Patient-Specific Implants (PSI) in Maxillary Hypoplasia Secondary to Cleft Lip and Palate Deformity

Abstract

Maxillary hypoplasia is often evident in cleft patients due to impaired growth and dense scarring from previous cleft surgeries. For these patients, treatment scenario has taken many turns over ages, evolved from orthognathic correction to distraction osteogenesis, with mixed prognosis and outcome depending on severity of the case and other several factors. We are reporting a case of 24-year-old female with maxillary hypoplasia secondary to bilateral cleft lip and palate with hypoplastic prolabium, who has been treated with two patient-specific implants in bilateral maxillary region for facial profile enhancement.

Introduction

Craniofacial anomalies and secondary deformities have always been psychologically traumatising even if being surgically repaired optimally to establish the function and aesthetics. The patients are likely to go through several surgeries till and beyond the growth age, and this leaves the infancy and childhood psychologically scarred for many of them, making them to quit and settle for easier or less invasive treatment options. For patients with cleft lip and palate, this battle starts with primary cleft lip and palate repairing surgeries and when 25–60% [1–3] of these patients eventually develop maxillary hypoplasia and malocclusion, again they are required to go through surgical interventions for correction of this secondary deformity. Over the decades, this particular group of patients have been majorly treated with orthognathic surgery (Le Fort I advancement osteotomy) [4–7], often with distraction osteogenesis (DO) in maxilla [8–10] and sometimes in combination of both. Depending on severity of the deformity, the results have always ranged from favourable to unfavourable, with questionable predictability. Amidst these popular treatment choices, we are reporting a case of maxillary hypoplasia secondary to primary cleft lip and palate surgery, who was previously tried with DO without much success. We treated the patient with two (left and right) patient-specific implants (PSI) to enhance the hypoplastic maxilla bilaterally.

Case Report

A 24-year-old female reported to the outpatient department with a complaint of sunken middle part of face. Born with bilateral cleft lip and palate, she mentioned to have had previous surgeries for cleft repair in lip and palate and gave a history of failed attempt at distraction osteogenesis in the midface tried elsewhere. Also, she had undergone open method rhinoplasty using conchal cartilage along with L-shaped silicon nasal implant for columella and dorsum augmentation, with improved aesthetic result. However, she was not satisfied with her midface, yet, not willing to undergo any invasive procedure.

On examination, scarring in the philtrum columns and lower lip was noticed, suggestive of previous cleft lip surgeries, including one with Abbe’s flap from the lower lip. With a reduced nasal projection and partially competent nostrils, she presented with a concave facial profile (Fig. 1a–c).

Fig. 1.

Pre-operative frontal (a), three-quarter (b) and lateral (c) facial photographs

Intra-oral examination revealed Class I molar relationship with satisfactory occlusion. She had a history of orthodontic treatment.

On radiographic examination, maxilla of both the sides was found to be hypoplastic.

High-resolution CT images (1 mm slice) were obtained, converted to DICOM format and sent to the PSI manufacturing laboratory for fabrication of stereolithographic model of the existing deformity and subsequent fabrication of PSI.

Two non-identical side-specific (left and right) PSI were fabricated for maxillary enhancement. Implants were manufactured by subtraction technique via a CNC machine from medical grade titanium block (Fig. 2a, b).

Fig. 2.

Titanium made non-identical side-specific (left & right) PSI on stereolithographic model (a); PSI on software interface (b)

Under general anaesthesia, the implants were fixed through maxillary vestibular approach (Fig. 3a, b).

Fig. 3.

Intra-operative photographs showing the PSI fixed in the hypoplastic right (a) and left (b) maxillae

Postoperative outcome has been satisfactory, and the patient has been followed up for 1.5 years now (Fig. 4a–c).

Fig. 4.

