About 10% of patients diagnosed with RMS in the head and neck have orbital involvement.[17] Orbital RMS usually affects younger children under 10 years of age.[3–18] Rees (2022) observed, in a retrospective cohort in the US population-based cancer registry from 2000 to 2016, 1154 children aged between 0 to 9 years were diagnosed with RMS. Tumors located in the head and neck region affected 247 children and 97 (39.27%) were in the orbit. A total of 662 were male (57.4%) and 492 female (42.6%), and most reported histopathological classification was embryonal/other with 893 (77.38%) cases and alveolar with 261 cases (22.61%).[4] In this study the percentage of orbital RMS was lower only eight (29.62%), of the 27 patients with RMS in the head neck agreed to participate in the study.
Imaging evaluation in RMS patients is important to guide staging, planning local treatment, and monitoring recurrences.[37] In orbital RMS, imaging studies usually show a single unilateral orbital lesion in the retrobulbar region; in larger tumors, there may be a bone alteration, such as erosion of the adjacent orbital walls, and in these cases, the parameningeal is considered the primary site (orbit with bone erosion).[8–37–13] In this study, the primary disease site was the orbit in seven (87.5%) cases and parameningeal (orbit with bone erosion) in one case(12.5%).
Multimodal treatment (surgery, chemotherapy and radiotherapy) applied at a young age usually implies significant bone and dental late alterations.[3] In a cross-sectional study, Stolze et al.(2021), evaluated 154 survivors of childhood cancer diagnosed between 1963 and 2001. Prevalence and independent risk factors for long-term cancer treatment effects were identified. Of those patients, 36.3% had at least one dental alteration. The most prevalent of them were root shortening (14.6%), agenesis (14.3%), and microdontia (13.6%). Risk factors associated with these dental alterations were younger age at diagnosis (< 3 years) and therapy with dose-dependent alkylating agent.[26]
Halperson et al. (2022), in an observational cross-sectional study, evaluated the prevalence of dental development anomalies (DDA) among childhood cancer survivors according to types of cancer treatment, examining 121 adolescents. DDA was observed in 56 (46%) individuals and in 309 (9%) of the 3388 total teeth analyzed. Enamel hypomineralization or hypoplasia was observed in 21 (17%) patients, altered root development in 26 (21.5%), and hypodontia in 13 (10%). DDA was observed in 36 (43%) subjects submitted only to chemotherapy, in 20 (52%) submitted to radiotherapy, and in 15 (60%) of those who received head and neck radiotherapy. Among patients who received only chemotherapy, younger age (6 years or less) was associated with a greater number of malformed teeth.[44]
These data are in agreement with this study, where multimodal treatment was applied and most subjects (6 patients) received VAC protocol as chemotherapy, and 2 received a combination of VAC, ifosfamide, and etoposide. Most dental abnormalities (75 abnormalities − 51.36%) were in the upper left quadrant, where the highest number of affected orbits were located (5 patients with tumors in the left orbit); this demonstrates the deleterious effect of local treatment radiotherapy (RT). The mandible teeth also had significant dental alterations (left and right lower quadrant), where 30 (20.54%) dental alterations were detected. This leads to suspicion that it was related to chemotherapy
(CT) that included alkylating agents, since the mandible was located outside the irradiation field.
Considering the population with ages between 0 to 10-year-old during treatment (87.5%), six (75%) children less than five-year-old at the time of treatment presented the highest frequency of dental alterations. ( p= )In young children, teeth and bones are in developmental process, and cancer treatment at this age could result in important late dental and bone alterations, mainly in the region of the treated orbit.
Eade et al. (2017) presented a retrospective study of late complications in 18 patients with pediatric orbital RMS treated with chemotherapy and radiotherapy. They reported ocular complications in both orbital and paranasal groups, in 42% of cases as well as orbital hypoplasia (facial asymmetry secondary to orbital hypoplasia) or fatty atrophy.[45]
Hol et al. (2020), in their study, quantified orbital asymmetry in survivors of orbital RMS and characterized the effect of radiotherapy dose on orbital bones. On follow up magnetic resonance imaging (MRI) examination, it was observed in 16/17 patients that the ipsilateral orbital volume was significantly smaller than the contralateral (P ≤ 0.0001). A dose greater than 40 Gy to all marginal orbital bones was associated with significant decrease in orbital volume (P < 0.05).[46] In this photographic study, asymmetrical facial features were observed in seven (87.5%) individuals. Furthermore, according to cephalometric analysis, five (62.5%) patients had reduced facial depth and height. (Table 4 and Figs. 1 and 2).
In conclusion, orbital RMS patients treated with chemotherapy (CT) and radiotherapy(RT), important dental and facial bone alterations were found. As expected, the most significant were in the maxilla and close to the irradiation field. Dental and mandibular bone alterations were also found, indicating the probable chemotherapy action, as this region was not included in the irradiation field.
A limitation of the study was the small number of patients included, as only patients who were alive and who consented to participate in the study could be studied. Even so a high frequency of bone and dental alterations were observed.