of the possibility of NLDO after orthognathic surgery, which can be treated successfully with dacryocystorhinostomy.

Topography of the nasolacrimal duct on the lateral nasal wall in Koreans

PURPOSE

The aim of this study was to describe in detail the gross anatomy of the nasolacrimal apparatus in relation to the lateral nasal wall by the various steps of cadaver dissection and to measure the distances of surgically important landmarks from relevant structures to improve the safety and efficiency of endoscopic surgical procedures.

METHODS

Thirty-six half-heads of embalmed Korean adult cadavers were dissected under a surgical microscope. After removal of the nasal septum, the lateral wall of the nasal cavity was examined.

RESULTS

The orifice of the nasolacrimal duct (NLD) was most frequently observed in the form of a vertical sulcus in 14 cases (39%) and the lacrimal fold was present in 28 cases (77.8%). A total of 15 morphometric items between the orifice of the NLD and the adjacent anatomical structures were measured. The location of the orifice of the NLD was observed at a mean of 17.5 ± 3.1 mm from the limen nasi, 22.8 ± 4.8 mm from the anterior nasal spine, and 21.4 ± 3.5 mm from the axilla of the middle nasal concha. In the positional relationships, the most frequent finding was that the lacrimal sac was posterior to the axilla of the middle nasal concha in 23 cases (64%), and overlap of the NLD with the maxillary line was observed in 24 cases (67%).

CONCLUSIONS

This study was conducted to accumulate anatomic data on the lacrimal sac and duct with regard to the positional relationships among the surrounding structures to establish the information for use in endoscopic dacryocystorhinostomy.