Post-operative orthopantomogram showing the fixed PSI in maxilla (a); before/after comparison in lateral and three-quarter facial view depicting post-operative midfacial enhancement (b); post-operative facial photographs in lateral, three-quarter and worm’s eye view (c)

Discussion

With the advent of new surgical techniques and protocols by different clinicians and institutional bodies, for patients with maxillary hypoplasia secondary to cleft lip and palate, the orthognathic correction has always been advocated since a long time. However, this also has its perils. As the previous corrections of cleft palate leave dense scar tissue, many a times the advancement of the distal segment becomes challenging during a Le Fort osteotomy [11–15]. And for those cases where major advancement is required, they often may need interpositional autologous bone grafting and, therefore, include further invasive procedure and donor-site morbidities [16]. Infection, graft resorption, etc., often being the secondary postoperative complications, skeletal relapse is still remaining the primary concern for these patients pertaining to already scarred surgical site due to previous cleft repair surgeries [2, 7, 11–15].

Over the time, when DO took its turn from long bones to mandible [17] and eventually to the entire craniofacial skeletal system, some of the authors vehemently advocated DO for maxillary advancement as this offered amelioration of the disadvantages Le Fort I osteotomy had posed. As DO offered simultaneous soft tissue adaptation along with gradual skeletal advancement, it demonstrated less relapse compared to orthognathic [9, 10, 18]; moreover, it also did not include bone grafting, leaving room for less morbidity.

In cleft patients, if the advancement following maxillary Le Fort osteotomy is exceeding 9 mm, velopharyngeal closure is reported to be compromised, resulting in postoperative borderline incompetence to complete velopharyngeal insufficiency [19, 20], whereas maxillary DO up to 15 mm does not markedly influence velopharyngeal function [21, 22].

Conventional orthognathic surgeries can only be carried out at the cessation of skeletal growth after puberty has ended, whereas DO can be performed in growing children with retruded maxilla secondary to cleft palate, which surely brings a positive psychological effect in patients and their parents.

However, DO is challenging itself and demands more innovation to negate its own disadvantages. For patients who are apprehensive and uncomfortable towards fixing extra-oral multivectorial distraction devices like rigid external distractor (RED), they are often treated with intra-oral devices, seldom leading to less predictable outcome due to less control over vector lengthening and limited distraction length [23, 24]. Also, the conventional intra-oral devices need to be removed in a second surgery unlike the extra-oral ones that are easily removed just by unlocking the fixation rods.

The idea of patient-specific implants (PSI) arises to reduce co-morbidities and unpredictability of treatment outcome with autologous or other grafts, for precise and predictable adaptation and restoration of facial anatomical features. Furthermore, alloplastic biomaterials do not resorb over time which gives stable and predictable outcome [25, 26].

Having been used to reconstruct cranial vault deformities, it has established its own place in craniofacial reconstruction. The invent of CAD-CAM 3D printing had brought revolution in both the field of navigation surgery using stereolithographic template and the field of bony reconstruction and soft tissue simulation [27, 28].

Titanium being the gold standard has been used for ages due to its biocompatibility, strength to weight ratio and osseo-integrative property [29]. PEEK and Medpore are also popularly used as alloplastic implants in maxillofacial reconstruction [30, 31]. In our case, we have used PSI to enhance the maxillary region bilaterally. Subtractive machining technique was employed to fabricate the PSI from titanium blocks following precise evaluation with a stereolithographic model of the existing deformity.

Postoperatively, the patient has been followed for 1.5 years now, without any complication. After the surgery, the facial profile, nasolabial areas and the overall midfacial region are evidently augmented.

Conclusion

Orthognathic surgery and distraction osteogenesis are conventional as well as time-tested modalities of treating midface hypoplasia in cleft patients; but sometimes due to previous failed surgeries or unsatisfactory result, we have to think of other alternatives. Since many of these patients are young adults, they would prefer quick and less surgically invasive results for psycho-social reasons. PSI have been in use in maxillofacial reconstruction for trauma and ablative surgeries with predictable outcomes, and in our case, we got satisfactory result with PSI in a very short time with a minimally invasive surgery. However, more cases and long-term follow-up are required to consider it as viable alternative to Le Fort I advancement osteotomy or distraction osteogenesis.