Prevalence of Maxillary Lateral Incisors and Eruptive Direction of Maxillary Canine in Japanese Unilateral Cleft Lip and Alveolus and Unilateral Cleft Lip and Palate Patients

Special Article - Oral and Maxillofacial Surgery

J Dent & Oral Disord. 2016; 2(9): 1045.

Prevalence of Maxillary Lateral Incisors and Eruptive Direction of Maxillary Canine in Japanese Unilateral Cleft Lip and Alveolus and Unilateral Cleft Lip and Palate Patients

Kajii TS¹*, Takamura Y¹, Hata S¹, Nukumizu K², Tamaoki S¹, Takagi S³, Ohjimi H³ and Ishikawa H4

¹Section of Orthodontics, Department of Oral Growth & Development, Division of Clinical Dentistry, Fukuoka Dental College, Japan

²Section of Oral & Maxillofacial Surgery, Faculty of Medicine, University of Miyazaki, Japan

3Department of Plastic, Reconstructive, & Aesthetic Surgery, School of Medicine, Fukuoka University, Japan

4Fukuoka Dental College, Japan

*Corresponding author: Takashi S. Kajii, Section of Orthodontics, Department of Oral Growth & Development, Division of Clinical Dentistry, Fukuoka Dental College, Fukuoka, Japan

Received: October 26, 2016; Accepted: November 15, 2016; Published: November 17, 2016

Abstract

Purpose: The aim of present study was to confirm prevalence of the lateral incisor in Japanese unilateral cleft lip and palate or alveolus patients. The present study also hypothesized that a congenitally missing maxillary lateral incisor in the lesser segment may affect eruptive direction of the maxillary canine on the cleft side.

Methods: Participants comprised 40 Japanese oral cleft patients (23 patients with non-syndromic Unilateral Cleft Lip and Palate (UCLP), 17 patients with nonsyndromic Unilateral Cleft Lip and Alveolus (UCLA)). Panoramic radiographs taken at initial examination were used to assess the maxillary lateral incisor and measure maxillary canine angulation. Additionally, maxillary canine angulation of 20 subjects who had undergone secondary autologous bone grafting was also measured using panoramic radiographs taken after canine eruption.

Results: Frequency of a congenitally missing lateral incisor on the cleft side was 52% in UCLP patients and 24% in UCLA patients. Maxillary canine angulation during eruption on the cleft side was inclined significantly more mesially in subjects without a maxillary lateral incisor at the lesser segment than in subjects with the lateral incisor.

Conclusions: Frequency of a congenitally missing lateral incisor on the cleft side in Japanese UCLP patients was double that in UCLA patients. Presence of the maxillary lateral incisor in the lesser segment may guide the maxillary canine to a more vertical eruptive direction, although a maxillary canine located near the cleft without a lateral incisor in the lesser segment may appear to erupt at the same angle held before grafting.

Keywords: Canine; Cleft lip; Cleft palate; Lateral incisor

Abbreviations

SBG: Secondary alveolar Bone Grafting; UCLP: Unilateral Cleft Lip and Palate; UCLA: Unilateral Cleft Lip and Alveolus

Introduction

Oral clefts are one of the most common congenital craniofacial anomalies, and oral cleft patients usually require orthodontic treatment. Malpositioning of teeth adjacent to the cleft, such as rotation and tipping, and dental abnormalities such as hypodontia, malformation, abnormal eruption patterns are frequent in cleft patients [1-3]. A congenitally missing maxillary lateral incisor on the cleft side is the most common finding in cleft patients [4-7].

Bony and soft tissue cleft defect, lesser segment dimensions, alveolar bone grafting, tooth size, as well as dental anomalies including supernumerary, congenitally missing, or malformed teeth, may alter dental eruption patterns and could increase the risk of dental impaction in cleft patients [8-12]. These factors make orthodontic treatment planning difficult [13-16].

During normal eruption in non-cleft children, the canine displaces toward the occlusal plane, straightens gradually, and deviates toward a more vertical position [17-19]. Gereltzul et al. [20] reported that the maxillary canine on the cleft side tips more mesially than that on the non-cleft side in cleft patients. They also reported that a maxillary canine located near the cleft with Secondary Alveolar Bone Grafting (SBG) appears to erupt at the same angle held before grafting, although without SBG the canine erupts more vertically, guided by cortical bone. However, most patients with cleft alveolus now undergo SBG. Existence of a maxillary lateral incisor in the lesser segment may also guide the maxillary canine in a more vertical eruptive direction, but few studies have evaluated the influence of the status of the maxillary lateral incisor on eruption of the cleft-side canine.

In oral cleft patients, understanding the prevalence of the lateral incisor can help in making orthodontic treatment plans for patients. The aim of the present retrospective study was to confirm the prevalence of the lateral incisor for Unilateral Cleft Lip and Palate (UCLP) and Unilateral Cleft Lip and Alveolus (UCLA) patients in the Japanese population. The present study also hypothesized that a congenitally missing maxillary lateral incisor in the lesser segment would affect the eruptive direction of the maxillary canine on the cleft side.

Materials and Methods

Subjects

Forty Japanese oral cleft patients (23 patients with non-syndromic UCLP, 17 patients with non-syndromic UCLA) were examined (Table 1). Criteria for including UCLP or UCLA subjects in the study were: 1) intention to be treated at the Orthodontic Clinic of Fukuoka Dental College Medical and Dental Hospital between 2000 and 2015; 2) age <10 years at initial examination; 3) no eruption of canines at initial examination; and 4) no alveolar bone grafting at initial examination. Criteria for excluding a subject from the study were: 1) incomplete cleft lip and alveolus; 2) history of trauma; and 3) previous orthodontic treatment.